ML20004D376
| ML20004D376 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/07/1981 |
| From: | Udall M HOUSE OF REP., INTERIOR & INSULAR AFFAIRS |
| To: | Hendrie J NRC COMMISSION (OCM) |
| References | |
| NUDOCS 8106090320 | |
| Download: ML20004D376 (2) | |
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COMMITTEE ON INTERIOR AND INSULAR AFFAIRS
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The Honorable Joseph Hendrie Q g,g i,w McW1 3/
Chairman, Nuclear Regulatory Commissa,.on 3-
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Dear Mr. Chairman:
The record of the TMI inquiries indicates that during hot functional testing at TMI-2, a steam bubble developed in the high point of the pipe through which water flowed from the reactor pressure vessel to one of the sueam generators.
(This seems to be the event described on page 65 of the Report of the Senate Special Investigation into the TMI accident.)
During the event in question, considerable difficulty was encountered in condensing the steam bubble, and it app. ears that persons present at TMI-2 on March 28, 1979 recalled this event as they sought to take actions to restore c.irculation between the reactor pressure vessel and the. steam generators.
The recollection of the September 1977 event probably influenced judgements as to what would be required to restore circulation durinc the March 28 accident.
For example, Mr. Brian Mehler told NRC investigators that following closure of the PORV block valve there had been a plan to enter the reactor building for the purpose of manually opening a valve at the top of the hot-leg.
This plan was abandoned, however, once radiation levels prevented access to the valve in ques-Later in the day, in a conversation between Mr. Leland tion.
Rogers,- a -B&W engineer assigned to TMI, and B&W staff in Lynchburg, Virginia, Mr. Rogers, in disagreeing with advice that the primary-coolant system be filled, indicated that he believed this could not be done.
In apparent reference to the 1977 even*, Mr. Rogers said in that instance, it 1
took us sometting like four days to get out of that thing to try and cool A: down to where we could get that bubble condition out of there.
We've got a similar condition here."
While the September 1977 event would have seemed to have been i
a matter deserving of analysis in the NRC inquiries into the accident, no such analysis appears to have been undertaken.
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. - l I would appreciate the Commission's answering the following questions-
-- Was the September 1977 event reported to the NRC by the licensee?
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-- If it was not reported,1was there a requirement to report it to-the NRC at the t'ime it occurred?
-- When did NRC staff become aware of the September 1977 event?
What action was taken by the.
staff once they found out about it?
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-- Subsequent to the NRC learning of the event, what modifications in operating procedures, instrumenta-tion, and plant components have been required as a result of the staff's analysis of it?
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-- Could a steam bubble develop in the hot-legs
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of operating B&W reactors following a transient causing i
sudden cooling of the reactor coolant system?
If so, what actions would be taken to restore circulation?
-- On what dates were remotely controlled vents installed on high points in the hot-legs of B&W reactors?
l Thank you for your assistance.
i Sincerely, RRIS K. UDALL hairman 9
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