ML20210C761
| ML20210C761 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 09/12/1986 |
| From: | Cutter A CAROLINA POWER & LIGHT CO. |
| To: | Muller D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20210C766 | List: |
| References | |
| NLS-86-311, NUDOCS 8609180422 | |
| Download: ML20210C761 (3) | |
Text
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Cp&L Carotma Power & Light Company SERIAL: NLS-86-311 86TSB12 SEP 12 1986 Director of Nuclear Reactor Regulation Attention:
Mr. Dan Muller, Director BWR Project Directorate #2 Division of BWR Licensing United States Nuclear Regulatory Commission Washington, DC 20355 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. I AND 2 DOCKET NOS.30-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 REQUEST FOR LICENSE AMENDMENT RCIC STEAM LINE ISOLATION TIME
Dear Sir:
SUMMARY
In accordance with Code of Federal Regulations, Title 10, Parts 30.90 and 2.101, Carcima Power & Light Company (CP&L) hereby requests a revision to the Technical Specifications (TS) for the Brunswick Steam Electric Plant, Unit Nos. I and 2. The proposed revisicn to Section 3/4.6.3 extends the allowable isolation tiine for the RCIC steam line isciation valves from 20 seconds to 30 seconds. Amendment No.126 for Brunswick-2, issued on June !O,1986, granted a similar change on a temporary basis.
DISCUSSION Technical Specification 3/4.6.3 requires the RCIC steam line isolation valves to close within 20 seconds. The isolation time for these valves has historically been between 18 and 20 seconds. Therefore, the Company is requesting the a!!owable isolation time be extended to 30 seconds.
An analysis has been performed to determine the effect of extending the isolation time for the RCIC isolation valves on the environmental qualification of safety-related electrical equipment. The worst case line break for the temperature, pressure, and radiation profiles used to establish post-accident environments is the 10-inch HPCI steam line. This line is required to isolate within 30 seconds by T5 Section 3/4.6.3. Areas where an RCIC line break could occur are analyzed for and bounded by the HPCI line break environmental profiles. The total coolant loss as a result cf flow through a ruptured 10-inch HPCI kne for 50 secends would be much greater than that from a ruptured 3-inch RCIC line for 30 seconds. As such, the requested change has no af fect on the environmental qualification program.
The radiological af fects of the extended RCIC isolation time have also been evaluated.
Design basis accident dose estimates at the site boundary are based on a main steam line break. Given the reduced loss of coolant through the 3-inch RCIC line, doses at the site boundary due to a ruptured RCIC line would clearly be well within limits established in 10 CFR 100.
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Consideration has also been givEn to the elfects this change wou!d have el the consequences of a break in the wate" side of the RCIC system. Care!iro Power 4t I.igiit a
Company has determir.ed that the proposed change has no effect on this event becayse the RCIC containment isolation valves are not de. signed to isolate on.a water IMc break.
I There is no concern with regard to increased piping forces resulting from tne proposerl revision. Increasing the isolaticn time of the valves from 20 to 90 seconds will have no adverse effect on piping fon.es because maximwn flow through tlw line is reached within i
seconds of a s!eam line rupture. In addition, these vaives clase slow;y, gradually throttling back the steam f!ow. Therefore, forces anajogous to those associated witn a water hammer event cannot occur.
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SIGNIFICANTJfAZARDS ANALYSIS j
Tne Commission has provided standards for determining whether o significant hazards cer, sideration exists in 10 CFR 5032(c). A proposed amendment to an operating license l
for a facility involves no significant hazards consideration if operation of the facility in i
accordance with th proposed amet.dment wouid not: (1) invoive a significant increase in
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the probability Ge consequences of any accident 1,reviously evaluated;(2) create tl:e possibility of a new or different kind of accident froin any accident previously evaluated; or O) involve a significant reduction in a margin of safety. Carolina Power & Light Company has reviewed this request and determined that:
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The proposed amendment does not involve a significant increase in the probability er consequences 6f any accident previously evaluated. An analysis 4
has been performed which determined that exter. ding the allowable RCIC stum line isolation time to 30 seconds has no effect on the profiles used to establish environmental qualification at Brunswick. These profiles were established based on a rupture of a 10-inch HPCI line with a 50-second I
l isolation time. The amount of coolant lost in 30 seconds through a break in th-3-inch RCIC steam line would be much less than that assumed fer the 10, inch t
HPCI tine bre tk. Therefore, although increasing the isolation time for the 3-inch RCIC steam line results in a slight increase in the consequences of that
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accident, a rupture of the 10-inch HPCI steam line remains the limiting event for environmental qualification purposes. In addttion, it has been determined i
that the radiological effects of this change are bounded by those estimated for main steam line break. While the proposed change could resuit in a slight i
l increase in the amount of radioactivity released upon a RCIC steam line rupture, such a release would be much less than that estimated for a main
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i steam line break and well within 10 CFR 100 limits.
2.
Tne proposed amendment does not create the possibihty of a new or different kind of accident than previously evaluated because the change does not affect the method in which the RCIC system, or any other safety system, performs its safety function. Valve operability will continue to be ensured through periodic stroke time testing to the 30-second limits. As mentioned in item 1, l
j the environmental and cadiological affects of extending the RCIC steam line isolation time have inen shown to be bounded by other scenarics, i
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Director of Nucl2ar Reactor Rcgulation NLS-86-311/ Paga 3
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Tbe pecpoed amendment does not involve a signjticant reduction in a margin of safety because the : light increase in the consequences of a RCIC steam line rupture which could result due to the prcposed change are bounded by those of a main steam tire or 10-inch liPCI line rupture. As such, the extended RCIC steam line isolation time does not present either a radio!ogical or an i
environmental qualification concern. Periodic stroke time testing of the valves will maintain assurance of valve operability.
Based on the above reasoning, CP&I. has determined that the proposed amendment does not icyc!ve a sigoificant haz'ards consMeration.
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/.DMINUiTRATtVE INFORMATION Tl:e revi:eo Brunswick.I and 2 TS pages are govided in Enciosures 1 and 2. The Company has evaluated this reque.st in accorda*.ce with the provisions of 10 CFR 170.12 and riotermined that a' license amendment application fee is required. A check for $150 is enclosed in paytnent of this fee.
Please refer questions regarding this submittal to Mr. Sherwood R. Zimmerman at (9J9) 836-62t 2.
Yours very truly)
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. B. Cutter - Vice j
Nuclear Engineering & Licensing l
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F.nclosures T
cc:
Mr. W. H. Rutand (NRC-SNP)
Dr. J. Nelson Grace (NRC-RII)
Mr. E. Sylvester (NRC)
A, B. Cutter, having beers first duly 3 worn, did depose and say that the information contained herein it. true and correct to the best of his information, knowledge and belief; and the sources of his information are officers, employees, contractors, and agents of Carolkia Power & Light Company.
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