ML20071P051

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Confirms 830531 Telcon Correcting Gap Calculations of Fuel Lift Results Contained in Generic Rept NEDE-21175-3-P
ML20071P051
Person / Time
Site: LaSalle Constellation icon.png
Issue date: 06/01/1983
From: Schroeder C
COMMONWEALTH EDISON CO.
To: Schwencer A
Office of Nuclear Reactor Regulation
References
6685N, NUDOCS 8306070334
Download: ML20071P051 (2)


Text

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Commonwe:lth Edison O one First National Plaza, Chicago, Illinois O Address Reply to: Post Office Box 767 Chicago, Illinois 60690 June 1, 1983 Director of Nuclear Reactor Regulation Attention: Mr. A. Schwencer, Chief Licensing Branch No. 2 Division of Licensing U. S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

LaSalle County Station Unit 2 NPF-11 License Condition 2.C.(12) Fuel Lift Results NRC Docket No. 50-374 References (a): C.W. Schroeder letter to A. Schwencer dated May 19, 1983 providing LaSalle Specific Fuel Lift Results.

(b): GE BWR Generic Responses to NRC Questions on NEDE 21175-3-P via Letter o f April 19, 1983 from J.F. Quirk to C.O. Thomas (NRC).

(c): Telecon between A. Bournia, et al, (NRC) and C.W. Schroeder/G.R. Crane (CECO) on May 31, 1983.

Dear Sir:

Reference (a) provided NRC with the LaSalle Specific solutions for fuel lift as calculated by GE via the general model described in i NEDE-21175-3-P, as amended by inclusion of X-17 reactions at node 6 vice node 9 and thus reduced water spring elements acting on node 9. (This improved treatment is descirbed on page 19 of Reference (b). The LaSalle Specific solution for Unit 2 per Reference (a) covers to the specific loads tabulated on Table 3.9-4a where the calculated peak accelerations l are noted to be markedly less than the evaluation bases accelerations.

l The correct value for the calculated maximum fuel assembly gap is 0.160

( inch.

I i Reference (b) responded to NRC generic questions on the NEDE-21175-3-P l model,. input loads, margins, etc. Included in this reference is a i declaration that LaSalle 2 is the BWR 5/MK 2 plant used for generic treatment. A value of maximum fuel assembly gap of 0.120 inch is cited for the NEDE-21175-3-P model in Tables Q10-1 and Q10-2; however, by the i refinements discussed above (page 19 of Reference (b), this calculation

was amended to yield 0.187 as the maximum fuel assembly gap. This is i explicitly shown in Table Q10-3 of Reference (b). For the treatment in 0306070334 830601 PDR ADOCK 05000374

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Director of NRR June 1, 1983 generic report NEDE-21175-3-P, the General Electric Company inferred on page 20 that the model was reasonable in that no significant conclusions were affected and further promised to revise the model to incorporate the node 6 changes at a future date (see page 21). The reason for a different LaSalle 2 gap in the generic study, contrasted to the correct gap reported in the first paragraph, is that the generic report applied the physical layout of Unit 1 to this Unit 2 calculation. That assumption is invalid for the LaSalle 2 Specific calculation because the vessel skirt is different and the nozzle attachments are slightly different also. The vessel moment is different at the RPV pedestal plane. The generic value of 0.187 in gap for Unit 2 is not the correct number for LaSalle; nor is the 0.120 inch generic value for the reasons cited above.

This letter confirms the Reference (c) celecon, which provided this same information to clear NPF-ll License Condition 2.C.12(b).

One (1) signed original and forty (40) copies of this letter are provided for your use.

If there are any further questions in this matter, please contact this office.

Very truly yours, r./i/83 C. W. Schroeder Nuclear Licensing Administrator 1m cc: NRC Resident Inspector - LSCS 6685N k