10 Mars 2017
March 9, 2017
NHK World's Ayako Sasa joins anchor Miki Yamamoto in the studio.
Yamamoto: The Fukushima Daiichi nuclear plant, on the Pacific coast more than 200 kilometers northeast of Tokyo, suffered one of the worst nuclear accidents in history after the March 2011 earthquake and tsunami. Workers are still struggling to contain the high levels of radiation and contaminated water there. Ayako, can you bring us up to speed on what's gone on at the plant since the disaster?
Sasa: The nuclear power plant is facing the ocean, and when the tsunami hit it caused massive damage to 4 reactor buildings and facilities. Three of them were damaged by hydrogen explosions, and reactors 1, 2 and 3 suffered meltdowns. To cool the reactors, water needed to be pumped in. They're still pumping water in today, and when it goes inside, it gets contaminated.
That water is then processed and is kept in storage tanks. There are around 1,000 of them. But what to do with all that contaminated water has not been decided. What's more, there's also underground water coming down from mountains in this direction and getting inside. Tokyo Electric Power Company is trying to prevent that water from getting in.
Yamamoto: This is where the ice wall comes in isn't it?
Sasa: That's right. Water runs down from the mountains to the ocean. It seeps through cracks in the buildings and it becomes contaminated -- tons of water floods into the buildings each day. The Japanese government and TEPCO decided to build an underground ice wall to block the water. They put long pipes into the ground and filled them with liquid coolant, which in turn freezes the soil between the pipes. The operation began last year and still isn't completed. The final part of the process needs approval and the nuclear watchdog is still studying what they think will happen when the wall is complete.
Yamamoto: The goal is to decommission the crippled plant. Can you talk about that process?
Sasa: Yes, when the meltdowns happened, nuclear fuel rods inside the reactors melted. TEPCO needs to find out what happened to that molten fuel and how much there is in order to figure out how to remove it. But here's the problem -- radiation levels are still too high for workers to get inside to see the damage for themselves. Because of this, they've sent in cameras and robots instead. Last month, the latest robot was sent in to measure the temperature, radiation and take pictures. It broke down and TEPCO gave up on it.
Yamamoto: Although research and development continue to get the answer, they still haven't found the exact location of the melted fuel rods and this is after 6 years. What's the timeline looking like for TEPCO?
Sasa: Decommissioning the Daiichi plant will take decades. And, the process is not only long but also complicated. The government and TEPCO are expected to decide this year on a broad outline for how to remove the melted fuel rods in. Their aim is to start removing it from one of the reactors in 2021, the whole process 30 to 40 years.
As for cost, the government says we can expect the price tag to quadruple from earlier estimates. That will bring things to about 70 billion dollars. The reason? The difficulty of the task and the lengthy period of time needed to do it. A project of this scale has never been done before.