via the-japan-news.com / April 11, 2105 / The government and Tokyo Electric Power Co. are studying three different plans to remove melted nuclear fuel from reactors at the crippled Fukushima No.1 nuclear power plant, it has been learned.
The Yomiuri Shimbun obtained a draft outline of an operation road map as well as a strategic plan on technical methods concerning the removal of melted fuel rods in reactors Nos. 1 to 3.
One of the options involves filling reactors with water. The other two methods don’t involve filling them completely with water because repairing possible leaks in the reactors could be difficult. The best approach among the three will be determined by the first half of fiscal 2018.
The government and TEPCO were to present the draft outline at a meeting to be held in Fukushima Prefecture on Thursday. A final draft will then be compiled based on the opinions of local residents, marking the second time for the road map to be revised following the first revision in June 2013.
To determine the progress of decommissioning work, removing melted fuel from the reactors is an important step. The government and TEPCO are aiming to start the process in 2020.
The plan currently favors the method of repairing potential leaks in the reactors, pumping in water and then removing melted fuel using robotic equipment from the top of the reactor. But the Nuclear Damage Compensation and Decommissioning Facilitation Corp., which provides technical advice, studied the method with others and concluded that filling reactors with water could be difficult in some cases.
To overcome the difficulties, the latest draft includes two other removal methods that will only pump in water at the bottom of the containment vessels and retrieve melted fuel through the air from the top or side.
Filling reactors with water could cool down melted fuel and block radiation. However, potential leaks would not have to be repaired if the reactors are not filled with water.
Source: The Japan News