ML15056A120

NFPA-805 60 Days RAI Response follow-up Fire Modeling Draft RAI (Round 2)

ML15056A120
Person / Time
Site:	Robinson
Issue date:	02/05/2015
From:	Barillas M C Plant Licensing Branch II
To:	Hightower R E Duke Energy Generation Services
References
Download: ML15056A120 (3)

Text

1 NRR-PMDAPEm Resource From: Barillas, Martha Sent: Thursday, February 05, 2015 4:56 PM To: Richard.Hightower@duke-energy.com Cc: Miller, Barry

Subject:

Robinson NFPA-805 60 days RAI response follow-up Fire Modeling draft RAI (round 2)

Attachments:

Robinson 60-day follow up draft RAIs_Fire Modeling.docx Richard, By letter dated September 16, 2013, Duke Energy Progress Inc., the licensee of H. B. Robinson Steam Electric Plant, Unit 2 (HBRSEP), submitted a license amendment request to change its fire protection program to one based on the National Fire Protection Association (NFPA) Standard 805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition, as incorporated into Title 10

of the Code of Federal Regulations (10 CFR), Part 50, Section 50.48(c) (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13267A211). By letter dated November 24, 2014, and letter dated December 22, 2014, you provided responses to staff request for additional information (RAI) (ADAMS Accession Nos. ML14337A098 and ML15005A073).

To complete its review, the NRC staff has the following follow-up draft request for additional information (RAI) attached.

Please see the attached RAI in DRAFT form.

A Sensitive Unclassified Non-Safeguards Information (SUNSI) review was completed by the staff on the draft RAI and the staff concluded the RAI do not contain SUNSI.

If you find any information needs to be withheld from the public, please notify me within 5 days of receipt of this

email. Please confirm if your staff is available to support a clarification call for these on the February 12, 2015 scheduled call. We are currently scheduled to have a call on PRA RAI #3 regarding its RAI status on this date.

If you are not available, please provide the next possible date for a clarification call.

Respectfully, Martha Barillas

Project Manager

Shearon Harris & H. B. Robinson NRR/DORL/Licensing Branch II-2 US Nuclear Regulatory Commission 301-415-2760

Hearing Identifier: NRR_PMDA Email Number: 1896 Mail Envelope Properties (Martha.Barillas@nrc.gov20150205165500)

Subject:

Robinson NFPA-805 60 days RAI response follow-up Fire Modeling draft RAI (round 2) Sent Date: 2/5/2015 4:55:45 PM Received Date: 2/5/2015 4:55:00 PM From: Barillas, Martha Created By: Martha.Barillas@nrc.gov Recipients: "Miller, Barry" <Barry.Miller@nrc.gov> Tracking Status: None "Richard.Hightower@duke-energy.com" <Richard.Hightower@duke-energy.com> Tracking Status: None Post Office: Files Size Date & Time MESSAGE 1799 2/5/2015 4:55:00 PM Robinson 60-day follow up draft RAIs_Fire Modeling.docx 27677 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received:

Fire Modeling (FM) RAI 01.b.01 In a letter dated November 24, 2014 (ADAMS Accession No. ML14337A098), the licensee responded to FM RAI 01.b and explained how the effect of the increased heat release rate (HRR) due to fire propagation in cable trays wa s accounted for in the hot gas layer (HGL) and multi-compartment analysis (MCA) calculations. In its response, the licensee stated "Fire spread in each tray is assumed to be offset by the burnout."

i. Provide technical justification for this assumption as it is not consistent with the flame spread rates for thermoplastic and thermoset cables recommended in Appendix R of NUREG/CR-6850, "EPRI/NRC-RES Fire PRA Met hodology for Nuclear Power Facilities: Summary and Overview" and Chapter 9 of NUREG/CR-7010, "Cable Heat Release, Ignition, and Spread in Tray Installations During Fire (CHRISTIFIRE)."

In addition, the response does not address the potential effect on the zone of influence (ZOI) from the additional HRR of the cable trays.

ii. Explain how the effect of the increased HRR due to fire propagation in the cable trays was accounted for in the ZOI calculations; or provide technical justification for ignoring this effect.

FM RAI 01.c.01 In a letter dated November 24, 2014 (ADAMS Accession No. ML14337A098), the licensee responded to FM RAI 01.c and explained that intervening combustibles within the ignition source ZOI were identified in the walkdowns, and that the HRR contribution from these combustibles were incorporated in the fire modeling analyses. It appears that the ZOI calculations were only performed for 69 kW, 211 kW, 317 kW, and 702 kW fires. This would imply that the licensee may not have accounted for the additional HRR from non-cable intervening combustibles on the ZOI.

i. Confirm that the effect of the increased HRR from non-cable intervening combustibles was indeed accounted for in the ZOI calculations; or provide technical justification for ignoring this effect.

In addition, the licensee did not provide any details on how the HRR of non-cable intervening combustibles was calculated.

ii. Describe the methodology that was used to estimate the HRR from non-cable intervening combustibles in the ZOI, HGL, and MCA calculations.