ML23291A051
| ML23291A051 | |
| Person / Time | |
|---|---|
| Site: | 99902078 |
| Issue date: | 10/18/2023 |
| From: | NRC |
| To: | NRC/NRR/DNRL/NRLB |
| References | |
| Download: ML23291A051 (6) | |
Text
From:
Getachew Tesfaye Sent:
Wednesday, October 18, 2023 7:52 AM To:
Request for Additional Information Cc:
Taylor Lamb (She/Her); Mahmoud Jardaneh; Griffith, Thomas; Osborn, Jim; NuScale-SDA-720RAIsPEm Resource
Subject:
NuScale SDAA Section 9.2 - Request for Additional Information No. 005 (RAI-10089-R1)
Attachments:
SECTION 9.2 - RAI-10089-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:
13 Mail Envelope Properties (BY5PR09MB568249B9AC9F3788A36093CF8CD5A)
Subject:
NuScale SDAA Section 9.2 - Request for Additional Information No. 005 (RAI-10089-R1)
Sent Date:
10/18/2023 7:52:17 AM Received Date:
10/18/2023 7:52:20 AM From:
Getachew Tesfaye Created By:
Getachew.Tesfaye@nrc.gov Recipients:
"Taylor Lamb (She/Her)" <Taylor.Lamb@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 10/18/2023 7:52:20 AM SECTION 9.2 - RAI-10089-R1-FINAL.pdf 159545 Options Priority:
Normal Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
1 REQUEST FOR ADDITIONAL INFORMATION No. 005 (RAI-10089-R1)
BY THE OFFICE OF NUCLEAR REACTOR REGULATION NUSCALE STANDARD DESIGN APPROVAL APPLICATION DOCKET NO. 05200050 CHAPTER 9, AUXILIARY SYSTEMS SECTION 9.2, WATER SYSTEMS ISSUE DATE: 10/18/2023
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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 the US460 plant SDAA in accordance with the 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 in Chapter 9 of the FSAR and determined that additional information is required to complete its review.
Question 9.2.2-1 REGULATORY REQUIREMENT Content of Application; Technical Information, 10 CFR 52.137(a)(2) states, in part, with regards to the systems, structures, and components (SSCs), that the description shall be sufficient to permit understanding of the system design and their relationship to the safety evaluation.
ISSUE The staff reviewed the information provided in the FSAR in Part 2, Section 9.2.2, Reactor Component Cooling Water System, (RCCWS) and determined that it does not fully satisfy the regulatory requirement because it does not contain sufficient information necessary to obtain an understanding of the functional system design and operation, nor does it contain any schematic or drawings that show the functional arrangement. Specifically, Section 9.2.2 does not contain sufficient information on the system design, configuration, and operation to allow the staff to conclude that system failure will not adversely affect plant safety or radiological release from the plant during normal operation.
Additionally, the FSAR has included no information on the system operating parameters (i.e.,
flows, temperatures, and pressures) during normal operation, or the ability to isolate the system if there is a failure in part of the system, either specific to one module or common to all modules.
The relevant requirements of the Commissions regulations for this area of review, and the associated acceptance criteria, are given in Standard Review Plan (SRP) Section 9.2.2, Revision 4, Reactor Auxiliary Cooling Water System, issued March 2007. The requirements include the following:
General Design Criterion (GDC) 2, Design bases for protection against natural phenomena, as it relates to the capability of structures housing the system and the system
2 itself to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without a loss of safety-related functions.
GDC 4, Environmental and dynamic effects design bases, as it relates to the capability of the system and the structure housing the system to withstand the effects of missiles inside and outside of containment, the effects of pipe whip and jets, environmental conditions from high-and moderate-energy line breaks, and the dynamic effects of flow instabilities and loads (e.g., water hammer) during normal plant operation and upset or accident conditions.
GDC 60, Control of Releases of Radioactive Materials to the Environment, as it relates to the turbine gland sealing system design for the control of releases of radioactive materials to the environment.
GDC 64, Monitoring Radioactivity Releases, as it relates to the turbine gland sealing system design for monitoring releases of radioactive materials to the environment during normal operation, including anticipated operational occurrences.
10 CFR 20.1406, Minimization of Contamination, as it relates to the design features that will facilitate eventual decommissioning and minimize, to the extent practicable, the contamination of the facility and the environment and the generation of radioactive waste.
