ML19320D160

Responds to NRC 791226 Ltr Re Violation Noted in IE Insp Rept 50-322/79-07.Corrective Action:Independent Analysis Performed to Ensure Prevention of Reactor Shutdown or Decay Heat Removal.Takes Exception to Insp Finding

ML19320D160
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	04/16/1980
From:	Novarro J LONG ISLAND LIGHTING CO.
To:	Robert Carlson NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19320D155	List: ML19320D160
References
SNRC-471, NUDOCS 8007210040
Download: ML19320D160 (3)

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P.O. BOX 618, NORTH COUNTRY ROAD . WADING RIVER. N.Y.11792 April 16, 1980 SNRC-471 Mr. Robert T. Carlson, Chief Reactor Construction and Engineering Support Branch

• U. S. Nuclear Regulatory Commission, Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406 NRC Inspection No. 79-07 Raceway / Cable Separation Shoreham Nuclear Power Station - Unit 1 Docket No. 50-322

Dear Mr. Carlson:

As part of the design and construction efforts undertaken on the Shoreham project, an independent separation analysis was performed which provides one means of ensuring that no single, credible event will be capable of disabling sufficient equipment to prevent reactor shutdown or decay heat removal. The analytical approach was developed in response to generic NRC concerns with the adequacy of fire protection in nuclear power plants. In addition, the analysis is being used as an engineering and construction check of routed class IE cable in the reactor building. It is a direct application.of the NT.C's " defense-in-depth" concept, based on criteria which have been conserva-tively applied to Shoreham. The analysis demonstrates that concurrent with the loss of offsite power and assuming loss of all componenes in a given area, hot and cold shutdown can be accomplished with limited manual operations using only safety-related systems and equipment.

The analysis, as applied to cable separation, is based on a shutdown model developed for use in assessing the impact of the assumption that operabilitv of all components associated with a given area is lost. It establishes affected areas taking into consideration the reactor building arrangement, identifies all class IE cables and their respective safety related components associated with the area, and assumes that the components are lost. The analysis constitutes a detailed, area-by-area review of the reactor building.

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e Mr. Robert T. Carlson April 16, 1980  !

Re: NRC-Inspection No. 79-07 Page 2 Specifically, each elevation of the secondary containment is i divided into-eight 45' segments. Upon completion of the analysis

of all segments of each elevation, each 45' segment is rotated 22.5*and the analysis is repeated to ensure that no particularly ,

sensitive interface boundaries exist. '

4 The. approach. utilizes a computer program to compare raceway

, location-(manually derived) with raceway cables (computer list), .resulting in a listing of class IE cables vs. area.

! This information is then re-entered into the computer, along

.with a tabulation of shutdown components vs. cables, in order to generate.a list of shutdown components vs. area. This approach was utilized because it eliminated the need to postulate a failure mechanism.and simultaneously demonstrated that multiple shutdown capabilities are inherent in the Shoreham design.. This approach has been used to demonstrate the adequacy of cable separation on operating units, and it is being used extensively in the Shoreham design and construction effort.

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' Formal completion of the analysis will coincide with completion of the installation of all class IE cable and its associated

equipment. At that time, an "as-built" review will be performed

to ensure the validity of the inputs to the analysis, as well

'as to check the engineering and construction efforts.

The analysis and backup material are available for review and verification at the site. We believe that this effort constitutes a major, independent control of design and construction activities

on the site. For this reason, we take exception to the inspection j finding that the conditions identified and reported (NRC Inspection Report 79-07) constituted a nonconformance. This analytical effort supports the position established in Section 3.12.3.5.1 of the FSAR. It also supports the fact that corrective action

.in compliance with criterion XVI of Appendix B to 10CFR50 has been and is being taken with respect to the identified conditions.

In those-few' cases where deviations from the minimum separation criteria were required due to ficid conditions, such as those indicated.by Inspection Report 79-07, the analysis demonstrated that the consequences of a failure would not have a significant

! -impact. That-is, since the analysis assumed that all'the cables L in an affected area were lost,-whether or.not minimum separation was maintained, the required-deviation will not compromise the safe shutdown capability.

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Mr. Robert T. Carlson April 16, 1980 Re: NRC Inspection No. 79-07 . Page 3 If requested, the results of the analysis could be submitted to the NRC, allowing approximately four months for formal preparation and review of an FSAR amendment end/or supplement.

However, we believe that the concerns raised by NRC Inspection Report 79-07 can best be resolved by an on-site review of the separation analysis by I&E.

Very tr y yours,

. P. Novarro, troject Manager i

Shoreham Nuclear Power Station RH/cc cc: J. Higgins -

J. N. Wilson i

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