NRC-96-0075, Application for Amend to License NPF-43,changing SLMCPRs in TS 2.1.2 to Reflect Results of cycle-specific Calculation Performed for Plant Operating Cycle 6 Expected to Commence in 1996 & Deleting Specific SLMCPR Value

Application for Amend to License NPF-43,changing SLMCPRs in TS 2.1.2 to Reflect Results of cycle-specific Calculation Performed for Plant Operating Cycle 6 Expected to Commence in 1996 & Deleting Specific SLMCPR Value

ML20117L023
Person / Time
Site:	Fermi
Issue date:	09/05/1996
From:	Gipson D DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20117L029	List: ML20117L038 NRC-96-0075, Application for Amend to License NPF-43,changing SLMCPRs in TS 2.1.2 to Reflect Results of cycle-specific Calculation Performed for Plant Operating Cycle 6 Expected to Commence in 1996 & Deleting Specific SLMCPR Value
References
CON-NRC-96-0075, CON-NRC-96-75 NUDOCS 9609120295
Download: ML20117L023 (8)

Text

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, Douglas R. Gipson Senior Vice President Nuclear Generabon Detroit . re-6400 North Dine Highway Ee Newport, Michigan 48166 (313) 586-5249 September 5,1996 NRC-96-0075 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555

References:

1) Femli 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) General Electric letter to NRC,"10CFR Part 21, Reportable Condition, Safety Limit MCPR Evaluations."

dated May 24,1996 l

j 3) General Electric Nuclear Energy Document l NEDE-24011-P-A-11," General Electric Standard Application for Reactor Fuel (GESTAR II),"

dated November,1995

4) General Electric letter to Detroit Edison, l " Fermi 2 Cycle 6 Safety Limit MCPR l Results," dated August 23,1996

Subject:

Proposed Technical Specification Change (License Amendment)- l Safety Limit - Minimum Critical Power Ratio (MCPR)

Pursuant to 10CFR50.90, Detroit Edison hereby proposes to amend Operating License NPF-43 for the Fermi 2 plant by modifying Technical Specification Sections i 2.1.2 and 3.4.1.1a.l.d.

This application proposes to change the Minimum Critical Power Ratio Safety Limits (SLMCPRs) in Technical Specification (TS) 2.1.2 to reflect results of a cycle-specific calculation performed for Fermi 2 operating Cycle 6 expected to commence in )

November of 1996. The application also proposes to delete the specific SLMCPR I value from TS 3.4.1.1a.l.d, referring to TS 2.1.2 for this value.

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As discussed in Reference 2, the General Electric fuel type generic values of the MCPR Safety Limits may be nonconservative for certain fuel and core designs.

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. l USNRC September 5,1996 NRC-96-0075 Page 2 General Electric performed a cycle specific calculation confirming the MCPR Safety Limits for Fermi 2 which has resulted in an increase in the required MCPR Safety Limits. While the Cycle 6 transient analysis is still in progress,it is not anticipated that any additional changes to Technical Specifications will be required as a result of j these changes to the Safety Limits.

l The description and evaluation of the changes are included in Attachment I to this l letter. Attachment 2 shows the proposed Technical Specification revisions and Attachment 3 contains the retyped Technical Specification pages. Attachment 4 contains the General Electric Nuclear Energy (GENE) letter to Detroit Edison dated I August 23,1996 containing the Cycle 6 SLMCPR values.

Detroit Edison has evaluated the proposed Technical Specification change against the criteria of 10CFR50.92 and determined that No Significant Hazards Consideration is involved. The Fermi 2 Onsite Review Organization has approved and the Nuclear Safety Review Group has reviewed the proposed Technical Specification and concurs with the enclosed determinations. In accordance with 10CFR50.91, Detroit Edison is providing a copy of this letter to the State of Michigan.

Prompt review of this application is requested because the proposed amendment is needed to support Operating Cycle 6 fol!owing the refueling outage. No  !

commitments are made in this letter. If you have any questions, please contact Mr.

Joseph Conen at (313) 586-1960.

