ML20125D472
| ML20125D472 | |
| Person / Time | |
|---|---|
| Issue date: | 12/04/1992 |
| From: | Amy Cubbage Office of Nuclear Reactor Regulation |
| To: | Rosalyn Jones Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9212150215 | |
| Download: ML20125D472 (3) | |
Text
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W ASHINGTON, D C. 20555
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December 4, 1992 MEMORANDUM FOR:
Robert C. Jones, Chief Reactor Systems Branch Division of Systems Safety and Analysis THRU:
Timothy E. Collins, Chief g BWR Reactor Systems Sec. ion Reactor Systems Branch Division of Systems Safety and Analysis FROM:
Amy E. Cubbage, Reactor Systems Engineer BWR Reactor Systems Section Reactor Systems Branch Division of Systems Safet, and Analysis
SUBJECT:
MEETING
SUMMARY
FROM NUMARC MEETING ON PWR WATER LEVEL INSTRUMENT ERRORS At the request of industry, a meeting was held with NUMARC on December 1,1992 to discuss current industry activities to assess and address potential inaccuracies of Pressurized Water Reactor (PWR) water level instrumentation caused by the evolution of dissolved non-condensible gas during and after rapid depressurization events.
The list of attendees is provided in the enclosure, and a summary of the issues discussed is provided below,
[he purpose of the meeting was to discuss industry activities concerning Information Notice No. 92-54, " Level Instrumentation Inaccuracies Caused by Rapid Depressurization,"
dated July 24, 1992, and a letter from the NRC to each of the PWR owners' groups, dated October 19,1992,- requesting industry (3 address potential inaccuracies of level instrumentation used a PWRs.
The NRC discussed the engoing activities of the, Boiling Water Reactor Owners' Group (BWROG) and the staff to resolve potential inaccuracies in level indication-at BWRs-including the issuance of Generic letter No. 92-04, dated August 19, 1992.
The staff stated that there is currtntly no reason to believe that similar errors could not occur in level instrumentation used at PWRs. The staf f did note, however, that there are significant-differences in the operation of PWRs versus BWRs, and that we do not expect errors in PWR level indication to be as safety significant as errors in BWR level indication.
-The staff requested NUMARC and the owners' groups to evaluate the followirg concerns with respect to pressurizer level instrumentation, steam generator level instrumantation, and reacter vessel level instrumentation:
(1)
Do non-condensible gases affect PWR level instrumentation; t
1 0; (2)
Do pctential errors in level indication 4:ffect automatic safety system a
responce;-and g
(3)
Do potential-errors in idel indication affect operator rnponse in exercish Q._., O~: - _ y the Emergency Operating Procedures (EOPs).
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Robert C. Jones -
December 4, 1992 The-staff also requested that industry evaluate the poss!bility that errors in level-indication may result in prolonged operation of the pressurizer heaters.
The' staff is aware that prolonged energization of the pressurizer heaters can result -in failure of the reactor pressure vessel boundary, as discussed in the October 19, 1992 letter to the PWR.
owners' groups, t
Jim Taylor of the B&W Owners' Group stated that this issue was. previously discussed with the staff in connection with the B-SAR-review. He also stated that industry had performed tests in which a reference leg saturated with hydrogen was rapidly depressurized.
There were no significant errors until approximately 400 psi.
Industry and the staff agreed that the issue may have been addressed in part in the past, but that it was important to make sure that the issue is completely addressed for all licensees and that any cautions be added to or changes be made to the plant procedures if necessary.
NUMARC and the owners' groups committed to respond to our October 19 letter by the end of January 1993.
They agreed to inform us as soon as possible of any change in this schedule.
The process that was used to adenss this issue was also discussed at this meeting.
Industry expressed a concern that the staff should have initially persued this issue i
through NUMARC, instead of directly contacting the owners' groups.
The staff noted the concern, and st.ated that the staff will look into determining the best way to handle similar issues in the futu m.
/s/
Amy E. Cubbage, Reactor Systems-Engineer
-8WR Reactor Systems Section Reactor Systems Branch Division of Systems Safety and Analysis
Enclosures:
As stated cc w/ehelosure:
DISTRIB0fl0N:
A. Thadani Centralrfiles. "
PDR-SRXB R/F RJones TCollins-TQuay JClifford ACubbage ACubbage R/F OFFICIAL RECORD COPY l
Document Name: G:mtgsum12.01 i
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ENCLOSURE MEETING ATTENDEFS.
NAME AFFillATION TELEPHONE R. Jones NRC
- 301-504-2895 T. Collins NRC 301-504-2897 A. Cubbage NRC-301-504-2875 R. Newton WOG/WEPG 414-231-2002 R. Burski CE0G/Entergy 504-739-6774
'. Taylur B&WOG/B&W.
804-385-2817
- f. Mattt 2
NUMARC 202-872-1280 J. Link B&WOG/GPUN-201-316-7015-K. Graney-Bechtel
?01-417-3299
~J. Raleigh Southern Technical Ser, Ices, Inc.
301-652-2500.
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