Kori 3 and 4 Get Ten More Years: Nuclear Regulator Approves Continued Operation 5-2

A 5-2 vote on the second hearing

At its 17th meeting of the year the commission approved KHNP's licence change. Etoday reports the vote as 5 in favour and 2 against out of 7 members. The first deliberation was on Oct. 15; the decision came at the second.

The ten years are counted from the end of each unit's design life: unit 3 until September 2034, unit 4 until August 2035.

Nearly four years of review

KHNP filed its periodic safety review in September 2022 and applied for the licence change in November 2023. The Korea Institute of Nuclear Safety reviewed it from September 2022 to September 2026, and an expert committee examined the results for six months from March.

Not switching on tomorrow

Approval does not mean an immediate restart. KHNP must replace equipment to secure safety margins, and the commission must confirm it on site. The utility plans to bring the two units back one after the other in the first half of 2027.

Because the ten years run from the end of design life, the actual operating time is expected to be about 7 years for unit 3 and about 8 for unit 4.

What the dose assessment says

In normal operation the maximum resident dose is 0.096 mSv against a 0.25 mSv limit. In a major accident, including severe accidents, it is 103.3 mSv against a 250 mSv limit.

Busan's Gijang reactors, and who said what

Kori 3 and 4 are Westinghouse-designed 1,025 MW pressurised water reactors that began commercial operation in September 1985 and April 1986. Unit 2 was approved last November and may run to April 2033.

KHNP chief Kim Hoe-cheon said the extension will help meet rising power demand from semiconductors and AI. Commission chairman Choi Won-ho said it will check on site that the upgrades meet safety standards.