ML20203N008
| ML20203N008 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 09/17/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20203N004 | List: |
| References | |
| NUDOCS 8609230029 | |
| Download: ML20203N008 (3) | |
Text
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UNITED STATES
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION DIESEL FIRE PUMP FUEL LINE RUPTURE PROTECTION BRUNSWICK STEAM ELECTRIC PLANT UNITS 1 & 2 CAROLINA POWER & LIGHT C0.
DOCKET NOS. 50-324/325
1.0 BACKGROUND
By letter dated June 23, 1977, Carolina Power & Light (CP&L), the licensee for Brunswick Units 1 & 2 (BSEP 1 & 2), connitted to install an excess flow switch and automatic shutoff valve in the fuel supply line for the diesel fire pump.
The purpose of this modification was for the protection of the electric fire pump in the case of a rupture of the fuel supply line.
In this event a flow switch was to detect rupture flow and initiate closure of the shutoff valve and thus stop flow.
By letter dated September 19, 1985, CP&L advised that technical difficulties prevented the use of a flow switch to initiate closure of a shutoff valve in the diesel fire pump supply line when a rupture occurred because normal flow was within 97% of rupture flow. A switch capable of detecting such a small flow differential was indicated as not practicable. This would allow the possibility of disruption of the fuel to the diesel engine during normal operation. CP&L requested relief from this commitment and provided supporting information to show that rupture of the fuel line would not adversely affect the fire protection at BSEP 1 & 2.
l 2.0 EVALUATION The staff agrees with CP&L that distinguishing the quantitative rupture flow from normal flow when they are so close could be difficult in practice. The l
licensee did provide an alternative to assure isolation of the diesel fuel l
and its adverse effects upon the electric fire pump as follows:
l
- 1) automatic sprinklers provide fire suppression capability for the area;
- 2) the diesel fire pump is separated from the electric fire pump by a curb and flame impingement barrier;
- 3) the diesel and electric fire pumps are separated from the diesel fuel tank by a three-hour fire barrier;
- 4) the floor around the diesel fire pump drains into a sump, thus limiting the amount of fuel oil which could be directly exposed to l
l 8609230029 860917 j
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2 the pump and driver;
- 5) fire detection instrumentation located in the area annunciates in the Control Room;
- 6) fire extinguishers and hose stations are located in the immediate vicinity; and
- 7) a well-trained fire brigade exists at BSEP1&2.
The above provisions, with the exception of the " curb" in Item 2, were all available in June, 1977. The curb in conjunction with the sump provides the capability for containing the accidental release of diesel fuel.
The licensee also notes that the National Fire Protection Association (NFPA) discourages use of any valves in the fuel supply line with the exception of a valve at the supply tank outlet. By including the " curb" in the total protection as noted above, the staff considers this a practical alternative to that of the automatic isolation of line rupture. The staff recommends acceptance of this protection in place of CP&L's prior commitment for automatic isolation, since the electric fire pump will not be adversely affected in the event of a diesel fire pump fuel supply break.
3.0 CONCLUSION
CP&L has provided an acceptable alternative to their previous commitment for automatic isolation of diesel fuel upon supply line rupture for protection of the electric fire pump. This alternative includes reliance on existing design features, existing manual and automatic fire protection capabilities, and the addition of a curb and sump to trap spilled oil. The staff recommends its acceptance since, in the event of a diesel fire pump fuel supply line rupture, the alternative protection will not adversely affect the electrically driven fire pump.
Principal Contributor:
D. Katze Dated:
September 17, 1986
I L
Mr. E. E. Utley Brunswick Steam Electric Plant l
Carolina Pcwer & Light Company Units 1 and 2 cc:
Mr. P. W. Howe Mr. C. R. Dietz Vice Presiden't Plant General Manager Brunswick Nuclear Project Brunswick Nuclear Project Box 10429 Box 10429 Southport, North Carolina 28461 Southport, North Carolina 28461 Thomas A. Baxter, Esquire Mr. H. A. Cole Shaw, Pittman, Potts & Trowbridge Special Deputy Attorney General 1800 M Street, N. W.
State of North Carolina Washington, D. C.
20036 P.O. Box 629 Raleigh, North Carolina 27602 Mr. D. E. Hollar Associate General Counsel Mr. Robert P. Gruber Carolina Power & Light Company Executive Director Post Office Box 1551 Public Staff - NCUC Raleigh, North Carolina 27602 P.O. Box 29520 Raleigh, North Carolina 9.7626-0520 Mr. Christopher Chappell, Chairman Board of Commissioners Post Office Box 249 Bolivia, North Carolina 28422 Mrs. Chrys Baggett State Clearinghouse Budget and Management 116 West Jones Street Raleigh, North Carolina 27603 i
Resident Inspector U. S. Nuclear Regulatory Comission Star Route 1 l
Post Office Box 208 Southport, North Carolina 28461' Regional Administrator, Region II U. S. Nuclear Regulatory Comission b3 a ta, eor a Dayne H. Brown, Chief Radiation Protection Branch Division of Facility Services N. C. Department of Human Resources 701 Barbour Drive Raleigh, North Carolina 27603-2008 i
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