ML20154A405

Safety Evaluation Supporting 831108 Response to Generic Ltr 83-28,Items 3.1.1,3.1.2,3.2.1,3.2.2,4.1 & 4.5.1 Re post-maint Testing & Reactor Trip Sys Reliability.Salp Input Encl

ML20154A405
Person / Time
Site:	Haddam Neck, 05000000
Issue date:	11/14/1985
From:	NRC
To:
Shared Package
ML20154A404	List: ML20154A401 ML20154A405 ML20154A420
References
GL-83-28, TAC-52924, TAC-53073, TAC-53760, TAC-54070, NUDOCS 8603040031
Download: ML20154A405 (6)

Text

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SAFETY EVALUATION GENERIC LETTER 83-28, ITEMS 3.1.1, 3.1.2, 3.2.1, 3.2.2, 4.1 and 4.5.1 CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK NUCLEAR POWER PLANT DOCKET NO. 50-213 1

1.0 Introduction

{' On February 25, 1983, both of the scram circuit breakers at Unit 1 of the  :

Salem Nuclear Power Plant failed to open upon an automatic reactor trip signal from the reactor protection system. This incident occurred during the plant startup, and the reactor was tripped manually by the operator about 30 seconds af ter the initiation of the automatic trip signal. The failure of the circuit breakers has been determined to be related to the sticking of the undervoltage trip attachment. Prior to this incident, on February 22, 1983, at Unit 1 of the Salem Nuclear Power Plant, an auto-matic trip signal was generated based on steam generator low-low level during plant startup. In this case the reactor was tripped manually by the operator almost coincidentally with the automatic trip.

1 Following these incidents, on February 28, 1983, the NRC Executive Director for Operations (EDO), directed the staff to investigate and j report on the generic implicatior.s of these occurrences at Unit 1 of the Salem Nuclear Plant. The results of the staff's inquiry into the generic implications of the Salem unit incidents are reported in NUREG-1000,

" Generic Implications of ATWS Events at the Salem Nuclear Power Plant."

As a result of this investigation, the Director, Division of Licensing, Office of Nuclear Reactor Regulation requested (by Generic Letter 83-28 4 dated July 8,1983) all licensees of operating reactors, applicants for an i

operating license, and holders of construction permits to respond to cer-tain generic concerns. These are categorized into four areas; (1) Post-Trip Review, (2) Equipment Classification and Vendor Interface, (3) Post-Maintenance Testing, and (4) Reactor Trip System (RTS) Reliability Improvements. Within each of these areas various specific actions were delineated.

This safety evaluation (SE) addressed the following actions of Generic Letter 83-28:

3.1.1 and 3.1.2, Post-Maintenance Testing (Reactor Trip System Components) 3.2.1 and 3.2.2, Post-Maintenance Testing (All Other Safety-Related Components) g[0NO P

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Safety Evaluation  ?

4.1, Reactor Trip System Reliability (Vendor-Related Modifications) 4.5.1, Reactor Trip System Reliability (System Functional Testing)

By a letter dated November 8, 1983, Connecticut Yankee (the licensee) described their planned or completed actions regarding the above items for Haddam Neck Nuclear Power Plant.

2.0 Evaluation 2.1 General Generic Letter 83-28 included various NRC staff positions regarding the specific actions to be taken by operating reactor licensees and operating license applicants. The Generic Letter 83-28 positions and discussions of licensee compliance regarding Actions 3.1.1, 3.1.2, 3.2.1, 3.2.2, 4.1 and 4.5.1 for Haddam Neck are presented in the sections that follow.

2.2 Actions 3.1.1 and 3.1.2, Post-Maintenance Testing (Reactor Trip System Components)

Position Licensees and applicants shall submit the results of their review of test and maintenance procedures and Technical Specifications to assure that post-maintenance operability testing of safety-related components in the reactor trip system (RTS) is required to be con-ducted and that the testing demonstrates that the equipment is capable of performing its safety functions before being returned to service.

Licensees and applicants shall submit the results of their check of vendor and engineering recommendations (regarding ofety-related components in the RTS) to ensure that any appropriate test guidance is included in the test and maintenance procedures or the Technical Specifications, where required.

