ELV-00868, Submits Addl Info & Clarification of 890717 Response to NRC Request Re Application for Amend to Licenses NPF-2 & NPF-8. Util Has Determined More Appropriate to Ack Conservatism in Core Fission Product Inventories Due to Core Average Burnup

Submits Addl Info & Clarification of 890717 Response to NRC Request Re Application for Amend to Licenses NPF-2 & NPF-8. Util Has Determined More Appropriate to Ack Conservatism in Core Fission Product Inventories Due to Core Average Burnup

ML20248B763
Person / Time
Site:	Vogtle
Issue date:	09/25/1989
From:	Hairston W GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
ELV-00868, ELV-868, TAC-73595, TAC-73596, NUDOCS 8910030279
Download: ML20248B763 (3)

Text

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• 8 4 Georg.a Power C7r.pany

. 333 Ptedmont Averac Atlania. Geora.o 30338 Telephone 404 5?6-3195 Maeng Addrea 40 invemess Center Pahap Post 015ce Box 1295 B,rrn:ngharn. Alanama 35201 Telepncne 205 F168 5581 tw w w t w inc n % e W. G. Hairston, lil Senior Vice Prescent Nuclear operatons ELV-00868 1645n Docket Nos. 50-424 50-425 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentlemen:

V0GTLE ELECTRIC GENERATING PLANT REVISION TO TECHNICAL SPECIFICATION 5.3.1 SUPPLEMENTAL INFORMATION By letter ELV-00511 dated June 12, 1989 Georgia Power Company (GPC) proposed to amend the Vogtle Electric Generating Plant (VEGP) Units 1 and 2 Technical Specifications, Appendix A to Operating Licenses NPF-68 and NPF-81. The proposed amendment revises the allowable reload fuel enrichment from 3.5 to 4.55 weight percent U-235. The NRC noted that the use of the higher enrichment fuel would allow increased burnup and requested that GPC address the environmental consNerations of increased burnup in conjunction with the request for the Technical Specification change.

In response to this request GPC provided supplemental information in its letter ELV-00696 dated July 17, 1989. That letter noted that the batch average burnup of fuel to be discharged at the end of Cycle 3 will be higher than the 33,000 MWD /MTU assumed in 10 CFR 51.52 and requested a categorical exemption from 10 CFR 51.52. In support of this request, GPC provided an evaluation to demonstrate that the higher burnup expected for Cycle 3 of VEGP Unit 1 does not involve any significant hazards considerations. The purpose of this letter is to provide additional information and clarification regerding the content of our previous letter ELV-00696, 10 CFR 51.52 (a)(3) states "The average level of irradiation of the irradiated fuel from the reactor does not exceed 33,000 megawatt-days per metric ton...". The basis of our previous letter was that the fuel to be discharged 1 at the j of Cycle 3 of VEGP Unit 1 would exceed 33,000 MWD /MTV. However, it I should also have been noted that the average irradiation of all irradiated I fuel discharged f rom the reactor will remain less than 33,000 MWD /MTU.

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Georgia Powerkn U. S. Nuclear Regulatory Commission ELV-00868 Page Two In support of the evaluation to demonstrate that the increased burnup associated with Cycle 3 does not involve any significant hazards considerations it was stated that the batch average burnup for fuel to be discharged at tne end of Cycle 3 will be less than the maximum batch average burnup of approximately 36,000 MWD /MTU used in developing the core fission product inventories for the safety analyses presented in Chapter 15 of the VEGP Final Safety Analysis Report.

A batch of fuel as used in our letter to define batch average burnup, refers to those fuel assemblies having the same enrichment and same initial loading i date. Using this definition of batch to calculate batch average discharge j burnup results in our previously submitted value of 35,000 MWD /MTV. If batch j average burnup i:, defined as the average of the burnup of all fuel assemblies  ;

in the quantity of fuel to be replaced at the end of the Cycle 3, the value  !'

will be approximately 37,000 MWD /MTV.

Core fission product inventories, given in table 15A-3 of the FSAR, are based on a three region equilibruim cycle core at end of life and assumes that the three regions have operated at a specific power of 40.03 MW/MTU for 300, 600 and 900 EFPDs, respectively, for a core average burnup of approximately 24,000 MWD /MTU. The core average burr,ap of VEGP Unit 1 at the end of Cycle 3 is anticipated to be in the range of 29,000 to 30,000 MWD /MTU. Since the primary concern of the change is related to increased burnup, only burnup was previously discussed in the significant hazards evaluation. It should have also been noted in the significant hazards evaluation that VEGP operates at a specific power of approximately 38.4 'WMTU at 100% rated thermal power, compared to the 40.03 MW/MTU used for FSAR table 15A-3. This conservatism more than compensates for any effects of the burnup increase, and represents significant conservatism when compared to the relatively small effects of increased burnup associated with Cycle 3 of VEGP Unit 1.

Due to the differences in the way the batch average burnup presented M our previous letter was defined and the way the burnup was defined for the j development of table 15A-3, GPC has determired that it is more appropriate to '

acknowledge the conservatism in core fission product inventories due to the actual operating specific power level versus the conservative 40.03 MW/MTU specific power level. This is because increasing core average burnup has a smaller secondary effect on core fission product inventory for figure 15A-3 than differences in specific operating power level . VEGP is not increasing I the specifdc operating power level, therefore, the conclusion that the  !

increase in burnup associated with Cycle 3 of VEGP fnit 1 does not involve a '

significant hazards consideration remains valid. 4 Sincerely, y). .

A -

W. G. Hairston, III WGH,III/HWM/gm xc: (see next page)

ee .

Georgia Power 41

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U. S. Nuclear Regulatory Commission l ELV-00868 Page Three xc: Georgia' Power Company Mr. C. V '. McCoy Mr. G. Lockhold, Jr.

Mr. R. M. Odom Mr. P. D. Rushton NORMS Southern ~ Company Services Mr. L. B. Long Mr. J. L. Leamon U. S. Nuclear Regulatory Commission ik. S. D. Ebneter, Regional Administrator Mr. J. B. Hopkins, Licensing Project Manager, NRR Mr. J. F. Rogge, Senior Resident Inspector, Vogtle l I i

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