Radiation Detector Program Delayed

[cal04]

Source: Washington Post

DHS May Have Misled Congress, GAO Audit Finds

A $1.2 billion program to deploy new radiation monitors to screen trucks, cars and cargo containers for signs of nuclear devices has been delayed by questions over whether Department of Homeland Security officials misled Congress about the effectiveness of the detectors.

Homeland Security Secretary Michael Chertoff announced the contracts for monitors with cutting-edge technology a year ago. He said they would improve radiation scans at borders and ports, while sharply reducing the number of false alarms. Congress had allowed the five-year project to move ahead after Homeland Security assured appropriators that the $377,000 machines would detect highly enriched uranium 95 percent of the time.

"What this next generation of detection equipment is going to let us do is make those determinations much more precisely, much more easily and much more quickly," Chertoff said.

But the department's Domestic Nuclear Detection Office did not know whether the detectors would work effectively, according to documents and interviews.

Read more: http://www.washingtonpost.com/wp-dyn/content/article/2007/07/19/AR2007071902615.html?hpid=topnews

[Eagle_Eye]

1. 1.2 BILLION dollars put in the pockets of little george's supporters

bush starts a war to line the pockets of rich contractors.
It does not matter if the radiation detectors work or not, the objective of the bush administration is to transfer taxpayer dollars to his rich contractor friends

[SpiralHawk]

2. "Lying is what we do." - Homeland Republicons

Republicons can go somewhere else in their diapers and have their freaky fascist Homeland, but leave the United States of America to the rest of us who care about honesty, integrity, freedom and justice.

[Solon]

3. What the fuck, Geiger counters dammit, any kid with half a brain and the plans can build one!

What the fuck? Did some big name company "win" a no-bid contract and they ended up shipping paper mache models with fancy dials on the front? How fucking corrupt is this fucking administration? Scratch that, I already know the answer.

[Tesha]

4. You need a lot more than a Geiger Counter to detect the "interesting" stuff.

The "interesting" stuff isn't all that radioactive
on its own and can be "covered" by naturally-
occurring radioactivity that will fool a mere
Geiger counter.

The really useful detectors fire beams of neutrons
into the suspect materials and look to see if
other neutrons (neutrons from the fissioning of
fissile materials) are being produced.

Tesha

[Solon]

5. True, but I really don't think any independent terrorist group would be able to get their hands...

on it. The only sure fire way to prevent detection would be to shield it, but shielding is heavy and expensive, making it hard to easily transport a nuclear device. Terrorists, even Osama Bin Laden, if he was smart, wouldn't even consider trying to get a hold of nuclear weapons, for, to be frank, delivery is a huge, almost insurmountable problem. The best he can do is to try to use a "dirty" bomb, and would use the cheapest, most readily available radioactive material to use with the bomb. Granted, this itself is actually pretty stupid, outside of the immediate bomb blast, you basically increase the cancer probabilities by 10%, big whoopee do, we have a nuclear waste literally ten miles from me, in an inhabited area at that, it probably has a bigger negative affect in that area than any dirty bomb could hope to achieve.

Regardless of the probabilities, the chance is still there, so we should prepare for it, the first line of defense would and should be tried and true technology, like Geiger counters, and use more sophisticated detectors as the second line of defense.

[Tesha]

6. With our success at interdicting drugs...

> Terrorists, even Osama Bin Laden, if he was smart,
> wouldn't even consider trying to get a hold of nuclear
> weapons, for, to be frank, delivery is a huge, almost
> insurmountable problem.

Are you kidding? With our success (:sarcasm:) at
interdicting drugs, do you really think we'd be
all that likely to interdict an incoming nuclear
weapon?

It seems to me that all they'd need to do is to
hide it in a bale of marijuana!

Tesha

[Shipwack]

7. Agree, terrorists don't go for hard complicated plans, but...

The terrorist fight mor ethan one kind of war at a time. A dirty bomb, while not doing as much damage as even some conventional bombs, and not being all that horrible long term, would be a psychological and propaganda victory more than anything else. The sheeple would panic over the concept of the terrorists exploding a nuclear bomb, and would ignore the fact how easy it was to make, or how relatively ineffective it was. The media definitely would ignore these points.

Even the name has sexy news appeal... "... you dirty dirty bomb... you dirty dirty bomb! You've been a baaaaad bomb.!"

Sorry, where was I?

[nealmhughes]

9. Indeed, a sheet of paper will stop an alpha particle, which is the main form of decay for Uranium.

When raw nuclear fuel is handled, those touching the fuel rods wear only white cotton gloves and that is to avoid oil on the fingers and palms from the body to get on the cladding of the rods.
Even a highly fissile material would be masked by a thin sheet of lead on top of the paper, unless they are looking for the neutrons released from fission and then the lead would stop most of it -- neutrons don't hang around very long, ya see. Even high energy gammas from N absorbing neutrons would be shielded by the lead.
It isn't as if there is an open air flatbed truck going around with not a mm of shielding for the DHS to detect. . .
And neutron detectors are in the very core itself of a reactor on right on the periphery! They need a high voltage source to detect and a geiger counter is good only for alpha and beta and gamma. . . and they can be shielded quite easily by mere lead.

