[Federal Register Volume 65, Number 41 (Wednesday, March 1, 2000)]
[Notices]
[Pages 11097-11099]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-4890]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. STN 50-528, STN 50-529, and STN 50-530]


Arizona Public Service Company; Palo Verde Nuclear Generating 
Station, Units 1, 2, and 3, Environmental Assessment and Finding of No 
Significant Impact

    The U.S. Nuclear Regulatory Commission (NRC) is considering 
issuance of an amendment to Facility Operating Licenses Nos. NPF-41, 
NPF-51, and NPF-74, issued to the Arizona Public Service Company (the 
licensee), for operation of the Palo Verde Nuclear Generating Station 
(Palo Verde), Units 1, 2, and 3, located in Maricopa County, Arizona.

Environmental Assessment

Identification of Proposed Action

    The proposed action would increase the number of fuel assemblies 
that can be stored in the Palo Verde spent fuel pools (SFPs) from 1034 
fuel assemblies per SFP (1033 fuel assemblies for the Unit 2 SFP) to 
1205 fuel assemblies per SFP. The increase in storage capacity is based 
on taking credit for fuel assembly burnup, for soluble boron, and for 
fuel assembly configuration in the SFP. In addition, the proposed 
action would increase the maximum radially averaged fuel enrichment 
from 4.3 weight percent to 4.8 weight percent.
    The proposed action is in accordance with the licensee's 
application for amendments dated June 8, 1999, as supplemented by 
letters dated July 20 and November 24, 1999.

The Need for the Proposed Action

    The licensee is planning on implementing dry cask storage in the 
second half of 2002. Since all three Palo Verde SFPs will lose the 
capacity to fully offload the core prior to that time, the licensee 
needs to increase the maximum number of fuel assemblies that can be 
stored in the SFPs. The higher enrichment limit is needed to provide 
flexibility in future core designs.

Environmental Impacts of the Proposed Action

Thermal Impact
    The change in temperature of the SFP water was evaluated for the 
potential increase in reactivity. The current design basis for the SFP 
cooling system is based on the proposed increased capacity of the SFP, 
so no significant increase in SFP temperature is expected. In addition, 
because the reactivity coefficient in the SFP is negative, a 
temperature increase will result in a decrease in reactivity. Since 
increasing the capacity of the SFPs would increase the maximum heat 
load, the pool temperature would tend to be higher, not lower, after 
the proposed action was implemented. Therefore, the thermal impact of 
the proposed action would tend to increase the ability of the SFP 
system to maintain criticality parameters within the design bases of 
the plants.
    The increased heat loads that result from increasing the SFP 
capacity would cause the total heat load rejected to the environment to 
increase. The maximum increase in heat rejection to the environment is 
less than 0.1 percent of the total heat load rejected to the 
environment by an operating Palo Verde unit, and is not considered a 
significant impact to the environment.
Radioactive Waste Treatment
    The Palo Verde units use waste treatment systems designed to 
collect and process gaseous, liquid, and solid waste that might contain 
radioactive material. These radioactive waste treatment systems were 
evaluated in the Final Environmental Statement (FES) dated February 
1982 (NUREG-0841). The proposed increase in the capacity of the SFPs 
and the proposed increase in the enrichment limit will not involve any 
change in the waste treatment systems described in the FES.
Gaseous Radioactive Wastes
    The storage of additional and higher enriched spent fuel assemblies 
in the pools is not expected to affect the releases of radioactive 
gases from the SPFs. Gaseous fission products such as krypton-85 and 
iodine-131 are produced by the fuel in the core during reactor 
operation. A small percentage of these fission gases is released to the 
reactor coolant from the small number of fuel assemblies that are 
expected to develop leaks during reactor operation. During refueling 
operations, some of these fission products enter the pools and are 
subsequently released into the air. Since the frequency of refueling 
(and, therefore, the number of freshly offloaded spent fuel assemblies 
stored in the pools at any one time) will not increase, there would be 
no increase in the amounts of these types of fission products released 
to the atmosphere as a result of the increased pool fuel storage 
capacity.
    The increased heat load on the pools from the storage of additional 
spent fuel assemblies would potentially result in an increase in the 
pools' evaporation rate. However, this increased evaporation rate is 
not expected to result in an increase in the amount of gaseous tritium 
released from the pool. The overall release of radioactive gases from 
Palo Verde would remain a small fraction of the limits of 10 CFR 
20.1301.
Solid Radioactive Wastes
    Spent resins are generated by the processing of SFP water through 
the pools' purification system. These spent resins are disposed of as 
solid radioactive waste. Resin replacement is determined primarily by 
the requirement for water clarity and is normally done approximately 
once per year. No significant increase in the volume of solid 
radioactive waste is

