ML20204H112

Submits Further Explanation of 840224 Request for Partial Exemption from GDC 4 Re Elimination of Postulated Pipe Breaks in Primary Coolant Loops.Fsar Changes Encl

ML20204H112
Person / Time
Site:	Beaver Valley
Issue date:	11/05/1984
From:	Woolever E DUQUESNE LIGHT CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
2NRC-4-183, GL-84-04, GL-84-4, NUDOCS 8411120160
Download: ML20204H112 (4)

Text

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'Af 4 78 si4i (412)9234 960 Nuclear Construction Division Telecopy (412) 787-2629 Robinson Plaza, Building 2, Suite 210 Pittsburgh, PA 15205 November 5, 1984 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation Nuclear Regulatory Commission Washington, DC 20055

SUBJECT:

Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 Elimination of Postulated Pipebreaks In Primary Coolant Loops

REFERENCES:

1. NRC Generic letter 84-04, Dated 02/01/84

2. DLC Letter 2NRC-4-017, Dated 02/24/84

3. NRC Letter to DLC, Dated 04/10/84

4. DLC ' Letter 2NRC-4-071, Dated 05/31/84

5. DLC Letter 2NRC-4-104, Dated 07/16/84 Gentlemen:

We have submitted our request for partial exemption from General Design Criteria (GDC) 4 of 10CFR50 Appendix A as it relates to the dynamic effects associated with RCS main loop pipe breaks (Ref. 2). Subsequently, we submitted the technical justification in support of elimination of postulated breaks in the primary coolant loops (Ref. 4) as requested in Ref. 3. Our submittal of WCAP-10565 (Ref. 5) concluded that specific parameters for BVPS-2 are enveloped by Westinghouse generic analysis in WCAP-9558 Rev. 2 which has been accepted by the NRC as stated in Generic Letter 84-04 (Ref.1).

The purpose of this letter is to further explain our request for partial exemption from GDC4. We are specifically requesting the elimination of all Double-Ended Guillotine Breaks (DEGB) on the primary coolant loop, eight per loop and one longitudinal split per loop on the hot leg elbow as

.shown on attached FSAR Table 5.4-22 and Figure 5.4-25 as break locations 1 through 8 and 12.

Elimination of these postulated breaks will have the following potential impact:

1. Primary coolant loop rupture restraints (including shims) will not be installed or will not be fitted and shimmed if installed (two restraints on crossover leg elbows, one restraint on hot leg and one restraint on cold leg for each loop).

2. Jet impingement shields required to protect against the ef fects of these postulated breaks will not be installed. (Target / break interactions for double-ended guillotine breaks are identified in Ref. 4, and the target for the longitudinal split on hot leg elbow is Line 2BDG-002-15-2.)

8411120160 $ [pDR 2 PDR ADOCK g

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Unittd Stctso Nucle r Regulctory Commission Mr. H.. R.'Dinton, Dirsetor Page 2

3. The primary loop LOCA load evaluation on primary loop piping, branch line piping, and branch line supports will be eliminated (branch line LOCA loads due to DEGB at three branch line terminal ends would be retained in the design basis).

4. Primary coolant systen equipment and their supports have been designed and constructed for the full spectrum of LOCA effects in conjunction with a safe shutdown earthquake. Granting of the exemption request will not alter the design of these supports.

5. A postulated reactor coolant loop break up .to and including a break area equivalent to a double-ended pipe break will be retained for design of ' emergency core cooling systems, overall containment system, equip-

-ment qualification, and ESF systems response.

6. Subcompartment pressurization analyses including asymmetric loads have been performed to demonatrate that the design can withstand the dynamic ef fects associated with the primary coolant loop postulated breaks.

A response from the NRC by no later than the end of 1984 is criti-cal .to Duquesne Light Company due to the demands of the construction schedule and the detailed planning necessary to support this sch edule . The saving of several million dollars would be realized in the area of design, procurement and installation activities associated with rupture restraints and jet im-

.pingement shields that would be eliminated if the exemption is granted.

Presently, the construction schedule requirea installation of rup-ture restraints to begin no later than January 1985. Also, design, procure-ment ' and installation of jet impingement . shields are on " hold" pending ap-proval of .this exemption request. A delay in the decision-making process by the NRC will severely impede the cost and safety advantage of this ef fort.

The FSAR will be anended to reflect the revised design bases for the above mentioned items once this partial exemption is granted.

Very truly yours, E. . Woolever Vice President Nuclear Construction Division SKM/ caw SUBSCRIBED AND WORN TO BEFORE ME THIS At tahnt s DAY OF - /Xt7mk ,1981 ST/EL/PIPEBREAK - <

cc: Mr. B. K. Singh, Project Manager i su_) L Mr. E. A. Licitra, Project Manager Notary Public Mr. G. Walton, NRC Resident Inspector ANITA ELAINE R

, NOTARY PUBLIC RoslNSON MY COMMiss of ES OB

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Mr. H. R. Denton, Director

_ Office of Nuclear Reactor Regulation Page 3 COMMONWEALTH OF PENNSYLVANIA )

) SS:

COUNTY OF.ALLECHENY )

On this g k day of ,

////,beforeme,a

. Not ary ' Public in and for said Commonwealth and County, personally appeared E. l J. ' Woolever, who being duly sworn, deposed and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set- forth .in the Submittal are true and correct to the best of his knowledge.

. 41/Lu >%. Notary Public ANITA ELAINE REITER, NOTARY PUBLIC ROBINSON TOWNSHIP, ALLEGHENY COUNTY MY COMMISSION EXPIRES OCTOBER 20,1986

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• 1*- Attachmento BVPS-2 FSAR f v. TABLE 5.4-22 POSTULATED PRIMARY LOOP BREAKS Break Location Type 1No.* of Break of Break 1- Reactor vessel outlet nozzle 1/2 Double-ended guillotine 2 Reactor vessel inlet nozzle 1/2 Double-ended guillotine 3- Steam gen'erator inlet nozzle Double-ended guillotine .

.w Steam generator outlet nozzle Double-ended guillotine

~

4 5 Reactor' coolant pump. inlet Double-ended guillotine nozzle 6

~

Reactor coolant pump outlet Double-ended. guillotine nozzle 7- 50-D[greeelbowat'the.SG Split inlet on the Intrados

.p,s b 8

~

Flow entrance to the Double-ended guillotine 90-degree elbow

-(steam generator side) on the crossover leg 9 Residual heat removal / primary Guillotine (viewed

• loop connection from the residual heat removal line)

-10 Safety injection / primary Guillotine (viewed coolant loop connection from the safety injection

- line)

-11 Pressurizer surge / primary Guillotine (viewed coolant loop connection fr 6 che pressurizer surge fina Loop. closure weld in cross- cc '--ended guillotine-12' over leg 2 -

NOTEt

• Refer to Figure 5.4-25.

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