ML16036A193

NRR E-mail Capture - South Texas Project Units 1 & 2, Draft Request for Additional Information, Updated Epnb Questions for GSI-191

ML16036A193
Person / Time
Site:	South Texas
Issue date:	02/05/2016
From:	Lisa Regner Plant Licensing Branch IV
To:	Harrison W South Texas
References
MF2400, MF2401
Download: ML16036A193 (3)

Text

NRR-PMDAPEm Resource From: Regner, Lisa Sent: Friday, February 05, 2016 11:09 AM To: Wayne Harrison Cc: Michael Murray; Sterling, Lance (lsterling@STPEGS.COM)

Subject:

Modified EPNB draft Question - GSI-191

Wayne, Below is the modified EPNB question that I will use to replace in the EPNB questions in the draft RAI Round 3, Section A sent on Jan. 14 (ADAMS Accession No. ML16022A008).

Under the Component Performance section of the draft RAI, EPNB RAIs 1, 2, and 3 will be replaced with:

EPNB RAI 1. In Attachment 1-2, page 4, of the August 20, 2015 submittal, the licensee stated that the large main steam and feedwater line breaks were not evaluated because recirculation is not required under the plant licensing basis for STP. (1) Explain why sump recirculation is not required for main steam and feedwater line breaks inside the containment. (2) Discuss whether any other ASME Code Class 2 piping inside the containment, besides the main steam and feedwater lines, are evaluated for debris generation and sump recirculation. If none, explain why ASME Code Class 2 piping inside the containment are not evaluated.

EPNB RAI 2. In Attachment 1-4, page 22, of the August 20, 2015 submittal, under the heading, Reactor Coolant System Weld Mitigation, the licensee stated that All STP large bore RCS welds susceptible to pressurized water stress corrosion cracking (PWSCC) have been replaced with Alloy 690 material which is not susceptible to PWSCC (SG nozzles) or overlaid with non-susceptible Alloy 52/52M/152 material (pressurizer piping safe ends) with the exception of the reactor vessel nozzle welds

a. Clarify whether the reactor vessel nozzle welds discussed in the above statement are the J-groove welds associated with the reactor vessel closure head penetration nozzles to house the control rod drive mechanisms (i.e., CRDM nozzles), or the full-penetration butt welds associated with the hot leg nozzles that are attached to the reactor vessel shell.

b. Discuss whether the CRDM nozzles in both units are made of Alloy 600 material and the associated J-groove welds are made of Alloy 82/182 welds. If yes, discuss why break locations were not selected at the CRDM nozzles because Alloy 600/82/182 material is susceptible to PWSCC. If no, discuss the material.

c. (1) Identify the large bore RCS piping (e.g., hot leg, cold leg or crossover piping) and other ASME Code Class 1 pipes (e.g., pressurizer surge line, pressurizer spray line, or safety injection piping) that contain either Alloy 690 weld material or are mitigated with Alloy 52/52M/152 material and that are considered in GSI-191 evaluation. (2) Identify all ASME Class 1 piping that is larger than 2-inch that still contain Alloy 82/182 weld material, has not been mitigated with Alloy 52/52M/152 material and are considered in GSI-191 evaluation.

EPNB RAI 3. Explain why breaks from pressurizer heater sleeves and reactor vessel bottom mounted instrumentation nozzles were not considered as a source of debris generation.

Please let me know if you have further questions or need clarification.

Thank you, Lisa 1

Lisa Regner Sr. PM NRR/DORL/LPL4-1 301-415-1906 O8D08 2

Hearing Identifier: NRR_PMDA Email Number: 2643 Mail Envelope Properties (1f3715f9f4184361a93f4a48f283d16c)

Subject:

Modified EPNB draft Question - GSI-191 Sent Date: 2/5/2016 11:08:39 AM Received Date: 2/5/2016 11:08:40 AM From: Regner, Lisa Created By: Lisa.Regner@nrc.gov Recipients:

"Michael Murray" <mpmurray@STpegs.com>

Tracking Status: None "Sterling, Lance (lsterling@STPEGS.COM)" <lsterling@STPEGS.COM>

