Japan: Nuclear Plant Problems In Units 3 And 4 Continue

Chief Cabinet Secretary Yukio Edano has described problems that occurred on the morning of 16 March with Fukushima Daiichi 3 and 4. He also outlined plans to pump water into unit 4.

At 8:34am local time white smoke was seen billowing out of Fukushima Daiichi 3. Efforts to determine the cause of this development were interrupted as all workers had evacuated to a safe area due to rising radiation readings. Readings from a sensor near the front gate had fluctuated for some time, although Edano said that on the whole there was no health hazard. Earlier in the morning readings had ranged between 600-800 microsieverts per hour, but at 10am readings rose to 1000 microsieverts per hour. Readings began to fall again from around 10:54.

Edano said that one possibility being considered was that the unit 3 reactor had suffered a similar failure to that suffered by unit 2 yesterday, although there had been no reported blast or loud sound, which had been the case for unit 2. The immediate focus, said Edano was on monitoring of levels and checking pumping operations.

It was not clear whether the increase in radiation readings were due to the problems today with unit 3 or the ongoing problems resulting from the damage suffered by unit 2, yesterday.

Edano also outlined plans for units 4. Preparations were being made to inject water into unit 4, however the high levels of radiation from unit 3 were impairing those preparations. When possible, the water injection would be done gradually as there were safety concerns over pouring a large amount of water at once. The water will be pumped into the reactor building from the ground, plans to drop water from a helicopter having been abandoned. Although he said that “all things were possible” Edano did not believe that recriticality at unit 4 was a realistic risk

Second fire at unit 4

Earlier, the Nuclear and Industrial Safety Agency said that a blaze was spotted in the reactor building of Fukushima Daiichi 4 at 5.45am local time this morning.

Attempts to extinguish it were reportedly delayed due to high levels of radiation in the area. A spokesperson for TEPCO said that by around 6:15am there were no flames to be seen.

The incident at unit 4 is believed to be in the region of a used fuel pond in the upper portion of the reactor building.

Origins

Tokyo Electric Power Company issued a notice of an explosion at unit 4 at 6am on 15 March. This was followed by the company’s confirmation of damage around the fifth floor rooftop area of the reactor building.

On that day, a fire was discovered but investigations concluded it had died down by around 11am.

At present it is not clear whether today’s fire was a completely new blaze, or if the fire reported yesterday had flared up again.

Researched and written by World Nuclear News