This is a SOURCES SOUGHT NOTICE; there is no solicitation available at this time. No response will be provided to requests for solicitation. THIS SOURCES SOUGHT NOTICE IS PUBLISHED FOR MARKET RESEARCH PURPOSES ONLY. The Defense Threat Reduction Agency (DTRA) has a requirement as follows: DTRA is the Department of War (DoW) executive agent for the Nuclear Arms Control Technology (NACT) program which operates, maintains, and improves the majority of the U.S. portion of the International Monitoring System (IMS) is support of the United States Government (USG) and Department of War (DoW) objectives. The IMS was established to detect worldwide nuclear weapons tests via an extensive network that includes radionuclide, seismic, infrasound, and hydroacoustic monitoring technologies. The NACT program directly manages, operates, maintains, and improves these US IMS stations, involving primary and auxiliary seismic, infrasound, and radionuclide monitoring stations. Relevant to this Sources Sought Notice, the radionuclide technology includes aerosol particulate and noble gas systems. DTRA seeks a performer to operate and sustain the US IMS radionuclide monitoring stations, beginning August 2027. Each of these US IMS stations was designed and installed under supervision of the NACT program and according to the technical requirements specified in the relevant IMS Operational Manual. Each of these stations has also been formally certified. While the monitoring systems are standardized, each station has site-specific design considerations to optimize data quality, data availability, and improve long-term operations and sustainment. Following station certification by the Provisional Technical Secretriat (PTS), the configuration of each of the IMS stations has been strictly controlled and all changes in configuration since certification have been approved and documented according to the procedures outlined in the associated station operational manuals. The US IMS stations are operated in accordance with provisional operational guidance defined by the PTS for the entire IMS network of stations. The NACT program objective is for the radionuclide stations to continue to meet the operational requirement of 95% authenticated data availability that meets CTBT data quality parameters (such as peak resolution, energy calibration drifts or peak shape). [Note data quality is a measure of how well data from a monitoring station are within tolerances, have correct time, adheres to calibration and certification standards and are free of aberrations such as low or zero airflow rates, or spikes and gaps.] The US IMS station operations are generally automated and do not require a continuous daily on-site presence of a highly skilled station operator or engineer. The station operator should maximize the remote performance monitoring, troubleshooting, and repair of the stations. In general, the achievement and sustainment of a sufficient level US IMS station performanc…