INTRODUCTION Battelle Energy Alliance, LLC (BEA) Management and 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 providing tilting-disc style, 20-inch, 300-lb check valves for use at the Advanced Test Reactor (ATR). These valves are critical safety-related components used on the discharge side of high-capacity pumps and support safe operation of ATR. BACKGROUND INL is a U.S. Department of Energy (DOE) national laboratory dedicated to nuclear energy, national security, and clean energy innovation. The existing ATR check valves are original components with aging hydraulic dashpot systems. They have undergone numerous repairs, lack available spare parts, and are experiencing increased failure rates, warranting full replacement to maintain reliable reactor operation. The new valves must meet stringent design, operational, environmental, and safety requirements defined in INL Specification SPC-71414 (Rev. 0). SCOPE OF WORK Responding vendors must be capable of designing, manufacturing, testing, and delivering a quantity of four 20-inch, 300-lb tilting-disc check valves - complete with all components required for safe and reliable operation. Each valve assembly shall include: A 20” nominal, ASME B16.5 raised-face flanged, tilting-disc check valve constructed of ASTM A182 F304 or ASTM A351 CF8 stainless steel, with hard-surfaced or nitride wear areas. The check valve shall be designed and manufactured in accordance with the 2021 (or alternate year approved) ASME Boiler and Pressure Vessel Code Section III, Division 1, Class 1. An integrated hydraulic dashpot/dampening mechanism designed to achieve the specified closure timing. A position indicator assembly capable of transmitting valve position through standard industrial electrical signals. Valve configuration, dimensions, and functional characteristics consistent with INL Drawing 449559 or approved equal. Performance capability to operate within the limits for flow rate, pressure, temperature, closing time, pressure drop, disc stability, and leakage specified in INL Specification SPC-71414 (Rev. 0). Material compatibility with specified chemistry and radiation environment. Required testing and inspection, including hydrostatic pressure testing, nondestructive examination, and full operational testing for closure time, leakage, disc stability, and differential pressure. Complete vendor documentation, including dimensional outline and cross-section drawings, recommended spare parts list, and certificates of conformance. PROCESS This EOI is the first step in identifying interested and qualified vendors for future solicitation. 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 Express…