[Federal Register Volume 62, Number 72 (Tuesday, April 15, 1997)]
[Notices]
[Pages 18371-18373]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9661]
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
[Docket No. 50-390]
Tennessee Valley Authority; Watts Bar Nuclear Plant, Unit 1;
Environmental Assessment and Finding of No Significant Impact
The U.S. Nuclear Regulatory Commission (the Commission) is
considering issuance of an amendment to Facility Operating License No.
NPF-90, issued to Tennessee Valley Authority, (the licensee), for
operation of the Watts Bar Nuclear Plant, Unit 1, located in Rhea
County, Tennessee.
Environmental Assessment
Identification of the Proposed Action
The current spent fuel pool storage capacity at the Watts Bar
Nuclear Plant (WBN) is 1312 fuel assembly storage locations of which
484 are usable. The Tennessee Valley Authority (TVA) requested an
amendment to the WBN Unit 1 operating license that would increase the
storage capacity of the spent fuel pool to 1835 assemblies. The
proposal consists of replacing the existing racks with spent fuel
storage racks that were designed, manufactured, and used until 1995 in
the Sequoyah Nuclear Plant, increasing the maximum initial enrichment
of fuel to 5.0 weight percent (wt%) U-235, changing the spacing of
stored fuel assemblies; adding limiting condition for operation (LCO)
requirements for the combination of initial enrichment and burnup in an
acceptable burnup domain, and requiring the boron concentration to be
greater than or equal to 2000 parts per million (ppm) during fuel
movement. The submittal also proposed surveillance requirements to
verify the initial enrichment and burnup and require chemical analysis
to verify boron concentration. The proposed action is in accordance
with the licensee's application for amendment dated October 23, 1996,
as supplemented by letters dated December 11, 1996, January 31,
February 10 and 24, and March 11 and , 1997.
The Need for the Proposed Action
WBN is in its first operating cycle; therefore, the spent fuel pool
is dry and no fuel assemblies are stored in it. Under current
conditions, the spent fuel pool capacity will support three to four
cycles of operation before losing the capacity for a full core offload
(193 fuel assemblies). However, taking into account loading new fuel
into the pool and component shuffling during an outage, the ability to
accept a discharge of one full core off-load could be impacted as early
as the year 2000. There are no commercial independent spent fuel
storage facilities operating in the U.S., nor are there any domestic
reprocessing facilities; therefore, the projected loss of storage
capacity in the WBN pool would affect TVA's ability to operate WBN. The
proposed amendment is needed to ensure the capability of full core
offload is available for some time in the future.
Alternatives to the Proposed Action
The licensee considered several wet and dry storage alternatives to
the proposed action. The following wet storage alternatives were
considered by the licensee: reracking with new ultra high density
racks, rod consolidation, and transshipment (pool-to-pool). The
following dry storage alternatives were considered by the licensee:
metal casks, concrete casks, concrete vaults, and multi-purpose
canisters/overpacks. The licensee considered several factors when
evaluating the options: effects on plant systems and operations;
impacts on safety, including fuel handling; radiation exposure;
industry experience; subsequent actions for further increasing onsite
spent fuel storage capacity; flexibility for ultimate disposal of spent
fuel; and overall costs. Based on these considerations, the licensee
determined that reuse of the Sequoyah Nuclear Plant storage racks was
the most viable option.
In 1975, the staff prepared a Generic Environmental Impact
Statement (GEIS) on spent fuel storage. The findings were documented in
NUREG-0575, ``Final Generic Environmental Impact Statement (FGEIS) on
Handling and Storage of Spent Light Water Power Reactor Fuel.'' The
storage of spent fuel, as discussed in the NUREG, is considered to be
an interim action, not a final solution to permanent disposal. The
methods of expanding spent fuel storage capacity considered in the
FGEIS identified negligible differences in the environmental impacts
and costs of the different alternatives, with the exception that
expansion of the spent fuel pool was less costly and did not involve
transportation issues. The FGEIS noted that since there are variations
in storage design and limitations caused by spent fuel already stored
in the pools, licensing reviews should be performed on a case-by-case
basis to resolve plant-specific concerns.
