ML20206P405

Responds to Re Request of TS Interpretation. Instrumentation with Battery Backup,But Lacking DG Backup Cannot Be Excluded from Provisions of Action B.2

ML20206P405
Person / Time
Site:	San Onofre
Issue date:	05/12/1999
From:	Raghavan L NRC (Affiliation Not Assigned)
To:	Ray H SOUTHERN CALIFORNIA EDISON CO.
References
TAC-MA0232, TAC-MA0233, TAC-MA232, TAC-MA233, NUDOCS 9905180224
Download: ML20206P405 (4)

Text

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NUCLEAR REGULATOR 1f COMMISSION WASHINGTON. D.C. - "1 l May 12, 1999 Mr. Harold B. Ray i

Executive Vice President  !

Southem California Edison Company San Onofre Nuclear Generating Station P. O. Box 128 San Clemente, CA 92674-0128

SUBJECT:

TECHNICAL SPECIFICATION INTERPRETATION (TAC NOS. MA0232 AND MA0233)

Dear Mr. Ray:

In a letter dated December 5,1997, Southem Californic Edison (SCE) requested an interpretation of San Onofre Units 2 and 3 Technical Specification (TS) 3.8.1, Action B.2. l TS 3.8.1, Action B.2, states in part: " Declare required feature (s) supported by the inoperable l DG inoperable when its redundant required feature (s) is inoperable."

In your letter you provided your interpretation of the specific features to which this Action applies. Your interpretation is that the specific features to which this action applies are those critical features that require 1E power from one of the 4kV buses to perform their safety ~

function in the event of a loss of offsite power. Systems or components that fall in their safe '

position on a loss of power do not require power, or their failure does not result in a complete loss of safety function and are not covered by TS 3.8.1, Action B.2.

TS 3.8.1, Action B.2, is the required action to be taken on the loss of an emergency diesel generator (EDG), Required Action B.2 is intended to ensure that a loss of offsite power during ihn period that an EDG is inoperable does not result in a complete loss of safety function of com.al systems. The features that are included in Action B.2 are those redundant systems or components that require electrical power to perform their safety function. Therefore, the staff agrees that a system or component that falls in its safe position on a loss of electrical power or does not require electrical power to perform its safety function is not covered by TS 3.8.1, Action B.2.

In addition, you stated that systems or components whose failure does not result in a complete j

' loss of safety function are not covered by TS 3.8.1, Action B.2. You cite vital bus O instrumentation that is powered by a battery-backed power source as an example.

l The staff's position is that instrumentation, in general, is covered by TS 3.8.1, Action B.2. With I a diesel generator inoperable, a loss of offsite power would result in only the battery powering the instrumentation. A battery, by itself, has only limited capability and will cease to power the instrumentation after some period of time. This is especially true of the post accident 0D\ ll monitoring instrumentation which must be available for an extended period of time. Therefore, instrumentation with a battery backup but lacking a diesel ger erator backup cannot be excluded I from the provisions of Action B.2. Note this position assumes a long-term 9905180224 990512 PDR ADOCK 03000361 PDR

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4' H. Ray requirement for instrumentation. For situations where the instrumentation function is only required immediately following the design-basis event, battery backup may be appropriate and the instrumentation may be excluded from the provisions of Action B.2.

Also, you listed the systems and their associated specifications that you believe are within the scope of TS 3.8.1 Action B.2. The staff's position is that a TS interpretation or a change to the TS Bases is not the appropriate place to exclude systems or components from the applicability i of the TS. The Bases are provided to explain to the extent possible what is already in the TS j and not to exclude equipment from the requirements of TS. If equipment is to be excluded '

from the requirements of TS, the appropriate place to do so would be in TS, not the Bases.

TS interpretations are useful for the licensee to understand and correctly implement TS ,

requirements; however, TS interpretations cannot change the meaning or intent of the TS or exclude equipment from the requirements of TS. {

j If you have any questions regarding this TS interpretation, please call me at 301-415-1471 Sincerely,

/s/

L. Raghavan, Senior Project Manager, Section 2 Project Directorate IV and Decommissioning Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-361 and 50-362 cc: See next page DISTRIBUTION Docket File OGC PUBLIC ACRS PDI-2 Reading WBeckner JZwolinski/SBlack LSmith, RGN IV SDembek LRaghavan CJamerson

• Input provided by memo I OFFICE PDIV-2/PM PDIV-D/LA x RTSB/8C* PDIV-2/SfL NAME LRaghavan:rb MCJ$m f WBeckner SDe DATE 5' / P/99 I /l}/99 04/04/99 [/ 99 OFFICIAL RECORD COPY l DOCUMENT NAME: G:\ SONGS \LTR0232.WPD i I

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.9 H. Ray requirement for instrumentation. For situations where the instrumentation function is only required immediately following the design-basis event, battery backup may be appropriate and the instrumentation may be excluded from the provisions of Action B.2.  ;

I Also, you listed the systems and their associated specifications that you believe are within the i scope of TS 3.8.1 Action B.2. The staff's position is that a TS interpretation or a change to the l TS Bases is not the appropriate place to exclude systems or components from the applicability of the TS. The Bases are provided to explain to the extent possible what is already in the TS and not to exclude equipment from the requirements of TS. If equipment is to be excluded from the requirements of TS, the appropriate place to do so would be in TS, not the Bases.

TS Interpretations are useful for the licensee to understand and correctly implement TS requirements; however, TS interpretations cannot change the meaning or intent of the TS or exclude equipment from the requirements of TS.

If you have any questions regarding this TS interpretation, please call me at 301-415-1471 Sincerely, A -,

L. Raghavan, Senior Project Manager, Section 2 I Project Directorate IV and Decommissioning Division of Licensing Project Management .

Office of Nuclear Reactor Regulation l Docket Nos. 50-361 and 50 362 cc: See next page

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I San Onofre Nuclear Generating Station, Units 2 and 3 cc' Mr. R. W. Krieger, Vice President ~ Resident inspector / San Onofre NPS Southem Califomia Edison Company c/o U.S. Nuclear Regulatory Commission San Onofre Nuclear Generating Station Post Office Box 4329 P. O. Box 128 San Clemente, Califomia 92674

- San Clemente, Califomia 92674-0128 Mayor Chairman, Board of Supervisors City of San Clemente County of San Diego 100 Avenida Presidio 1600 Pacific Highway, Room 335 San Clemente, Califomia 92672 San Diego, Califomia 92101 Mr. Dwight E. Nunn, Vice President Alan R. Watts, Esq. Southem Califomia Edison Company Woodruff, Spradlin & Smart San Onofre Nuclear Generating Station 701 S. Parker St. No. 7000 P.O. Box 128 Orange, Califomia 92668-4702 San Clemente, Califomia 92674-0128 Mr. Shenuin Harris Resource Project Manager Public Utilities Department City of Riverside 3900 Main Street Riverside, Califomia 92522 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavilion 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011 8064 Mr. Michael Olson i San Onofre Liaison i

. San Diego Gas & Electric Company ,

P.O. Box 1831 San Diego, Califomia _92112-4150 1 Mr. Steve Hsu Radiologic Health Branch

. State Department of Health Services ,

Post Office Box 942732 Sacramento, Califomia 94234

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