ML15189A236

BFN SL: Revised Follow-up RAI

ML15189A236
Person / Time
Site:	Browns Ferry
Issue date:	07/01/2015
From:	Saba F E Plant Licensing Branch II
To:	Williams G R Tennessee Valley Authority
References
Download: ML15189A236 (4)

Text

1 NRR-PMDAPEm Resource From: Saba, Farideh Sent: Wednesday, July 01, 2015 3:17 PM To: 'Williams, Gordon Robert' Cc: Razzaque, Muhammad; Schrull, Edwa rd Dustin (edschrull@tva.gov)

Subject:

BFN SL: Revised Follow-up RAI Attachments:

Browns Ferry Dome Pressure TS Follow-up RAI.docx Importance:

High Gordon, By letter to the Nuclear Regulatory Commission (NRC) dated December 11, 2014, Tennessee Valley Authority (TVA), licensee of the Browns Ferry Nuclear Plant (BFN) Units 1, 2, and 3 submitted a License Amendment Request (LAR) for review and approval of a revision to the BFN Technical Specification (TS) Section 2.1.1 to reflect a lower reactor steam dome pressure for Reactor Core Safety Limits 2.1.1.1 and 2.1.1.2. TVA states that the revision is needed to address the potential to exceed the low pressure TS safety limit. After reviewing the responses to the request for additional inform ation (CNL-15-085, June 3, 2015) the NRC staff has determined that follow-up additional information is needed.

The NRC staff revised follow up RAI is attached. Per our telephone conversation today, you confirmed that you agree with the NRC staff determination that the follow up RA I does not contain any sensitive information. Also, you agreed to respond to the RAI by July 31, 2015.

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

Hearing Identifier: NRR_PMDA Email Number: 2194 Mail Envelope Properties (032edc96fc374c1eba015ded0cb00504)

Subject:

BFN SL: Revised Follow-up RAI Sent Date: 7/1/2015 3:17:27 PM Received Date: 7/1/2015 3:17:27 PM From: Saba, Farideh Created By: Farideh.Saba@nrc.gov Recipients: "Razzaque, Muhammad" <Muhammad.Razzaque@nrc.gov>

Tracking Status: None "Schrull, Edward Dustin (edschrull@tva.gov)" <edschrull@tva.gov> Tracking Status: None "'Williams, Gordon Robert'" <grwilliams1@tva.gov> Tracking Status: None

Post Office: HQPWMSMRS05.nrc.gov Files Size Date & Time MESSAGE 1177 7/1/2015 3:17:27 PM Browns Ferry Dome Pressure TS Follow-up RAI.docx 22461

Options Priority: High Return Notification: No Reply Requested: Yes Sensitivity: Normal Expiration Date: Recipients Received:

REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST FOR TECHNICAL SPECIFICATION CHANGES TO RECTOR CORE SAFETY LIMITS TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNITS 1,2, AND 3 DOCKET NO. 50-259, 50-260, AND 50-296 Byletter to the Nuclear Regulatory Commission (NRC) datedDecember 11, 2014,Tennessee Valley Authority (TVA),licenseeof the Browns Ferry Nuclear Plant (BFN)Units 1, 2, and 3 submittedaLicenseAmendmentRequest (LAR) for review and approval of a revisiontotheBFNTechnicalSpecification(TS) Section 2.1.1 to reflect a lower reactor steam dome pressure for Reactor Core Safety Limits 2.1.1.1 and 2.1.1.2. TVAstatesthat therevisionis needed to address the potential to exceed the low pressure TS safety limit. After reviewing the responses to the request for additional information (CNL-15-085, June 3, 2015) theNRC staff hasdetermined that follow-up additional information is needed. RAI-08: Response to RAI-04b points out for pressures below 700 psia an enthalpy offset is added to the nodal enthalpy used by the SPCB/GE14 correlation. The dashed curves in Figure 4.5 appear to be horizontal extensions from the corresponding values at 700 psia.

a) Clarify with an example how the offset was applied in generating the dashed curves in Figure 4.5 of ANP-3245P Revision 1 (Attachment 5 to the LAR).

b) Did the limiting case with the minimum steam dome pressure shown in Figure 3.2 of ANP-3245P Revision 1 reach a core inlet condition that is saturated (two-phase)? What is the core inlet enthalpy when the steam dome pressure reaches the minimum in Figure 3.2? Will the SPCB/GE14 correlation issue an error message during the transient calculation when the core inlet or the node of interest reaches a condition that is beyond the applicability range of the correlation?

c) The SPCB correlation is applicable to the ATRIUM -10 fuel. The SPCB/GE14 correlation was developed using the indirect method (Indirect Correlation Application) and is applicable to the legacy GE14 fuel in BFN Unit1 for pressures not less than 700 psia. Clarify whether the solid curves in Figure 4.5 were calculated using the SPCB or the SPCB/GE14 correlation.

d) The last paragraph on page 4-2 of the AREVA topical report ANP-3245P Revision 1 states, "For pressures that are lower than the SPCB/GE14 700 psia correlation boundary, the critical power will be evaluated as though the pressure was at 700 psia (preserving the same inlet subcooling). The results of applying the SPCB/GE14 correlation to pressures lower than 700 psia is illustrated with dashed lines in Figure 4.5 and indicates that the alternative low pressure boundary treatment is conservative". It appears that the term "conservative" is used because the dashed line values are lower than the solid line values when the pressure is lower than 700 psia. However, the SPCB correlation is not applicable to the GE14 fuel and the SPCB/GE14 correlation is not applicable for pressures lower than 700 psia. Justify how the alternative low pressure boundary treatment is conservative.