The staff evaluated the licensee's list of alternatives as well as
other alternatives. The following alternatives were considered by the
staff:
Shipment of Fuel to a Permanent Federal Fuel Storage/Disposal Facility
Shipment of spent fuel to a high-level radioactive storage facility
is an alternative to increasing the onsite spent fuel storage capacity.
However, the U.S. Department of Energy's (DOE's) high-level radioactive
waste repository is not expected to begin receiving spent fuel until
approximately 2010, at the earliest. In October 1996, the
Administration did
[[Page 18372]]
commit DOE to begin storing wastes at a centralized location by January
31, 1998. However, no location has been identified and an interim
federal storage facility has yet to be identified in advance of a
decision on a permanent repository. Therefore, shipping spent fuel to
the DOE repository is not considered an alternative to increased onsite
spent fuel storage capacity at this time.
Shipment of Fuel to a Reprocessing Facility
Reprocessing of spent fuel from the WBN facility is not a viable
alternative since there are no operating commercial reprocessing
facilities in the United States. Therefore, spent fuel would have to be
shipped to an overseas facility for reprocessing. However, this
approach has never been used and it would require approval by the
Department of State as well as other entities. Additionally, the cost
of spent fuel reprocessing is not offset by the salvage value of the
residual uranium; reprocessing represents an added cost.
Shipment of Fuel to Another Utility or Site for Storage
The shipment of fuel to another utility for storage would provide
short-term relief from the storage problem at WBN. The Nuclear Waste
Policy Act and 10 CFR Part 53, however, clearly places the
responsibility for the interim storage of spent fuel with each owner or
operator of a nuclear plant. The shipment of fuel to another source is
not an acceptable alternative because of increased fuel handling risks
and additional occupational radiation exposure, as well as the fact
that no additional storage capacity would be created.
Reduction of Spent Fuel Generation
Improved usage of fuel and/or operation at a reduced power level
would decrease the amount of fuel being stored in the pool and thus
increase the amount of time before full core off-load capacity is lost.
With extended burnup of fuel assemblies, the fuel cycle would be
extended and fewer offloads would be necessary. The licensee is
planning on operating on an 18-month refueling cycle, and, as part of
this proposed amendment, the licensee plans on increasing its fuel
enrichment to 5 percent. Operating the plant at a reduced power level
would not make effective use of available resources, and would cause
unnecessary economic hardship on TVA and its customers. Therefore,
reducing the amount of spent fuel generated by increasing burnup
further or reducing power is not considered a practical alternative.
Development of Onsite Independent Storage Facility
An independent spent fuel storage installation (ISFSI) is licensed
under 10 CFR Part 72. It is a passive storage system which stores spent
fuel in dry casks on a concrete platform in a secured area. There are
no commercial ISFSIs operating in the United States. Although use of an
ISFSI provides many benefits, the site-specific development of an
independent dry fuel storage facility at WBN was deemed undesirable by
the licensee compared to the use of the already existing, licensed
spent fuel racks. Furthermore, construction of such a facility would
not use the existing expansion capacity of the existing pool, would not
use the existing spent fuel racks taken out of the Sequoyah plant, and
would have the potential to cause additional and different
environmental impacts due to activities related to construction and
operation. Development of a site-specific ISFSI at this time and in
rsponse to TVA's current needs would waste available resources.
No Action Taken
If no action were taken, the storage capacity could be lost as
early as 2000 and WBN would have to shut down. This alternative is
considered a waste of available resources and is not considered viable.
Environmental Impacts of the Proposed Action:
Radiological Impact
The WBN has waste treatment systems designed to collect and process
waste that may contain radioactive material. The radioactive waste
treatment systems were evaluated in the Final Environmental Statement
(FES) and its supplement. The Spent Fuel Pool Cooling and Cleaning
System is designed to remove the decay heat generated by stored spent
fuel assemblies and to clarify and purify the water to permit
unrestricted access to the plant fuel storage area and maintain optical
clarity of the spent fuel pool water. It is not expected that there
will be an increase in the liquid release of radionuclides from the
plant as a result of the spent fuel pool expansion. Although the amount
of activity in the spent fuel pool cleanup system may increase due to
the increased number of spent fuel assemblies and the enrichment, after
processing by the liquid radioactive waste system, the amount of
activity released to the environment as a result of the proposed change
is expected to be negligible. The proposed amendment will not involve
any change in the radioactive waste treatment systems or flowrates
described in the FES and its supplement.
