ML19322C626
| ML19322C626 | |
| Person / Time | |
|---|---|
| Site: | 05000273, Crane |
| Issue date: | 07/02/1979 |
| From: | Lanning W NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Parler W NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| Shared Package | |
| ML19322C624 | List: |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001180190 | |
| Download: ML19322C626 (1) | |
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JUL 2 1979 MEMORANDUM FOR: William Parler, Task Leader, Group 1 FROM:
Wayne D. Lanning, Group 1
SUBJECT:
ADDITIONAL PRECURSOR EVENT
Reference:
Cordle, H. et. al., Technical Report un Beznau Unit One Incident oflugust 20, 1974: TG-1 TRIP / REACTOR TRIP / SAFETY INJECTION ACTUATION, Westinghouse Report SA/251, September 2,1974 (Proprietary Information)
The Reference describes an incident at a foreign reactor which is similar to the e'.ent at TMI-2 and could have provided some insight into the behavior of the pressurizer level indication resulting from a failed-open relief valve.
A turbine trip on the Beznau reactor followed by failure of the steam dump system to operate resulted in a reactor trip and the opening of the pressurizer relief valves (2).
One of these valves subsequently failed to close and the resulting blowdown of the pressurizer resulted in the rupture of the pressurizer relief tank bursting disk.
Steam was formed in the RCS hot legs and the pressurizer level was high off-scale for 3 to 5 minutes.
The operator isolated the open relief valve, and the transient was mitigated in approximately 10 minutes after turbine trip.
-I c"ggast we determine if this event was reported by Westinnhnuso to the NRC or to its customers, If not, we should determine what Regulatory requiremen'ts are applicable (if any) and make an appropriate recommendation in our report.
Way D. Lanning Group 1 i 7 cc w/o encl.
Group 1 members
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8001180MC)
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