ML20212D275

Discusses Actions & Responses to NRC 861030 SER Re Acceptable Approach to Remove Potential Oxygen Sources from Primary Containment,Per Generic Ltr 84-09

ML20212D275
Person / Time
Site:	Brunswick
Issue date:	12/19/1986
From:	Zimmerman S CAROLINA POWER & LIGHT CO.
To:	Muller D Office of Nuclear Reactor Regulation
References
GL-84-09, GL-84-9, NLS-86-468, NUDOCS 8612310332
Download: ML20212D275 (3)

Text

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CD&L Carolina Power & Light Company i DEC 191986 SERIAL: NLS-36-468 Directer of Nuclear Reactor Regulation Attention: Mr. Dan Muller BWR Project Directorate #2 Division of BWR Licensing United States Nuclear Regulatory Commission ,

Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 _

DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 HYDROGEN RECOMBINER CAPABILITY

Dear Sir:

in a Safety Evaluation Report (SER) dated October 30,1986, the NRC informed Carolina Power & Light Company that an acceptable approach to demonstrate compliance with =

the guidance of Generic Letter 84-09 to remove all potential oxygen sources from primary containment would be to commit to five actions. Each action and the CP&L response is listed below:

1. Modify the non-essential instrument air system to provide automatic isolation upon receipt of the containment isolation signal assuming a concurrent single active failure.

CP&L Respense:

The nitrogen backup system design included installation of a normally open, fait closed, direct acting solenoid valve in each instrument air header penetrating primary containment. The valve will go to the closed position on receipt of a LOCA signal, thus satisfying the requirements of item No.1.

The valve also has an override function enabling the operator to reopen the valve with a LOCA si;fal received. CP&L intends to leave the override function on the valve based on response to item No. 5.

2. Verify that the essential nitrogen supply to the instrument system is a safety grade system and automatically supplies the instrument system upon receipt of the containment isolation signal.

CP&L Response:

The nitrogen backup system on 'Jr.it 2 is designkd as a seismic, environmentally qualified, Q-list system consistlng of two redundant divisions. Each division is isolated from the instrument air system by a normally closed, fail open, direct acting solenoid valve. The valve opens on

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Director cf Nucl:ar Rractor Regulation NLS-86-468 / pag 2 2 signal. Receipt of either signal allows the backup system to maintain pneumatic supply to the long-term, safety-related pneumatic loads. The system installed on Unit 1 is of the same design as that of Unit 2, except missing the' solenoid valve. The solenoid valve is to be installed in the Unit 1 outage scheduled for February 1987.

3. Provide testing and surveillance Technical Specifications for the essential nitrogen supply system.

CP&L Response:

Carolina Power & Light Company has reviewed the recommendation for testing and surveillance Technical Specifications for the essential nitrogen supply system. It is not clear at this time what an appropriate scope and content of those Technical Specifications would be. Therefore, CP&l, will schedule a meeting with the NRC to discuss the appropriateness and basis for the Technical Specification requirements.

4. Provide Technical Specifications for the essential nitrogen supply system that limit the condition for operation upon the loss of redundancy and the loss of the system.

CP&L Response:

As stated in response to Item No. 3, the basis and appropriate technical requirements for such Technical Specifications is unclear. To discuss this issue, CP&L intends to schedule a meeting with the NRC staff.

5. Verify that the plant operating procedures were reviewed for consistency with the above requirements and that all differences were corrected in accordance with these changes. Furthermore, remove all procedures that advocate supplying air into the containment after receipt of the containment isolation signal. -

CP&L Response:

Plant operating procedures were revised after installation of the nitrogen backup system and reflect the operating requirements of the installed system.

Procedures to ensure compliance with the specifications noted in 3 and 4 above will be developed during establishment of these specifications.

The BSEP operating procedures (developed in accordance with the BWR Owners' Group Emergency Procedure Guidelines) allow the restoration of instrument air to primary containment in response to two emergency procedures. Air is restored to allow the main steam isolation valves to be opened, allowing the main condenser to act as a heat sink. The emergency procedures affected are Emergency Depressurization and ATWS.

BSEP contends that these two conditions warrant the reintroduction of instrument air to primary containment based om

a. The ATWS condition does not reflect the LOCA events requiring the isolation of oxygen sources to the primary containment.

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• Direct'or cf Nucliar Ructor Regulation NLS-86-468 / pag 3 3

b. The Emergency Depressurization condition reflects a situation where the need to operate plant equipment outweighs the risk from momentary reintroduction of air to primary containment.

c. These actions are in accordance with the BWR Owners' Group Emergency Procedure Guidelines.

Please refer any further questions regarding this submittal to Mr. Stephen D. Floyd at (919) 836-6901.

Yours very truly,

. ,., s

(/k/Ra<~-

5 .Zim erman nager Nuclear Licensing Section BAT /bmc (5090 BAT) cc: Mr. W. H. Ruland (NRC-BNP)

Dr. 3. Nelson Grace (NRC-Ril)

Mr. E. Sylvester (NRC)

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