ML14192A676
| ML14192A676 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 08/05/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML14192A675 | List: |
| References | |
| GL-83-028 NUDOCS 8508210339 | |
| Download: ML14192A676 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 0X SUPPLEMENTAL SAFETY EVALUATION H. B. ROBINSON 2 GENERIC LETTER 83-28, ITEM 4.3 REACTOR TRIP BREAKER AUTOMATIC SHUNT TRIP INTRODUCTION AND
SUMMARY
Generic Letter 83-28 was issued by NRC on July 8, 1983, indicating actions to be taken by licensees based on the generic implication of the Salem ATWS events.
Item 4.3 of the generic letter requires that modifications be made to improve the reliability of the Reactor Trip System by implementation of an automatic actuation of the shunt attachment on the reactor trip breakers. By letters dated December 27, 1984, and February 18, 1985, the licensee, Carolina Power and Light Company (CP&L), provided responses to the plant-specific questions identified by the staff in its August 10, 1983, Safety Evaluation Report of the generic Westinghouse design. Subsequent to the review of CP&L's submittal, the staff issued a safety evaluation report indicating the acceptable and unacceptable aspects of the design and requested CP&L to resubmit it for staff's approval.
On May 17,-1985, CP&L initiated a phone conversation with the staff to discuss the unacceptable aspects of the design.
By letter dated May 20, 1985, CP&L resubmitted the proposed design for the incorporation of the automatic actuation of the shunt trip attachments for the reactor trip breakers.
The staff has reviewed the licensee's proposed design for the automatic actuation of the reactor trip breaker shunt trip attachments and finds it acceptable.
350210339 850805 PDR ADOCK 0)5000261
-2 The licensee has already implemented the shunt trip modifications and has planned to install the bypass breaker position status light including the cell switch interlock during refueling outage #11 which is scheduled to begin in May 1987.
EVALUATION The staff identified the following concerns in its safety evaluation report of H. B. Robinson 2 issued on April 1, 1985 (The item numbers referred to below are keyed to this report):
(a) Submission of revised information including revised electrical schematics showing; (i) provision of bypass breaker position status lights on the main
-control board (ii) inclusion of cell switch interlock for bypass breaker position indication as detailed in item 1.
The licensee states that CP&L will modify the main control board to provide bypass breaker position status lights including the cell switch interlock for breaker position indication. The bypass breaker position lights will only indicate when the breaker is in 'operate' position and will be classified as Class 1E.
We find this commitment,to be acceptable.
-3 (b) Confirmation that shunt trip components have been seismically qualified as committed to in item 6.
CP&L has received and reviewed the WOG Equipment Qualification Test Report.
The DB-50 Shunt Trip Attachment (STA) was seismically tested. The test re sults demonstrated that the equipment tested remained within the specified performance and trip requirements. We find this to be acceptable.
(c) Confirmation that bypass breaker testing will demonstrate proper operation of control board bypass breaker position indication as identified in item 11.
The licensee will incorporate appropriate tests in the existing annual test procedure to demonstrate proper operation-of bypass breaker position status lights. We find this commitment to be acceptable.
(d) Submission of proposed technical specifications noted in item 13, following implementation of this modification.
Guidance for the Technical Specification discussed in (d) above have been issued to the licensee by Generic Letter 85-09 dated May 23, 1985.
-4 CONCLUSION Based on the review of the licensee's responses to the concerns identified in the staff's evaluation of the plant specific questions, we find that the proposed automatic shunt trip modifications are acceptable.
The implementation of the bypass breaker position status lights including the cell switch interlock should be confirmed by Region II. The implementation of the procedural change to demonstrate proper operation of bypass breaker position status lights should also be confirmed by Region II.