ML15152A306

NRR E-mail Capture - FW: Browns Ferry RAI

ML15152A306
Person / Time
Site:	Browns Ferry
Issue date:	05/29/2015
From:	Farideh Saba Plant Licensing Branch II
To:	Szabo C Tennessee Valley Authority
References
Download: ML15152A306 (2)

Text

NRR-PMDAPEm Resource From: Saba, Farideh Sent: Friday, May 29, 2015 6:53 PM To: Szabo, Clinton William (cwszabo@tva.gov); Williams, Gordon Robert (grwilliams1@tva.gov)

Cc: Schrull, Edward Dustin (edschrull@tva.gov); Hilsmeier, Todd; Robinson, Jay

Subject:

FW: Browns Ferry RAI Importance: High Gordon and Clint, Please see the following follow up RAI for Browns Ferry NFPA 805 LAR. My understanding is that we have discussed this RAI during a conference call on May 7, 2015. The NRC staff is requesting that you provide your response on the docket, for the staff to be able to refer to it in its safety evaluation. Please respond by June 15 to this RAI. Please let me know if you will not be able to support this date.

Thanks, Farideh Farideh E. Saba, P.E.

Senior Project Manager NRC/ADRO/NRR/DORL 301-415-1447 Mail Stop O-8G9A Farideh.Saba@NRC.GOV PRA RAI 18.01 PRA RAI 18 requested clarification about how the compliant and variant plants were modeled to determine the CDF and LERF for the control room and cable spreading room abandonment scenarios. The response to PRA RAI 18 generally states that abandonment scenarios are modeled using the backup control panel for both the post-transition and the complaint plant PRA models, and discusses some functional success paths.

However, the response neither indicates how VFDRs are identified nor how the associated fire-damaged cables and equipment, and thus VFDRs, are removed from the compliant plant quantification in each fire area that includes shutdown from the backup control panel.

a) Confirm that the equipment damaged by each fire in fire areas that includes shutdown from the backup control panel has been identified using the Browns Ferry fire damage methodology and is assumed to fail in the FPRA. If not, please clarify how equipment damage is identified and modeled.

b) Confirm that all applicable equipment undamaged by each fire is nominally available to mitigate the fire, i.e., is credited in the PRA model. Summarize any differences between the nominally available equipment in the complaint versus the variant plant.

c) Explain how the VFDRs within these areas were identified (e.g., must a VFDR fail all success paths in the area and also fail the success path at the backup control panel to be identified as a VFDR?).

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Hearing Identifier: NRR_PMDA Email Number: 2122 Mail Envelope Properties (36CF286628C20846A68047F2463233090145334ED536)

Subject:

FW: Browns Ferry RAI Sent Date: 5/29/2015 6:52:54 PM Received Date: 5/29/2015 6:52:00 PM From: Saba, Farideh Created By: Farideh.Saba@nrc.gov Recipients:

"Schrull, Edward Dustin (edschrull@tva.gov)" <edschrull@tva.gov>

Tracking Status: None "Hilsmeier, Todd" <Todd.Hilsmeier@nrc.gov>

Tracking Status: None "Robinson, Jay" <Jay.Robinson@nrc.gov>

Tracking Status: None "Szabo, Clinton William (cwszabo@tva.gov)" <cwszabo@tva.gov>

Tracking Status: None "Williams, Gordon Robert (grwilliams1@tva.gov)" <grwilliams1@tva.gov>

Tracking Status: None Post Office: HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 2379 5/29/2015 6:52:00 PM Options Priority: High Return Notification: No Reply Requested: Yes Sensitivity: Normal Expiration Date:

Recipients Received: ZZZ