Nuclear reactor which produce delayed neutrons have half lives for their decay by neutron emission that range from milliseconds to as long as several minutes, and so considerable time is required to determine exactly when a reactor reaches the critical point. Keeping the reactor in the zone of chain-reactivity where delayed neutrons are "necessary" to achieve a critical mass state allows mechanical devices or human operators to control a chain reaction in "real time"; otherwise the time between achievement of criticality and nuclear meltdown as a result of an exponential power surge from the normal nuclear chain reaction, would be too short
Organic nuclear reactor of process heat instead of electrical power. It ran in this form until 1988. Indian officials have periodically expressed interest in reviving the concept. They initially received CANDU design materials during the period of the WR-1 experiment. To further lower operational costs, there have been several revivals of the WR-1-like concept. It is believed that an organic coolant purification system can be developed to handle the decomposition of the organic coolant, and research has begun to this effect. However, , no experimental system has been constructed. Organic nuclear reactor An organic nuclear reactor, or organic cooled reactor (OCR), is a