ML25269A127
| ML25269A127 | |
| Person / Time | |
|---|---|
| Site: | 05000614, 99902117 |
| Issue date: | 09/26/2025 |
| From: | Long Mott Energy |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML25269A125 | List: |
| References | |
| 2025-PLM-NRC-010, DE-NE0009040 | |
| Download: ML25269A127 (1) | |
Text
6.4-21 Revision 0 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009040 Copyright © 2025 Long Mott Energy, LLC All Rights Reserved Long Mott Generating Station Preliminary Safety Analysis Report No operator actions, controls, displays, logic circuits, or interlocks are required to ensure that the fuel accomplishes the RSFs. No electric power or interface requirements are required to ensure that the Fuel accomplishes the RSFs. The RCSS, described in Section 6.4.10, provides safe shutdown capability.
6.4.2.3 Fuel Qualification, Testing, and Programs The Xe-100 UCO fuel qualification is basedbuilds upon United States and international operating experience with TRISO fuel particles. The equilibrium core performance envelope of the Xe-100 fuel is based on the Department of Energy's (DOE) Advanced Gas Reactor (AGR) program.
An Xe-100 Phenomenon Identification and Ranking TablesTable (PIRT) werewas performed for fuel pebble behavior. The results are and used to inform the fuel qualification programmethodology, which is described in Reference 6.4.2-1. The main elements of the pre-startup The Xe-100 fuel qualification, are: methodology consists of the following elements:
Establishment of fuel product, equipment, and feedstock specifications.
Implementation of a fuel fabrication processprocesses capable of consistently and reliably meeting the specifications at the required scale.
Implementation of statistical Quality Control/Quality Assurance procedures to demonstrate that the product specifications have been met.
X-energy Pebble Reactor Test (XPeRT) fuel irradiation campaign:
Fabrication of statistically sufficient quantities of UCO fuel kernels, TRISO coating layers, and test fuel pebble elements representative of Xe-100 reactor fuel at the TRISO-X Pilot Facility.
Irradiation of statistically sufficient quantities of fuel pebbles with in-pile monitoring of in-pile performance and post-irradiation examination via lead-out instrumentation to demonstrate that normal operationfuel performance requirements are met under the Xe-100 normal operation fuel performance envelope and that AGR program fuel performance data is applicable to TRISO-coated UCO particles in fuel pebbles.
Post-irradiation examination, of statistically sufficient quantities of irradiated fuel to demonstrate that accident condition performance requirements are metPost-irradiation heating and oxidation tests of irradiated fuel pebbles to demonstrate that fuel performance requirements are met during licensing basis event conditions.
Post-irradiation material examinations of irradiated fuel pebbles to characterize end state attributes, of statistically sufficient quantities of irradiated fuel to demonstrate degradation mechanisms of irradiated fuel are consistent with those found in the fuel of the DOE AGR program and that performance requirements are met during licensing basis events with further confidence.
6.4-22 Revision 0 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009040 Copyright © 2025 Long Mott Energy, LLC All Rights Reserved Full details of the fuel qualification is accomplished through the methodologies discussed in Reference 6.4.2-1 which is incorporated by reference in its entirety. X-energy Pebble Loading Results Examination (XPLoRE) thermal-mechanical properties test campaign:
Unirradiated graphite matrix thermal material properties tests: heat transfer coefficient, specific heat capacity, coefficient of thermal expansion.
Unirradiated graphite matrix mechanical material properties tests: crush strength, impact resistance, restitution coefficient.
Unirradiated graphite matrix tribology tests: static friction coefficient and wear rate between fuel, graphite core structure, and fuel handling system materials.
Evaluation models to conservatively predict fission product release from fuel pebbles under operating, design, and licensing basis event conditions.
Key milestones for the fuel qualification demonstration testing campaigns are presented in Table 6.4.2-1. Additional details of the fuel qualification methodology are discussed in Reference 6.4.2-1, which is incorporated by reference in its entirety.
Special treatments for SR SSCs are initially selected as described in Section 6.3. Consistent with the RIPB iterative process described in NEI 18-04, as endorsed by Regulatory Guide 1.233, special treatment requirements for the fuel will be identified and selected following expansion of the design and PRA to align with the development of system-level reliability and capability targets. The applicability of any special treatment requirement to the fuel will then be evaluated with consideration for the specific RSFs performed by the system (see Section 6.4.2.1). The special treatment requirements selected for the fuel based on this evaluation will be described in the FSAR to be submitted as part of an operating license application.
As described in NEI 18-04, the selection of codes and standards supports both the plant capabilities for DID and the activities that contribute to programmatic DID. Thus, selected codes and standards inherently influence a baseline level of special treatment requirements.
Reference 6.4.2-1 provides the industry codes and standards that are preliminarily identified as applicable to the fuel.
6.4-23 Revision 0 SUBJECT TO DOE COOPERATIVE AGREEMENT NO. DE-NE0009040 Copyright © 2025 Long Mott Energy, LLC All Rights Reserved Long Mott Generating Station Preliminary Safety Analysis Report Based on preliminary design and safety classifications, the programs described in Chapter 8 and Chapter 12 are preliminarily identified as programmatic special treatments to be applied to safety-significant SSCs as appropriate. The NEI 18-04 process for special treatment selection is used to determine the extent to which these or other programs (e.g., Tables 4-1 and 5-7 of NEI 18-04) should be applied as special treatment requirements to SR components of the fuel.
Section 12.1.2 describes the process for verifying plant design features that are preliminarily identified as FOAK or unique.
References 6.4.2-1 X-energy, Xe-100 Topical ReportTRISO-X Pebble Fuel Qualification Methodology, Accepted Version, Revision 3, July 2022June 2023 (ML21246A289)(ML23160A294; public);(non-public) (ML23160A295; non-public)
Tables None Table 6.4.2-1 Periods of Performance for XPeRT and XPLoRE Scope of Work Period of Performance XPLoRE Testing Spring 2025 - Fall 2026 XPeRT Irradiation Fall 2025 - Summer 2026 XPeRT Disassembly Winter 2027 - Summer 2027 XPeRT Post-Irradiation Safety Testing Winter 2028 - Summer 2029 XPeRT Post-Irradiation Examinations Summer 2027 - Fall 2030