ML19254F974
| ML19254F974 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 11/02/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19254F973 | List: |
| References | |
| NUDOCS 7911190546 | |
| Download: ML19254F974 (2) | |
Text
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SAFETY EVALUATION MODIFICATION TO TECHNICAL SPECIFICATIONS FOR PILGRIM NUCLEAR POWER STATION UNIT 1 I.
INTRODUCTION The licensee Boston Edison Company, in its submittal of July 6, 1979, proposed certain modifications to the Technical Specifi-cations for the Pilgrim Nuclear Power Station Unit 1.
The staff's evaluation of three of these changes, Attachments A, E, and G to the licensee's letter, are presented in this report.
II.
EVALUATION A.
ATTACHMENT A In Attachment A, the licensee requested a change in the method for calibrating the APRM.
The essentk1 change was to introduce a false gain characteristic to compensate for core peaking factors.
It is the staff's position that the infomation presented in Attachment A does not provide sufficient information to demonstrate how the revised APRM calibration procedure satisfies Paragraph 4.20 of IEEE Std. 279-1971. Speci fi-cally, the staff is concerned that the proposed practice of purposely introducing a false calibration may result in a condition where in the operator will not be provided with accurate, complete, and timely information pertinent to APRM status and generating station safety. Therefore, this change cannot be supported by the staff.
B.
ATTACHMENT E In Attachment E, the licensee requested a change in the setting of the Automatic Depressurization System ( ADS) blowdown timer from "120 + 5 seconds" to " greater than ur equal 90 to less than or equal to 120 seconds." The purpose of this change is to assure that the actual value used is less than that used in the ECCS analyses (120 seconds) and to provide margin in setpoint to account for calibration errors and drift.
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.. The lower value is sufficiently greater than the High Pressure Coolant Injection System (HPCI) starting time (25 seconds) and (in the licensee's opinion) the response time of a trained operator to maintain the probability of false initiation of the ADS at an acceptably low level.
C.
ATTACHMENT G
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In Attachment G, the licensee has provided additional surveillance testing requirements and calibration require-ments for the Intennediate Range Monitors.
This addition was requested by the NRC Office of Inspection and Enforcement.
III. CONCLUSION Based on our review of the licensee's submittal, we conclude that the modification requested in Attachment A does not satisfy the requimments of IEEE Std. 279-1971 and it should, therefore, be reje:ted. On a similar basis, we conclude that the modifications to the Technical Specifications that are presented in Attachments E and G do satisfy the requirements of IEEE Std. 279-1971 and are, therefore, acceptable.
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