ML25325A204
| ML25325A204 | |
| Person / Time | |
|---|---|
| Site: | 07109372 |
| Issue date: | 11/21/2025 |
| From: | Travis Tate Framatome |
| To: | Division of Fuel Management, Document Control Desk, Office of Nuclear Material Safety and Safeguards |
| References | |
| TJT:25:020 | |
| Download: ML25325A204 (0) | |
Text
framatome November 21,2025 TJT:25:020 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Director, Division of Fuel Management Office of Nuclear Material Safety and Safeguards Washington, D.C. 20555-001
Subject:
10 CFR 71.95 - 60 Day Report - TN-B1 Certificate Not Followed
Reference:
(1) NRC Certificate of Compliance (CoC) USA/9372/B(U)F-96, Docket Number 71-9372.
Dear Sir or Madam,
Pursuant to 10 CFR 71.95(a)(3), Framatome Inc. (Framatome) submits this report for self-identification of instances in which multiple shipments of unirradiated fuel assemblies were made without fully complying with the conditions of approval in the Certificate of Compliance (CoC) for the NRC-approved Type B package. Framatome is the certificate holder for this packaging.
On October 9th, 2025, an internal investigation determined that three TN-B1 packagings (USA/9372/B(U)F-96) included a maintenance-replaced stud bolt that did not meet the required stainless steel grade. These TN-B1 packagings, serial numbers RA-039, RA-086, and RA-142, had a small number of stud bolts replaced between July 2020 and August 2024. The applicable material specifications are identified in licensing drawings FS1-0042698, Item 31, and FS1-0042703, Item 13.
Framatome has removed these three packagings from service and will be submitting a license amendment to allow the alternate material.
The attachment to this letter provides the required details for this report.
Please feel free to contact me at (509) 375-8550 or Bryan Flanagan of my staff at (509) 375-8537 if you have questions or need additional information.
Framatome Inc.
2101 Horn Rapids Road Richland, WA 99354 Tel: (509) 375-8100 www.framatome.com
framatome TJT:25:020 Page 2 of 7 Sincerely,
\ V~T " ~~"
l Timothy ate, Manager Environmental, Health, Safety and Licensing TJT/sm
Attachment:
10 CFR 71.95-Type B Transportation Package Report (USA/9372/B(U)F-96)
Cc: Haimanot Yilma, NRC Nishka Devaser, NRC Framatome Inc.
2101 Horn Rapids Road Richland, WA 99354 Tel: (509) 375-8100 www.framatome.com
framatome TJT:25:020 Page 3 of 7 Attachment 10 CFR 71.95 - Type B Transportation Package Report (USA/9372/B(U)F-96)
- 1. Brief abstract describing the major occurrences 71.95(c)(1)
The TN-B1 package is used to transport unirradiated fresh fuel assemblies, both channeled and unchanneled, with a U-235 mass percentage not exceeding 8.0 weight percent.
The drawings identified in the Certificate of Compliance, USA/9372/B(U)F-96, Revision 5, include in section 5(a)(3), drawings FS1-0042698 Rev. 1, Item 31, and FS1-0042703 Rev. 1, Item 13. These two items are M6 x 15L stud bolts specified as SUS304 stainless steel.
Three packagings, serial numbers RA-039, RA-086, and RA-142 had at least one stub bolt replaced as follows.
RA-039 maintenance on 08/15/2025 RA-086 maintenance on 10/26/2022 RA-142 maintenance on 07/02/2020 The replacement stud bolts were the same size but made of Type 302 stainless steel instead of the specified Type 304 stainless steel.
These stud bolts secure the bands that restrain the paper honeycomb shock absorbers within the outer container of the packaging.
There was no component or system failure that contributed to this event.
- 2. Narrative description of the event, 71.95(c)(2)
(i) Status of components or systems that were inoperable at the start of the event and that contributed to the event; There were no inoperable components or systems. The Item 31 and Item 14 stud bolts are used to secure the paper honeycomb shock absorbers.
(ii) Dates and approximate times of occurrences; The non-conforming material was identified on 10/9/2025. The dates the stud bolts were replaced were:
2101 Horn Rapids Road Richland, WA 99354 Tel: (509) 375-8100 www.framatonie.com
framatome TJT:25:020 Page 4 of 7 RA-086, 10/26/2022 RA-142, 07/02/2020.
(Hi) The cause of each component or system failure or personnel error, if known; A batch of 300 replacement stud bolts was received by Framatome on 07/01/2020. The purchase order correctly specified the Type 304 stainless steel material. However, the suppliers packing slip and certificate of compliance only indicated stainless steel. Framatomes receiving inspection did not identify the discrepancy, and the parts were installed during packaging refurbishment.
(iv) The failure mode, mechanism, and effect of each failed component, if known; Framatome identified the failure mode as human error, specifically:
Human Error or Inappropriate Actions Inattention to Detail Unawareness.
There was no adverse effect to the packaging due to the non-conforming material.
(v) A list of systems or secondary functions that were also affected for failures of components with multiple functions; No systems or secondary functions were affected.
(vi) The method of discovery of each component or system failure or procedural error; The non-conforming components were identified by during sourcing additional stud bolts. The Type 304 stainless steel is a special order material and with significantly higher cost than the commonly stocked Type 302, which led to the discovery of the discrepancy.
