Attachment No. 1 - FF-SOW-034 R0 Silicide Plate Demonstration 2.20.23.pdf

FF-SOW-034 R0 Silicide Plate Demonstration

Background The United States to reduce the use of high enriched uranium (HEU) seeks to enable the use of high assay low enriched uranium (HALEU) silicide fuels by expanding the fabrication windows for high density geometrically challenging fuel designs. In particular, a HALEU-based design of the inner fuel element (IFE) for the High Flux Isotope Reactor (HFIR) represents several technical challenges or the fabrication of fuel plates1.The IFE fuel plate design uses a symmetric airfoil shaped fuel zone with filler above and below to form a rectangular center. This rectangular center is then encapsulated in aluminum cladding. The current HEU IFE fuel plate uses die pressing of Al and U3O8 powders followed by hot rolling to form the fuel zone and bond the cladding. There is no current process for the fabrication of the HA LEU IFE fuel plates and an offeror may propose any practical manufacturing method(s) including additive manufacturing in place of die-press and hot rolling. Disruptive technologies coupled with proven manufacturing experience are especially encouraged. Technologies other than roll bonding may be proposed but may require additional qualification. The plates eventually are assembled in the involute IFE as described in reference 1. Details on the fuel plates for this activity may be found in the Attachments at the end of this statement of work.

The symmetric airfoil fuel zone has not been fabricated using the current HFIR dispersion fuel production line and new concepts are being sought. PNNL, in a phased approach, requests the offeror to provide a conceptual approach as well as demonstration articles for their approach for a HFIR IFE silicide production facility.

Phase 1 will focus on the fabrication of 3 proof of concept demonstration articles. These demonstration articles will be evaluated and destructively examined to compare the plates produced from the conceptual process to the targeted design. The information from this plate demonstration will be used to prepare for the fabrication of a small-scale production run of approximately 75 plates in Phase 2.

General Requirements:

• Process flow diagram and any proprietary process steps will eventually be provided to the

US vendor, BWX Technologies Nuclear Operations Group (BWXT-NOG) to fabricate. The offeror may propose a United States based partner not previously identified to produce the fuel elements.

• The process shall be scalable to a total of 7 usable IFEs per year (each element has 171 fuel plates).

• The proposed process may incorporate a clean sheet concept for fabricating rolling billets up to hot roll bonding (if hot rolling is required) as is not constrained to methods currently used for HEU HFIR fuel fabrication.

• Space is highly limited so the offeror should attempt to package their billet fabrication process in one (1) to three (3) glove box lines each with a footprint less than 4 meters long

1 J. W. Bae, B. R. Betzler, D. Chandler, G. Ilas, and J. L. Meszaros, “High Flux Isotope Reactor Low Enriched Uranium High Density Silicide Fuel Design Parameters,” ORNL/TM-2020/1799, Oak Ridge National Laboratory, March 2021.

by 2 meters wide by 3 meters tall. Overall footprint for the production area should be less than 100 square meters (including access and safety requirements).

• The offeror shall submit a detailed technology transfer plan for their approach to transfer the technology and/or production capability to BWXT-NOG after the conclusion of Phase 2.

The technology transfer plan shall include any licensing costs required.

• The offeror shall have an existing regulatory approval to process HALEU as required for a single plate (~100 g of HALEU) and a path (if not existing) to approval for HALEU for an IFE (~20 kg of HALEU) within 12 months of award.

• HALEU will be US Government provided material meeting specification Y/GNSS/05-05, Revision 4, “The Y-12 Standard Specification Low Enriched Uranium Metal Supply to Research and Test Reactors,” Y-12 National Security Complex provided in 100 to 300 gram broken metal chunks.

Work Scope The work scope is broken into 2 phases. Phase 1 is a proof of concept via the fabrication of individual flat plates (three required). The offeror is to provide a cost and technical proposal for Phase 1 only currently. A source selection committee of external and internal subject matter experts (SMEs) will evaluate the Phase 1 proposals according to the key performance parameters (KPPs) and Key System Attributes (KSAs). The KPPs and KSAs are provided along with the criteria.

