ML20086T386

Comment Opposing Proposed NRC GL on Testing of safety- Related Logic Circuits

ML20086T386
Person / Time
Site:	Monticello
Issue date:	07/20/1995
From:	Richard Anderson NORTHERN STATES POWER CO.
To:	NRC
References
FRN-60FR27414 60FR27414-00002, 60FR27414-2, NUDOCS 9508030005
Download: ML20086T386 (2)

Text

koFR2rM y W g 7/22/9s l

B.Gci mes Northem States Power Comparty g

,. 414 Nicollet Mall M '#33

^

Minneapolis, Minnesota 55401 1927

/3 TB}egge (612) 330-5500

. ,c.

dS;Q - * . i R July 20,1995 Chief, Rules Review and Directives Branch US Nuclear Regulatory Commission Washington, DC 20555-001 MONTICELLO NUCLEAR GENERATING PLANT PRAIRIE ISLAND NUCLEAR GENERATING PLANT Proposed NRC Generic Letter on .

Testina of Safetv-Related Loaic Circuits Northern States Power Company has reviewed the proposed generic letter, with subject Testing of Safety-Related Logic Circuits, noticed for public comment in the Federal Register on May 22. In response to previously issued NRC information notices, we have conducted reviews of safety-related circuitry to evaluate the concems identified by the specific deficiencies which have been previously noticed. It is not apparent that the proposed generic letter would provide any added safety benefit to those reviews previously conducted, except to unnecessarily expand the scope of those reviews. We do not feel the issuance of the proposed generic letter is warranted and provide the following specific comments.

Requested Action (1) of the proposed NRC Generic Letter states Compare electrical schematic drawings and logic diagrams... against technical specification surveillance test procedures to ensure that all portions of the logic circuitry, including parallel logic, inte.tocks, bypasses and inhibit circuits, are adequately covered in the surveillance procedures. This review should also include relay contacts, control switches, and other relevant electrical components within these systems, ,

utilized in the logic circuits. l This wording is unacceptable as it greatly expands the intent of plant technical specifications, and thus, by generic letter, the scope of required technical specificatien testing.

In the Discussion section of the May 22 FederalRegister notice the staff uses the following wording to describe equipment which may be affected by the identified potential vulnerability:

" essential electric components required for automatic actuation of post-accident mitigation systems."

This is the most accurate description of the equipment which should be subject of the review  !

recommend by this proposed generic letter and which has been reviewed due to previous NRC generic communications. Considerable industry and NRC staff effort has been expended to ensure the scope of such logic testing is not unnecessarily broad. NUREG -1433, Standard  ;

I 7/16/95 NSP H \ DATA \NRCCORR\ LOG-CKT. DOC  ;

9508030005 950720 l PDR ADOCK 05000263 NO P PDR

1 ,

I Technical Specifications, General Electric Plants, BWR/4, Rev 1,4/7/95, defines logic system l functional test as: '

A LOGIC SYSTEM FUNCTIONAL TEST shall be a test of all REQUIRED logic  ;

components (l. e., all REQUIRED relays and contacts, trip units, solid state logic elements, etc.) of a logic circuit, from as close to the sensor as practicable up to, but not including, the actuated device, to verify OPERABILITY.  ;

10 CFR 50.38(c)(3), Technical Specifications, Surveillance Requirements, states:

Surveillance requirements are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that  !

facility operation will be within the safety limits, and that the limiting conditions of  ;

operation will be met.  !

The proposed wording of required action 1 of the proposed generic letter expands the _

applicability of logic circuit functional testing as currently described in the Staff's discussion of the potential vulnerability in the proposed generic letter, as specified in NUREG-1433, and as

• required by regulation. Expanding the scope of such logic circuit testing to include all portions _;

of the logic will result in components being tested which are not relied upon as part of the -

plant safety analyses, nor relied upon by the limiting safety settings or limiting conditions of - i operation specified by the plant technical specifications. Such an expansion of scope will  :

result in a significant economic impact with no improvement in the level of protection provided .

to the health and safety of the public. NUREG-1433 recognized in its definition of Logic  :

System Functional Testing that there are portions of these circuits which do not perform any l safety function. We feel that if the NRC remains resolved to issue a generic letter on this -!

subject, that the intent of the proposed Generic Letter can be realized by a more focused i review. We recommend the following altemate wording for Requested Action (1): ,

Compare electrical schematic drawings and logic diagrams for the reactor' protection  ;

system, EDG load shedding and sequencing'and actuation logic for the engineered .;

safety features systems against technical specification surveillance test procedures to ,

ensure that electric comoonents reauired for autornatic actuation of Dost-accident  :'

mitioation system are adequately covered in the surveillance procedures.

We appreciate the opportunity to comment on this proposed generic letter. Please contact  !

Marv Engen, Sr Licensing Engineer, at (612) 295-1291 if you require further information.

7 i- @

RogerO. Anderson Director, Licensing & Management issues c: Regional Administrator-Ill, NRC Monticello NRR Project Manager, NRC Monticello Resident inspector, NRC Prairie Island NRR Project Manager, NRC l Prairie Island Resident inspector, NRC J. Silberg 7/18/95 NSP H \MTA\NRCCORR\ LOG-CKT. DOC

_. __