|Preparing to load at Echterdingen airport in Germany
Four more concrete pumping trucks are on their way to the Fukushima Daiichi nuclear power plant to help the effort to maintain fuel ponds.
Having overheated and suffered serious drops in water level, the used fuel ponds in the upper parts of damaged units 1, 3 and 4 were refilled by a number of ad-hoc means.
First came ineffective drops by helicopter, next was spraying from fire trucks. The situation was brought closer to control with the arrival of Hyper Rescue and Super Pump Truck from the Tokyo Fire Department, but it was an extra-large concrete pumping machine that has been most effective, particularly at unit 4 where steelwork obstructs spraying from the ground.
Tepco monitor the used fuel ponds of units 1, 3 and 4 and regularly spray seawater to refill them. At unit 2, where the top section of the reactor building is intact, it has used freshwater via a motor-driven pump. From time to time, steam is seen rising from the buildings.
In recent updates Tepco have said a malfunction with the pumps at unit 2 caused it to switch to fire pumps, and then a tear in a hose put this too on hold. There were no consequences from these interruptions.
The machine already on-site is a Putzmeister 58, named after the length of its boom in metres, supplied to Tepco on the initiative of Hiroshi Suzuki, director of Putzmeister Japan. It is able to pump up to 120 cubic metres of seawater per hour with fairly high precision thanks to a flexible boom. In earlier phases of the Fukushima accident, the ability to control the pumps remotely was a great help in reducing radiation doses to workers.
The site will soon receive delivery of two 62 metre units that were available from a Putzmeister factory in Germany and as well as two 70 metre units from the USA. The German machines were loaded and sent to Japan yesterday, while Putzmeister warned that arranging landing shipment for the huge Antonov cargo aircraft may take more time in the USA.
Researched and written
by World Nuclear News