ML17037C492

Letter Requesting Additional Information on Authorization to Refuel the NMP Unit 1 Reactor with Up to 120 Fuel Bundles of the 8 X 8 Design

ML17037C492
Person / Time
Site:	Nine Mile Point
Issue date:	02/06/1974
From:	Ziemann D US Atomic Energy Commission (AEC)
To:	Raymond P Niagara Mohawk Power Corp
References
Download: ML17037C492 (6)

Text

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~ocket File AEC PDR FEB6 Local PDR RP Reading No. 50-220 i'ocket Branch, Reading JRBuchanan, ORNL DJSkovholt, L:OR TJCarter, L:OR ACRS (16)

Niagara Hohawk Power Corporation RO (3)

OGC ATTN: Mr. Philip D. Raymond Vice President - Engineering DLZiemann, L:ORB 82 CJDeBevec, L:ORB t/2 300 Exie Boulevaxd Qest RHDiggs, L:ORB //2 Syracuse, Hew York 13202 SVarga, L:RP Gentlemen Your lettex dated September 14, 1973, requested authorization to refuel the Nine Hile Point Unit 1 {Q1P-1) reactor with up to 120 fuel bundles of the 8 X. 8 design. You have submitted additional information con-cexning this proposed reload fuel by letters dated October 15, 1973, January 15 ind January 22, 1974. Ue have reviewed this information and find that the additional information listed in the enclosure is necessary to continue our review and evaluation. The requested information refers to your submittal dated January 15, 1974-Me request that the additional information be pxovided by February 19, 1974, with one signed original and thirty-nine additional. copies.

Sincerely, apjg1Ilal "-~GGCd b7 DCRR~ L. Qcmann Dennis L. Ziemann, Chief Operating Reactors Branch 82 Directorate of Licensing

Enclosure:

Request for Information cc w/enclosure:

J- Bruce HacDonald, Esquire Dr. 1H.11iam Seymour Deputy Commissioner and Counsel Staff Coordinator Hew York State Department of New York State Atomic Energy Council Commerce and Counsel to the Hew York State Department of Commerce Atomic Energy Council Anthony Z. Roisman, Esquire Arvin E. Upton, Esquire Berlin, Roisman and Kesslex LeBoeuf, Lamb, Loiby 6 HacRae or riced , L:ORB f/2 J.', L X7403 sveNAMe~ CJDeBevec:sj DL iemann 0

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1. Attaciunent A uestion 5 Although comparisons of predictions with results from the 8 z 8 stainless steel bundle spray cooling tests indicate, that the core heatup model slightly ovcxpxedicts the test results,'he steady state radiation test results are underpredicted. Furtheraure, the relatively thick clad of the stainless steel heaters may have xesulted in circumferential temperature gradients which are significantly low'er than presonted in a fuel assembly. Pro-vide thc calculated individual fuel rod clad temperatures and shd.laxly individual rod clad temperatures obtained from the 8 x 8 zircaloy test bundle to enable us to determine whither peak clad temperatures in a fuel assembly can be adequately predicted.

2. Attachment A uestion 7 The statement in response to question 7 that "dryout times predicted by the non-get pump corxelation are a function of the bundle average surface heat flic" is incorrect. As shown on Figure C-1 of APED-5458, the dryout time is 26K of the ratio of the energy required to vapoxize all the fluid in the test.

section to the total energy addition rate to the test section.

The total energy addition rate is the same for 8 x 8 and 7 z 7 fuel assemblies. However, the energy xequired to vaporize the fluid in an 8 2. 8 assembly is less than in a 7 x 7 assembly since the lower flow rate in an 8 x 8 assembly results in a higher average quality. Provide clarification of the information.

3. Attachment A uestions 7 and 8 Justify and explain the relevance of Lhe statement made in response to question 8 that "the blowdcr~ is assumed to continue until the vessel pressure is at 35 psia in the current analysis since the break flow will still be critical at this pressure or lese".

Since the containment analysis shows that the break flow is essentially zero at 20 seconds, and the pressure is 22 psig, what is the basis for assuming flow beyond 20 seconds2 OPPICC~

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b What is the relevance of break flow in the calculation of blowdown heat transfer coefficients. Since break flow would affect heat transfer in both types of assemblies similarly, justify using a long blowdown time for 8 x 8 assemblies relative to 7 x 7 assemblies.

4. Attachment A uestions 7 and 8 The ana3gsis of 8 x 8 assemblies using dryout and end-of-blowdown times Chat are longer Chan those used in the analysis of 7 x 7 assemblies is unjustified. Submit curves of peak clad temperature versus time assuming the dryout tines, heat transfer coefficients, and blowdmm times used to calculate the temperatures in 7 x 7 assemblics and presented in response to question 8.

5. At tachment 3 uestion 4.4 The statement in response to question 4-4 that the requested information was provided in a September 14, 1973 letter is incorrect. Hot channel flow rate, bundle power, axial and local peaking factors, snd exit. void fraction were requested. Table 2

'of the September 14, 1973 letter provides only hot channel flow.

Page 3 of the letter provides peaking factors, but does not relate them to the results in Table 2. Ho rod-to-rod peaking factors are provided. Only core average void fraction is given in Table 2.

Provide the requested information.

OPTICS~

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