ML23322A002
| ML23322A002 | |
| Person / Time | |
|---|---|
| Site: | 99902078 |
| Issue date: | 11/18/2023 |
| From: | NRC |
| To: | NRC/NRR/DNRL/NRLB |
| References | |
| Download: ML23322A002 (4) | |
Text
From:
Getachew Tesfaye Sent:
Saturday, November 18, 2023 9:11 AM To:
Request for Additional Information Cc:
Thomas Hayden; Mahmoud Jardaneh; Griffith, Thomas; Osborn, Jim; NuScale-SDA-720RAIsPEm Resource
Subject:
NuScale SDAA Section 9.1.5 - Request for Additional Information No. 010 (RAI-10105-R1)
Attachments:
SECTION 9.1.5 - RAI-10105-R1-FINAL.pdf Attached please find NRC staffs request for additional information (RAI) concerning the review of NuScale Standard Design Approval Application for its US460 standard plant design (Agencywide Documents Access and Management System (ADAMS) Accession No. ML222339A066).
Please submit your technically correct and complete response by the agreed upon date to the NRC Document Control Desk.
If you have any questions, please do not hesitate to contact me.
Thank you, Getachew Tesfaye (He/Him)
Senior Project Manager NRC/NRR/DNRL/NRLB 301-415-8013
Hearing Identifier:
NuScale_SDA720_RAI_Public Email Number:
18 Mail Envelope Properties (BY5PR09MB56828B8E2814227594B86F2C8CB6A)
Subject:
NuScale SDAA Section 9.1.5 - Request for Additional Information No. 010 (RAI-10105-R1)
Sent Date:
11/18/2023 9:10:47 AM Received Date:
11/18/2023 9:10:52 AM From:
Getachew Tesfaye Created By:
Getachew.Tesfaye@nrc.gov Recipients:
"Thomas Hayden" <Thomas.Hayden@nrc.gov>
Tracking Status: None "Mahmoud Jardaneh" <Mahmoud.Jardaneh@nrc.gov>
Tracking Status: None "Griffith, Thomas" <tgriffith@nuscalepower.com>
Tracking Status: None "Osborn, Jim" <josborn@nuscalepower.com>
Tracking Status: None "NuScale-SDA-720RAIsPEm Resource"
<NuScale-SDA-720RAIsPEm.Resource@usnrc.onmicrosoft.com>
Tracking Status: None "Request for Additional Information" <RAI@nuscalepower.com>
Tracking Status: None Post Office:
BY5PR09MB5682.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 585 11/18/2023 9:10:52 AM SECTION 9.1.5 - RAI-10105-R1-FINAL.pdf 149592 Options Priority:
Normal Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
1 REQUEST FOR ADDITIONAL INFORMATION No. 010 (RAI-10105-R1)
BY THE OFFICE OF NUCLEAR REACTOR REGULATION NUSCALE STANDARD DESIGN APPROVAL APPLICATION DOCKET NO. 05200050 CHAPTER 9, AUXILIARY SYSTEMS SECTION 9.1.5, OVERHEAD HEAVY LOAD HANDLING SYSTEMS ISSUE DATE: 11/18/2023
=
Background===
By letter dated December 15, 2022, NuScale Power, LLC (NuScale or the applicant),
submitted Part 2, Final Safety Analysis Report, (FSAR), Chapter 9, Auxiliary Systems, Revision 0, (Agencywide Documents Access and Management System Accession No. ML22364A281) of the NuScale Standard Design Approval Application (SDAA) for its US460 standard plant design. The applicant submitted US460 plant SDAA in accordance with requirements of Title 10 Code of Federal Regulations (10 CFR) Part 52, Licenses, Certifications, and Approvals for Nuclear Power Plants, Subpart E, Standard Design Approvals. The NRC staff has reviewed the information on the New and Spent Fuel Storage provided in Chapter 9 of the FSAR and determined that additional information is required to complete its review.
Question 9.1.5-3 REGULATORY BASIS GDC 1, 2 and 4 of Appendix A to 10 CFR Part 50 apply to the design, fabrication, and testing of SSCs important to safety to maintain quality standards, to the ability of structures, equipment, and mechanisms to withstand the effects of earthquakes, and to the protection of safety-related equipment from the effects of internally generated missiles (i.e., dropped loads), respectively.
ISSUES SDAA FSAR Table 9.1.5-1, "Heavy Load Handling Equipment Design Data," Note 1 for the reactor building crane main hoist and lower block assembly lists the following two items:
Item 4332: Use of 1.11 for the design factor in plate buckling for extreme environmental loads. The basis is not clear justifying the use of the 1.11 design factor for plate buckling under extreme environmental loads.
Item 4334: Alternate methodology for spacing of transverse stiffeners. No alternate methodology was described for determining the spacing of transverse stiffeners.
INFORMATION REQUESTED For Item 4332, provide and justify the basis for the design factor of 1.11 for plate buckling under extreme environmental loads. The basis for this design factor can borrow from the justification used in the ASME Code change, but for clarity should be submitted for review.
For Item 4334, describe the alternate methodology for the spacing of transverse stiffeners.
If required, update Section 9.1.5 accordingly.
2 Question 9.1.5-6 REGULATORY BASIS GDC 1, 2 and 4 of Appendix A to 10 CFR Part 50 apply to the design, fabrication, and testing of SSCs important to safety to maintain quality standards, to the ability of structures, equipment, and mechanisms to withstand the effects of earthquakes, and to the protection of safety-related equipment from the effects of internally generated missiles (i.e., dropped loads), respectively.
ISSUE In SDAA FSAR Section 9.1.5.3, Safety Evaluation, the applicant indicates that the heavy load exclusion zones represent areas where heavy loads cannot travel without additional measures because a heavy load drop in the exclusion zones could potentially impact safe shutdown equipment, cause a release of radioactive materials, or a criticality accident that could cause unacceptable radiation exposures.
In SDAA FSAR Section 9.1.5.2.3, "System Operation," on page 9.1-44, the third paragraph states: "Heavy load exclusion zones and safe load paths" Figure 9.1.5-1, "Reactor Building Crane Safe Load Path," provides the safe load path only when moving the Nuclear Power Modules in the RXB. But figure(s) and clear discussions of "the heavy load exclusion zones and safe load paths," for each overhead heavy load handling system were not provided in Section 9.1.5 of the SDAA.
One example of a heavy load exclusion zone is the spent fuel pool (SFP). A dropped load on the SFP could potentially produce a radiation release, this is prevented by design and by the heavy load exclusion zones. The staff noted that the SFP is covered and protected by the refueling floor, but the NuScale design includes cranes capable of handling loads that could exceed the refueling floor design.
COL Item 9.1-5 instructs applicants that reference the NuScale Power Plant US460 standard design to provide a description of the program governing heavy loads handling (which includes a detailed description of the safe load paths for movement of heavy loads). However, the staff finds that this COL Item does not provide the future applicant with a reference to acceptable methods of developing the heavy loads handling program. The staff notes that providing a properly crafted COL Item could be an acceptable path to address the staff's concerns related to the heavy load exclusion zones and safe load paths identified in this RAI.
INFORMATION REQUESTED The staff requests the applicant to update the FSAR Section 9.1.5, COL Item 9.1-5 or to add a new COL Item that provides guidance for future applicants to define the heavy load exclusion zones and safe load paths for each overhead heavy load handling system and refer to the applicable provision(s) of industrial code(s).