[Federal Register Volume 69, Number 158 (Tuesday, August 17, 2004)]
[Notices]
[Pages 51112-51128]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-18731]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-413 AND 50-414]
Duke Energy Corporation; Concerning the Application for
Irradiation of Mixed Oxide Lead Test Assemblies at Catawba Nuclear
Station, Units 1 and 2; Environmental Assessment and Finding of No
Significant Impact
The U.S. Nuclear Regulatory Commission (NRC) is considering
issuance of an amendment to the Facility Operating Licenses to permit
the use of mixed oxide (MOX) lead test assemblies (LTAs) in one of the
two Catawba units and is considering the granting of exemptions from
(1) the requirements of Title 10 of the Code of Federal Regulations (10
CFR) Part 50.44(a), 10 CFR 50.46(a)(1) and 10 CFR Part 50, Appendix K
with respect to the use of M5\TM\ fuel rod cladding; (2) 10 CFR
50.46(a)(1) and Appendix K to Part 50 with respect to the use of MOX
fuel; and (3) certain physical security requirements of 10 CFR Parts 11
and 73 that are usually required at fuel fabrication facilities for the
protection of strategic quantities of special nuclear material. A
similar request for an exemption from the requirements of 10 CFR Part
50.44(a) with respect to the use of M5\TM\ fuel rod cladding is not
being granted since 10 CFR Part 50.44 has been changed and an exemption
from it is no longer necessary. The amended license and exemptions
would apply to Renewed Facility Operating License Nos. NPF-35 and NPF-
52, issued to Duke Energy Corporation (Duke, the licensee), for
operation of the Catawba Nuclear Station, Units 1 and 2, (Catawba)
located in York County, South Carolina. Therefore, pursuant to 10 CFR
51.21, the NRC is issuing this environmental assessment (EA) and
finding of no significant impact (FONSI).
1.0 Introduction
The NRC staff has organized the discussion and evaluation to
provide users with the context of the proposed action, supporting
information that is available for tiering, the independent analyses
performed, technical bases, and NRC conclusions. The following
[[Page 51113]]
structure was crafted to aid in its presentation:
1.0 Introduction
2.0 Background
3.0 Need for and Description of the Proposed Action
4.0 Non-Radiological Environmental Impacts of the Proposed Action
5.0 Radiological Environmental Impacts of the Proposed Action
6.0 Irreversible or Irretrievable Commitment of Resources
7.0 Unavoidable Adverse Impacts
8.0 Mitigation
9.0 Cumulative Impacts
10.0 Alternatives to the Proposed Action
11.0 Agencies and Persons Consulted
12.0 References
13.0 Finding of No Significant Impact
On the basis of the EA that follows, the Commission concludes that
the proposed action will not have a significant effect on the quality
of the human environment. Accordingly, the Commission has determined
not to prepare an environmental impact statement (EIS) for the proposed
action.
By letter dated February 27, 2003, as supplemented by letters dated
September 15, September 23, October 1 (two letters), October 3 (two
letters), November 3 and 4, December 10, 2003, and February 2 (two
letters), March 1 (three letters), March 9 (two letters), March 16 (two
letters), March 26, March 31, April 13, April 16, May 13, and June 17,
2004, Duke submitted a license amendment request that, if granted,
would authorize the irradiation of four mixed uranium and plutonium
oxide MOX LTAs at either Catawba, or McGuire Nuclear Station (McGuire),
Units 1 and 2, to support the U.S. Department of Energy (DOE) program
for the disposition of fissile material. The DOE is responsible for
implementing the national policy for disposition of fissile material.
Duke has requested that the NRC staff's review only consider Catawba,
as the proposed action because it no longer needed the option of
conducting an LTA irradiation program at McGuire (Reference 6). In a
previous, separate licensing action to support the renewal of the
operating licenses for Catawba, Duke provided an environmental report
(ER) (Reference 3); the ER provides useful background information about
the site and its environs.
The proposed action involves issuance of three exemptions (for the
use of M5\TM\ cladding, instead of zircaloy; for fuel in the form of
mixed uranium and plutonium oxide, rather than uranium oxide; and from
certain physical security requirements usually required at fabrication
facilities for the protection of strategic quantities of special
nuclear material) and a license amendment for accompanying changes to
the Catawba Technical Specifications (TSs) contained in Appendix A of
each of the Catawba Nuclear Station operating licenses.
The NRC staff has prepared this EA to comply with its National
Environmental Policy Act (NEPA) responsibilities to evaluate the
environmental impacts resulting from Duke's proposed action. An EA is a
concise public document prepared by the NRC to: (1) Briefly provide
sufficient evidence and analysis for determining whether to prepare an
EIS or a FONSI; (2) aid the Commission's compliance with NEPA when no
EIS is necessary; and (3) facilitate preparation of an EIS when one is
necessary.
The NRC has completed a number of environmental reviews for
activities that can inform this action and for activities specifically
at the Catawba site. These reviews were published as environmental
statements (ESs), EISs, or EAs, which were considered during the
preparation of this assessment. In particular, in 1983, the NRC issued
the final ES (FES) related to the operation of Catawba, NUREG-0921
(Reference 18). In 2002, the NRC issued a site-specific supplement to
the Generic EIS for license renewal of nuclear plants regarding
Catawba, NUREG-1437, Supplement 9 (Reference 32) (hereafter referred to
as Supplement 9). In 1999, the NRC issued a final addendum to the
Generic EIS for license renewal of nuclear plants regarding the
potential impacts of transporting spent nuclear fuel in the vicinity of
a single high-level waste repository, NUREG-1437, Addendum 1 (Reference
26). In 2001, the NRC issued the final EIS on the construction and
operation of an independent spent fuel storage installation in Utah,
NUREG-1714 (Reference 30). Finally, in 2003, the NRC issued a draft EIS
on the construction and operation of a MOX fuel fabrication facility in
South Carolina, NUREG-1767 (Reference 33).
DOE has issued a number of environmental documents that provide
useful insights to the assessment of issues involved in this proposed
action. In fulfilling its responsibility for developing and
implementing a framework for the disposition of fissile material, the
DOE has issued its final programmatic EIS (PEIS) on storage and
disposition of weapons-usable fissile materials, DOE/EIS-0229
(Reference 12). A supplemental analysis was issued by DOE in November
2003, specifically addressing the fabrication of MOX LTAs in Europe,
DOE/EIS-0229-SA3 (Reference 16), hereafter referred to as Supplement
Analysis 3. The DOE has issued its final EIS on surplus plutonium
disposition (SPD), or SPD EIS, DOE/EIS-0283 (Reference 13). A
supplemental analysis to the SPD EIS was issued by DOE in April 2003,
specifically addressing changes to the SPD program as it eliminated
some of the alternatives, DOE/EIS-0283-SA1 (Reference 15), hereafter
referred to as Supplement Analysis 1, and modified its Record of
Decision (ROD). The ROD indicated that the disposition program would
implement the National policy that was embodied in the September 2000
Agreement between the Government of the United States and the
Government of the Russian Federation Concerning Management and
Disposition of Plutonium Designated as No Longer Required for Defense
Purposes and Related Cooperation. Finally, in 2002, DOE issued the
final EIS on the geologic repository for the disposal of spent nuclear
fuel and high-level radioactive waste in Nevada, DOE/EIS-0250
(Reference 14).
This EA focuses on whether the proposed action could result in a
significant environmental impact different from the ones considered by
the NRC staff in earlier environmental reviews. The assessment
considers whether changes have occurred in the human environment in the
Catawba vicinity since the NRC staff previously considered
environmental issues there. In a number of issue areas, the NRC
references work that was documented in other publicly available
environmental documents, for example, the EISs referenced above. In
Supplement 9, the NRC staff evaluated the environmental impacts
expected to result from continued operation and maintenance of the two
Catawba facilities for an additional 20 years beyond the original
license period. The Catawba plant operations for the proposed action
would be conducted within the current license time frame; the NRC
environmental reviews for this time frame were considered in the NRC
FES and Supplement 9.
2.0 Background
2.1 The Plant and Its Environs
Catawba is located on 158 ha (391 acres) in York County, South
Carolina, approximately 29 km (18 mi) southwest of Charlotte, North
Carolina. Rock Hill, South Carolina, the nearest city, is about 10 km
(6 mi) south of the site. Catawba is situated on a peninsula that
protrudes into Lake Wylie, a man-made lake created by the Wylie Dam on
the Catawba River. The lake was initially impounded in 1904. Present
full pond was obtained in 1924 when an increase
[[Page 51114]]
in the dam height raised the water level and increased the size of the
lake. Duke either owns the land under the lake or the flood rights to
that land. The lake level fluctuates in accordance with hydroelectric
generation needs. Lake Wylie is a source of drinking water for several
municipalities and supports extensive recreational use by fishermen,
boaters, water skiers, and swimmers. As Lake Wylie is situated in both
North Carolina and South Carolina, both States are involved in the
protection, from a watershed perspective, of Lake Wylie's water
quality. Lake Wylie exhibits thermal and oxygen dynamics similar to
other southeastern reservoirs of comparable size, depth, flow
conditions, and trophic status. Lake Wylie supports a good warm-water
fishery.
Each reactor is a pressurized light-water reactor (LWR) with four
steam generators (SGs) producing steam that turns turbines to generate
electricity. Duke refuels each Catawba nuclear unit on an 18-to 24-
month schedule. Catawba has approximately 1200 full-time workers and
site contractors employed by Duke during normal plant operations.
During refueling periods, site employment increases by as many as 500
workers for temporary duty over a 30-to 40-day period. At the behest of
the DOE and its fissile material disposition program, Duke has
requested that NRC authorize it to use four MOX fuel LTAs for up to
three refueling cycles. The four LTAs contemplated under this action
would be used in lieu of four uranium dioxide fuel assemblies out of
193 assemblies in the reactor core. The LTAs would not require a
physical modification to the reactors or to any support structures,
laydown areas or storage facilities, nor would it result in any change
in infrastructure or in any land disturbance on the Catawba site.
Catawba consists of two reactor buildings, two turbine buildings,
two diesel generator buildings, six mechanical draft cooling towers,
one shared service building, one auxiliary building, one water
chemistry building, and one switchyard. The cooling water intake and
discharge structures and standby nuclear service water pond are shared
features. The reactors each have four reactor coolant loops, each of
which contains a SG that produces steam and turns turbines to generate
electricity. Each unit is designed to operate at core power levels up
to 3411 megawatts (thermal) (MW[t]), with a corresponding net
electrical output of approximately 1129 megawatts (electric) (MW[e]).
The nuclear steam supply system for each unit and the Unit 2 SGs were
supplied by Westinghouse Electric Corporation. The current Unit 1 SGs,
installed in 1996, were supplied by Babcock & Wilcox International.
The reactor containment is housed in a separate free-standing steel
containment structure within a reinforced concrete shield building. The
containment employs the ice condenser pressure-suppression concept, and
is designed to withstand environmental effects and the internal
pressure and temperature accompanying a postulated loss-of-coolant
accident or steam-line break. Together with its engineered safety
features, the containment structure for each unit is designed to
adequately retain fission products that may escape from the reactor
coolant system (RCS).
The Catawba reactors are licensed for fuel that is slightly
enriched uranium dioxide, up to 5 percent by weight uranium-235. The
Catawba reactor core has several different fuel designs that will
reside in the core with the MOX LTAs. They will include the
Westinghouse Robust Fuel Assembly design and the Westinghouse Next
Generation fuel design.
Catawba uses water from Lake Wylie for cooling and service water.
Lake Wylie is the seventh of 11 impoundments in the 410-km (255-mi)
Catawba-Wateree Project managed by Duke and licensed by the Federal
Energy Regulatory Commission (FERC). Lake Wylie extends 45 km (28 mi)
upstream from Wylie Dam to Mountain Island Dam. Flow through the
Catawba-Wateree Project is managed by Duke to optimize hydroelectric
generation, provide flood control, meet FERC minimum release
requirements, and maintain a constant and reliable water supply for
thermoelectric generating stations, surrounding communities, and
industry. The average daily withdrawal from Lake Wylie for the cooling
water and other service water systems is 386 million liters per day (L/
d) (102 million gallons per day [MGD]). Water from Lake Wylie is taken
in through two intake structures. The low-pressure service water (LPSW)
intake structure is located on the Beaver Dam Creek arm of Lake Wylie.
