ML16022A176

NRR E-mail Capture - South Texas Project Draft Request for Information, Thermal-Hydraulic post-audit for GSI-191 Resolution

ML16022A176
Person / Time
Site:	South Texas
Issue date:	12/11/2015
From:	Lisa Regner Plant Licensing Branch IV
To:	Harrison W South Texas
References
MF2400, MF2401
Download: ML16022A176 (2)

Text

NRR-PMDAPEm Resource From: Regner, Lisa Sent: Friday, December 11, 2015 6:59 AM To: Wayne Harrison Cc: Russell, Andrea; Regner, Lisa

Subject:

FW: STP Initial RAIs

Wayne, Below are draft RAI questions from the T-H audit.

Let me know if you have any questions - these should not be a surprise.

Thanks, Lisa Lisa Regner Sr. PM NRR/DORL/LPL4-1 301-415-1906 O8D08

1. During the audit, STP was considering performing the long term core cooling analysis with the core bypass open to allow flow in the axial direction. Does STP intend to make this change and allow flow axially through the bypass or will STP continue with the bypass completely blocked? If STP is crediting the use of the bypass, they should provide analysis to demonstrate that the bypass will not block during the scenarios. If they are not crediting the bypass, they should inform the NRC that they plan to continue with their current model.

2. During the audit, the NRC staff identified a number of sensitivity studies which would be important for the review of the proposed long term core cooling evaluation methodology. STP should perform the following sensitivity studies and submit plots of the relevant figures of merit and important timings for long term core cooling analysis:

a) Appendix K decay heat load with single worst failure and steam generator tube plugging b) Axial power shape c) Small break sensitivity study with appropriate break size resolution 1

Hearing Identifier: NRR_PMDA Email Number: 2616 Mail Envelope Properties (d58db099ee5b4d3ab7014ad950aa1ade)

Subject:

FW: STP Initial RAIs Sent Date: 12/11/2015 6:59:27 AM Received Date: 12/11/2015 6:59:00 AM From: Regner, Lisa Created By: Lisa.Regner@nrc.gov Recipients:

"Russell, Andrea" <Andrea.Russell@nrc.gov>

Tracking Status: None "Regner, Lisa" <Lisa.Regner@nrc.gov>

Tracking Status: None "Wayne Harrison" <awharrison@STPEGS.COM>

Tracking Status: None Post Office: HQPWMSMRS05.nrc.gov Files Size Date & Time MESSAGE 1311 12/11/2015 6:59:00 AM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

NRR-PMDAPEm Resource From: Regner, Lisa Sent: Friday, December 11, 2015 6:59 AM To: Wayne Harrison Cc: Russell, Andrea; Regner, Lisa

Subject:

FW: STP Initial RAIs

Wayne, Below are draft RAI questions from the T-H audit.

Let me know if you have any questions - these should not be a surprise.

Thanks, Lisa Lisa Regner Sr. PM NRR/DORL/LPL4-1 301-415-1906 O8D08

1. During the audit, STP was considering performing the long term core cooling analysis with the core bypass open to allow flow in the axial direction. Does STP intend to make this change and allow flow axially through the bypass or will STP continue with the bypass completely blocked? If STP is crediting the use of the bypass, they should provide analysis to demonstrate that the bypass will not block during the scenarios. If they are not crediting the bypass, they should inform the NRC that they plan to continue with their current model.

2. During the audit, the NRC staff identified a number of sensitivity studies which would be important for the review of the proposed long term core cooling evaluation methodology. STP should perform the following sensitivity studies and submit plots of the relevant figures of merit and important timings for long term core cooling analysis:

a) Appendix K decay heat load with single worst failure and steam generator tube plugging b) Axial power shape c) Small break sensitivity study with appropriate break size resolution 1

Hearing Identifier: NRR_PMDA Email Number: 2616 Mail Envelope Properties (d58db099ee5b4d3ab7014ad950aa1ade)

Subject:

FW: STP Initial RAIs Sent Date: 12/11/2015 6:59:27 AM Received Date: 12/11/2015 6:59:00 AM From: Regner, Lisa Created By: Lisa.Regner@nrc.gov Recipients:

"Russell, Andrea" <Andrea.Russell@nrc.gov>

Tracking Status: None "Regner, Lisa" <Lisa.Regner@nrc.gov>

Tracking Status: None "Wayne Harrison" <awharrison@STPEGS.COM>

Tracking Status: None Post Office: HQPWMSMRS05.nrc.gov Files Size Date & Time MESSAGE 1311 12/11/2015 6:59:00 AM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received: