ML20147A743

Safety Evaluation Supporting Amends 98 & 93 to Licenses DPR-19 & DPR-25,respectively

ML20147A743
Person / Time
Site:	Dresden
Issue date:	02/19/1988
From:	Office of Nuclear Reactor Regulation
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Shared Package
ML20147A729	List: ML20147A743
References
NUDOCS 8803010323
Download: ML20147A743 (3)

Text

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 98 TO PROVISIONAL OPERATING LICENSE NO. DPR-19 AND AMENDMENT NO. 93 TO FACILITY OPERATING LICENSE N0. DPR-25 COMMONWEALTH EDIS0N COMPANY DRESDEN NUCLEAR POWER STATI6N, UNIT NOS. 2 AND 3 DOCKET NOS. 50-237/249

1.0 INTRODUCTION

By letter dated August 26, 1986 the Commonwealth Edison Company (CECO or the licensee) subnitted a request to amend Provisional Operation License No.DPR-19, which authorized operations of Dresden Nuclear Powers Unit No.

2, and Facility Operating License No.DPR-25, which authorizes operation of Dresden Nuclear Power Station Unit No. 3.

The proposed amendments would delete certain diesel generator testing requirements to eliminate unnecessary and excessive testing.

In addition, a one and one-half hour maintenance period would be allowed without requiring low pressure core cooling surveillance.

By letter dated July 2,1984 the staff issued Generic Letter 84-15 to all licensees of operating reactors, applicants for operating licenses and holders of construction permits. The subject of Generic Letter 84-15 is "Proposed Staff Actions To Improve And Maintain Diesel Generator Reliability." The main thrust of the GL 84-15 is toward reducing the number of cold fast starts of diesel generators and of lowering the number of required diesel generator starts in general to reduce the potential degrading effects of too frequent testing. The reliability of Emergency Diesel Generators (EDG) is one of the main factors affecting the risk from station blackout and thus the improvement of EDG reliability can reduce the risk of core damage from station blackout events.

In addition to this, the letter addressed the testing of diesel generators as required in some eariter plants when emergency core cooling systems (ECCS) are declared inoperable. The staff was concerned with the number of unnecessary EDG tests for the earlier licensed operating plants f

which are required under their current Technical Specifications (TS) to

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perform frequent testing for ECCS equipment out of service. No such TS requirements exist for the recently licensed plants.

In an effort to reduce excessive testing of EDGs in these earlier plants and amend their TS to reflect comparable testing with that of Standard Technical yc Specifications, Generic Letter 84-15 recomended that the surveillance requirements for testing EDGs, because of inoperability of emergency core cooling systems, be deleted from plant unique TS.

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l 2.0 EVALUATION By submittal dated August 26, 1986, CECO proposed changes to Dresden Technical Specification Surveillance Requirements 4.5.A.2, 4.5.A.4, 4.5.A.5 and 4.5.B.3 to eliminate the diesel generator testing when core spray, low pressure coolant injection pump, low pressure coolant injection subsystem and containment cooling subsystem are declared inoperable.

Failures experienced in the above mentioned systems will not affect the performance of diesel generators. Testing of the diesel generator under such circumstances is not warranted. The staff has reviewed the proposed change and finds this proposed change is in accordance with the Generic Letter 84-15, Standard Technical Specifications, and is in the interest of reducing the potential for diesel engine degradation due to frequent testing, and is, therefore, acceptable.

The licensee has proposed an addition to the Technical Specification 3.9.B.2.b which would allow a diesel engine to be taken out of service for a 1 1/2 hour period of preventative maintenance.

This period shall not be allowed unless two offsite lines are available and the alternate diesel generator has been proven operable. The addition of this specification will reduce the number of core spray, low pressure coolant injection and containment cooling service water surveillance which must be performed when a diesel engine is taken out of service for minor maintenance. This Technical Specification change was already approved on similar plants like Quad Cities. The staff has reviewed this proposed change and based on the review finds the change does not degrade the safety of the plant, is consistent with Generic Letter 84-15 and is, therefore, acceptable.

In addition to the changes discussed above, a paragraph on page 3/4 9-4 of the Unit 2 Technicc1 Specifications which included a one-time extension of the 2/3 diesel generator outage time was no longer pertinent and was removed. This is a purely administration action and is acceptable.

Also, for convenience, pages 3/4 9-5 and 3/4 9-6 for each unit have been reproduced to show relocation of paragraphs. No change to the content of the Technical Specifications is involved. During the review no change was found on page 3/4 5-4 of Unit 3, therefore, that page is not included-in this amendment.

3.0

SUMMARY

The licensee has proposed to delete from the Technical Specifications the requirements of testing diesel generators while emergency core cooling system is inoperable.

Based on our review we find that this is in accordance with the engineering rationality used in GL 84-15 and is, therefore, acceptable.

Based on our review we also find that the addition of a requirement in the I

Technical Specification which would allow a diesel engine to be taken out I

of service for a 1 1/2 hour period of preventative maintenance is, acceptable.

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4.0 ENVIRONMENTAL CONSIDERATION

These amendments involve changes to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes to the surveillance j

requirements. The staff has detennined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no j

significant increase in individual or cumulative occupational radiation exposure. The Comission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public coment on such finding. Accordingly, these amendments i

meet the eligibility criteria for categorical exclusion set forth in 10 CFR51.22(c)(9).

Pursuant to 10 CFR 51.22(b) no environmental impact statement nor environmental assessment need be prepared in connection with the issuance of these amendments.

5.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, i

that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations and the issuance of these amendments will not be inimical to the comon defense and security nor to the health and safety of the j

public.

Principal Contributor:

N. Trehan i

Dated: February 19, 1988

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