ML20214Q973
| ML20214Q973 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 05/28/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20214Q963 | List: |
| References | |
| TAC-64778, NUDOCS 8706050284 | |
| Download: ML20214Q973 (4) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION 7;
j WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE.0F. NUCLEAR REACTOR REGULATION
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SUPPORTING AMENDMENT NO. 138TO t
FACILITY OPERATING LICENSE DPR-57 GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MUNICIPAL ELEGIRIC AUTHORI1Y OF GEORGIA i
CITY OF DALION, GEUHGIA EDWIN I. HATCH NUCLEAR PLANT, UNIT 1 l
DOCKET NO. 50-321 INTRODUCTION By letter dated February 6,1987 (Reference 1), Georgia Power Company (the licensee) proposed changes to the Hatch Plant Unit 1 Technical Specifications (TSs)thatwould: (1) reduce the limits on the Standby Liquid Control System (SLCS) sodium pentaborate solution concentration versus volume and concen-tration versus temperature to reflect the use of sodium pentaborate that has been enriched in Baron-10; (2) reduce the minimum acceptable SLCS pump flow rate from 43 to 41.2 gallons per minute (gpm) in order to conform with the 41.2 gpm minimum acceptable flow rate for Hatch Unit 2; and (3) remove level and temperature alann setpoint values from the concentration versus volume and the concentration versus temperature limit curves. The proposed changes would result from the use of boron enriched in the isotope B-10 in the SLCS in order to meet the requirements of the Anticipated Transient Without Scram (ATWS) rule, 10 CFR 50.62.
The current Technical Specifications are based on the use of sodium pentaborate unenriched in the B-10 isotope. The pro-posed changes are to TS Figure 3.4-1 and 3.4-2, to TS 4.4.A.2.b and to Basis 3.4, all associated with the SLCS.
EVALUATION The proposed TS changes for Hatch I are intended to meet the requirements of' 10 CFR 50.62, with values chosen so that the results could also be applied to Hatch 2.
The ATWS Rule requires that the SLCS be equivalent in control capacity to a system with an 86 gpm injection rate, using 13 weight percent unenriched sodium pentaborate solution, in a system with a 251 inch diameter reactor vessel.
Of the several proposed approaches presented in the General Electric report (Reference 2), and approved in the NRC evaluation (Reference 3), GPC has chosen to use boron enriched in the B-10 isotope. Using the calculational methods of Reference 1 results in a minimum concentration of 6.2 weight percent sodium pentaborate when using an enrichment of 60 weight percent B-10, an injection flow rate of 41.2 gpm, and a water mass of 434.800 pounds. These values are (conservatively) applicable to both Hatch I and 2.
The aporoach taken for Hatch 1 and the resulting parameter values are reason-l able and acceptable.
l 8706050284 870528 PDR ADOCK 05000321 P
The changed values lead to proposed changes in the TS. This includes a change ~
from 43 to 41.2 gpm pump rate in TS 4.4.A.2.b, and changes to Figures 3.4-1 and 3.4-2 giving required sodium pentaborate (1) concentration as a function of gross volume of solvent in the tank and (2) temperature as a function of concentration.
(Unneeded alarm setpoints, used for information only, would be removed from the i
figures.) These changes are the result of straightforward calculations and are reasonable and acceptable. The related Basis 3.4 has also been changed to re-l flect the revised approach and requirements. This, too, is acceptable.
Having selected the enriched boron option of compliance with the ATWS Rule, GPC, following an approved approach, has elected to have the sodium pentaborate 3
formulated at the chemical vendor's facility. The boron enrichment test will therefore be done prior to the acceptance for use on the site.
The appropriate content of the SLCS will then be verified by monitoring the system volume, con-centration and temperature using existing TS 4.4.C surveillance requirements.
These are all acceptable procedures. They have been agreed upon as elements of an appropriate approach for compliance with the ATWS Rule in discussions between the staff and industry (BWR Owners Group ATHS Committee).
In sumary, the licensee has requested TS changes for Hatch Unit I which would provide for the use cf boron enriched in the B-10 isotope in the SLCS to meet the requirements of 10 CFR 50.62. The use of the enriched boron in the SLCS would allow the TS changes requested by the licensee without any loss of reactivity control. The approach selected by the licensee to meet the require-ments of 10 CFR 50.62 and the associated TS changes are acceptable.
ENVIRONMENTAL CONSIDERATIONS 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 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 i
increase in individual or cumulative occupational radiation exposure. The Comission has previously issued a. proposed finding that this amendment in-volves no significant hazards consideration and there has been no public coment on such finding. Accordingly, the amendment meets the eli 1j' criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9)gibility Pursuant l
to 10 CFR 51.22(b),'no environmental impact statement or environmental assess-ment need be prepared in connection with the issuance of the amendment.
CONCLUSION 4
The Comission made a proposed determination that the amendment involves no significant hazards consideration which was published in the Federal Register j
(52FR9568)onMarch 25, 1987, and consulted with the state of Georgfa. No public coments were received, and the state of Georgia did not have any comments.
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s I. 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 en-dangered by operation in the proposed manner, and (2) such activities will be i
conducted in compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
REFERENCES 1.
Letter from J. P. O'Reilly, Georgia Power Compary, to U. S. Nuclear Regulatory Commission, dated February 6,1987.
2.
" Anticipated Transients Without Scram: Response to NRC ATWS Rule, 10 CFR 50.62," NEDE-31096-P, December 1985.
3.
" Safety Evalaution nf Topical Report (NEDE-31096-P)
Anticipated Transients Without Scram: Restonse to ATWS Rule, 10 CFR 50.62',"
October 21, 1986.
~j Principal Contributors:
H. Richings L. Crocker Dated:' Hay 28, 1987 s
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4 DATED May 28, 1987 AMENDMENT NO.138TO FACILITY OPERATING LICENSE DPR-57. EDWIN I. HATCH, UNIT 1 DISTR"UTION:$[M$
(M g.
Local PDR PRC System PDf!I-3 Reading M. Duncan L. Crocker B. J. Youngblood D. Hagan T.Barnhart(4)
E. Butcher W. Jones ACRS (10)
OGC-Bethesda GPA/PA ARM /LSPB S. varga G. Lainas J. Partlow E. Jordan H. Richings 6
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