Trash racks and traveling screens are used to remove trash and debris
from this intake water. The intake structure is designed for a maximum
water velocity of 0.15 m/s (0.5 ft/s) in front of the trash racks at
the maximum design drawdown of Lake Wylie. The LPSW system supplies
water for various functions on the secondary side of the plant. The
nuclear service water (NSW) intake structure also is located in the
Beaver Dam Creek arm. This intake supplies cooling water to various
heat loads in the primary side of the plant and supplies water to the
standby NSW pond. Catawba does not use cooling ponds for normal
operations; however, it does have a standby NSW pond. The purpose of
this pond is to provide an ultimate heat sink in the event of a rapid
decline in water level in Lake Wylie. The pond is isolated from the
plant service water during normal plant operations. The average daily
discharge back into Lake Wylie from Catawba is 230 million L/d (60.7
MGD). The consumptive water losses result from evaporation and drift
from the six mechanical-draft cooling towers that provide cooling for
the condenser circulating water system.
The discharge structure is located on the Big Allison Creek arm of
Lake Wylie. This structure is designed to allow warm discharge water to
float on the surface with a minimum amount of mixing. Approximately
1.48 million L/d (0.39 MGD) from the conventional waste water treatment
system and from the sewage treatment system is discharged to Lake
Wylie. Catawba obtains potable water from the city of Rock Hill, South
Carolina. In addition, there are a total of three groundwater supply
wells at the Catawba site. These wells supply water on a periodic basis
to remote locations and for seasonal irrigation. The average annual
groundwater withdrawal rate from these wells is 1.89 L/s (30 gallons
per minute [gpm]).
Catawba uses liquid, gaseous, and solid radioactive waste
management systems to collect and process the liquid, gaseous, and
solid wastes that are the by-products of operations. These systems
process radioactive liquid, gaseous, and solid effluents before they
are released to the environment. The waste gas and solid waste systems
are common to both units. Portions of the liquid radioactive waste
system are shared. The waste disposal systems for Catawba meet the
design objectives of 10 CFR Part 50, Appendix I (Numerical Guide for
Design Objectives and Limiting Conditions for Operation to Meet the
Criterion ``As Low as is Reasonably Achievable'' for Radioactive
Material in Light-Water-Cooled Nuclear Power Reactor Effluents). These
systems control the processing, disposal, and release of radioactive
liquid, gaseous, and solid wastes. Radioactive material in the reactor
coolant is the source of gaseous, liquid, and solid radioactive wastes
in LWRs. Radioactive fission products build up within the fuel as a
consequence of the fission process. These fission products mostly are
contained in the sealed fuel rods, but small quantities escape and
contaminate the reactor coolant. Neutron activation
[[Page 51115]]
of the primary coolant system also is responsible for coolant
contamination.
Nonfuel solid waste results from treating and separating
radionuclides from gases and liquids and from removing contaminated
material from various reactor areas. Solid wastes also consist of
reactor components, equipment, and tools removed from service, as well
as contaminated protective clothing, paper, rags, and other trash
generated from plant design modifications and operations and routine
maintenance activities. Solid waste may be shipped to a waste processor
for volume reduction before disposal at a licensed burial site
(Reference 3). Spent resins and filters are stored or packaged for
shipment to a licensed offsite processing or disposal facility.
Routine maintenance performed on plant systems and components is
necessary for safe and reliable operation. Maintenance activities
conducted at Catawba include inspection, testing, and surveillance to
maintain the current licensing basis of the plant and to ensure
compliance with environmental and safety requirements. Certain
activities can be performed while the reactor is operating, but others
require that the plant be shut down. Long-term outages are scheduled
for refueling and for certain types of repairs or maintenance, such as
replacement of a major component. Fuel rods that have exhausted a
certain percentage of their fuel and are removed from the reactor core
for disposal are called spent fuel. Duke refuels each of the Catawba
units every 18 to 24 months (Reference 3). Each outage is typically
scheduled to last approximately 30 to 40 days, and the outage schedules
are staggered so that both units are not shut down at the same time.
Typically, one-third of the core is replaced at each refueling.
Catawba has five 230-kV transmission lines leaving the site from
the switch yard (References 3 and 18). The five lines are contained
within rights-of-way ranging from 35 to 46 m (115 to 150 ft) in width
and from 1 to 40 km (0.7 to 24.4 mi) in length covering a total of 75.7
km (42.4 mi) and approximately 295 ha (730 ac) (References 3 and 18).
The rights-of-way extend out from Catawba to the north, south, and
west. The lines and rights-of-way were constructed or rebuilt between
1973 and 1983. Duke owns less than 10 percent of the rights-of-way and
has easements for the remaining 90 percent. Vegetation in the rights-
of-way is managed through a combination of mechanical and herbicide
treatments (Reference 3). Initial treatments include mowing and/or
treatment with Arsenal (imazapyr) and Accord (glyphosate). Spot
treatments then are applied once every 3 years using Arsenal, Accord,
Garlon4A, and Krenite. Herbicide treatments in wetlands are limited to
Arsenal and Accord, which are approved for use in wetlands. In
addition, Duke cooperates with the South Carolina Department of Natural
Resources regarding protection of rare species and partners with The
Wildlife Federation on vegetation management in some portions of the
rights-of-way.
2.2 Supporting DOE Analyses
DOE has issued a number of environmental documents that provide
useful insights to the assessment of issues involved in this proposed
action. In fulfilling its responsibility for developing and
implementing a framework for the disposition of fissile material, DOE
has issued its final PEIS on storage and disposition of weapons-usable
fissile materials, DOE/EIS-0229 (Reference 12). A supplemental analysis
to the PEIS was issued by DOE in November 2003, specifically addressing
the fabrication of MOX LTAs in Europe, DOE/EIS-0229-SA3 (Reference 16),
hereafter referred to as Supplement Analysis 3. The DOE has issued its
final EIS on SPD, or SPD EIS, DOE/EIS-0283 (Reference 13). A
supplemental analysis to the SPD EIS was issued by DOE in April 2003,
specifically addressing changes to the SPD program as it eliminated
some of the alternatives, Supplement Analysis 1. Finally, in 2002, DOE
issued the final EIS on the geologic repository for the disposal of
spent nuclear fuel and high-level radioactive waste in Nevada, DOE/EIS-
0250 (Reference 14).
As background, in the following, the NRC staff summarizes the DOE
analyses regarding transportation risk of the LTAs to Catawba. The
transportation and associated impacts of the MOX LTAs to Catawba are
not related to the proposed action; the complete analysis is included
in Supplement Analysis 3. The LTAs would be shipped by truck from one
of three marine military ports near the Atlantic Ocean: Charleston
Naval Weapons Station (South Carolina), Yorktown Naval Weapons Station
(Virginia) or Naval Station Norfolk (Virginia). The ultimate selection
of the porting facility will be made by DOE and would influence the
transportation risk because transportation routing and distance, the
accident statistics for the states through which the route passes, and
the population distribution along transportation corridors would be
different, depending on which port is selected. The LTAs would be
shipped from the selected marine port by truck.
If the proposed action is approved, then, once the LTAs are
inserted into the reactor and are irradiated, the DOE proposes to take
possession of a small portion of the irradiated fuel and to conduct
post-irradiation examination and testing at one of its National
laboratories. The irradiated LTAs that remain at Catawba are expected
to be managed in a manner similar to other spent fuel and are expected
to be shipped to a high-level waste repository for ultimate
disposition; because LTAs will be used in lieu of other fuel
assemblies, the total number of spent fuel rods that have to be managed
by Duke at Catawba would be reduced by the small number that will
return to the DOE under this campaign. As part of this action to assess
the impacts of transporting the spent fuel rods to a high-level waste
repository, the NRC staff will assume that DOE will not remove any of
the spent fuel rods from the LTAs, but will ship complete fuel
assemblies to a permanent geologic repository.
3.0 Need for and Description of Proposed Action
Duke proposes three exemptions (for the use of M5TM
cladding instead of zircaloy; for fuel in the form of mixed uranium and
plutonium oxide, rather than uranium oxide; and from physical security
requirements usually required at fabrication facilities for the
protection of strategic quantities of special nuclear material) and a
license amendment to the TSs in Appendix A of the Catawba operating
licenses. The need for these changes is that they will permit the
insertion of four LTAs containing mixed uranium dioxide
(UO2) and plutonium dioxide (PuO2), also referred
to as MOX, fuel into one of the Catawba reactor cores and thus support
the U.S. Department of Energy (DOE) program for the disposition of
fissile material. It is important to note that the action is not
``batch,'' or routine widescale use of MOX fuel at Catawba or any other
reactor. The irradiation of four MOX LTAs is part of DOE's program for
fissile material disposition.
The physical design and material composition of each LTA is
identical (within manufacturing tolerances); the physical design is
based on the Framatome Advanced Mark BW design. The fuel assembly upper
and lower nozzles are 304L stainless steel. The lower nozzle has a
debris filter which is A-286 steel alloy. The grid straps located
axially along the fuel assembly are either Inconel 718 or
M5TM zirconium alloy. The hold down springs
[[Page 51116]]
on the fuel assembly top nozzle are Inconel 718. The fuel rod cladding
is M5TM zirconium alloy as well as the rod upper and lower
end caps. The fuel rod is filled with helium gas and contains a plenum
spring manufactured from either 302 or 304 stainless steel.
With the exception of the M5TM cladding, the materials
used in the fuel assembly structural components are typical of those
currently or previously in use at Catawba. The M5TM alloy is
a proprietary zirconium based alloy, composed primarily of zirconium
and niobium, that has demonstrated superior corrosion resistance and
reduced irradiation growth relative to both standard and low tin
zircaloy. Although Catawba has not previously used the M5TM
alloy, the alloy has been used in at least four other pressurized-water
reactors (PWRs).
The fuel pellet contains a mixture of UO2 and
PuO2, thus, the term MOX. The fuel is manufactured through a
sintering process like that used for the current fuel which consists of
only UO2. The current fuel is referred to as low-enriched
uranium (LEU) fuel. The fuel proposed in this application is referred
to as MOX fuel and has only been used in a limited number of
applications in PWRs in the U.S. However, reactors located in Europe
have more than 35 years of experience with MOX fuel. As of 1998, three
European fabrication plants have produced more than 435,000 MOX fuel
rods, which have been used in 35 different PWRs. The plutonium for use
in the Catawba fuel will be obtained from highly-enriched material
blended down to a fissile content useful for reactor operations. By
contrast, the European MOX fuel is recycled from commercial operating
reactor fuel. The source of the fuel feedstock determines its grade;
Catawba fuel has been referred to as ``weapons grade'' and the European
fuel as ``reactor grade.'' The Catawba fuel will be chemically polished
to meet specifications for reactor operations and, therefore, ``grade''
does not have a bearing on the presence of impurities.
During manufacturing, the composition of the LEU fuel is
approximately 3 percent to 5 percent of the U-235 isotope with the
balance of the uranium almost completely consisting of the U-238
isotope. During reactor operations a substantial portion of the uranium
in LEU fuel is converted into plutonium. The conversion of uranium to
plutonium in LWR fuel, whether LEU or MOX, is a function of burnup. An
LEU fuel assembly begins its life with an inventory of U-238 and U-235
and ends its life with an inventory that includes Pu isotopes, the
remaining U-235 and U-238, and other fission products. A MOX fuel
assembly begins its life with an inventory of uranium and Pu isotopes;
it ends its life with the remaining uranium and Pu isotopes and other
fission products. At a burnup of 50 MWd/MT (megawatt-days/metric ton),
a fuel assembly fabricated with MOX is estimated to contain
approximately 13 kg of plutonium, whereas an LEU assembly with the same
burnup would contain approximately 6 kg of plutonium. Therefore, even
with just the current LEU fuel in Catawba, and in all operating LWRs of
this design, plutonium already exists in substantial quantities.
No other primary or secondary plant structures, systems or
components are affected by this application. None of the plant
structures, systems or components, including waste systems, will be
modified and none of these systems will be operated in a different
manner or with different operating limits because of the proposed
action. The proposed use of the MOX assemblies does not represent the
introduction of any new sources of compounds, materials or elements
beyond the new clad alloy or the MOX fuel. In addition, Duke is not
requesting any changes to the TSs on coolant system specific activity
or the radioactive effluent controls program nor is it planning any
changes to the detailed radioactive effluent controls in the selected
licensee commitments in Chapter 16 of the updated final safety
evaluation report (UFSAR).
