RFI for U-10Mo Monolithic Fuel Fabrication Final.pdf

Request for Information RFI 966967

U-10Mo Monolithic Fuel Fabrication Revision 0 Date: 9/17/2026

1 Introduction The United States maintains a diverse fleet of nuclear research and test reactors (RTRs) that supports scientific research, nuclear technology development, education, national security, isotope production, and the qualification of fuels and materials for both existing and future reactors.

Unlike commercial nuclear power plants, these facilities are generally designed to produce neutrons rather than electricity. The U.S. Nuclear Regulatory Commission (NRC) currently regulates approximately 30 operating research and test reactors, most of them located at universities and colleges. In addition, the Department of Energy (DOE) operates several nationally significant research and test facilities, including the Advanced Test Reactor (ATR) at Idaho National Laboratory and the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Taken together, these facilities form a relatively small but strategically important research infrastructure supporting the U.S. nuclear enterprise.

The missions of these reactors vary considerably.

University reactors (2 are illustrated in Figure 1) are commonly used for nuclear engineering education, reactor-operator training, neutron activation analysis, irradiation experiments, and fundamental research. Larger national facilities provide capabilities that cannot readily be reproduced in smaller reactors. ATR, for example, contains dozens of irradiation positions and specialized test loops that can expose experimental fuels and materials to conditions representative of operating and advanced reactors. HFIR provides one of the world's most intense reactor-based neutron sources and supports materials irradiation, neutron scattering, isotope production, and neutron activation analysis.

Research reactors also support fields far beyond nuclear engineering; neutron beams are used to

The Massachusetts Institute of Technology Reactor is the only university reactor with a neutron flux and spectrum similar to a commercial light water reactor, and it is one of only two U.S.

reactors performing high-temperature materials irradiation experiments for nuclear power reactors. Courtesy:

Massachusetts Institute of Technology

The Missouri University Research Reactor is the only domestic research reactor used for routine production of radioisotopes and radiopharmaceuticals.

With internationally recognized leadership in radiochemistry, the University of Missouri holds a significant patent portfolio in nuclear therapies and leads the United States and the international community in generating new nuclear medicine treatments.

Courtesy: University of Missouri

Figure 1. Two of the more than 30 U.S. university-operated research reactors.

investigate materials, pharmaceuticals, energy-storage technologies, quantum materials, biology, and other areas of basic and applied science.

The U.S. RTR fleet is more varied than the commercial power reactor fleet, operating at different power levels and producing different neutron spectra consistent with their fuel geometry and experimental missions. Many university reactors are low-power pool-type, light-water reactors in which ordinary water provides cooling, moderation, and radiation shielding. At the higher-power end of the spectrum, HFIR is an 85-MW thermal, beryllium-reflected, light-water-cooled and moderated flux-trap reactor aimed at producing isotopes. An additional example is the 20 MW National Bureau of Standards Reactor, which uses heavy water (D₂O) as coolant, moderator, and reflector and is optimized for neutron science. Figure 2 provides an illustration of a fuel assembly used at the Missouri University Research Reactor (MURR) with its fuel plates, structural side plates, and nozzles. The fuel assembly designs are generally less than 1.2 m (4 ft) in length.

A new generation of research and test reactors is also being developed. The National Institute of Standards and Technology (NIST) is considering a compact 20-MW light-water-cooled and moderated core surrounded by a heavy-water reflector. ATR and the University of Missouri are also considering new reactors based on the current design but with increased capabilities. It is likely that the United States could add roughly 5–15 RTRs over the next two decades.

Outside the United States, research and test reactors constitute a geographically broad and technologically diverse fleet. As of 2026, the IAEA Research Reactor Database lists 228 operational research reactors in 54 countries, with a further 12 under construction and 11 classified as planned. These facilities range from small university training reactors to high-flux, multipurpose reactors exceeding 100 MWth, and are used for neutron-scattering research, radioisotope production, materials and fuel irradiation, nuclear education and training, and reactor-technology development.

On the basis of today's IAEA pipeline, Figure 2. The MURR U-10Mo fuel assembly with its structural side plates, upper and lower nozzles, and fuel plates. [2.]

