ML23017A154
| ML23017A154 | |
| Person / Time | |
|---|---|
| Site: | Hermes |
| Issue date: | 01/10/2023 |
| From: | Benjamin Beasley NRC/NRR/DANU/UAL1 |
| To: | Advisory Committee on Reactor Safeguards |
| Shared Package | |
| ML23017A120 | List: |
| References | |
| Download: ML23017A154 (1) | |
Text
10 EXPERIMENTAL FACILITIES AND UTILIZATION THIS NRC STAFF DRAFT SE HAS BEEN PREPARED AND IS BEING RELEASED TO SUPPORT INTERACTIONS WITH THE ACRS. THIS DRAFT SE HAS NOT BEEN SUBJECT TO FULL NRC MANAGEMENT AND LEGAL REVIEWS AND APPROVALS, AND ITS CONTENTS SHOULD NOT BE INTERPRETED AS OFFICIAL AGENCY POSITIONS.
Non-power reactors may have many experimental uses. Many non-power reactors have special experimental facilities, which may penetrate the core or reflector, be located near the core, or be an integral part of the reactor. Using these facilities, samples can be irradiated in the core, or reflector, or neutron or other radiation beams can be extracted from the core region through the biological shield. In addition to these traditional experimental purposes, some non-power reactors may be operated primarily to gather information and data that could be useful for the purposes of licensing future prototype facilities and power reactors. Such non-power reactors may not include specific experimental facilities, but the reactor itself and/or specific structures, systems, and components (SSCs) could be considered experimental facilities to demonstrate technology for eventual prototype and commercial scale up.
Kairos Power LLCs (Kairos) Hermes preliminary safety analysis report (PSAR), Revision XX, Chapter 10, Experimental Facilities and Utilization, Section 10.1, Summary Description, states that Hermes will not include special facilities dedicated to the conduct of reactor experiments or experimental programs. However, as discussed in PSAR Chapter 1, The Facility, Section 1.1, Introduction, Kairos purpose for Hermes is to test and demonstrate the key technologies, design features, and safety functions of Kairos fluoride salt-cooled, high temperature reactor (KP-FHR) technology and its associated SSCs. As part of its construction permit review, the U.S. Nuclear Regulatory Commission (NRC) staff (the staff) evaluated descriptions and discussions of Hermes SSCs in the PSAR, paying special attention to design and operating characteristics, unusual or novel SSCs being demonstrated by Hermes, and principal safety considerations. The preliminary design of unusual or novel SSCs, including special safety features for these SSCs and any added instrumentation or other features to monitor the performance of these SSCs, was evaluated to ensure the sufficiency of principal design criteria; design bases; information relative to materials of construction, general arrangement, and approximate dimensions; and high-level functional descriptions, to provide reasonable assurance that the final design will conform to the design bases. The information provided by Kairos in the PSAR was also evaluated to determine whether it was adequate to provide reasonable assurance that a Title 10, Code of Federal Regulations (10 CFR) Part 50 construction permit for the Hermes facility could be issued in accordance with applicable regulatory requirements and guidance on the basis that the facility could be constructed without undue risk to the health and safety of the public. The staff evaluations of unusual or novel Hermes SSCs are found in other chapters of this safety evaluation report (SER), particularly Chapter 3, Design of Structures, Systems, and Components, Chapter 4, Reactor Description, Chapter 5, Heat Transport System, Chapter 6, Engineered Safety Features, and Chapter 9, Auxiliary Systems.
In addition, the staff reviewed Kairos Quality Assurance Program Description (QAPD) for ensuring the quality and performance of Hermes SSCs during the design, construction, and operation of the facility. The staff documented its review of Kaiross QAPD in Chapter 12, Conduct of Operations, Section 12.9, Quality Assurance, of this SER.
The staff also reviewed Kairos identification and justification for the selection of those variables,
conditions, or other items which are determined to be probable subjects of technical specifications (TSs) for the facility, with special attention given to those items which may significantly influence the final design. The staff documented its review of Kairos probable subjects of TSs for the facility in Chapter 14, Technical Specifications, of this SER.
PSAR Sections 4.3.1.1.1, 4.3.3, and 10.1 describe a material surveillance system (MSS), which is supported by the reactor vessel top head and provides a means to insert and remove material specimens (e.g., coupons) to support testing and assessment of material performance. During the General Audit, Kairos confirmed that, consistent with PSAR Section 10.1, the MSS is not an experimental facility because the purpose of the MSS is to monitor and evaluate the performance of SSCs over Hermes operating life and Kairos does not plan to use the MSS to evaluate or irradiate other novels or experimental materials, i.e., which are not representative of Hermes SSCs. Kairos also confirmed that any use of the MSS would not affect analyses of Hermes operation or accidents in PSAR Chapters 4 and 13.
The staff evaluated the descriptions and discussions of the Hermes facility in the PSAR and found that the preliminary design of the facility does not include any facilities penetrating or located near the reactor that are specifically designated as experimental facilities. The staff notes that the Hermes facility includes unusual and novel SSCs that are an integral part of the facility, including tri-structural isotropic particle (TRISO) fuel, Flibe salt coolant, with others, and that the facility includes features to monitor the performance of these SSCs test to demonstrate the key technologies, design features, and safety functions of Kairos KP-FHR technology.
However, these SSCs and features, as well as the QAPD and probable subjects of TSs that will help ensure the quality, performance, and safe operation of SSCs, are evaluated in other chapters of this SER, as discussed above. Therefore, the staff concludes that a separate evaluation using the guidelines of NUREG-1537, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors, Part 2, Standard Review Plan and Acceptance Criteria, Chapter 10, Experimental Facilities and Utilization, is not required.
The staff will confirm that the final design conforms to the design basis, including that Hermes will not include special facilities dedicated to the conduct of reactor experiments or experimental programs, during its review of a Hermes operating license application.
References Kairos Power LLC. Hermes Non-Power Reactor Preliminary Safety Analysis Report, Revision
- 0. September 2021. ADAMS ML21272A375.
Letter from U.S. Nuclear Regulatory Commission, Report on General Regulatory Audit for the Hermes Construction Permit Application Review, dated XX, 2022. ADAMS Accession No. MLXXXXXXXXX.
The U.S. Nuclear Regulatory Commission (NRC). NUREG-1537, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors, Part 1, Format and Content, and Part 2, Standard Review Plan and Acceptance Criteria. NRC: Washington, D.C. February 1996. ADAMS Accession Nos. ML042430055 and ML042430048.