In November 2010, this was in the early stages of construction. At the time, visiting U.S. experts described it as a “large excavated pit...roughly 40 meters by 50 meters by 7 meters deep” where “a concrete foundation 28 meters square with round concrete preforms for the reactor containment vessel was visible.” Construction apparently began in July 2010 with a target completion date of 2012, which Siegfried Hecker, one of the visiting experts, finds overly optimistic. The power level is expected to be 100 MWth with a conversion efficiency of 30 percent. The reactor will be fueled with 3.5% enriched UO2 fuel. [1] All components of the reactor will be manufactured indigenously. [2]

In light of the nuclear crisis in Japan in March 2011, many experts have expressed concerns about the safety of this LWR. [3] Peter Hayes of the Nautilus Institute for Security & Sustainability pointed out that it is “being built without regard to the international nuclear safety standards” and that North Korea’s “old and outdated electric power grid will not be able to handle the electricity generated from it.” [4]

Sources:
[1] Siegfried S. Hecker, "A Return Trip to North Korea's Yongbyon Nuclear Complex," Center for International Security and Cooperation, Stanford University, 20 November 2010, http://iis-db.stanford.edu.
[2] Siegfried S. Hecker, "Redefining denuclearization in North Korea," Bulletin of the Atomic Scientists, 20 December 2010.
[3] Ahn Jin-su, "북한 핵시설 안전성 문제: 일본 원전 사태를 계기로 살펴 본 시사점 [North Korean Nuclear Program Safety Issue: Implications in Light of Japanese Nuclear Crisis],한반도 포커스 [Focus on Korean Peninsula], Institute for Far Eastern Studies, Kyungnam University, Issue 13, May/June 2011.
[4] Lee Do-young, "영변 경수로, 국제적 기준 무시한채 건설 “北서 후쿠시마 원전 같은 사고 우려 [Yongbyon LWR Being Built without Regard to International Standards; Concerns about North Korean Nuclear Accident]", Kukinews, 11 May 2011, www.kukinews.com.