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

Tracking Status: None Post Office: HQPWMSMRS01.nrc.gov Files Size Date & Time MESSAGE 2992 2/5/2016 11:08:40 AM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

NRR-PMDAPEm Resource From: Regner, Lisa Sent: Friday, February 05, 2016 11:09 AM To: Wayne Harrison Cc: Michael Murray; Sterling, Lance (lsterling@STPEGS.COM)

Subject:

Modified EPNB draft Question - GSI-191

Wayne, Below is the modified EPNB question that I will use to replace in the EPNB questions in the draft RAI Round 3, Section A sent on Jan. 14 (ADAMS Accession No. ML16022A008).

Under the Component Performance section of the draft RAI, EPNB RAIs 1, 2, and 3 will be replaced with:

EPNB RAI 1. In Attachment 1-2, page 4, of the August 20, 2015 submittal, the licensee stated that the large main steam and feedwater line breaks were not evaluated because recirculation is not required under the plant licensing basis for STP. (1) Explain why sump recirculation is not required for main steam and feedwater line breaks inside the containment. (2) Discuss whether any other ASME Code Class 2 piping inside the containment, besides the main steam and feedwater lines, are evaluated for debris generation and sump recirculation. If none, explain why ASME Code Class 2 piping inside the containment are not evaluated.

EPNB RAI 2. In Attachment 1-4, page 22, of the August 20, 2015 submittal, under the heading, Reactor Coolant System Weld Mitigation, the licensee stated that All STP large bore RCS welds susceptible to pressurized water stress corrosion cracking (PWSCC) have been replaced with Alloy 690 material which is not susceptible to PWSCC (SG nozzles) or overlaid with non-susceptible Alloy 52/52M/152 material (pressurizer piping safe ends) with the exception of the reactor vessel nozzle welds

a. Clarify whether the reactor vessel nozzle welds discussed in the above statement are the J-groove welds associated with the reactor vessel closure head penetration nozzles to house the control rod drive mechanisms (i.e., CRDM nozzles), or the full-penetration butt welds associated with the hot leg nozzles that are attached to the reactor vessel shell.

b. Discuss whether the CRDM nozzles in both units are made of Alloy 600 material and the associated J-groove welds are made of Alloy 82/182 welds. If yes, discuss why break locations were not selected at the CRDM nozzles because Alloy 600/82/182 material is susceptible to PWSCC. If no, discuss the material.

c. (1) Identify the large bore RCS piping (e.g., hot leg, cold leg or crossover piping) and other ASME Code Class 1 pipes (e.g., pressurizer surge line, pressurizer spray line, or safety injection piping) that contain either Alloy 690 weld material or are mitigated with Alloy 52/52M/152 material and that are considered in GSI-191 evaluation. (2) Identify all ASME Class 1 piping that is larger than 2-inch that still contain Alloy 82/182 weld material, has not been mitigated with Alloy 52/52M/152 material and are considered in GSI-191 evaluation.

EPNB RAI 3. Explain why breaks from pressurizer heater sleeves and reactor vessel bottom mounted instrumentation nozzles were not considered as a source of debris generation.

Please let me know if you have further questions or need clarification.

Thank you, Lisa 1

Lisa Regner Sr. PM NRR/DORL/LPL4-1 301-415-1906 O8D08 2

Hearing Identifier: NRR_PMDA Email Number: 2643 Mail Envelope Properties (1f3715f9f4184361a93f4a48f283d16c)

Subject:

Modified EPNB draft Question - GSI-191 Sent Date: 2/5/2016 11:08:39 AM Received Date: 2/5/2016 11:08:40 AM From: Regner, Lisa Created By: Lisa.Regner@nrc.gov Recipients:

"Michael Murray" <mpmurray@STpegs.com>

Tracking Status: None "Sterling, Lance (lsterling@STPEGS.COM)" <lsterling@STPEGS.COM>

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

Tracking Status: None Post Office: HQPWMSMRS01.nrc.gov Files Size Date & Time MESSAGE 2992 2/5/2016 11:08:40 AM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received: