The Nuclear Safety and Security Commission said it has completed all mandatory inspections that must be conducted before the first reactor criticality for Saeul Unit 3, located in Ulju-gun, Ulsan.
According to the Nuclear Safety and Security Commission, Saeul Unit 3 has gone through pre-operational inspection procedures since it received its operating license on Dec. 30 last year. Of these, all nine inspections that must be carried out before the first reactor criticality were recently completed, confirming that the reactor can safely reach a critical state.
Criticality of a reactor refers to a state in which a nuclear fission chain reaction continues stably. It is an important point at which the reactor enters the full-fledged operation phase as the number of neutrons produced and those lost are in balance.
Since the operating license, the Nuclear Safety and Security Commission has reviewed key items required in the pre-criticality stage for Saeul Unit 3, including the nuclear fuel loading inspection and high-temperature functional tests. The inspections confirmed that related equipment and functions meet the standards, leading to the assessment that the first reactor criticality can be achieved safely.