Because overly cautious governments told them so.
The fact that they were not safe is disputed. There are claim that there was some over-reaction and that the evacuation was actually counter-productive.
And a really gossip comment comes from JDM car lovers that have gone to Fukushima and show abandoned cars with again unsafe radiation levels.
It is not easy to react to a possible nuclear disaster after a heavy earthquake anyways.
This was the great trick the environmental movement bulled, they made so much panic about radiation that acceptable amounts were lowered to absurd levels. This was all based on suds-science. If this science were even remotely true, people in Denver would by dying of cancer at incredible rates.
There are also lots of places that have more radiation because sand beaches (historically associated with healing sands). People living in that region for 100s of years should also suffer from higher cancer rates and don't.
There are still people in Germany flipping out about the fact that some mushrooms have 'unsafe levels of radiation' and yet lots of people eat them and it has no effect what so ever.
that is quite logical, scientific and consistent with approaches taken in relation to other biological hazards.
Radiation has two types of dangers, chronic and acute. Our understanding of what levels of radiation cause acute damage is pretty limited and not very precise since we simply don't have that much data. However, I highly doubt that anything close to those levels of radiation were measured anywhere outside the reactor complex.
In terms of chronic danger, the official stance is that there is no safe amount of radiation exposure and the general principle in managing exposure is ALARA (As Low As Reasonably Achievable). Lifetime cancer risk is cumulative so higher levels just add to that cumulative risk faster.
Thus there isn't really a clear "level of acceptable impact" but rather, we set arbitrary levels to to to limit that cumulative addition of cancer risk. Like with many things, that risk is a price you pay for other things that are important to you, like flying, living in denver, or getting xrays.
Spending a billion dollars to avoid a radiation caused cancer death is a very poor use of resources given you could save a hundred lives with other causes of death with that amount.
We learn and we improve for next time.
By comparison almost all superfund sites would have been dealt with for a tiny fraction of the cost and effort, assuming a similarly prompt response.
Not everything can be calculated so coldly! The gov absolutely has a responsibility to help people in an actual extreme situation like this versus the theoretical saving of people in future normal situations.
Even to this day, Fukushima-ken agricultural producers can't compete fairly on their quality, due to the lingering stigma with a half-life longer than any detectable isotope.
These lasting effects of hysteria are vastly worse for the health, prosperity, and wellbeing of the region than the actual becquerels released 11 years ago.
Out of 300k people 1,400 died over the span of 6 months [1]. Assume everyone lives to 100 and a uniform age distribution (both of these are actually generous: life expectancy is lower and age distribution skewed older in Japan), and 1500 people dying in 6 months is exactly on the mark for old age deaths. Even more telling, actually try and click on the link to the primary source in Mainichi Shimbun and it 404s.
1. https://www.nbcnews.com/news/world/fukushima-evacuation-has-...
That is nonsense. Most of that cleaning prevents nothing. Its mostly political posturing to show that they are doing something.
> Hundreds of people died during the evacuation
Evacuations that were mostly unnecessary.
With that said, I think even this old PWR design has actually proven itself to be extremely safe as it effectively prevented Chernobyl-style scenario during such rare and catastrophic event.
I mean, 3 reactors literally exploded, 3 cores melted and… pretty much nothing happened.
But it would be great to see new molten-salt fast reactor designs to gain traction, as they would be even safer, 95% more fuel efficient, not require water for cooling, and produce far less waste.
“According to MoltexFLEX, the cost of electricity generated by the FLEX reactor is comparable to that of wind, at just GBP40 (USD44) per MWh. This is achieved through a unique, patented system which uses two molten salts: one acting as a fuel, whilst the other circulates as a coolant. This allows the heat from the reactor to be extracted through natural convection, without the need for pumps.”
“Once online, the FLEX reactor can be operated with the same skills and equipment used in a fossil fuel plant. The reactor has no moving parts and is fuelled for 20 years at a time, meaning that there is very little operator input and very low ongoing costs.”
“MoltexFLEX estimates it would take just 24 months to build a 500 MW power plant. The company plans to have its first reactor operational by 2029.”
“The SSR-W is a molten salt reactor that uses nuclear waste as fuel. The company aims to deploy its first such reactor at the Point Lepreau site in New Brunswick by the early 2030s.”
The price in terms of deaths was low thankfully, but not because the released material was not dangerous, but because they have done an unprecedented cleaning project. 150k people had to leave their homes because they were not safe. Hundreds of people died during the evacuation, but if they had not been evacuated that death toll of one would have been higher too. Also, cancer can show up years/decades later, and linking it to radiation exposure might not be easy. Basically the dying with vs from covid discussion :).
This entire cleanup project is estimated to cost in the high three digit range of USD billions: https://en.wikipedia.org/wiki/Fukushima_disaster_cleanup#Cos...
Nuclear is safe if done right, but the Fukushima accident was definitely a big catastrophy, even if the death toll wasn't large.