ML20246F260
| ML20246F260 | |
| Person / Time | |
|---|---|
| Issue date: | 02/17/1989 |
| From: | Conran J Committee To Review Generic Requirements |
| To: | Bernero R, Goldberg J, Jordan E Committee To Review Generic Requirements, NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS), NRC OFFICE OF THE GENERAL COUNSEL (OGC) |
| References | |
| NUDOCS 8907130185 | |
| Download: ML20246F260 (5) | |
Text
_ _
. t j
DIASED TO WF Pn" I
h, _
UNITED STATES
'[*
g NUCLEAR REGULATORY COMMISSION l
3,
- j WASHINGTON, D. C. 20555 i
\\,...../
February 17, 1989 MEMORANDUM FOR:
. Edward L. Jordan, Chairman Robert M. Bernero, NMSS Jack R. Goldberg, OGC Carl J. Paperiello, RIII Denwood F. Ross, RES James H. Sniezek, NRR THRU:
C.J. Heltemes, Jr., Deputy Director Office for Analysis and Evaluation of Operational Data FROM:
James H. Conran SeniorProgramManager(CRGRSTAFF)
Office for Analysis and Evaluation of Operational Data
SUBJECT:
ISSUE IDENTIFICATION FOR MEETING NO. 158 AGENDA ITEM Enclosed for your information is an Issue Sheet for the proposed Generic Letter on MOV Testing and Surveillance, scheduled for review by the CRGR at Meeting No.158 in Room MNBB-6507 at 12:00 - 5:00 p.m. on Wednesday, February 22, 1989. If there are any questions, call me at 492-9855.
nn V c,~-s mes H. Conran SeniorProgramManager(CRGRStaff)
Office for Analysis and Evaluation of Operational Data
Enclosures:
As stated V cc: C. Sakenas C.J. Heltemes W. Houston
- 0. Rothberg OPo3 8907130185 890217 i t 7 -. 7 PDR REVGP NRCCRGR
_ j f..._ l V
MEETING 15e PDC NBC FILE CENTER COPY
I k
1 j.
p ISSUE IDENTIFICATION FOR CRGR AGENDA ITEM CRGR Meeting No. 158 - February 22, 1989 I
l Proposed Generic Letter on MOV Testing and Surveillance
-1.
CRGR considered an earlier version of this proposed Generic Letter at Meeting No. 148.
The Committee did not recommend approval at that time, but made a number of recommendations for improvements to be made to the package.
The Committee also indicated that the revised package should be brought back to CRGR for further review after revision to reflect CRGR comments / recommendations and discussions of MOV experience and
{
l problems at a planned meeting with NUMARC.
A copy of the Issue Sheet l
prepared for-that earlier review, is attached for the information of the members.
I Generally, the staff appears to have been responsive to the Committee's I
comments / recommendations at Meeting No. 148 with one notable exception.
l The Committee was critical of 'the overly conservative manner in which the high MOV failure rates indicated by the results of recent testing using new testing methods (e.g., MOVATS) had been applied by the staff in the
{
PRA analyses offered in support of this proposal. This threw into serious question the staff's conclusion that NUREG-1150 core melt frequencies are an order of magnitude higher than originally estimated, which in turn called into question the staff's very favorable estimates of risk / cost I
benefit associated with this proposal.
Specifically, the Committee seriously questioned whether it was correct in the staff's supporting analyses (a) to apply the new, higher M0V failure rates indicated by recent test results/ methods to all systems in the high pressure sequences examined, and (b) to give no credit for operator recovery actions.
The Committee's doubts on these points were serious enough, and the anticipated effort to review / revise those PRA-based analyses so extensive, that CRGR suggested the staff eliminate that portion of the package and try to'go forward on the basis of a deterministic evaluation / justification alone.
It does not appear that j
the staff has reacted or responded adequately to this very fundamental l
CRGR criticism of the original MOV package.
l 2.
The staff have not provided any revised estimates of overall costs or cost-benefit involved in implementing the proposed MOV test and j
surveillance requirements, to take into account (a) the significant
]
increase in the staff's estimate in the revised package of licensee t
burden hours required to implement the proposed new requirements (from 200 hrs to 2000 HOURS), (b) the prospect raised in the revised package of prototype testing required for some MOVs, or (c) the CRGR concerns, comments, and suggestions in Item 1. above.
