JOIN USNorth Korea vowed in March to build such a reactor using its own nuclear fuel, and two American experts who recently visited the North have reportedly said that construction has begun.
Light-water reactors are ostensibly for civilian energy purposes, but such a power plant would give the North a reason to enrich uranium. At low levels, uranium can be used in power reactors, but at higher levels it can be used in nuclear bombs.
North Korea is pursuing an arsenal of atomic weapons, so all its nuclear projects are of intense interest to its neighbours and to the United States. Pyongyang carried out nuclear tests in 2006 and 2009, drawing international condemnation and UN sanctions.
The Washington-based Institute for Science and International Security yesterday released commercial satellite images from Nov 4 that show a rectangular structure being built, with at least two cranes visible at the complex. It estimated North Korea was constructing a 25 to 30 megawatt light-water reactor.
The institute based its estimate on information from the recent trip to Yongbyon by Siegfried Hecker, former director of the US Los Alamos Nuclear Laboratory, and Jack Pritchard, a former US envoy for negotiations with North Korea.
It said Hecker told the institute "that the new construction seen in the satellite imagery is indeed the construction of the experimental light-water reactor."
The institute said the amount of low-enriched uranium needed for a 25 to 30 megawatt reactor could vary "depending on the design of the reactor and whether it will be optimised for electricity production or weapon-grade plutonium production."
Officials at South Korea's foreign ministry didn't immediately respond to attempts for comment.
The new satellite imagery comes as the North presses for the resumption of international nuclear disarmament talks it quit last year. South Korea and the United States have said North Korea must show its sincerity before those talks can continue.