NSSC Allows Restart of 'Gori Unit 3' After Regular Inspection Completion

Confirmation of Safe Criticality Possible Based on Regular Inspection Results
Remaining Inspections Including Power Ascension Test Scheduled

[Sejong=Asia Economy Reporter Joo Sang-don] The Nuclear Safety and Security Commission announced that it allowed the criticality (restart) of Kori Unit 3, which underwent regular inspection starting July 14 this year, on the 19th.

Criticality is the state in a reactor where a nuclear fission chain reaction continues steadily, and the number of neutrons produced equals the number of neutrons lost, achieving neutron population equilibrium. Upon allowing criticality, the remaining nine inspection items, including the power ascension test (reactor characteristic test), will be conducted during or after the reactor criticality process.

The NSSC confirmed that the 87 inspection items to be performed before criticality during this regular inspection were completed, verifying that the reactor criticality can be safely achieved going forward.

Additionally, during this regular inspection period, a visual inspection of the internal containment building steel plates (CLP) (12 plates) and ultrasonic thickness measurements (69 plates, totaling 43,054 points) were conducted, confirming no abnormalities. The CLP is a steel plate that functions to prevent the leakage of radioactive materials in case of an accident.

The NSSC also focused on follow-up measures regarding the vulnerability of the isolated power system to salt damage caused by the typhoon that affected the Kori nuclear power plant site last September. As a result, Korea Hydro & Nuclear Power improved the overhead lines connecting to the switchyard (a facility that supplies the power generated at the plant to transmission lines) to prepare for typhoons, and it was confirmed that the equipment improvements meet the relevant technical standards.

Based on the results of the regular inspection so far, the NSSC has allowed the criticality of Kori Unit 3 and plans to finalize safety confirmation through subsequent inspections (9 items), including the power ascension test.

This content was produced with the assistance of AI translation services.