It seems likely that the impact of these considerations on estimates of total costs involved will be very significant; and this could change drastically the very favorable cost-benefit picture presented in the original package.
(
y
- a -
I
\\
Issue Identification Sheet for-h
'CRGR Agenda Items - Meeting No. 148 October 12, 1988 P
'A.
Amendment to 10 CFR 50, Appendix J 1.
This~ review item seems straightforward; no real issues were ident-ified as a result of CRGR staff preliminary review. - The proposed I
amendment was reviewed by the Committee at the draft rule stage at-Meeting No. 126 in December 1987.
The final rule appears to be -
identical to the proposed Draft Rule reviewed earlier; so there should be no CRGR issues pending.
However, the staff received several comments on the draft rule that were rejected; this item was included on the. agenda for Meeting No. 148 in the event the Committee wanted to discuss the public comments.
The comments were included in the review package; and the staff will be prepared to discuss them at Meeting No. 148.
B.
Generic Letter on MOVs 1.
The MOV reliability issue was considered by CRGR earlier this year _at Meeting No. 133 (review of proposed NRC Bulletin 85-03, Supplement 1).
The Committee's conclusions and recommendations from that review are attached.
2.
The biggest potential issue at this stage in connection with the followup Generic Letter on MOVs proposed by the staff at this time, is the near order of-magnitude change in calculated CMF for the NUREG-1150 reference plant, Grand Gulf.
The Committee may wish to assure that the staff's new value was derived correctly.
In this context, relevant questions _would appear to be:
a.
Is the licensee aware of this new calculated value for the plant, and does the licensee agree that it is correct? Has the licensee had an opportunity to review and comment on the new calculation?
b.
Is the new CMF value based on MOV failure rate (s) reported to the staff in response to Bulletin 85-03, Supplement I? If so, how is this consistent with the information given for Grand Gulf in Enclosure 6 of the review package? Does Enclosure 6 need changing / updating; or does the licensee really believe the "zero inoperative valves" data summary given there for Grand Gulf?
c.
Why are non-safety related MOVs excluded from the scope of the proposed Generic Letter? Were non safety related MOVs consider-ed in the recalculation of the NUREG-1150 CMF values for Grand Gulf? If the MOV failure problem is as pervasive as indicated in the review package, wouldn't at least as high a failure rate
F T7
---~ -- --~
- - - - - - - - - - - - - - - - ~
-~
' - - ~ - - - -
~ - - - - -
- p e
4 -
be expected for non-safety related valves? And couldn't that
?
affect-significantly the rate of initiation of risk 'significant -
sequences, and thereby increase the calculated CMF even further?
d.
'In.the first paragraph of the transmittal letter and proposed Generic Letter, what is intended by the staff in defining the
~
scope as "all safety-related MOVs and all MOVs in safety-L_
related systems that might become mispositioned and affect system operability..."?
Doesn't the first category include the second? Should this be clarified by the staff?-
1 i
J i
l L
l
_mu--_-2.___--.-------
W
?
l
/
3-4 CONCLUSIONS / RECOMMENDATIONS The Committee discussed MOV adjustments and settings, mispositioning, or locking in place with respect to the affects on MOV performance and The consensus was that adjustable MOVs should be adjusted for reliability.
safe operation with the connotation that locking in position would offer assurance of proper positioning for HOVs that were not required to stroke for the system safety function.
Based on evidence from staff reviews of licensee submittals in response to NRC Bulletin 85-03 relative to differing plans by the 18 licensees about which MOVs were covered by the bulletin, the Committee concluded that the proposed bulletin supplement addressed a small set of MOVS (seven or less at a given plant) and that generic communication was needed to clarify the staff position.
The Committee recommended that the staff proceed to issue the proposed bulletin supplement, but rodify the current draft to indicate whether major equipment design changes (e.g., larger operator, larger motor, larger valve stem) necessary to accommodate the differential pressure from inadvertent MOV The bulletin itself should not require modification beyond the positioning.
However, the licensee should be required to submit a approved design base.
justification for continued operation in lieu of making equipment This JC0 should be reviewed by the NRC staff for plant modifications.
specific backfit determinations.
- -_ -____ - _