ML19253B267
| ML19253B267 | |
| Person / Time | |
|---|---|
| Issue date: | 06/29/1979 |
| From: | Catton I Advisory Committee on Reactor Safeguards |
| To: | Okrent D Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1141, NUDOCS 7910100567 | |
| Download: ML19253B267 (2) | |
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UNITED STATES y ' ! i-/ ~- '[,7, NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS o, h 5
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SUBJECT:
'IDPICS FOR JULY 11,1979 'IMI-2 IMPLICATIONS SUBCOMMITfEE MEETIN3 There are a number of topics that would be of interest to me.
Some may have been covered at meetings I've missed. Rey are as follows:
(1) Results of studies by CE and W task forces. Both CE and W met with the Staff during the past couple of weeks to present their evaluations of safety implications of mI-2.
(2)
In-plant existing instrumentation that could reasonably be upgraded for use in accident circumstances. Ackerman, an NRC consultant, did a great deal with 'IMI-2 instrumentation during the few days following the accident. Kaufman, from LOPT, used range detectors to estimate core voiding.
I would like to hear from Ackerman what he thinks about present plant instrumentation.
I don't believe one needs high accuracy to follow the accident - but if it is demanded one is faced with a formidable task.
(3) Control room computer systems for data processing. W e mI-2 system is antiquated. hhat is the state-of-affairs in other plants? I could find very little in communication between NRC and the plant owners about information to be made available to operators. With cheap off-the-shelf equipnent now avaiable, that is an order of magnitude improvement over the mI-2 system, I would like tc l mow what is being asked of the utili-ties in this area.
(4) Desigi. requirements for RHR systems. At 'IMI-2 it was not clear that anybody, There in particulate B&W, knew how long the RHR could be expected to operate.
was concern about radiation damage to valve packing and pump seals among others.
A brief presentation of today's ideas about how an RHR system should perform when stressed would be informative.
(5) Procedures for emergency action.
I would like to see how one gets from engineer-ing a remedy for a dangerous situation to procedures for an operator that one has confidence in, will be properly implemented. It would be of interest to see an example carried through frcrn beginning to end. Se guidelines shown us by B&W are motherhood.
(6) Feedwater piping design criteria. B&W and the Staff state that design criteria presently in use preclude waterhammer. We question is: Do the criteria in-clude situations such as occurred at mI-2 where valves closed upstream of a running ptznp.
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-COPY-D. Okrent June
, 1979 (7) Scram vs. possible opening of a PORV. It's not clear to me why a better PORV wasn't required instead of changing setpoints and requiring a scram for turbine trip. It is clear that the method chosen is the most expedi-tious.- But, is it the best? Is concern for improper operator action reason enough? Why not better equignent and procedoers?
Safety-grade requirements. What is the rationale for deciding what equip-(8) ment and instrumentation must meet safety-grade requirements when it inter-faces with a safety system.
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