A Maintenance method for the exhaust valves on the alpha-tight hot cell under a ventilating condition

Mizukoshi, Yasutaka ; Kushida, Naoya 

On alpha tight hot cell under ventilating that has containment capability of nuclear materials, a safe and efficient maintenance method of exhaust valves which controlled negative pressure in hot cell was established at Fuels Monitoring Facility. The hot cell which required the exhaust valve maintenance needed to stop the ventilating during maintenance work because the valves could not be removed from operating exhaust system. And it was made known from prior work evaluation that this method involved long-term work, much costs and radiation waste, and large work risk. Therefore, a new method of valve maintenance under ventilating was needed due to the reductions of work period, costs and work risk.