1CAN078211, Responds to NRC 810929 Request for Submittal Re NUREG-0737, Item II.D.1, Pressurizer Safety/Relief Valve Operability. Subj Valves Function Predicted Under All Credible Operating & Accident Conditions Analyzed in FSAR

Responds to NRC 810929 Request for Submittal Re NUREG-0737, Item II.D.1, Pressurizer Safety/Relief Valve Operability. Subj Valves Function Predicted Under All Credible Operating & Accident Conditions Analyzed in FSAR

ML20062D882
Person / Time
Site:	Arkansas Nuclear
Issue date:	07/28/1982
From:	John Marshall ARKANSAS POWER & LIGHT CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM 1CAN078211, 1CAN78211, NUDOCS 8208060253
Download: ML20062D882 (3)

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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK. ARKANSAS 72203 (501) 371-4000 July 28, 1982 1CAN078211 Director of Nuclear Reactor Regulation ATTN: Mr. J. F. Stolz, Chief Operating Reactors Branch #4 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555

SUBJECT:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 NUREG-0737, Item II.D.1 Pressurizer Safety / Relief Valve Operability Gentlemen:

Pursuant to NUREG-0737, Item II.D.1 and your letter of September 29, 1981,(0CNA108105) Arkansas Power and Light is providing the following response to that request for submittal.

Item II.D.1.A of NUREG-0737 requires that utilities operating and/or constructing Pressurized Water Reactor (PWR) power plants provide evidence supported by test, of safety and relief valve functionability.

In response to these requirements, the Electric Power Research Institute (EPRI) implemented a generic test program on behalf of the PWR utilities.

Arkansas Power and Light has been a participant in the EPRI program. The NRC Generic Letter 81-36 dated September 29, 1981, contains a schedule for submittal of test results and plant-specific reports. The following documents were transmitted to you on April 1, 1982, by Mr. David Hoffman of Consumers Power Company on behalf of the PWR utilities participating in the EPRI studies and are incorporated herein by reference as part of this submittal.

o PWR Safety and Relief Valve Test Program L Valve Selection / Justification Report EPRI NP-2292-LD, April 1982 ,O" o Valve Inlet Fluid Conditions for Pressurizer Safety and Relief Valves for B&W 177-FA and 205-FA Plants EPRI NP-2352-LD, April 1982

.s o EPRI/PWR Safety and Relief Valve Test Program Test Condition Justification Report, April 1982 8208060253 e20728 DR ADOCK 05000333 PDR En MlOOLE SOUTH UTiuTIES SYSTEM

Mr. J. F. Stolz #3 July 28, 1982 o EPRI/PWR Safety and Relief Valve Test Program Safety and Relief Valve Test Report, April 1982 An itemized treatment of the individual requirements of NUREG-0737, II.D.1 for Arkansas Nuclear One-Unit 1 (ANO-1) follows.

1. Item II.D.1.A(1)

The EPRI Safety and Relief Valve Test Report referenced above provides data which show the ability of PWR pressurizer safety and relief valves to open and close under all operating and accident conditions as analyzed in the ANO-1 Final Safety Analysis Report (FSAR). It is our judgement that the tests performed provide substantial data to document the successful performance of valves representative of those installed at ANO-1. This judgement is based on an evaluation of the remaining items of NUREG-0737, Item II.D.1.A.

2. Item II.D.1.A(2)

The valves tested at the C-E facilities successfully bound the type and performance of the valves installed on ANO-1 based on the following:

a. The applicable safety valves tested, Dresser Model 31739A-1 and Model 31709NA-1, are geometrically and functionally similar in design to the Model 31759A-1 valves installed. Model 31739A-1 has a bore of 1.8 inches, while Model 31709NA-1 has a bore of 2.351 inches. Since the ANO-1 valves have bores of 2.062 inches, they are better represented by tested Model 31739A-1.

There are no data to predict significant differences in the operations of the AN0-1 valves under similar conditions.

b. The applicable relief valve tested by EPRI, Dresser Model 31533VX-30, is geometrically and func.tionally representative in design to the Model 31533VX-30 installed at ANO-1.

c. The short inlet piping modeled by the EPRI tests adequately represents the ANO-1 installation. Actually, the valves are installed on ANO-1 in a more conservative manner than modeled in the tests, i.e., the ANO-1 valves are installed on a flange mounted on the pressurizer, thus having a much shorter inlet pipe than modeled.

d. Inlet fluid conditions established for the EPRI tests are comparable or more conservative than the conditions presented in the referenced report, " Valve Inlet Fluid Conditions for Pressurizer Safety and Relief Valves for B&W 177-FA and 205-FA Plants".

e. The backpressure effects on operability of as-built safety and relief valve discharge piping are judged to be minimal and will not significantly affect the performance of these valves.

f. Although thera is no safety concern, future valve adjustments may be beneficial to assure optimal performance. We are

,' Mr. J. F. Stolz ") July 28, 1982 continuing to evaluate the EPRI data to determine if valve adjustments are necessary at ANO-1. In addition, input from the valve manufacturers is being requested and will be incorporated in the evaluation. If results of the evaluation indicate that adjustments are necessary, the settings will be altered accordingly.

3. Item II.D.1.A(3)

The test data are provided in the aforementioned EPRI " Safety and Relief Valve Test Report" for safety and relief valve operation.

Data from the EPRI tests have been used to benchmark a computer program which models the discharge piping and predicts the forces generated by changes in momentum of the fluid discharged. This program is currently being used to model AN0-1 discharge piping.

Loads resulting from these forces will be combined with thermal and deadweight loads to allow an evaluation of the adequacy of the existing piping system. The study should be complete by early October 1982, and if so, will be transmitted to you in November 1982. The delay in this area is a result of the EPRI data needed to benchmark the program being submitted behind schedule.

4. Item II.D.1.8 Analyses performed by each PWR NSSS vendor have shown that isolation of a stuck open power operated relief valve is not required to ensure safe shutdown, and is therefore not a safety issue. The demonstration of successful block valve testing at Duke Power Company's Marshall Station has been documented in the "EPRI/ Marshall Electric Motor Operated (Block Valve), Interim Test Report", May 31, 1982, and transmitted to your office by Mr. R. C. Youngdahl of Consumers Power Company on June 1, 1982. It is our intention to incorporate this document, by reference, as part of this submittal addressing Item II.D.1.B.

Based on our evaluation of the EPRI test results as applied to ANO-1 plant-specific conditions, it is concluded that the pressurizer relief and safety valves function as predicted under all credible operating and accident conditions analyzed in the FSAR. It is our judgement that continued operation with existing pressurizer safety, relief, and block valves will not adversely affect Operation or transient mitigation as described in the FSAR and attendant documentation.

Very t uly yours, f-John R. Marshall Manager, Licensing JRM:JC:sc Y

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