An alternative circulation system for the fuel cooling ponds used in Unit 2 began operations on May 31 and attempted to get a normal temperature around 25 º C on June 10. This work is expected to reduce the humidity inside the building, but this has not happened yet.
Address the issue separately in the unit's reactor, Tepco has conducted operations of air filters for ventilation Unit 2, and filter out air radioactivity. Then the filtered air is flowed back into the reactor building. The company said that it will continue for three days, then they will check again the existing radiation levels . If the internal level has dropped significantly, Tepco will open the door of the building so workers can go to work again.
For the first time since the accident on March 15, 2011, workers can now enter the third floor of the Unit 4 of reactor building. While the company is considering plans to install a new cooling pond system in Unit 4 because of the serious damages occurred.
(Source: World Nuclear News)