ML20050J919
| ML20050J919 | |
| Person / Time | |
|---|---|
| Issue date: | 04/02/1982 |
| From: | Stello V Committee To Review Generic Requirements |
| To: | Dircks W NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| References | |
| RTR-REGGD-74.003. NUDOCS 8204140202 | |
| Download: ML20050J919 (4) | |
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APR 21982 A
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y, MEMORANDUM FOR: William J. Dircks S
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Executive Director for Operations FROM:
Victor Stello, Jr., Chairman T
Comittee to Review Generic Requirements f,
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SUBJECT:
MINUTES OF CRGR MEETING NO.11 The Comittee to Review Generic Requirements met on Wednesday, March 24, 1982, from 1-5 pm. Attendance at the meeting is shown in the Enclosure.
The following matters were considered:
1.
Mr. Guzy of RES presented the proposed Regulatory Guide SC78-4,
" Qualification and Acceptance Tests for Snubbers Used in Systems Important to Safety." The Comittee requested that further information be provided on the questions below in order that the Guide can be reconsidered at a future meeting.
(a) In view of the potential $20-40 million cost that could result from implementing the proposed Reg. Guide, what safety problems would be corrected by this Guide that warrant these costs?
are there less costly alternatives?
to what degree would snubber problems still persist because of improper installation, maintenance or operational problems?
(b) What is the expected increase in occupational exposure associated with implementing the proposed Reg. Guide?
(c) Are there less prescriptive alternatives than Appendix A, which appearsto be a purchase specification for snubbers, to achieve the goal of improved snubber performance?
(d) Why and to what extent is 10 CFR 50 Appendix B, Quality Assurance, required by the proposed Reg. Guide?
(e) What is the safety basis for the proposed implementation plan?
(f) What is the design basis for the acceptance criteria in the proposed Reg. Guide (for example, water hamer loads)?
(a) Why is rule linouaae. "shall" and "shall not," used in the
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William J. Dircks 2.
Dr. Fattson of NRR presented a status sunriary on TMI Action Plan Task II.F.2, " Instrumentation for Detection of Inadequate Core Cool i ng."
The discussion centered on the instrumentation systems proposed by PWR vendors for measuring reactor coolant level. The Committee did not reach a decision on a recomendation concerning the proposed systems pending further information from NRR on total ICC system costs and certain other questions regarding how the system is to be used by the operators. Nonetheless, the Committee agreed with the general approach outlined by NRR.
The impetus for considering the need for additional instrumentation to detect inadequate core cooling came from the experience of TMI.
One of the most important lessons from that accident was that the operators required more information on the status of core cooling during an accident than was available in the control room at the time. This realization led to early actions by NRC to require the installation of Subcool fionitors (SM) in PWR control rooms and to upgrade the number and quality of core-exit thermocouples (TC) in PWRs. Even with this added instrumentation, however, there remained, during a small LOCA, a period of time after the system reaches saturated conditions (indicated by SM) but before the core has boiled dry (indicated by TC) when the operators have insufficient information to track the inventory of coolant in the vessel and primary system.
It was to fill this gap that NRR has required extensive further studies by the industry to determine whether additional instrumentation could be provided to monitor the status of core cooling.
Based on the discussions with NRR and review of extensive material prepared by NRR and industry, the Committee reached the following l
preliminary conclusions:
(a) Additional instrumentation to detect ICC would be highly desirable to complement the current package of Subcool Monitors and thermocouples.
(b) Rather than requiring an unambiguous indication of water level in the vessel (which is probably not possible), it is probably sufficient to require only a void indication or inventory tracking system to aid the operators in the period between saturation and core dryout.
(c) A differential pressure system and a heated junction thermocouple system appear to be acceptable methods for void indication or tracking inventory.
(d) Other means, such as reactor coolant pump electrical current suggested by the LOFT project, may also be beneficial for "racHnn conlant density (and hence inventory) under Dumns on condi ti6n.
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APR 2 1982 William J. Dircks (e) The instruments comprising the ICC package should be viewed as a whole, not individually, and clear guidelines should be developed on the use and limitations of each instrument in the ICC package.
l (f) If a void indication or inventory tracking system is utilized, it should not be made operational until after appropriate Emergency Operating Procedure Guidelines for the overall ICC package are reviewed and approved. The system should be factored into the task analysis portion of the Detailed Control Room Design Review by the licensee, and operators should be trained in its operation and limitations.
(g) The cost-benefit assessment should be based on consideration of the costs of the overall package, including the need for redundancy and qualification requirements.
The Committee requested that this topic be reviewed again after receipt of further information from NRR.
nnginal DiGno4 by yictcEStcPV Victor Stello, Jr., Chairman Committee to Review Generic Requirements
Enclosure:
List of Attendees cc: CRGR Members Office Directors G. Cummingham, ELD l
Commission (5) t Distribution:
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.p, CRGR MEETING NUMBER 11 ATTENDANCE RECORD (March 24,1982)
CRGR MEMBERS Vic Stello, Jr.
Bob Bernero
.Darrell Eisenhut Ed Jordan Jack Heltemes Joe Scinto Don Mausshardt OTHERS t
Walt Schwink, DEDROGR Tom Murley, DEDROGR Stephn Stern, NRR Tom Cox, DEDROGR
- - John Austin,- OEDO B. D. Liaw, OCM Ed Blackwood, DEDROGR
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Yueh-Li C. Li, NRR Bob Erickson, NMSS Mat Taylor, DEDROGR Richard J. Kiessel, IE i
Jim Richardson, RES D. Guzy, RES H. Shaw, NRR Reger Mattson, NRR Larry Phillips, NRR Les Rubenstein,.NRR s
Tai Huang, NRR' Ed Abbot, OCM t
l Ned Kondich, RES Dom Tondi, DHFS l
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