ML20215D622
| ML20215D622 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 10/07/1986 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20215D588 | List: |
| References | |
| GL-83-28, TAC-57374, NUDOCS 8610140230 | |
| Download: ML20215D622 (2) | |
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8 SAFETY EVALUATION REPORT FOR GENERIC LtIIER 83-28, ITEM 4.5.1 REACTOR TRIP SYSTEM RELIABILITY (SYSTEM FUNCTIONAL TESTING)
WOLF CREEK GENERATING STATION DOCKET: 50-482 I.
INTRODUCTION On February 25, 1983, both of the scram circuit breakers at Unit 1 of the l
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 after the initiation of the automatic trip signal. The failure of the circuit breakers has been determined to be related to the sticking of the under voltage trip attachment. Prior to this incident, on February 22, 1983, at Unit 1 of the Salem Nuclear Plant, an automatic 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. 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 ATWS Events at the Salem Nuclear Power Plant."
As a result of this investigation, the Commission (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 certain generic concerns. These l
concerns are categorized into four areas:
(1) Post-Tri (2)EquipmentClassificationandVendorInterface,(3) preview, Post-Maintenance Testing, and (4) Reactor Trip System Reliability Improvements.
The fourth action item. Reactor Trip System Reliability Improvements, consists of Action Item 4.1, " Reactor Trip System Reliability (Vendor-Related Modifications)," Action Item 4.2, " Reactor Trip System Reliability (Preventative Maintenance and Surveillance Program for Reactor Trip (Automatic Actuation of Shunt Trip Attachments forBreakers)." A Reliability Westinghouse and B&W Plants)," Action Item 4.4, " Reactor Trip System Reliability (Improvements in Maintenance and Test Procedures for B&W Plants)," and Action Item 4.5, " Reactor Trip System Reliability (System Functional Testing)." This safety evaluation report (SER) addresses Action Item 4.5.1 only.
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II.
REVIEW GUIDELINES The following review guidelines were developed after initial evaluation of the various utility responses to Item 4.5.1 of Generic Letter 83-28 ~
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and incorporate the best features of these submittals. As such, these B610140230 861007 PDR ADOCK 05000482 P
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4 review guidelines in effect represent a " good practices" approach to postmaintenance testing verification review. We have reviewed the licensee's response to Item 4.5.1 against these guidelines:
o The licensee or applicant shall submit a statement committing to independent, online functional testing of the diverse trip features.
III. EVALUATION AND CONCLUSION By letters dated February 29, 1984, and May 29, 1986, the licensee provided information regarding online functional testing of the reactor trip system. We have reviewed the licensee's response against the review guidelines as described in Section II. A brief description of the licensee's response and the staff's evaluation of the response against the review guidelines is provided below:
o The licensee stated that procedures for the online functional testing of the reactor trip system, including the independent testing of the diverse trip features were to be in place by fuel load. The NRC performed inspections prior to fuel load to assess the licensee's degree of conformance to Generic Letter 83-28. The NRC inspectors reviewed Technical Specifications, administrative procedures, surveillance procedures, and maintenance procedures, and found the specified system functional testing to be adequate.
Based on our review and the results of NRC inspections documented in NRC Inspection Reports 50-482/84-44, dated January 23, 1985, and 50-482/85-11, dated May 8, 1985, we conclude that the licensee's response to online functional testing of the reactor trip system for Wolf Creek Generating Station is acceptable.
Principal NRC Contributor:
R. Mullikin
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