# Which would be worse? 200km from total Fukushima meltdown, or 200km from Hiroshima/Nagasaki A-bombs? **URL:** \ **Category:** Factual Questions\ **Created:** [March 16, 2011, 8:39am UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892 "2011-03-16T08:39:22Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [March 16, 2011, 8:39am UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/1 "2011-03-16T08:39:22Z")
I think I’ve seen news stories citing the distance from Fukushima to Tokyo as something like 200+ kilometers. In case of a total worst case Chernobyl-plus sized disaster, I’ve been wondering how badly Tokyo could be affected – and that got me thinking, would it be worse than a full blown nuclear detonation, like Hiroshima or Nagasaki? I guess assuming the winds were just right. ---
**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\ **Post date:** [March 16, 2011, 10:50am UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/2 "2011-03-16T10:50:47Z")
A Chernobyl-type incident is simply not possible. so it is a moot point. However, by all accounts you would have a greater risk being downwind of Chernobyl. The Japanese nuclear bombs were air-bursts and wouldn’t have carried a fallout and radiation risk beyond the immediate area. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [March 16, 2011, 1:11pm UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/3 "2011-03-16T13:11:37Z")
Essentially, unless you were downwind in exactly the right spot, being 200 km from a 20 kiloton airburst would be something horrible that happened a long way off, with no direct effects at all. Even if you were downwind, the fallout from such an airburst would be relatively light- you might have an increased cancer risk in your lifetime or something along those lines, but full-bore radiation sickness would be very doubtful, if not impossible. [http://www.springerimages.com/Images/RSS/5-10.1186\_1476-072X-6-5-16](http://www.springerimages.com/Images/RSS/5-10.1186_1476-072X-6-5-16) (that’s a surface burst, which has MUCH more fallout than an airburst, and it still peters out at about 50 km) Some sort of full-tilt meltdown _with_ catastrophic containment failure and the nuclear material itself catching fire (what happened at Chernobyl more or less), is a lot worse to be 200 km from. ---
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [March 16, 2011, 1:24pm UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/4 "2011-03-16T13:24:10Z")
Kind of as I suspected. I wonder if anyone will suggest nuking Fukushima as some were about the BP oil spill… ---
**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\ **Post date:** [March 16, 2011, 1:56pm UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/5 "2011-03-16T13:56:02Z")
> [@Koxinga](#): > > Kind of as I suspected. I wonder if anyone will suggest nuking Fukushima as some were about the BP oil spill… There are certain people that find the allure of cataclysmic weaponry very difficult to resist. I fear them far more than a grumbling nuclear power plant ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [February 27, 2012, 8:10pm UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/6 "2012-02-27T20:10:43Z")
New FOI docs prove that Tokyo and points south received alarming amounts of radiation from the leaking reactor. And the US knew this, on March 13th 2011 ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [February 27, 2012, 8:18pm UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/7 "2012-02-27T20:18:43Z")
yes, the main question is “which way is the wind blowing”? And, of course, are you downriver/downslope from these events? (Or prevailing ocean currents) The events themselves are not that dangerous at that distance or even more than a dozen kilometers. What may be most risky is long-term exposure to the fallout/byproducts. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [February 27, 2012, 8:28pm UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/8 "2012-02-27T20:28:06Z")
> [@FXMastermind](#): > > New FOI docs prove that Tokyo and points south received alarming amounts of radiation from the leaking reactor. > > And the US knew this, on March 13th 2011 Links? ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [February 27, 2012, 8:36pm UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/9 "2012-02-27T20:36:09Z")
Probably should be an entire topic. Sadly, I can’t start one about Fukushima, per Mod directive. Hell, I will get a warning for saying that, ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [February 28, 2012, 3:34am UTC](https://boards.straightdope.com/t/which-would-be-worse-200km-from-total-fukushima-meltdown-or-200km-from-hiroshima-nagasaki-a-bombs/574892/10 "2012-02-28T03:34:44Z")
> [@Koxinga](#): > > I think I’ve seen news stories citing the distance from Fukushima to Tokyo as something like 200+ kilometers. In case of a total worst case Chernobyl-plus sized disaster, I’ve been wondering how badly Tokyo could be affected – and that got me thinking, would it be worse than a full blown nuclear detonation, like Hiroshima or Nagasaki? I guess assuming the winds were just right. Here seems to be an answer. [http://www3.nhk.or.jp/daily/english/20120227\_29.html](http://www3.nhk.or.jp/daily/english/20120227_29.html) But even the worst case scenarios they were imagining, they are small compared to what could actually have happened. (and still can, no kidding, it’s not like it’s over) > [@](#): > > The report looked at how the crisis could escalate - including explosions in the reactors, complete meltdowns and the structural failure of cooling pools used for spent nuclear fuel. > > It said that each contingency was possible at the time it was written, and that it would force workers to flee the vicinity and the situation at the plant would then deteriorate unmitigated. > > In that case, evacuation orders would have had to be issued for residents within a 105-mile radius of the plant, and ‘voluntary’ evacuation for everyone living with 155 miles. > > That area would have included Tokyo and its suburbs, with a population of 35 million people, and other major cities including Sendai and Fukushima. > **[Japanese government hid worst-case scenario on Fukushima disaster and fact 40...](https://www.dailymail.co.uk/news/article-2092139/Japanese-government-hid-worst-case-scenario-Fukushima-disaster-fact-40-MILLION-people-evacuate.html)** > > A 15-page internal document, kept secret over fears of widespread panic, casts doubt on whether the Japanese government was sufficiently prepared to cope with an evacuation on an unprecedented scale. What?? > [@](#): > > But if the core does melt, that insult will probably not be sustained and the containment vessel will fail. All this, if it were to occur, would take a matter of days. > **[Nuclear Experts Explain Worst-Case Scenario at Fukushima Power Plant](https://www.scientificamerican.com/article/fukushima-core/)** > > The type of accident occurring now in Japan derives from a loss of off-site AC power and then a subsequent failure of emergency power on-site. Engineers there are racing to restore AC power to prevent a core meltdown > [@](#): > > Economy minister Yukio Edano said that in a worst-case scenario, if the fuel rods continued to be exposed to the air, large doses of radioactive materials would be released and would prevent workers from entering the reactor buildings. > > Edano said he feared that problems could also occur in another nuclear plant in Fukushima, and that Tokyo might have to be evacuated. > > He added that the cabinet members were told of this scenario. Edano was the chief cabinet secretary at the time and served as the government’s spokesperson. > > The government chose not to make the scenario public. [http://www3.nhk.or.jp/daily/english/20120227\_29.html](http://www3.nhk.or.jp/daily/english/20120227_29.html) But, none of those actually describe the worst case scenario, which would be so very much worse.