(vii) For each human performance-related root cause, a discussion of the cause(s) and circumstances; The root cause is attributed to human performance. Specifically, inattention to detail during receipt inspection allowed the installation of stud bolts that did not meet the material specification. The supplier documentation did not Framatome Inc.
2101 Horn Rapids Road Richland, WA 99354 Tel: (509) 375-8100 www.framatome.com
framatome TJT:25:020 Page 5 of 7 clearly identify the material as Type 304 stainless steel, as required by the purchase order.
(viii) The manufacturer and model number (or other identification) of each component that failed during the event; No components failed during the event.
(ix) For events occurring during use of a packaging, the quantities and chemical and physical form(s) of the package contents.
The TN-B1 packages (USA/9372/B(U)F-96) may be contain either one or two unirradiated fuel assemblies or up to 130 loose rods. The contents consist of solid uranium oxides or uranium carbide in fuel rods enriched to no more than 8.0 weight percent U-235.
The proper shipping name is typically: UN3328, Radioactive Material, Type B (U) Package, Fissile, Class 7, (2.2). The contents were solid uranium dioxide in fuel assemblies, uranium enriched to 20% or less. The subsidiary hazard (2.2) refers to the non-flammable helium gas used to pressurize the fuel rods.
- 3. Assessment of Safety Consequences and Implications of the Event, 71.95(c)(3)
There were no failures and no safety consequences associated with the non conforming stud bolt material. The three TN-B1 packagings are removed from service until compliance with the license is confirmed, either by removal of the non-conforming stud bolts or through a license amendment.
Type 302 and Type 304 stainless steel have very similar chemical compositions.
Type 302 may be produced with a chemical composition that falls within the Type 304 composition, effectively making the two steels interchangeable. However, in the case of these M6x15 studs, which are classified as Safety Category C-Minor impact on Safety, the chemical composition of the Type 302 studs was not supplied by the supplier during procurement.
The primary difference between these two stainless steels lies in the carbon content, with Type 302 typically at 0.15% maximum, and Type 304 at a lower 0.08% maximum. The higher carbon content in Type 302 increases tensile strength and hardness compared to Type 304 but can increase the risk of sensitization during welding.
Framatome Inc.
2101 Horn Rapids Road Richland, WA 99354 Tel: (509) 375-8100 www.franiatome.com
framatome TJT:25:020 Page 6 of 7 For stud bolt applications, Type 302 would be the preferable material, with higher tensile and yield strength, given welding concerns are adequately addressed.
Both Type 302 and Type 304 are austenitic stainless steels and are readily weldable using standard processes.
The higher carbon in Type 302 can increase risk of carbide precipitation (sensitization) at grain boundaries during welding. Sensitization occurs in 300-series stainless steels when chromium carbides (CnaCs) precipitate along grain boundaries, typically at temperatures between approximately 500-800oC (932 1472°F). This precipitation depletes chromium near the grain boundaries, reducing corrosion resistance and making the steel susceptible to intergranular corrosion (IGO), particularly in the heat-affected zone (HAZ) after welding.
Larger workpieces retain heat longer, increasing time spent in the sensitization temperature range. To mitigate these weldability concerns with Type 302, low heat input and controlled cooling should be applied.
The M6x15 stud bolts are stud-welded within TN-B1 containers. For the Type 302 studs welded in the three TN-B1 containers, minimal heat input would be expected due to the small size of the parts and welds, which helps reduce the risk of sensitization.
Using a stud welder, as defined and required in the container drawings, the heat input would be as follows for capacitor discharge (CD), short cycle, and full arc stud welding:
Process Type Heat Input Sensitization Risk Notes CD Stud Welding < 0.1 kJ/mm Negligible Ultra-short weld time Short-cycle Arc ~0.2-0.4 kJ/mm Low Good compromise Full Arc Stud ~0.4-0.6+ kJ/mm Low to moderate Rare for M6 studs For the estimated parameters typical for a stud weld, the heat input ranges from
<0.1-0.6+ kJ/mm, with typical heat input ranging from 0.2-0.4 kJ/mm. This range is generally acceptable for welding with minimal risk of plate distortion and low risk of sensitization.
For Type 302, heat input above ~0.7 kJ/mm should be treated as a threshold for increased sensitization risk. However, given the small size of the stud bolts, their Framatome Inc.
2101 Horn Rapids Road Richland, WA 99354 Tel: (509) 375-8100 www.franiatome.com
framatome TJT:25:020 Page 7 of 7 attachment to thin Type 304 plate with good heat transfer, and the use of a low-heat-input stud welder, the risk of sensitization is considered low.
- 4. Corrective actions taken, 71.95(c)(4)
All maintenance records were reviewed for the replacement of stud bolts. The three identified packaging were removed from service.
- 5. Reference to any previous similar events, 71.95(c)(5)
No previous or similar events have been identified related to this non conformance.
- 6. Contact, 71.95(c)(6)
Please contact Timothy Tate at (509) 375-8550 for any additional information regarding this report.
- 7. Assessment of Safety Consequences an Implications of the Event, 71.95(c)(7)
No individuals were exposed to radiation or radioactive material due to this event.
There was no leakage of contents due to the non-conformance, and no reduction in the performance of the packaging.
Framatome Inc.
2101 Horn Rapids Road Richland, WA 99354 Tel: (509) 375-8100 www.framatome.coni