ML19308B709
| ML19308B709 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/24/1979 |
| From: | Deyoung R NRC - NRC THREE MILE ISLAND TASK FORCE |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19308B703 | List: |
| References | |
| TASK-TF, TASK-TMR NTFTM-790724-02, NTFTM-790724-2, NUDOCS 8001160776 | |
| Download: ML19308B709 (2) | |
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NTFTM. 790724-02 O
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Reactor RegulationHarold R. Denton, Director, Office of
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FROM:
j Richard DeYoung, Deputy Staff Director
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SUBJECT:
NRCLTMI Special Inquiry Group
'g PRECURSOR EVENT IN A FOREIGN REACTOR
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We understand that in 1974 a small LOCA occurred at a foreign r I
that is very similar to the TMI incident.
eactor incident steam formed in the RCS hot leg causinDuring the course of the rise while RCS pressure continued to decrease. g pressurizer level to caused pressurizer level to increase despite the fact that primary This void formation coolant was still bein system in this design,g released from the system. ' The protective low pressurizer level and low RCS pressure for safety inje automatically initiated.
This combination of coincident initiating o be signals and increasing pressurizer level caused the failure of injection to initiate while a small LOCA was occurring U.S. reactors have the same coincident logic for initiating saf t Since many injection, they are susceptible to the same problem ey the ECCS system could be deceived by this transient and its effIn addi have been confused by the pressurizer level indic ect on from this transient.
u e Despite the significance and relevance of this incident to U S to our knowledge this incident has never been re;iorted to th
.. reactors, vendor involved.
Act of 1974 require the reporting of defects and nonco e NRC by the We understand that individuals subject to Part 21 need to report f il e NRC.
or defects in foreign reactors that could create a substantial safety a ures
' hazard in facilities and activities in the United States.
incident should have been reported by the vendor Based on the T * -.-
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accident..
cerning this event be forwarded to us as soon as poss 1
con-should include as a minimum!
This infonnation,.
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July 24, 1979 1.
A description of who within the tiRC became aware of this event, by what mans was knowledge.of this event formally or informally received by the NRC, and when was knowledge T.'.
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
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its applicability to domestic reactors.
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A discussion of the regulatory requirements associated with the reporting of this event to the NRC by the vendor both
'after and prior to the THI accident.
4.
A discussion of the basis for a'ny decisions to release to the.public information associated with this event.
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We request that we be kept informed of the status and eventual resolution of this matter.
Richard DeYoung Deputy Staff Director HRC/TMI Special Inquiry Group i-DISTRIBUTION TERA RDeYoung KCornell T':
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