Because the racks are being removed from the WBN plant before any
spent fuel has been stored in them, they are not contaminated and they
will not contribute to the volume of solid radioactive waste.
Additionally, the Sequoyah racks are being reused and are not
classified as solid radioactive waste at this time. No additional low
specific activity waste output is generated and less solid waste will
be generated due to the reuse of the spent fuel racks and removal of
the existing racks before they become contaminated.
In addition to the spent fuel assemblies themselves, the only other
solid radioactive waste generated by the spent fuel pool is the spent
fuel pool polisher resin which is used for water clarity. These resins
are replaced approximately once per refueling cycle. No additional
resins are expected to be generated by the pool cleanup system;
therefore, no significant increase in the volume of solid radioactive
waste is expected with the proposed amendment.
The proposed amendment is not expected to significantly affect the
doses to the workers in the fuel storage area. The licensee stated that
pressurized water reactor experience has shown that area radiation dose
rates are approximately 1-3 millirem/hour. Dose rates on the pool
bridge crane platform are approximately 4-5 mrem/hr. During refueling
operations, these rates may increase slightly. During the reracking
procedures, the occupational exposure to the workers will be much less
if the amendment is granted at this time rather than if the racks are
taken out in the future, after spent fuel is stored in them. No
increases are expected to the concentration of airborne radioactivity
as a result of expanded storage capacity.
The environmental impacts on the uranium fuel cycle and
transportation resulting from the use of higher enrichment fuel and
extended irradiation were published in NUREG/CR-5009, ``Assessment of
the Use of Extended Burnup Fuels in Light Water Power Reactors,'' and
discussed in the staff Environmental Assessment and Finding of No
Significant Impact published in the Federal Register on February 29,
1988 (53 FR 6040). The staff concluded that no significant adverse
effects will be generated by increasing the burnup levels as long as
the maximum rod average burnup level of any fuel rod is no greater than
60 Gwd/MtU. The staff also stated that the environmental impacts
summarized in
[[Page 18373]]
Table S-3 and S-4 for a burnup level of 33 Gwd/MtU are conservative and
bound the corresponding impacts for burnup levels up to 60 Gwd/MtU and
uranium-235 enrichments up to 5 wt%.
Based on the above, the staff concludes that there are no
significant radiological environmental impacts associated with the
proposal.
Non-Radiological Impact
The proposed amendment does not modify land use at the site; no new
facilities or laydown areas are needed to support the rerack or
operation after rerack; therefore, the proposal does not affect land
use or land with historical or archeological sites.
As a result of the proposal, steady state pool bulk temperature
remains within the limits prescribed for the spent fuel pool to satisfy
pool structural strength constraints. The increased spent fuel
inventory results in a maximum bulk pool temperature increase of less
than 10 deg.F. This increase in temperature results in an increase in
pool water evaporation rate. The original analysis was performed
assuming two unit operation. The licensee reanalyzed the effects of the
increased temperature and evaporation rate and found the increases were
well within the capacity of the existing HVAC system and continued to
be bounded by the original analysis. The total heat load for the
unplanned emergency core off-load is less then 35 million BTU/hr, which
is less than one percent of the total plant heat loss.
The proposal does not affect non-radiological plant effluents and
no changes to the National Pollution Discharge Elimination System
(NPDES) permit are needed. The proposal does not result in any
significant changes to land use or water use, or result in any
significant changes to the quantity or quality of effluents; no effects
on endangered or threatened species or on their habitat are expected.
The proposal will not change the method of generating electricity
nor the method of handling any influent from the environment or non-
radiological effluents to the environment. Therefore, no changes or
different types of non-radiological environmental impacts are expected
as a result of the amendment.
