Every time I see or hear the media talking about “dirty bombs” my teeth grate. Dirty bombs are nuclear weapons that are either too inefficient to “burn” most of their fissionables in the explosion or else are built intentionally to spread fallout. The media almost always means what is now being called a radiological weapon, something like a terrorist’s standard anti-personnel bomb, but packed with bits of radioactives lifted from medical equipment, old watches or what have you, instead of rusty nuts, bolts and nails.
Any idiot can build one, but they will probably fail to get more than local dispersal. Bad enough in fact; but by the time the SafetyNuts are done you’d have an entire city evacuated for years over the risk of a handful of extra cancers per year. So this is more mass disruption than mass destruction unless the enemy acquire some really nasty radionucleotides and manage a good dispersal within the desired target footprint.
The first type of real “dirty bomb” is what we will almost certainly get from the enemy. It is dirty because they don’t know how to make their fissionables fission before the plasma blows itself apart. When the fission process occurs there is a chain reaction in which a neutron splits one nuclei, which releases at least one more neutron and on average “a bit” that in turn cause another one or two atoms to do the same. This exponential growth happens so quickly it has no meaning on a human scale.
But on the bomb level it does. Each atom releases a great deal of energy; that radiated energy turns the fissionables and the bomb casing into a plasma racing outwards at an enormous speed… which is still slow relative to the neutron cascade.
If the cascade happens fast enough, virtually all of the Uranium 235 or Plutonium fissions and releases energy before the wisp of plasma blows the ghost of the bomb matter outwards. If the cascade is a bit slow the “flame” is extinquished and the cascade stopped because the remaining fissionables are too far apart to have much chance of a neutron hit.
Those unfissioned materials become a nasty bit of the fallout. It is highly unlikely that an “amateur” bomb will get things right the first time, so one expects 5% or less of the material will “burn”. The other 95% gets dispersed in the mushroom cloud. This is the scenario all of us “in the know” fear: a couple kiloton fizzle with a lot of very hot debris and a deadly cloud drifting down wind.
The second type of dirty bomb is even uglier. If you re-read your ’50’s literature, you’ll run across the “Cobalt Bomb”. This is a thermonuclear weapon packed with Cobalt or other materials that will generate nasty and long lived fallout. The Doomsday bombs of yore.
To my knowledge, no one ever built one. It’s not a terrorist likelihood as H-Bombs are out of range of the technology of anyone but a major state at present… without help that is.
A third type, which falls between the cracks of the definition, is the Neutron Bomb. This is an extraordinarily “clean” bomb with very low yield. It causes limited blast damage but it gives off an extremely intense pulse of neutrons. These kill everything (except roaches and Radiodurans bacteria) in a wide radius. The buildings are untouched and the people are dead.
These were tested but not deployed1. It is doubtful anyone could build one without extensive experience or testing.
Let’s pray none of us ever learn about these things first hand.
1= A clarification for those who want precision: a large number were built, but after a big political battle over deployment in the Reagan years, they were put into storage. They were perhaps disassembled during Bush Sr’s Presidency. I do not know if any of these tactical “Enhanced Radiation Weapons” remain in the US inventory.
It is a shame that neutron bombs were not deployed. Whatever will we use if an airborne ebola variant starts wiping us all out?
I can’t remember; why are roaches so tolerant of raidation that kills other organisms?
I can’t remember; why are roaches so tolerant of raidation that kills other organisms?
Will
Because cockroaches aren’t taken in by Bush and Blair’s warmongering. They know that this war is all about OIL!!
Will: my guess is that there is no actual empirical evidence supporting the ‘advantage’ cockroaches have over other organisms when it comes to surviving ‘zoomie flux’ from nuclear weapons, and that the idea of only cockroaches surviving a thermonuclear holocaust comes from how ubiquitous the little pests are in spite of our determined attempts to rid ourselves of them.