[Sirveri]

11. pretty good, a couple minor points though

Most bombs are made from Pu239 since it's a abundant byproduct of LEU which is used in reactors. It can be sifted out and with good technology fashioned into a nuclear bomb. Refining U235 is harder, although building a weapon from such a device is considerably easier. So really it would depend on what type of weapon they're looking for. A Russian black market Plutonium implosion weapon would easily be detected by neutron emission since it likes to undergo spontaneous fission as a decay method quite often. U-235 would be substantially harder since as you mentioned it prefers to alpha decay.

Neutrons are somewhat difficult to shield against, they generally require large ammounts of water or polyethylene (borated). Gammas would be emitted from neutron capture in water and yield a very high energy gamma wave, which would take several inches of lead to shield against. This all assumes a Pu239 weapon. A U235 gun style weapon would be considerably harder to detect. Also along the neutron path, neutrons have a half life of about 30 minutes, at which time they convert to a proton and become hydrogen. So neutrons do indeed hang about for a considerable ammount of time. Also, until they go thermal, they are highly unlikely to be captured by anything, I hear graphite works great as a moderator though, so such a device could be fooled by wrapping it in graphite and then wrapping it in some borated poly to absorb the now thermal neutron, follow that up with 2 inches of lead and you'd likely get near background.

Also about detectors, there are neutron detectors out there. I've used them, they're fairly bulky and annoying.
Gieger counters do NOT detect alpha particles. Alpha particles are so massive that they actually interact with the probe before reaching the sensor itself and thus don't actually register, so you need a special type of scintillation detector to find those bad boys. It actually reminds me of a story from one of my navy nuke freinds, he used to have to do radiation surveys back when they still had nuclear weapons onboard, and he would have to call the weapon handlers and ask them to point the missles a differant direction because he was getting 'shine' through the bulkhead.

[nealmhughes]

12. It has been since 1985 since I even thought about nuclear detectors.

Come to think of it the alphas were larger than the gamma/beta detectors! The NIs we had were "hidden." I have not a whit of what they looked like, only where the electronics were and the joints where they went into the open reactor compartment. All I remember was having to turn the high voltage off when doing a reactor startup when the neutron level got to a certain point.

Actually borated water would be the best shielding to hide a Pu weapon, as it would have less leakage, and lead would be necessary to further shield the high energy gammas that the neutron aborbed Nitrogen would emit, but if I remember correctly from my old BWR days, they decay at a very fast rate, 17 secs. if I recall.

I still remember the formula for the negative thermal coefficient of reactivity, though!

Water on the floor? Call HP. Detector goes off when extiting the reactor building or rad waste? Call HP! Clean shoes with tape, try again, return to safety of control room/maneuvering room was my motto!

[Sirveri]

14. 7.1 sec HL for N-16.

High Volts off we use on our source range detectors because the flux will get way too high and burn them out. We're taking a mod on the plant and finally going digital from analog, hooray for early 1990's technology! The real problem with N16 is that it beta decays with a 8MeV gamma, Co60 is only 5MeV. Then again higher energy particles are further away from the gamma ray window because they're more than likely to undergo pair production. So in theory you would need less lead to shield them out. But the short half life bites you in the butt, because it means you have an incredibly high activity while you have a continuous neutron source available. However a Pu bomb might not show up in source, it might be considered fiducial, it all depends on Curie content of the weapon. But I still think graphite wrapped in borated polyethylene would be better. Light water has a moderation of 1, Heavy has a value of 4, while graphite has a value in the hundreds. Also water may inadvertantly work as a reflector which could cause a premature dirty fizzle detonation.

Maybe I should go to work at a commercial plant, I might be near the end point with my current employer, I have yet to decide.

Our favorite motto is for painting. One coat for dust, two for rust, five for contamination. Might not be far from the truth, another watchstander showed me a 4mr/hr area outside the secondary shield. It's good to see someone on board here who actually has some background in the industry though and isn't scared shitless about anything nuclear.

[donsu]

8. they just don't want those radiation monitors to show up all that

radiation most people don't know is there. here, there, and everywhere.


cancer, child of radiation

[Tesha]

10. Holy shit! Terraists with Fiestaware! PANIC PANIC! (NT)

http://en.wikipedia.org/wiki/Fiesta_%28dinnerware%29

[truthisfreedom]

13. What this all comes down to is: WE NEED LESS HATERS.

So many more people hate the US now than ever before, all as a result of the bush mal-administration. I think we should take the $1.2B in tax dollars and use it to pay for endless lawsuits against this administration that will keep them so tied up they can't take any action for the remainder of their time in office.