Sincerely, Attachments cc: A. B. Beach M. J. Jordan A. J. Kugler A. Vegel Supervisor, Electric Operators, Michigan Public Service Commission, J. R. Padgett i

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1 USNRC September 5,1996 NRC-96-0075 Page 3 I, DOUGLAS R. GIPSON, do hereby affirm that the foregoing statements are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.

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I DOUGLASh. GIPSON Senior Vice President  :

On this day of t d[N1996 before me personally appeared Douglas R. Gipsoi, deing first duly sworn and says that he executed the foregoing as his free act and deed.

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Attachment 1 to NRC-96-0075 Pagei I

ATTACIIMENT I DESCRIIYI' ION AND EVALUATION OF PROPOSED TECIINICAL SPECIFICATION CIIANGE TO MINIMUM CRITICAL POWER RATIO SAFETY LIMITS l

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Attachment I to NRC-96-0075 Page 2 INTRODUCTION Detroit Edison requests that the Technical Specifications (TS) contained in Appendix A to the Fermi 2 Operating License NPF-43 be amended to revise TS Section 2.1.2 to reflect changes in the Safety Limit Minimum Critical Power Ratios (SLMCPRs) and to revise ACTION Statement 3.4.1.la.l.d to refer to TS 2.1.2 for SLMCPR values instead of including any numeric SLMCPR value. This License Change Application provides a discussion and description of the proposed TS changes, a safety assessment of the proposed TS changes,information supporting a finding of No Significant Hazards Consideration and information supporting an Environmental Assessment.

DISCUSSION AND DESCRIPTION OF THE PROPOSED CHANGE The proposed change involves revising the SLMCPRs contained in Section 2.1.2 and 3.4.1.1 of the Detroit Edison Fermi 2 TS. In the course of calculating a cycle-specific SLMCPR for another utility, it was determined that the GESTAR II (" General Electric Standard Application for Reactor Fuel," NEDE-24011-P-A-11, and U. S.

Supplement, NEDE-24011-P-A-11-US, November 17,1995) fuel type generic SLMCPR may be non-conservative when applied to some core and fuel designs. The U. S. Nuclear Regulatory Commission (USNRC) was informed of this condition in a telephone call by GE on March 27,1996, and it was the subject of a 10 CFR Part 21 notification from GENE dated May 24,1996 (Reference 2). The SLMCPR values were confirmed for current operating Cycle 5 in a letter from GENE to Detroit Edison," Safety Limit MCPR Calculation - Update" dated May 3,1996.

GENE's calculation of the revised plant-specific SLMCPR value for Fermi 2 Cycle 6 is based upon NRC approved methods (" General Electric Standard Application for Reactor Fuel," NEDE-24011-P-A-11, and U. S. Supplement, NEDE-24011-P-A US, November 17,1995) and interim implementing procedures, which have been discussed between GENE and the NRC during their meetings with the NRC staff on April 17,1996 and May 6 through 10,1996. The implementing procedures incorporate cycle-specific parameters into the analysis which include: 1) the actual core loading,2) conservative variations of projected control blade patterns, 3) the actual bundle parameters, and 4) the full cycle exposure range. As documented in Attachment 4, this calculation resulted in SLMCPR values of 1.09 and 1.11 (single loop operation). Detroit Edison has reviewed the calculation, including the selected cycle-specific input.

Therefore, Detroit Edison proposes that the Fermi 2 Plant TS Section 2.1.2 be revised to reflect the change in the SLMCPRs and ACTION Statement 3.4.1.1 be revised to refer to TS 2.1.2 for SLMCPR values.

Attachment I to i NRC-96-0075 i Page 3 EVALUATION 1 The proposed TS change will revise the Technical Specifications to reflect the change in the SLMCPRs due to the plant specific evaluation performed by GENE for Fermi  ;

2. The new SLMCPRs are calculated using NRC approved methods (" General Electric Standard Application for Reactor Fuel," NEDE-24011-P-A-11, and U. S.

