ML20024C340

Forwards Revised Draft Responses to Draft SER Items 2,3,8 & 9 Re Fuel Rod Mechanical Fracturing & Fuel Assembly Structural Damage.Responses Will Be Incorporated Into FSAR Scheduled for Release in Aug 1983

ML20024C340
Person / Time
Site:	Limerick
Issue date:	07/08/1983
From:	Bradley E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Schwencer A Office of Nuclear Reactor Regulation
References
NUDOCS 8307120534
Download: ML20024C340 (7)

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PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 EDw ARD G. m AuER. JR.

weca Poussommy asse essesmat soument EUGENE J. BR ADLEY assoceave sanomas counset DON ALD BLANNEN RUDOLPH A. CHILLEMI E. C. MIM M H A LL T. H. M AHER CORMELL PAUL AUERBACH a.....am,e.e...am.oon...

Eow A Ro J. CuLLEn. J R.

THOM AS H. MILLER. J R.

July 8, 1983 l IRENE A. McMENN A messerant counssk Mr. A. Schwencer, Chief Licensing Branch No. 2 1 Division of Licensing l U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Subject:

Limerick Generating Station, Units 1 & 2 Response to Core Performance Branch Draft Safety Evaluation Report Re fe rence : 1) A. Schwencer to E. G. Bauer, Jr.

letter dated March 11, 1983

2) E. J. Bradley to A. Schwencer, letter dated May 25, 1983 File: GOVT l-1 (NRC)

Dear Mr. Schwencer:

The attached documents are revised draft responses to Core Performance Branch Draft Sa fety Evaluation Report items 2, 3, 8 and 9. The information contained on these draft responses will be incorporated into the FSAR, exactly as it appears on the attachments, in revision scheduled for August, 1983.

Sincerely, I

Euge e J Bradley RJS/cw/P-99 cc: See Attached Service List N'

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8307120534 830700 PDR ADDCK 05000352 dU E

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PDR

a cc: Judge Lawrence Brenner (w/o enclosure)

Judge Richard F. Cole (w/o enclosure)

Judge Peter A. Morris (w/o enclosure)

Troy B. Conner, Jr., Esq. (w/o enclosure)

Ann P. Hodgdon (w/o enclosure)

Mr. Frank R. Romano (w/o tenclosure)

Mr. Robert L. Anthony (w/o enclosure)

Mr. Marvin I. Lewis (w/o enclosure)

Judith A. Dorsey, Esq. (w/o enclosure)

Charles W. Elliott, Esq. (w/o enclosure)

Jacqueline I. Ruttenberg (w/o enclosure)

Thomas Y. Au, Esq. (w/o enclosure)

Mr. Thomas Gerusky (w/o enclosure)

Director, Pennsylvania Emergency Management Agency (w/o enclosure)

Mr. Steven P. Hershey (w/o enclosure)

' Donald S. Bronstein, Esq. (w/o enclosure)

Mr. Joseph H. White, III (w/o enclosure)

David Wersan, Esq. (w/o enclosure)

Robert J. Sugarman, Esq. (w/o enclosure)

Martha W. Bush, Esq. (w/o enclosure)

Spence W. Perry, Esq. (w/o enclosure)

Atomic Safety and Licensing Appeal Board (w/o enclosure)

Atomic Safety and Licensing Board Panel (w/o enclosure)

Docket and Service Section (w/o enclosure)

= . - - . - ..- ._ _ _ - - . - . - . _. _ _

DRAFT SAFETY EVALUATION REPORT ITEMS CORE PERFORMANCE BRANCH Question (2) - Fuel Rod Mechanical Fracturing The term " mechanical fracture" refers to a cladding defect j that is caused by an externally applied force such as a hydraulic load or a load derived from core plate motion. These loads are bounded by the loads of a LOCA and SSE, and the mechanical fracturing analysis is usually done as a part of the seismic-and-LOCA loads analysis (see Sec t ion 4. 2. 3. 3(4 ) of this report).

Because that analysis has not been completed for Limerick, it is not clear what design limit will be used for the mechanical fracturing analysis. This is an open item.

Response

Preliminary evaluations have been performed for the Limerick fuel assemblies in accordance with the methodology presented in NEDE-21175-3-P. These preliminary results indicate that:

(1) the most limiting accelerations experienced by the assembly will be no greater than 2.0g horizontal and 4.0g vet tical, and

(2) the fuel lift gap between the lower tie plate and fuel support casting is no greater than 0.2 inch.

Even though the final Limerick results will not be available until August 12, 1983, the preliminary results are consistent with the BWR 4 /5 fuel design, and hence can be used to predict the adequacy of the Limerick design. As shown in Table I, substantial margin exists in the Limerick design to assure that:

(1) the stress due to dynamic loading is well within the code allowables per the NUREG-0800 guidelines, (2) a coolable geometry is maintained in-the core, and f

(3) the fuel assembly response will not interfere with the movement of the control rods.

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DRAFT SAFETY EVAlliATION REPORT' ITEMS CORE PERFORMANCE BRANCH TABLE 1

. Limerick Fuel Assembly Load Comparison Limerick Allowable

-Vessel Size BWR 4 /251 -

Channel Thickness (mil.) 100 -

I Horizontal Acceleration (g) <2.0 3.6 Vertical Acceleration (g) <4.0 12.0(I Fuel Lift Cap (in) <0.2 0.52 (1) Allowable for 100 mil channel

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DRAFT SAFETY EVALUATION REPORT ITEMS CORE PERFORMANCE BRANCH 2 p Question (3) - Fuel Assembly Structural Damage From External Forces Earthquakes and postulated pipe breaks in the reactor coolant ayetem would result in external forces on the fuel assembly.

NUREG-0800, Section 4.2, and Appendix A to that section state that. fuel system coolability should be maintained and that damage should not be so severe as to prevent control rod insertion when it is required during these low probability accidents.

Because GE has not completed this cualysis for Limerick, it is not clear what the exact design limits will be, but they must follow the guidelines o f NUREG-0800 Sec t ion 4. 2, Appendix A.

This is an open item.

Response

This question is addressed in the response to Question (2).

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DRAFT SAFETY EVALUATION REPORT ITEMS CORE PERFORMANCE BRANCH DRAFT Question (8) - Fuel Rod Mechanical Fracturing The mechanical fracturing analysis is usually done as part of the seismic-and-LOCA loads (see Sec tion 4.2.3.3(4 ) of this

. report). Because that analysis has not been completed for Limerick, the information on mechanical fracturing is not available.

This is an open issue.

' Response This question is addressed in the response to Question (2).

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'o DRAFT SAFETY EVALUATION REPORT ITEMS CORE PERFORMANCE BRANCH

-Question (9) - Fuel Assembly Structural Damage from External Forces An analysis'must be provided by the applicant that shows that the Limerick fuel meets the structural requirements (including liftoff) o f- Appendix A to Sec tion 4.2 o f NUREG-0800. Because the review o f a generic report (NEDE-21175-3-P) is not completed.

(Question incomplete).

Response

This question is addressed in the response to Question (2).

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