Accident Considerations
In its application, the licensee evaluated the possible
consequences of postulated accidents and described the means for
mitigating these consequences should they occur. This evaluation
included spent fuel handling accidents. A fuel handling accident may be
viewed as a reasonably foreseeable design basis event which the pool
and associated structure, systems, and components are designed and
constructed to prevent. On the basis of its analysis, the licensee
concluded that the effects of the proposed TS changes are small and
that the calculated consequences are within regulatory requirements and
staff guideline dose values.
The staff evaluated the consequences of operation at a bounding
value of burnup (60,000 MWD/T) because of the licensee's reference to
the use of more highly enriched fuel (up to 5.0 weight percent U-235).
The staff concluded that the only potential increased radiological
consequences resulting from a fuel handling accident associated with
extended burnup and higher fuel enrichment are the thyroid doses; these
doses remain well within the acceptance criteria given in NUREG-0800
and are, therefore, acceptable. The environmental impacts of the
accident were found not to be significant.
The staff has considered accidents whose consequences might exceed
a fuel handling accident that is beyond design basis events. The
licensee and staff, as part of the operating license review, performed
an analysis of installation of severe accident mitigation design
alternatives (SAMDAs) in the environmental impact review. The staff
concluded that none of the five design improvements warranted
implementation at WBN.
The staff believes that the probability of severe structural damage
occurring at WBN is extremely low. This belief is based on the
Commission's requirements for the design and construction of the spent
fuel pool and the contents and on the licensee's adherence to approved
industry codes and standards. Therefore, the staff concludes that the
potential for environmental impact from severe accidents is negligible.
Summary
The Commission has completed its evaluation of the proposed action.
The change will not increase the probability or consequences of
accidents, no changes are being made in the types of any effluents that
may be released offsite, and there is no significant increase in the
allowable individual or cumulative occupational radiation exposure.
Accordingly, the Commission concludes that there are no significant
radiological environmental impacts associated with the proposed action.
With regard to potential nonradiological impacts, the proposed
action does involve features located entirely within the restricted
area as defined in 10 CFR Part 20. It does not affect nonradiological
plant effluents and has no other environmental impact. Accordingly, the
Commission concludes that there are no significant nonradiological
environmental impacts associated with the proposed action.
Alternative Use of Resources
This action does not involve the use of any resources not
previously considered in the FES for WBN Units 1 and 2, dated April
1995.
Agencies and Persons Consulted
In accordance with its stated policy, on March 24, 1997 the staff
consulted with the Tennessee State official, Ms. E. Flanagan of the
Division of Radiological Health, regarding the environmental impact of
the proposed action. The State official had no comments.
Findings of No Significant Impact
The staff has reviewed the proposed spent fuel pool modification to
WBN Unit 1 relative to the requirements set forth in 10 CFR Part 51.
Based upon the environmental assessment, the staff has concluded that
there are no significant radiological or non-radiological impacts
associated with the proposed action and that the proposed license
amendment will not have a significant effect on the quality of the
human environment. Therefore, the Commission has determined, pursuant
to 10 CFR 51.31, not to prepare an environmental impact statement for
the proposed amendment.
For further details with respect to the proposed action, see the
licensee's letter dated October 23, 1996, as supplemented by letters
dated December 11, 1996, January 31, February 10 and 24, March 11 and
April 4, 1997, which are available for public inspection at the
Commission's Public Document Room, The Gelman Building, 2120 L Street,
NW., Washington, DC, and at the local public document room located at
the Chattanooga-Hamilton County Library, 1001 Broad Street,
Chattanooga, Tennessee.
Dated at Rockville, Maryland, this 7th day of April 1997.
For The Nuclear Regulatory Commission.
Frederick J. Hebdon,
Director, Project Directorate II-3, Division of Reactor Projects--I/II,
Office of Nuclear Reactor Regulation.
[FR Doc. 97-9661 Filed 4-14-97; 8:45 am]
BILLING CODE 7590-01-P
