ML20072Q578

Forwards Amend Applications 134 & 118,Suppl 1 to Licenses NPF-10 & NPF-15 for Plant Units 2 & 3.Suppl 1 Revises Ref Proposed Change Number 431

ML20072Q578
Person / Time
Site:	San Onofre
Issue date:	09/06/1994
From:	Rosenblum R SOUTHERN CALIFORNIA EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20072Q580	List: ML20072Q578 ML20072Q587
References
NUDOCS 9409120121
Download: ML20072Q578 (3)

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Southern California Edison Company 23 PARKER STREET IRVIN E, C ALIFORNIA 92718 RICHARD M. ROSE N BLUM T E LE PHON E wa .- v September 6,1994 ->~..o U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen: ,

Subject:

Docket Nos. 50-361 and 50-362 Supplement 1 to Amendment Application Nos. 134 and 118 Automatic Removal of Low Pressurizer Pressure Trip Bypass San Onofre Nuclear Generating Station Units 2 and 3

Reference:

September 15, 1993, letter from Richard M. Rosenblum (SCE) to Document Control Desk (NRC),

Subject:

Docket Nos. 50-361 and 50-362, Amendment Application Nos. 134 and 118, Automatic Removal of Low Pressurizer Pressure Trip Bypass, San Onofre Nuclear Generating Station, Units 2 and 3 Provided as Enclosure 1 are Amendment Application Nos. 134 and 118, Supplement t 1, to Facility Operating Licenses NPF-10 and NPF-15 for the San Onofre Nuclear  !

Generating Station, Units 2 and 3, respectively. Supplement I revises the referenced Proposed Change Number (PCN)-431. This change is being requested to resolve inconsistencies associated with the Low Pressurizer Pressure (LPP) trip bypass in several Technical Specifications (TSs) and make the TSs consistent .

with each other. [

The existing TSs permit a manual bypass of the Reactor Trip and Safety Injection Actuation Signal (SIAS) on LPP below 400 psia. The TSs also require that this bypass be automatically removed above 400 psia. The instrument which automatically removes the bypass is also part of the manual bypass circuitry. .

This instrument's circuitry requires that following automatic removal of the LPP l trip bypass, the pressure be reduced an additional 75 psi (hysteresis) before it  !

will again permit manual bypass. Consequently, it is necessary to depressurize to approximately 325 psia to ensure the bypass feature will be enabled. At 325 t psia, there is- a risk of an undesired SIAS due to the very small margin (25 psi) i between the LPP trip (300 psia) and the SIAS bypass (325 psia). Therefore, a i higher bypass pressure is desired to preclude the potential for an undesired ,

SIAS.

Supplement I revises Note (2) of TS Table 2.2-1, Note (b) of Table 3.3-1, Note  :

(a) of Table 3.3-3, and Note (1) of Table 3.4-4 by 1) making the pressure i associated with the automatic removal of the Low Pressurizer Pressure (LPP) trip ,

bypass at a consistent value of "before pressurizer pressure exceeds 500 psia  !

(the corresponding bistable allowable value is s 472 psia)" and 2) rewording the Notes associated with the LPP trip to be consistent with each other. An ,

analysis of the LPP trip concludes that it is not required below 500 psia.

000047 I 9409120121 940906 PDR ADOCK 05000361 -

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Doctnent Cont rol Desk Additionally, Supplement I withdraws the request in PCN-431 to revise Technical Specifications 3/4.5.2, "ECCS Subsystems-Tavg Greater Than 350*F," and 3/4.5.3, "ECCS Subsystems-Tavg Less Than 350 F," and their associated Bases.

Enclosure 2 provides the changes to Table 3.3.1-1 Note (c), Table 3.3.5-1 Note (b), and the associated Bases in the Technical Specification Improvement Program (PCN-299) Technical Specifications to reflect the changes requested in PCN-431, Supplement 1.

If you would like additional information on this Technical Specification change request, please let me know.

Sincere 1y, j i, <

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Enclosures ,

i cc: L. J. Callan, Regional Administrator, NRC Region IV l A. B. Beach, Director, Division of Reactor Projects, Region IV l K. E. Perkins, Jr., Director, Walnut Creek Field Office, Region IV J. A. Sloan, NRC Senior Resident Inspector, San Onofre Units 1, 2, and 3 M. B. Fields, NRC Project Manager, San Onofre Units 2 and 3 H. Kocol, California Department of Health Services

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ENCLOSURE 1 i PCN-431, SUPPLEMENT 1 I

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