Phase 1 Conceptual Design and Demonstration On a best-efforts basis fabricate 3 plates to meet specifications and drawing attached.

The Offeror shall provide as part of their technical proposal a Process Flow Diagram (PFD), including inspection plan, and recommended process to fabricate full size plates per the Attachments and cost proposal for the fabrication of 3 HALEU flat plates for proof of concept.

The PFD shall identify all major process steps required to fabricate the production quantities of plates (thousands per year). Each process step will have the necessary fabrication equipment and/or inspection equipment identified along with an estimate of the resources (i.e., labor hours) required for that step.

The PFD along with the technical approach shall be presented at a side meeting around the European Research Reactor Conference 2023 (RRFM, April 2023 in Antwerp Belgium. The presentations are tentatively scheduled for the Friday April 21, 2023 after the conference.

This presentation can be on-line and in person; with as much in person interaction as practical (key technical SMEs will be in person at the presentation to enable a detailed technical discussion).

NOTE: Some members of the source selection committee will participate virtually.

NOTE: The source selection committee will include subject matter experts from PNNL, Oak Ridge National Laboratory, Argonne National Laboratory, SCK/CEN, and subcontractor(s) to PNNL.

NOTE: The presentation shall not be open to the public and shall be limited to the source selection committee, sponsor (DOE federal employees and contractors) and the presenting offeror.

• The offeror shall provide examples of 2 successful projects making metal matrix composite (e.g. dispersion) fuel plates

Quality Requirements The offeror shall have an existing quality program for manufacturing of in-reactor experiments (e.g., NQA-1). A desk audit of the quality program may be performed prior to award. The offeror shall include in their technical proposal the quality plan for Phase 1. The offeror shall execute Phase 1 as a demonstration while developing a manufacturing and quality plan for Phase 2.

Quality requirements for Phase 1 at a minimum shall include the use of calibrated measurement and test equipment as well as laboratory notebooks providing documentation.

Deliverables and Schedule A. Presentation of Proposal for Phase 1 on the Friday (April 21, 2023) after RRFM 2023 including:

B. Phase 1 Conceptual Design and Demonstration

a. Three HALEU plates produced from the proposed process (Due 9 months after award)

i. One delivered to USHPRR via PNNL.

ii. The remaining two can be used for destructive examinations and inspections at offeror for use in delivering report.

b. A report of associated inspection and destructive examination data (Due 10 months after award)

i. Report to compare plates attributes against the specified requirements and drawing tolerances.

c. A report containing an updated PFD after 3 plates are fabricated (Due 12 months after award)

d. A report on viability of technology transfer logistics to BWXT (Due 3 months after award)

i. This report shall include license fees if applicable

e. Regular process reporting (Monthly)

f. Return of scrap (Due 18 months after award)

Attachment 1: Plate Design The plate design is based on that described in J. W. Bae, B. R. Betzler, D. Chandler, G. Ilas, and J.

L. Meszaros, “High Flux Isotope Reactor Low Enriched Uranium High Density Silicide Fuel Design Parameters,” ORNL/TM-2020/1799, Oak Ridge National Laboratory, March 2021 and key highlights of the plate geometry are provided below. Critical dimensions are taken directly from the design report and non-critical dimensions have been rounded for convenience. The plate is divided into 4 zones as described in the table below.

Figure 1 – Longitudinal Plate Cross Section (Red is fuel, yellow is filler, blue is cladding)

Table 1 – Plate Design Zone Description

Zone Description Fuel Section Profile

Axial Distance (cm)

Fuel Section Thickness

1 End Clad N/A 0 – 5 0 2 Taper transition Figure 3 5 – 6 Linear thickness transition from flat profile with t(µm) = 200 -> Zone 3 profile over 1 cm length

3 Fuel Section Figure 2 6 – 54 The fuel thickness curve fit to a six degree polynomial is: t(µm) = 0.0211x6 – 0.465x5 + 3.534x4 – 11.674x3 + 3.325x2 + 154.295x1 +

244.728 4 Bottom Fuel

Section Figure 3 54 – 55 Linear thickness transition Zone 3 profile -> flat profile with t(µm) = 200 over 1 cm length

5 End Clad N/A 55 – 60 0

Figure 2 Zone 3 Plate Cross Section2,9

Figure 3 Zone 4 Plate Cross Section7

2 J. W. Bae, B. R. Betzler, D. Chandler, G. Ilas, and J. L. Meszaros, “High Flux Isotope Reactor Low Enriched Uranium High Density Silicide Fuel Design Parameters,” ORNL/TM-2020/1799, Oak Ridge National Laboratory, March 2021.

