3F0990-04, Informs of Continuing Activities at Facility to Clearly Define & Resolve post-accident Hydrogen Control Issues. Concludes That Sys Fully Capable of Performing Intended Function

Informs of Continuing Activities at Facility to Clearly Define & Resolve post-accident Hydrogen Control Issues. Concludes That Sys Fully Capable of Performing Intended Function

ML20065E685
Person / Time
Site:	Crystal River
Issue date:	09/20/1990
From:	Beard P FLORIDA POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
RTR-NUREG-0578, RTR-NUREG-0737, RTR-NUREG-578, RTR-NUREG-737 3F0990-04, 3F990-4, IEB-79-01, IEB-79-1, NUDOCS 9010020261
Download: ML20065E685 (3)

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Crystal River Unit 3 Docket No. 50-302 j J

Septemoc~ 20, 1990 3F0990-04

.d; U. S. f;uclear Regulatory Commission Attention: Document Control Desk-  :

Washington, DC 20555  !

Subject:

. Post-accident Hydrogen Control, ,

Reference:

A. NRC to FPC letter dated-December 3, 1976.- l B. FPC to NRC letter dated December 15, 1980 C. FPC to NRC letter dated October 31, 1980

Dear Sir:

This letter is being provided to inform the NRC staff of the continuing activities i- at Florida Power Corporation (FPC) to clearly define -and resolve post-accident hydrogen control issues at Crystal River Unit 3.(CR-3).. These issues were discussedL -

in telephone conversations with the NRC' staff on August 16 and 17 1990.3 This' letter, o briefly describes how these: issues were: identified,-. provides a_.descriptionfof the -

issues, and the plans for corrective action; 'Each ; issue and the- associated corrective actions are discussed separately. '

BACKbROUND As part of the on-going Environmental Qualification (EQ) Enhancement ^ Program,' an-  !

internal question arose regarding the need to environmentally qualify equipment in - .

the Post-accident Hydrogen Purge System at CR3.. . While researching this question, FPC discovered other potential' issues' relating to' the adequacyJ of the design'of this ,j i system. Some of these issues 3 were discussed with the NRC staff inL telephone  ;

conversations on August 16 and 17; 'Since that- time, FPC has' taken appropriate  ;

g corrective actions' to assure the system meets the applicable- design andL licensing, requirements: (the original licensing basis, NUREG-0578, NUREG-0737,10 CFR' 50.44, ,

and 10 CFR 50.49). l 1

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l POST OFFICE BOX 219

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. U. S. Nuclear Regulatory Commission 3F0990-04 '

g Page 2 Oriainal Licensina Basis  :

l. An evaluation was performed to verify conformance to the original' licensing basis = 1 and 10 CFR 50.44. A concern about the ability of the design to meet the requirements l 41, 42, and 43 was identified. This concern was.. '

of General resolved Design through Criteria a review of(GDC)inal orig license correspondence. It was determined that the NRC' staff specifically reviewed the original system design and determined it to .

be in conformance with We s 41, 42, and 43. This determination is documented;in- 'l the Safety Evaluation Report of:the Operating License (Reference A) for CR-3 and states: t "We have reviewed the combustible gas control ~ systems for conformance to GDC Nos. 41, 42, and 43 and Regulatory Guide 1.7.

We find them in conformance with these criteria and conclude q that -the systems are acceptable." ,

FPC has also reveewed the current system design to assure the modifications made to the system were adequate, and to assure that the oriainal design requirements are ,

still met. As a result of that review,-it was determined that the purge . exhaust flow control valve and flow indication was redundant in the original design; This i redundancy has been inadvertently eliminated in subsequent plant modifications.

FPC will evaluate modifying the system design to restore this redundancy. This evaluation will be completed and the NRC notified of results before December 31, 1990.

NVREG-0578 and NUREG-0737 The procedure for operttion of the Post-accident Hydrogen Purge System implements a lower degree of redundancy of containment penetrations than . implied by NUREJ-0578 and NUREG-0737. The procedure at CR-3 for post accident hydrogen purging includes the provisions to utilize a single containment: penetration for. repressurization supply and redundant penetrations for hydrogen purge- exhaust, t FPC now recognizes.

that NUREG-0578 and NUREG-0737 intended i hat there be redundancy for the l penetrations for both repressurization supply ,and purge exhaust. = Redundant l penetrations are available for repressurization " supply, but their use is not reflected in plant procedures, and a minor modification would'be required to adapt the compressor connection for the redundant penetrations. . As corrective action, FPC q will provide one or .more additional containment penetrations for use -in repressurization to achieve theLredundancy implied by NVREG-0578 and NUREG-0737 (i.e., so designate; provide means for compressor connection; and proceduralize).

These actions will be completed.before December 31', 1930.

Dedicated Hydroaen Purae Filter Corp 115 mt.

FPC has not formally notifies 4 the NRC staff of a change to a related voluntary commitment. In a letter t.o the NRC discussing NUREG-0737 implementation (Reference B), FPC committed to a modification to molement the existing purge filter and piping with a dedicated hydrogen pu'ge unit. The added purge unit would have been designed to allow contaMnated f0ter change-out and to facilitate condensation drainage back to the containment. Subsequent to that submittal, it was determined i

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9 U. S. Nuclear. Regulatory Commission 3F0990-04 Page 3 the advantages of the dedicated hydrogen purge filter did not justify the high cost.

Consequently, the modification was cancelled.

10 CFR 50.49 FPC had committed to include-the Post Accident Hydrogen Purge System equipment in -

CA 3's EQ Program in a response (Reference C) to IE Bulletin 79-018. However, this

'tas not yet been done. Most, but not all, of the equipment is qualifiable without modification. This equipment' includes the containment isolation valves, .the purge '

exhaust flow transmitter, and the purge exhaust fans. FPC is now pursuing-qualification of that equipment which is expected to be. completed by December 1,.

1990. In additia, a modification has been installed to allow operation of the system without the solenoid valves on the purge exhaust dampers which are unqualifiable.  !

On August 20, 1990, FPC confirmed that those unqualifiable solenoid valves were  :

required for system operation. The system was declared inoperable and the Action Statement for Technical Specification 3.6.4.2 was entered. This Action Statement.  ;

requires that the system be restored to operable status within 30 days. Corrective'  ;

actions included the modification to eliminate the reliance on.the unqualifiable solenoids, modification to the purge procedure to reflect the modification, and reverification that all other equipment was qualifiable. Following completion of -

these corrective actions, the Technical Specification Action State.nent was exited on September 13, 1990.

CONCLUSION In conclusion, while deviations from NRC guidance have been~ identified in the Post-accident Hydrogen Purge System design, the system is fully capable of performing its intended function. FPC will keep the NRC informed of the status of corrective actions. In addition, the Final. Safety Analysis Report will be updated to better describe the system and its function.

i Sincerely,

h. H. Beard, Jr.

Senior Vice President Nuclear Operations PMB:AEF q l xc: Regional Administrator, Region II Senior Resident Inspector .i l

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