The process of draining radioactive water out of the turbine halls of units 1-4 at the Fukushima Daiichi plant will be delayed for up to a week while workers check for cracks in a low-level waste treatment plant planned to receive some of the water, reports Japanese newswire NHK, in a document republished by the Japan Atomic Industrial Forum. Work to drain that store by pumping the water into the ocean was expected to end on Thursday 7 April.
A report from NHK suggests that there is still not enough space to store all of the radioactive water. TEPCO reports that at least 50,000 tons of highly radioactive water exists in turbine hall basements, trenches and tunnels. And any delay adds more problems, since 500 tons of water is pumped into the reactors every day for cooling.
TEPCO says it can store more than 60,000 tons of wastewater on site, by using the facility's built-in storage, and by installing makeshift tanks. The four reactors' turbine condensers have a total capacity of 10,600 tons (1600/3000/3000/3000). The four reactor condensate storage tanks have a combined total capacity of 9,400 tons (1900/2500/2500/2500). Two surge tanks shared by units 1-4 have a total capacity of 7,800 tons. And the waste treatment plant has a capacity of at least 10,000 tons (and at most 25,000 tons), bringing our best-case site total capacity to 38,000-63,000 tons, although many of these tanks are already partially filled with water). In addition, an offshore floating barge that TEPCO is planning to moor offshore has a capacity of 18,000 tons, although an earlier report suggested TEPCO would only be able to use half that storage space.
In other news, seawater radiation remains high near the damaged unit 2 reactor. Although a leak was plugged this week, on Wednesday 6 April a seawater sample still measured 5600 Bq/cc, according to NHK. Although the level is half that of the previous day, it is still 140,000 times higher than the legal limits. TEPCO said that it would be premature to conclude that the decrease was due to stopping the leak, NHK reported.
However, since the leak was plugged, water in a tunnel near unit 2 rose by 5cm over 24 hours from Wednesday morning to Thursday morning, TEPCO reported.
Fishing has been suspended in the province south of the Fukushima plant because of lack of demand, NHK reported. Brokers are refusing to buy fish from the plant. The Japanese government has begun monitoring fish in the region for radioactive contamination, partly to reassure consumers. Although samples of a small fish called sand lance were found to be contaminated above legal limits earlier this week, no other cases have been found as of Thursday afternoon.
(Editor's note: this article was modified 13 April 2011 to include the maximum capacity of the wastewater treatment plant, and qualification of the useful storage area in the offshore barge.)
FilesFukushima-Daiichi parameters 8 April Reactor-by-reactor, system-by-system summary from JAIF as of 8 April