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PWR's should not be that damaged by air crashes as they have their spent fuel pools inside the containment dome. Test have been made with fighter jets on rocket sleds. It's worse with BWR's (except Mark III containments) where the spent fuel pools are outside the containment. But all the French plants are PWR's, which make these comments from the ASN somewhat puzzling.  

An airliner is essentially a long thin tube of aluminum, with the only solid part being the jet engines, but even they should not do more than marginal damage to the containment dome.

Peak oil is not an energy crisis. It is a liquid fuel crisis.

by Starvid on Tue Mar 29th, 2011 at 03:37:01 PM EST
[ Parent ]
The containment dome doesn't have to be penetrated to cause damage to the equipment inside.  See wikipedia discussion on spall.  

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre
by ATinNM on Tue Mar 29th, 2011 at 03:57:45 PM EST
[ Parent ]
I'm previously only aware of spalling issues when discussing armored vehicles. :)

But I can't see how spalling would damage the reactor, if we're not talking about huge chunks of concrete falling down into the water, crushing the reactor "top shield", and then continuing down, entering the reactor tank itself and crushing the core. I find that very, very hard to believe.

Peak oil is not an energy crisis. It is a liquid fuel crisis.

by Starvid on Tue Mar 29th, 2011 at 04:07:38 PM EST
[ Parent ]
I'm neither an Mechanical, Materials, or Nuclear Engineer.

All I know is spalling happens on impact.  What spall damage would result from a 747 weighing 377,842 kg, carrying 199,158 liters of aviation fuel, traveling at ~900 km/h would to the equipment & etc. inside the containment dome is outside my competence.  I think it is safe to say, despite my ignorance, the exterior and interior damage to the dome would be greater than caused by a Cessna 207 weighing 1,500 kg, flying at  280 km/h.

But don't quote me!  :-)

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre

by ATinNM on Tue Mar 29th, 2011 at 04:52:39 PM EST
[ Parent ]
The leaked German study on vulnerability to airplane crashes names release of radioactivity due to falling concrete as the smaller risk, and an airplane fuel fire inside the containment as the bigger one. Then you can get to a zirconium fire.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Tue Mar 29th, 2011 at 05:01:20 PM EST
[ Parent ]
I don't see how jet fuel could enter the containment without breaching the containment dome, which I find it hard to believe would happen.

Spent fuel problems in a BWR is another much greater problem in this scenario. As a matter of fact, I remember how I asked about that very thing on a field-trip to the nuclear plant Forsmark when I was like 17. The guide/expert answered that there was no risk to the reactor if a jet-liner would crash in it, but the spent fuel pools were something else. Then he looked a bit troubled.

Peak oil is not an energy crisis. It is a liquid fuel crisis.

by Starvid on Tue Mar 29th, 2011 at 05:17:44 PM EST
[ Parent ]
breaching the containment dome, which I find it hard to believe would happen.

This is not a question of faith...

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Mar 29th, 2011 at 05:21:31 PM EST
[ Parent ]
No, it is not. I would love to see a study done on this issue.

Peak oil is not an energy crisis. It is a liquid fuel crisis.
by Starvid on Tue Mar 29th, 2011 at 05:23:21 PM EST
[ Parent ]
Should I translate relevant parts of the leaked German study I referred to?

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Tue Mar 29th, 2011 at 05:40:09 PM EST
[ Parent ]
The leaked memo is here, however, it is more conclusions than details of the simulations, so I rather do a summary.

  • Two independent institutions did simulations, both on Konvoi-type reactors with 180 cm thick protection. One simulation tested three types of passenger jets (B-747, A-320, A-340-600) with various speeds and directions of impact, no such details for the other.
  • Both simulations showed that the Konvoi-type containment would crack but would not allow kerosene in, but the second simulation made an exception for an impact at the rim of the top and sides. Only impacts on the valve compartment would knock out the cooling system, and the control systems would be knocked out, especially of the emergency control room would be hit.
  • Both research groups said that based on these results, the containment of the plants older than the three of the Konvoi class can be assumed unfit to resist an impact even without detailed studies. (These reactors have no protection hull or concrete hulls of 40 to 120 cm thickness.)

The document makes the explicit conclusion that 'the retrofitting of the older reactor buildings is not possible resp. doesn't make sense from technical resp. economic considerations'. Instead they recommend counter-measures in the airplane cabins, and obstacles in the line of flight (concrete pillars).

Meanwhile, I also found a page on another study, the safety of spent fuel storage rooms. It found that one type, which has 1.2 m thick walls, would resist impact, but that of another type, with 70 or 85 cm thick walls and 55 cm thick roof, would not resist impact, however kerosene would supposedly flow out via channels.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Wed Mar 30th, 2011 at 04:35:35 AM EST
[ Parent ]
Duplicate deleted.
by afew (afew(a in a circle)eurotrib_dot_com) on Tue Mar 29th, 2011 at 04:08:02 PM EST
[ Parent ]
An airliner is essentially a long thin tube of aluminum, with the only solid part

Meh. It's not the solidness, it's the kinetic energy. After the WTC and Pentagon crashes, this should be common knowledge.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Mar 29th, 2011 at 04:52:29 PM EST
[ Parent ]
If the WTC had been 50 metres tall and surrounded by a metre thick wall of reinforced concrete, I believe the result might have been quite different.

Peak oil is not an energy crisis. It is a liquid fuel crisis.
by Starvid on Tue Mar 29th, 2011 at 05:19:55 PM EST
[ Parent ]
So you'd have only have received a hole similar to that in the Pentagon?

Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Tue Mar 29th, 2011 at 05:37:27 PM EST
[ Parent ]
If the Pentagon had been sorrounded by a metre thick wall of reinforced concrete, I believe that outcome would also have been somewhat different.

Peak oil is not an energy crisis. It is a liquid fuel crisis.
by Starvid on Wed Mar 30th, 2011 at 12:59:27 PM EST
[ Parent ]
I don't know about the WC, but in the Pentagon crash, several 14-inch (35.56 cm) concrete columns were destroyed by the impact deep into the building.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Tue Mar 29th, 2011 at 05:39:20 PM EST
[ Parent ]
yeah, but that was by an alien deathray, not an aeroplane.
by njh on Wed Mar 30th, 2011 at 07:29:31 AM EST
[ Parent ]
I get 0.5*400tonne*(900km/hour)^2 = 2.7 tonne tnt

Not tiny, but not huge either.  Fully laden, the fuel tanks contain pretty much exactly 2 kilotonnes tnt, but it's not clear how that energy would couple to a building.

by njh on Wed Mar 30th, 2011 at 07:26:53 AM EST
[ Parent ]

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