ML20236S141

Requests Schedular Relief from Commitment to Install Open, failed-closed,direct-acting Solenoid Valve on All Drywell Instrument Air Headers Penetrating Primary Containment,In Order to Install Continuous Nitrogen Supply Sys

ML20236S141
Person / Time
Site:	Brunswick
Issue date:	11/20/1987
From:	Richey R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
GL-84-09, GL-84-9, NLS-87-263, NUDOCS 8711240248
Download: ML20236S141 (3)

Text

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!, COMBUMA M O M M M P. O Box 1561

• Raleigh, N. C. 27602 o

m _ NOV 20 E6T SERIAL: NLS-87-2 63

.d R. B. RfCHEY, Manager I y, , Ucensing & Nuclear .

' Fuel Department l

I United' States Nuclear ~ Regulatory Commission j ATTENTION: Document Control Desk 1 Washington, DC- 20555 j

BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 j REQUEST.FOR-CONCURRENCE WITH ALTERNATE COMPLIANCE j

.WITH PROVISIONS OF GENERIC LETTER 84-09 i l

References:

1. NRC letter from E. D. Sylvester dated October 30, 1986,

" Hydrogen Recombiner Capability"

-2.- CP&L' letter from S. R. Zimmerman dated December 19, 1986

" Hydrogen Recombiner Capability"

3. CP&L letter from A. B. Cutter dated March 27, 1987 m: " Request for License' Amendment - Nitrogen Backup System" Gentlemen:

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• In1 response to a Safety Evaluation Report (SER) issued I

- October 30, 1986, ( Reference 1) Carolina Power & Light Company

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.*. (CP&L) committed to five actions.to demonstrate compliance with [

Generic LetterL84-09 for removal of potential oxygen sources from l

primary containment (Reference 2). The Brunswick Plant has j s completed these actions with the exception of installation of an additional normally'open, fail-closed, direct-acting solenoid i valve on each drywell instrument air header' penetrating the '

primaryicontainment. As agreed upon with the Staff (Reference 3, page 1), these valves were to be installed during the upcoming refueling outages for each unit (BSEP-1 Reload 6, scheduled to lbegin October 1988 and BSEP-2 Reload 7, scheduled to begin January 1988).

The Company has previously installed a nitrogen back-up supply system for the drywell instrument air headers. During normal operation, the plant instrument air system provides the pneumatic gas supply (atmospheric air) for the drywell instrument air headers. Upon receipt of a loss-of-coolant-accident signal, the instrument air supply is isolated and the nitrogen back-up system

' becomes the. pneumatic gas source for the drywell instrument air F headers supplying the automatic depressurization valves and

. suppression pool to reactor' building vacuum breaker valves.

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• P -Document. Control Desk NLS-87-263 [ Page 2 The Company has conducted several preliminary engineering studies over the past two years. These studies developed engineering recommendations to solve system or equipment problems on a priority basis relative to safety, ALARA, plant availability /

reliability,' maintenance' requirements, and ease of plant 1 operations.

One recent study reviewed our nitrogen systems and provided recommendations on ways.to minimize nitrogen usage. The study recommended installing a nitrogen pneumatic system for the "

drywell based on technical and economic merit. The continuous nitrogen supply system would consist of a 150 psig storage tank, ambient vaporizer,-and a pressure control valve. The continuous nitrogen supply system.would replace the present drywell

instrument air system during normal operation. The currently installed nitrogen back-up system would remain available in the event of loss-of-coolant-accident.

A continuous nitrogen supply system would eliminate the need to rely on an automatic system to isolate the drywell instrument air headers in the event of a header rupture prior to, or coincident with, a loss-of-coolant accident. Such a system would provide an  ;

enhanced method of addressing Generic Letter 84-09 concerns regarding potential sources of oxygen to the inerted drywell

. atmosphere.

As noted above, the Company previously committed to install an additional normally open, fail-closed, direct-acting solenoid valve on'each drywell instrument air header penetrating the primary containment. These modifications were to be installed during~the upcoming BSEP-2 Reload 7 outage (scheduled to begin January 1988) and the BSEP-1 Reload 6 outage (scheduled to begin October 1988). If.a continuous nitrogen supply system were

' installed, installation of an additional automatic isolation valve'on each drywell instrument air header would become unnecessary. Instead of completing installation of these additional automatic isolation valves of each drywell instrument air ~ header, the Company proposes to complete engineering and procurement for, and installation of, the continuous nitrogen supply system described above.

Based on the recently completed study and its recommendations, CP&L requests schedular relief from the previous USEP-1 and i BSEP-2. commitment in order to provide adequate time to design, j procure, install, and test a continuous nitrogen supply system on i both BSEP-1 and BSEP-2. The BSEP-1 system will be operational i

2. months following completion of the BSEP-1 Reload 6 outage l scheduled to begin October 1988 and the BSEP-2 system will be I operational 2 months following completion of the BSEP-2 Reload 8 {

outage scheduled to begin September 1989. The 2 month post-outage period is needed to complete final system testing and  ;

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.'NLS-87-263 /lPage ~.

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.., :evaluatefthe71mpact'of the' system.on drywell'inerting activities.

' 1  : This-cannotfbe: accomplished duringithe. outage.. Due tothe.need

-to-' finalize'BSEP-2' refueling. outage Work activities, your

,  : concurrence:with:this schedular relief.is requested by M ., , ' December 18, .~.- 19 8 7 ..

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Fleasefrefer. questions'regarding'this matter to Mr. Sherwood R.

i*'t 'Zimmerman.at (919)=836-6242.

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Yours very truly,

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R. B. Richey 4 Y

[ lEKN/ekn' ' (N2 SYS . DOC) '

cc:'.-Dr..J.INelson Grace  ;

N:'. 'Mr. L gH.-.Ruland A .Mr..E.,D..Sylvester

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