ML20214M149

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Safety Evaluation Supporting Util Responses to Generic Ltr 83-28,Item 2.1 (Part 2) Re Established Interface W/Nsss or Vendors of Each Component of Reactor Trip Sys
ML20214M149
Person / Time
Site: Maine Yankee, 05000000
Issue date: 05/21/1987
From:
NRC
To:
Shared Package
ML20214M128 List:
References
GL-83-28, NUDOCS 8706010194
Download: ML20214M149 (3)


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SAFETY EVALUATION REPORT MAINE YANKEE ATOMIC POWER PLANT DOCKET NO. 50-309 GENERIC LtlIER 83-28, ITEM 2.1 (PART 2)

Introduction and Summary On FebnJary 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 was terminated manually by the operator about 30 seconds after the initiation of the automatic trip signal.

The failure of the circuit breakers was 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 automatic trip signal was generated based on steam generator low-low level during plant start-up.

In this case, the reactor was tripped manually by the operator almost coincidentally with the automatic trip.

Following these incidents, on February 28, 1983, the NRC Executive Director for Operations (ED0), directed the staff to investigate and report on the generic implications of these occurrences at Unit 1 of the Salem Nuclear Power 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 the ATWS l

Events at the Salem Nuclear Power Plant." As a result of this investigation, 1

the Comission (NRC) requested (by Generic letter 83-28 dated July 8,1983 )

all licensees of operating reactors, applicants for an operating license, and holders of construction permits to respond to generic issues raised by the analyses of these two ATWS events.

8706010194 870521 PDR ADOCK 05000309 i

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. This report is an evaluation of the response submitted by Maine Yankee Atomic Power Company, the licensee for the Maine Yankee Atomic power Plant for Item 2.1 (Part 2) of Generic Letter 83-28. The actual document reviewed as part of this evaluation is listed in the references at the end of the report.

1 Item 2.1 (Part 2) requires the licensee / applicant to confirm that an interface has been established with the NSSS or with the vendors of each of the components of the Reactor Trip System which includes:

periodic communication between the licensee / applicant and the NSSS or the vendors of each of the components of the Reactor Trip System, and a system of positive feedback which confirms receipt by the licensee / applicant of transmittals of vendor technical information.

EVALUATION The licensee for the Maine Yankee Atomic Power Plant responded to the requirements 2

of Item 2.1 (Part 2) with a submittal dated 1une 18,1985. The response states that the Maine Yankee interface program includes annual contact with each RTS component vendor, vendor certification of the validity of Maine Yankee technical information, and a system of positive feedback from the component vendors.

CONCLUSION Based on our review of the licensee's response, we find that an acceptable vendor interface program exists with RTS component vendors for components that are re-quired for performance of the reactor trip function. This program meets the requirements of Item 2.1 (Part 2) of the Generic letter 83-28, and is therefore acceptable.

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. REFERENCES 1.

NRC Letter, n. G. Eisenhut to all Licensees of Operating Reactors, Applicants for Operating License, and Holders of Construction Permits,

" Required Actions Rased on Generic Implications of Salem ATWS Events (Generic Letter 83-28)," July 8,1983.

2.

Maine Yankee Atomic Power Company letter to NRC, G. D. Whittier to Director of Nuclear Reactor Regulations, " Generic letter 83-78, Item 2.1 and 2.2.7,"

June 18, 1985.

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