ML17350A000
| ML17350A000 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 12/16/2017 |
| From: | NRC |
| To: | NRC/NRO/DNRL/LB1 |
| References | |
| Download: ML17350A000 (3) | |
Text
1 NuScaleDCRaisPEm Resource From:
Cranston, Gregory Sent:
Saturday, December 16, 2017 7:54 AM To:
RAI@nuscalepower.com Cc:
NuScaleDCRaisPEm Resource; Lee, Samuel; Chowdhury, Prosanta; Dias, Antonio; Li, Chang; Bavol, Bruce
Subject:
Request for Additional Information No. 302 RAI No. 9276 (5.2.5)
Attachments:
Request for Additional Information No. 302 (eRAI No. 9276).pdf Attached please find NRC staffs request for additional information concerning review of the NuScale Design Certification Application.
Please submit your technically correct and complete response within 60 days of the date of this RAI to the NRC Document Control Desk. The NRC Staff recognizes that NuScale has preliminarily identified that the response to this question in this RAI is likely to require greater than 60 days.
If you have any questions, please contact me.
Thank you.
Gregory Cranston, Senior Project Manager Licensing Branch 1 (NuScale)
Division of New Reactor Licensing Office of New Reactors U.S. Nuclear Regulatory Commission 301-415-0546
Hearing Identifier:
NuScale_SMR_DC_RAI_Public Email Number:
329 Mail Envelope Properties (MWHPR09MB12004789EEDBDB972A27ECF190080)
Subject:
Request for Additional Information No. 302 RAI No. 9276 (5.2.5)
Sent Date:
12/16/2017 7:54:27 AM Received Date:
12/16/2017 7:54:34 AM From:
Cranston, Gregory Created By:
Gregory.Cranston@nrc.gov Recipients:
"NuScaleDCRaisPEm Resource" <NuScaleDCRaisPEm.Resource@nrc.gov>
Tracking Status: None "Lee, Samuel" <Samuel.Lee@nrc.gov>
Tracking Status: None "Chowdhury, Prosanta" <Prosanta.Chowdhury@nrc.gov>
Tracking Status: None "Dias, Antonio" <Antonio.Dias@nrc.gov>
Tracking Status: None "Li, Chang" <Chang.Li@nrc.gov>
Tracking Status: None "Bavol, Bruce" <Bruce.Bavol@nrc.gov>
Tracking Status: None "RAI@nuscalepower.com" <RAI@nuscalepower.com>
Tracking Status: None Post Office:
MWHPR09MB1200.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 713 12/16/2017 7:54:34 AM Request for Additional Information No. 302 (eRAI No. 9276).pdf 95418 Options Priority:
Standard Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
Recipients Received:
Request for Additional Information No. 302 (eRAI No. 9276)
Issue Date: 12/16/2017 Application
Title:
NuScale Standard Design Certification 048 Operating Company: NuScale Power, LLC Docket No.52-048 Review Section: 05.02.05 - Reactor Coolant Pressure Boundary Leakage Detection Application Section: 5.2.5 QUESTIONS 05.02.05-6 10 CFR 50, Appendix A, General Design Criterion (GDC) 30 requires, in part, that means be provided for detecting and, to the extent practical, identifying the location of the source of reactor coolant leakage. Regulatory Guide 1.45, Guidance on Monitoring and Response to Reactor Coolant System Leakage, describes acceptable methods for implementing GDC 30 with respect to the selection of reactor core pressure boundary (RCPB) leakage detection systems.
In TS LCO 3.4.7, RCS Leakage Detection Instrumentation, NuScale uses three reactor coolant system (RCS) detection methods: (a) containment evacuation system (CES) condensate, (b) CES pressure, and (c) CES radiation monitor. The detection capability of methods (a) and (b) satisfies the quantitative guidance of detecting 1 gpm leakage within one hour, as indicated in RG 1.45. However, method (c) does not satisfy the above quantitative guidance, but provides qualitative capability for the RCS leakage detection as indicated in FSAR Section 5.2.5.
As a follow-up to the teleconference with NuScale on October 18, 2017 relating to the clarification on NuScales response to eRAI 8863 Question 06.02.04-4, the staff reviewed the statement in the RAI response that with two of the methods inoperable due to high containment pressure, reactor operators will perform the required actions within specified completion times according to the technical specifications. The referenced TS LCO 3.4.7 has in the required actions for Condition A, One required leakage detection channel inoperable, to perform SR 3.4.5.1, once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This required action does not meet NRC guidance in RG 1.45, Regulatory Positions C.2.2 and C.2.3. Position C.2.3 states that plant technical specifications should identify at least two independent and diverse methods that have the detection capabilities specified in C.2.2, which is detecting the leakage of up to 1 gpm within one hour. The staff finds that performing SR 3.4.5.1 may not meet the criterion of detecting 1 gpm leakage within one hour. If the two required methods used to satisfy the LCO requirement are either (a) and (c), or (b) and (c), and if in Condition A (One required leakage detection channel inoperable) and the only remaining available method under this condition is method (c), the CES gaseous radioactivity monitor, which does not have the capability specified in C.2.2 of RG 1.45, then the performance of SR 3.4.5.1 is inadequate. Therefore, Position C.2.3 of RG 1.45 is not satisfied.
Therefore, LCO 3.4.7, which could rely on the two methods (a) and (c), or methods (b) and (c), would not meet Position C.2.3 if either method (a) or (b) were inoperable. Since LCO 3.4.7 specifies two of the three methods, (a), (b), and (c) shall be operable, and method (c), gaseous radioactivity monitor, does not meet the capability guidance of C.2.2, the TS does not meet RG 1.45 and is inadequate.
The applicant is requested to revise the proposed LCO 3.4.7 to be consistent with RG 1.45 Positions C.2.2 and C.2.3 as discussed above.