ML20247H761

Safety Evaluation Supporting Amends 100 & 82 to Licenses NPF-9 & NPF-17,respectively

ML20247H761
Person / Time
Site:	Mcguire, McGuire
Issue date:	07/18/1989
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20247H748	List: ML20247H746 ML20247H751 ML20247H761
References
NUDOCS 8907310123
Download: ML20247H761 (4)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.100TO FACILITY OPERATING LICENSE NPF-9 AND AMEt;DMENT NO. 82 TO FACILITY OPERATING LICENSE NPF-17 DUKE POWER COMPANY DOCKET NOS. 50-369 AND 50-370 MCGUIRE NUCLEAR STATION, UNITS I AND 2

1.0 INTRODUCTION

By letter dated January 22, 1989, as supplemented May 17, 1989, Duke Power i Company (the licensee) proposed amendments to the operating licenses for McGuire Nuclear Station, Units 1 and 2 to change the Technical Specification (TS). The proposed changes would update pressure und temperature (P-T) limits in TS 3/4.4.9 for heatup and cooldown of the reactor coolant system, including

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essociated TS Table 4.4-5 on the withdrawal and examination schedule for reactor vessel material irradiation surveillance specimens. TS Bases 3/4.4.9 would be similarly updated to reference revised heatup and cooldown curves and information associated with their derivation and use.

Because the May 17 and June 19, 1909, submittals clarified or corrected certain aspects of the original submittal, the substance of the changes noticed in the Federal Pegister and the proposed no significant hazards determination were not affected.

2.0 EVALUATION

a. McGuire Unit 1 Heatup and Cooldown Curves for McGuire Unit 1, these ainendments replace the existing reactor coolant system (RCS) heatup and cooldown curves, referenced by i TS 3/4.4.9.1, with new curves shown on TS Figures 3.4.2 and 3.4-4, respectively. As before, the new curves contain margins of 10' F ar.d 60 psig for possible instrument errors, and are applicable for the service period up to ten effective full power years (EFPY). The new curves are based upon a Westinghouse Report, "McGuire Unit 1 Reactor Vessel Heatup and Cooldown Limit Curves for Normal Operation" dated November 1988 and forwarded as Attachment 5 of the licensee's January 22, 1989 submittal. The method for predicting radiation embrittlement (i.e. , determination of adjusted reference temperature for vessel beltline material) in this Westinghouse report is based upon Regulatcry Guide (RG) 1.99, Revision 2. The associated maximum L heatup or cc01down rate during normal operations as specified by TS l

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3.4.9.la and TS 3.4.9.lb, respectively, is decreased from 100* F per hour.to 60* F per hour. Duke's own associated administrative cooldown limit is not affected by these amendments and continues to be 50" F per hour.

The new RCS heatup and couldown curves for McGuire Unit I are needed because the existing TS limits, based on analysis of surveillance Capsule U as documented in the licensee's letter of April 5,1985 and Westinghouse Report WCAP-10786, are valid up to 4.86 EFPY. At the end of fuel cycle 5 (October 1988), McGuire Unit I had reached about 4.3 EFPY and was projected to reach the existing limit by about Jurie 1989. Thus, absent this anendment, the existing Unit I heatup l and cooldown P-T limits would become non-conservative about mid-1989.

The licensee also notes that the new Unit 1 operating limits are intended to apply for a limited period of time. During the end of l

fuel cycle 5 refueling outage (October - December 1988), Capsule X was removed from the Unit i vessel for analysis and for development of new P-T limit curves using RG 1.99, Revision 2. Pursuant to l 10 CFR 50, Appendix H, results of analysis of this capsule will be provided to the NRC in late 1989 (i.e., within one year of removal of the capsule). The licensee will propose amendments to incorporate the resulting operating limits into the _TS shortly thereaf ter.

The staff has reviewed the P-T limits and curves for McGuire Unit 1, including the November 1988 Westinghouse report. We find that the fracture-toughness properties of the ferritic material in the reactor coolant pressure boundary have been determined in accordance with Standard Review Plan Chapter 5.3.2 and that the approach defined in Appendix G to the ASME Code Section III was followed to calculate the allowable limit curves for heatup and cooldown rates. Accordingly ,

since the new curves are based on results of capsule analyses perforned with NRC approved methods, and since the new curves are conservative with respect to the existing P-T operating limits, we find that they appropriately reflect the change in material toughness of the reactor vessel due to irradiation effects and are acceptable.

b. McGuire Unit 2 Heatup and Cooloown Curves For McGuire Unit 2, these amendments replace the existing RCS heatup and cooldown curves with new curves shown on TS Fi9ures 3.4-3 and 3.4-5 respectively. The new curves are needed to reflect adjustments to existing limits based upon analysis of the last surveillance capsule removed from the Unit 2 vessel. Results of the analysis of this last capsule, Capsule V, were provided by the licensee's letter of April 2,1986 and by WCAP-11029. As before, the new curves  ;

contain margins of 10 F and 60 psig for possible instrument errors.

