Your scenario is such that the "fizzle" would most likely not be a chain reaction of any kind.
Using reactor grade plutonium increases the amount of material you need to acheive critical mass making it less likely to be of suitcase size. The additional problems of heat from the reactor grade plutonium requires a heat management system be incorporated into the device making it even larger and/or more complex.
This from the US Dept of Energy
Quote:The plutonium-240 content even in weapons-grade plutonium is sufficiently large that very rapid assembly is necessary to prevent pre-initiation. Hence the simplest type of nuclear explosive, a "gun type," in which the optimum critical configuration is assembled more slowly than in an "implosion type" device, cannot be made with plutonium but only with highly enriched uranium, in which spontaneous fission is rare.
So it looks like the simple design for a suitcase nuke won't work with plutonium at all.
Source
Intelligence sources speaking on deep background report serious concern over a new Islamic Terrorist threat. The apparent plan is for twenty Terrorists to infiltrate the United States across the Mexican and Canadian borders. Traveling separately the twenty will rendezvous in New York's Times Square at midnight, January 1st, 2006. The Terrorists, each carrying 1 pound of enriched plutonium hidden in their copies of the Koran, will get into an outlaw gypsy cab together. Once the group is gathered there will be enough plutonium for a 10 KT explosion, if triggered. The cab driver will have already concealed the bomb trigger in the trunk, and at midnight will push the button.
The plutonium was obtained secretly from North Korea and Iran over the last year. A talented Pakistani physicist (trained at USC, and employed for many years by the American AEC, designed the system after deciding against a suitcase nuke. The source of the funding for the project has yet to be determined, but it appears to have come from a secret U.S. government fund overseen by the Vice-President.
When asked if the Vice-President had any comment, he replied "I know nothing and I will be in Aspen on a fact-finding tour over the holidays". A review of all registered gypsy cabs in New York has led investigators to focus on Zev Baummitten a recent arrival from Israel. There is no evidence connecting Mr. Baummitten with the Mosad agent Z. Baummitten who is suspected of leaking atomic secrets to Iran.
Spokesmen for the Democratic Party deny any involvement, and promise to open hearings no later than March, 2006. "This may be the smoking gun" declared one conservative Democrat who refused to be identified, probably because his comments were made at the Dust-Bin Saloon in the Bowery around 2 a.m. last evening. The Mayor of New York has reportedly called on FEMA to prepare to evacuate the City before Christmas eve, and the Mayor of New Orleans has offered to shelter all evacuees from New York in the spirit of the season.
Hilarious, Asherman!!! With your permission, I'll be emailing that story to some friends who'll be very appreciative of the humor
parados wrote:Your scenario is such that the "fizzle" would most likely not be a chain reaction of any kind.
Using reactor grade plutonium increases the amount of material you need to acheive critical mass making it less likely to be of suitcase size.
True that you would need more plutonium, but it's a fairly dense metal.
And if the goal is a mere fizzle rather than a traditional nuclear explosion all you need is to have explosive slam two pieces of reactor-grade plutonium together to form a critical mass.
parados wrote:The additional problems of heat from the reactor grade plutonium requires a heat management system be incorporated into the device making it even larger and/or more complex.
I think terrorists could get by with letting it get hot. It could be assembled shortly before use, and would likely be a suicide mission.
parados wrote:This from the US Dept of Energy
Quote:The plutonium-240 content even in weapons-grade plutonium is sufficiently large that very rapid assembly is necessary to prevent pre-initiation. Hence the simplest type of nuclear explosive, a "gun type," in which the optimum critical configuration is assembled more slowly than in an "implosion type" device, cannot be made with plutonium but only with highly enriched uranium, in which spontaneous fission is rare.
So it looks like the simple design for a suitcase nuke won't work with plutonium at all.
Source
What they are saying is that you can't make a "traditional" nuclear explosion that way because it will fizzle.
That is not a problem if someone will be satisfied with a fizzle.
Great to hear from Asherman. It's been a long time.
To me, with my non-technical background--the problem is hypothetical but none the less frightening. It's my impression that EVENTUALLY, and perhaps inevitably, the technology will be available for the nightmare to occur.
