ML23117A027
| ML23117A027 | |
| Person / Time | |
|---|---|
| Site: | 99902069, Hermes File:Kairos Power icon.png |
| Issue date: | 04/28/2023 |
| From: | Rempe J Advisory Committee on Reactor Safeguards |
| To: | David Petti Advisory Committee on Reactor Safeguards |
| References | |
| Download: ML23117A027 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, DC 20555 - 0001 April 28, 2023 MEMORANDUM TO:
David Petti, Lead Kairos Power Licensing Subcommittee Advisory Committee on Reactor Safeguards FROM:
Joy Rempe, Chairman Advisory Committee on Reactor Safeguards
SUBJECT:
INPUT FOR ACRS REVIEW OF KAIROS NON-POWER REACTOR HERMES CONSTRUCTION PERMIT APPLICATION - DRAFT SAFETY EVALUATION FOR CHAPTER 10, EXPERIMENTAL FACILITIES AND UTILIZATION In response to the Subcommittees request, I reviewed the NRC staffs draft safety evaluation (SE) with no open items, and the associated section of Kairos Power LLCs (Kairos or the applicants) Hermes Preliminary Safety Analysis Report (PSAR), for Chapter 10, Experimental Facilities and Utilization. The following is my recommended course of action concerning further review of this chapter and the staffs SE.
Background
In Chapter 10 of the PSAR, the applicant notes the Hermes non-power production and utilization facility (NPUF), which is constructed to test and demonstrate the key technologies, design features, and safety functions of fluoride salt-cooled, high temperature reactor technologies and associated structures, systems, and components (SSCs), does not include special facilities dedicated to the conduct of reactor experiments or experimental programs.
The applicant acknowledges the Hermes design allows performance of startup physics testing and maneuvering operations at various power levels to assess plant performance and capabilities. The applicant references other PSAR sections where information may be found related to such activities (e.g., Section 12.11 for startup testing; Section 9.3 for monitoring the pebble handling and storage system; and Section 4.3 for the vessel material surveillance system).
Staff considered guidance in NUREG-1537 in their review. The guidance emphasizes that Chapter 10 should describe and discuss the intended use of the experimental facilities and the planned experimental program. Safety analysis for each type of experimental facility should be provided. The guidance notes NPUFs may be used for many purposes, including radiation physics, chemistry, and biology studies, materials irradiation, radionuclide production and education purposes. At many NPUFs, the experiment facilities are integral components of the reactor. Some NPUFs are operated as critical facilities to demonstrate fuel loading and perform
reactor physics studies. In such cases, the reactor itself can be considered an experimental facility. In this case, the safety analysis and experiment technical specifications (TSs) should include the limitations on core configurations and operational limitations.
SE Summary In the draft SE, the staff finds Hermes does not include any facilities penetrating or located near the reactor that are specifically designed as experimental facilities. Hence, staff concludes a separate evaluation, using the guidelines of NUREG-1537, is not required. The draft SE emphasizes Hermes does include unusual and novel SSCs and features to monitor their performance. These SSCs and features, as well as the quality program and TSs to help ensure their quality, performance, and safe operation, are evaluated in other SE chapters.
Discussion Although the staff Chapter 10 review was appropriate, members raised several questions related to possible operating activities in which the reactor is an experiment. I recommend ACRS request staff provide additional information that clarifies their plans to ensure such activities are identified and that appropriate controls will be in place for safely completing them. Possible activities include:
Validation of reactivity, temperature, and power coefficients Fuel performance and degradation monitoring during operation Monitoring of materials corrosion and degradation Justification of thermodynamic data and associated vapor pressure correlations of representative species Monitoring of sensor performance Validation of core design and analysis methods Confirmatory testing of plant systems, structures, and components during plant operation These concerns are not items expected to be resolved prior to issuance of the Operating License. These items are identified by the staff and listed in Appendix A of the staff SE.
However, additional details are needed to understand how the applicant will address uncertainties associated with a first-of-a-kind technology demonstration facility that cannot be resolved until after the facility is operational. These concerns must be addressed by appropriate safety analyses and TSs.
Recommendation As lead reviewer for Hermes SE Chapter 10, I concur with the staff that information in Chapter 10 of the PSAR is adequate for this Construction Permit application. No additional actions from the staff or applicant are needed to complete our review of this chapter. Our discussions regarding Chapter 10 SE information, however, led to several items that I recommend members explore in subsequent chapter reviews of this application.
References
- 1.
USNRC, Draft Safety Evaluation for Hermes NonPower Reactor Preliminary Safety Analysis Report Chapter 10, January 2023 (ML23017A120)
- 2.
USNRC, Appendix A to the safety evaluation for the Hermes construction permit application, Post Construction Permit Activities - Construction Permit Conditions and Additional Items for the Operating License Application, March 2, 2023 (ML23065A058)
- 3.
Kairos Power LLC, Submittal of the Preliminary Safety Analysis Report for the Kairos Power Fluoride Salt-Cooled, High Temperature Non-Power Reactor (Hermes), Revision 2, February 2023 (ML23055A672)
- 4.
USNRC, NUREG-1537, Part 1, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors, Format and Content, issued February 1996 (ML042430055)
- 5.
USNRC, NUREG-1537, Part 2, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors, Standard Review Plan and Acceptance Criteria, issued February 1996 (ML042430048)
- 6.
USNRC, NUREG-1537, Final Interim Staff Guidance Augmenting NUREG-1537, Part 1, Guidelines for Preparing and Reviewing Applications for Licensing Non-Power Reactors:
Format and Content for Licensing Radioisotope Production Facilities and Aqueous Homogeneous Reactors, October 17, 2012 (ML12156A069)
April 27, 2023
SUBJECT:
INPUT FOR ACRS REVIEW OF KAIROS NON-POWER REACTOR HERMES CONSTRUCTION PERMIT APPLICATION - DRAFT SAFETY EVALUATION FOR CHAPTER 10, EXPERIMENTAL FACILITIES AND UTILIZATION Package No: ML23117A000 Memo Accession No: ML23117A027 Publicly Available Y Sensitive N Viewing Rights:
NRC Users or ACRS Only or See Restricted distribution *via e-mail OFFICE ACRS/TSB*
SUNSI Review*
ACRS/TSB*
ACRS*
NAME WWang WWang LBurkhart (WWang for) JRempe DATE 4/27/2023 4/27/2023 4/27/2023 4/27/2023 OFFICIAL RECORD COPY