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expected with the expanded storage capacity.
Liquid Radioactive Wastes
    The release of radioactive liquids would not be affected directly 
as a result of increasing the capacity of the SFPs. The SFP ion 
exchanger resins remove soluble radioactive materials from the pool 
water. When the resins are replaced, the small amount of resin sluice 
water that is released is processed by the radwaste systems. Resin 
replacement is determined primarily by the requirement for water 
clarity and is normally done approximately once per year. The increase 
in the amount of radioactive liquid released to the environment as a 
result of increasing the capacity of the SFPs is expected to be 
negligible.
Occupational Dose Consideration
    There are no physical modifications needed to increase the capacity 
of the Palo Verde SFPs, so no increase in occupational doses will 
result from this proposed action. The existing procedures for normal 
activities associated with handling fuel assemblies limit the 
radiological exposure for plant workers, and these limits are not 
affected by the higher enrichment limits or increased SFP capacity.
Accident Considerations
    The licensee evaluated three events related to the proposed action 
to verify that the previous accident analyses as incorporated in the 
plants' design bases remain bounding. They are a fuel handling 
accident, a fuel misloading event, and a boron dilution event.
    The design-basis fuel handling accident is the dropping of a single 
fuel assembly during fuel handling. Increasing the SPF capacity and 
increasing the enrichment limit does not affect the method of handling 
spent fuel or the design of the fuel handling equipment. The fuel 
assembly design (clad material and structural components) is not 
affected by this change. The equilibrium source term used in the fuel 
handling accident analysis is based on rated core thermal power and an 
infinite cycle, and therefore is independent of fuel assembly 
enrichment. Therefore, the radiological consequences of the fuel 
handling accident remains unchanged.
    The effect of a single misloaded spent fuel assembly on the SFP 
maximum effective multiplication factor has been analyzed and shown to 
remain within the design limit for this parameter (0.95). 
Therefore, the radiological consequences of a misloaded fuel assembly 
remains unchanged.
    Analyses were conducted to evaluate the possibility of unacceptable 
dilution of the soluble boron in the SFPs due to operational events or 
accidents. The analyses verified that the SFP maximum effective 
multiplication factor remained 0.95 for all credible 
accident scenarios. Therefore, the proposed action will not result in a 
criticality event and no increases in radiological consequences will 
occur as a result of a boron dilution event.
    The NRC has reviewed the above analyses conducted by the licensee 
and concludes that increases in the enrichment limit and in the 
capacity of the SFPs at Palo Verde will not be accompanied by an 
associated increase in the radiological consequences of fuel-handling 
accidents. The potential offsite doses will not be increased over the 
values given in the updated Final Safety Analysis Report.
Environmental Impact Conclusions
    The proposed action will not increase the probability or 
consequences of accidents, no changes are being made in the types of 
any effluents that may be released off site, and there is no 
significant increase in occupational or public radiation exposure. 
Therefore, there are no significant radiological environmental impacts 
associated with the proposed action.
    With regard to potential nonradiological impacts, the proposed 
action does not involve any historic sites. It does not affect 
nonradiological plant effluents and has no other environmental impacts. 
Therefore, there are no significant nonradiological environmental 
impacts associated with the proposed action.
    Accordingly, the NRC concludes that there are no significant 
environmental impacts associated with this action.
Alternatives to the Proposed Action
Shipping 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. To date, 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 the spent fuel to the DOE repository is not 
considered a viable alternative to increased onsite fuel storage 
capacity at this time.
Shipping Fuel to a Reprocessing Facility
    Reprocessing of spent fuel from Palo Verde 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.
Shipping the Fuel Offsite to Another Utility
    The shipment of fuel to another utility would provide short-term 
relief from the fuel storage problems at Palo Verde. The Nuclear Waste 
Policy Act of 1982, Subtitle B Section 131(a)(1), however, clearly 
places the responsibility for the interim storage of spent fuel with 
each owner or operator of a nuclear plant. The SFPs at the other 
reactor sites were designed with capacity to accommodate spent fuel 
from those particular sites. Therefore, transferring spent fuel from 
Palo Verde to other sites would create storage capacity problems at 
those locations.
Alternatives Creating Additional Storage Capacity
    Alternative technologies that would create additional storage 
capacity include rod consolidation, dry cask storage, modular vault dry 
storage, and constructing a new pool. Rod consolidation involves 
disassembling the spent fuel assemblies and storing the fuel rods from 
two or more assemblies into a stainless steel canister that can be 
stored in the spent fuel racks. Industry experience with rod 
consolidation is currently limited, primarily due to concerns for 
potential gap activity release due to rod breakage, the potential for 
increased fuel cladding corrosion due to some of the protective oxide 
layer being scraped off, and because the prolonged consolidation 
activity could interfere with ongoing plant operations. Dry cask 
storage is a method of transferring spent fuel, after storage in the 
pool for several years, to high capacity casks with passive heat 
dissipation features. The licensee is planning on implementing dry cask 
storage at the Palo Verde site, but the SFPs will lose the capacity to 
fully offload the core prior to the time dry cask storage will be 
available. Vault storage consists of storing spent fuel in shielded 
stainless steel cylinders in a horizontal configuration in a reinforced