Upper nozzle

Side plate

Fuel plates

Lower nozzle approximately 20–30 new research and test reactors could plausibly enter operation internationally over the next 20 years. The market for RTR fuel is steady and growing.

2 Background Information Production of the U-10Mo RTR fuel is generally divided into three major areas:

(1) production of the U-10Mo alloy, (2) fabrication of the fuel plates, and (3) fuel assembly fabrication, as illustrated in Figure 3 and described in the following subsections.

Figure 3. U-10Mo Fuel Fabrication Process Overviewi.

2.1 Production of the base U-10Mo alloy

The alloy production process begins with obtaining the required feedstock. For purposes of this process, the HALEU metal is provided as Government Furnished Material (GFM) in accordance with the Specification for Low-Enriched Uranium U-10Mo Fuel Fabrication, SPC-70872.ii Low-carbon, arc-cast molybdenum (ASTM B387-18, Type 365iii) feedstock is also required.

The uranium and molybdenum feedstocks are melted and mixed using vacuum induction melting (VIM) and cast into a blank. A final VIM process step is required to ensure that alloy trace impurities and characteristics are consistent with the fuel system requirements.

Alternative melting processes may require evaluation prior to acceptance.

Following casting, samples of the as-cast material are collected and analyzed, including mass spectrometry for metallic impurities and enrichment, and gamma or alpha spectroscopy for radionuclide analysis. The cast material is subsequently homogenized through heat treatment and/or breakdown hot rolling to achieve material uniformity, consistent with applicable U-10Mo homogenization practicesiv. Finally, the ingot is machined to the required length, width, and thickness (roughly 0.2 inches) to support the desired foil yield and roll-bonding process. The alloyed material, ingot, or billet may be surface-treated to prevent corrosion and stored indefinitely for later plate production.

Figure 4 illustrates the process.

2.2 Fuel foil and plate fabrication process

Figure 3 shows the baseline overall process flow and Figure 5 provides the general steps required for fuel foil and plate fabrication. The following subsections describe the process steps in more detail. A more detailed description of the process can be found in Schulthess et al.v

FeedStock •HALEU Metal •Low-Carbon

Arc-Cast Mo •U-10Mo Returns

Blank •VIM Cast

U-10Mo Alloy •Sample Alloy for

Acceptance •Hot Top Removal

Billet •Breakdown

Hot Roll

Ingot •Sized for yield •Sized for roll bonding •Cleaned for roll bonding

Figure 4. Alloy and ingot production process flow.

Figure 5. Plate Fabrication Operationsvi.

Figure 6 provides an illustration of the layers of material comprising the basic fuel plate used in the RTR HALEU fuel assemblies. Figure 7 provides examples of the plate arrangements in the fuel assemblies in a cross-sectional view.

Figure 6. Illustration of the layers of material in the U-10Mo fuel plate.

Al Cladding Zr Interlayer U-10Mo Fuel foil

Not to scale.

2.2.1 Fabricate Fuel Foil

The foil fabrication process begins with production of a master foil through hot co-roll bonding of the U-10Mo layer with zirconium interlayer layers. The zirconium material should conform to ASTM B352/B352M-17, Grade UNS R60001,vii with an oxygen content of less than 1,000 ppm.

An ingot is hot rolled to achieve a reduction in thickness greater than 15% during the first pass. Subsequent passes incorporate the zirconium interlayer to the foil with continued hot rolling to a thickness between 0.050 inches and 0.030 inches.

The resulting master foil is then cold-rolled at room temperature.viii, ix, x The cold-rolling process should achieve a thickness reduction greater than 10% and continue until the required final foil thickness is obtainedxi. A flattening anneal may be performed, as needed, to ensure adequate foil flatness for the subsequent cladding process; however, this step is optional. Following cold rolling the fuel foil is trimmed to the specified length and width.

Figure 7. Examples of fuel assembly plate arrangements (cross-sectional view).

Courtesy: Massachusetts Institute of Technology; University of Missouri; NIST; Idaho National

Laboratory; Oak Ridge National Laboratory.

2.2.2 Fabricate fuel plate

Figure 9 provides the plate fabrication process flow. The fuel plate’s aluminum cladding is bonded to the fuel foil with its zirconium interlayer using hot isostatic pressing (HIP).

