What Would a Nuclear Bomb Do to a Nuclear Power Station?

A short Q&A with the worlds number one nuclear expert and political commentator, Monsieur Bruno Comby of Paris.

Q) What would a 100 kiloton airburst at 2km do to an say, an EPR?

A) Zero, absolutely nothing to the nuclear part protected by the safety containment, but will still blow up most of the roofs of the auxiliary buildings, offices etc

Q) What sort of strike could cause loss of coolant? (thus a meltdown risk)

A) Difficult to answer at first view. The reference scenario that is taken in consideration and resists 100% is the mechanical shock (direct strike) of a small touristic airplane. No problem with these. Direct hit by major military attacks such as an atomic explosion or EMP are not taken in consideration. There could be an effect such as the meltdown. but even if the reactor melts, the radiation is still contained by the concrete containment. The question becomes what type of atomic explosion does it take to crack the concrete containment. I don’t have the answer (nobody does) but I’m reasonably confident that a 100 megaton blast at 1 or 2 km would produce no effect in the containment airtightness. On the contrary for a blast right on target, I don’t think it would resist. The limit is somewhere in the middle (I’d say around 100m if I had to bet but it’s not worth more than my personal bet ?). A lateral explosion (on the side) at a given distance would probably do significantly more damage to the containment than a vertical explosion at the same distance but in the air vertically above the reactor.

When I asked this same question to my professor in nuclear safety André Gauvenet in 1983-4 (he’s the father of nuclear safety in France) his answer was that you can not design anything (including a nuclear reactor) that withstands everything (including the direct strike of a nuclear blast). In case this happens yes the reactor could melt and the radiation could escape into the environment leading to a major radiation leak into the environment. But even then the direct effect of the blast widely surpasses the radiation released in the environment. The long term effects of the radiation leaks would be very small (if any) compared to the effects of the blast itself and also very small to the consequences of depriving a million consumers of their electricity supply. Therefore in this (unfortunate) event the radioactive consequences are negligible compared to other consequences. If you explode 58 tactical Kinjal nuclear warheads (the Russians have or can have over a thousand in stock) on  the 58 French reactors, not only France but a large part of Europe (in fact probably all continental Europe) would be in the dark for a long time, presumably provoking more chaos and deaths than the explosions (or radiation release).

Then best protection against this would be to have extra electrical capacity (more NPPs than we do have) and or urgency scenarios and survival plans at national or regional levels on how to restart the grid nationally or locally (by regions). There are such plans to a limited extent but I don’t think they could apply (in fact I’m sure they’d be useless) in the 58 kinjal or ICBM scenario. For private persons like you and me, the survival plan (only applicable by a very small number of high competence smart individuals who previously planned what todo and minimal equipment and or would have access to a vehicle enabling them to relocate elsewhere) goes through fleeing (for exemple for my brother flying away with his small private airplane flying at low altitude to avoid radar detection) or steel a sailing boat in a port like La Rochelle and navigate it to the US 🇺🇸 or South America (if they let you in…). My ecohouse in Houilles with overcapacity of Pv Solar and my electric car’s battery (64kWh) can power my house as a small independent grid (off-grid electrical system) but it implies reducing electricity use drastically, which is possible in my case because I can heat the home using wood pellets (in stock) and stop taking hot showers (I take cold showers already most of the time).

Q) What's your view on a nuclear winter?

A) In Hiroshima you could walk through the city one hour after the blast. I know personally 2 persons that did so and are still alive TODAY (and members of EFN).  It’s the blast that kills, not the fallout (or marginally, as for any bomb..,). Total number of Hiroshima deaths : about 100 000. Total number of delayed Hiroshima-caused cancers (cancer over mortality) : about 1000 casualties (only 1% of the short term deaths). The average loss of life expectancy amongst the 200 000 Hiroshima survivors is only 2 months.

A total of 17 448 solid cancer incident cases were identified in a subcohort of more than 100 000 LSS subjects, and of those, 853, that is 6% of the total number of cancers in that population, were estimated to be attributable to radiation. (Most of them are ‘natural’ cancers caused by other causes than the atomic explosion)

Being a Hiroshima survivor is therefore a much smaller cancer risk than smoking 5 cigarettes a day or eating smoked salmon and barbecued meat.

No health effects on the 2nd generation.

In utero effects were only for the children of women who were exposed to more than 0.3 Gy AND who were pregnant between 8 and 25 weeks after conception at the moment of the explosion.