ML20207D658

Discusses Results of Review of Use of post-fire Shutdown Repairs to Achieve & Maintain Hot Standby,Per Request at 871029-30 Meetings.Results of Review Encl

ML20207D658
Person / Time
Site:	Davis Besse
Issue date:	08/09/1988
From:	Shelton D TOLEDO EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
1558, IEIN-84-09, IEIN-84-9, TAC-61745, NUDOCS 8808150412
Download: ML20207D658 (8)

Text

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TOLEDO

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u. r,wun tom"$2x0 Docket No. 50-346 License No. NPF-3 Serial No. 1558 August 9, 1988 United States Nuclear Regulatory Comrission Document Control Desk Vashington, D. C. 20555 Subj ect: Fire Protection - Post-Fire Shutdown Repairs (TAC No. 61745)

Gentlemen: .

During a meeting on October 29-30 1987 between representatives of Toledo Edison and the NRC, the NRC Staff Reviewer, Mr. Dennis Kubicki, requested additional information regarding fire protection. One request involved the use of post-fire shutdovn repairs (e.g. the replacement of cables, etc.) to achieve and maintain hot standby, which is contrary to current NRC guidance.

In letter dated May 23, 1988 (Serial No. 1497), Toledo Edison committed to ,

review its two post-fire shutdovn procedures and to identify a resolution for any post-fire shutdown repairs required to achieve and maintain hot standby.

The scope of the review included manual operator actions currently specified in the tvo post-fire shutdovn procedures, procedures referenced by the two procedures, and the manual operator actions committed to be incorporated into the two procedures. The review has been -- pleted and the results are presented in Attachment 1.

The results indicate that the current post-fire shutdown procedures do specify post-fire shutdown repairs required to achieve and maintain hot standby.

These repairs can Le classified as follows:

A) Interim measures pending implementation of the corrective actions required to comply with 10CFR50, Appendix R.

B) Precautionary measures that are NOT required to comply with 10CFR50, Appendix R but only to restore or ensure the operability of a second train of safe shutdovr equipment, b

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Docket No. 50-346 License No. NPF-3 Serial No. 1558 Page 2 C) Repairs associated with equipment necessary to achieve and maintain cold shutdown but not required to achieve or maintain hot standby.

D) Repairs associated with equipment necessary to achieve and maintain hot standby which have been previously approved by the NRC specifically for Davis-Besse or another nuclear power plant.

The repairs that are precautionary measutes may continue to be specified br the post-fire shutdown procedures after completion of the Appendix R corrective actions. These precautionary repairs are not associated with the single train of safe shutdown equipment that must be maintained free of fire damage. Precautionary repairs address only the operability of a second train of safe shutdown equipment, which exceeds the minimum requirements of 10CFR50, Appendix R.

Toledo Edison considers the use of precautionary measures to be a positive enhancement to the Davis-Besse fire prottetion program in that a second means to achieve or maintain safe shutdovn is provided that exceeds the minimum regulatory requirements. The use of precautionary measures vould not represent a distraction to the operators. The precautionary measures are prioritized such that the operators are directed to complete those actions associated with the single train of equipment required to be maintained in the event of a fire prior to performing precautionary measures.

The post-fire shutdovn procedures vill continue to specify repairs that 1) are used only to achieve and maintain cold shutdovn or 2) are used to achieve and maintain hot standby but vere previously accepted by the NRC specifically for Davis-Besse or another nuclear power plant. The interim repairs required to schieve and maintain hot standby vill be eliminated frou the tvo post-fire procedures as the corrective actions for 10CFR50, Appendix h 9re implemented.

The use of repairs as interim actions was approved by the NRC in theit Safety Evaluation Report for the Davis-Besse Fire Protection Program Corrective Action Plan transmitted in letter dated Septer/>er 23, 1983 (Log No. 1375).

Table 1 identifies post-fire shutdovn repaits and the corresponding corrective actions, as applicable, that vill eliminate the need for these repairs.

Please contact Mr. R. V. Schrauder, Nuclear Licensing Manager, at (419) 249-2366 if there are any questions.

Very trul yours,

• m MAL / tit cc A. B. Davis, Regional Administrator 1 DB-1 Resident Inspector D. J. Kubicki, NRC/NRR Staff Reviewer A. V. DeAgazio, NRC/NRR Davis-Besse Project Manager h

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Dockst N3. 50-346 Lic2nsa No. NPF-3 Serial No. 1558

, Attachment 1

.Page 1 ATTACHMENT 1 POST-FIRE SHUTD0VN REPAIRS In letter dated May 23, 1988 (Serial No. 1497), Toledo Edison committed to review its two post-fire shutdown procedures and identify a resolution for any post-fire shutdown repairs required to achieve and maintain hot standby. This review was performed using a repair-identification criteria based on NRC guidance provided in letter dated March 2, 1983 (Log No. 1231) and Information Notice 84-09 dated February 13, 1984 (Log No. 1-915). The repair-identification criteria is as follows:

HOT STANDBY A post-fire shutdown repair required to achieve and maintain hot standby is not consistent with current NRC guidance.