[[Page 11099]]

concrete vault. The concrete vault provides missile and earthquake 
protection and radiation shielding. Concerns for vault dry storage 
include security, land consumption, eventual decommissioning of the new 
vault, and high cost. The alternative of constructing and licensing new 
SFPs is not practical for Palo Verde because such an effort would 
require about 10 years to complete and would not be available in the 
time frame needed.
    The alternative technologies that could create additional storage 
capacity involve additional fuel handling with an attendant opportunity 
for a fuel handling accident, involve higher cumulative dose to workers 
affecting the fuel transfers, require additional security measures that 
are significantly more expensive, and would not result in a significant 
improvement in environmental impacts compared to the proposed action to 
increase the capacity of the current SFPs.
Reduction of Spent Fuel Generation
    Generally, improved usage of the fuel and/or operation at a reduced 
power level would be an alternative that would decrease the amount of 
fuel being stored in the SFPs and, thus, increase the amount of time 
before the maximum storage capacities of the SFPs are reached. However, 
operating the plant at a reduced power level would not make effective 
use of available resources, and would cause unnecessary economic 
hardship on the licensee and its customers. Therefore, reducing the 
amount of spent fuel generated by increasing burnup further or reducing 
power is not considered a practical alternative.
The No-Action Alternative
    The NRC staff also considered denial of the proposed action (i.e., 
the ``no-action'' alternative). Denial of the application would result 
in no significant change in current environmental impacts. The 
environmental impacts of the proposed action and the alternative action 
are similar.

Alternative Use of Resources

    This action does not involve the use of any resources not 
previously considered in the Final Environmental Statement for Palo 
Verde, Units 1, 2, and 3.

Agencies and Persons Contacted

    In accordance with its stated policy, on January 27, 2000, the 
staff consulted with the Arizona State official, Mr. Audbry Godwin of 
the Arizona Radiation Protection Agency, regarding the environmental 
impact of the proposed action. The State official had no comments.

Finding of No Significant Impact

    On the basis of the environmental assessment, 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 environmental impact statement for the proposed 
action.
    For further details with respect to the proposed action, see the 
licensee's letters dated June 8, July 20, and November 24, 1999, which 
are available for public inspection at the Commission's Public Document 
Room, Gelman Building, 2120 L Street, NW., Washington DC. Publicly 
available records will be accessible electronically from the ADAMS 
Public Library component on the NRC Web site, http://www.nrc.gov (the 
Electronic Reading Room).

    Dated at Rockville, Maryland, this 24th day of February 2000.

    For the Nuclear Regulatory Commission.
Mel B. Fields,
Project Manager, Section 2, Project Directorate IV & Decommissioning 
Division of Licensing Project Management, Office of Nuclear Reactor 
Regulation.
[FR Doc. 00-4890 Filed 2-29-00; 8:45 am]
BILLING CODE 7590-01-P