[5][1] As the center has not received fresh fuel since Soviet times, this reactor is now[needs update] (February 2007) only run occasionally for experiments or to produce isotopes, particularly iodine-131 for thyroid cancer radiation therapy.

Following the breakdown of the Agreed Framework in 2002, operation restarted in February 2003, creating plutonium within its fuel load at a rate of about 6 kg per year.

[11] Nyongbyon is also the site of a 50 MWe Magnox prototype power reactor, but construction was halted in 1994 about a year from completion in accord with the Agreed Framework, and by 2004 the structures and pipework had deteriorated badly.

[10] On 13 February 2007, an agreement was reached at the Six party talks that North Korea will shut down and seal the Magnox nuclear reactor and associated facilities and invite back International Atomic Energy Agency personnel to conduct all necessary monitoring and verifications.

[13] In return for this North Korea will receive emergency energy assistance from the other five parties in the form of 50,000 tons of heavy fuel oil.

International Atomic Energy Agency (IAEA) inspectors arrived at the site on 28 June to discuss verification and monitoring arrangements for the shutdown.

[20] On 27 June 2008 North Korea destroyed the most visible symbol of its nuclear weapons program – the cooling tower at its main atomic reactor in the complex.

[21] The demolition of the 60-foot (18 m)-tall cooling tower, which carried off waste heat to the atmosphere, is a response to U.S. concessions after the North delivered a declaration of its nuclear programs to be dismantled.

[23] According to the state-run North Korean news agency KCNA website, the DPRK resumed the reprocessing of spent fuel to recover plutonium on 25 April 2009 in response to the UN's condemnation of its recent rocket launch.

[24] In 2009, North Korea announced its intention to build an indigenous experimental light water reactor (LWR) and the uranium enrichment technology to provide its nuclear fuel.

[29] In 2017, several activities were noted involving construction, a dam was built to provide sufficient amount of water for cooling system, a switchyard and connections to transmission line were made along with facilities presumably used for maintenance and repair.

[34] In February 2012, North Korea announced that it would suspend uranium enrichment at Nyongbyon, and not conduct any further tests of nuclear weapons while productive negotiations involving the United States continue.

[38] On 15 September 2015, North Korea announced that the Yongbyon nuclear site is in full operation, including the 5 MWe experimental reactor.

[43] However, in August 2021, the International Atomic Energy Agency reported that North Korea appeared to have restarted the 5 MW reactor.