10-15KT Bomb vs Times Square

[roo_ster]

My favorite nuke engineer is not handy and I would like some of y'all's opinions on this fellow's post.

Looking at Google maps, the bold-face description does not seem excessive, but I expect that the zone of absolute destruction would also be a function of building construction materials & methods.

I think that the death toll is about right, but that the evacuation of Manhattan for an indefinite amount of time would be as disruptive as the blast.  It brings home that the joke about, "let them nuke NYC/LA/etc" is not so funny, as an evacuated Manhattan would translate to HUGE economic turmoil and the displacement of millions. 


http://corner.nationalreview.com/post/?q=YjNlZjY3NTM5NGY4YjA5NjhmYjZhNDk4ZGE2ODIyMzc=

Time to Ask Tough Questions about Terror    [Michael Anton]

Bret Stephens ends his column yesterday with the following paragraph:

    One day a Pathfinder with tinted windows may park itself in Times Square with something more than propane tanks in the back seat. We may not be able to stop it. But we will live more securely if the driver of that car knows exactly what we intend to do next.

If I may be allowed to parse: One day some terrorist is going to drive a panel truck (it probably won’t be an SUV) into Manhattan or Washington. On the bed of that truck will be a large, cumbersome, relatively unsophisticated (by American or Russian standards) nuclear weapon. It will be far too large to put on a missile or even drop from any but a very large aircraft, which in any event would not be able to penetrate U.S. airspace nor the airspace of any country targeted by various jihadists. The two fissile pits will be made from highly enriched uranium — a far easier nuclear fuel to make that the alternative, plutonium 239. Indeed, that HEU might not even be enriched to 90 percent (the optimum level for weapons-grade fuel), which, as the Iranians are learning, is not so easy to do, even if you master rudimentary enrichment. But no matter, lower grade HEU can work just as well. You just need more of it to reach critical mass, making the bomb rather heavy and large, but if your delivery device is a truck, so what?

The two pieces of sub-critical HEU will slam together after one is fired down an artillery tube at the other. The bomb will yield between 10 and 15 kilotons (about the power of Little Boy, dropped on Hiroshima and based on the same design) and will erase (if detonated in Times Square) everything up to about 50th Street and down below 34th Street, with fires and flying debris reaching at least 72nd and 14th Streets and probably crossing the Hudson to the west and reaching the East River in the other direction. Since the device would be detonated at ground level, fallout would be immense and the extent and dispersal patterns would depend on the prevailing winds that day and for the next 48 hours. Manhattan would be uninhabitable, potentially for years. At least 100,000 people would die, probably many more, and untold more would be injured or suffer radiation poisoning or deadly mutation.

There are a non-trivial number of people in the world who would very much like to do this to us. It won’t be easy, and they may never get the chance. They may also be caught in the act of trying at any of the various stages of the plot. These people are, however, probably not deterrable.

This much the conventional wisdom on terrorism has right. But there are also a handful of states that would like to see this happen, or at least would not object, and may lend a hand in helping it happen, especially if they calculate that their role in the act will appear sufficiently ambiguous to minimize the chance of American retaliation. And then there are the surrounding societies that by turns and to various degrees support, oppose, or look the other way at the terrorist and ancillary activities that go on in their midst every day.

Are these actors also utterly undeterrable? The conventional wisdom says yes. Stephens suggests, maybe not. One thing is certain: As a nation, we haven’t asked. Our foreign policy and security establishments have not explored and debated. The issue is simply one that cannot be spoken of.

Stephens deserves credit for raising it, even in an oblique, terse, fractional way. To discuss these matters is to risk one’s reputation and perhaps livelihood. But the stakes are high enough that reputations will have to be risked. One would hope also that the stakes are high enough that those inclined to pounce on heterodox and — let’s begin to be frank — gruesome-sounding inquiries will perhaps hold their tongues in the interests of intellectual inquiry and national security. (One can hope this while suspecting that the hope is unlikely to be realized.)

Declaratory policy is what nations say about how and when and why they might retaliate in various circumstances. The purpose — and hope — is that by making terrible threats, we can make follow-through on those threats unnecessary by staying the hand of those whose hatred can never be assuaged but whose innate senses of self-preservation, rationality, and (yes) fear can be leveraged in our favor. Conventional wisdom and official policy alike hold that declaratory policy has no relevance or role to play in the fight against terror.