An operator action, whether performed inside or outside the control Room, that is necessary to achieve and maintain hot standby would involve a post-fire shutdown repair if the action vould:

1. dismantle equipment, or

2. utilize tools or other devices not part of the system.

Examples of such repairs vould be lif ting vires, using jumpers, replacing or pulling fuses with a fuse puller or other tool, using shorting bars and disconnecting twist-disconnect plugs.

An operator action would not involve a repair if the action'vould not dismantle equipment or utilize tools or other devices not part of the system. Examples of actions that are not repairs vould be manually repositioning valves through the use of handvheels or handjacks on disengaged motor operators; tripping or racking out circuit breakers; operating hand switches; pulling fuse blocks without a tool.

COLD SHUTD0VN A post-fire shutdown repair used to achieve and maintain cold shutdown is consistent with current NRC guidance. For cold shutdown capability repairs, utilizing tools, dismantling or replacing equipment is acceptable. However, these repairs must be:

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1. Completed in the appropriate time constraints of 10CFR50, Appendix R, and l

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2. Of sufficient quality to assure safe operation until the l plant is restored to its pre-fire condition.

Examples of repairs without sufficient quality are clip leads or jumper cables not fastened with terminal lugs. Cold shutdown i

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. Dockst No. 50-346 Licensa No. NPF-3 Serial No. 1558 Attachment 1 Page 2 capability repairs used in the normal shutdovn mode to satisfy Section III.G.l.b of 10CFR50, Appendix R must be completed within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Cold shutdovn capability repairs used in the alternative or dedicated shutdown mode to satisfy Section III.L of 10CFR50, Appendix R must be completed such that cold shutdown can be achieved within 193 hours0.00223 days <br />0.0536 hours <br />3.191138e-4 weeks <br />7.34365e-5 months <br />. (An exemption was granted by the NRC in letter dated August 20, 1984 (Log No. 1586) which extended the allowable time to achieve cold shutdown from 72 to 193 hours0.00223 days <br />0.0536 hours <br />3.191138e-4 weeks <br />7.34365e-5 months <br />.)

Table 1 identifies the post-fire shutdown repairs that are specified by the two current post-fire shutdown procedures or committed to be incorporated into the two procedures. Table 1 also identifies a corrective action to eliminate the need for the repair or identifies a criteria that is used by Toledo Edison to determine the acceptability of the repair.

The corrective actions involve either a plant modification or a study to establish better data on the limiting times for the Component Cooling Vater System Ventilation to be placed into operation in the event of a fire. The need of this study is discussed in Toledo Edison letter dated June 6, 1988 (Serial No. 1535). The plant modifications and study, including any identified corrective action, vill be implemented by the return to power from the sixth refueling outage.

Four criteria vere used to evaluate the acceptability of a post-fire repair.

The first was that the repair is associated with equipment necessary to achieve and maintain cold shutdown and is not required to achieve or maintain hot standby. Such repairs can be completed within the appropriate time limits and would be of sufficient quality to assure safe operation until the plant is restored to its pre-fire condition.

The second criteria is that the repair was previously discussed with the NRC and found acceptable. During a telephone conversation on December 22, 1983 between Jeff Haverly of Toledo Edison and Guy Vissing and Nick Floravante of the NRC, the proposed modification to install reactor coolant system hot and cold leg indications to satisfy 10CFR50, Appendix R vas discussed. The modification utilizes a portable digital readout device. The circuit for each indication would be disconnected via a multi-pin twist disconnect plug and then connected to the digital readout device as described in letter date May 27, 1987 (Serial No. 1361). On December 27, 1983, the NRC indicated that the use of such a portable device that is plugged in or remotely hooked up was acceptable and had been approved at other plants. Toledo Edison has proceeded in good faith with this modification as discussed with the NRC and considers this repair to be acceptable. This matter was also discussed with NRC Staff Reviewer, Mr. Dennis Kubicki, who approved the use of a portable device using a disconnect plug at a meeting held on July 21, 1988.

The third criteria is that the repair is not required to satisfy the minimu.n requirements of 10CFR50, Appendix R. Such repairs are considered

.. . Dockat No. 50-346 License No. NPF-3 Serial No. 1558 Attachment 1 Page 3 precautionary measures and are not associated with the single train of safe shutdown equipment that must be maintained free of fire damage. Precautionary repairs address only the operability of a second train of safe shutdown equipment, which exceeds the minimum requirements of 10CTR50, Appendix R.