Several plates are HIPed at the same time in a single HIP can and are separated from each other using strong backs that are coated with debonding agents. The HIP can is fabricated to specification using stainless steel (preferred) or carbon steel.

One side of the cladding is pre-machined with a pocket to accept the fuel foil. Strong backs, cladding sheets, and fuel foils are stacked into the HIP can. Once assembled, the atmosphere is pumped down to vacuum, and the HIP can is welded shut (remote electron beam [EB] welding is the current process used). The vacuum pump down operation must ensure removal of all air in the HIP can and prevent ice formation during pump down.

After welding, the HIP can is HIPed at approximately 560°C with an applied isostatic pressure of 103 MPa for 90 minutes to bond the cladding with the fuel foil. During this processing, the cans collapse and the plate is thinned. This process is essential to produce a good bond between the fuel foil and its cladding.xii xiii

Following HIP processing, the cans are inspected for process defects, and the flanges are cut off. The fuel plates are then removed and separated from the strong backs. If necessary, the fuel plates are sent through a roller leveler.

Fuel plate fabrication continues after the cladding is applied. The plates are polished using a wet process to their final thickness and sized to their final length and width. Ultrasonic and radiographic non-destructive examinations are performed on the plates prior to assembly, and final plates are inspected for length, width, and thickness. Foil width is controlled by calculated fuel loading, and the HIP process requires that the foil length be tightly controlled.

Master Foil •Hot Roll Bond Add Zr to U-

10Mo foil •Reduce thickness to

~ 0.03 inches thick •Assemble/disassemble hot pack

Child Foil •Cold Roll to final thickness •Anneal rework if needed

Finished Fuel Foil •Calculate fuel loading for width •Size length and width for final foil dimensions •Inspect Foil

Figure 8. Fuel foil production process flow.

2.3 Fabricate Fuel assembly

Following fuel plate fabrication and polishing, the plates may be curved to a specified radius if required by the specific fuel element design. The formed and polished fuel plates are then assembled into the fuel element by swaging them into pre-machined slots in the aluminum side plates. The resulting side plate and fuel plate assembly are welded to the appropriate end fittings, after which the end fittings are precision machined to achieve the required dimensional and interface specifications. Following final fuel element assembly and machining, a protective boehmite layer is formed on the exposed aluminum surfaces by hydrothermal treatment in high-purity deionized water under controlled autoclave temperature, pressure, and time conditions. The completed fuel element then undergoes final inspection to verify conformance with applicable dimensional, material, fabrication, and quality requirements prior to acceptance.

Plate Forming •Press plates to required curved profile (as required)

Element Assembly •Plate Swaging •End Fitting

Welding •Element final

Machining

Boehmite Application

Element Inspection

Figure 10. Fuel element assembly process flow.

Hot Isostatic Press Pack Assembly •HIP can and lid •Cladding, strongbacks •E-beam weld

Hot Isostatic Press •Diffusion bonding cladding to foil •Diffusion bonding cladding to cladding •Acceptance testing, Reverse Bend Test samples

Decanning Operation •Roller Level cans as needed •Open HIP Can •Roller Level plates as needed •Seperate Plates from strongbacks

Fuel Plate •Wet Polish to Final

Thickness •Size Length and

Width •non-destructive inspections

Figure 9. HIP plate fabrication process flow.

3 Equipment listing and estimated floor space requirements Table 1 provides an overview of the major pieces of equipment used in the fabrication process. At each of the process steps additional space is required to perform inspections of process materials. An estimate of the required manufacturing floor space is roughly 25,000 square feet, as illustrated in Figure 11. Some high-bay space (~30 ft ceiling height) will be required. Industrial scale utilities including 480V 3-phase electrical supply, compressed air, chilled process water, deionized water, ventilation, and argon will be required. The Greenfield Alternative Study by INL provides an excellent reference on facility requirements.xiv Floor loading, basements, and ceiling heights are machine specific;

however, general requirements may be found in the Greenfield Report.

Table 1. Equipment listing.

