ML20149K034
| ML20149K034 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 02/03/1988 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | GEORGIA POWER CO. |
| Shared Package | |
| ML20149K037 | List: |
| References | |
| TAC-66471, NUDOCS 8802230333 | |
| Download: ML20149K034 (3) | |
Text
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4 7590-01 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of GEORGIA POWER CCMPANY 1
OGLETHORPE POWER CORPORATION ML'NICIPAL ELECTRIC AUTHORITY OF GEORGIA Docket No.
50-366 CITY OF DALTON, GEORGIA Edwin 1. Hatch Nuclear Plant, Unit 2 EXEMPTION j
I.
Georgia Power Company, et 31., (the licensee) is the holder of Facility Operating License No. NPF-5, which authorizes full power operation of the Edwin I. Hatch Nuclear Plant, Unit 2.
The license provides, among other things, that it is subject to all rules, regulations and Orders of the Nuclear Regulatory Comission (the Ccemission) now or hereafter in effect.
The facility incorporates a boiling water reactor at the licensee's site j
located in Appling County, Georgia.
II.
By letter dated January 6,1988, the licensee requested an exeeption from the requirements of 10 CFR Part 50.62(c)(4), wnich establishes the minimum in-jection flow rate and the boron concentration for the standby liquid control system (SLCS).
Specifically, 10 CFR Part 50.62(c){4) requires that each boiling water reactor nest have a SLCS with minisom flow capacity and boron content eouiv-alent in control capacity to 86 gallons per minute (GPM) of 13 weight percent (w/o) sodium pentaborate solution. The licensee requested an exemption from P
1 1
2 this requirement to permit use of a minimum flow rate of 41.2 GPM and an avail-able sodium pentaborate concentration ranging from 6.2% to 13 w/o depending on the volume in the existing SLCS storage tank.
The Boron-10 centent of the boron in the dissolved sodium pentaborate solution would be enriched to 60 atomic percent.
The requirement established by the regulation was intended to provide for prorpt injection of negative reactivity into a boiling water reactor pressure l
vessel in the event of an anticipated transient without scram (ATWS) event.
The reactor vessel size used to establish the required flow rate of 86 GPM and the sodium pentaborate concentration of 13 w/o was the large 251-inch diameter vessel used in the BWR/5 and BWR/6 designs.
The Hatch Unit 2 reactor has a much smaller 218-inch diameter vessel.
For the Hatch Unit 2 reactor, a lesser flow rate, follcwing the formula proposed by the licensee, will provide a negative reactivity injection in an ATWS event equivalent to that called for by the regulation for the larger 251 inch diameter boiling water reactor vessel.
See Generic Letter 85-03, "Clarification of Equivalent Control Capacity for Standby Liquid Control Systems " January 28, 1985.
.i In this case, the flow rate-boron 10 concentration relationship established by the licensee's forrula will provide control capacity for the smaller Hatch Unit 2 reactor pressure vessel equivalent to that called for by the rule based en larger reactor pressure vessels. Requiring Hatch Unit 2 to have the flow I
rate-boren 10 concentration capacity specified by the rule is not necessary to 2
provide adequate negative reactivity in the event of an ATWS at Hatch Unit 2.
l Thus, the Commission's staff finds that there are special circumstances in this
l
~:
j i
-3 case which satisfy the standards of 10 CFR Part 50.12(a)(2)(ii). As set forth in the Safety Evaluation of Anendment No. 90, issued concurrently with this Exemption, the staff has detemined that operation under the revised Technical Specifications governing flow rate and boron-10 concentration will not endangar public health and safety and will not be inimical to the cosinon defense and security.
IV.
Accordingly, the Comission has detemiaed that pursuant to 10 CFR Part 50.12, an exemption is authorized by law and will not present an undue risk to the public health and safety, and is consistent with the comon defense and security, and hereby grants the following exerrotion with respect to the requirenents of paragraph (c)(4) of 10 CFR Part 50.62.
The licensee may operate the facility with flow rate and baron concen-tration requirements as set; forth in Sections 3.1.5 and 4.1.5 of the Hatch Unit 2 facility Technical Specification.
Pursuant to 10 CFR Part 51.32, the Comission has detemired that granting this Deeption will have no significant irpact on the environnent (53 FR 2659).
This penption is effective upon issuance.
FOR THE NUCLEAR REGULATORY CCM ISSION Steven A. Yarga, Director Division of Reactor Projects I/II Dated at Rockville, Maryland, th d day of February 1988 gt, FD(!!-3/DRP-!/II
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