CX-270211: Radiation Monitoring and Seal System (RMSS) Stack Monitor and Damper Replacement

The Test Reactor Area (TRA)-770 Stack Radiation Monitoring System measures the air exhausted from the Advanced Test Reactor (ATR) for radioactivity and activates a ventilation shutdown if limits are approached or exceeded. Replacement parts are unavailable and age-related calibration difficulties have caused an increase in maintenance activities and system shutdown. This equipment is obsolete and needs to be replaced. The proposed action would replace the stack monitoring and activation equipment, including the detectors (gamma chambers), preamps, amplifiers, high voltage power supplies, source check equipment, signal cable, and relays. Improvements to the communication equipment would also be made by adding additional circuits or moving the current circuit closer to the stack breech.