Supplement, NEDE-24011-P-A-11-US, November 17,1995) and interim implementing procedures as discussed during the GENE meetings with the NRC on April 17,1996 and May 6 through 10,1996. The interim procedures incorporate plant cycle-specific parameters which include: 1) the actual core loading,2) conservative variations of projected control blade patterns,3) the actual bundle parameters, and 4) the full cycle exposure range. Attachment 4 discusses how actual core loading and bundle parameters are used as well as the selection of control blade patterns and cycle exposure points.

The fuel cladding integrity Safety Limit is set such that no mechanistic fuel damage is calculated to occur if the limit is not violated. Since the parameters which result in fuel damage are not directly observable during reactor operation, the thermal and hydraulic conditions resulting in a departure from nucleate boiling have been used to mark the beginning of the region where fuel damage could occur. Although it is recognized 6at a departure from nucleate boiling would not necessarily result in damage to BWR fuel rods, the critical power at which boiling transition is calculated to occur has been adopted as a convenient limit. However, the uncertainties in monitoring the core oper~.ing state and in the procedures used to calculate the critical power result in an uncer.ainty in the value of the critical power. Therefore, the fuel cladding integrity Safety Limit is defined as the CPR in the limiting fuel assembly for which more than 99.9% of the fuel rods in the core are expected to avoid boiling transition considering the power distribution within the core and all uncertainties )

The new SLMCPRs at Fermi 2 are 1.09 and 1.11 (single loop operation). 3 1

SIGNIFICANT H AZARDS CONSIDERATION In accordance with 10CFR50.92, Detroit Edison has made a determination that the proposed amendment involves no significant hazards considerations. To make this determination, Detroit Edison must establish that operation in accordance with the proposed amendment would 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.

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Attachment I to NRC-96-0075 Page 4 l

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1. The proposed TS changes do not involve a significant increase in the I probability or consequences of an accident previously evaluated.

The derivation of the revised SLMCPRs for Fermi 2 for incorporation into the TS, and its use to determine cycle-specific thermal limits, have been performed J using NRC-approved methods. Additionally, interim implementing procedures, l which incorporate cycle-specific parameters, have been used which result in a more restrictive value for SLMCPR. These calculations do not change the method of operating the plant and have no effect on the probability of an accident initiating event or transient.

The basis of the MCPR Safety Limit is to ensure that no mechanistic fuel damage is calculated to occur if the limit is not violated. The new SLMCPRs preserve the existing margin to transition boiling and the probability of fuel damage is not increased.

Therefore, the proposed TS change does not involve an increase in the probability or consequences of an accident previously evaluated.

2. The proposed TS changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed changes result from analysis of the Cycle 6 core reload using the same fuel types as previous cycles. These changes do not involve any new method for operating the facility and do not involve any facility modifications.

No new initiating events or transients result from these changes. Therefore, the proposed TS change does not create the possibility of a new or different kind of accident, from any accident previously evaluated.

3. The proposed TS changes do not involve a significant reduction in a margin of safety.

The margin of safety as defined in the TS Bases will remain the same. The new SLMCPRs are calculated using NRC-approved methods which are in  ;

! accordance with the current fuel design and licensing criteria. Additionally, l interim implementing procedures, which incorporate cycle-specific parameters, l have been used. The MCPR Safety Limit remains high enough to ensure that j greater than 99.9% of all fuel rods in the core will avoid transition boiling if the '

j limit is not violated, thereby preserving the fuel cladding integrity. Therefore, the proposed TS change does not involve a reduction in a margin of safety.

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Attachment I to NRC-96-0075 Page 5 ENVIRONMENTAL IMPACT Detroit Edison has reviewed the proposed Technical Specification changes against the criteria of 10CFR51.22 for environmental considerations. The proposed changes do not involve a significant hazards consideration, nor significantly change the types or increase the amounts of effluents that may be released offsite, nor increase individual or cumulative occupational radiation exposures. Based on the foregoing, Detroit Edison concludes that the proposed Technical Specifications meet the criteria given in 10CFR51.22(c)(9) for a categorical exclusion from the requirements for an Environmental Impact Statement.

CONCLUSION ,

Based on the evaluations above: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and the proposed amendment will not be inimical to the common defense and security or the health and safety of the public.

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