After months of inactivity, North Korea has restarted construction of its new experimental light water reactor (ELWR). North Korea claims that the purpose of this construction is to help address domestic energy shortages, but it is also a critical aspect of efforts to produce nuclear weapons, according to a US-Korea Institute report. According to the report, commercial satellite photography from April 30, 2012 reveals that Pyongyang is nearing completion of the reactor containment building.After the reactor is finished, the next major step will be loading the heavy components, such as the pressure vessel, steam generator, and pressurizer. The report suggests that the components could be brought in through the cylindrical opening in the roof of the reactor containment building. How long this process could take is unclear, but the report posits a range of 6-12 months for completing those aspects of the reactor, and another 1-2 years before the new facility actually becomes operational.Previous analysis by 38 North, connected to the US-Korea Institute of Johns Hopkins, documented the rapid progress made on the ELWR in 2011. Nevertheless, after the site's turbine generator hall was completed in late December 2011, construction was temporarily stopped. The report adds that a February 3, 2012 satellite photo demonstrated no change in the volume of construction being performed at the site. The report provides no definitive answer as to why there was no major progress between December 2011 and February 2012, but it theorizes that the death of Kim Jong Il or the winter weather could both be responsible. Construction probably picked up again in March judging from a March 25, 2012 satellite photo which showed increased construction activity. The April 30 photo seems to show North Korea may now be close to finishing the reactor containment building. Steel rebar and concrete were added to the building's cylindrical wing which looks higher than in older photos. New construction has also been done on parts of the roof adjacent to that area. However, electronics must be hooked up in the control room. Also, North Korea will need to produce fuel assemblies before the reactor is operational. The report's overall evaluation is that the facility still may not be fully operational before 2014-2015.