The point is that it can't be a suitcase nuke because of all the requirements to transport and make it work. It would require assembly on site which brings more problems into play. (Like finding the right gypsy cab in NYC. )
:wink:
"Fizzle" also includes the times that the device itself explodes and no chain reaction ever occurs which seems the most likely scenario if you tried plutonium in a gun device. The biggest problem seems to be transport without causing major device malfunction from the heat.
Quote:The greater heat evolution (68 watts for half a
bare-sphere critical mass of R-Pu, vs. 11 watts for
half a bare-sphere critical mass of W-Pu) means that
the thick high-explosive that surrounds the plutonium
and any additional metal shells in a simple implosion
weapon will overheat if R-Pu is substituted for W-Pu.
source
It looks like the half sphere would have a surface temp of 150 degrees. Enclose it and you only continue to build the temperature. (The China Syndrome where it overheats and burns through.) Devices built using Reactor grade seem to require insertion not long before detonation and cooling of some kind prior to that point for the material.
parados wrote:The point is that it can't be a suitcase nuke because of all the requirements to transport and make it work. It would require assembly on site which brings more problems into play. (Like finding the right gypsy cab in NYC. )
:wink:
Why can't the terrorists assemble it wherever their base of operations is, then carry it directly to the target?
parados wrote:"Fizzle" also includes the times that the device itself explodes and no chain reaction ever occurs which seems the most likely scenario if you tried plutonium in a gun device.
Once the plutonium becomes supercritical the likelihood falls to zero.
parados wrote:The biggest problem seems to be transport without causing major device malfunction from the heat.
Quote:The greater heat evolution (68 watts for half a
bare-sphere critical mass of R-Pu, vs. 11 watts for
half a bare-sphere critical mass of W-Pu) means that
the thick high-explosive that surrounds the plutonium
and any additional metal shells in a simple implosion
weapon will overheat if R-Pu is substituted for W-Pu.
source
It looks like the half sphere would have a surface temp of 150 degrees. Enclose it and you only continue to build the temperature. (The China Syndrome where it overheats and burns through.)
This is not an implosion system, so the plutonium will not be completely enclosed in explosives.
They could just let the heat radiate through the suitcase for the short time that the weapon was assembled.
By the way, our messages here will probably be Googled and then studied by anyone who seriously wants to build one of these, so it might not be a good idea to make this thread a ready roadmap to solving all the technological problems of building one.
Imagine putting 2- 60 watt light bulbs inside a metal container and then putting that metal container inside a fabric or plastic suitcase. Without airflow that metal container is going to get real hot real fast. How long will the plastic or fabric container last? How long before the metal expands and the device loses its ability to work properly.
The olde ezbake oven used a 40w lightbulb, had airflow and could bake cookies at 300-350 degrees.
oralloy wrote:By the way, our messages here will probably be Googled and then studied by anyone who seriously wants to build one of these, so it might not be a good idea to make this thread a ready roadmap to solving all the technological problems of building one.
I am already getting all my info from google. The dept of energy has most of it out there.
Hey george...
On the issue of this administration's record of abuse of scientific integrity to enhance corporate and voter-base support (you may have read the other links I gave you, but I wouldn't be much surprised if you did not), let's add to your mini-curriculum this piece following...
http://www.nytimes.com/2005/12/18/books/review/18horgan.html?pagewanted=1
@freedom4free,
Dunno who the guy is, but he doesn't know anything about nuclear weapons. Take it from me, someone who was in the US Navy and knows a little bit about nuclear weapons, man-portable nukes exist.
https://en.wikipedia.org/wiki/Davy_Crockett_(nuclear_device)
Can carry one of these as easily as a human child. Wouldn't even need a big proper suitcase, could fit it in a backpack.
Terrorists detonating a nuke is bad. But not the nightmare scenario. Bad as ground level nuclear detonations are, their effects are limited.
The nightmare scenario is a terrorist biological weapon. And that's considerably easier to do than getting a nuke, or making one of your own.
"Oh no, ISIL detonated a nuke? Where? ...Oh a thousand miles away? Well that's sad, but not very scary."
vs
"ISIL released a bio-weapon in a major international airport and the germ had a week-long gestation period and now there's millions of people all over the world bleeding from their eyes?"
