In both the Fukushima and Chernobyl incidents, widespread contamination would have been prevented had both facilities been enclosed within a larger structure. While existing plant designs call for hardened structures for the reactor itself, they often don't contain secondary and support infrastructure (Fukushima) or are insufficient to contain more explosive incidents (Chernobyl).

I'm curious if existing plant designs could be augmented with the addition of a large, non-hardened, dome structure that covers the entire plant. The dome would be able to contain escaped gasses simply by being hermetically sealed - and a sufficient distance between the dome and any potential sources of explosions means there's enough normal air to buffer and absorb the explosive shockwave, if any.

Such a structure could be built very cheaply - a geodesic hemisphere, for example, constructed of plastic links with inward-opening transparent plastic panels for natural light and ventilation. A fail-safe system would automatically close all panels to prevent the escape of unwanted gasses after an explosion.

There is some precedent for this, insofar as how's Chernobyl's reactor complex is now enclosed within the New Safe Confinement structure - except it's an ugly, opaque, and very expensive structure, constructed in a dangerous environment. Presumably my dome proposal could be built cheaply - and the cost/benefit of construction vs clean-up costs (multiplied by actuarial risk) make it a straight-forward decision - and given human penchant for safety theatre it would help "sell" nuclear power to the masses, but that is beyond the scope of my question.

So my engineering questions are:

  • How big would a dome or other enclosing structure have to be in order to enclose all of a plant's at-risk structures?
  • And wold the volume of air inside the dome be sufficient to buffer an explosion to eliminate the need to excessively harden or reinforce (and so, add weight) to the dome structure?
  • Assuming that all of the panels in the dome structure are capable of opening and used for ventilation, would that be sufficient to prevent a greenhouse effect?
  • In your opinion, is this proposal feasible or realistic?
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    $\begingroup$ Your question seems to focus on the release of just radioactive gases from failed/exploding nuclear power plants. There are other sources of radiation from exploding nuclear plant that can be more dangerous. A light weight dome like you are suggesting would have to be huge & cover a vast area, effectively preventing the land from used for other purposes. "Plastic links", as you suggest, would not have the strength required for a huge dome. Such a dome will not prevent ground water contamination & will be totally ineffective against radiation escaping from the nuclear core. $\endgroup$
    – Fred
    Commented Jul 31, 2017 at 2:41
  • 1
    $\begingroup$ Bird's egg shells work very well at stopping stuff from outside getting in by breaking the shell, but don't stop the chick inside getting out by breaking it. Your dome idea would have the same basic defect. $\endgroup$
    – alephzero
    Commented Jul 31, 2017 at 2:48

2 Answers 2


Chernobyl did not have a containment structure which was Russian practice at the time. The graphite moderator caught fire which was very difficult to control without containment. The heat from the fire carried the radioactive ash material high into the atmosphere causing the extreme area of contamination. I doubt anything would contain a nuclear explosion. And completely unrelated: Russia had some nuke power plants that used once through water instead of separate reactor and turbine water sections . This caused a low but steady release of radioactive materials. Again showing Russia had a different perspective.


It is feasible and realistic. It was already build many times:

enter image description here enter image description here

This structure has likely a positive effect to the public opinion. It could have defended the region against the Chernobyl and Fukushima disasters. And it had been much more cheap as building this after an event.

The probable reason, why there is no such sphere around all currently built reactor is some similar as there are no catapults in passanger airplanes. Safety is reached on different ways. The balance between the

  • public opinion
  • costs
  • and safety

reasons are simply not for build them. But they could be.

Note: maybe integrating the concrete of the sphere into the reactor building (i.e. building it with thicker walls and with more complex safety mechanisms) could reach the same goal.

  • $\begingroup$ Interesting pictures. As far as I can tell, the first picture is of "Chinon Nuclear Power Plant and Reactor" in France, and the second is "Yankee Rowe Nuclear Power Station" in Massachusetts. The Yankee Rowe plant was shutdown in 1992 after operating for 32 years. The Chinon site is still in use but I believe the picture is of the EDF1 reactor that was shutdown in 1973. $\endgroup$ Commented Sep 27, 2017 at 17:40
  • $\begingroup$ @user1683793 Thanks. I think only very few nuclear plants were shut down on real safety reasons, the primary effect behind the shutdowns is the mass hysteria around them. $\endgroup$
    – peterh
    Commented Sep 27, 2017 at 18:58
  • $\begingroup$ @peterh, your comment on "mass hysteria" is misplaced. People are aware of the documented history related to the actual, long-lasting impacts of the Hiroshima and Nagasaki bombs, which clearly revealed the consequences of exposure "in the extreme". In terms of "less dramatic", the Three-Mile Island incident just as clearly revealed that such plants are not 100% safe. Safety as regards to nuclear can only be viewed as relative, never absolute. Fast-forward to Chernobyl and then Fukushima, and you have to ask "is any nuclear power plant safe"? $\endgroup$ Commented Nov 2, 2023 at 2:07
  • $\begingroup$ Thank you, @peterh, for your very erudite exposition on the topic. From what you said, I think I can safely conclude that you did not look at my profile. My background is mechanical engineering. I am familiar with the existence of many ways people try to minimize risk and contain exposure to failures. I am not, and have never been, a "green", and I certainly don't have that "religion". On the other hand, I know, just as the first Jurassic Park movie exposed, that man will never fully control nature. Nuclear energy falls under that umbrella. I have nothing more to say. $\endgroup$ Commented Nov 5, 2023 at 1:29

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