Neutron bombs aren’t exactly the solution to the problem of some biobug, either. Neutron bombs were the solution to the problem of being outnumbered 10 to 1 in armor the day the Screaming Commie Hordes rushed through the Fulda Gap. The idea was that you could produce a casualty inducing dose of radiation capable of killing or incapacitating the crew of a T-72 at a distance where the tank itself could easily survive the blast effects of a battlefield nuke. For a roughly 1 to 3 kiloton ‘enhanced radiation weapon’ the effective radiation killing radius for those within the shelter of a T-72 tank was about 600 meters, and for infantry with only foxholes as cover, about 1300 meters. Furthermore, the tank itself was ‘hot’ enough to kill any replacement crews that attempted to man it within about 24 hours of the exposure as the very shortlived radionuclides produced by neutron capture in the tank’s hull and armor decayed away.
Neutron bombs are like any low-yield device, extremely ‘dirty’ in the sense that Dale discusses. Furthermore, even the most modern W-87 and W-88 thermonuclear weapons of today are extremely dirty themselves, producing at least half (and usually more) of their yield from fission rather than ‘clean’ fusion. To make a clean bomb, you need to get up into the multi-megaton range, where most of the yield is from fusion.
The ‘salted’ weapons Dale speaks of could have their casings made of different materials depending on how long you wanted to deny an area to your enemy. Gold is one of the most deadly if I remember correctly, but also the most short-lived of the options explored (a few days), while Cobalt produces effective (but much lower) radioactivity levels for upwards of 30 years. As far as the FAS knows, the U.S. got out of the enhanced radiation and ‘salted’ radiation weapons biz a long time ago. Indeed, the U.S. has not manufactured a nuclear weapon since the FBI shut down the Rocky Flats plant in 1989.
It wasn’t the virus I was proposing to be killed by the neutron weapon, but the millions of fleeing refugees. Very interesting about the salting though.
Although I was being a bit facetious about roaches, I actually have read that they are extraordinarily radiation resistant, that part of their hardiness is due to an ability to handle large amounts of DNA and cell damage. I don’t have a reference at hand on that so I won’t stand by it as gospel.
The other organism I mentioned, really IS radiation tolerant. Deinococcus Radiodurans has also been called “Conan the Bacterium”. They’ll grow in the pool of a nuclear reactor. No one has a good explanation why it evolved so much redundancy in its’ DNA it can survive radiation doses 3000 times a fatal human dose.
A few others posit it as having evolved in a high radiation space environment or transited via spalled meteoroid from Mars; it’s been suggested we might find it common to both planets because it could actually survive the transit in an encysted form. I have serious doubts about this idea, but it’s a good story!
A note on the neutron bomb: they are, relatively speaking, a very clean tactical nuke. This was one of the reasons they were considered for use in the Fulda.
The weapon leaves off the Uranium jacket which would ordinarily absorb the burst of neutrons when the H bomb goes off; most fusion bombs are really fission-fusion-fission bombs. The neutron bomb leaves off the last step; instead of absorbing and utilizing the last burst of high energy neutrons, they are allowed to pass unhindered from the bomb casing.
One item I have heard again and again, which sound like nonsense (except for some of the sources it has come from) is the “Red Mercury” thing. If anyone can clarify, I’d be much obliged. If you feel the information is sensitive even if not classified, please do it by direct email.
I will admit to censoring my own limited knowledge in this area if the bit of information might be of use to the bad guys. At the very least, I’d prefer to make them work and find it elsewhere!
We live in times when discretion is a matter of life and death.
The neutron bomb was not developed originally for killing Russian tank armies in the Fulda Gap.
The weapon design was originally developed for the American Sprint/Spartin ABM system of the 1960s.
Neutron bombs cause near by fission/fusion/fission bombs to cook off sub-critically from their non-specialized and unfocused neutron bombardment.
The adaptation of the neutron bomb to the tactical nuclear role was a spin off of the 1960’s ABM program.