ML20151L551

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Redistributed Safety Evaluation Supporting Amend 99 to License DPR-54
ML20151L551
Person / Time
Site: Rancho Seco
Issue date: 07/14/1988
From:
Office of Nuclear Reactor Regulation
To:
Shared Package
ML20151L494 List:
References
NUDOCS 8808040073
Download: ML20151L551 (3)


Text

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SAFETY EAVALVATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0.99TO FACILITY OPERATING LICENSE DPR-54 SACRAMENTO MUNICIPAL UTILITY DISTRICT RANCHO SECO NUCLEAR GENERATING STATION, UNIT 1 DOCKET N0. 50-312

1.0 INTRODUCTION

As a co;, sequence of the Salem Anticipated Transient Without Scram (ATWS) event, Generic Letter 83-28 established requirements for automatic actuation of a shunt trip attachment on reactor trip breakers. Furthermore, licensees were instructed to submit appropriate TS change requests prior to declaring the modified system operable. Guidance for submitting amendment requests was subsequently provided by the Commission's staff in Generic Letter 85-10.

By letter dated November 8, 1985, the licensee proposed changes to the Rancho Seco Technical Specifications pertaining to the reactor protection system instrumentation and surveillance requirements in response to Generic Letter 85-10. Generic Letter 85-10, dated May 23, 1985, specifies actions to be taken when one of the reactor trip breaker diverse trip features is inoperable, or when one of the silicone controlled rectifiers (SCR) relay channels is incoerable. Generic Letter 85-10 also specifies channel Functior.al Tests for the SCR relay channels and the reactor trip breakers, including independent verificatiori of the operability of the undervoltage and shunt trip attachments of the latter.

Subsequent to the licensee's November 8,1985 letter, the NRC reconynended an additional sentence to be included regarding actions to be taken on conditions of inoperable SCR relays. By letter dated December 9, 1986, the licensee supplemented its request to include the sentence and to add a pre-startup surveillance requirement which, through oversight, had not been included. -

2.0 EVALUATION The licensee's proposed Technical Specification changes would renumber existing Specification Section 3.5, "Instrumentation System," to incorporate actions to be taken in the event that one of the trip devices fails. We find this to be consistent with Action 9 of Generic Letter 85-10, and therefore acceptable.

The licensee proposes to modify the wording of Specification Section 3.5 to account for the fact that the reactor trip breakers now have two diverse trip teatures. We find this change to be acceptable.

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The licensee proposes to change and expand the Bases section to incorporate a descriptior,of the proposed changes. We find this change clarifies the maintenance response to be taken upon failure of one of the diverse trip features of the reactor (control rod drive) trip breakers. We find this change to be acceptable.

The licensee proposes to add a new specification to Section 3.5. This new specification (3.5.1.8) denotes actions to be taken if (a) one of the SCR relays in a channel is. inoperable or (b) if two or more of the SCR relays in a channel are inoperable. We find the proposed actions consistent with the actions permitted by an NRC letter dated December 6, 1985.* We therefore find this specification change to be acceptable.

The licensee proposes to add a new requirement (3.5.1.9) regarding the bypassing of a reactor trip breaker or SCR relay channel for surveillance testing. We find this specification to be consistent with action 7b of Generic Letter 85-10 and therefore acceptable.

The licensee proposes to make the following changes to Table 4.1-1 (Instrument Surveillance Requirements): The present items 13b and 13c wculd be renumbered to I?b and 12c and replaced by new items 13b and 13c pertaining to the reactor protection system (RPS) shunt trip and to the SCR relays, respectively. The RPS shunt trip and the SCR relays would be tested monthly and prior to startup (if not performed in the previous 7 {

days). We find these proposed changes to be consistent with Generic l Letter 85-10 and therefore acceptable.

In summary, we find that the Technical Specification changes recommended by Generic Letter 85-10 are applicable to Rancho Seco and that the ,

i proposed amendment is consistent with the guidance contained in Generic '

Letter 85-10. Generic Letter 85-10 was issued to ensure that the hardware  !

installed in response to Generic Letter 83-28 receives adequate testing i and surveillance and that ap)ropriate actions are taken if the installed 3 hardware is not operable. T1ese changes constitute additional controls l not presently included in the Technical Specifications.

3.0 ENVIRONMENTAL CONSIDERATION

This amendment involves changes in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes to surveillance requiremants. The staff has determined that the amendment involves 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 significant increase in individual or

  • NRG Letter, Frank Miraglia to Mr. J. Ted Enos, Chairman, ATWS Standing Committee, B&W Owners Group, December 6, 1985.

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o cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public coment on such finding.

Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b),

no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.

4.0 CONTACT WITH STATE OFFICIAL The NRC staff has advised the Chief of the Radiological Health Branch, State Department of Health Service, State of California, of the proposed determination of no significant hazards consideration. No coments were received.

5.0 C0f1CLUSI0ft We have concluded, based on the considerations discussed above, 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 (3) the issuance of the amendment will not be inimical to comon defense and security or to the health and safety of the public.

Principal Contributor: C. Y. Li Dated: July 14, 1988 l

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