4.0 Non-Radiological Environmental Impacts of the Proposed Action
The NRC staff has completed a number of environmental reviews for
activities specifically at the Catawba site. These reviews were
published as ESs, EISs, or EAs. These reviews were considered during
the completion of this assessment and provide a current baseline of
non-radiological and radiological environmental analyses that serve as
a platform to consider whether, and if so, how the human environment
can be affected by the proposed action. In particular, in 1983, the NRC
issued the final EIS related to the operation of Catawba, NUREG-0921
(Reference 18). In 2002, the NRC issued the final supplement to the
Generic EIS for license renewal of nuclear plants, regarding Catawba,
NUREG-1437, Supplement 9. In this assessment, the NRC staff has focused
its attention on whether the proposed irradiation of four MOX LTAs has
the potential to change how an environmental resource may be affected
and whether the environmental impacts of the proposed action are
bounded by the environmental impacts previously evaluated in the final
EIS and Supplement 9.
4.1 Surface and Groundwater Use
Catawba uses water from Lake Wylie, an impoundment on the Catawba
River for the source of main condenser cooling and service water at
Catawba. There are three groundwater supply wells on the Catawba site
that are used on a periodic basis to supply remote locations and for
seasonal irrigation. The proposed action is not expected to change the
manner in which the facility is operated nor does it increase surface
or groundwater usage from that previously considered by the NRC staff
in the final EIS (Reference 18) and Supplement 9. Therefore, the NRC
staff concludes that the environmental impacts of the proposed use of
MOX LTAs are bounded by the environmental impacts previously evaluated
in the final EIS and Supplement 9.
4.2 Water Quality
Pursuant to the Federal Water Pollution Control Act of 1977 (the
Clean Water Act), the South Carolina Department of Health and
Environmental Control (SCDHEC) regulates the impacts of non-
radiological effluents discharged from Catawba via a National Pollutant
Discharge Elimination System (NPDES) permit. Adherence by the licensee
to the provisions of the permit maintains water quality standards in
Lake Wylie and in the vicinity that could potentially be affected by
operation of Catawba. The current NPDES wastewater permit for Catawba,
issued on April 30, 2001, expires on June 30, 2005.
The proposed action is not expected to change the types,
characteristics, or quantities of non-radiological effluents discharged
to the environment. There will be no change in the use or discharge of
biocides or other chemicals at Catawba as a result of the proposed
action. As discussed above, this application is for the use of four MOX
fuel LTAs to be irradiated in the reactor core. Aside from the LTAs
isolated in the reactor core, the proposed action will not introduce
any materials or chemicals into the plant that could affect the
characteristics or types of non-radiological effluents. In addition,
the method of operation of non-radiological waste systems will not be
affected by the proposed change. There are no known mechanisms
associated with a change in fuel isotopic content that would alter the
non-radiological effluent quantity. None of the parameters
[[Page 51117]]
regulated under the Clean Water Act will be changed by the proposed
action. The proposed action is not expected to change the manner in
which the facility is operated nor does it alter water quality from
that previously considered by the NRC staff in the final EIS (Reference
18) and Supplement 9. Therefore, the NRC staff concludes that the
environmental impacts of the proposed use of MOX LTAs are bounded by
the environmental impacts previously evaluated in the final EIS and
Supplement 9.
4.3 Thermal Effluents
The proposed action will not change the licensed power level for
Catawba. There will be no increase in the amount of heat that is
produced by the facility and subsequently discharged via cooling tower
blowdown to Lake Wylie. Therefore, there will be no change to the
discharge temperature and no increase in the impact of thermal
effluents on aquatic biota. The proposed action is not expected to
change the manner in which the facility is operated nor does it alter
thermal effluents that may affect aquatic biota from that previously
considered by the NRC staff in the final EIS (Reference 18) and
Supplement 9. Therefore, the NRC staff concludes that the environmental
impacts of the proposed use of MOX LTAs are bounded by the
environmental impacts previously evaluated in the final EIS and
Supplement 9.
4.4 Impingement and Entrainment
The proposed action does not involve an increase in the licensed
thermal power level for Catawba that would require additional cooling.
Because there will be no increase in the volume of water drawn into the
plant, there will be no incremental impact on aquatic biota associated
with the withdrawal of cooling water from Lake Wylie. The proposed
action is not expected to change the manner in which the facility is
operated nor does it alter impingement of adult or juvenile fish or on
the entrainment of fish eggs and larvae from that previously considered
by the NRC staff in the final EIS (Reference 18) and Supplement 9.
Therefore, the NRC staff concludes that the environmental impacts of
the proposed use of MOX LTAs are bounded by the environmental impacts
previously evaluated in the final EIS and Supplement 9.
4.5 Air Quality
Transmission lines have been associated with the production of
minute amounts of ozone and oxides of nitrogen as a result of corona
discharges from the breakdown of air near high-voltage conductors.
Through the years, line designs have been developed that greatly reduce
corona effects. The transmission lines associated with the Catawba
facility meet the 1997 version of National Electric Safety Code and
corona effects are minimal on those lines.
SCDHEC has issued a Clean Air Act air emissions and operating
permit to Catawba for the release of controlled amounts of effluents to
the atmosphere resulting from operation of the emergency diesel
generators (EDGs) and other equipment on the site. The Charlotte, North
Carolina, metropolitan area has not been identified as a non-attainment
or maintenance area, therefore, no assessment of the vehicle exhaust
emissions anticipated at the time of peak workforce is required by the
Clean Air Act. The proposed use of the MOX LTAs will not result in an
increase in station electrical output or a change in the operation of
the station EDGs or other equipment.
The proposed action is not expected to change the manner in which
the facility is operated nor does it alter air quality, either as a
result of release of increased amounts of effluents to the atmosphere
or as a result of corona associated with the transmission lines for
Catawba, from that previously considered by the NRC staff in the final
EIS (Reference 18) and Supplement 9. Therefore, the NRC staff concludes
that the environmental impacts of the proposed use of MOX LTAs are
bounded by the environmental impacts previously evaluated in the final
EIS and Supplement 9.
4.6 Noise
The proposed action will not result in any increase in ambient
noise level either on-site or beyond the site boundary. When noise
levels are below the levels that result in hearing loss, impacts have
been judged primarily in terms of adverse public reactions to the
noise. As noted in the Generic EIS for License Renewal, NUREG-1437
(Reference 24), no nuclear plants have offsite noise levels sufficient
to cause hearing loss. Generally, power plant sites do not result in
offsite levels more than 10 dB(A) above background. Noise level
increases more than 10 dB(A) would be expected to lead to interference
with outdoor speech communication, particularly in rural areas or low-
population areas, such as Catawba, where the background noise level is
in the range of 45-55 dB(A). Generally, noise surveys around major
sources of noise such as large highways and airports have found that,
when the background noise level increases beyond 60-65 dB(A), noise
complaints increase significantly. Noise levels below 60-65 dB(A) are
generally considered to be of small significance. The principal sources
of noise at Catawba are the result of operation of mechanical draft
cooling towers, transformers, and loudspeakers. These noise sources are
not perceived by large numbers of people offsite. In addition, these
sources of noise are sufficiently distant from critical receptors
outside the plant boundaries that the noise is attenuated to nearly
ambient levels and is scarcely noticeable.
The proposed action is not expected to change the manner in which
the facility is operated nor does it alter ambient noise level onsite
or beyond the site boundary at Catawba from that previously considered
by the NRC staff in the final EIS (Reference 18) and Supplement 9.
Therefore, the NRC staff concludes that the environmental impacts of
the proposed use of MOX LTAs are bounded by the environmental impacts
previously evaluated in the final EIS and Supplement 9.
4.7 Thermophilic Organisms
Thermophilic organisms are known to inhabit cooling tower basins
and natural bodies of water in the southern latitudes of the U.S.,
including water bodies in the vicinity of Catawba. Waste heat from
power plant facilities could stimulate the growth of these organisms,
some of which are known to be potentially harmful to man.
The use of MOX LTAs will not change the licensed power level at
Catawba. There will be no increase in the amount of heat that is
produced by the facility and subsequently discharged via cooling tower
blowdown to Lake Wylie that would change the discharge temperature or
that would increase the impact of thermal discharges on thermophilic
organisms. The proposed action is not expected to change the manner in
which the facility is operated nor would it alter the abundance of
pathogenic thermophilic microbiological organisms due to heated
discharges from Catawba from that previously considered by the NRC
staff in the final EIS (Reference 18) and Supplement 9. Therefore, the
NRC staff concludes that the environmental impacts of the proposed use
of MOX LTAs are bounded by the environmental impacts previously
evaluated in the final EIS and Supplement 9.
4.8 Aquatic Ecology
Recently, in Supplement 9, the NRC staff evaluated and disclosed
the impacts resulting from the current mode of operation and that are
expected to
[[Page 51118]]
occur during the extended term of the renewed operating licenses at
Catawba. The NRC staff has considered the potential impacts of the
proposed action on water use and quality, impingement and entrainment,
thermal effluents, and thermophilic organisms. The proposed action is
not expected to change the manner in which the facility is operated nor
does it alter any resource components associated with aquatic ecology
at Catawba from that previously considered by the NRC staff in the
final EIS (Reference 18) and Supplement 9. Therefore, the NRC staff
concludes that the environmental impacts of the proposed use of MOX
LTAs are bounded by the environmental impacts previously evaluated in
the final EIS and Supplement 9.
4.9 Terrestrial Ecology
Recently, in Supplement 9, the NRC staff evaluated and disclosed
the impacts resulting from the current mode of operation and that are
expected to occur during the extended term of the renewed operating
licenses at Catawba. The NRC staff has considered the potential impacts
of the proposed action on cooling tower operation, transmission line
operation and maintenance, and on-site or off-site land use. The
proposed action is not expected to change the manner in which the
facility is operated nor does it alter any resource components
associated with terrestrial ecology at Catawba from that previously
considered by the NRC staff in the final EIS (Reference 18) and
Supplement 9. Therefore, the NRC staff concludes that the environmental
impacts of the proposed use of MOX LTAs are bounded by the
environmental impacts previously evaluated in the final EIS and
Supplement 9.
4.10 Threatened or Endangered Species
On the basis if its conclusions of no impact on aquatic or
terrestrial resources as discussed above, the NRC staff concludes that
the proposed use of four MOX fuel LTAs at Catawba will have no effect
on any Federally-listed threatened or endangered species or their
designated critical habitat.
4.11 Socioeconomic Impacts
The licensee plans to implement additional security measures to
support activities associated with the proposed action, from the time
the material (MOX) arrives on site until it is irradiated. Duke has not
identified the need to hire additional staff to support the proposed
action. Catawba already has over 1200 full-time workers employed by
Duke and site contractors during normal plant operations. During
refueling periods, site employment increases by as many as 500 workers
for temporary duty over a 30-to 40-day period. Even if a limited number
of additional security personnel were hired to implement the proposed
action, it will not significantly increase the number of licensee staff
or contractors employed at the facility; therefore, there would be no
noticeable impact on housing or transportation that might result from
an increase in workforce. Likewise, there will be no need for
additional public services, such as for public safety, public
utilities, social services, or education. Finally, no impacts are
expected on tourism and recreation or taxes as a result of the proposed
action. The proposed action is not expected to change the manner in
which the facility is operated nor does it alter any resource
components associated with socioeconomics in the Catawba vicinity from
that previously considered by the NRC staff in the final EIS (Reference
18) and Supplement 9. Therefore, the NRC staff concludes that the
environmental impacts of the proposed use of MOX LTAs are bounded by
the environmental impacts previously evaluated in the final EIS and
Supplement 9.
4.12 Offsite Land Use
The land occupied by Catawba is in unincorporated York County. York
County and its municipalities currently have land use plans and zoning
requirements that govern development activities within the county. Duke
has not identified the need to hire additional staff to support the
proposed action. Catawba already has over 1200 full-time workers
employed by Duke and site contractors during normal plant operations.
