ML16342B203
| ML16342B203 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 04/10/1986 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML16341D705 | List: |
| References | |
| GL-83-28, NUDOCS 8604220004 | |
| Download: ML16342B203 (4) | |
Text
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%**y4 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION GENERIC LETTER 83-28, ITEMS 3. 1. 1 AND 3. 1.2 PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON NUCLEAR POWER PLANT, UNIT NOS.
1 AND 2 J
DOCKET NOS. 50-275 AND 50-323 INTRODUCTION.
Oa 1'ebruary 25, 1983, duriag startup of the Salem Unit '1 plant, both circuit breakers in the Reactor Trip System failed to open automatica'ly upon receipt of a valid trip signal.
As a result of that event, the NRC's Office of Inspection and Enforcement issued IE Bul1.etin 83-01 which described the eveat and requested specified prompt corrective and preveative actions by licensees.
As the cause and ramifications of the event vere more clearly developed, the NRC's Office of Nuclear Reactor Regulation issued oa July 8, 1983, Generic I,etter 83-28, "Required Actions Based oa Generic Implications of Salem ATWS Eveats."
This letter addressed issues related to reactor trip system reliability and general management capability.
The letter was seat to all licensees of operating
- reactors, applicants for operating licenses and holders of constructioa permits.
One of the areas of reactor trip system reliability considered in Generic I.etter 83-28 (GL 83",28), is that of post-maintenance testing of reactor trip system components.
This is identified in GL 83-28 as /tern 3.1.
. This evaluation addresses the acceptability of the responses to parts 3.1.1 and 3.1.2 of this item, provided by the Pacific Gas and Electric Company (the licensee) for Diablo Canyon Units No.
1 and 2
(the facility),
EVAIUATION Items 3.1.1 and 3.1.2 of GL 83-28 state as follows:
"I. 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 is required to be conducted and that the testing demonstrates that the equipment is capable of pe[forming its safety functioas before beiag returned to service-
"2.
licensees aad applicants"shall'ubmit the results of their check of, vendor and engineering recommendations to ensure that any
" appropriate test guidance is included in the test and maintenance
- procedures or Technical Specificatioas, where required."'604220004 860410 PDR ADOCK 05000275 P
4
The licensee's responses to these requests were contained in let'ters dated November 7, 1983, and January 2 and April 18, 1985.
Regarding Item 3.1.1, the licensee stated in the letter of January 2,
1985 for Unit 1 and in Enclosure 1
of the letter dated April 18, 1985 for Unit 2, that facility "...Administrative Procedure NPAP C-6 ensures that Surveillance Tests are conducted after main-tenance is performed on safety-related components."
In addition, in response to a staff request, the licensee's letter of April 18, 1985, specifically confirmed that the post-maintenance testing demonstrates the components are capable of performing the required safety functions.
Regarding Item 3. 1.2, the licensee's responses of January 2, 1985 for Unit 1 and April 18, 1985 for Unit 2 stated that applicable vendor and engineering recommendations had been reviewed to ensure appropriate test gui.dance was
=
included in maintenance procedures and technical specifications.
The licensee also stated in the January 2,
1985 submittal that for Unit 1 over 95 percent of all recommendations were addressed by the utility's procedures, and that nine recommendations were still being reviewed.
In response to a staff
- request, the licensee stated in the letter of April 18, 1985 that for Unit 1 review of the final nine recommendations had been completed; and appropriate procedure revisions had been made for the recommendations determined to be applicable.
The licensee also stated that for Unit 2 all recommendations have been incorporated into the appropriate maintenance procedures.
CONCLUSION Based on the licensee s confirmation that post-maintenance operability testing is required to be performed on safety-related equipment and that such testing ensures the equipment is capable of performing its safety function prior to return to service, we conclude the licensee has acceptably satisfied for Diablo Canyon Unit Nos.
1 and 2, the actions requested by Item 3. 1.1 of Generic Letter 83-28.
Accordingly, this item is closed.
Based on the licensee's completion of a review of vendor and engineering recommendations and incorporation of applicable test guidance in the test and maintenance procedures for reactor trip system components, we conclude that the licensee has acceptably satisfied for Diablo Canyon Unit Nos.
1 and 2, the actions requested by Item 3. 1.2 of Generic Letter 83-28.
Accordingly, this item is closed.
Dated:
April 10, 1986 Principal Contributor:
G. Zwetzig
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