ML23040A141
| ML23040A141 | |
| Person / Time | |
|---|---|
| Site: | 99902071 |
| Issue date: | 06/22/2023 |
| From: | Michael Orenak NRC/NRR/DANU/UAL1 |
| To: | Proffitt J NRC/NRR/DANU/UAL1 |
| Shared Package | |
| ML23040A145 | List: |
| References | |
| EPID L?2022?TOP?0051 | |
| Download: ML23040A141 (5) | |
Text
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION MEMORANDUM TO:
Joseph A. Proffitt, Acting Branch Chief Advanced Reactor Licensing Branch 1 Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation FROM:
Michael D. Orenak, Project Manager Advanced Reactor Licensing Branch 1 Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF THE DECEMBER 14, 2022, CLOSED MEETING BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION STAFF AND X ENERGY, LLC REGARDING THE GRAPHITE QUALIFICATION METHODOLOGY TOPICAL REPORT Meeting Information:
Applicant: X Energy LLC Docket/Project No. 99902071 EPID: L2022TOP0051 Public Meeting Notice Agencywide Documents Access and Management System (ADAMS):
Accession No.: ML22327A049 U.S. Nuclear Regulatory Commission (NRC) Staff Discussion Points ADAMS Accession No.:
ML23039A188 Meeting Attendees: See Enclosure for list of meeting attendees.
CONTACT: Michael D. Orenak, NRR/DANU (301) 415-3229 June 22, 2023 Signed by Orenak, Michael on 06/22/23
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Meeting Summary:
The U.S. Nuclear Regulatory Commission (NRC) staff held a virtual closed public meeting with representatives from XEnergy, LLC (Xenergy). The meeting was conducted in accordance with NRC Management Directive 3.5, Attendance at NRC Staff-Sponsored Meetings (ML21180A271). The main points of discussion during the meeting included:
The topical report (TR) needs to identify how Xenergy is meeting the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code,Section III, Division V, High-Temperature Reactors. Any deviations from the ASME BPV Code will need to be justified by Xenergy.
Regarding bullet #1 of the NRC staff feedback, Xenergy intends to use grade-specific testing for the graphite to be used within the reactor. Xenergy plans to conduct oxidation testing at low temperatures because it results in greater strength loss per mass loss.
Regarding bullet #2 of the NRC staff feedback, Xenergy views the graphite as having a defense-in-depth radionuclide retention function, along with having a required safety function of maintaining geometry (principal design criteria (PDC) 2 and 70) and heat removal (PDC 34).
The NRC staff clarified that the TR should include how the list of PDCs were determined and a description of how the reflector meets those PDCs.
Regarding bullet #3 of the NRC staff feedback, Xenergy stated that testing at Oak Ridge National Lab and existing data will cover the full temperature range that the reactor graphite may see. All graphite properties will be covered by tests and existing data besides creep.
Xenergy suggested that creep and the creep model could be covered in a future submittal.
The NRC staff was unsure about this approach and stated that they will need to get back to Xenergy with their thoughts after Xenergy determines if creep will not be included in the TR.
The NRC staff then asked of Xenergy is intending on gathering creep data for the full temperature range. Xenergy replied that they still need to figure out what their approach will be.
Regarding bullet #4 of the NRC staff feedback, Xenergy stated that there is no need to evaluate for the Wigner effect because temperatures will not be below ((
)) in the reactor. The NRC staff stated that the staffs concern is about the graphite experiencing very high fluences at temperatures under ((
)). Xenergy stated that the design depends on high fluence values and that they will be performing stored energy tests at
((
)).
Regarding bullet #5 of the NRC staff feedback, Xenergy stated that they will be using ((
))
graphite for the inside reflector and control rod sleeves, and the ((
)) would be facing the highest fluence values. X-energy will be using either ((
)) or ((
)) for the remaining portions of the reflector. The NRC staff stated that Xenergy needs to clarify the location and interface of the grades of graphite. Xenergy then stated that the two grades of graphite would be in physical contact in the reactor and that that interface would be clarified in a revision to the TR.
Regarding bullet #6 of the NRC staff feedback, Xenergy stated they will discuss the creep model in a future submittal. Xenergy believe their graphite would operate beyond the turnaround fluence but is not expected to operate beyond the crossover fluence.
OFFICIAL USE ONLY - PROPRIETARY INFORMATION J. Proffitt The discussion then went to the graphite testing section of the NRC staff discussion points document. Regarding bullet #1 of the graphite testing, Xenergy stated that there is only a graphite-ongraphite interaction, so no differing materials are in contact in the design and abrasion should be less of a concern.
Regarding bullet #2 of the graphite testing, Xenergy stated that they understand it is their responsibility to develop the needed data.
Regarding bullet #3 of the graphite testing, Xenergy stated that they are planning to use historical data and extrapolation for the full temperature range. The NRC staff stated that Xenergy needs to make it more clear what data they have, what data they need, and when they will obtain the needed data.
Regarding bullet #4 of the graphite testing, Xenergy stated that the data will have the full temperature range.
Regarding bullet #5 of the graphite testing, the NRC stated that Xenergy will need to clarify at what temperatures for which grades they will and wont have creep data. In addition, Xenergy needs to clarify when the creep data will be obtained and when the creep model will be completed.
The NRC staff provided a few comments at the end of the discussion. First, the NRC staff made it known that due to the significant information deficiencies, the detailed review was stopped; therefore, more questions or technical concerns may arise in reviewing the revised TR.
Additionally, the ASME BPV Code has requirements for the use of historical data. If the historical data to be used by Xenergy doesnt meet the ASME BPV Code requirements, X-energy should have a discussion of the delta and a justification for the applicability of the data. Finally, the NRC staff stated that the TR should demonstrate how any data used for graphite qualification meets ASME Code requirements for unirradiated/irradiated/oxidized property data.
Xenergy stated in the meeting that is likely that they will withdraw the TR and resubmit, however; their exact path forward has yet to be determined. On December 20, 2022, Xenergy told the NRC staff that they will be withdrawing the report and resubmitting.
Enclosure:
List of Meeting Attendees OFFICIAL USE ONLY - PROPRIETARY INFORMATION
Pkg: ML23040A145 Letter: ML23040A143 : ML23039A188 PDF: ML23040A141 NRR052 OFFICE NRR/DANU/UAL1/PM NRR/DANU/UAL1/LA NRR/DANU/UAL1/BC(A)
NRR/DANU/UAL1/PM NAME MOrenak DGreene JProffitt MOrenak DATE 2/9/2023 5/17/2023 6/22/2023 6/22/2023
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION Enclosure List of Meeting Attendees Public Meeting With XEnergy Llc Regarding Xe100 Reactor Training Programs Methodology Topical Report Thursday, October 20, 2022 Name Organization Lucieann Vechioli Feliciano U.S. Nuclear Regulatory Commission (NRC)
Mike Orenak NRC Matt Gordon NRC Julie Ezell NRC Kate Dowling NRC Margret Audrain NRC William Jessup NRC Ian Jung NRC Alex Chereskin NRC Ryann Bass NRC Michelle Hayes NRC Ingrid Nordby XEnergy LLC (Xenergy)
Travis Chapman Xenergy Jon Facemire Xenergy Steve Vaughn Xenergy Maggie Staiger Xenergy Charlotte Geiger Xenergy James Roll Xenergy Tim Lucas Xenergy Paul Loza Xenergy Sam Baylis Xenergy Mark Natale US Department of Energy Anthony Schoedel Contractor for Xenergy Gwennal Beirnaert Contractor for Xenergy Don Behnke Contractor for Xenergy