Major Process Equipment Quantity Description VIM Casting System 1 Make alloy and cast it into blank for further processing Breakdown Hot Roll

Takes blank and thermo-mechanically processes the blank them a billet, this refines the grain structure and eliminates the need for homogenization

Machining Center (Billet Sizing) 1 Takes the billet and sizes it, producing an ingot

Acid Billet Cleaning Center 1 Cleans the ingot for roll bonding and size reducing Hot Pack Assembly Cell 1 Assembles the carbon steel picture frame, U-10Mo ingot, Zr foils. Seal welds it.

Co-Rolling Hot Roll 1 Thermo-mechanically roll bonds the Zr to the U-10Mo and reduces the thickness to create a master foil Hot Pack Decanning Cell 1 Open the hot pack, remove the master foil for further processing Cold Roll 3 The master foil is cold rolled to final thickness and becomes a child foil Anneal furnace 1 If needed, the child foil is annealed for flatness Foil Sizing Cell 1 Child foil is cut into fuel foil sizes (A.2). Foil width is based on fuel loading calculation.

Foil Inspection Machine 1 Final foils are visually and dimensionally inspected, fuel loading confirmed.

HIP Can Assembly cell

HIP can is assembled, containing strong backs, Aluminum pocket plates, shims, and fuel foils. 4-6 foils are processed in a single can. Only extra thick plates are processed with 4 per pack; all other plates are 6 per pack

Electron Beam Welder 1 HIP can is electron beam welded prior to HIP

Major Process Equipment Quantity Description Hot Isostatic Press System

The aluminum pocket plates are diffusion bonded to the fuel foils and themselves creating the fuel plate.

The strong backs separate the fuel plates and prevent plates from bonding to each other.

HIP Decanning Cell 1 The HIP cans are opened and the plates removed.

Roller Leveler

The roller leveler is to help make sure the fuel plates are flattened and reduce internal stress. It may also be used prior to decanning if needed to assist in disassembly

Wet Polishing System

The plates are polished to final thickness. Each side is polished to help ensure fuel foil is centered in the plate profile. This process is monitored with a handheld ultrasonic system.

Digital Radiography System 1

The polished plates are x-rayed to locate the fuel foil within the plate (length/width). The location holes are punched in the plate for plate sizing.

Plate Sizing Cell 1 The plates are machined to final length and width.

Ultrasonic Inspection System 2 The plates are ultrasonically inspected for debond and cladding thickness.

Plate Forming Press 2 Plates are formed (if needed) into the proper curved shape.

Element Swager 2 Fuel plates are mechanically locked into the side plates via swaging.

Element Welding 2 The end fittings are welded to the assembled plates/side plates Element Final Machining 1 If needed, the end fittings are final machined Boehmite System 1 A boehmite coating is applied to the element Element Inspection System 1 The final element is dimensionally and visually inspected.

Date: 9/18/2026

Figure 11. Conceptual Equipment Layout.

U-10Mo Monolithic Fuel Fabrication Revision No.: 0

4 Request for Information Tasks In the past, many RTRs have been fueled with highly enriched uranium. The National Nuclear Security Administration (NNSA) Office of Reactor Conversion and Uranium Supply (ORCUS) has facilitated the development of a high-assay low-enriched (HALEU) uranium-molybdenum (U-10Mo) fuel for use in RTRsxv . As the new fuel is implemented, a commercial fuel supply is needed.

The overall market size for this fuel is about 10,000 plates and 200 elements per year and will consume 3,000 to 3,500 kg of HALEU metal a year. Based on current market estimatesxvi, the uranium metal costs are roughly $60M/y. The balance of the raw material costs is ~$12M/y. Assuming fabrication costs comparable to existing HEU fuel production and accounting for the substantially greater uranium mass and current higher unit cost associated with HALEU, the annual market value for supplying U-10Mo fuel to ATR, HFIR, NBSR, MURR, and MITR is preliminarily estimated at approximately $100–$175M.

The need for HALEU U-10Mo fuel is anticipated to exceed existing fabrication capacity in the mid-2030s timeframe. NNSA anticipates moving forward with supplier development beginning in the late 2020s.

NNSA is issuing this Request for Information (RFI) to gather information on industry interest and facility availability for HALEU fuel fabrication. The Respondent may be interested in (1) supplying the alloyed U-10Mo only, or (2) providing the fuel plate and assembly fabrication only, or (3) supply the alloyed U-10Mo and providing the fuel plate and assembly fabrication in the same facility (preferred).

