ML16341D941
| ML16341D941 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/27/1986 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML16341D940 | List: |
| References | |
| GL-83-28, NUDOCS 8611040019 | |
| Download: ML16341D941 (6) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION FOR GENERIC LETTER 83-28, ITEM 2. 1 (Part I)
E UIPMENT CLASSIFICATION (RTS COMPONENTS)
DIABLO CANYON NUCLEAR POWER PLANT, UNITS I AND 2 DOCKET NOS.
50-275 AND 50-323 INTRODUCTION AND
SUMMARY
On February 25,
- 1983, both of the scram circuit breakers at Unit I of the Salem Nuclear Power Plant failed to open upon an automatic reactor trip signal from the reactor protection system.
The 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 I 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 I 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 Events at the Salem Nuclear Power Plant."
As a result of this investigation, the NRC requested, by Generic Letter 83-28 dated July 8, 1983 (Ref. I) 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 the Pacific Gas and Electric Company, the licensee for the Diablo Canyon Nuclear Power Plant, Units I and 2, regarding Item 2. 1, Part I of Generic Letter 83-28.
Item 2. 1, Part I 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 of Generic Letter 83-28:
"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 systems used in the plant to control safety-related activities, including maintenance, work orders, and parts replacements."
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Item 2. 1, Part 2 is for the vendor interface and requires the licensee to establish, implement and maintain a continuing program to ensure tlat vendor information is complete, current and controlled throughout the life of the
- plant, and appropriately referenced and incorporated in plant instructions and procedures.
This safety evaluation pertains to Part 1 of Item 2. 1; the effort regarding Part 2 has not been completed.
The evaluation was performed by EGSG Idaho, the NRC contractor for Item 2. 1 reviews.
The contractor's
- report, "Conformance to Generic Letter 83-28, Item 2. 1 (Part
- 1) - Equipment gualification (RTS Components),"
is attached.
(Note:
the report addresses also the Catawba Units 1 and 2, the McGuire Units 1 and 2 and the Comanche Peak Units 1 and 2).
EYALUATION Pacific Gas and Electric Company (PGSE),
the licensee for the Diablo Canyon Nuclear Power Plant, Units 1 and 2, responded to the requirements of Item 2. 1, Part 1 with submittals dated November 7, 1983, January 24,
- 1985, and April 18, 1985 (Refs.
2, 3, and 4 respectively).
The licensee presented in the first two submittals a schedule for the resolution and status reports on the resolution of this item.
The third submittal stated that all components that are required to perform the reactor trip function were reviewed by the licensee to verify that these components are classified as safety-related equipment.
The'icensee further stated that a list of documents had been developed that identify and control activities that may affect the reactor trip system components.
CONCLUSION Based on the staff's review of these responses, the staff finds the licensee's statement confirm that a program exists for identifying, classifying and treating components that are required for the 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.
PRINCIPAL CONTRIBUTOR:
D. Lasher
REFERENCES:
1.
NRC Letter, DE 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 from J. 0. Schuyler (PGKE) to D.
G. Eisenhut (NRC), November 7
1983.
3.
Letter from J.
D. Shiffer (PGSE) to G.
W. Knighton (NRC), January 24, 1985 (DCL 85-025).
4.
Letter from J.
D. Shiffer (PGLE) to G.
W. Knighton (NRC) April 18, 1985 (DCL 85-151). '