ML20092K963
| ML20092K963 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 02/21/1992 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9202260091 | |
| Download: ML20092K963 (4) | |
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DALTIMORC OAS AND CLECTRIC 1650 CALVERT CUFFS PARKWAY e LUSDY, MARYLAND 20657 4702 Gr omot C CRt tt.
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February 21,1992 U. S. Nuclear Regulatory Commission Washington, DC 20555 NITENTION:
Document Control Desk SUlUECT:
Calvert Cliffs Nuclear Power Plant Unit No.1; Docket Nos. 50 317 Reauest for Pegiona! Waiver of Qimpliance REl:liRENCE:
(a) 1xtter from Mr. O. C. Creel (llO&E) to Document Control Desk (NRC), " Temporary Non. Code Repair of ASME Code Class 3 Piping," dated November 27,1991 Gentlemen:
Baltimore Oas & Electric Company (BO&E) hereby requests a temporary waiver of cornpliance from Technical Specification 3.7.10. " Watertight Doors", in order to permit a repair to the Saltwater System without a plant shutdown We believe that this is the safest course of action because it would avoid an unaccessary thermal transient associated with a plant shutdown. -Performing the repair during operation does not present any significant safety concerns.
1(EOUIEEMENT FOlt WillCil A WAIVER IS ItEOUESTEll Technical Specification 3,7.10," Watertight Doors", states that the listed watertight doors are to be closed except when the door is being used for normal entry and exit, item b is " Service Water Pump Room to lleater Day Doors (2)." If the specified doors are not closed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the plant is to be in llot Standby within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
There are two watertight doors between the Service Water Pump Room and the Turbine Building: a double equipment door and a single personnel door, in order to drain the saltwater header and perform the repair, it is necessary to run various lines and cables through the equipment door (Door 214), thereby violating the condition that it be closed "except when the door is being used for normal entry and exit."
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u Document Control Desk February 21,1W2 Pag *e 2 Cll(CUMNTANCES SUltitOUNI) LNG Tile NEEI) FOlt A WAIVlill On February 20.1W2 at 12:25 p.m., llO&E declared the Unit 1 No.11 Saltwater header inoperable due to a through wall leak. His placed the plant in a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> action statement leading to plant shutdown (Technical Specification 3.7.5.1). It is necessary to drain a portion of the No.11 header in ordct to perform an ASME Code-compliant repair to the Saltwater header. He system will be drained into the Senice Water Pump floom and sum) pumps will be used to transfer the drained water to the Turbine Building summ Additionally, t is necessary to run various electrical and pneumatic lines and cables through t1e door. Since the repair cannot be performed without having the door open, which requires the requested waiver, prompt action is required.
This circumstance could not have been forescen. In November,1991, BO&E identified a small leak from the No.11 saltwater header and obtained permission to perform a temporary non-Code repair (lleference A). At that time we committed to examine the leak in three months and confirm that our analysis is still valid. Upon examination of the leak, we determined that the leak site had enlarged and no longer fell within out original analysis. A decision was made to perform a Code-compliant repair of the leak. When the original examination and analysis was performed, we believed that the leak site would not substantially degrade prior to its repair in the next refueling outage, scheduled for March,1W2.
COMPENSATOlW ACTIONS We will post a watch at the watertight door at all times that it is open and lines are placed through the door. Should a Dooding event occur in the Senice Water Pump lloom or in the Turbine Building, the watch will disconnect the lines and cables and close the door. A review of cur it. rnal Gooding studies has confirmed that there will be sufficient time to disconnect the lines and cablu and close the door should the worst case Dooding event occur.
sal'h'iY SIGNIFICANCE / POTENTIAL, CONSEOUENCES The consequences of a worst case pipe failure in the Turbine Building with the wr.tertight door open would be the Dooding of the Service Water Pump Room. His would result in all Senice Water Pumps and the motor-driven Auxiliary Feedwater Pump being rendered inoperable.
Previously performed analyses have shown that, should a worst case Dooding event occur, there will be sufficient time (greater than 10 trinutes) for the posted watch to disconnect the lines and cables and close the door.
1)UllATION OF Tile WAIVElt We request that the walver be granted until 12:25 p.m. on February 23,1992-If the repair is not performed and the No.11 saltwater header returned to senice by that time, Technical Specification 3.7.5.1," Saltwater System", requires that the plant be in llot Standby within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, in order to perform the repair, it is necessary to run various lines and cables through the door.
Therefore, we request that the duration of the waiver encompass the maximum repair time (i.e., the 72-hour action statement for the Saltwater System).
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D9eument Control Desk Feb uary21,1992 f
". page 3 I)l?l'El(MINATION Ol' SIGNiflCANT II4ZAltl)S ne proposed waiver has been evaluated against the standards in 10 CFil Past 50.92 and has been determmed to not involve a significant hazards consideration, in that operation of the facility in accordance with the propn ed waiver:
1.
II'ould not irovhe a sigrdjicant increase in the probability or consequences of an accident previously evaluated.
The watertight door is not an initiator to uny lneviously evaluated accident. Therefore, the requested waiver will not increase the probabihty of any accident previously evaluated.
The only previously evaluated accident which requires that the watertight door be closed is a flooding event. Should a worst case Dooding event occur, sufficient time will exist before the watet level reacher the bottom of the door for the posted watch to disconnect the lines and cables r,nd close the doar. Herefore, there is no increase in the consequences of any previously analyzed accident.
2.
It'ould not create the possibility of a new or di))crent type of accident frvin any accident previously evaluated.
This waiver will not result in any physical changes to the plant or any new or significantly different type of operations from those routinely performed. Therefore,it will not create the possibility of a new or different type of accident from any accident previously evaluated.
3.
Il'ould not involve a significant reduction in a rnargin ofsafety, The margin of safeiy provided by the watertight door is to ensure the protection of safety related equipment from the effects of water escaping from ruptured pipes or components in adjoining rooms. Previous analysis has shown that should such a ruptere occur, there is sufficient time to close the watertight door prini to any safety related equipment being affected. Therefore, the requested waiver does not involve a reduction in a margin of safety.
ENViltONMENTAl, CONSEOUENCES The granting of the requested waiver will not result in the release of any radioactive or chemical materials to the environment. Neither will the granting of the requested waiver change the operation of or limitations on radioactive or chemical waste processing systems. Therefore, the granting of the requested waiver has no environmental consequer.:es.
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Document Control Desk February 21,1W2 l' age 4 sal' lily COS1511'l*lEEJlallSY
'ihls proposed waiver of Technical Specification 3.7.10 and our discussion of significant hazards considerations have been reviewed by our Plant Operations and Safety Review Committee. They concur that utilization of this waiver will not result in an undue risk to the health and safety of the public.
Should you have any further questions regarding this matter, we will be pleased to discuss thern with you.
Very truly yours,
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GCC/IlDht/bdm!bjd/dlm cc:
D. A. litune, Esquhe J. E. Silberg, Esquite R. A. Capra, NRC D. G. hicDonald, Jr., NRC T. T. h1attin, NRC P. R. Wilson, NRC R.1. hiclean, DNR J.11. Walter, PSC 4
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