Discussion The licensee's response states that Technical Specifications and test and maintenance procedures for the trip system components have been reviewed and determined to have adequate post-maintenance opera-bility testing requirements for assurance of operability on return to service.

Safety Evaluation- 3 The licensee's response also states that recommendations on test guidance for test and maintenance procedures have been incorporated through either procedure revisions or revision of vendor technical manuals referenced in procedures, as appropriate. Implementation of these recommendations is tracked via an internal computerized com-mitment tracking system. In addition, current Technical Specifica-tions envelope any vendor requirements.

Based on the above, the licensee has complied with the NRC Staff position for Actions 3.1.1 and 3.1.2 of Generic Letter 83-28.

2.3 Actions 3.2.1 and 3.2.2, Post-Maintenance Testing (All Other Safety Related Components)

Position Licensees and applicants shall submit a report documenting the ex-tending of test and maintenance procedures and Technica' Specifica-tions review to assure that post-maintenance operability testing of all safety-related equipment is required to be conducted and that the testing demonstrates that the equipment is capable of performing its safety function before being returned to service.

Licensees and applicants shall submit the results of their check of vendor and engineering recommendations (regarding all other safety related components) to ensure that any appropriate test guidance is included in the test and maintenance procedures or the Technical Specifications, where required.

Discussion The licensee's response stated that post-maintenance operability testing requirements for all safety related components and deter-mined adequate for assuring operability on returning equipment to service. Additionally, recommendations on test guidance have been evaluated and/or incorporated in test and maintenance procedures as they are received. This is accomplished through revision of proced-ure or the vendor technical manuals which are referenced in proced-ures. These recommendations are tracked via, an internal computer-ized commitment tracking system.

Based on the above, the licensee has complied with the NRC Staff position for Actions 3.2.1 and 3.2.2 of Generic Letter 83-28.

Safety Evaluation a 2.4 Action 4.1, Reactor Trip System Reliability (Vendor-Related Modifications)

Position All vendor recommended reactor trip breaker modifications shall be reviewed to verify that either: (1) each modification has, in fact, been implemented; or (2) a written evaluation of the technical reasons for not implementing a modification exists.

For example, the modifications recommended by Westinghouse in NCD-Elec-18 for the 0B-50 breakers and a March 31, 1983 letter for the DS-416 breakers shall be implemented or a justification for not implementing shall be made available. Modifications not previously made shall be incorporated or a written evaluation shall be provided.

Discussion The licensee stated that they have reviewed the list of Westinghouse Technical Bulletins supplied by Westinghouse and determined that the three Bulletins applicable to their reactor trip breakers have been addressed and the necessary actions completed. This was verified by a review of the licensee's internal computerized commitment tracking system.

Based on the above, the licensee has complied with the NRC staff position for Action 4.1 of Generic Letter 83-28.

2.5 Action 4.5.1, Reactor Trip System Reliability (System Functional Testing) position On-line functional testing of the reactor trip system, including independent testing of the diverse trip features, shall be performed.

The diverse trip features to be tested include the breaker under-voltage and shunt trip features on Westinghouse, B&W, and CE plants; the circuitry used for power interruption with the silicon controlled rectifiers on B&W plants; and the scram pilot valves and backup scram valves (including all initiating circuitry) on GE plants.

Discussion On line testing can not be conducted at Haddam Neck. Justification is provided in 4.5.2 which will be reviewed by NRR.

Based on the above, the licensee has complied with the NRC staff position for Action 4.5.1 of Generic Letter 83-28.

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Safety Evaluation 5 a

3.0- Conclusion Based upon the foregoing discussions, the staff concludes that the licen-see is in compliance with Actions 3.1.1, 3.1.2, 3.2.1, 3.2.2, and 4.5.1 of Generic Letter 83-28.

Date: November 14, 1985 Principal Contributor: John A. Schumacher DRP k i

SALP INPUT Facility: Haddam Neck Docket No.: 50-213 TAC No's.: 52924, 53760, 53073, 54070 Requested Date: February 11, 1985, Memorandum Miraglia to Starostecki Functional Area: Adequacy of Licensee Submittal SALP INPUT The licensee submittal for response to Generic Letter 83-28, Salem ATWS event, was found to be adequately stated and enabled a clear understanding of the technical issues. The licensee's efforts to resolve staff questions concerning the issues was satisfactory.

Rating: Category 1