The Reserve Military Training Unit, which can augment the combat capability of the regular armed forces during contingency, is 600,000-strong. The unit maintains a level of training comparable to that of the regular armed forces. The status of the reserve forces in North Korea is shown in <Chart 1-7>: <Chart 1-7> north Korean Reserve forces Category strength Remark total approx. 7.62 million reserve Military training Unit approx. 0.6 million equivalent to rOK’s Mobilization reserve Forces (Men between 17-50 and women between 17-30) Worker-Peasant red Guards approx. 5.7 million equivalent to rOK’s homeland reserve Forces (Men between 17-60 and women between 17-30 who are not in reserve Military training Unit) red Youth Guard approx. 1 million Paramilitary units approx. 0.32 million advanced middle school military organization (boys and girls between 14-16) the Guard Command, Logistics Mobilization Guidance Bureau, etc. | strategic Weapons | To bolster its strategic attack capabilities, North Korea has continuously developed nuclear weapons, ballistic missiles, and chemical, biological, and radiological weapons. North Korea first gained access to nuclear materials in the 1980s after operating the 5MWe reactor located in the Yongbyon Nuclear Complex by reprocessing spent fuel rods. Later in October 2006, May 2009, February 2013, and January and September 2016, North Korea conducted five nuclear tests. North Korea is estimated to possess around 50kg of weapons-grade plutonium obtained from several rounds of reprocessing spent fuel rods. North Korea is also believed to have made significant headway in its HEU45) program. Its ability to miniaturize nuclear weapons also seems to have reached a considerable level. After beginning ballistic missile developments in the 1970s, North Korea produced and fielded Scud-B and C with ranges of 300km and 500km, respectively, in the mid-1980s. In the late 1990s, North Korea fielded the Nodong missile with a range of 1,300km, and later the Scud-ER, which extends the range of scud missiles. In 2007, North Korea fielded the Musudan missile with a minimum range of 3,000km without a test-launch. Through these successive additions to its missile inventory, North Korea has gained direct strike capabilities against ROK and the surrounding countries of the Korean Peninsula. As part of an effort to develop a long-range ballistic missile capable of threatening the con45) highly enriched Uranium. 32 Chapter 1 Changes and Challenges in the Security environment