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l The new curves are proposed to be applicable only for the first 8 EFPY.

The curves provided in WCAP-11029 were developed using Revision 1 to RG 1.99. As with Unit I curves, the associated maximum heatup or cooldown rate during normal operations as specified by TS 3.4.9.la and TS 3.4.9.lb, respectively, is decreased from 100* F per hear to 60" F per hour, which is more in line with Duke's own administrative cooldown limit of 50 F per hour.

The licensee notes that the new Unit 2 operating limits are intenoed to apply for a limited period of time. During the end of fuel cycle 5 refueling outage (July - September 1989), Capsule X will be removed from the Unit 2 vessel for analysis and for development of new P-T limit curves using RG 1.99, Revision 2. Pursuant to Appendix H of 10 CFR 50, results of analyses of this capsule will be provided to the NRC during the third quarter of 1990. The licensee will propose amendments to incorporate the resulting operating limits into the TS shortly thereafter.

On July 12, 1968 the Commission issued Generic Letter (GL) 68-11 "NRC Position on Radiation Embrittlement of Reactor Vessel Materials and Its Impact on Plant Operations," forwarding Revision 2 to RG 1.99 and -

noting that it would be used to review P-T limits and embrittlement analy ses. The Connission stated that all actions (hardware, procedures, and/or staff modifications) resulting from the use of Revision 2 should be completed (fully implemented and. operational) within two refueling outages (approximately 3 years) after the effective date of Revision 2 to RG 1.99. Using Revision 2 and the surveillance data reported in WCAP-11029, we find that the proposed P-T limits contain sufficient margin to account for neutron irradiation damage through 5 EFPY.

McGuire Unit 2 has presently achieved 4.1 EFPY (June 1989) and is conservatively projected to reach 5 EFPY no sooner than the end of fuel cycle 6 (August - November 1990). On this basis, we find use of the Unit 2 P-T curves acceptable until completion of the refueling outage at the end of Unit 2 fuel cycle 6. Moreover, no waiver of the implemen-tation requirement for Revision 2 of RG 1.99 is implied or intended by these amendments.

c. Revised Capsule Withdrawal Schedule These amendments update TS Table 4.4-5, " Reactor Vessel Material Surveillance Program - Withdrawal Schedule," reflecting separate withdrawal schedules for Unit I and Unit 2 capsules, and consistent with the above discussions, denoting the previous removal of Unit 1

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Capsules U and X and Unit 2 Capsule V. The associated lead factors l in the table are also updated. The lead factors represent the i relationship between the fast neutron flux density at the capsule I location and the inner wall of the pressure vessel and are used (

along with the capsule withdrawal time to predict future radiation damage to the pressure vessel material (The heatup and cooldown {

curves are recalculated when the change in nil-ductility reference temperature (ART exceed f r the equivalent capsuleradiatioNDIx)posure).sthecalculatedARTTheserevisionstUD[hetableaj 1 upon information provided by Westinghouse in Section 7 of WCAP-10786 for McGuire Unit 1 and in WCAP-11029 for McGuire Unit 2. )

i The NRC staff has reviewed the revisions to TS Table 4.4-5 and finds that they are in accordance with the requirements of ASTM E 185-82 and l 10 CFR 50, Appendix H, and are, therefore, acceptable.

3.0 ENVIRONMENTAL CONSIDERATION

l These amendments involve changes to the installation or use of facility com-ponents located within the restricted area as defined in 10 CFR Part 20. 1 The staff has determined that the amendments involve 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 exposure. The NRC staff has made a determination that the amendments involve no significant hazards consideration, and there has been no public comment on such finding. Accordingly, the amendments meet 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 assessment need be prepared in connection with the issuance of these amendments.

4.0 CONCLUSION

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The Commission made a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register (54 FR 13763) on April 5, 1989. The Commission consulted with the state of )

l North Carolina. No public comments were received, and the state of North l Carolina did not have any comments. '

We have 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, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: D. Hood, PD#II-3/DRP-I/II Dated: July 18,1989  !

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