During refueling periods, site employment increases by as many as 500
workers for temporary duty over a 30- to 40-day period. Even if a
limited number of additional personnel were hired to implement the
proposed action, it will not significantly increase the number of
licensee staff or contractors employed at the facility. The proposed
action will not have any impact on the local infrastructure, such as
transportation or housing in the Catawba vicinity that might result
from an increased workforce. Because there will not be any need to
augment the local infrastructure, the proposed change will not be
accompanied by any land-disturbing activities offsite. The proposed
action is not expected to change the manner in which the facility is
operated nor does it alter any resource components associated with land
use in the Catawba vicinity from that previously considered by the NRC
staff in the final EIS (Reference 18) and Supplement 9. Therefore, the
NRC staff concludes that the environmental impacts of the proposed use
of MOX LTAs are bounded by the environmental impacts previously
evaluated in the final EIS and Supplement 9.
4.13 Cultural Resources and Historic Properties
The proposed action will not result in any changes in off-site land
use or in any land-disturbing activities. There will be no physical
changes to the existing facility or disturbances to undeveloped
portions of the site. The NRC staff concludes that the use of MOX lead
test assemblies at Catawba will not have environmental impacts on
cultural resources and historic properties. The proposed action is not
expected to change the manner in which the facility is operated nor
does it alter any resource components associated with cultural
resources and historic properties in the Catawba vicinity from that
previously considered by the NRC staff in the final EIS (Reference 18)
and Supplement 9. Therefore, the NRC staff concludes that the
environmental impacts of the proposed use of MOX LTAs are bounded by
the environmental impacts previously evaluated in the final EIS and
Supplement 9.
4.14 Aesthetics
As noted above, the proposed action will not require any physical
changes to the existing facility or be accompanied by any land-
disturbing activities, either off-site or on-site. Also, the proposed
change will not result in any changes in land use plans or zoning
requirements in unincorporated York County or its municipalities. The
proposed action is not expected to change the manner in which the
facility is operated nor does it alter any resource components
associated with aesthetics or viewsheds in the Catawba vicinity from
that previously considered by the NRC staff in the final EIS (Reference
18) and Supplement 9. Therefore, the NRC staff concludes that the
environmental impacts of the proposed use of MOX LTAs are bounded by
the environmental impacts previously evaluated in the final EIS and
Supplement 9.
4.15 Summary
In summary, the proposed irradiation of four MOX LTAs at Catawba
would not result in a significant change in non-radiological impacts in
the areas of surface or groundwater use, chemical or thermal
discharges, intake effects, air quality, noise, thermophilic organisms,
aquatic or terrestrial ecology, threatened
[[Page 51119]]
or endangered species, socioeconomics, off-site land use, cultural
resources or historic properties, aesthetics, or environmental justice.
No other non-radiological impacts were identified or would be expected.
Therefore, based on the above discussions, the NRC staff concludes that
there are no significant non-radiological environmental impacts
associated with the proposed action.
5.0 Radiological Environmental Impacts of the Proposed Action
5.1 Gaseous Effluents
The licensee has evaluated the potential impacts that could result
from the proposed use of MOX LTAs on the type or amount of gaseous
radioactive effluents that could be released from the Catawba facility.
This evaluation includes a consideration of fuel cladding performance
and fuel integrity considerations and is based on the similarity of MOX
fuel to the present LEU fuel, both from a fuel design and a fission
product inventory perspective. The analysis takes into account the
replacement of four out of 193 fuel assemblies with the assemblies
containing MOX fuel; this action considers the four MOX LTAs.
As fuel is irradiated, both activation and fission products are
created. The activation products that are created are a function of
impurities and the chemistry of the reactor coolant and the neutron
flux that the materials encounter. Thermal neutron flux is
significantly lower in MOX fuel than in LEU fuel, which would tend to
lower activation products. However, for four lead assemblies, this is
expected to be an insignificant effect.
The outer surfaces of the fuel assemblies which are exposed to the
RCS are the same materials which have been used at Catawba for many
years. The exception is the introduction of the M5TM alloy.
This material is a zirconium-based alloy and is more corrosion
resistant than currently-used zirconium-based alloys. Therefore, the
fuel assembly surfaces exposed to reactor coolant should not interact
to produce any different quantity or type of radioactive material in
the RCS.
The performance of M5TM cladding is expected to meet or
exceed that of the current zircaloy cladding. Therefore, there is not
expected to be any increase in the quantity of failed fuel rods. In the
event of failed fuel rods, the MOX fuel could release fission products
from the gap into the RCS. However, the chemical volume and control
system and radioactive waste systems are designed to cope with fuel rod
failures. The same fission products present from the failure of a LEU
fuel rod would be present for the failure of a MOX fuel rod. Only
slight differences in curie content of respective isotopes would be
expected in the event of a cladding failure.
Fission product inventories and fuel gap inventories are of the
same order of magnitude in both MOX fuel and LEU fuels. In particular,
the amount of iodine and noble gas that would be released into the
reactor coolant in the event of a leaking fuel rod would be similar.
Additionally, any liquid or gaseous effluents would be processed by the
plant liquid waste and waste gas systems prior to release to the
environment. These waste treatment systems would limit radioactive
discharges to the environment as a result of hold-up for decay,
filtering, and demineralization. The plant treatment systems are
capable of treating these radioactive effluents because the types of
radioactive material in MOX and LEU fuel are the same and the curie
content of MOX fuel is of the same order of magnitude as LEU fuel.
Thus, the licensee is expected to maintain the same level of
radioactive control and to remain within the same regulatory limits
with the MOX fuel as for the LEU fuel.
Therefore, based on the materials and performance capabilities of
the fuel and plant systems, there is no basis to expect any change in
gaseous effluent characteristics typical of normal plant operations. In
addition, Duke has not requested any changes to the TSs limits on RCS
specific activity or to the radioactive effluent controls program and
is not planning any changes to the selected licensee commitments of
Chapter 16 of the UFSAR. These requirements and commitments place
limits on various isotopes and specify requirements for monitoring and
surveillance, thereby limiting the release of gaseous radioactive
effluents from the Catawba facility.
The NRC staff concludes that there will be no anticipated changes
in the type or amount of gaseous radiological effluents resulting from
the use of MOX fuel lead assemblies compared to the current LEU fuel.
The licensee will continue to maintain its radioactive gaseous
effluents within license conditions and regulatory limits. Therefore,
there will be no additional environmental impacts as a result of
gaseous radioactive effluents from the proposed action.
5.2 Liquid Effluents
Duke has evaluated the potential impacts that could result from the
proposed use of MOX lead assemblies on the type or amount of liquid
radioactive effluents that could be released from the Catawba facility.
This evaluation includes a consideration of fuel cladding performance
and fuel integrity considerations and is based on the similarity of MOX
fuel to the present LEU fuel, both from a fuel design and a fission
product inventory perspective. The analysis takes into account the
replacement of four out of 193 fuel assemblies with fuel assemblies
containing MOX fuel.
As fuel is irradiated, both activation and fission products are
created. The activation products that are created are a function of
impurities and the chemistry of the reactor coolant and the neutron
flux that the materials encounter. Impurities in the reactor coolant
and reactor coolant water chemistry are independent of the fuel type,
whether MOX or LEU. Thermal neutron flux is significantly lower in MOX
fuel than in LEU fuel, which would tend to lower activation products.
However, for four lead assemblies, this is expected to be an
insignificant effect.
There are no expected changes to liquid radioactive effluents as a
result of the proposed action. As discussed above, with the exception
of the M5TM alloy cladding on the MOX fuel rods in the LTAs,
the outer surfaces of the fuel assemblies which are exposed to the RCS
and several other components are very similar to the materials that
have been used at Catawba for many years. The M5TM alloy
material is a zirconium-based alloy and is more corrosion resistant
than currently used zirconium-based alloys. Therefore, the fuel
assembly surfaces exposed to reactor coolant should not interact to
produce any different quantity or type of radioactive material in the
RCS.
The cladding performance of M5TM is expected to meet or
exceed that of the current zircaloy cladding, therefore, there is not
expected to be any increase in the quantity of failed fuel rods. In the
event of failed fuel rods the MOX fuel could release fission products
from the gap into the RCS. However, the chemical volume and control
system and radioactive waste systems are designed to cope with fuel rod
failures. The same fission products present from the failure of a LEU
fuel rod would be present for the failure of a MOX fuel rod. Only
slight differences in curie content of respective isotopes are
expected.
Therefore, based on the materials and performance capabilities of
the fuel and plant systems there is no basis to expect any change in
liquid effluent characteristics typical of normal plant
[[Page 51120]]
operations. In addition, Duke is not requesting any changes to the TSs
on RCS specific reactivity or the radioactive effluent controls
program, nor is it planning any changes to the detailed radioactive
effluent controls in the selected licensee commitments section of
Chapter 16 of the UFSAR. These requirements and commitments place
limits on the concentration of radioactive material released in liquid
effluents and specify requirements for monitoring and surveillance,
thereby limiting the release of liquid radioactive effluents from the
Catawba facility. Therefore, there will be no additional environmental
impacts as a result of liquid radioactive effluents from the proposed
action.
5.3 Waste Management and Solid Radioactive Waste
The introduction of the four LTAs should have minimal impact on
solid waste. As discussed above, there is no change to radioactive
liquid effluents and no need for liquid effluent cleanup that would
generate additional solid radioactive waste in the form of resins or
evaporator bottoms. There would be no expected impact on primary system
filters or resins associated with normal plant operations.
The quantity of waste associated with a pool side post-irradiation
examination program which will be conducted for the MOX fuel assemblies
is minimal and consistent with other post-irradiation examinations
performed during refueling outages. This waste would be small volumes
of low-level waste such as disposable portions of anti-contamination
clothing.
The proposed action would not result in an increase in authorized
power level, therefore, there will be no increase in the amount of
water required to remove heat from the reactor. This means that there
will be no need for additional water treatment in the secondary system
that could lead to an increase in the amount of spent resins and
evaporator bottoms.
The proposed action would not increase the number of fuel rods
irradiated in the reactor. Four assemblies containing MOX fuel will
replace four LEU assemblies in the reactor core. No additional fuel
assemblies will be irradiated. Therefore, this will not result in an
increase in the volume of solid radioactive waste from fittings,
endcaps, and springs for fuel assemblies.
The spent fuel storage racks will not be changed; therefore there
will be no change in the volume of irradiated/contaminated material
that will need to be disposed of in an off-site burial facility.
Therefore, based on the discussion above, the NRC staff concludes
that the proposed action will have no impact on waste management and
solid radioactive waste.
5.4 Occupational Dose
The licensee estimates that there will be slight increases in the
radiation exposure of its workforce during the handling of MOX fuel
during receipt and handling operations. The increase in dose is due to
a higher dose rate from a fresh MOX fuel assembly as compared to a
fresh LEU fuel assembly. The total neutron and gamma dose rate at 10
centimeters from the face of a fresh MOX fuel assembly averages about 6
mrem/hour, falling off to about 1.8 mrem/hour at 100 centimeters
(Reference 5). This is a relatively low radiation field; however, it is
larger than that associated with a LEU fuel assembly, which has
virtually no radiation field at these distances.
The initial fuel receipt, handling, and inspection activities for
the fresh MOX fuel LTAs could result in a conservatively estimated
total occupational dose in the range of 0.020 to 0.042 person-rem
(Reference 5). However, the licensee will use the application of the As
Low As Reasonably Achievable principles to try to effect lower doses
than are estimated. Radiation doses of this magnitude are well within
regulatory occupational exposure limits and do not represent an impact
to worker health. There are no other expected changes in normal
occupational operating doses as a result of the proposed action.
Not included among the workforce on the Catawba site are the
workers who will conduct hot-cell examinations of the irradiated MOX
fuel after it has been taken from the Catawba reactor core and shipped
to Oak Ridge National Laboratory (ORNL). In order to assess the impact
of the proposed action on the workers at ORNL, the NRC staff has
referenced DOE's SPD EIS to provide an assessment of the occupational
doses resulting from post-irradiation examinations following
irradiation of the LTAs. DOE has estimated the radiological
consequences for the hot-cell examination of fuel assemblies at ORNL.
There are an estimated 10 workers associated with the hot-cell
examination work, each estimated to accumulate approximately .177
person-rem (Reference 9). The hot-cell post-irradiation examinations at
ORNL will be conducted in accordance with DOE radiation protection
programs and procedures Occupational doses in the range of 0.020 to
0.042 total person-rem as a result of poolside examination and 0.177
person-rem for each of the 10 workers performing hot-cell examinations
at ORNL would be far below the regulatory limit for individual workers
of 5 rem/year. Therefore, the NRC staff concludes that there will be no
significant increase in occupational dose as a result of the proposed
use of MOX LTAs at Catawba.
