ML20246L994

Environ Assessment & Finding of No Significant Impact Re Amends to Licenses DPR-80 & DPR-82.Amends Would Revise Tech Specs by Revising Steam Generator Low & Low Low Level Setpoints for Initiating Reactor Trip

ML20246L994
Person / Time
Site:	Diablo Canyon
Issue date:	03/15/1989
From:	Knighton G Office of Nuclear Reactor Regulation
To:
Shared Package
ML20246M000	List: ML20246L994
References
NUDOCS 8903270005
Download: ML20246L994 (4)

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l 7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION i,

PACIFIC GAS AND ELECTRIC COMPANY DOCKETS NOS.'50-275 AND_50-323 DIABLO CANYON NUCLEAR POWER PLANT, UNIT N05. 1 AND 2 ENVIRONMENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT r

The U.S. Nuclear Regulatory Commission (the Comission) is considering issuance of amendments to Facility Operating License Nos. DPR-80 and DPR-82, issued to Pacific Gas and Electric Company (the licensee), for operation of the Diablo Canyon Nuclear Power Plant, Unit Nos. I and 2, respectively, located in San Luis Obispo County, California.

ENVIRONMENTAL ASSESSMENT Identification of Proposed Action:

The proposed amendments would revise the Technical Specifications (TS) by revising the steam generator low and low-low level setpoints for initiating a reactor trip. Specifically, the proposed amendments would change the DCNPP combined Technical Specifications by revising TS 2.2.1, " Reactor Trip System Instrumentation Setpoints," Table 2.2-1, " Reactor Trip System Instrumentation l

Trip Setpoints," Items 13 and 14. The.:e Items would be modified to reduce the i

steam generator water level low and low-low setpoints from 15 percent to 7.2 percent, as indicated by the narrow range instrument. Also, the associated TS l

1 bases would be changed accordingly.

The proposed action is in accordance with the licensee's application for amendments dated-April 18, 1988.

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_The Need for the Proposed Action:

i The proposed revision to the TS is required to decrease the number of unnecessary reactor trips ' caused by (1) steam generator water level low-low and(2)steamgeneratorwaterlevel-low,coincidentwithsteam/feedwaterflow f

mismatch. This will reduce the nunber of challenges to the reactor protection systems and impose fewer thermal transients on the plants.

Environmental Impacts of the Proposed Action:

The Comission has completed its evaluation of the proposed revision to the TS. Theevaluationshowsthattheproposedrevision(1)doesnotincrease the probability or consequences of accidents, (2) does not result in a change in the. types or amount of any effluents that may be released offsite, and (3)

~ does not result in a significant increase in the individual or cumulative occupational radiation exposure. Accordingly, the Comission concludes that this proposed action would result in no significant radiological environmental impact.

With regard to potential nonradiological impacts, the proposed revision to the TS involves systems located within the restricted area as defined in i

10 CFR Part 20.

It does not affect nonradiological plant effluents and has no other environmental impact. Therefor'e, the Comission concludes that there are no significant nonradiological environmental impacts associated with the l

proposed amendments.

The Notice of Consideration of Issuance of Amendment and Opportunity for Hearing in connection with this action was published in the FEDERAL REGISTER l

on June 23,1988(53FR23708). No request for hearing or petition for leave to intervene was filed following this notice.

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l Alternative to the Proposed Action:

Since the Comission has 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 amendments. This would not reduce environmental impacts of plant operation and would result in unne'cessary reactor trips, thereby increasing the number of challenges to the reactor protection systems and imposing more thermal transients on the plants.

Alternative Use of Resources:

This action does not involve the use of any resources not previously considered in the Final Environmental Statement related to the Diablo Canyon Nuclear Power Plant dated May 1973, and its Addendum, dated May 1976, Agencies and Persons Consulted:

The Commission's staff reviewed the licensee's request and did not consult other agencies or persons.

FINDING OF NO SIGNIFICANT IMPACT The Commission has determined not to prepare an environmental impact statement for the proposed license amendments.

Based upon the foregoing environmental assessment, we conclude that the proposed action will not have a significant effect on the quality of the human environment.

For further details with respect to this action, see the application for amendments dated April 18, 1988, which is available for public inspection at the Commission's Public Document Room, 2120 L Street, NW., Washington,

i DC 20555, and at the California Polytechnic State University Library, Goternment Documents and Maps Department, San Luis Obispo, California 93407.

Dated at Rockville, Maryland, this 15th day of March 1989.

FOR THE NUCLEAR REGULATORY COMMISSION l

George. Knight, Director Projec Directo te V Division of Reactor Projects - III, IV, V & Specia? Projects l

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