Japan Update: Cooling Resumed at Reactors 4 & 5 at Fukushima
First Published Saturday, 19 March 2011 03:20 am - © 2011 Need to Know News
--Updates With News of Resumption of Cooling in Reactors 4 and 5 --Work Continuing to Restart Cooling in Reactors 1 and 2 --TEPCO Expects to Connect Power to All Reactors by Sunday --Acceptable Radiation Level Raised After Workers Surpass Limit
TOKYO (MNI) - Tokyo Electric Power Co (TEPCO) has succeeded Saturday in restarting an emergency diesel generator and resuming the cooling functions in Reactors 4 and 5 in its Fukushima nuclear power facility as work continued to bring power to the other reactors.
Reactors 4 and 5 at the plant are set away from the other four reactors, which sustained the most damage in the massive quake and tsunamis on March 11.
Meanwhile, workers have succeeded in attaching a power cable to the crisis-hit Fukushima nuclear power plant and are now working inside to ensure success when they switch on desperately needed cooling machinery.
"TEPCO has connected the external transmission line with the receiving point of the plant and confirmed that electricity can be supplied," the plant's operation, TEPCO said.
It said workers inside the plant are now checking connections within it to ensure power does not short out once it is resumed. Their plan is to resume power to Reactors 1 and 2 before moving on to Reactors 3 and 4 by Sunday. Power is needed to restart water circulation systems that keep used fuel rods and reactors cool.
Water spraying continued overnight as officials worked to keep temperatures down in the cooling pond of the key Reactor 3, whose fuel rods contains plutonium, which is particularly toxic.
In an address to the Japanese people late Thursday, Prime Minister Naoto Kan said "the situation is very grave and I will share that quite honestly."
But he said "in the not so distant furtue the overall situation will be controlled."
Japan Nuclear and Industrial Safety Agency officials upgraded their assessment of danger at the plant to level 5 from level 4 on an international scale that goes to 7. The Three Mile Island incident in the U.S. was a 5 on that scale while Chernbyl was a 7.
Although elevated levels of radiation have been recorded outside the 30 kilometer exclusion zone around the Fukushima plant, the World Health Organization said Thursday that there is no major health risk outside the immediate area.
"The evidence so far, from radiation measured, we would say there is little danger there. There is little health risk for the public," said WHO spokesman Gergory Hartl.
The thoughts and prayers of the staff of the Nuclear Energy Institute are with our friends in Japan who have lost loved ones, homes and businesses during the earthquake and subsequent tsunami. We send our heartfelt sympathy and concern.
Latest NEI Updates
**NOTE: Refresh your Web browser periodically to ensure you receive the latest updates appearing on this page.**
UPDATE AS OF 2 P.M. EDT, SATURDAY, MARCH 19:
Radiation doses at the Fukushima Daiichi nuclear power plant continue to decrease. Radiation dose rates at the site boundary of the Fukushima Daiichi nuclear power plant ranged from 1 millirem to 3 millirem per hour on March 18. Eighteen locations were monitored in a 30-kilometer to 60-kilometer radius of the plant. The highest radiation dose rate at any of those locations was 14 millirem per hour.
Tokyo Electric Power Co. (TEPCO) is installing high voltage cables from a nearby transmission line to reactors 1 and 2 at Fukushima Daiichi. Power is expected to be restored to reactors 1 and 2 later today (Saturday, March 19, Japan time). Priority is being given to restoring power to residual heat removal and cooling water pumps at the reactors. Plans are being made to extend high voltage cables to reactors 3 and 4 by March 21.
TEPCO also is stepping up efforts today to add water to the used fuel pool at reactor 4.
Two diesel generators are running and supplying electrical power to reactors 5 and 6 at Fukushima Daiichi. A residual heat removal pump, powered by a diesel generator, is providing cooling to the spent fuel pool at reactor 5. Temperature in the spent fuel pool at reactor 5 is "high, but decreasing," according to Japan nuclear industry sources.
There has been no change in the primary reactor containment structures at the Fukushima Daiichi plant. Crews are still pumping seawater into the reactors 1, 2 and 3 to cool the fuel.
All four reactors at Fukushima Daini have reached cold shutdown conditions with normal cooling being maintained using residual heat removal systems......
Sunday, March 20, 2011
Tepco Reactors May Have Turned Corner As Some Cooling Functions Apparently Restored
TOKYO (Dow Jones)--The battle to bring the troubled Daiichi nuclear power plant in Fukushima Prefecture under control may have turned a corner, with cooling functions at two reactors apparently working again, a development that could ease a nuclear emergency that has gripped the nation for more than a week.
Plant operator Tokyo Electric Power Co. said it managed to get temperatures at the waste fuel storage pools at reactors No. 5 and No. 6 close to regular temperatures, Kyodo News reported Sunday morning. A typical spent fuel pool is kept at a temperature below 25 degrees Celsius under normal operating conditions.
The beleaguered Japanese utility said the cooling systems for spent-fuel storage pools have gotten back up and running again at its No.6 reactor, enabling the company to operate pumps that will supply seawater to the pools....