5.5 Dose to the Public
Dose to the public will not be changed by the use of four lead
assemblies at Catawba during normal operations. As discussed above,
there is no basis to contemplate an increased source of liquid, gaseous
or solid radiological effluents that could contribute to increased
public exposure during normal operations. The SPD EIS states that no
change would be expected in the radiation dose to the general public
from normal operations associated with disposition of MOX fuel at the
proposed reactors (Reference 13). In addition, DOE has performed an
analysis that demonstrates no incremental change in doses for 16 years
of reactor operation.
For members of the public, the licensee estimates that there will
be no detectable increase in public dose during normal operations with
the MOX fuel assemblies (Reference 5). Use of the lead assemblies in
the reactor core will not change the characteristics of plant effluents
or water use. During normal plant operation, the type of fuel material
will have no effect on the chemistry parameters or radioactivity in the
plant water systems. The fuel material is sealed inside fuel rods that
are seal-welded and leaktight. Therefore, there would be no direct
impact on plant radioactive effluents and the associated radiation
exposure.
5.6 Design-Basis Accident Consequences
The models used by Duke to assess design-basis accident (DBA)
consequences reflect conservative assumptions to ensure that there is
an adequate safety margin. In particular, the NRC staff notes that Duke
assumed that plutonium concentration of the pins in the LTAs was 5
percent. The nominal LTA fuel design calls for 176 fuel pins with a
plutonium concentration of 4.94 percent; 76 pins at 3.35 percent, and
12 pins at 2.40 percent. The nominal average plutonium concentration is
4.37 percent. Conservatively basing the calculation on 5 percent
plutonium concentration provides margin to compensate for differences
(e.g., manufacturing tolerances and power
[[Page 51121]]
history differences) between the nominal design and the actual fuel as
loaded in the core.
The differences in the initial fuel isotopics between MOX and LEU
fuel are potentially significant to accident radiological consequences
because the distribution of fission products created depends on the
particular fissile material. If the fissile material is different, it
follows that the distribution of fission products may be different. For
example, one atom of I-131 is created in 2.86 percent of all U-235
fissions, whereas one atom of I-131 is created in 3.86 percent of all
Pu-239 fissions. This shift in fission product distribution was
assessed for its influence on postulated radiological consequences of
DBAs.
Duke's application provided an accident source term for irradiated
MOX fuel. The NRC staff compared that source term to data prepared by
Sandia National Laboratory and performed independent calculations of
core inventory using the ORIGEN-S code (as described in NUREG/CR-0200
(Reference 28). The NRC staff has determined that source term
assumptions used by Duke in its analyses of the accident consequences
of the use of the MOX LTAs are adequate and conservative for assessing
the consequences of DBAs.
To address the impact of MOX fuel on gap fractions, Duke assumed an
increase of 50 percent over that provided in Regulatory Guide 1.183
(Reference 23), for LEU fuel for each of the MOX LTAs. Duke provided
information to support this assumption with comparative data from
European MOX facilities. The NRC staff obtained the assistance of
Pacific Northwest National Laboratory to confirm the adequacy of Duke's
assumed increase in the gap fractions. Based upon its review, the NRC
staff determined that the gap fraction increase assumed by Duke in its
analyses is acceptable.
Duke has evaluated the radiological consequences of postulated DBAs
involving MOX LTAs. Duke has categorized various DBAs on the basis of
how many fuel assemblies would be affected by that event. Duke
identified two major categories:
Fuel-handling accidents (FHA) involving damage to a few
fuel assemblies. These include fresh and irradiated FHAs (involving the
drop of a single fuel assembly) and the weir gate drop (WGD) accident
(causing damage to seven fuel assemblies). A small number of assemblies
are involved such that if the four MOX LTAs were in the damaged
population, they would comprise all or a significant portion of the
damaged population. As such, these events are limiting with regard to
the potential increase in dose that would result if they occurred while
the MOX LTAs were in the core. [The loss of coolant accident (LOCA)
discussed below is limiting with regard to the magnitude of the dose.]
At-power accidents involving fuel damage to a significant
portion of the entire core. These accidents range from the locked rotor
accident with 11 percent core damage (21 assemblies damaged), to the
rod ejection accident with 50 percent core damage (97 fuel assemblies
damaged), to the large break loss-of-coolant accident (LOCA) with full
core damage (all 193 fuel assemblies damaged). In this case, the
relative effect of damaging all four MOX LTA is reduced as the fuel
damage population increases. For example, in a DBA LOCA, all 193 fuel
assemblies are postulated to be damaged and the four MOX LTAs
constitute just 2 percent of all the fuel assemblies in the core.
The NRC staff considered the following additional category to
further assess potential DBA consequences:
Accident source term assumptions derived from RCS
radionuclide concentrations, such as SG tube rupture, main steam line
break, instrument line break, waste gas decay tank rupture, and liquid
storage tank rupture (LST). Estimates of the radionuclide releases
resulting from these events are based on pre-established administrative
controls that are monitored by periodic surveillance requirements, for
example: RCS and secondary plant-specific activity LCO, or offsite dose
calculation manual effluent controls. Increases in specific activities
due to MOX, if any, would be limited by these administrative controls.
Because the analyses were based upon the numerical values of these
controls, there is no impact on the previously analyzed DBAs in this
category and no further discussion of these events is warranted.
The analysis of public doses for the Exclusion Area Boundary (EAB)
and Low-Population Zone (LPZ) resulting from the two classes of
accidents considered by Duke are discussed below. In addition, the NRC
staff has evaluated the radiological consequences of affected DBAs on
the operators in the control room.
5.6.1 Fuel-Handling Accidents
Duke has performed analyses of the dose consequences of FHAs,
including: the drop of a single fresh fuel assembly; the drop of a
single irradiated MOX fuel assembly during refueling; and a weir drop
accident, which leads to damage of seven irradiated fuel assemblies
including the four MOX fuel assemblies.
Fresh MOX LTA Drop
This accident analysis is not currently part of the Catawba
licensing basis. Duke performed this analysis to assess the
radiological consequences of a drop of a fresh MOX LTA prior to it
being placed in the spent fuel pool (SFP). Duke stated that plutonium
isotopes have a much higher specific activity than uranium isotopes
and, if inhaled, could present a more severe radiological hazard.
Although the configuration of the MOX pellets and LTA fuel rods
provides protection against inhalation hazards, some plutonium could
become airborne if the MOX LTA is damaged.
Duke performed an analysis to estimate the radiological
consequences from a fresh MOX fuel drop accident. The approach for this
analysis was consistent with the assumptions and methodologies that
were used in the calculations supporting the MOX Fuel Fabrication
Facility (MFFF) construction authorization request. The MOX MFFF
application and review did not address the MOX fuel drop accident and
although the guidance of NUREG/CR-6410 has not been used previously for
DBA analyses for power reactors, the NRC staff concludes that the
overall methodology used in the MFFF review is appropriate for the
present application.
The dose estimated by the licensee for the postulated drop of a
single fresh MOX fuel assembly was 0.3 rem total effective dose
equivalent (TEDE) at the EAB, which is a small fraction of the 10 CFR
50.67 dose criterion (i.e., 25 rem TEDE at the EAB) and is, therefore,
found to be acceptable. The NRC staff has evaluated the analysis
provided by the licensee and concludes that the methodology and
calculations have been applied in a conservative manner. Therefore, the
NRC staff concludes that there will be no significant adverse
environmental impact as a result of a fresh MOX fuel drop accident.
Irradiated MOX LTA Drop
Duke has calculated that the radiological consequences resulting
from a FHA involving the drop of a single irradiated MOX fuel assembly
would be 2.3 rem TEDE at the EAB, 0.34 rem TEDE at the edge of the LPZ,
and 2.1 rem TEDE in the control room--increases of about 64 percent
over the previous analysis for LEU fuel.
The NRC staff performed confirmatory analyses of the spent FHA
using the MOX LTA source term that it generated using the SCALE SAS2H
computer code (as described in NUREG/CR-0200, (Reference 28)). For the
irradiated FHA, the source term reflected the decay of
[[Page 51122]]
the radionuclides for a 72-hour period after shutdown of the reactor
prior to moving fuel and, conservatively, was increased (multiplied) by
a radial peaking factor of 1.65. The results of the NRC staff's
analyses confirmed the results obtained by Duke. The doses estimated by
the licensee for the postulated spent FHA are a small fraction of the
10 CFR 50.67 dose criterion and are, therefore, acceptable and will not
result in a significant adverse environmental impact.
Weir Gate Drop
Duke has calculated the radiological consequences resulting from a
FHA involving the drop of a weir gate, which is assumed to damage 7
fuel assemblies, including all four MOX fuel assemblies. The calculated
doses would be 3.5 rem TEDE at the EAB, 0.5 rem TEDE at the edge of the
LPZ, and 3.3 rem TEDE in the control room. These dose estimates
represent increases of about 58 percent over the previous analysis for
LEU fuel, but are still well below the 10 CFR 50.67 dose criterion.
The NRC staff performed confirmatory analyses of the weir gate drop
accident using the MOX LTA source term that it generated using the
SCALE SAS2H computer code. For this accident, the source term for the
four MOX assemblies and the three LEU assemblies reflected the decay of
the radionuclides for 19.5 days after shutdown of the reactor prior to
moving fuel and, conservatively, was increased (multiplied) by a radial
peaking factor of 1.65 (Reference 36). The results of the NRC staff's
analyses confirmed the results obtained by Duke. The doses estimated by
the licensee for the postulated accident were below the 5 rem TEDE
criterion specified in 10 CFR 50.67 and are, therefore, acceptable and
will not have a significant adverse environmental impact.
5.6.2 At-Power Accidents
The current licensing basis analyses assume that all fuel
assemblies (193) are affected by a LOCA. For the locked-rotor accident,
11 percent of the core (21 assemblies) is assumed to be affected; for
the rod-ejection accident, 50 percent of the core (97 assemblies) is
assumed to be affected. For these events, Duke assumes that the four
MOX LTAs are in the affected fuel population displacing four LEU
assemblies. Because the dose is directly proportional to the fuel
assembly inventory and gap fractions, the impact on the previously
analyzed accident doses is based on quantifying the change in fission
product release due to replacing up to four LEU fuel assemblies with
the MOX LTAs. Although the consequences of these accidents could be
determined by updating the current licensing basis analyses, Duke
elected to perform a comparative evaluation, which the NRC staff has
independently verified.
Duke selected the thyroid dose due to I-131 as the evaluation
benchmark because the thyroid dose is typically more limiting than the
whole body dose in that there is less margin between calculated thyroid
doses and its associated dose criterion. Also, I-131 is generally the
most significant contributor to thyroid dose due to its abundance and
long decay half-life. Duke has determined that the I-131 inventory in a
MOX LTA is 9 percent greater than that of an equivalent LEU fuel
assembly.
Loss-of-Coolant Accident
For the LOCA, the four MOX LTAs represent 2.1 percent of the 193
assemblies in the core and the potential increase in the iodine release
and the thyroid dose would be 1.32 percent. The previously-calculated
thyroid dose would increase to 90.2 rem at the EAB and to 25.3 rem at
the LPZ, which is well below the 300 rem dose criterion of 10 CFR
100.11.
Locked-Rotor Accident
For the locked-rotor accident, the four MOX LTAs represent 19
percent of the 21 assemblies in the core assumed to be involved in the
postulated accident and the potential increase in the iodine release
and the resulting thyroid dose would be 12 percent. The previously-
calculated thyroid dose would increase to 4.1 rem at the EAB and to 1.3
rem at the LPZ, which is well below the 300 rem dose criterion of 10
CFR 100.11.
