Fukushima: Thinking back from the end scenario
The end scenario for Fukushima is murky at this point in time. I tend to work intuitively: that is seeing the end state and working back to the present and then working out the steps to get from here to there. So let me try to do that in this somewhat long post. It has been suggested that I make longer posts and tell people my own viewpoints on FDL so that is why I am attempting this, since usually I go off one or two reports and give my opinion in a more scattershot manner.
I am writing this so that you will not be surprised or dismayed by what you read coming in the press over the next few years.
The End scenario as I see it
The current critical response will be ‘noisy.’ There will be many ups and downs. It is my hope at least that more catastrophic outcomes can and will be avoided. There are too many possible things to go wrong to imagine at this point – my suggestion is try not to focus on them.
The initial response will last for at least a year. The engineering effort to entomb the site will last several more years. The overall effect will last more than our lifetimes.
All six nuclear reactors will need to be entombed with sand, boron and cement, as was Chernobyl. All six spent fuel ponds will need to be emptied, the spent fuel will need to be entombed and will most probably be entombed at the same site. The entombment will need to be earthquake and tsunami proof up to level 9.0, the current earthquake/tsunami, at least. This will take several years to complete.
An “exclusion” zone will be set up in the area of the plant, at least to the 12km limit currently in effect, and I think, more probably to at least 20km radius. This will be a permanent exclusion zone. Radiological monitoring of the water, ground, seas and agriculture will need to be instituted in Japan as an ongoing and permanent effort. Medical assistance for radiological injury and cancers will increase over many years, particularly for the children affected.
The current situation
We have at least sixteen different areas of immediate concern and action needed:
- The six reactors,
- The elevated six spent fuel pools in the reactors,
- The polluted water in and around the plant,
- The ground pollution,
- The pollution of the seas, and
- The exclusion zone with both people and agriculture being affected.
The sheer number of foci of urgent attention is trying for the managers of this disaster. The carrying out of disaster recovery has to be done with attention to the long term impact on health of both the workers and the citizens affected, not to mention animals and crops.
The current critical response will be ‘noisy.’ There will be many ups and downs. It is my hope at least that more catastrophic outcomes can and will be avoided.
The Six Reactors
CNN has a good overview of what the current state is here. Since the situation changes daily I won’t recite that here but talk about the path from here to the end state envisioned. The fuel in the reactors will need to be cooled down to the cold storage temperature. The fuel in reactors 1, 2, and 3 may need to be stored permanently in place due to meltdown making it impossible to get it out of the containment vessels. If the containment vessels of 2 and 3 are damaged (as is suspected – see CNN cited above) then the only way to entomb them will be a massive concrete casket over the entire reactors.
For the reactors which are currently shutdown and undamaged the fuel may be taken out and stored outside of the reactors. The reactors in any case will need to be monitored long term for radioactive contamination of the physical structures. The structures may also be dismantled and entombed or entombed in place.
I believe the problem of the spent fuel is larger, and will be as urgent as the reactors themselves. The spent fuel amount is many times the amount in the reactors. I don’t think it is feasible to entomb the spent fuel in the fuel pools above ground level where they are in the reactors, but we’ll see what the engineers say.
The Scientific American estimated the amount of spent fuel at over 1800 tons:
The spent fuel pools are of significant concern, …the pools at each reactor are thought to have contained the following amounts of spent fuel…
- Reactor No. 1: 50 tons of nuclear fuel
- Reactor No. 2: 81 tons
- Reactor No. 3: 88 tons
- Reactor No. 4: 135 tons
- Reactor No. 5: 142 tons
- Reactor No. 6: 151 tons
- Also, a separate ground-level fuel pool contains 1,097 tons of fuel; and some 70 tons of nuclear materials are kept on the grounds in dry storage.
First order of business will be to cool the fuel assemblies in the elevated pools at each of the reactors to an extent that the rods may be moved. The problems of the spent fuel catching fire in the first few days occupied the response, and led to the televised helicopter water dumps and moving in of the fire brigades to spray water into the spent fuel pools where possible.
Generally the cooling of spent fuel takes a year. However, since Japan has the same problem dealing with spent fuel in a permanent way as the US – strong public reaction to storing it anywhere nearby – the spent fuel in fuel pools at Fukushima have been soaking for years.
After cooling the fuel is taken out and placed into so called dry cask enclosures and then placed in a permanent storage facility. Fukushima will need a long term disposal and entombment of these 1800 tons of fuel. My take on it is that this will be onsite, since any other disposal place will come under large reaction from the citizens.
There are several engineering steps to be taken. One of the most dangerous and urgent is getting the 160 tons of spent fuel out of the collapsed Reactor 2 and 3 fuel pools, prior to entombing those reactors. This will require moving the fuel, probably by sky lifting it out. So far it is not clear if any engineer has been able to get to there fuel pools to look into them, so the damage and subsequent effort needed to get to the fuel is unknown.
We have seen the reports of the leakage of contaminated water from the plant. This should have been expected from the wild efforts by spraying water onto the spent fuel. Now this water needs to be cleaned up. The tanks for contaminated water at the plant are already filled and it is not clear how the water can be contained.
Efforts will need to be put into place to stop the water from leaching into the ground water and getting into water supplies. I expect that this will be a major increase in bottled water usage in Japan.
Effort will be needed also to prevent the polluted water from going into the sea. I fear that this will be impossible since the normal storm drains will carry water outside of the plant to the sea easily.
Already there are no fishing zones, and no entry zones for seagoing vessels around the plant. There is a marked affect on seafood exports from Japan.
We will see in the future long term monitoring of the sea for a large area around Fukushima and monitoring of seafood from Japan. Expect the marketing machine to attempt to downplay the risk and to promote Japanese exports.
The Exclusion zone
The area around Fukushima is destined to become a no-man’s land like that around Pripyat near Chernobyl. I expect there to be a permanent exclusion zone of at least 12 km, and an area of no agriculture for a much larger area. The area will return to primordial woodland.
Cross posted at www.petraitis.us/blog/