ML20154H098

Provides Supplemental Info for Two Reg Guide 1.97 Variables, Including Accumulator Tank Level & Pressure,Per Instrumentation & Control Sys Branch Comments

ML20154H098
Person / Time
Site:	Beaver Valley
Issue date:	03/03/1986
From:	Carey J DUQUESNE LIGHT CO.
To:	Knighton G Office of Nuclear Reactor Regulation
References
RTR-REGGD-01.097, RTR-REGGD-1.097 2NRC-6-018, 2NRC-6-18, TAC-62938, NUDOCS 8603100187
Download: ML20154H098 (3)

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.,,ei , 96 United States Neclear Regulatory Connission Washington, DC 20555 ATTENTION: Mr. George W. Knighton, Chief Licensing Branch 3 Of fice of Nuclear Reactor Regul ation l SU6 JECT: Beaver Valley Power Station - Unit No. 2 l Docket No. 50-412 l Regulatory Guide 1.97 Implenentation Report l

"Supplenental Information for Accunulator Tank Level and I , Pressure" l

REFERENCES:

1. DLC Activity Sunnary Report 2ASR-02064, dated August 20, 1985,

" August 20, 1985, DLC/NRC Meeting Summary"

2. DLC Letter 2NRC-5-095, dated June 25, 1985, " Regulatory Guide 1.97 Implenentation"

3. DLC Letter 2NRC-3-072, dated Septenber 12,1983, "Regul atory Guide 1.97, Implementation" l 4. NRC Letter dated April 13, 1985 (G. W. Knighton to J. J.

i Carey) " Beaver Valley Unit 2, Requests for Additional Informa-tion -- Confonnance to Regulatory Guide 1.97" Gentlenen:

l l The attachnent to this letter provides supplenental information for two Regulatory Guide (RG) 1.97 variables: accumulator tank level and pres-sure. This infonnation is provided to resolve the renaining conments fron NRC Instruinentation and Control Systens Branch for these variaDies and the BVPS-2 RG 1.97 Implenentation Report. Upon the review of this submittal, j please direct any conments in this regard to Mr. Erv Eilmann, Lead Engineer, Regulatory Aff airs Department.

l DUQUESNE LIGHT MPANY l

d( y(Cafey l V1tte Pr'esident l KEW/w]s Attachnent I cc: Mr. P. Tan, Project Manager (w/a)

Mr. G. Walton, NRC Resident Inspector (w/a)

Mr. J. Joyce, NRC ICSB (w/a)

I wanne A

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ATTACHMENT BVPS-2 Regulatory Guide 1.97 Implementation Report Supplemental Information for Accumulator Tank Level and Pressure DLC used the guidance of Regulatory Guide (RG) 1.97 to demonstrate that BVPS-2 complies with 10CFR50 General Desgn Criteria 13,19, and 64.

The Instrumentation and Control Systems Branch (ICSB) has indicated that the DLC submittals are acceptable to the NRC with the exception of two Type D variables: (1) accumulator level, and (2) accumulator pressure.

The BVPS -2 accumulator level and pressure instrumentation is described in FS AR Sectico 6.3. Two level and two pressure channels are provided for each accumulator. Each channel provides both indication and high/ low alarms in the main control room. DLC has classified accumulator level and pressure as Type D, Category III variables. The rationale for this classification includes the following considerations:

1. Accumul ator level and/or pressure indications are not used to prevent or mitigate the consequences of an accident.

2. Accumulator level and/or pressure channels do not initiate safety functions.

3. Accumulator level and/or pressure indications are not used during the BVPS-2 Emergency Procedures.

f 4 The BVPS-2 accinulator level and pressure instruments provide the reliable indications required to ensure compliance with Technical Specification 3/4.5.1. During normal operation, this specifica-tion requires monitoring these parameters once each 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, and provides that the plant be shutdown if either parameter remains outside its specified range for one hour.

5. Other post-accident qualified instruments provide indication of accumul ator injection, and these instruments are used in emer-gency procedures. Accumulators can be isolated if required by BVPS -2 emergency procedures. Accumul ator level and pressure indication does not impact isolation capability.

4 FSAR Section 6.3.2.2 describes the passive injection function which occurs when RCS pressure drops below accumulator pressure. FS AR Table 15.6.1 l shows that this passive function occurs either within one minute after the start of the LOCA event, or well after the safety injection pumps have started, depending on break size. In either event, the operator actions

( i .e. , T.S . 3/4.5.1 surveillance) which enables the accumulators to perform )

their intended function occur prior to the LOCA event and, therefore, prior to any postul ated post-accident environment. The Technical Specification surveillance, using the highly rel iable mul tiple channel instrumentation provided at BVPS-2 together with the statically passive accumulator design, provide a high level of confidence that the accumulators will perform their l

m o . o u intended safety function. The accumulator level and pressure indication ere suppl enented by highly reliable, safety grade active ECCS subsystens which enploy the design considerations described in FSAR Section 6.3. The charac-teristics of these ECCS subsystens include redundancy, equipnent qualifica-tion, single failure criteria, and independent power supplies.

The design of the BVPS-2 accunul ator level / pressure indic ation is >

simil ar to that of the SNUPPS (Wolf Creek and Call away) pl ants. Under contract to the NRC, EG&G Id aho , Inc. , evaluated the Callaway design and determined that these variables need not be post-accident qualified. The NRC endorsed this determination in its April 1985 SER. No exenption to regul a-tions was required in making this determination.

Based on the above infonnation, DLC believes the present design for indication of acctnulator level and pressure is adequate for use at BVPS-2 since it clearly meets the General Design Criteria upon which RG 1.97 is based.

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