ML20217J563

Safety Evaluation Supporting Amend 225 to License DPR-56

ML20217J563
Person / Time
Site:	Peach Bottom
Issue date:	10/09/1997
From:	NRC (Affiliation Not Assigned)
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ML20217J548	List: ML20217J545 ML20217J557 ML20217J563
References
NUDOCS 9710210181
Download: ML20217J563 (3)

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. a na g* k UNITED STATES i" j t

NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20666 0001 4, ,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.225 TO FACILITY OPERATING LICENSE NO. DPR-56 PECO ENERGY COMPANY PUBLIC SERVICE ELECTRIC AND GAS COMPRi1 DELMARV?. POWER AND LIGHT COMPANY ATLANTIC CITY ELECTRIC r.0MPANY PEACH BOTTOM ATOMIC POWER STATION. UNIT NO. 3 DOCKET NO. 50-278

1.0 INTRODUCTION

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By letter dated June 30, 1997, as supplemented by letter dated September 26, 1997, the PECO Energy Company (PECO, the licensee) submitted a request for changes to the Peach Bottom Atomic Power Station (PBAPS), Unit No. 3 Technical Specifications (TSs). The License Change Application (LCA) ECR 03620 supersedes LCA ECR 96-02609, submitted on October 30, 1996. The requested changes would replace the generic General Electric (GE) 13 minimum critical power ratio (MCPR) safety limits with Peach Bottom cycle-specific MCPR safety limits, using core-specific input parameters. The thermal limits are evaluated using NRC-approved methodology specified in the licensing basis

, topical report, GESTAR II (Amendment 22). The GESTAR II delineates, in part, that: (1) for every new fuel design, a generic MCPR will be calculated using a high power density core, assuming a bounding equilibrium core: (2) the plant-specific MCPR safety limit will be evaluated to confirm that it is bounded by the generic MCPR safety limit; and (3) the critical power correlation will be reconfirmed, or a new one establishod, whennver there is change in the wetted parameters of the flow geometry (i.e fuel, water rod diameter, channel sizing, spacer design.) The supplemental letter provided clarifying information that did not change the original no significant hazards consideration determination.

For the new part length GE13 fuel, General Electric Nuclear Energy determined the generic MCPR safety limit is 1.09. However, GE performed a cycle-specific MCPR safety limit analysis for PBAPS, Unit 3, and determined that the cycle-specific MCPR safety limits bound the generic GE13 MCPR safety limits.

Consequently, in this amendment, PECO proposes to revise TS Section 2.1.1.2 and to adapt the cycle-specific MCPR safety limit. The MCPR safety limit will change from 1.07 to 1.11 for two recirculation loops in operation and from 1.08 to 1.12 for a single recirculation loop in operation.

2.0 EVALUATION PECO stated that the core-specific safety limits were evaluated in accordance witi: the NRC-approved methodology specified in the topical report, " General Electric Standard Application for Reactor Fuel" (NEDE-240ll-P-A-13, dated August 1996), and supplemented by " Proposed Amendment 25 to GE Licensing 97102101G1 971009 DR ADOCK 0500 8

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2-l on Cycle Specific Safety Limit L . TopicalThe-pro MCPR." = report NEDE-24011-P-A-( GES1AR II)d the corresponding evaluatio

provided-below. posed changes to tha-TSs an ,

j Proposed Change - Specification 2.1.1 - Reactor Ct,re Safety Limits (SLs) and Administrative Controls 5.6 - Reporting Requirements l

F PEC0 proposes to change the safety limit MCPR in TS 2.1.1.2 from 1.07 to 1.11 i for two recirculation loop operation, and from 1.08 to 1.12 for single loop

! operation.

1-i The staff reviewed both the-amendment application and the June 16,1997, GE letter provided as Attachment I to the amendment request. The GE letter that discusses the basis for the Peach Bottom, Unit 3, cycle-specific MCPR safety i . limit, including the mixed core-specific input parameters, the corresponding l assumptions and the reasons the cycle-specific MCPR safety limits calculations

- yield higher values than the generic GE 13 core MCPR safety limits.

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The staff reviewed the R-factor calculation method for the GE13 fuel product line, and other relevant information provided in both the June 16. 1997, GE l 1etter and Amendment 25 to the topical report GESTAR II, which is under staff .

i* review. The proposed cycle-specific MCPR analysis is based on the NRC-approvod methodologies specified in GESTAR II (NEDE-240ll-P-A-13, Sections

, 1.1.5 and 1.2.5, which references NED0-10985-A, January 1977), for two-loop-L operation. Because the- R-factor methodology referenced in NEDE-240ll-P-A-13

! is not applicable to the part length GE13 fuel, a revised R-factor methodology i described in the November 1995 NEDC-32505P, "R-Factor Calculation Method for

Gell, GE12 and GE13 Fuel," was used. The revised R-factor calculation method

! - uses the same NRC-approved equation stated in GESTAR (NEDE-240ll-P-A), except

! - that it substitutes rod integrated powers for the lattice peaking factors to

? account for the effects nf the part length rod design. This method is

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acceptable for use at PBAPS.

l- The PBAPS, Unit 3, cycle-specific MCPR safety limit was derived using

! cycle-specific fuel and core parameters including the actual core loading, i conservative variations of projected control blade patterns, the= actual bundle F parameters, and the cycle exposure range. The key parameters for the MCPR i safety limit calculations identified by GE indicate that the core-specific MCPR is based on flatter radial power distribution than the generic GE13-calculations. The PBAPS, Unit 3, core also has higher core enrichment for i- Cycle 12, and the MCPR evaluation also covered a different range of cycle

- exposure. The flatter radial power distribution, the higher core enrichment

- and.the different state points of cxposure cycle used in the MCPR evaluation j all contributed to the higher core-specific MCPR safety limits.

Based on the review, the staff approved the proposed changes to j Section 2.1.1.2 of the PBAPS TSs, because the MCPR safety limits: (1) are based on core-specific inputs and analysis; (2) were obtained using i NRC-approved methodology; and (3) provide higher margins of safety to ensure that- 99% of the rods in the-core will not experience the boiling transition during normal operation, or anticipated operational occurrences. Since the MPR safety limits were derived using cycle-specific inputs and parameters, 4

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this amendment applies only to the Cycle 12 reload. The staff finds'the amendment request for the Cycle 12 reload to be acceptable.

A footnote is added to TS 2.1.1.2, " Reactor Core sLs," on page 2.0.1 to specify that the MCPR values apply only to Cycle 12. This will ensure that the MCPR value is reconfirmed for subsequent cycles. Section 5.6.5.b of the TS references NRC-approved documents that provide the analytical methods used to determine the cote operating limits. A footnote is being added to T3 5.6.5.b.1 or, page 5.0-21, which states that for Cycle 12, s)ecific documents were approved in the NRC's safety evaluation that support tie license amendment to revise the MCPRs. This footnote change is to reflect the approveG .tse of the R-Factor Calculation Method, and will ensure the values for cycle-specific parameters will be determined such that applicable limits of the safety analysis are met. Therefore, the proposed changes are acceptable.

3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendment. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC 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 exposuce. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (62 FR 43373). The amendment also relates to changes in recordkeeping, reporting, or administrative procedures or requirements. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) and (10). Pursuant to 10 CFR 51.22 need be prepa(b) no environmental impact statement or environmental assessment red in connection with the issuance of the amendment.

5.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1)-there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: A. Abdullahi Date: October 9, 1997 e

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