4.1 Letter of interest outline

The Respondent(s) shall provide a written letter of interest (LOI) which includes the information requested in the tasks and requirements described in the paragraphs below.

The overall length of the LOI should be less than 20 pages and cover how the Respondent(s) would address requirements, as well as indicating the Respondent(s) experience level associated with each of the fabrication tasks. Responses should be marked as proprietary information as needed and will be handled as such.

NOTE: PNNL has distributed this RFI as a contractor to NNSA for ORCUS; Respondent(s) should assume that all LOIs will be reviewed by ORCUS and cognizant DOE/NNSA Federally Funded Research and Development Center contractors. As noted previously, proprietary or controlled information should be marked appropriately.

The Respondent may assume that technical support is available to establish the fabrication and inspection equipment and processes for all steps identified. Government provided equipment, materials, and processes are available to help provide a turnkey capability to the interested parties.

Teams of multiple companies are acceptable to address the areas of fabrication experience needed, for example, casting, rolling, HIP, radioactive material handling, etc. If transportation is needed to distant facilities, it should be noted in the response.

As a minimum, Respondents should provide the following information:

1) Organization name, address, contact information.

a) The organization’s non-binding expression of interest in fabricating HALEU U-10Mo alloy and/or fuel assemblies.

b) The year the organization was established.

c) A description of the organization’s ownership and physical location(s). Note that US businesses are preferred.

d) If applicable, the Contractor shall provide a written plan to address Foreign Ownership, Control or Influence concerns, including export control. This applies to both foreign owned/operated corporations and foreign owned US branch of a foreign owned corporation.

e) Organization capabilities, including number of available staff and physical assets that are usable for the anticipated work.

f) Description of the Respondent(s) team and experience with uranium fuel fabrication. Respondent(s) should also note any experience with handling and forming metal.

g) Interest area: (1) supplying the alloyed U-10Mo only, or (2) providing the fuel plate and assembly fabrication only, or (3) supply the alloyed U-10Mo and providing the fuel plate and assembly fabrication in the same facility (preferred).

2) Organization and key staff experience

a) Experience in nuclear material handling and fabrication; experience with commercial power reactors or research/test reactor fuel fabrication is preferred;

experience in reactor fabrication, radioactive material packaging and disposal, or similar products is acceptable.

3) The narrative should address the technical, operational, and management challenges associated with establishing a HALEU U-10Mo fabrication capability.

4) Existing Respondent facilities, planned Respondent facilities, or potential Respondent facilities suitable for fuel fabrication activities. A Nuclear Regulatory Commission Category II Special Nuclear Material (SNM) facility or Department of Energy Hazard Category III facility will be required.

a) Provide an estimate (in years) and relevant milestones defining when the facility can first receive equipment after a contract action.

b) An estimate (in years) and relevant milestones to an initial product demonstration.

c) If the facility is planned or potential, please provide a timeline indicating major milestones to facility commissioning. Address the planning and timeline required to acquire the necessary NRC or DOE facility license and receive SNM.

d) The Respondent(s) should provide a rough order of magnitude (ROM) cost estimate and timeline for facility development. Assume major equipment is provided by

NNSA.

e) Provide a description of how the Respondent (or Respondent’s team) leverages past experience with facility licensing.

5) Respondent’s approach to developing the U-10Mo fuel fabrication capability.

a) Outline the Respondent tasks required to establish the capability described.

b) A conceptual floor layout of major equipment pieces in the Respondent’s facility.

c) Considerations for related operations such as shipping and receiving, raw material and in-process material storage, destructive and nondestructive testing, in addition to setting up the dedicated fabrication line(s), and Respondent’s experience level with the identified operations.

6) Description of Respondent’s experience and approach for quality assurance and meeting Nuclear Quality Assurance NQA-1 requirementsxvii or equivalent.

7) Description of experience and approach for Environmental, Safety, Security, Health, and Radiological Programs. The experience and approach should cover elements such as:

a) Nuclear material control and accountability (NMCA) program

b) Criticality safety program

c) Physical security plan

d) Cyber security plan

e) Environmental plan (including waste)

f) Radiological health plan

g) Employee industrial health and safety plan

h) Waste disposal/treatment

5 RFI Schedule

• First round of questions to be provided to Battelle by Thursday October 1, 2026 with

Battelle to provide responses by October 12, 2026.