This is an unexamined assumption — a reflex or, better, a recoiling from where the inquiry, not to say the conclusion, must lead. It is understandable that no one wishes to wander into that dark, monster-infested forest — nor, worse, to be seen to do so. But sooner rather than later, someone — several of us — must. Stephens is saying: Let’s get on with it. He’s right.

[Jim147]

I'm no where close to an expert on this but if we just take Times Square as a example, I think a ground detonated nuke would make for canyons of destruction.

What I'm trying to say is that instead of having a huge flat spot at the point of detenation the buildings will direct much of the blast down the streets.

It may not look as bad where the nuke went off but I think it will affect a larger area then he is saying. And then there are the ZOMBIES.

jim

[Jamisjockey]

A big nuke seems unreal to me.  Something that big is going to be damn hard to move, transport, hide, and keep secret.  When a nuke is detonated on US soil, I think it'll be much smaller. 

[lee n. field]

A big nuke seems unreal to me.  Something that big is going to be damn hard to move, transport, hide, and keep secret.  When a nuke is detonated on US soil, I think it'll be much smaller. 

Picture it, piece by piece, brought in and built in somebodies apartment.

[Jim147]

A big nuke seems unreal to me.  Something that big is going to be damn hard to move, transport, hide, and keep secret.  When a nuke is detonated on US soil, I think it'll be much smaller. 

My thought is we will see a dirty bomb before a real nuke.

jim

[cassandra and sara's daddy]

i agree and its not a happy thing . at least i live far enough from dc

[PTK]

A big nuke seems unreal to me.  Something that big is going to be damn hard to move, transport, hide, and keep secret.  When a nuke is detonated on US soil, I think it'll be much smaller. 

The US gov't disagrees with you, very much. <50kT, sure, but still... that's a big damn boom.

[Nitrogen]

Check this site out:

http://www.carloslabs.com/

a 15kt weapon would thermally decimate most of lower manhattan, and the pressure wave would hit Jersey City.
Fallout would make it WELL into Jersey City.

I think it's about right.
15kt is really nothing.  Once you get into the 400kt range, you can decimate whole cities.
it'd take something like a 10MT bomb to get partial metro areas.

To give you an idea, a "suitcase bomb" would be between 1-5kt at most.

EDIT: I say "really nothing" compared to what our bigger firecrackers can do.  A 5kt weapon is more than enough to cause a lot of damage in the right area.

[Nitrogen]

The US gov't disagrees with you, very much. <50kT, sure, but still... that's a big damn boom.

The other thing to realize is the amount of radiological material to make something that big would be easier to find I think.  The "sweet spot" for being hard to find, small size, and big enough boom is probably somewhere south of 15kT.  In my ametuer opinion, its probably around 5kT at most.

[Bogie]

I'm thinking dirty bomb myself... and in pieces, so they can take it to the top of a building, or at least 20-30 stories up...
 

[French G.]

Yet another thread where I had a typed reply and then hit backspace. They might have thought of it, but so far, thank god for dumb criminals.

[kgbsquirrel]

A big nuke seems unreal to me.  Something that big is going to be damn hard to move, transport, hide, and keep secret.  When a nuke is detonated on US soil, I think it'll be much smaller. 

The core for the most simple of spherical nuclear weapons is only 60kg of 80% HEU and is about 7 inches wide sans explosive lens, and still be on par or slightly better than the gun type device used on Hiroshima. Properly assembled you are looking at something approximately the size of a large foot locker.  Far easier to handle and transport that one would like to think.

I second the thought regarding the channeling of the explosive force down the streets, though immediately at ground zero you'll like to see a total pulverization of the buildings directly next to the device, with probably pulverization/incineration of the next tier of buildings. Past that I'd expect to see something along the lines of the support columns of buildings being sheered near the ground level with subsequent toppling. The thermal pulse and shock wave could likely be channeled down the streets causing a concentration and extension of destruction past the distance you would normally see in an open terrain detonation.

The one saving grace, and I use that term loosely, would be if it was a ground detonation, which would be likely with this scenario. True this results in a larger amount of fallout than an air burst but it also would limit the blast some. Ideal altitude for detonation is actually about a mile above ground as it gives you a wider area of effect.


I'm starting to regret paying attention to my NBC training that I had to go through.... 

[Jamisjockey]

I'm not talking about the KT size, but the delivery device.  Even assembling such a large weapon would be tough to do at best.
I'm thinking it would have to be small enough for two people to carry it, and to fit into a van or SUV. 

