ML20092J902

Technical Evaluation Rept,Arkansas Nuclear One,Unit 2, Seismic Qualification of Auxiliary Feedwater Sys

ML20092J902
Person / Time
Site:	Arkansas Nuclear
Issue date:	09/24/1982
From:	LAWRENCE LIVERMORE NATIONAL LABORATORY
To:	NRC
Shared Package
ML20092J908	List: ML20092J902
References
GL-81-14, NUDOCS 8406270273
Download: ML20092J902 (4)

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Septeri.ber 24, 1982 i

TECHNICAL EVALUATION REPORT l l ARKANSAS NUCLEAR ONE,lNIT 2 SEISMIC QUALIFICATION OF AUXILIARY FEEDWATER SYSTEM

1. INTRODUCTION Since the accident at Three Mile Island, considerable attention has i

been focused on the capability of nuclear power plants.to reliably remove decay heat. The NRC has recently undertaken Multiplant Action Plan C-14

" Seismic Qualification of AFW Systems" [Ref.1], which is the subject of inis evaluation.

To implement the first phase of Action Plan C-14, the EC issued Generic Letter No. 81-14 " Seismic Qualificatiort of AFW Systems" [Ref. 2], dated February 10, 1981, to all operating PJtfLlicensees. This letter requested each licensee (1) to conduct a walk-down of norwseismically qualified portions of the AFW system and identify deficiencies amenable to simple ,

actions to improve seismic resistance, and (2) to provide design information regarding the seismic capability of the AFW system to facilitate NRC backfit decisions.

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The licensee of Arkansas Nuclear One, Unit 2 responded with a letter dated August 7,1981 [Ref.3]. The licensee's response was found not,to be complete and a Request for Additional Information (RAI) was issued by the E C, dated April 29, 1982 [Ref.4]. The licensee provided a supplemental response in a letter dated May 27,1982 [Ref.5].

This report provides a technical evaluation of the information provided in the licensee's responses to the Generic Letter, and includes 3

a recommendation regarding the need for additional analysis and/or upgrading modifications of this plant's AFW system.

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2. EVALUATION Information provided in licensee's responses included:

o Specification of the overall seismic capability of the AFW system.

o Description of methodologies and acceptance criteria for seismic design of the AFW system, which is determined to be seismically qualified to the SSE level by the licensee.

o Description of the AFW system boundary.

o Status of compliance with seismic related NRC Bulletin's and Information Netices.

Wehavereviewedthelicensee'srespnses,andapoint-by-point evaluation of licensee's responses against Generic Letter's requirements is provided below. ~~

(1) Seismic Capability of AFW System The AFW system has been designed, constructed, and maintained to withstand an SSE utilizing methods and acceptance criteria consistent with that applicable to other safety-related systems in the plant. All areas of the AFW system, i.e., pumps / motors, piping, valves / actuators, power supplies, water source, instrtment/ control systems, and structures supporting and housing the AFW system, are seismically qualified to the SSE level.

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The licensee provided a, description of the methodologies and acceptance criteria used for seismic qualification of the AFW system, and referred to the applicable sections of the FSAR. The description includes seismic analysis methods, seismic. input, load combinations, allowable stresses, qua811rication testing, and engineering evaluations performed.

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Because the primary water source and supply path is seismically qualified, switchover to a secondary water source is not involved.

, Additional information regarding the seismic capability of any alternate decay heat removal system is not required because the AFW system currently has an SSE level of seismic capability.

Regarding the AFW system boundary, the licensee did not clarify ','

whether the boundary fully conforms to the definitions given in the l

Generic Letter 81-14 with respect to branch piping being qualified out f to the second valve normally closed or capable of automatic closure when i function is required or to a point of three orthogonal restraints.

The licensee stated that the AFW system was included within the scope of the seismic related EC Bulletins 79-02, 79-04, 79-07, 79-14, 80-11, and IE Information Notice 80-21.(2)

(2) Walk-Down of Non-Seismically Qualified Portions of AFW System

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A walk-down is not required because no lack of seismic qualification of the AW system is indicated.

3. CONCLUSIONS The information contained in licensee's responses to Generic Letter 81-14 is complete except that it did not clarify whether the AFW system '

l boundary fully conform to the definitions of Generic Letter 81-14.

Based on the submitted information, we conclude that the AFW system is fully seismically qualified and is able to provide the safety related function following an SSE assuming that the AFW system boundary fully conform to the boundary definitions specified in GL 81-14. Therefore, we recommend that no further action be initiated regarding upgrading of the AFW systems of this plant under NRC Multiplant Action Plant C-14.

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REFERENCES

1. D. G. Eisenhut, U. S. t$Jclear Regulatory Commission, memorandum to H.

R. Denton, "Multiplant Action Plan C-14; Seismic- Qualification of Auxiliary Feedwater Systems," February 20, 1981.

2. U. S. Nuclear Regulatory Commission, Generic Letter No. 81-14 to all operating pressurized water reactor licensees, " Seismic Qualification of Auxiliary Feedwater Systems," February 10, 1981.

3. D. C. Trimble, Arkansas Power and Light Company, letter to D. G.

Eisenhut of U.S. Nuclear Regulatory Commission, August 7,1981.

4. USM C, letter to Arkansas Power and Light Company, " Request for Additional Information on Seismic Qualification of the Auxiliary Feedwater System, Arkansas Nuclear One, Unit 2," April 29,1982.

5. J. R. Marshall, Arkansas Power and tight Co., letter to R. A. Clark of USNRC, May 27, 1982. _

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