• Second round of question to be provided to Battelle by Thursday November 12, 2026 with Battelle to provide answers by November 19, 2026.

• The deadline for letters of interest is December 21, 2026.

6 Reference Listing i Hubbard, Lance & Arendt, Christina & Dye, Daniel & Clayton, Christopher & Lerchen, Megan & Lombardo, Nick & Lavender, Curt & Zacher, Alan. (2017). U-10Mo Baseline Fuel Fabrication Process Description.

10.13140/RG.2.2.28508.54400

ii Specification for Low-Enriched Uranium U-10Mo Fuel Fabrication, U.S. High Performance Research Reactor Project, SPC-70872, Revision ID: 0, 2/19/2024, INL iii ASTM B387-18, Type 365 Standard Specification for Molybdenum and Molybdenum Alloy Bar, Rod, and Wire, ASTM International iv Eutectoid Transformation in U10Mo Alloy: Effect of Deformation History and Homogenization Heat Treatment PNNL-28519 v Schulthess, Jason L., et al. “A Critical Review of the History of Fabricating Monolithic U-Mo Fuel Plates.”

Journal of Nuclear Materials, vol. 618, Jan. 2026, article 156220. Elsevier, https://doi.org/10.1016/j.jnucmat.2025.156220 vi Hubbard, Lance & Arendt, Christina & Dye, Daniel & Clayton, Christopher & Lerchen, Megan & Lombardo, Nick & Lavender, Curt & Zacher, Alan. (2017). U-10Mo Baseline Fuel Fabrication Process Description.

10.13140/RG.2.2.28508.54400

vii ASTM B352/B352M-17 (grade UNS R60001), Standard Specification for Zirconium Alloy Sheet, Strip, and Plate for Nuclear Application, with less than 1000 ppm oxygen viii Joshi, Vineet V., et al. The Effect of Rolling As-Cast and Homogenized U-10Mo Samples on the Microstructure Development and Recovery Curves. Pacific Northwest National Laboratory, July 2016, PNNL- 25781. https://doi.org/10.2172/1339909 ix Observation of grain growth in U-10Mo alloy, K Kalia et al 2019 J. Phys.: Conf. Ser. 1270 012029 x Cold Rolling Mill Requirements and Optimization PNNL Document number: PNNL-28758 xi Cold Rolling Mill Requirements and Optimization PNNL Document number: PNNL-28758 xii Adam Koziol, Kayla Yano, Alan Schemer-Kohrn, Ayoub Soulami, Vineet V. Joshi, Samuel A. Briggs, Elizabeth J. Kautz, Microstructure and microchemistry changes at U-10Mo fuel/AA6061 cladding interfaces with varying hot isostatic pressing conditions, Journal of Nuclear Materials, Volume 585, 2023, 154597, ISSN 0022-3115, https://doi.org/10.1016/j.jnucmat.2023.154597 xiii Rajib Kalsar, Nicole Overman, Taylor Mason, Miao Song, Timothy Roosendaal, Kenneth Johnson, Cody Miller, Curt Lavender, Vineet V. Joshi, Insight into the interfacial microstructure and chemistry of hot https://doi.org/10.1016/j.jnucmat.2023.154597 isostatically pressed AA6061-AA6061 bonds for U-10Mo fuel cladding application, Journal of Nuclear Materials, Volume 599, 2024, 155193, ISSN 0022-3115, https://doi.org/10.1016/j.jnucmat.2024.155193 xiv Greenfield Alternative Study LEU-Mo Fuel Fabricatio, Facility, INL/EXT-08-14577, July 2008 xv Reduced Enrichment for Research and Test Reactors (RERTR) [Nonproliferation] xvi https://www.thirdway.org/blog/how-much-does-it-cost-to-develop-new-nuclear-fuel-capacity xvii https://www.asme.org/certification-accreditation/nuclear-quality-assurance-nqa1-certification https://doi.org/10.1016/j.jnucmat.2024.155193 https://www.rertr.anl.gov/ https://www.asme.org/certification-accreditation/nuclear-quality-assurance-nqa1-certification

2.3 Fabricate Fuel assembly