[PTK]

....which isn't hard to do. Did you even read what he posted?


EDIT: Ok, just did the math with a friend. For a complete, ready-to-go-boom device, we're looking at a two foot sphere, weighing around 197lbs. That'd be for 20Kt, really easy to make, and readily available materials/components. No special skills or tools required, and basically any moron knowing how to make a shaped charge could do it with the correct materials (which, again, aren't hard to get)
 
So, how is a two foot sphere, contained however you'd like, weighing less than 200lbs, hard to carry, hard to fit into a van/SUV, or hard to conceal in any way?


BTW, this is for an implosion type, NOT a gun type. For a gun type, you're 100% correct that it would be big, heavy, hard to move/conceal, etc. (Un)luckily, an implosion type is smaller, more efficient, and still easy as heck to build.

[Waitone]

Don't need a bang.  All the bad guys need is a strong alpha particle emitter and a slew of Geiger counters in the hands of NY's "journalists".  Stir in a generous dollop of 24 hour cable news air time and fold into a few follow on nut cases and you'll kill and terrorize people by the sack full.  The American media is a formidable force multiplier in any terrorist attack.

[PTK]

The American media is a formidable force multiplier in any terrorist attack.

Sadly, you're quite right indeed. :(

[Harold Tuttle]

After 911 they found a bum in DC with a medical scanning nuke pill in a storage unit.
They supposedly have radiation detectors all over the bridges
and they spent weeks slow flying over DC setting up a background radiation map.

There was a home brew atom bomb plan in Omni magazine back in the 70s.
They showed how you could shoot a half a baseball down a pipe from the attic of a 2 story home into the concreted in basement...
Getting the u235 is the hard task. I expect rods of god to fall upon any future 3rd party manufacturing operation.

Any dirty bomb that yields hot particles is gonna put a dramatic crimp on the real estate market

[AJ Dual]

People who've had radioisotope therapy get stopped at the border.

I suspect that post-9/11 NYC has enough neutron detectors in strategic locations that the powers-that-be would know something was up. Then it would be a race to find the actual device before it's detonated.

IMO, the OPFOR would be smarter to do it somewhere like Atlanta or Chicago, despite the obvious desire to hit NYC/D.C. etc.

And unless it was a purloined Russian device, maybe Indian or Pakistani, I would not trust an implosion device to work with a reliability of even < 50%. The issues of explosive lens timing/simultaneity and neutron enhancers/reflectors are complex, to say the least. The Norks have had a couple of "fizzles" already. Which IMO makes what we did with Trinity and Fat Man all the way back in 1945 all the more amazing.

They'd be wise to go with a gun design, or similar.

Don't need a bang.  All the bad guys need is a strong alpha particle emitter and a slew of Geiger counters in the hands of NY's "journalists".  Stir in a generous dollop of 24 hour cable news air time and fold into a few follow on nut cases and you'll kill and terrorize people by the sack full.  The American media is a formidable force multiplier in any terrorist attack.

Generally it's fast Neutrons, and specific spectra of gamma photons they're looking for. Alphas and Betas won't make it through the housings many radiological detectors that DHS has are placed in, let alone trigger them. And understanding just some of the science behind it, they have a very good guess of what it is they're detecting from the MeV of the Neutrons even. To the point they can make an educated guess if it's a Uranium or Plutonium device they're catching wind of.

Even several feet of air is problematic for Alphas. If simple FUD by setting off all the detectors is your plan, I'd say purloined Cobalt 60 from a retired third-world radiotherapy medical device is your best bet there.

....which isn't hard to do. Did you even read what he posted?


EDIT: Ok, just did the math with a friend. For a complete, ready-to-go-boom device, we're looking at a two foot sphere, weighing around 197lbs. That'd be for 20Kt, really easy to make, and readily available materials/components. No special skills or tools required, and basically any moron knowing how to make a shaped charge could do it with the correct materials (which, again, aren't hard to get)
 

Not exactly. There are exotic materials for desired neutron transparency, absorption, and reflectivity that are needed, and machining those into the pit/core is not exactly easy, and is just one of the "black arts" that have been some of the most deeply held secrets of the nuclear bomb industry since the beginning.

And the proper devices and detonators needed to get the required degree of simultaneity, and extremely rapid switching such as the Kytron are controlled-export devices to this day. Although that's not to say China may not sell them at DealExtreme.com for all I know... 

