ML17199T432

Safety Evaluation Supporting Util 831101 Response to Generic Ltr 83-28,Item 2.1 (Part 1), Equipment Classification

ML17199T432
Person / Time
Site:	Dresden
Issue date:	11/09/1987
From:	NRC
To:
References
GL-83-28, NUDOCS 8711190371
Download: ML17199T432 (2)

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I UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION GENERIC LETTER 83-28, ITEM 2.1 (PART 1) EQUIPMENT CLASSIFICATION COMMONWEALTH EDISON COMPANY DRESDEN NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-237 AND 50-249

1.0 INTRODUCTION

AND

SUMMARY

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 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 (EDO), 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-100, 11Generic Implications of the ATWS Events at the Salem Nuclear Power Plant.

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• As a result of this investigation, the Commission (NRC) requested (by the Generic Letter 83-28 dated July 8, 19831 ) 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.

This report is an evaluation of the response submitted by Commonwealth Edison Company, the licensee for the Dresden Nuclear Power Station, Units 2 and 3 for Item 2.1 (Part 1) of Generic Letter 83-28.

The actual documents reviewed as part of this evaluation are listed in the references at the end of the report.

Item 2.1 (Part 1) requires the licensee to confirm that all Reactor Trip System components are identified, classified and treated as safety-related as indicated in the following statement:

Licensees and applicants shall confirm that all components whose functioning is required to trip the reactor are identified as safety-related on documents, procedures, and information handling system used in the plant to control safety-related activities, including maint~nance, work orders, and parts replacement.

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.. PDR i.I LJ 2.0 EVALUATION The licensee for the Dresden Nuclear Power Station. Units 2 and 3 responded to the requirements of Item 2.1 (Part 1) with submittals dated Novembers. 1983 2 and July 26, 19853

• The licensee stated in these submittals that some components that are part of the reactor trip system such as turbine trip components are not included in the category of components that are required to trip the reactor, however, the licensee has confirmed that all components that are required to perform the reactor trip function were reviewed to verify that these components are classified as safety-related equipment.

The licensee further stated that these components were identified as such in the plant's licensing basi~ documentation and are also identified as safety-related in all procedures, documents, and information handling systems that control safety-related activities such as maintenance work and parts procurement for safety-related activities.

3.0 CONCLUSION

Based on our review of these responses, we find the licensee's statements confirm that a program exists for identifying, classifying and treating components that are required for performance of the reactor trip function as safety related. This program meets the requirements of Item 2.1 (Part 1) of the Generic Letter 83-28, and is therefore acceptable.

4.0 REFERENCES

1.

NRC letter, D. G. Eisenhut to all Licensees of Operating Reactors, Applicants for Operating License, and Holders of Construction Permits, "Required Actions Based on Generic Implications of Salem ATWS Events {Generic Letter 83-28)," July 8, 1983.

2.

Letter, P. L. Barnes, Commonwealth Edison Company, to H. R. Denton, NRC, November 5, 1983.

3.

Letter, G. L. Alexander, Commonwealth Edison Company, to H. R. Denton, NRC, July 26, 1985.

Principal Contributor:

D. Lasher Dated: November 9, 1987