9 The polynomial defined in Table 1 for Zone 3 defines the thickness of fuel in µm as a function of arc length in cm

Attachment 2: Plate Specification These specifications are adapted and simplified from reference (4) to support this demonstration activity. Final specifications will be different for actual fuel elements.

Fuel Zone Requirements

1. The matrix shall be unalloyed relatively pure Al meeting 99.95 purity.

2. The silicide shall be the U3Si2 phase and confirmed by X-Ray diffraction to be greater than 95%

3. The silicide shall have an average enrichment of 19.75 +/- 0.2 gU-235/g-total uranium

(NOTE: HALEU will be provided, and the process shall not change the bulk enrichment)

4. The burnable absorber shall have 2.13 +/- 0.01 grams of 10B uniformly distributed in the

Al matrix (this can be in the form of B4C, AlxBy, naturally occurring B or 10B).

5. The fuel zone within the burnable absorber and clad shall have 26.56 +/- 1 grams of U-

235.

6. The volume percentage of U3Si2 shall not exceed 45% in the fuel zone.

7. If the fuel zone is made by powder metallurgy the Al or U3Si2 powder may be any size distribution or morphology provided the fuel powder in the finished plate is relatively homogeneously distributed.

a. Homogeneous is defined as a local area fraction variation of less than 50% over any 0.5 x 0.5 mm spot and a full fuel cross-section variation of less than 15% (including thickness variation).

8. If the fuel zone is made by a non-powder metallurgy process the fuel in the finished plate shall be relatively homogeneously distributed.

a. Homogeneous is defined a local area fraction variation of less than 50% over any

0.5 x 0.5 mm spot and a full fuel cross-section variation of less than 15% (including thickness variation).

9. The fuel zone shall follow the profile as shown on the drawing within 8% of the overall thickness

10. The fuel zone volume is considered the integral under the curves shown in Figures 2 and 3.

Plate Requirements

1. The cladding alloy shall be B209 6061 aluminum or buyer approved alternative.

2. The final plate shall have a surface roughness Ra of less than or equal to 1.6 micrometers measured along perpendicular to the length and width of the plate over the plate

3. A follow-on qualification of the processes will be required.

a. If hot rolling is used to bond the 6061 cladding with rolling temperature above

400oC and a reduction of 6:1 or greater may not require a process specific qualification.

4. The thickness of the plate shall be held to 5% of the overall thickness

5. The fuel zone (filler + fuel section) shall be centered within the Al cladding.

6. Physical Dimensions (tolerance is +/- 5%)

a. Clad Minimum Thickness 254 µm

b. Fuel Zone (Filler + Fuel Section)3

i. The fuel zone is considered centered in the fuel plate

ii. Length 50.00 cm

iii. Width 8.00 cm

iv. Thickness 762 µm

v. The fuel section is considered centered axially in the fuel zone

1. 0.50 cm of cladding can be assumed on each end so the fuel zone

2. x in zone 3 starts at 0.00 cm of the fuel plate

3. the volume of the fueled zone is the integral from x = 0.50 to x =

8.50 cm

vi. The filler is considered centered axially in the plate

1. The volume of the filler zone is the volume of the Fuel Section – the volume of the fueled zone

c. Fuel Plate

i. Length 60.00 cm

ii. width 9.00 cm

iii. Thickness 1270 µm

d. Minimum bend radius (information only)

i. 6.90 cm

3 The filler is yellow in Figures 2 and 3, the fuel section is red in Figures 2 and 3.