For instance, for days on end, the team at Alamogordo had to use X-rays and dental tools to find every near-microscopic void in the cast explosive lenses and back-fill them to make them absolutely perfect to ensure blast symmetry.

And I'll repeat the point even the NORK's last two tests were "fizzles" unless they were merely testing explosive lenses sans an actual fissile core.  They've got a whole country supporting them, and 55 years of science/technology to make it easier for them.

So while I think a "basement made" gun-device is plausible, any successful implosion device is going to be one that was professionally made and supplied by a third-party state.

[cassandra and sara's daddy]

http://www.guardian.co.uk/world/2003/jun/24/usa.science

[HankB]

Implosion-type devices are more difficult to build than gun-type devices - they require nearly perfect timing to simultaneously detonate very precise shaped charges.

http://en.wikipedia.org/wiki/Fat_man

http://en.wikipedia.org/wiki/Little_boy

Still, it's 1945-level technology. Anyone that can enrich uranium or produce weapons-grade plutonium in 2010 ought to be able to build a bomb.

Here's a thought . . . what if, rather than detonating the bomb in Manhattan, they decided to hit a nuke plant with it? If the primary detonation of the the bomb was sufficient to include a reactor core, it would be a very dirty event. Or what if they packed the truck carrying the bomb with NON-enriched uranium, cobalt, or something else? That would make something bad even worse.  

(If the Iranians did this to us . . . I wonder if Obama would take appropriate action, or insist on a "measured response" by having Eric Holder seek indictments against Iran's mullahs?)

[RoadKingLarry]

I'm not talking about the KT size, but the delivery device.  Even assembling such a large weapon would be tough to do at best.
I'm thinking it would have to be small enough for two people to carry it, and to fit into a van or SUV.  

I'd bet such a thing would easily fit into the back of a Nissan Pathfinder...

(If the Iranians did this to us . . . I wonder if Obama would take appropriate action, or insist on a "measured response" by having Eric Holder seek indictments against Iran's mullahs?)

I've no doubt Obama could find something to apologize for to the Iranians...

[sanglant]

Yet another thread where I had a typed reply and then hit backspace. They might have thought of it, but so far, thank god for dumb criminals.

if firefox is a option, it will save what you have typed. you can hit foward to return if you went back, or open closed tab if you closed the tab.

[roo_ster]

One wonders how difficult it would be to line the cargo area of a Ryder truck (or similar) with lead foil or malleable 1/8" thick slabs and then seal it up to prevent transfer of gases?

Could it be as easy as substituting lead for aluminum in the radiant barrier solution and spraying it on the inside and then doing something similar with foam insulation and vapor barrier?

[AJ Dual]

One wonders how difficult it would be to line the cargo area of a Ryder truck (or similar) with lead foil or malleable 1/8" thick slabs and then seal it up to prevent transfer of gases?

Could it be as easy as substituting lead for aluminum in the radiant barrier solution and spraying it on the inside and then doing something similar with foam insulation and vapor barrier?

It would take a pretty heavy thickness to stop fast neutrons.

Pu 239 releases 5.9Mev neutrons when fissioned naturally/spontaneously. As little as 1mm of lead foil will significantly cut down on the gamma photons which are only in the KeV range because they're (nearly?) massless. But the Neutrons are heavy pigs, and it'll probably take at least 10x or more to seriously attenuate the neutrons.

And that's assuming the Neutrons are all at 5.9 MeV. If there's anything "spicier" in the bomb as a neutron enhancer, or some other factor of it's design that's pumping the Neutrons up to 10+ MeV, then you're talking LOTS of lead shielding. The detectors are VERY sensitive. And can make very good guesses as to what they're "smelling" due to the different MeV's of the particles they're detecting.

Also, that's assuming they've got PURE Pu239, Pu produced in a reactor tends to catch an extra neutron about 1/4 the time and become Pu240 which is a much worse neutron emitter, and generally Pu implosion devices just work with supercritical pits because Pu239 has such well behaved spontaneous decay properties. Bad JuJu to have that 240 in there.

And IMO, (no real experience, one of these deep dark secrets) I think that getting the Pu240 out of the Pu239 is damn hairy. You're trying to do (what? dunno...) gas centrifuge separation on (what? dunno...) Plutonium Hexaflouride with only a weight difference of one neutron? It's hard enough as is with three neutrons separating U235 and the useless U238.

(shrug)

Getting some PhD's together to say "this is how you do it" isn't the hard part in building an implosion device. It's all the engineering that's a PITA. Machining any Beryllium? What about Cadmium? Is it hard, is it easy? Is it pyrophoric, requiring inert atmospheres?

