(Mainichi Japan) June 18, 2011
Mountain of problems still remains before Fukushima plant brought under control
One cannot help but wonder how far efforts being made by the national government and Tokyo Electric Power Co. (TEPCO) to bring the Fukushima No. 1 Nuclear Power Plant under control have progressed.
Two months have passed since TEPCO first unveiled a roadmap for bringing the crippled plant under control, but various problems that have occurred since then show the roadmap was overly optimistic.
Uncertainty over the current state of the power plant and when it could be brought under control continues to disrupt the lives of locals.
Many people probably wonder whether the wisdom and power of Japan and the rest of the world are effectively being brought together and applied in the ongoing efforts at the plant.
The government and TEPCO recently announced updated roadmaps on bringing the Fukushima plant under control and supporting people affected by it, and they talked about how far measures in the roadmaps have been implemented.
However, they should also give a more general overview of the current situation of the nuclear power station and the outlook for stabilization of the plant, not just talk about specific measures.
It would also be good to give an updated assessment of the level of risk involving the plant.
At the Fukushima plant, of great concern now is how to treat radioactive water collected in the reactor and turbine buildings.
The massive volume of the water, which is estimated to be at over 100,000 cubic meters, is obstructing work at the plant, and if removal of the contaminated water is delayed, it could leak into the ground around the structures or into the sea.
TEPCO has been setting up a system that includes parts from French and U.S. makers to decontaminate the radioactive water and return it to the reactors, which would allow cooling of the nuclear fuel without bringing in water from the outside, which could leak and increase the amount of trapped radioactive water.
However, running of the system has been delayed after a water leak and other problems.
Further delay-causing problems could occur if TEPCO does not first ferret out and correct their root causes.
Furthermore, although the water circulation system has started now, how long should it be run?
It is also not clear what officials mean when they refer to stability of the plant, when we have not only a meltdown in the inner containment vessels, but the possibility of melted fuel having made its way to the outer containment vessels.
Dealing with the highly radioactive waste sludge that will be left after cleansing the radioactive water is another problem, and since Japan is encountering this and other issues with the nuclear disaster for the first time, work has had to start from the research and development phase.
According to the roadmap, TEPCO will aim to store the radioactive sludge and will evaluate the construction of shielding walls to keep radioactive water from contaminating nearby groundwater and nearby sea in mid-July or later, but the utility and the government should take quicker action.
Measures to minimize nuclear plant workers' exposure to radiation and improve their medical care have been incorporated into the updated roadmap and are important steps needed to support workers at the plant for the years to come.
Workers who had internal exposure to high levels of radiation were recently revealed, but it was months after their exposure.
The government and TEPCO need to speed up full measurements of workers' exposures to radiation and efforts to minimize their exposure.
Another problem is that the evacuation of residents near the power plant is still confused.
Although it is important to take care of residents near "hot spots" -- areas of relatively high levels of radiation including ones far from the plant -- the government also needs to give clear guidance to residents in areas that fall under designated evacuation zones while only having had low levels of radiation detected.
The central government and TEPCO may not have changed the time frames for their roadmaps, but the fact is that a massive number of issues remain to be addressed before the Fukushima No. 1 Nuclear Power Plant is brought under control.
毎日新聞 2011年6月18日 2時32分