ML20198H521

Safety Evaluation Supporting Amend 93 to License DPR-3

ML20198H521
Person / Time
Site:	Yankee Rowe
Issue date:	05/20/1986
From:	Office of Nuclear Reactor Regulation
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ML20198H476	List: ML20198H521
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NUDOCS 8605300479
Download: ML20198H521 (5)

Text

. '# UNITED STATES 8 k NUCLEAR REGULATORY COMMISSION

'5 9 E WASHINGTON, D. C. 20555

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION

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SUPPORTING AMENDMENT NO. 93 TO FACILITY OPERATING LICENSE NO. DPR-3 YANKEE ATOMIC ELECTRIC COMPANY YANKEE NUCLEAR POWER STATION DOCKET NO.50-029

1.0 INTRODUCTION

By letter dated March 28, 1984, additional information submitted May 3, 1984 and supplemented May 7,1985, the Yankee Atomic Electric Company (YAEC) submitted a request for changes to the Yankee Nuclear Power Station Technical Specifications (TS).

The amendment modifies the TS to: (1) allow movement of spent fuel pit buildin and (2)gallow hatches (except use of the crane the travel cask hatch to move cover) overhatch the cask the spent coverfuel overpit; the spent fuel pit building, except that movement over fuel assemblies in the spent fuel pit will be prohibited.

2.0 EVALUATION In a letter dated March 28, 1984, the licensee for the Yankee Nuclear Power Station (Yankee), the Yankee Atomic Electric Company (YAEC), requested a change in the Technical Specifications to move the various spent fuel pit (SFP) building hatches, the temporary gate and the shield panels on the SFP building with the following restrictions;

1. Furthest north roof hatch (cask hatch cover) - without restriction,

2. All the remaining equipment in accordance with the following schedule:

"4.9.7.2 Spent fuel pit building hatches (excluding the cask hatch cover), the temporary gate, and the shielding panels shall not be permitted to be moved over the fuel pit unless:

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(a) With newly discharged spent fuel stored in the lower racks, all spent fuel in the spent fuel pit has decayed for at least 45 days for 76 Newly Discharged Spent Fuel Assemblies (NDSFA), 37 days for 40 NDSFA, and 36 days for 36 NDSFA, or (b) With newly discharged spent fuel stored in the upper racks, all spent fuel in the spent fuel pit has decayed for at least 60 days for 76 Newly Discharged Spent Fuel Assemblies (NDSFA), 45 days for 40 NDSFA, and 43 days for 36 NDSFA."

In response to a request by the NRC on April 17, 1984, YAEC provided addi-

, tional supporting analysis in a submittal dated May 3, 1984. In response to additional staff concerns provided to the licensee in a letter dated July 26, 1984, the licensee provided further information and a supplemental TS in a submittal dated May 7, 1985. In the May 7, 1985 submittal the licensee responded to the staff's recommendations by modifying their Technical Speci-fications to restrict the movement of the cask hatch cover. We find that the implementation of this Technical Specification provides a satisfactory resolution to the additional concerns regarding the potential hazard posed by the roof hatch cover.

In the matter of criticality, YAEC cited NUREG-0612. " Control of Heavy Loads at Nuclear Power Plants," which states that no potential for criticality appears to exist as a result of a heavy load drop in a PWR spent fuel pool containing only spent fuel. The licensee performed a criticality analysis to ascertain the maximum fuel enrichment for assemblies in the racks in the SFP with the following conservative assumptions:

1. Fresh fuel;

2. Temperature - 68'F;

3. No soluble boron in pool;

4. No radial or axial leakage;

5. 10.94 canister center to center spacing; and

6. Minimum boral plate, stainless rack thickness using a fuel enrichment of 4.5%.

The maximum k We find this assumption acceptable;t$$(wasfoundtobe0.8932.

criticality will not occur in the SFP as a result of a drop of a heavy load consisting of those permitted over the spent fuel pool by the revised Technical Specification 4.9.7.1.

The NRC staff requested that YAEC demonstrate that a heavy load drop on irradiated fuel in the SFP would not exceed the design basis criteria specified in Standard Review Plan Section 15.7.4, " Radiological Consequences

! of Fuel Handling Accidents." The licensee cited two previous analyses -

one conservative analysis in which 721 newly discharged assemblies in the upper tier were damaged after a 90 day decay period, and the second analysis in which 76 newly discharged assemblies in the lower tier were damaged

, after a 45 day decay period. Both analyses assumed a release of 10%

of the gap activity. In the former analyses, the thyroid dose limit was less than 100 rem, in the latter less than 75 rem. The

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changetoTechnicalSpecifications4.9.7.2(a)and4.9.7.2(b) would proposed permit movement of SFP building hatches, the temporary gate and shielding panels after NDSFA have decayed according to the following schedule: i MINIMUM DECAY TIME

NDSFA Stored In NDSFA Stored In NDSFA Lower Racks .

Upper Racks 36 36 days 43 days 40 37 days 45 days 76 45 days 60 days The staff has performed an analysis of YAEC's submittal. We have determined that the proposed Technical Specifications would assure that offsite doses would not exceed the dose guidelines contained in Standard Review Plan 15.7.4 l

in the event of a heavy load drop. Therefore, the staff finds the proposed amendment acceptable.

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3.0 ENVIRONMENTAL CONSIDERATION

This amendment involves a change to a requirement with respect to the installation or use of facility components located within the restricted j

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area as defined in 10 CFR Part 20 and changes to the surveillance require-ments. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assess-ment need be prepared in connection with the issuance of this amendment.

4.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, and (2) public such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common '

defense and security or to the health and safety of the public.

5.0 ACKNOWLEDGEMENT Principal Cor.tributors: C. Ferrell, N. Wagner and H. Gilpin

! Dated: May 20, 1986 1

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MAY 2 0 D33 DISTRIBUTICN:-

Docket Files-NRC PDR Local PDR J. Clifford G. Lear P. Shuttleworth OELD L. Hamon E. Jordan B. Grimes J. Partlow T. Barnhart (4)

ACRS (10)

OPA LFMB PD#1 r/f PD#1 s/f T. Novak E. Butcher /TSCB l

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