“Levels of radioactive water rising despite efforts
The operator of the troubled Fukushima Daiichi Nuclear Plant continues to transfer highly radioactive water near a reactor to a storage facility.

Tokyo Electric Power Company says work has been underway since Tuesday to move 10,000 tons of highly contaminated water accumulated in the turbine building of the Number 2 reactor to an on-site waste processing facility. The water has been pumped into the facility at a rate of 10 tons per hour.

TEPCO says the toxic water level in a tunnel near the turbine building was 2 centimeters lower as of 6 PM on Wednesday. But it says because there was no change in the water level in the basement of the turbine building, the leaking of toxic water into the basement appears to be continuing.

The utility company also says the water level in a tunnel linked to the Number 3 reactor has been rising several centimeters a day for the past week. The water is expected to rise to about one meter below the ground level soon.
The company says water levels are also rising in the Number 5 and 6 turbine buildings.

TEPCO says an estimated 67,500 tons of contaminated water are now in the Number 1, 2 and 3 reactors alone, hampering efforts to restore the reactorsâ?? cooling systems.
The utility says at the Number 1 reactor, some cooling water poured in has likely evaporated.

Thursday, April 21, 2011 06:08 +0900
High radioactive levels detected in reactors
Robots have detected high levels of radioactivity inside the reactor buildings of the crippled Fukushima nuclear plant. The plant operator says the radioactivity must be reduced to allow work inside the buildings to bring the crisis under control.

Tokyo Electric Power Company surveyed the interiors of 3 reactor buildings on Sunday and Monday using robots equipped with dosimeters and cameras.
TEPCO says that over 50 minutes the robots found18.9 millisierverts of radioactivity in reactor Number 1 and 6.46 millisierverts in Number 2. The levels are hazardous to humans even over a short period. Levels of radioactivity were not available in the Number 3 reactor.”

(from:http://www.nytimes.com/2011/04/21/world/asia/21japan.html)

“Noriyuki Shikata, a senior government spokesman, had earlier issued an appeal asking people to stay out of the zone until the government gave legal force to an evacuation that had been voluntary until now. â??The situation at Fukushima Daiichi is still not sufficiently stable,â? he said. The 12-mile zone around the reactors was imposed in stages in the 30 hours after the earthquake and tsunami on March 11.

The government has also encouraged people to leave communities about 12 to 18 miles from the reactors as well as five towns farther away that happened to receive extra fallout because of wind and rain patterns.

Hidehiko Nishiyama, the deputy director general of the Nuclear and Industrial Safety Agency, said that the authorities were looking for ways to shore up the bottom of the spent uranium fuel-rod storage pool at Reactor No. 4 to prevent it from collapsing.”

Back in Japan, I’m relieved that the levels that the robots have found are not so high as to prohibit work, although the scheduling will still need to be very careful at present to keep workers’ doses down. Perhaps the robots will be helpful in this regard also. And Tepco have a plan to get to a safe and stable state, which while still rather vague at least has a good prospect of success within reasonable timelines.

I think that the Japanese government could consider adjusting the evacuation zone somewhat earlier than the six-to-nine-months timeframe they have floated, particularly to re-open those parts of the zone which did not receive significant radioactivity. (and which I take it were evacuated on a contingency basis).