NSSC Allows Hanbit Unit 1 Criticality... Remaining Inspections Including Power Ascension Test to Proceed

[Sejong=Asia Economy Reporter Joo Sang-don] The Nuclear Safety and Security Commission announced on the 3rd that it has permitted the criticality of Hanbit Nuclear Power Plant Unit 1, which underwent a regular inspection.

Criticality refers to the state in a reactor where a nuclear fission chain reaction continuously occurs, and the number of neutrons produced equals the number of neutrons lost, resulting in a neutron population equilibrium.

During this regular inspection, the NSSC conducted tests on 86 items that must be completed before reaching criticality and confirmed that the reactor can safely achieve criticality going forward.

During the inspection period, the NSSC cut and examined the internal containment liner plate (CLP) located below the large penetration of the containment building and found three voids, for which structural integrity assessments and void repairs were carried out. The CLP is a steel plate that functions to prevent the leakage of radioactive materials in case of an accident.

Additionally, following the previous regular inspection, a follow-up check on the CLP thickness reduction revealed one area where the thickness was below the standard thickness (5.4 mm), and that section was replaced with a new CLP.

Furthermore, the NSSC visually inspected the reactor upper head and confirmed no signs of leakage such as boric acid precipitation on the surface of the upper head, and surface inspections of the welds on the outermost thermal penetration pipes (10 units) confirmed they were within allowable limits.

The NSSC plans to finalize safety confirmation through subsequent tests (10 items), including the power ascension test.

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