Rod-Ejection Accident
For the rod-ejection accident, the four MOX LTAs represent 4.1
percent of the 97 assemblies in the core assumed to be involved in the
postulated accident and the potential increase in the iodine release
and the resulting thyroid dose would be 2.63 percent. The previously-
calculated thyroid dose would increase to 1.03 rem at the EAB and to
0.1 rem at the LPZ, which is well below the 300 rem dose criterion of
10 CFR 100.11.
5.6.3 Control Room Dose
Control room dose is the only occupational dose that has been
previously considered for DBA conditions. The at-power accident with
the most severe consequences for the control room operators is the
LOCA; the control room doses from postulated locked-rotor or rod-
ejection accidents are bounded by the calculated control room dose from
the LOCA. Duke determined that the control room thyroid dose after a
postulated LOCA that could be attributable to the irradiation of four
MOX fuel LTAs would increase by 1.32 percent to 5.37rem. This is below
the dose criterion set forth in 10 CFR Part 50, Appendix A, Criterion
19, and is not considered significant.
Duke determined that the radiological consequences to workers in
the control room following a postulated WGD accident would result in a
calculated dose to control room operators of 3.3 rem TEDE. While this
is an increase of 58 percent over the dose previously analyzed for LEU
fuel, it remains below the 5 rem TEDE criterion specified in 10 CFR
50.67. The change in calculated doses to control room operators
attributable to the use of the four MOX fuel LTAs does not represent a
significant environmental impact.
5.6.4 Conclusion
The most-limiting DBA (a LOCA) would result in a calculated off-
site dose at the EAB of 90.2 rem to the thyroid and 25.3 rem to the
thyroid at the edge of the LPZ. These doses represent increases of less
than 1.32 percent of the dose previously calculated for LEU fuel and
remain well below the limit of 300 rem thyroid specified in 10 CFR
100.11 for off-site releases. The calculated change in dose
consequences at the EAB and at the LPZ that could be attributable to
the use of the four MOX fuel LTAs is not significant.
The NRC staff concludes that the environmental impact resulting
from incremental increases in EAB, LPZ, and control room dose following
postulated DBAs that could occur as a result of the irradiation of four
MOX LTAs does not represent a significant environmental impact.
5.7 Fuel Cycle Impacts
The source of fissionable material is outside of the fuel cycle
(coming, as it does, from the pits of dismantled nuclear warheads that
are excess to the strategic stockpile). Therefore, the proposed
irradiation of four MOX LTAs at Catawba would preclude use of four LEU
assemblies. This would have only negligible impact on the fuel cycle.
5.8 Transportation of Fresh Fuel
The transportation of the unirradiated MOX fuel assemblies is the
responsibility of the DOE and has been addressed by the DOE in
Supplement Analysis 3, regarding the fabrication of MOX fuel LTAs in
Europe and their return to the U.S. In Section 5.2 of Supplement
Analysis 3, the truck
[[Page 51123]]
transportation risks from U.S. ports to Catawba, the methodology used,
and the summary results are described.
DOE indicates that LTAs will be one shipment using Safe Secure
Trailer/SafeGuards Transports (SST/SGTs); DOE stated that the shipment
would be made in SST/SGTs because unirradiated MOX fuel in large enough
quantities is subject to security concerns similar to those associated
with weapons-grade plutonium (Reference 13). The SST/SGT is a specially
designed component of an 18-wheel tractor-trailer vehicle that has
robust safety and security enhancements.
The risks and consequences associated with exposures to
transportation workers and persons residing near or sharing
transportation links with shipments of radioactive material packages
during routine transport operations or as a result of accidents were
assessed by DOE using the RADTRAN 5 computer code (Reference 29); see,
Chapter 5 of Supplement Analysis 3 (Reference 16). For incident-free
transportation risk, DOE used the RADTRAN 5 code to calculate the dose
and corresponding risk based on the external dose rate from the
shipping vehicle, the transportation route and population density along
the route. For accident transportation risk, DOE used the State-
specific accident rates between the marine ports and Catawba, and a
conditional accident frequency-severity relationship that considered
the route conditions. DOE used the accident rate for SST/SGT transport
and the accident severity category classifications of NRC's NUREG-0170
(Reference 17). DOE also calculated the non-radiological accident
risks.
The radiological risk of transporting the four fresh MOX LTAs is an
estimate of the number of latent cancer fatalities (LCFs) and is small
for both the public and the driver. Table 2 (Page 17 of Supplement
Analysis 3) indicates that for incident-free transportation of the
fresh MOX LTAs, the radiological risk to the crew which corresponds to
shipping from the Naval Station Norfolk port in Virginia, is a maximum
of 4.0 x 10-6 LCFs. DOE indicates that the maximum
radiological risk to the public for incident-free transportation is 3.2
x 10-6 LCFs, associated with shipping from Naval Station
Norfolk or Yorktown Naval Weapons Station. For accidents, in Table 2
DOE provides an estimate of the radiological risk in terms of LCFs.
Non-radiological risks are stated as expected number of accident
fatalities from non-radiological factors. The accident risk analysis
does not distinguish between the crew and the public. For postulated
accidents, the radiological risk is calculated to be a maximum of 2.1 x
10-7 LCFs, which corresponds to transporting the MOX LTAs to
Catawba from either the Naval Station Norfolk port or the Yorktown
Naval Weapons Station port. The maximum non-radiological risk is
calculated to be 1.7 x 10-4 which also corresponds to
shipping from Naval Station Norfolk or Yorktown Naval Weapons Station.
For both normal and accident conditions, no fatalities associated with
incident free or accidents during transportation are expected.
5.9 Transportation of Spent Fuel
Radiological risks during routine transportation would result from
the potential exposure of people to low levels of external radiation
near a loaded shipment, either stationary or in transit. Any irradiated
MOX fuel rods that are not shipped offsite for post irradiation
examination will be stored on-site until they are shipped to a
permanent high-level waste repository. A shipping container must have a
certificate of compliance (COC) issued by the NRC. As specified in 10
CFR Part 71 Subpart D, the applicant for a COC must submit a Safety
Analysis Report (SAR) which the NRC staff then reviews against a number
of standards. After review, the NRC staff issues a safety evaluation
report (SER) describing the basis of approval.
The only disposal site currently under consideration in the U.S. is
the proposed geologic repository in Nevada (Reference 14). For purposes
of complying with NEPA requirements, it is assumed that spent MOX LTAs
would eventually be shipped to the proposed repository in Nevada.
However, the DOE's application for a license to operate the repository
has not yet been submitted to the NRC. There is no assurance that the
DOE's application, if submitted, would be approved, but it is
reasonable to use the Nevada repository as a surrogate for this
assessment.
On a per-kilometer-traveled basis, the NRC reported that the
routine radiological and vehicle-related transportation risks for spent
MOX fuel would be similar to those estimated for fresh MOX fuel,
plutonium metal, or transuranic radioactive waste (Reference 33). The
transportation risks of LEU spent nuclear fuel and spent MOX fuel
transport, in particular, were estimated in the DOE final EIS
concerning disposal of spent nuclear fuel and high-level waste in
Nevada (Reference 14). DOE reported that under the mostly legal-weight
truck scenario, approximately 53,000 truck shipments were estimated to
result in approximately 12 LCFs to workers, 3 LCFs to the public, and 5
traffic fatalities.
The NRC has assessed the transportation impacts of a campaign of
batch MOX fuel use in conjunction with an application for the
construction and operation of a MOX fuel fabrication facility
(Reference 33); the NRC's impact evaluation from that assessment is
used to put the spent MOX LTA transportation risks into proper context.
It should be noted that the NRC has not received an application
requesting widescale or batch use of recycled plutonium for use in MOX
fuel for any commercial reactor, and the NRC has not made any
determination regarding any proposal for such use. In NUREG-1767
(Reference 33), the NRC estimated the transportation risks of the spent
MOX fuel based on average shipment risks calculated from the DOE
results (Reference 14); the estimates show that no fatalities would be
expected. Shipment of all of the spent MOX fuel generated under a batch
use scenario would result in approximately 598 shipments (Reference
33). Further, assuming three assemblies per cask, the campaign might be
expected to result in approximately 0.1 worker LCFs, 0.03 public LCFs,
and 0.05 transportation fatalities. Under this proposed action, only
four MOX LTAs are contemplated. Even if the number of shipments were
minimized to ship the highest concentration of MOX spent fuel, i.e.,
all four assemblies in two casks, and, using the results of the
aforementioned assessment, the MOX LTAs might be expected to result in
a small fraction (i.e., 2 / 598) of the quantified risk estimates,
above, and not discernible from earlier NRC analyses involving solely
LEU spent fuel.
DOE proposes to take possession of a small portion of the
irradiated fuel (i.e., spent fuel) from Catawba and to conduct post-
irradiation examination and testing at one of its national
laboratories. DOE described these activities in the SPD EIS (Reference
13). The transportation risks for this limited amount of spent MOX fuel
that would be shipped to ORNL in Tennessee from Catawba is considered
to be bounded by the risk estimates from the spent MOX LTAs. Apart from
the smaller quantities involved for the post-irradiation examination
and testing, the total number of kilometers traveled from Catawba to
ORNL is less than that from Catawba to any contemplated repository.
In light of the above, no significant impacts would be expected
from the shipment of either the spent MOX LTAs to a repository or the
shipment of a
[[Page 51124]]
small portion of the spent MOX LTAs to ORNL. Furthermore, the estimated
risks are only a very small fraction of the radiological annual
transport risks estimated in NUREG-0170, the NRC's Final EIS on the
transportation of radioactive material (Reference 17). The NRC has
determined that the impact from normal transportation and accidents is
small.
5.10 Severe Accidents
Environmental issues associated with postulated severe accidents
are discussed in the Final Environmental Impact Statement for Catawba,
NUREG-0921 (Reference 18), the Generic Environmental Impact Statement
for License Renewal of Nuclear Plants (GEIS), NUREG-1437, Volumes 1 and
2 (Reference 24) and in Supplement 9 to NUREG-37, the site-specific
supplement. Severe nuclear accidents are those accidents that are more
severe than DBAs because they could result in substantial damage to the
reactor core, whether or not there are serious off-site consequences.
In the environmental reviews identified above, the NRC staff assessed
the impacts of severe accidents, using the results of existing analyses
and site-specific information to conservatively predict the
environmental impacts of severe accidents for Catawba.
Severe accidents initiated by external phenomena such as tornadoes,
floods, earthquakes, and fires have not traditionally been discussed in
quantitative terms in FESs and were not specifically considered for the
Catawba site in the GEIS (Reference 24). However, in the GEIS, the NRC
staff did evaluate existing impact assessments performed by NRC and by
the industry at 44 nuclear plants in the U.S. and concluded that the
risk from beyond design-basis earthquakes at existing nuclear power
plants, including Catawba, was small. [The NRC's standard for
significance was established using the Council on Environmental
Quality's terminology for ``significantly'' (40 CFR 1508.27, which
requires consideration of both ``context'' and ``intensity'').
``Small'' in this context means ``environmental effects are not
detectable or are so minor that they will neither destabilize nor
noticeably alter any important attribute of the resource.''] The NRC
staff did conclude in the GEIS that the risks from other external
events were adequately addressed by a generic consideration of
internally initiated severe accidents.
As part of its ongoing licensing reviews, the NRC staff also
reviewed Revision 2b of the Catawba Probabilistic Risk Assessment (PRA)
(Reference 4), which is a full scope Level 3 PRA. In this case, the
Catawba PRA included the analysis of internal as well as external
events. The internal events analysis was an updated version of the
Individual Plant Examination (IPE) model (Reference 1), and the
external events analysis was based on the Individual Plant Examination
for External Events (IPEEE) model (Reference 2). The calculated total
core damage frequency (CDF) for internal and external events in
Revision 2b of the Catawba PRA is 5.8 x 10-5 per year.
Internal event initiators represent about 80 percent of the total CDF
and were composed of transients (24 percent of total CDF), loss of
coolant accidents (29 percent of total CDF), internal flood (24 percent
of total CDF), and reactor pressure vessel rupture (2 percent of total
CDF). Remaining contributors together accounted for less than 3 percent
of total CDF. External event initiators represented about 20 percent of
the total CDF and are composed of seismic initiators (15 percent of
total CDF), tornado initiators (4 percent of total CDF), and fire
initiators (2 percent of the total CDF). Duke estimated the dose to the
population within 80 km (50 mi) of the Catawba site from all initiators
(internal and external) to be 0.314 person-sieverts (Sv) (31.4 person-
rem) per year (Reference 3); internal events account for approximately
0.21 person-Sv (21 person-rem). Early and late containment failures
accounted for the majority of the population dose.