[Harold Tuttle]

A suitcase nuke or suitcase bomb is a very compact and portable nuclear weapon and could have the dimensions of 60 x 40 x 20 centimeters or 24 x 16 x 8 inches. The smallest possible bomb-like object would be a single critical mass of plutonium (or U-233) at maximum density under normal conditions.
The Pu-239 weighs 10.5 kg and is 10.1 cm across. It doesn’t take much more than a single critical mass to cause significant explosions ranging from 10-20 tons. These types of weapons can also be as big as two footlockers.
The warhead of a suitcase nuke or suitcase bomb consists of a tube with two pieces of uranium, which, when rammed together, would cause a blast. Some sort of firing unit and a device that would need to be decoded to cause detonation may be included in the “suitcase.”
Another portable weapon is a “backpack” bomb. The Soviet nuclear backpack system was made in the 1960s for use against NATO targets in time of war and consists of three “coffee can-sized” aluminum canisters in a bag. All three must be connected to make a single unit in order to explode. The detonator is about 6 inches long. It has a 3-to-5 kiloton yield, depending on the efficiency of the explosion. It’s kept powered during storage by a battery line connected to the canisters.
Effects
External radiation occurs when either part of or all of the body is exposed from an external source, such as when a person is standing near the site of where a radiological device such as a suitcase bomb or suitcase nuke is set off and he or she is exposed to radiation, which can be absorbed by the body or can pass completely through it.
Contamination occurs when radioactive materials in the form of solids, liquids or gases are released into the air and contaminate people externally, internally or both. This happens when body parts such as the skin become contaminated and/or if the harmful material gets inside the body via the lungs, gut or wounds.
Incorporation of radioactive material occurs when body cells, tissues and organs such as bone, liver, thyroid or kidney, are contaminated.
Gamma radiation can travel many meters in the air and many centimeters once in human tissue; therefore they represent a major external threat. Dense material is needed as a shield. Beta radiation can travel meters in air and can moderately penetrate human skin, but clothing and some protection can help. Alpha radiation travels a very short distance through the air and can’t penetrate the skin, but can be harmful if inhaled, swallowed or absorbed through open wounds.
Radiation in the first hour after an explosion is about 90 percent, with it going down to about 1 percent of the original level after two days. Radiation only drops to trace levels after 300 hours.
Symptoms
People in the immediate vicinity of a suitcase nuke or suitcase bomb detonation would likely die from the force of the conventional explosion itself. Some survivors of the blast might die of radiation poisoning in the weeks afterward. Those farther away from the explosion might suffer radiation sickness in the days and weeks afterward, but recover. Over time, risks of cancer in the affected area would rise, but perhaps only slightly.
A mix of physical symptoms must be used to judge the seriousness of exposure. Impact of radiation poisoning also changes if the body has experienced burns or physical trauma. In the case of treatable victims, extensive medical treatment may be needed for more than two months after exposure.
Some symptoms may include vomiting, headache, fatigue, weakness, diarrhea, thermal burn-like skin effects, secondary infections, reoccurring bleeding and hair loss.
Treatment
If detection and decontamination occurs soon after exposure, about 95 percent of external radioactive material can be removed by taking off the victim’s clothing and shoes and washing with water. Further decontamination may require the use of bleaches or other mild abrasives.
Treatment of a victim within the first six weeks to two months after exposure is vital and is determined by what types of radioactive isotopes to which the victim was exposed.
Medical personnel will treat victims for hemorrhage and shock. Open wounds are usually irrigated to cleanse them of any radioactive traces. Amputation of limbs may occur if a wound is highly contaminated and functional recovery isn’t likely.
If radioactive material is ingested, treatment is given to reduce absorption and enhance excretion and elimination. It includes stomach pumping or giving the victim laxatives or aluminum antacids, among other things.
If radioactive material has gotten into a victim’s internal organs and tissues, treatment includes giving the patient various blocking and diluting agents, such as potassium iodide, to decrease absorption. Mobilizing agents such as ammonium chloride, diuretics, expectorants and inhalants are given to a patient to force the tissues to release the harmful isotopes. Other treatments involve chelating agents. When ingested, these agents bind with some metals more strongly than others to form a stable complex that, when soluble, are more easily excreted through the kidneys.

http://www.nationalterroralert.com/suitcasenuke/