Toledo Edison considers the use of precautionary measures to be a positive enhancement to the Davis-Besse fire protection program in that a second means to achieve or maintain safe shutdown is provided that exceeds the minimum regulatory requirements. Tha use of precautionary measures vould not represent a distraction to the operators. The precautionary measures are prioritized such that the operators are directed to complete those actions associated with the single train of equipment required to be maintained in the event of a fire prior to performing precautionary measures associated with a second train of equipment. Therefore, the precautionary measurer may continue to be specified by the safe shutdown procedure after completion of the Appendix R corrective actions.

The fourth criteria is that a similar repair at another nuclear power plant was approved by the NRC to satisfy 10CFR50, Appendix R. Specifically, the NRC approved the use of temporary ventilation as an alternative shutdown capability to remove the ambient heat load produced by an operating High Pressure Injection (HPI) pump. The establishment of the temporary ventilation is considered a repair required for hot shutdown capability by.the NRC, but was approved since the temporary ventilation could be established prior to the time it would be required before the loss of ventilation vould impact the operation of the HPI pump.

Toledo Edison proposes to use temporary ventilation as an alternative shutdown capability due to the assumed loss of ECCS Room Cooler Fans C31-1 and C31-2 in Fire Area A, Room 115. These fans support the operation of HPI pump 1-2 during hot standby and the cooldown to ultimately achieve cold shutdown. ECCS I

Room Cooler Fans C31-1 and C31-2 are conservatively assumed to be lost upon the occurrence of a serious fire in Fire Area AB and implementation of the post-fire shutdown procedure. The HPI pump has been calculated to be operable for greater than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> without the benefit of the ECCS Room Cooler Fans before the ambient room temperature reaches the maximum design operating temperature of the HPI pump. The temporary ventilation consists of a portable gasoline-power generator, portable electric-driven fan and elephant trunk l ducting, and can be established well within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> based on a trial run of the associated post-fire shutdown procedure. A similar repair has been approved by the NRC to satisfy 10CFR50, Appendix R at another nuclear power plant.

l In summary, post-fire shutdown repairs necessary to achieve and maintain hot standby will be eliminated from the two post-fire shutdown procedures, unless previously accepted by the NRC, upon the implementation of the corrective actions required to satisfy 10CFR50, Appendix R. The necessary revisions to the procedures vill be completed prior to the return to power from the sixth refueling outage.

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.. . Dock 3t No. 50-346 LicInsa No. NPF-3 Serial No. 1558 Table 1 Page 1 TABLE 1 POST-FIRE SHUTD0VN REPAIRS AB'1203.02 "SERIOUS STATION FIRE" Repair Fire Area Resolution Temporary Ventilation A Modification-Upgrade Set up portable generator, Fire Barrier fans and elephant trunk ducting AB Previously accepted by the NRC U (vent Modification-Circuit for DHR Room 113) fire wrap B&G Cold Shutdown Temporary Ventilation U (vent Cold Shutdown Set up portable generator, for CCV Room 328) fans and elephant trunk ducting and use tools.to T Under Study open room damper (See Serial 1535)

RCS Temp. Indication- D & DA Precautionary Use of digital volt meter RCS Temp. Indication D & DA Precautionary Disconnect circuit & attach to digital readout device (future procedure revision)

AFV Governor-Unscrev G&U Modification-Circuit fire viring connection vrap R Precautionary Transfer EDG Fuel Oil- BN Cold Shutdown Use tools and portable pump (future procedure revision)

Insert Fuses T Modification-circuit Fire Vrap

Dockst No. 50-346 Licinss No. NPF-3 Serial No. 1558 Table 1

' Page 2 AB 1203.26 "Serious Control Room Fire" Repair Procedure Reference Resolution Insert Fuses Att 3, Step 8 Precautionary Use of Jumpers Section 4.3.10 & Cold Shutdown Att 11 RCS Temp. Indication- Section 4.1.4 Cold Shutdown Use of Pyrometer Shorting Bar Att 2, Step 1.3 Modification-Disconnect Switches Use of Jumpers & Att 7, Steps 2.3.a,b,c & d Precautionary position PORV slide link Use of Jumpers & Att 7 , Steps 3.4.1 thru 3.4.4 Modification-cut wires Disconnect Svitches Cut Vires Att 2, 4.6.b, 7.2.b & 7.3.b Precautionary Att 2, Steps 3.7.b, 6.3.b & 6.4.0 Modification-Disconnect Switches RCS Temp. Indication Att 8, Steps 1 & 2 Hodification-

-Use of digital volt Disconnect plug meters (current and portable procedure) digital readout device I

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- . . LDockot Na.'50-346 Liesnsa No. NPF-3 Serial No. 1558 Table 1 Page 3 AB 1203.26 "Serious Control Room Fire" Repair Procedure Reference Resolution RCS Temp. Indication Future Procedure revision Previously

-Disconnect circuit Accepted by NRC

& attach to digital readout device Use of Shorting Att 13 Modification-Bar & cut vires Disconnect Switches Remove leads and Att 10, Steps 1 thru 4 Precautionary connect digital volt meter 9

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