In its most recent review of severe accidents for the purpose of
determining whether mitigation alternatives were warranted, the NRC
staff considered the following major elements:
The Level 1 and 2 risk models that form the basis for the
September 1992 IPE submittal (Reference 1);
The major modifications to the IPE models that have been
incorporated in Revision 2b of the PRA (Reference 4);
The external events models that form the basis for the
June 1994 IPEEE submittal (Reference 2); and
The analyses performed to translate fission product
release frequencies from the Level 2 PRA model into offsite consequence
measures (Reference 3).
The NRC staff's review of the Catawba IPE was described in an NRC
safety evaluation dated June 7, 1994 (Reference 22). In that review,
the NRC staff evaluated the methodology, models, data, and assumptions
used to estimate the CDF and characterize containment performance and
fission product releases. The NRC staff concluded that Duke's analysis
met the intent of Generic Letter (GL) 88-20 (Reference 19) and NUREG-
1560 (Reference 25), which means the IPE was of adequate quality to be
used to look for design or operational vulnerabilities. The NRC staff's
review primarily focused on the licensee's ability to examine Catawba
for severe accident vulnerabilities and not specifically on the
detailed findings or quantification estimates. Overall, the NRC staff
concluded that the Catawba IPE was of adequate quality to be used as a
tool in searching for areas with high potential for risk reduction and
to assess such risk reductions, especially when the risk models are
used in conjunction with insights, such as those from risk importance,
sensitivity, and uncertainty analyses.
The NRC staff's review of the Catawba IPEEE was described in a SER
dated April 12, 1999 (Reference 27). Duke did not identify any
fundamental weaknesses or vulnerabilities to severe accident risk with
regard to the external events. In the SER, the NRC staff concluded that
the IPEEE met the intent of Supplement 4 to GL 88-20 (Reference 21),
and that the licensee's IPEEE process was capable of identifying the
most likely severe accidents and severe accident vulnerabilities.
The NRC staff reviewed the process used by Duke to extend the
containment performance (Level 2) portion of the IPE to the off-site
consequence (Level 3) assessment. This included consideration of the
source terms used to characterize fission product releases for each
containment release category and the major input assumptions used in
the off-site consequence analyses. The NRC staff reviewed Duke's source
term estimates for the major release categories and found these
predictions to be in reasonable agreement with estimates of NUREG-1150
(Reference 20) for the closest corresponding release scenarios. In
Supplement 9, the NRC staff concluded that the assignment of source
terms was acceptable. The differences in the source terms for a severe
accident involving substantial damage to the core solely with LEU fuel
assemblies or substituting four LEU assemblies with MOX LTAs are
indistinguishable, given the uncertainty, and would result in no
appreciable change in the risk estimates.
The plant-specific evaluation included the Catawba reactor core
radionuclide inventory, emergency response evacuation modeling based on
Catawba evacuation time estimate studies, release category source terms
from the Catawba PRA, Revision 2b, analysis (same as the source terms
used in the IPE), site-specific meteorological data for a
representative year, and projected population distribution within
[[Page 51125]]
a 80 km (50 mi) radius (Reference 4). The NRC staff confirmed that Duke
used appropriate values for the consequence analysis and reported the
results of its risk evaluation for Catawba in Supplement 9. The NRC
staff concluded that the methodology used by Duke to estimate the CDF
and offsite consequences for Catawba was adequate.
In the license renewal GEIS (Reference 24), the NRC staff concluded
that the probability-weighted consequences from atmospheric releases
associated with severe accidents was judged to be of small significance
for all plants, including Catawba. The NRC staff concluded that, for
both the drinking water and aquatic food pathways, the probability-
weighted consequences from fallout due to severe accidents is of small
significance for all plants, including Catawba. The NRC staff concluded
that the probability-weighted consequences from groundwater releases
associated with severe accidents was judged to be of small significance
for all plants, including Catawba.
Nothing about the proposed action would significantly change either
the probability or consequences of severe accidents. The small
percentage of non-LEU fuel assemblies that could be involved in a
severe accident would not result in an appreciable change in the risk
estimates. The proposed action is not expected to change the manner in
which the facility is operated nor does it alter Catawba's risk profile
for severe accidents analyzed in the GEIS for license renewal
(Reference 24) and, more recently, its assessment of mitigation
alternatives in Supplement 9. Therefore, the NRC staff concludes that
the environmental impacts of the proposed use of MOX LTAs are bounded
by the environmental impacts previously evaluated in the GEIS and
Supplement 9.
5.11 Decommissioning
Once a nuclear power generating facility permanently ceases
commercial operation, the licensee is required to begin
decommissioning. Decommissioning is the process of removing a facility
or site safely from service and reducing residual radioactivity to a
level that permits either the release of the property for unrestricted
use and termination of the license or release of the property under
restricted conditions and termination of the license. In November 2002,
the NRC staff issued Final Supplement 1 to NUREG-0586, entitled
``Generic EIS on Decommissioning of Nuclear Facilities,'' (Reference
31) regarding the decommissioning of power reactors. Supplement 1 to
the GEIS for decommissioning comprehensively evaluated all
environmental impacts related to the radiological decommissioning of
nuclear power facilities. By rule, if a licensee anticipates the need
to perform activities that have not been previously considered or
activities with impacts greater than those considered in the
decommissioning GEIS, then it must obtain NRC approval with a license
amendment request. At this time, Duke has not identified and the NRC
staff is unaware of any activities that are dissimilar from those
assessed in NUREG-0586 that might occur as a result of the LTA
campaign. Therefore, the NRC staff has determined that the impacts
associated with the decommissioning of a facility that would irradiate
four MOX LTAs would be bounded by the impacts predicted by Supplement 1
to NUREG-0586 (Reference 31).
Decommissioning impacts are primarily related to the activities
associated with the decontamination and dismantlement of the
structures, systems, and components of the facility. The use of the MOX
fuel LTAs will not change the scope or impact of those activities.
During decommissioning, the primary system is typically decontaminated
using a chemical flush. Contamination in the primary system is removed
by the chemical flush and deposited in ion exchange resins that are
permanently disposed in licensed burial facilities. Decommissioning of
the facility would not result in the generation of any significant
increase in liquid or solid radioactive waste. No increases in offsite
or occupational exposure would be expected. No significant quantities
of contaminated or activated additional structural material would be
generated during decommissioning because of the use of the lead
assemblies.
Therefore, the NRC staff concludes that the decommissioning of the
facility after use of the lead assemblies would not result in impacts
that are significantly different from a facility undergoing
decommissioning that did not use the lead assemblies. Furthermore, the
impacts of decommissioning the Catawba facility after the irradiation
of four MOX fuel LTAs are bounded by the impacts evaluated in NUREG-
0586, Supplement 1 (Reference 31).
5.12 Summary
The proposed irradiation of four MOX fuel LTAs at Catawba would not
significantly increase the probability or consequences of accidents,
would not introduce any new radiological release pathways, would not
result in a significant increase in occupational or public radiation
exposure, and would not result in significant additional fuel cycle
environmental impacts. Accordingly, the Commission concludes that there
are no significant environmental radiological impacts associated with
the proposed action.
6.0 Irreversible or Irretrievable Commitment of Resources
The NRC staff has considered the commitment of resources related to
operation of Catawba. These resources include materials and equipment
required for plant maintenance and operation, the nuclear fuel used by
the reactors, and ultimately, permanent offsite storage space for the
spent fuel assemblies. As described in Supplement 9, the most
significant resource commitments related to operation of the Catawba
facility are the fuel and the permanent storage space. The resource
commitments to be considered in this assessment are associated with the
proposed irradiation of four MOX fuel LTAs in the reactor core of one
of the Catawba facilities. Aside from the plutonium in the MOX fuel
(20.2 kg Pu per assembly), all of the materials that are to be used
would be used if the action were not to proceed.
7.0 Unavoidable Adverse Impacts
The NRC staff has considered whether the proposed action would
cause significant unavoidable adverse impacts and concludes that the
proposed irradiation of four MOX fuel LTAs will have no environmental
non-radiological impacts and only minor radiological impacts.
Therefore, the NRC staff concludes that there will be no significant
adverse impacts as a result of the proposed action.
8.0 Mitigation
The NRC staff has evaluated the impacts that would accrue from the
proposed action. The NRC staff has concluded that there will be no
environmental non-radiological impacts and only minor radiological
impacts. Therefore, the NRC staff concludes that mitigation is not
warranted or necessary to minimize the impacts of this action.
9.0 Cumulative Impacts
The NRC staff considered potential cumulative impacts during its
evaluation of the proposed action. For the purposes of this analysis,
past actions were those related to the resources at the site at the
time of the plant licensing and construction;
[[Page 51126]]
present actions are those related to the resources at the site at the
time of current operations of the power plant; and future actions are
considered to be those that are reasonably foreseeable through the end
of plant operation. The impacts of the proposed action are combined
with other past, present, and reasonably foreseeable future actions at
Catawba regardless of what agency (Federal or non-Federal) or person
undertakes such other actions. These combined impacts are defined as
``cumulative'' in 40 CFR 1508.7 and include individually minor, but
collectively significant, actions taking place over a period of time.
The NRC staff concludes that the proposed action would add only minute,
incremental effects to those already accruing from current operation at
Catawba using LEU fuel.
10.0 Alternatives to the Proposed Action
The NRC staff has evaluated a number of reasonable alternatives to
the proposed action, including the no-action alternative. Two of the
alternatives involve use of the reactors at two other Duke facilities,
McGuire and Oconee Nuclear Station. A fourth alternative involves a
different scheme than is currently proposed for transporting all of the
rods from the irradiated MOX fuel LTAs offsite for post-irradiation
examination (PIE) at ORNL.
10.1 No-Action Alternative
The NRC staff has considered the no-action alternative. If the four
MOX fuel LTAs are not irradiated in one of the Catawba reactors, four
LEU fuel assemblies with comparable performance characteristics will be
used. The impacts resulting from the proposed action and the no-action
alternative are similar.
10.2 Use of the McGuire Nuclear Station, Units 1 and 2 as an
Alternative
MOX fuel lead assembly irradiation at a McGuire unit is a
technically feasible alternative to using MOX LTA fuel at Catawba.
McGuire and Catawba share the same fuel assembly design, and the RCS
operating parameters are similar among all four units. All of the
reactors are base loaded, with approximately 18 month intervals between
refueling. All four reactors have the same rated thermal power--3411
MW(t) nominal. In addition, transportation modes and means of delivery
to the two plants are the same.
Due to these and other similarities, there is a de minimis
difference in the environmental impacts of MOX fuel lead assembly use
at McGuire as compared to MOX fuel lead assembly use at Catawba. The ER
on MOX fuel lead assembly use submitted to the NRC in support of the
license amendment request (Reference 5), is applicable to both plants.
Duke's responses to NRC requests for additional information (Reference
7 and Reference 9) related to environmental consequences would be
technically applicable to irradiation of the MOX LTAs at McGuire as
well as at Catawba.
In a letter dated September 23, 2003, Duke amended its license
amendment request to apply to Catawba only (Reference 6). This action
was based on refueling schedule considerations and the desire to
minimize the resource requirements associated with MOX fuel lead
assembly licensing. While use of MOX fuel lead assemblies at McGuire
remains technically feasible, these refueling schedule and resource
considerations make Catawba preferable for use of the MOX fuel lead
assemblies in the late spring of 2005. That date, in turn, is driven by
lead assembly fabrication and transportation (Reference 10).
10.3 Use of Oconee Nuclear Station, Units 1, 2, and 3 as an Alternative
MOX fuel lead assembly irradiation at Oconee is not considered to
be a technically feasible alternative to using MOX fuel lead assemblies
at a Catawba unit. As described in Duke's license amendment request,
the reason for the lead assembly program is to demonstrate the
acceptable performance of MOX fuel derived from weapons grade plutonium
in reactors. McGuire and Catawba are very similar in design to European
reactors that have amassed decades of experience using reactor grade
MOX fuel. Further, McGuire and Catawba are the facilities that have
been proposed to and accepted by the DOE for the larger-scale
irradiation of the MOX fuel. It should be noted that the NRC has not
received an application for wide scale routine, or batch, use of MOX
fuel in any reactor and the NRC has not made any determination
regarding any proposal for wide scale routine, or batch, use.
