SUMMARY: RADIOCHEMISTRY ANALYTICAL TRACK 2 (ALPHA EXPANSION) Food safety can be threatened by radioactive contamination: isotopes that are naturally present in environmental samples in low abundance can reach dangerously elevated levels through nuclear plant malfunctions, radiotherapeutic accidents, terrorism, or even rare natural phenomina. The core tenet of this large and multifaceted proposal is to contribute a comprehensive and integrated food protection laboratory hub to the Food Emergency Response Network (FERN) that is capable of analyzing many different foods across a diversity of threat priorities. In addition to our capabilities, our goal relies on having the needed capacity to detect and identify a wide range of radionuclides in foods. Since the current FERN radiochemistry CAP grant is finishing its tenure in a few months, the Radiation section now seeks to be incorporated into the current multi-faceted cooperative agreement, and in doing so to expand its alpha spectrometry capacity by purchasing a second instrument and training additional personnel. This will strengthen and unify our involvement in FERN. Through this analytical track the laboratory will achieve the prescribed track Specific Aims.