[Federal Register Volume 59, Number 70 (Tuesday, April 12, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-8695]


[[Page Unknown]]

[Federal Register: April 12, 1994]


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

 

Arizona Public Service Co., et al.; Palo Verde Nuclear Generating 
Station Units 1, 2, and 3 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-41, NPF-51, and NPF-74 issued to Arizona Public Service Company, 
(the licensee), for operation of Palo Verde Nuclear Generating Station 
Units 1, 2, and 3 located in Wintersburg, Arizona.

Environmental Assessment

Identification of Proposed Action

    The proposed action would revise the provisions in the Technical 
Specifications (TS) related to increasing the pressurizer safety valve 
(PSV) setpoint tolerance from +/-1 percent to +3 percent and -1 
percent, increasing the main steam safety valve (MSSV) setpoint 
tolerance from +/-1 percent to +/-3 percent, reducing the high 
pressurizer pressure trip setpoint (HPPT) response time from 1.15 
seconds to 0.5 second, and reducing the Technical Specifications 
minimum auxiliary feedwater (AFW) pump flow requirement from 750 
gallons per minute (GPM) to 650 GPM.
    The proposed action is in accordance with the licensee's 
application for amendment dated November 13, 1990, as supplemented by 
letters of additional information dated May 27, 1992, May 13, 1993, and 
November 12, 1993.

The Need for the Proposed Action

    The proposed changes to the TS are required in order to provide the 
licensee with operational flexibility in meeting surveillance 
requirements for auxiliary feedwater (AFW) flow, and pressurizer safety 
valve (PSV) and main steam safety valve (MSSV) lift setpoint 
tolerances. The proposed change to the TS also involves a reduction of 
the high pressurizer pressure trip (HPPT) response time. This reduction 
is necessary to ensure that the peak pressures during postulated 
accident scenarios for the other changes (AWF, PSV, and MSSV) do not 
violate safety limits.

Environmental Impact of the Proposed Action

    The Commission has completed its evaluation of the proposed 
revision to the TS and the licensee's assessment of increased 
radiological release as a result of the safety valve setpoint tolerance 
change and the proposed reduction in auxiliary feedwater flow. For the 
most limiting SGTR scenario, this results in an increase in the 2-hour 
thyroid dose from 200 rem to less than 248 rem. Adding the increased 
dose due to the expanded PSV and MSSV setpoint tolerances (which the 
licensee calculated as a 5-percent dose increase), results in a 2-hour 
dose of 260 rem. This value provides adequate margin to the 10 CFR part 
100 guideline of 300 rem. The licensee also evaluated radiological 
release for the reactor coolant pump (RCP) shaft seizure event, and 
determined that the calculated 0.5 rem increase was insignificant 
compared to the 246 rem dose reported in Supplement 2 to the staff's 
Safety Evaluation Report related to the Combustion Engineering Standard 
Safety Analyses Report (CESSAR) for System 80, and the 300 rem SRP 
acceptance criteria. The staff finds the analysis results, utilizing 
proper conservatisms, to be within 10 CFR guidelines.
    Therefore, the proposed changes do not significantly 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 this proposed action would result in no significant radiological 
environmental impact.
    With regard to potential nonradiological impacts, the proposed 
changes do not affect nonradiological plant effluents and have no other 
environmental impact. Therefore, the Commission concludes that there 
are no significant nonradiological environmental impacts associated 
with the proposed amendment.
    The Notice of Consideration of Issuance of Amendment and 
Opportunity for Hearing in connection with this action was published in 
the Federal Register on December 27, 1990 (55 FR 53220). Two petitions 
for leave to intervene and request for hearing were filed following 
this Notice. One request was denied and the other granted. However, the 
party that was granted the hearing later voluntarily withdrew their 
contention.

Alternative to the Proposed Action

    Since the Commission concluded that there are no significant 
environmental effects that would result from the proposed action, any 
alternatives with equal or greater environmental impacts need not be 
evaluated.
    The principal alternative would be to deny the requested amendment. 
This would not reduce environmental impacts of plant operation and 
would result in reduced operational flexibility.

Alternative Use of Resources

    This action does not involve the use of resources not previously 
considered in the Final Environmental Statement related to operation of 
the Palo Verde Nuclear Generating Station Units 1, 2, and 3, dated 
February 1982 (NUREG 0841).

Agencies and Persons Consulted

    The staff consulted the State of Arizona official regarding 
environmental impact of the proposed action. The State official had no 
comments.

Finding of No Significant Impact

    Based upon the foregoing environmental assessment, 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 for the 
proposed license amendment.
    For further details with respect to this action, see the licensee's 
application for amendment dated November 13, 1990, and supplemented by 
letters of additional information dated May 27, 1992, May 13, 1993, and 
November 12, 1993, which are available for public inspection at the 
Commission's Public Document Room, Gelman Building, 2120 L Street, NW., 
Washington, DC 20555 and at the local public document room at the 
Phoenix Public Library, 12 East McDowell Road, Phoenix, Arizona 85004.

    Dated at Rockville, Maryland, this 6th day of April 1994.

    For the Nuclear Regulatory Commission.
Theodore R. Quay,
Director, Project Directorate IV-3, Division of Reactor Project III/IV, 
Office of Nuclear Reactor Regulation.
[FR Doc. 94-8695 Filed 4-11-94; 8:45 am]
BILLING CODE 7590-01-M