The Fukushima Daiichi nuclear plant was damaged in a tidal wave in 2011 and had to be shut down, but its live nuclear core meant that it had to be decommissioned. Now, new pictures suggest that the decommissioning may be more complicated due to unforeseen factors. Let’s delve into what these factors are.
A Disaster Forewarned
The Fukushima disaster occurred because of an earthquake and the following tsunami, which slammed into the plant and caused widespread damage. This was due to the plant’s construction.
A previous earthquake devastated the area in 1896, and TEPCO, the company running the plant, expected another one but didn’t submit their report because they didn’t consider it imminent.
Power Cut After the Earthquake
When a magnitude 9.1 earthquake hit the plant, reactors 1, 2, and 3 were immediately shut down. The plant was automatically disconnected from the power grid to ensure no damage.
The plant had three more reactors, but numbers 5 and 6 were undergoing routine maintenance and were already disconnected. Reactor 4 was defueled in 2010, so it was not at risk.
Backup Electricity for Cooling
Once power was cut to the plant, backup diesel generators were turned on to aid in cooling down the reactors. Unfortunately, the plant’s problems were only just starting.
A few aftershocks followed the main earthquake, but it wasn’t until the tsunamis crashed into the plant that the real trouble started. The first one hit the plant head-on, but no water came in.
Final Wave Causes Breakdown
Five more waves struck the struggling plant as it stood up to the endless assault from the sea. Some water had gotten into the plant, but it was still running normally.
The final wave, the height of which wasn’t recorded, ran into the plant and penetrated it, flooding the reactor cooling system and causing it to short out.
Series of Explosions Rock the Plant
The damage caused by the tsunamis led to several of the plant’s core systems failing. Eventually, pressure built up inside the reactor cores, and several explosions rocked the plant.
Radioactive material started to leak into the atmosphere and the Pacific Ocean around the plant, prompting officials to call for an evacuation until the situation could be rectified.
Not The Largest Nuclear Disaster Ever
While Fukushima was a severe nuclear disaster, it wasn’t the worst one on record. In fact, the damage done was far less impactful than other nuclear disasters on record.
The worst nuclear disaster to date was the explosion of the reactor core at Chernobyl. It was such a colossal disaster that the area around the plant has been unable to support life for more than fifty years.
Displaced Control Equipment Seen Via Drone Cam
To decommission the Fukushima plant, officials needed to determine what was still intact under the water. Some of the reactor cores are still flooded, so footage was taken with a drone.
The drone took 12 photos of Reactor No.1’s containment vessel, which is situated right under the reactor core. These photos revealed a series of displaced control rods at odd angles.
Leaked Core Material Needs to be Removed
Before the plant can be decommissioned, some 900 tons of radioactive core material needs to be removed from the damaged reactors. TEPCO is currently considering how to do this.
Officials had been hoping for a while to reach the core area where some of the radioactive material had leaked when the initial accident happened, but this was the first successful attempt.
Miniature Robots Are The Best Option
TEPCO had previously attempted to get visual data from the core, but its efforts were unsuccessful. The latest attempts utilized miniature robots, which managed to close the deal.
Radioactivity damages electronic circuits, so it was unsurprising that it took a specialized robot methodology to make it into the core and take the pictures that TEPCO needed.
Impossible To Tell What They’re Seeing
While the photos did offer color, it was still difficult for the experts looking at it to tell what they were seeing. The images displayed equipment or waste material, but it was impossible to specify.
Other data, including radioactivity, would be required to help them determine whether they were seeing core fuel or just broken and battered containment pieces.
Light Penetration Was Also Minimal
While the mini drones could get a good look at the reactor remains, they couldn’t see the bottom of the reactor containment vessel, even though they could successfully navigate there.
Light didn’t get to the bottom of the reactor containment chamber, and the drones didn’t have any light sources of their own. As a result, no one knows what’s happening in that part of the plant.
New Technology Needed for Removal
The core material is under seawater, complicating its removal and the cleanup that TEPCO must perform before it can decommission the plant. These photographs can help formulate a plan.
The probes can also serve as a prototype for technology that TEPCO will need to start the removal process since they can withstand radiation and harsh conditions.
Decommissioning Already Behind Schedule
TEPCO is facing an uphill battle with the decommissioning of this plant because of the unique situation the core is in. For the longest while, work couldn’t continue because there was no data.
Now, these pictures offer the company the first concrete data they have of what’s happening under the water in the core containment. New technology may need to be developed before removing the core material.
Will The Plant Ever Be Decommissioned?
The Japanese Government has given TEPCO between 30 and 40 years for the cleanup, but some experts think that this is a generous underestimation. As it stands, this bit of data is the first coming out of the collapsed plant.
Experts think it will take a long while before the requisite technology is developed to remove the core radioactive material from the plant and render it safe enough to decommission. Until such time, TEPCO doesn’t have the technology or the data to attempt what needs to be done.
