ATR Loop Pressurizer Fabrication

INTRODUCTION Battelle Energy Alliance, LLC (BEA), Management & Operating Contractor of the U.S. Department of Energy (DOE) owned Idaho National Laboratory (INL), is seeking an Expression of Interest (EOI) from qualified vendors capable of fabricating an ASME Section VIII, Division 2 pressure vessel for use as the ATR Loop Pressurizer (1A-NE Loop). The fabricated vessel will play a critical role in maintaining system pressure, degassing, and surge compensation for an Advanced Test Reactor (ATR) experiment loop. BACKGROUND INL is a U.S. Department of Energy (DOE) national laboratory dedicated to nuclear energy, national security, and clean energy innovation. The ATR experiment loops rely on a dynamic pressurizer system to maintain primary coolant pump pressure, provide a means of degassing the primary coolant, and compensate for pressure surges. BEA is requesting vendor capability statements for the fabrication of a vertically oriented, leg-mounted pressure vessel with radial side arms, built to strict nuclear, metallurgical, and structural performance standards. Project-specific INL drawings, design calculations, and procedural references will be furnished to selected vendors. The scope of work includes the following: Fabrication, inspection, and physical testing of one (1) ASME Section VIII, Division 2 stainless steel pressure vessel with associated appurtenances (vessel, mounting leg stand, spray nozzles, lifting lugs), per INL Drawings 1050604, 1050605, and 1050606 Supply of all materials associated with the vessel and appurtenances Hydrostatic testing at room temperature in accordance with ASME code (minimum test pressure 3415 psig, +100/-0 psig tolerance) Load testing and documentation of lifting lugs Shop drawing development and submission through INL's vendor data system Shipping/handling pallet and container for horizontal-orientation transport, forklift-compatible Delivery to WestOne Logistics, Idaho Falls, ID The scope of work does not include the following: Installation at the Contractor's facility Procurement and installation of clamp-on heaters Vessel insulation Design, seismic analysis, thermal analysis, stress analysis, or fatigue analysis Overpressure protection (provided by a separate direct spring relief valve) Floor mounting plate APPLICABLE CODES AND REFERENCES The fabrication and associated documentation must comply with the following (as applicable to component type): ASME Section VIII, Division 2 (2025) AISC 370 (2021) ANSI/AISC N690-18 (Nuclear Facility Steel Structures) ASCE 4-16 and ASCE 43-19 (Seismic Design) ASME NQA-1 (2022 edition) DESIGN REQUIREMENTS Vendors should have demonstrated experience with nuclear-grade pressure vessel fabrication and must meet or exceed the following design conditions: Materials & Components: Vessel and lifting lugs: Type 347 stainless steel Mounting legs: Type 316 stainless steel Vertically oriented, leg-mounted vessel with elliptical heads and four (4) radially arranged side arms Pressure & Temperature Ratings: Vessel Internal Design Pressure: 2500 psig Vessel Design Temperature: 668°F Normal Operating Pressure: 300–2208 psig; Normal Operating Temperature: 422–650°F Heater Leg Design Pressure: 2500 psig; Heater Leg Design Temperature: 800°F Vessel designed to Section VIII with seismic input per ASCE 4 and ASCE 43 (stand per AISC 370/N690) Fluid Service: High-purity, radioactive, demineralized water; pH range 5.0–11.0 Dissolved solids ?10 ppm, suspended matter ?3 ppm, chlorides ?0.5 ppm, dissolved gas ?150 cc/kg Cyclic Service: Pressurizer cycled between ambient and normal operating pressure 18 times/year over a 60-year design life (1,080 total cycles) Inspections & Engineering Approval: All pressure boundary welds (butt welds, with limited exceptions) inspected per ASME VIII/NDE requirements, including full volumetric inspection of all four side-arm weld joints Fabrication drawings and calculations submitted for formal BEA review/approval through the vendor data system PROCESS This EOI is the first step in identifying interested and qualified vendors. Responses may be used to inform the development of a formal solicitation list. Selected vendors may be invited to participate in a Request for Proposal (RFP) process for award consideration. SUBMITTAL REQUIREMENTS Interested vendors should submit an Expression of Interest that includes the following: Company name and point of contact Relevant fabrication experience, particularly nuclear or DOE-grade ASME Section VIII pressure vessel work Applicable NAICS codes and business size classification Any existing DOE or federal contracting experience (if applicable) Demonstrated capability to meet ASME, AISC, and seismic-informed design requirements Acknowledgment of the ability to meet the following vendor data submittals: Shop drawings and bill of materials Certified Material Test Reports (CMTRs) for weld filler material, spray nozzles, steel shapes/plates/piping Welding procedure specifications (WPS) and welder qualification/continuity logs NDE procedures, personnel qualifications, and inspection reports Lifting lug load test report Cleaning procedure and cleanliness report Internal/external surface finish reports Hydrostatic test procedure and report ASME U-1A Data Report As-built drawings Completed Vendor Data Schedule and transmittal forms (Form 431.13/431.14) QUALITY ASSURANCE REQUIREMENTS The subcontractor's quality program must be equivalent to ASME NQA-1 (2022 edition). Requirements include: Qualification records for welders, inspectors, and NDE technicians (including eye exams) Third-party inspection where required M&TE calibration records Certificates of Conformance (CoC) and ASME Pressure Vessel certification Submittal of all quality-related inspection and test documents FABRICATION & TESTING Materials must meet applicable ASME and ASTM specifications; Commercial Use (QL3) quality level per NQA-1 All pressure boundary joints are butt welds (limited fillet/stake weld exceptions for heater supports, trunnion plate, and spray nozzle attachment) Welds ground and polished flush prior to NDE Internal surfaces: 250 microinch Ra or better (except nozzles); heater leg exterior: 125 microinch Ra or better Cleaning to Class B cleanliness per ASME Code, both prior to final assembly and via final flush No paint on internal or external surfaces Hydrostatic testing per ASME Section VIII, Division 2 requirements BEA inspectors may witness fabrication and testing activities, withhold points specified at least 2 weeks in advance ASME "U" stamp certification of the vessel DELIVERY & PROTECTION Final vessel must be delivered to WestOne Logistics, 1765 North Yellowstone Highway, Idaho Falls, ID 83401, with: Vessel fully flushed, drained, and dried with no residual moisture prior to packaging Packed and shipped in horizontal orientation with suitable protective fixtures/fittings Clear labeling of purchase order number, gross weight, and lifting points Unit prepared for forklift handling; lifting diagram provided prior to shipment All shipping documents included in a waterproof envelope INL personnel retain rights for inspections, audits, and hold-point reviews throughout fabrication. Final acceptance occurs at the Subcontractor's facility prior to shipment and again upon arrival at WestOne Logistics. Deadline for submission: November 6, 2026 Submit to: Chase.egbert@inl.gov Only select respondents, as determined by BEA, will receive an invitation to participate in the anticipated RFP solicitation. PROPRIETARY INFORMATION Because information received in response to this EOI may be business sensitive or proprietary to the responding party, respondents must mark information in their responses accordingly.