ML19322C514
| ML19322C514 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/27/1979 |
| From: | Parler W NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | Cornell K, Deyoung R Office of Nuclear Reactor Regulation, NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001170843 | |
| Download: ML19322C514 (1) | |
Text
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I " R.. : e. f i f ;[ G Lil. A i Ull Y C O,'/,if !SSl()N m a w..u c. a July 27,1979 flote to:
K. Cornell R. DeYoung
SUBJECT:
f4LETING ON PRECURSOR EVEitT Ill A FOREIGN COUNTR Kevin Cornell asked me to set up a meeting with liRC staf on this subject. A copy of the trerr.o dated July 24, 1979, from R. DeYoung to H. Denton on this subject is attached.
A meetin9 has been set for 2:00 p.m., Tuesday, July 31, 1979, in our conference room with Joe Lat leur and Howard Faulkner,who are from IP, and with Jerry Cook, OELD.
It is my understanding that they want to discuss question 4 in the memo referred to above. This discussion should also involve the basic question of whether the meno should be classified, how, when, and under what con-ditions tha NNC beccme aware of the infornation, whir is discussed in the memo.
W. Parler
Enclosure:
cc of memo dtd 7/24/79 fr R. DeYoung to H.
Denton cc: fi. Rogovin G. Frampton liebdon i
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kly a61979
-In Reply Refer to:
NTFTM 7 90 7 3 - o s
. MEMORANDUM FOR:
Harold R. Denton, Director Office of Nuclear Reactor Regulation FROM:
Richard DeYoung, Deputy Staff Director NRC/TMI Special Inquiry Group
SUBJECT:
PRECURSOR EVENT IN A FOREIGN REACTOR
/
We understand that in 1974 a small LOCA occurred at a foreign reactor that is very similar to the TMI incident. During the course of the incident steam formed in the RCS hot leg causin rise while RCS pressure continued to decrease. g pressurizer level to This void formation coolant was still being released from the system. caused pressuriz The protective system in this design, which is similar to many U.S. reactors, required low pressurizer level and low RCS pressure for safety injection to be automatically initiated.
This combination of coincident initiating signals and increasing pressurizer level caused the failure of safety injection to initiate while a small LOCA was occurring.
i Since many U.S. reactors have the same coincident logic for initiating safety injection, they are susceptible to the same problem.
In addition, if the ECCS system could be deceived by this transient and its effect on pressurizer level, then operators of plants with other designs could have been confused by the pressurizer level indication that resulted from this transient.
Despite the significance and relevance of this incident to U.S. reactors, to our knowledge this incident has never been repe:ted to the NRC by the vendor involved.
Act of 1974 require the reporting of defects and noncomplianc
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We understand that individuals subject to Part 21 need to report failures hazard in facilities and activities in the United States.or defects in Based on the insights resulting from the TMI accident, it would appear that this incident should have been reported by the vendor following the TMI accident.
We request that all relevant information currently available to NRR con-cerning this event be fonvarded to us as soon as possible.
This infomation should include as a minimum!
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A description of who within the NRC became aware of this event, by what means was knowledge.of this event fonnally or informally received by the NRC, and when was knowledge of the event acquired.
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A discussion of the basis for any decisions that have been made concerning the safety significance of this event and its applicability to domestic reactors.
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A discussion of the regulatory requirements associated with
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A discussion of the basis for any decisions to release to
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L We request that we be kept informed of the status and eventual resolution
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Deputy Staff Director NRC/TMI Special Inquiry Group DISTRIBUTION
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