McGuire and Catawba share the same fuel assembly design. By
contrast, Oconee has a different fuel assembly design and a different
RCS design than the McGuire and Catawba plants. Oconee fuel assemblies
have a 15x15 lattice; McGuire and Catawba use 17x17 fuel. The fuel rod
pitch is 0.568 inches at Oconee, versus 0.496 inches at McGuire and
Catawba. Oconee has 177 fuel assemblies in each core; McGuire and
Catawba have 193 fuel assemblies in each core. Oconee uses a fixed
incore detector system with rhodium detectors to measure neutron flux;
McGuire and Catawba use a movable incore detector system with fission
chambers. Oconee is a Babcock and Wilcox-designed reactor; McGuire and
Catawba are four-loop Westinghouse plants. The core thermal power level
is 2568 MW(t) at Oconee, vs. 3411 MW(t) at McGuire and Catawba. RCS
average temperature is 579 [deg]F at Oconee, vs. 586 [deg]F at McGuire
and Catawba.
Duke considers that a lead assembly program with the prototypical
fuel design under prototypical conditions is required prior to
contemplating use of significant quantities of MOX fuel at McGuire or
Catawba. The differences between McGuire/Catawba and Oconee, while not
extreme, are great enough such that MOX fuel lead assembly use at
Oconee would not be considered prototypical (Reference 10). For those
same reasons, Duke considers it likely that NRC would not consider a
MOX fuel lead assembly program at Oconee to be sufficient for NRC to
authorize Duke to use significant quantities of MOX fuel at McGuire or
Catawba. Therefore, Oconee is not a practical alternative for a MOX
fuel lead assembly program.
Duke has stated that it knows of no technical reason that MOX fuel
could not be used safely at Oconee (Reference 10). However, in the
context of the ongoing U.S. program to dispose of surplus plutonium
using MOX fuel, McGuire and Catawba are the only reactors selected for
the program and the only technically feasible alternatives under Duke's
control for a MOX fuel lead assembly program.
10.4 Offsite Storage of All MOX LTA Fuel Rods
As part of the MOX Fuel Project lead assembly program, a small
number of irradiated MOX fuel rods will, at the direction of DOE, be
transported to ORNL for post-irradiation examination (PIE). The fuel
rods would be destructively examined at ORNL and eventually disposed of
as waste. The remainder of the MOX fuel rods (approximately 1000 rods)
would remain in the SFP at Catawba until they are accepted by DOE
pursuant to the Nuclear Waste Policy Act, presumably to a permanent
geologic repository.
Transportation of irradiated MOX fuel to an interim offsite
location is beyond the scope of the Duke lead assembly license
amendment application (Reference 10). Duke's application is
specifically limited to the receipt and storage of MOX fuel as well as
incore irradiation of the MOX fuel. The environmental impacts of
irradiated
[[Page 51127]]
MOX fuel transportation and disposal have been addressed in other EISs.
There are no specific plans in place to transport offsite all of the
MOX fuel rods from the MOX fuel lead assemblies in conjunction with the
offsite shipment of a limited number of rods to ORNL for PIE.
Nevertheless, the NRC staff requested that Duke consider an
alternative involving a variation of the proposed DOE transportation of
the irradiated MOX fuel rods in the LTAs (Reference 35). Duke could
ship all of the MOX fuel assemblies to ORNL for storage even though
there are no facilities for such storage at ORNL (Reference 10).
Nevertheless, in this hypothetical case, following interim storage,
ORNL could ship the four MOX fuel assemblies to another storage
location. The difference in these approaches is minor from an
environmental perspective. The alternative approach would eliminate the
need for the direct shipment of four fuel assemblies from Catawba to
Yucca Mountain, should Yucca Mountain eventually be licensed, however,
offsetting this benefit is the shipment from Catawba to ORNL and from
ORNL to Yucca Mountain and additional handling. Duke has stated that it
expects that the difference between the alternatives would be
negligible (Reference 10).
It should be noted that it is necessary to cool spent fuel
assemblies in the SFP prior to shipping them offsite. Therefore, the
alternative of shipping all of the fuel offsite would by necessity
involve some period of onsite storage at Catawba. There is no
conceivable alternative (other than no-action) that involves no spent
MOX fuel assembly storage at Catawba (Reference 10).
If DOE were to transport all of the rods in the four MOX LTAs
offsite, no irradiated MOX fuel would need to be stored on the Catawba
site. The NRC staff concludes that the environmental impacts from this
alternative would be similar to those for the proposed action.
11.0 Agencies and Persons Consulted
On July 30, 2004, the NRC staff consulted with the South Carolina
State official, Mr. Mike Gandy of the Department of Health and
Environmental Controls, regarding the environmental impact of the
proposed action. The State official had no comments.
12.0 References
1. Duke letter to NRC, Catawba Individual Plant Examination
(IPE) Submittal, September 10, 1992.
2. Duke letter to NRC, Individual Plant Examination of External
Events (IPEEE) Submittal, Catawba Nuclear Station, June 21, 1994.
3. Duke letter to NRC, Applicant's Environmental Report--
Operating License Renewal Stage Catawba Nuclear Station Units 1 and
2, June 12, 2001, ADAMS ML011660138.
4. Duke, Probabilistic Risk Assessment Revision 2b, Catawba
Nuclear Station, April 18, 2001.
5. Duke letter to NRC, Proposed Amendments to the Facility
Operating License and Technical Specifications to Allow Insertion of
Mixed Oxide (MOX) Fuel Lead Assemblies and Request for Exemption
from Certain Regulations in 10 CFR Part 50, February 27, 2003, ADAMS
ML030760734.
6. Duke letter to NRC, Catawba and McGuire, Mixed Oxide Fuel
Lead Assembly License Amendment Request, September 23, 2003, ADAMS
ML032750033.
7. Duke letter to NRC, Catawba, Response to Request for
Additional Information Regarding the Use of Mixed Oxide Lead Fuel
Assemblies, November 3, 2003, ADAMS ML033210369.
8. Duke letter to NRC, Response to Request for Additional
Information dated November 30, 2003, Regarding the Use of Mixed
Oxide Lead Fuel Assemblies, December 10, 2003, ADAMS ML033510563.
9. Duke letter to NRC, Catawba, Response to Request for
Additional Information, Mixed Oxide Fuel Assemblies (Environmental,
Radiological, and Materials), February 2, 2004, ADAMS ML040510064.
10. Duke letter to NRC, Catawba, Response to Request for
Additional Information Mixed Oxide Fuel Lead Assemblies
(Environmental), March 1, 2004, ADAMS ML040710492.
11. Duke letter to NRC, Catawba, Amended Information Regarding
Radiological Consequences for MOX Fuel Lead Assemblies, March 16,
2004, ADAMS ML040840483.
12. U.S. Department of Energy (DOE), DOE/EIS-0229, Storage and
Disposition of Weapons-Usable Fissile Materials Final Programmatic
Environmental Impact Statement, December 1996.
13. DOE/EIS-0283, Surplus Plutonium Disposition Environmental
Impact Statement, 1 through 5, November 1999.
14. DOE/EIS-0250, Final Environmental Impact Statement for a
Geologic Repository for the Disposal of Spent Nuclear Fuel and High-
Level Radioactive Waste at Yucca Mountain, Nye County, Nevada,
February 2002.
15. DOE/EIS-0283-SA1, Supplemental Analysis and Amended Record
of Decision--Changes Needed to the Surplus Plutonium Disposition
Program, April 2003.
16. DOE/EIS-0229-SA3, Supplemental Analysis--Fabrication of
Mixed Oxide Fuel Lead Assemblies in Europe, November 2003.
17. NRC NUREG-0170, Final Environmental Impact Statement on the
Transportation of Radioactive Material by Air and Other Means,
December 1977.
18. NRC NUREG-0921, Final Environmental Impact Statement Related
to the Operation of Catawba Nuclear Station, Units 1 and 2, January
1983.
19. NRC Generic Letter 88-20, Individual Plant Examination for
Severe Accident Vulnerabilities, November 23, 1988.
20. NRC NUREG-1150, Severe Accident Risks--An Assessment for
Five U.S. Nuclear Power Plants, December 1990.
21. NRC Supplement 4 to Generic Letter 88-20, Individual Plant
Examination of External Events (IPEEE) for Severe Accident
Vulnerabilities,'' June 28, 1991.
22. NRC Letter to Duke, Safety Evaluation of Catawba Nuclear
Station, Units 1 and 2, Individual Plant Examination (IPE)
Submittal, June 7, 1994.
23. NRC Regulatory Guide 1.183, ``Alternative Radiological
Source Terms for Evaluating Design Basis Accidents at Nuclear Power
Reactors.''
24. NRC NUREG-1437, Volumes 1 and 2, Generic Environmental
Impact Statement for License Renewal of Nuclear Plants, May 1996.
25. NRC NUREG-1560, Individual Plant Examination Program:
Perspectives on Reactor Safety and Plant Performance, December 1997.
26. NRC NUREG-1437, Vol. 1, Addendum 1, Final Report--Generic
Environmental Impact Statement--License Renewal of Nuclear Plants--
Main Report--Section 6.3--Transportation Table 9.1, Summary of
Findings on NEPA issues for license renewal of nuclear power plants,
August 1999.
27. NRC Letter Duke, Catawba--Review of Individual Plant
Examination of External Events (IPEEE), April 12, 1999.
28. NRC NUREG/CR-0200, Revision 6, Volume 1, SAS2H: A Coupled
One-Dimensional Depletion and Shielding Analysis Module, March 2000.
29. Sandia National Laboratories, SAND 2000-1256, RADTRAN 5
Technical Manual, May 2000.
30. NRC NUREG-1714, Vol. 1, Final Environmental Impact Statement
for the Construction and Operation of an Independent Spent Fuel
Storage Installation on the Reservation of the Skull Valley Band of
Goshute Indians and the Related Transportation Facility in Toole
County, Utah, December 2001.
31. NRC NUREG-0586, Generic Environmental Impact Statement on
Decommissioning of Nuclear Facilities, November 2002.
32. NRC NUREG-1437, Supplement 9 (Catawba) to the Generic
Environmental Impact Statement for License Renewal of Nuclear
Plants, December 2002.
33. NRC NUREG-1767, Draft Report for Comment--Environmental
Impact Statement on the Construction and Operation of a Mixed Oxide
Fuel Fabrication Facility at the Savannah River Site, South
Carolina, February 2003.
34. NRC Letter to Duke, Catawba--Request for Additional
information Regarding Mixed Oxide Lead Fuel Assemblies, December 16,
2003, ADAMS ML033500408.
35. NRC Letter to Duke, Catawba--Request for Additional
Information Regarding Mixed Oxide Lead Fuel Assemblies, February 20,
2004, ADAMS ML040490683.
36. NRC Letter to Duke, transmitting safety evaluation for
proposed amendments to the operating license, April 5, 2004, ADAMS
ML040970046.
[[Page 51128]]
13.0 Finding of No Significant Impact
On the basis of the EA, the NRC concludes that the proposed action
will not have a significant effect on the quality of the human
environment. Accordingly, the NRC has determined not to prepare an EIS
for the proposed action.
For further details with respect to the proposed action, see the
licensee's letter dated February 27, 2003, as supplemented by letters
dated September 15, September 23, October 1 (two letters), October 3
(two letters), November 3 and 4, December 10, 2003, and February 2 (two
letters), March 1 (three letters), March 9 (two letters), March 16 (two
letters), March 26, March 31, April 13, April 16, May 13, and June 17,
2004. Documents may be examined, and/or copied for a fee, at the NRC's
Public Document Room (PDR), located at One White Flint North, Public
File Area O1 F21, 11555 Rockville Pike (first floor), Rockville,
Maryland. Publicly available records will be accessible electronically
from the Agencywide Documents Access and Management System (ADAMS)
Public Electronic Reading Room on the Internet at the NRC Web site,
http://www.nrc.gov/reading-rm/adams.html. Persons who do not have
access to ADAMS or who encounter problems in accessing the documents
located in ADAMS, should contact the NRC PDR Reference staff by
telephone at 1-800-397-4209 or 301-415-4737, or by e-mail to
[email protected].
Dated at Rockville, Maryland, this 10th day of August 2004.
For the Nuclear Regulatory Commission.
Edwin M. Hackett,
Project Director, Project Directorate II, Division of Licensing Project
Management, Office of Nuclear Reactor Regulation.
[FR Doc. 04-18731 Filed 8-16-04; 8:45 am]
BILLING CODE 7590-01-P