ML20134N530

Application to Amend License DPR-3,changing Tech Specs Re Core Inlet Temp & Lhgr.Proposed Tech Spec Changes & Yankee Nuclear Power Station Core Xviii Performance Analysis Encl. Fee Paid

ML20134N530
Person / Time
Site:	Yankee Rowe
Issue date:	08/30/1985
From:	Heider L YANKEE ATOMIC ELECTRIC CO.
To:	Office of Nuclear Reactor Regulation
Shared Package
ML20134N533	List: ML20134N530 ML20134N538 ML20134N542
References
FYR-85-91, NUDOCS 8509050180
Download: ML20134N530 (4)

Text

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Te'ephone (6") 8' 8 'o0 YANKEE ATOMIC ELECTRIC COMPANY TWX 710-380-7619

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1671 Worcester Road, Framingham, Massachusetts 01701 2 *

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August 30, 1985 United States Nuclear Regulatory Commission Washington, DC 20555 Attention: Office of Nuclear Reactor Regulation

References:

(a) License No. DPR-3 (Docket No. 50-29)

(b) YAEC Letter to USNRC, dated February 21, 1984 (FYR 84-22) and Supplement, dated May 17, 1984 (FYR 84-58)

(c) YAEC Letter to USNRC, dated August 16, 1985 (FYR 85-88)

(d) USNRC Letter to YAEC, dated May 22, 1985 (NYR 85-88)

Subjo- : Core XVIII Refueling - Cycle-Dependent Parameters Dear Sir Pursuant to Section 50.59 of the Commission's Rules and Regulations, the Yankee Atomic Electric Company hereby requests the authorization to make the following changes:

PROPOSED CHANGE Reference is made to the Technical Specifications and the " Yankee Nuclear Power Etation Core XVII Performance Analysis" [ Reference (b)) of License No. DPR-3.

1. We propose to refuel the reactor for Core XVIII operation by replacing 40 fuel assemblies.

2. We propose to modify the Technical Specifications for the reasons described below. The proposed Technical Specification changes are given in Attachment A.

REASON AND BASIS FOR CHANGE Technical Specification changes are proposed for:

1. A SOF increase in the maximum allowable core inlet temperature to accommodate possible future increased in this parameter;

2. A Linear Heat Ceneration Rate (LHGR) limit based on a revised LOCA analysis that takes into account worst-case axial power shapes in order to assure compliance with Appendix K of 10CFR, Part 50; bho e t /* iU yYfo y*.Ma/Dsr/Wa o fon ws MM i ,

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United States Nuclear Regulatory Commission August 30, 1985 Attention: Office of Nuclear Reactor Regulation Page 2 '

3. A revised basis for determining control-rod-motion-related peaking' multipliers to be applied to measured LHGR for comparison to the LOCA limit, consistent with the revised basis for determining the LOCA limit mentioned above;

4. Statistically combining independent uncertainty parameters for

[ applicat:on to the measured LHGR to provide a conservative upper l bound for comparison to the LOCA limit; and

5. A setpoint change to the Safety Injection Actuation Signal (SIAS) from 1700 psig to 1650 psig in order to avoid inadvertent Safety Injection actuations on reactor trips.

The specific changes and reasons for the changes are shown in Attachment A. The Core XVIII performance Analysis Report (YAEC-1496), which supports Core XVIII operation and provides the basis for the attached Technical Specification changes, is provided as Attachment B. This report ,

addresses the mechanical design, thermal-hydraulic design, physics and safety l analysis aspects of the refueling.

SAFETY CONSIDERATION Yankee Atomic has evaluated the Core XVIII reload and has concluded that it does not involve a significant hazards consideration. A summary of our evaluation follows:

As discussed in Attachment B, the fresh fuel assemblies used in the Core XVIII design are being manufactured by combustion Engineering and are not significantly different than those previously approved for use at the Yankee Nuclear Power Station. The acceptance criteria for the Technical f' Specifications associated with the Core XVIII design are the same as the l acceptance criteria for the current Technical Specifications. The analytical methods used to demonstrate conformance of the Core XVIII design have been previously found acceptable by the NRC except for a minor modification in methods employed to analyze the Loss-of-Coolant Accident (LOCA). The minor change to LOCA methodology was described in Reference (c). Discussions with the NRC staff indicate that the minor modification to our LOCA methodology will be acceptable. The same approach has been previously applied by Exxon Nuclear Corporation on other facilities. The NRC has previously approved the approach on these other plants. ,

Additional changes for Core XVIII include an increase in the maximum I allowable core inlet temperature from 5150F to 5200F, a setpoint change to SIAS from 1700 psig to 1650 psig, a revised LOCA analysis accounting for worst-case axial power shapes as requested in Reference (d), and a statistical method for combining independent uncertainty parameters for application to the l measured LHGR. These changes have been evaluated for the Yankee Core XVIII design.

The changes associated with Core XVIII do not affect the probability of an accident previously evaluated in the Yankee FSAR. The effect of Core XVIII

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l United States Nucleac Regulatory Commission August 30, 1985

! Attention: Office of Nuclear Reactor Regulation Page 3 L

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operation on the consequences of accidents previously evaluated in the Yankee j FSAR is presented in Sections 7 and 9 of Attachment B. As shown in N Attachment B, the consequences of accidents previously evaluated have not significantly increased and continue to be well within applicable acceptance criteria.

The changes associated with Core XVIII have been evaluated, and we have -

concluded that they do not create the possibility of a new or different kind of accident from any previously evaluated.

The margin of safety of the Core XVIII design in evaluated in Sections 4, 5, 6, 7 and 9 of Attachment B. The physics, fuel performance. thermal- i hydraulic and transient response characteristics of Core XVIII are not significantly different from previous reload cores, and thus, the Core XVIII .

design does not involve a significant reduction in the margin of safety.

In summary, the Yankee Core crIII Core Performance Analysis demonstrates that the Core XVIII design does not:

-1. Involve a significant increase in the probability or consequences of an accident previously evaluated; or

2. Create the possibility of a new or different kind of accident from any accident previously evaluated; or

3. Involve a significant reduction in a margin of safety.

Therefore, we have concluded that the Core XVIII design does not involve a significant hazards consideration.

Based on the consideration contained herein, it is concluded that there is reasonable assurance that operation of the Yankee plant consistent with the  !

proposed Technical Specifications will not endanger the health and safety of the public. This proposed change has been reviewed by the Nuclear Safety Audit and Review Committee.

FEE An application fee of $150.00 is enclosed in accordance with 10CFR170.21.

SCHEDULE OF CHANGE These changes to the Yankee Technical Specifications will be implemented upon Commission approval. A timely review and approval of this submittal consistent with our schedule for Core XVIII startup would be appreciated.

Therefore, since Core XVIII is scheduled to commence operation on November 30, 1985, we request approval of this submittal by November 11, 1985.

United States Nuclear Regulatory Conaission August 30, 1985 Attention: Office of Nuclear Reactor Regulation Page 4 We trust that you will find this submittal setisfactory; however, should you desire additional information, please contact us.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY L. H. Helder Vice President / Manager of Operations LHH/gms Attachments COMMONWEALTH OF MASSACHUSETTS)

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Then personally appeared before me, L. H. Heider, who, being duly sworn, did state that he is Vice President / Manager of Operations of Yankee Atomic Electric Company, that he is duly authorized to execute and file the foregoing document in the name a.nd on the behalf of Yankee Atomic Electric Company and that the statements therein are true to the best of his knowledge and belief.

l O+ " Y.,06.f- h p%44 .'Pj. Robert H. Groce Notary Public

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