ML20149C467
| ML20149C467 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 01/28/1988 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | CAROLINA POWER & LIGHT CO. |
| Shared Package | |
| ML20149C473 | List: |
| References | |
| NUDOCS 8802090164 | |
| Download: ML20149C467 (5) | |
Text
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l 7590-01 UNITED STATES NUCLEAR REGULATOP,Y COMMISSION In the Matter of
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CAROLINA POWER & LIGHT COMPANY Docket No. 50-324 (Brunswick Steam Electric Plant,
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Unit 2)
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EXEMPTION I.
Carolina Power & Light Company (the licensee) is the holder of Facility Operating License No. DPR-62, which authorizes operation of the Brunsuick Steam Electric Plant, Unit 2 (Brunswick or the facility). The license provides, among other things, that the facility is subject to all rules, regulations and Orders of the Nuclear Regulatory Comissjon (the Comission) now or hereafter in effect.
The facility is a boiling water reactor located at the licensee's site in Brunswick County, North Carolina.
II.
By letter dated August 17, 1987, the licensee requested an exemption from the requirements of 10 CFR 50.62(c)(4), which establishes the minimum i
injection flow rate and the boron concentration for the standby liquid control system (SLCS),
Specifically, 10 CFR 50.62(c)(4) requires that each boiling water reactor must have a SLCS with minierum flow capacity equivalent in control capacity to 86 gallons per minute (gpm) with a boron concentration of 13 8002090164 860128 ADOCKOLDQ1 PDR P
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' weight percent sodium pentaborate. The licensee requests an exemption froni this requirement to pemit use of a minimum flow rate of 60 gpa and a sodium pentaborate concentration of 13 weight percent.
The requirement established by the regulation was intended to provide for prompt injection of negative reactivity into a boiling water reactor pressure vessel in the event of an anticipated transient without scram (ATWS) event. The reactor vessel size used to establish the required flow rate of 66 gpm and the sodium pentaborate concentration of 13 weight pacent was the large 251-inch diameter vessel used in the BWR/5 and BWR/6 designs.
The Brunswick Unit 2 reactor has a much smaller, 218-inch diameter, vessel.
For the Brunswick reactor, a lesser flow rate will provide adequate shutdown marcin in an ATWS event, equivalent to that called for by the regulation for the larger 251-inch diameter boiling water reactor vessel.
Ref er to Generic Letter 85-03, "Clarification of Equivalent Control Capacity for Standby Liquid Control Systems," January 28, 1985.
III.
In this case, the injection flow rate and boron concentration will provide the equivalent level of control capacity for the st. aller Brunswick reactor pressure vessel as that called for by the rule based on larger reactor pressure vessels. Requiring Brunswick to provide the flow rate-boron concentration capacity specified by the rule would not, in these particular circumstances, serve the underlying purpose of the rule. The purpose of the rule is to reduce the risk from ATWS events by ensuring adequate shutdown margin. Thus, the Comission's staff finds that there are special
circumstances in this case which satisfy the standards of 10 CFR 50.12(a)(2)
(ii).
IV.
The licensee provided a determination that special circumstances exist under 10 CFR 50.12(a).
As discussed above, the underlying purpose of the requirements of-paragraph (c)(4) of 10 CFR 50.62 is to ensure adequate shutdown margin in an ATWS event.
The underlying purpose is achieved and served by an injection rats. of 66 gpm of 13 weight percent sodium pentaborate solution.
Accordingly, the Commission has determined that pursuant to 10 CFR 50.12(a), the Exemption, as described in Section III, is authorized by law and will net present an undue risk to the public health and safety and is consistent with common defense and security, and special circumstances are present for the Exemption, in tnat application of the regulation in these particular circumstances is not necessary to achieve the underlying purposes of 10 CFR 50.62(c)(4).
Therefore, the Commission hereby grants the Exeration from paragraph (c)(4) of 10 CFR 50.62 to allow the use of an SLCS injaction flow rate of 66 gpm of 13 weight percent sodium pentaborate solution.
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-4 Pursuant to 10 CFR 51.32, the Consnission has determined' that the cranting this Exemption will have no significant impact on the enviren1:ent (53 FR 25511. f This Exemption is effective upon iss"Jance.
FDR ThE NUCLEAR REGULATORY C0FMISS10ti f,
1 n b ga it Division-of Reactor ects I/II Office of Nuclear Reactor Regulation Dated at Bethesda, Maryland this 28t'1 day of January 1988 d
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Pursuant to 10 CFR 51.32, the Connission has determined that the granting this Exemption will have no significant iir. pact on the environment (52 FR 47777).
This Exemption is effective upon issuance.
FOR THE NUCLEAR F.EGULATORY COMMISSION
/s/
Steven A. Varga, Director Division of Reactor Projects I/II Office of Nuclear Reactor Regulation Dated at Bethesda, Maryland this 28th day of January 1988.
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