A valiant, and perhaps last-ditch effort continued March 18 to pump tons of water onto crippled reactors at the Fukushima No. 1 nuclear power plant to cool storage pools containing spent nuclear fuel rods and spare Japan a possible radiation catastrophe.
A valiant, and perhaps last-ditch effort continued March 18 to pump tons of water onto crippled reactors at the Fukushima No. 1 nuclear power plant to cool storage pools containing spent nuclear fuel rods and spare Japan a possible radiation catastrophe.
Firefighting trucks used by the Self-Defense Forces were deployed around 2 p.m. They directed jets of water at high pressure at the No. 3 reactor.
Firefighters from the Tokyo Fire Department were also gearing up to join the effort.
A special rescue unit from the Tokyo Fire Department dispatched to Fukushima on March 18 was also considering how to contain damage at the No. 1 reactor using the same method.
Tokyo Electric Power Co., which operates the quake-damaged Fukushima plant, was also using two special firefighting vehicles on loan from the U.S. military.
The SDF abandoned plans to drop 7.5-ton buckets of water from the air as it did on March 17 and was focusing its efforts on containing a meltdown by strengthening its water-spraying operations from the ground.
One of the problems is that workers dare not edge too close because of high radiation levels at the site.
The outer building concrete layer of the No. 1 reactor was damaged on March 12 by a hydrogen explosion triggered by the Great East Japan Earthquake that hit the day before. That, however, did not trigger a major crisis.
Officials said the situation in the building remained comparatively stable.
When asked why the No. 1 reactor was targeted for intense water-spraying operations, Chief Cabinet Secretary Yukio Edano said at a March 18 news conference, “While the situation is not as serious as the No. 3 and No. 4 reactors, it will be important to increase the water in the pools (storing spent nuclear fuel rods) at each reactor as part of efforts to cool the rods.”
While the focus will be on spraying water on the No. 3 reactor by the SDF, work will also begin on dousing the No. 1 reactor with water, so long as that does not interfere with the SDF’s other mission.
As for the outcome of containment efforts on March 17 by the SDF, Edano said, “Since steam is being emitted (from the No. 3 reactor), we believe water is going to the pool, but we do not know for certain what volume of water is reaching the pool.”
The Tokyo Fire Department dispatched 30 firefighting vehicles and 139 firefighters to Fukushima. The vehicles include one with an articulating platform that is capable of discharging 3.8 tons of water a minute from a maximum height of 22 meters, a large hazardous materials vehicle that can spray up to 5 tons of water a minute and a vehicle with a ladder that extends to a height of 40 meters.
The other vehicles are able to continuously pump water at high volume, extend the length of hoses and measure radiation levels.
The three branches of the SDF planned to direct a total of 50 tons of water from seven firefighting vehicles from about 2 p.m. on March 18.
The previous night, the SDF used five firefighting vehicles to shoot about 30 tons of water from the relative safety of 80 meters or so.
Work to cleanse the firefighters and vehicles of radiation did not end until early March 18.
A high-ranking Defense Ministry official said, “The concentration of radiation was higher than expected, so it took longer to wash it away.”
While efforts were continuing on March 18 to restore electric power to the Fukushima plant, the work was not proceeding as smoothly as expected. Officials said the earliest that power could be restored was likely that night.
A total of 320 employees were dispatched to clear away rubble using bulldozers and lay cables.
Transmission lines have been laid to the nuclear power plant to supply electricity from Tohoku Electric Power Co., which provides electricity to Fukushima Prefecture. Electricity is already available at the transmission line.
Plans call for connecting the transmission line with cables about 1.5 kilometers in length to the various reactors.
A cable will first be connected to the No. 2 reactor, which had the least damage to the outer building. If the effort to supply power to the No. 2 reactor succeeds, electricity can also be supplied to the neighboring No. 1 reactor.
However, even if electric power is restored, there is still a possibility that large pumps and other equipment may not work properly because of damage from the earthquake and subsequent tsunami.
If the equipment is damaged, backup equipment will be brought in.
High radiation levels continue to be recorded around the Fukushima nuclear plant.
Measurements taken about 500 meters away from the No. 3 reactor where the SDF water-spraying work was conducted found a level of 3.63 millisieverts per hour at 7 p.m. on March 17 before the water-spraying work began. A level of 3.59 millisieverts was recorded at 8:10 p.m., immediately after the spraying was concluded.
In the wake of the problems at the Fukushima plant, the Defense Ministry and the SDF have raised the upper limit of accumulated radiation exposure for SDF members taking part in the emergency work from 100 millisieverts to 250 millisieverts. The revised figure means an SDF member can only remain near the crippled plant for a total of 70 hours. The conditions will become more severe the closer to the reactor core an SDF member approaches.