31 Janvier 2015
January 31, 2015
Come March, it will have been four years since the triple meltdown at the Fukushima No. 1 nuclear power plant triggered massive leaks of radioactive material.
Work to remove unspent nuclear fuel from a storage pool at the heavily damaged No. 4 reactor building was completed at the end of last year as planned. Efforts to clear debris, a major source of radiation, from the wrecked nuclear plant have also made progress. As a result, the areas where workers need to wear full-face protection masks have narrowed.
These facts seem to suggest that the Fukushima cleanup work is finally beginning to move smoothly forward.
However, Tokyo Electric Power Co., the operator of the plant, said last autumn that operations to remove spent and melted nuclear fuel from the No. 1 reactor will be delayed by two to five years from the original schedule. Earlier this month, the embattled electric utility also said the disposal of radioactive water stored in on-site tanks will not be finished on schedule.
Behind these delays is the grim reality that existing technology and expertise is not up to the task of dealing with this unprecedented situation. Things are not going as planned in many ways.
The crippled nuclear plant still poses all sorts of risks and hazards to workers. TEPCO should place top priority on safety and steady progress in proceeding with cleanup work. What it must not do is adopt a slapdash approach in pursuit of accomplishing the task quickly.
Some 7,000 workers can be found on any given weekday at the Fukushima No. 1 plant, more than double the 3,000 or so that were there in April 2013.
The precise locations of the melted nuclear fuel rods of the No. 1 reactor are still not known, nor is their condition. Another unknown is from which part of the reactor the melted fuel can be removed.
First of all, technology has to be developed to ascertain the state of the nuclear fuel under the high levels of radiation.
TEPCO has decided to delay to fiscal 2021 the start of the removal of spent fuel from the No. 1 reactor. The work was originally slated to begin in fiscal 2019 under the road map for decommissioning that was unveiled in June 2013 by the government and TEPCO. Similarly, the start of the removal of melted fuel rods will be postponed to fiscal 2025 from fiscal 2020. The situation is more or less the same with the No. 2 and No. 3 reactors.
In September 2013, Naomi Hirose, TEPCO president, promised Prime Minister Shinzo Abe that the disposal of highly radioactive water would be completed by the end of March 2015. But only about 60 percent of the work has been done so far as a raft of problems, including glitches in equipment to filter out radioactive substances, caused delays.
There are special circumstances behind the individual cases of delay.
A worker at the plant died on Jan. 20 after falling into an 11-meter-high water tank during an inspection. The cause of the accident is under investigation.
The number of work-related accidents at the plant has increased significantly as TEPCO brought in more workers for cleanup operations.
The number of accidents in the current fiscal year, which runs through March, grew to 40 as of November, up sharply from 23 for all of fiscal 2013.
This troubling data raises concerns that safety management may have been put on the back burner under pressure to carry out tasks according to schedule. Errors that lead to accidents involving workers could also cause more cases of radioactive contamination.
Last week, the Nuclear Regulation Authority announced a draft medium-term timetable for efforts to reduce risks at the plant. The draft points out that the growing number of work-related accidents is a serious problem. It calls for a marked improvement in working conditions.
In order to make sure that cleanup work will be carried out safely and steadily, the NRA and the government need to provide appropriate support based on the actual conditions at work sites, which are often fraught with risks.
--The Asahi Shimbun, Jan. 30