Can a nuke power plant just blow up?

alancj

Ok, I was watching the movie "Resident Evil: The Apocalypse" the other day. The big evil "Umbrella Corporation" nukes a city to kill the T virus (which is what makes the people turn into zombies ) The cover up for the city getting vaporized is too just say that the local nuclear power plant had a meltdown. I laughed because I don't even think it’s possible for a power plant to just detonate like that. Don't you need highly specific conditions in order to get that kind of a nuclear explosion; something that purposely cannot be met in a nuclear reactor?

-Alan

Grogs

It took a lot of smart people many years to make the first nuclear bombs. It's not something that just happens. Probably the worst-case scenario for a reactor would be a steam-explosion, like Chernobyl. It was enough to blow chunks of the reactor core through the roof of the reactor building. Unlike Chernobyl, all commercial reactors in the US have a large steel-reinforced concrete containment building around the reactor core meant to contain such an explosion, so even that type of scenario is very unlikely.

Pengwuino

I think he meant the real whole nuclear explosion type deal which is impossible. You'd need to introduce a tremendous number of neutrons very very quickly to create an explosion I believe.

alancj

Exactly what I thought...

Astronuc

One could have a prompt critical event, but not like a nuclear warhead. The critical mass in a warhead is nearly pure fissile material and then it is compressed (density increased above normal).

Likely in a nuclear reactor, the prompt event could initiate a pressure pulse which, if strong enough, could cause piping to rupture, or perhaps the pressure vessel to rupture, but then the coolant (assuming water) would flash to steam and one would have a thermal/steam explosion, not a nuclear explosion.

However, introducing sufficient reactivity, by say removing all control rods rapidly is essentially physically impossible.

Wailing Fungus

It is impossible to have a nuclear explosion.

The uranium in nuclear reactors a mixture of U235 and U238, where U235 is only a small percentage, in order to control the reaction.

Facial

You can have a steam explosion.

But a nuclear one? No. The uranium used in reactors is not enriched enough.

alancj

Well, I guess I shouldn't expect too much from a movie like that. I hate plot holes though; and I think that that movie had some to spare...

PerennialII

........ perhaps they wanted to explain the casualties and not the event itself, it's not like people are lining up to see the results anyways .

alancj

No, it was supposed to cover up the nuclear bomb that they drooped on the city. Which is basically what the characters said in the movie, "they’ll nuke Raccoon City with a 5 kiloton bomb and say it was a meltdown at the nuclear power plant."

Pretty freaking dumb…

-Alan

Pengwuino

Yah, no one except 99% of hte general public would believe that crap.

On a related note... some science show (on a reputable channel!) was talking about fusion experiments such as ITER. They were saying that there was a possibility that a fusion test reactor like ITER or the NIF could blow up when started in a small thermonuclear explosion. They can't be using that much fuel could they???

Morbius

Pengwuino,

With respect to NIF - that sounds like the same fear mongering that the local anti-nuclear
group "Tri-Valley CARES" has been spreading.

For example, LLNL recently enhanced its security by adding Dillon Aero M134 Gatling
guns to the Lab Protective Force's arsenal of weapons:

http://www.llnl.gov/pao/com/2006/spr...cover_llnl.pdf

The M134 fires depleted uranium rounds. The anti-nukes leafeted the houses near
the Lab, including mine; stating that if they shoot those guns then my house will be
radioactive for 1,000 years [ where they got that number, I don't know - it has
nothing to do with the 4.5 Billion year half-life of the U-238 in depleted uranium] and
that my house value is now zero. I won't be able to sell my house.

The anti-nukes are so self-righteous that they believe they can tell any type of lie
they want in order to further their cause.

Dr. Gregory Greenman
Physicist

Grogs

A lot of those folks don't do big numbers. I guess anything over 1000 is all the same to them. Too bad the ones protesting Yucca Mountain can handle the large numbers better.

One of the saddest 'facts' I ever saw on one of those 'DU is destroying the world' type webpages was this: "IN A SINGLE GRAM OF URANIUM-238, THERE ARE MORE THAN 12,000 RADIOACTIVE DECAYS PER SECOND!!!!!!!!!" (not sure about the number of exclamation points.) It was sad because the number is correct, and the person who sat down and computed the specific activity surely knew 12,400 decays per second is miniscule. A gram of Technetium-99m, which is regularly injected into people for diagnostic tests, has a specific activity of ~2x10¹⁷ decays per second. They just chose to portray the facts in a way that would scare uneducated people.

Morbius

Grogs,

Exactly!! Nuclear technology is not something that is taught as part of the "general
education" one gets in K-12 schooling. Since people don't know anything about the
technology - it is easy to scare them by telling them it does something it doesn't -
like blow up.

Dr. Gregory Greenman
Physicist

Vincent Vega

In the movie "K-19: The Widowmaker" a Russian nuclear submarine reactor malfunctions and (in the movie) the crew was worried about a minor explosion triggering warheads aboard. I was always under the impression for the warheads to work they must go through specific steps.( like a gun-triggered fission bomb for example)

NateTG

The hard part is getting the fissible material. The gun-barrel designs can be quite simple - they can be triggered by a single explosive charge. (Implosion designs tend to be more complicated.)

Generally, nuclear plants are designed to fail in a less catastrophic fashion.

Morbius

Vincent,

Yes - at least the USA's weapons, and I assume the Soviet weapons, have "locks" on
them. Some are known as PALs - "Permissive Action Links".

The weapons are locked so they can't be detonated in an accident, and a rogue
military officer can't launch a nuke without orders. For example, on USA Trident subs
the "Captain's missile key" is not in the possession of the boat's skipper. It is locked
in a safe. Nobody on board has the combo to the safe. The combo to the safe is
received as part of the order to launch. For more on this see the book "Big Red":

http://www.amazon.com/gp/product/006...lance&n=283155

Dr. Gregory Greenman
Physicist