By By Sravanth Verma Jan 29, 2015 in World U.S. security think tank 38 North has analyzed satellite imagery and surmises that North Korea may be restarting a research reactor to carry on atomic bomb research. Satellite imagery, between December 24 and January 11, shows signs of activity at the Yongbyon reactor, such as steam and melted snow on building roofs. "One possibility is that the North Koreans are in the early stages of an effort to restart the reactor after an almost five-month hiatus in operations," The 5-Megawatt research plant is The Washington-based Institute for Science and International Security think tank said that the purpose of the 2013-2014 shutdown may have been to fuel the reactor core, or undertake maintenance and renovation. Experts believe the facility North Korea is also known to have a Uranium enrichment facility, and is currently under sanctions over nuclear bomb and ballistic missile tests. The country had said earlier this month that it would suspend nuclear tests if the United States broke off annual military drills with South Korea. Washington rejected the proposal. The nuclear reactor may have been restarted to obtain Plutonium for atomic bombs, the think tank, which monitors North Korea at the Johns Hopkins University in Washington, said. The organization has however clarified that it is still too early to confirm this event definitively.Satellite imagery, between December 24 and January 11, shows signs of activity at the Yongbyon reactor, such as steam and melted snow on building roofs. "One possibility is that the North Koreans are in the early stages of an effort to restart the reactor after an almost five-month hiatus in operations," the think tank said . "However, since the facility has been recently observed over a period of only a few weeks, it remains too soon to reach a definitive conclusion on this and also on whether that effort is moving forward or encountering problems."The 5-Megawatt research plant is thought to have a few crude nuclear bombs, part of an effort to build capacity to threaten the United States mainland. The reactor went offline in 2007 after a disarmament agreement, but restarted again in April 2013, when the country announced it would develop deterrent capacity. A nuclear test was also conducted the same year. However, the facility was shut down in August 2014.The Washington-based Institute for Science and International Security think tank said that the purpose of the 2013-2014 shutdown may have been to fuel the reactor core, or undertake maintenance and renovation. Experts believe the facility could produce enough plutonium for one bomb every year.North Korea is also known to have a Uranium enrichment facility, and is currently under sanctions over nuclear bomb and ballistic missile tests. The country had said earlier this month that it would suspend nuclear tests if the United States broke off annual military drills with South Korea. Washington rejected the proposal. More about North korea, Nuclear weapons, Nuclear reactors More news from North korea Nuclear weapons Nuclear reactors