Estimating Potential Tritium and Plutonium Production in North Korea’s Experimental Light Water Reactor

Abstract Our work explores North Korea’s 100 MW-th Experimental Light Water Reactor (ELWR) and its potential contributions to the country’s nuclear weapons program. Built at the Yongbyon Nuclear Research Center, the ELWR began operations in October 2023 and represents North Korea’s first attempts at a light-water reactor using domestically-enriched fuel. Our study examines possible configurations for energy generation, tritium production, and tritium-plutonium co-production. Assuming a single-batch core, the ELWR can be used to annually produce 48–82 grams of tritium, which can supply 2–4 new boosted warheads each year, up to a maximum arsenal of 88–150 warheads total. Concurrent production of tritium and weapon-grade plutonium is also possible but requires reprocessing of spent ceramic fuel. Overall, the findings underscore how North Korea’s nuclear capabilities may be advanced through the ELWR’s dual-use potential.