nuclear-news

According to the USNRC: “The long-term accumulation of uranium in equipment with an unfavorable geometry, particularly in process ventilation and scrubber systems, has been a recurring issue throughout the nuclear fuel industry.”

The accumulation in an unfavorable geometry can lead to a criticality accident. At Toshiba’s Westinghouse Facility the amount of uranium exceeded the criticality safety evaluation (CSE) mass limit by over three times.

“A criticality accident is an uncontrolled nuclear chain reaction. It is sometimes referred to as a critical excursion or a critical power excursion and represents the unintentional assembly of a critical mass of a given fissile material,… In the history of atomic power development, 60 criticality accidents have occurred, including 22 in collections of fissile materials located in process environments outside of a nuclear reactor or critical experiments assembly“. https://en.wikipedia.org/wiki/Criticality_accident

“Criticality control should be part of an integrated program that…