ML20027C691
| ML20027C691 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 06/16/1981 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Michelson C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20027A769 | List: |
| References | |
| FOIA-82-338 NUDOCS 8210270096 | |
| Download: ML20027C691 (2) | |
Text
.
6 y
f*.g..=,eog(g g //[
g_
UNITED STATES
,y g NUCLEAR REGULATORY COMMISSION 3 g
- , E WASHINGTON, D. C. 20555
- e ar,...../
JUN 16198h MEMORANDUM FOR: Carlyle Michelson, Director Office for Analysis and Evaluation of Operational Data FROM: Harold R. Denton, Director Office of Nuclear Reactor Regulation
SUBJECT:
PROPOSED ABNORMAL OCCURRENCE - PRESSURE TRANSIENTS DURING SHUTDOWN AT A NUCLEAR POWER PLANT We have reviewed your draft Commission Paper dated June 3,1982 on the above subject and we note that it reflects the information given to your staff informally by the Materials Engineering Branch, the Reactor Systems Branch, the Operating Reactors Assessment Branch and the Project Manager. It is also consistent with the supporting information supplied by these NRR branches for the May 19, 1982 meeting with Commissioner Roberts, his technical assistant and the technical assistants from other Commissioner's offices. Two additional comments are attached for the purpose of strengthening the Abnormal Occurrence write-up. On the basis of our review, we concur with the draft Commission Paper which proposes the Turkey Point Unit 4 low temperature overpressure events as an Abnormal Occurrence. w Harold R. Denton, Director Office of Nuclear Reactor Regulation
Attachment:
Conments /t-3 B2y0g96 820920 p ARNOLDB2-338 PDR N
-f,. COMMENTS ON DRAFT COMMISSION PAPER ON THE PROPOSED ABNORMAL OCCURRENCE PRESSURE TRANSIENTS DURING SHUTDOWN AT A NUCLEAR POWER PLANT 1. On page 4 of the Abnormal Occurrence write-up, three reasons are given for the inoperability of the Overpressure Mitigating System. The second reason (root isolation valve leakage) should be eliminated since it did not actually contribute to the system inoperability. 2. On page 6 of the Abnormal Occurrence write-up the cause of the event is described as the " automatic closure of the RHR system suction isolation valves." It is more accurate to describe the event cause as the initial pressure pulse which resulted in the RHR system isolation. With regard to this initial pressure pulse the cause is not presently known. However, heat input from the steam generators (following the RCP startup) could have been a contributor and should be investigated. The plant Technical Specifications require a temperature difference of less than 50 F (between the SG's and the ) RCS) before reactor coolant pump start. This aspect of the event apparently has not been investigated. e -A}}