Also, GDC 26 requires Reactivity control system redundancy and capability. Specifically, two independent reactivity control systems of different design principles shall be provided. One of the systems shall use control rods, preferably including a positive means for inserting the rods, and shall be capable of reliably controlling reactivity changes to assure that, under conditions of normal operation, including anticipated operational occurrences (AOOs), and with appropriate margin for malfunctions such as stuck rods, specified acceptable fuel design limits are not exceeded. Therefore, although the non-safety related RCCWS is not required for safe shutdown, its operation is necessary to assure that the control rod drive system meets the requirements of GDC 26 for reliably controlling reactivity changes under conditions of normal operation, including AOOs.
For the staff to perform the review of the RCCWS, it is necessary that the system location, general configuration, and performance and design parameters be included in the design description. In order for the staff to understand the system design and its relationship to plant safety, FSAR Section 9.2.2 must provide a description of the system configuration including applicable schematic diagrams that identify system boundaries and interfaces, along with design and performance data, that identifies the normal operating parameters for the system including flow, pressure, temperature, etc. The ability to isolate the system or portions of the system in the event that intersystem leakage is detected or if there is a break in a RCCWS pipe inside the reactor containment or the reactor building should also be discussed in the FSAR.
FSAR Section 9.2.2 does not contain sufficient information on the system design, configuration, and operation to allow the staff to conclude that system failure will not adversely affect plant safety or radiological release from the plant during normal operation.
REQUESTED INFORMATION The staff requests that NuScale provide and include in Section 9.2 of the FSAR the following information:
3
- 1. A RCCWS schematic that will allow the staff to review and determine, in accordance with GDCs 2 and 4, that failure of RCCWS SSCs in the reactor building or which pass through containment will not damage other SSCs important safety due to pipe whip, flooding, or other effects. A similar schematic was included in FSAR Section 9.2.2 of the design certification FSAR.
- 2. Design information on safety and seismic design categorization, in accordance with GDC 2, for the SSCs that penetrate the containment and are in close proximity to the reactor (RCCWS supply and return to and from the control rod drive mechanisms (CRDMs)).
- 3. Information on the RCCWS heat removal capacity and demand requirements, such as for the CRDMs, during normal operation (note that GDC 26 requires control rod drives to be operable during AOOs).
- 4. In accordance with 10 CFR 20.1406, information on how the system provides adequate radiation monitoring to indicate in-leakage to the system from a contaminated system that it interfaces with, how the system is designed so that leakage from the system can be detected, and how appropriate system isolation can be initiated.
- 5. System design information on leakage detection from the system and how it provides for isolation to comply with the requirements of GDC 60 and 64 as they relate to control of releases of radioactive materials to the environment and monitoring radioactivity releases.
Question 9.2.3-1 REGULATORY REQUIREMENT Content of Application, Technical Information, 10 CFR 52.137(a)(2) states, in part, with regards to the systems, structures, and components (SSCs), that the description shall be sufficient to permit understanding of the system design and their relationship to the safety evaluation.
ISSUE The staff reviewed the information provided in SDAA Part 2, Section 9.2.3 and determined that it does not fully satisfy this requirement because it does not contain sufficient information regarding the demineralized water system (DWS) necessary to obtain an understanding of the system design and operation. Specifically, Section 9.2.3 does not contain sufficient information on the system design, configuration, and operation to allow the staff to conclude that system failure will not adversely affect plant safety or radiological release from the plant during normal operation.
SDAA, Section 9.2.3.2 does not provide a description of the DWS system that would allow the staff to review the design against applicable NRC regulations. It does not contain system design information or what plant SSCs it supplies with demineralized water. In SDAA Section 9.2.3.3, Safety Evaluation, it states that: (1) consistent with GDC 2, the design and layout of the DWS includes provisions that ensure that a failure of the system does not adversely affect the functional performance of safety-related systems or components; (2) consistent with GDC 2, portions of the system in proximity to Seismic Category I SSCs are designed to the Seismic Category II standard; and (3) Section 12.3, Radiation Protection Design Features, provides
4 information on the design features of the DWS that demonstrate compliance with 10 CFR 20.1406.
Since the FSAR contains no DWS system design information, does not give the location of SSCs in the DWS system, and does not specify what SSCs it services, the staff is unable to make a finding on the system ability to comply with GDC 2 or 10 CFR 20.1406.
REQUESTED INFORMATION The staff requests that NuScale provide and include in SDAA Section 9.2.3 the DWS design information, including a design description that identifies the systems that are serviced, a system flow diagram that shows the system functional arrangement and major components. Similar information that is being requested here was included in the corresponding sections of the design certification FSAR.