3F0792-03, Responds to NRC Re Violations Noted in Insp Rept 50-302/92-11.Corrective Actions:Valve EFV-14 & Associated Motor Operator Replaced W/Different Design.Similar Valves EFV-11,32 & 33 Also Modified

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Responds to NRC Re Violations Noted in Insp Rept 50-302/92-11.Corrective Actions:Valve EFV-14 & Associated Motor Operator Replaced W/Different Design.Similar Valves EFV-11,32 & 33 Also Modified
ML20101Q251
Person / Time
Site: Crystal River Duke Energy icon.png
Issue date: 07/09/1992
From: Beard P
FLORIDA POWER CORP.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
3F0792-03, 3F792-3, NUDOCS 9207140213
Download: ML20101Q251 (6)


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  • g Power C 0 R P O R AliO N crystal River unit 3 Docket No. 50-302 July 9, 1992 3F0792-03 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555'

Reference:

1) NRC letter to FPC dated June 3, 1592c Notice of Violation and= Enforcement Conference Summary - Inspection Report 92-11

Dear Sir:

4 Florida Power Corporation (FPC) provides Attachment Isas our response toTthe >

Notice of- Violation (NOV). Attachment (II prm ! des our responsetto your-request for additional .information.

FPC notes that the NR_C . staff has generally 1 agreed with our-assessment of the safety: significance of this event. Thus, Severity _LeveleIV can be viewed as'a reasonable compromise. However, FPC's positionLat;the Enforcement Conference ^

was that,' based on our understanding of Generic letter--(GL) 91pl8, we had ,

complied with-10CFR50, Appendix B, Criterion XVI. The NOV.provides little elarification.in this regard. .It is:our understanding lthat: ti.' basic; concern -

is that the formal' calculation revision:was~not completed prior.to restart.-

That would imply:that documented engineering:judgmentLis.not anfappropriate q resolution of a condition adverse to quality.1 lIt:would be .very:hel)ful to; gain a more complete understanding of the NRC Lstaff's position Lon' t11s issue.

Nevertheless, we'have taken actionsEsufficient,to ccrrect the1 problems'withL valve EFV-14 and related motor-operated valve- (MOV)- concerns; - We have

' discussed this with appropriate members of the NRC staff and wantito R

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' GENERAL OFFICE: 3201 Thirty fourth Street South

  • P.O. Box 14042 + -_ St. Petersburg, F. lorica 33733 + ; (813) 866-5151:

9207140213:920709 A Florida Progress Company L l PDR ADOCK 05000302

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U. S. Nuclear Regulatory Commission 3F0792:03

Page 2 emphasize that our intent is not to prolong the discussion over the event in question. Rather, we are seeking additional clarification that we_ believe will benefit FPC and other licensees.

Please note also that, due to the above mentioned considerations, FPC has taken somewhat more tine to develop our response to this NOV. A one week celay was discussed and approved by telecon (FPC's E. E, Froats to NRC's Region'!! R. P. Schin) on July 2, 1992.

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Sincerely, i

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, .M Beard, Jr.

. Senior Vice President Nuclea' 07?-ations

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, Enclosure xc: Regional Administrator, Region 11 NRR Project Manager-

. Senior Resident Inspector

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ATTACHMENT I

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Page 1 of 2 I-l FLORIDA POWER CORPORATION

, NRC INSPECTION REPORT NO. 50-302/92-11 REPLY TO NOTICE OF VIOLATION'-

VIOLATION 50-302/92-11-01 1

? 10 CFR Part_50, Appendix-B, Criterion XVI, Corrective Actions, requires in i part, that measures be established to- assure that conditions adverse to .

i quality, such as failures, malfunctions, deficiencies, deviations, defective j material and equipment, and nonconformances are promptly identified and j corrected.

l Contrary to the above, prompt corrective action related to the failure of i Emergency Feedwater Valve EFV-14 to fully close during testing on October-13, j 1991, was not completed prior to restart of the reactor on November 25,~1991.

1 The operability determination made on November 17, 1991, was not based on--

objective evidence, but' rather on assumed conservatism-in the differential l pressure calculation for EFV-14.

i ADMISSION OR_ DENIAL OF THE AIMGED VIOLATIOJ ,

I Florida Power Corporation (FPC) agi;es with the general summary of the evet- 's i_ associated with the failure of:EFV-14 in October 1991 contained in the 4- violation ar.d accepts the' violation.. However,.as stated at the Enforcement

{: Conference, FPC does not agree that these events constitute a' violation of 10' -

CFR -50, Appendix B,. Criterion XVI.

! BASIS FOR FPC POSITI.0J l

i folloning the test failure.on October 13,.1991,;FPC determined that.

! improvements .in the maintenarce condition of the . valve operator would be reasonably expected to correct the problem. This;was based o_n our past.

experience with si
nilar components. Furtiier, FPC was able:to upgrade'the -

i torque capacity (and related: torque switch settings).of.:the. operator during i 'the outage which enhanced its' capability. -'A retest-was scheduled to occur-

! during; plant startup when system conditions _could'be establishedEto'confirmt

the adequacy of-the correctiveLactions. That retest failed. EWhen evaluatingi the. retest failure,, it was determined that theLcalculation on-which the- ",

, J j<' maximum-differential pressure value'for.the retest;was based, was in error.

The' projected /correctF test' pressure was determined to.be11ess than that for which the' valve had' already been successfully": tested. in the past. _ Following a restart,-1this was confirmed 11n the formaltcalculationLrevision. -:During the; development of_a subsequent: test procedure,-an assumption was._ identified as? y

being consistent with our past: experience but>potentially1non-conservative. l
_ Efforts to confirm _or__ refute this assump_t_ ion were not_-. conclusive. .FPC decided i to utilize a worst-case value calculated using that more
conservative ,

assumption.- The resulting~ projected de' sign-pressure was higher than that! l

, which the valve had been able to pass.. i H

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  • ATTACHMENT I  ;

Page 2 of 2  !

The violation notes that the decision to restart was based upon "... assumed conservatism..."_not "... objective evidence." The conservatism was not assumed. The preponderance of available information clearly supported the ,

conclusion that the calculated differential pressure was erroneously high, '

This was explicitly enumerated in the documentation provided to Operations through Licensing. Further, FPC notes that criterion XVI does not limit objective evidence to retesting or formal calculations. Many conditions 1 adverse to quality are identified and completely resolved without in situ testing or formal calculations. Had we retested at the best estimate of the i design pressure at that time there is every reason to believe that it would have passed again. In hindsight, it may have been more' appropriate to have completed the formal calculation revision prior to restart. Nevertheless, had we done so, we would have almost certainly concluded, as we did a few weeks later, that- the appropriate test pressure was less than that already successfully demonstrated. We do agree that had the expected new design pressure been higher than the successful test a formal calculation and retest would have been clearly _ warranted.

REASON FOR THE VIOLATION FPC did not recognize that documented engineering judgmeat was an insufficient basis for resolving a condition adverse to quality.

CORRECTIVE ACTION

, Valve EFV-14 and its associated motor operator were replaced with a different design. Similar valves EFV-11, 32,. and 33 were also modified. EFV-ll and its associated motor operator were replaced with a different design,,EFV-32 and 33 motor operators were modified to-increase thrust. All four valves were tested to the worst case differential pressure calculated using the conservative assumptions. All four valves passed the test.

CORRECTIVE ACTION TO PRt CNT FURTHER VIOLATIONS The lessons learned from this testing,~ as well as similar testing at other nuclear facilities, will be factored into FPC's GL 89-10 MOV program.

FPC is currently enhancing our guidance on operability determination. This action requires clarification of the NRC staff position on engineering-

judgment.

DATE OF FULL COMPLIANCE EFV-II,14, 32, and 33 successfully passed the differential pressure test on June 27, 1992.

The lessons learned will be incorporated into our MOV program by September 30, 1992.

Enhanced guidance on operability vill be provided 30 days after receipt of NRC clarification ca engineering judgment.

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- ATTACHMENT 11 l

Page 1 of 2 l FLORIDA POWER CORPORATION NRC INSPECTION REPORT NO. 50-302/92-11 REPLY TO REQUESTS FOR ADDITIONAL INFORMATION liEASURES ESTA1LISHED TO ASSURE PRWPT CORRECTION OF SQCJLQELCLDiclES f
1) FPC has considerable guidance in place associated with implementing the requirements of Appendix B (including Criterion XV and y'll). F Pr.

has reduced the number of Corrective Action Programs as a result of our own assessments as well as encouragement from the NRC, We believe the :esulting syctems more consistently meet the requireh.ents and intent of Appendix B.

2) FPC has recently developed and issued internal guidance associated with MOV calculational and test failures. It assures that yAltd test failures *esult in the H0V being considered INOPERABLE. Although not required by GL 89-10, FPC alto requires immediate corr'.setive actions for MOVs where the best design information we have callable indicates the valve is not capable of fulfilling its esit,n function ever, though no test has been failed.
3) FPC is revising its overall ada'nistrative controls associated with OPERABILITY assessments in accordance d th the guidance of GL 91-18 along with those being developed as oart of the Improved Technical Specifications. The lessons learned from this experience will oc factored into these as well. This guidance will require OPERABILITY determinations to be clearly documented and based on the best information available at that time, as well as the expectation that subsequent information will support the determination made.

Nevertheless, as happened in this case, thare'will always be situations where future information or events render such date minationr invalid, in these cases, a reevaluation of OPERABILITY is required.

JNPLEMENTATION OF CONTROLS FOR DETERMINING REPORTABILITY While FPC understands why the concern was stated regarding reportability, FPC does not completely agree with the characterization that the information available on April 24 was the same as that available on April 28. The Problem Report (our form for handling conditions adverse.to quality and initiating reportability assessments) was reevaluated for reportability on April ?.8 when the revised calculation was completed arid verified.. The decision to take interim actnns was takrn based on the changing information as noted above.

As noted ir. GL "' 18, the primary concern must always be to take prompt actions to assurt: safety with subsequent actions following as soon thereafter  :

as possible. i i

    • ATTACHMENT II Page 2 of 2 As noted at the Enforcement Confererr,c, FPC did inform our Project Manager and Resident inspectors on April 27, even though the formal reporting as required by 10 CFR 50.72 was delayed an additional day pending completion of the formal calculation. It should also be noted that the NRC H0V Inspection Report (50-302/92-01) reflected the fact that the calculations were not yet complete. In the past, FPC has reported some situations prior to completion of a formal verification on at least a preliminary basis. The enhanced administrative controls outlined above will ' aid in developing more consistency in these

( matters. We also understand that the NRC is revising NUREG-1022 (the primary interpretation document astociated with 10 CFR 50.72)'. . It may be oppropriate to address such situation: in the NUREG.

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