Weapons grade uranium

[rivan]

So, with Iran heading back toward processes that could produce weapons grade uranium, I've got some questions about the whole thing.

Their contention - I believe - is that their research is only headed toward power plants. Is the material used in a power plant similarly refined as that used in warheads? By that, is the material refined to a similar extent, or by a similar/the same process or equipment?

Is there enough difference between the two to allow safely say, power plant development and operation, without the worry that some could be 'misplaced' and end up in a warhead? The media and politics around the situation imply there's no such safe ground, but I think we all know how many facts can be ignored when politician sare involved.

 

[Mark R]

The materials are different. Weapons grade material is very highly 'enriched'.

Natural uranium consists of 2 isotopes - U235 (which can undergo nuclear fission in reactors or bombs) and U238 which doesn't (easily). U235 accounts for 0.7% and U238 for 99.3%.

Most reactors require 'enriched' uranium where the U235 is concentrated - usually to around 2-5 % for a power reactor (but some smaller research reactors may need more - perhaps 20%). A bomb requires about 90% or more.

Iran previously had an agreement with Russia to buy pre-enriched uranium. But has, despite this, decided to develop their own enrichment technology.

Any enrichment technology can produce any degree of enrichment required - it's just a matter of making some minor adjustments. Reduce the flow rate or simply recycle the uranium a few times through the equipment and you get a better enrichment.

This is the big concern - once you have uranium enrichment equipment it's quite simple to switch to weapons production instead of reactor fuel production. During WWII the older technology at the time was inefficient and expensive - so acquiring enough equipment to build a bomb was a huge issue. However, modern high performance centrifuge technology that it appears that Iran is researching - is a different story (and even a small plant could do the job).

There are ways that you could check on what is being produced - inspectors could examine the logs for all the equipment and settings, inspect the records of incoming natural uranium and outgoing products, or take samples from the equipment to check that the level of enrichment is appropriate. All this is fine, as long as the inspectors can do their work - if the inspectors get thrown out, then there's no way to be sure that weapons grade material isn't being produced.

a power reactor will use 10 tonnes of (low enriched material each year) and a bomb only needs about 100 kg of high enriched material. If your enrichment plant is capable of feeding a couple of reactors, then there could easily be enough spare capacity to slip out a bomb every year or 2.

 

[Vegitto]

So, with Iran heading back toward processes that could produce weapons grade uranium, I've got some questions about the whole thing.

Okay.

Their contention - I believe - is that their research is only headed toward power plants. Is the material used in a power plant similarly refined as that used in warheads?

No. I believe the material used in powerplants is slightly less radioactive, but more refined (correct me if I'm wrong, please). The waste from the activities in a nuclear powerplant, however, could be used to 'spice up' bullets, so that if they are shot, the person shot with that bullet will die either of the bullet or of the cancer afterwards. Also, they make sure that that way, the land that was used to fight the battle on will never, ever be fertile again (at least, not for the coming ~1500 years or so ).

By that, is the material refined to a similar extent, or by a similar/the same process or equipment?

Powerplant-grade material is more refined, I believe, and I think weapons-grade and powerplant-grade are formed by one and the same process.

Is there enough difference between the two to allow safely say, power plant development and operation, without the worry that some could be 'misplaced' and end up in a warhead?

Yes, it is easily checkable. However, last time I checked, the UN wasn't allowed to research any of the activities and materials used in Iran's powerplants. All they got was a regular visitors tour.

The media and politics around the situation imply there's no such safe ground, but I think we all know how many facts can be ignored when politician sare involved.

Well, considering the ultra-conservative president Iran has now, and the inmensely large percentage of the people of Iran supporting his actions, nuclear war against Israel or the USA might not be so far away. This, combined with the pact Iran and Syria have made, makes for an explosive combination. Iran + any-grade uranium/plutonium = No-go.

I really don't trust that Ahamedinejahd, or however you spell that name.. He's too "Allah Hakbar!"-ish for my taste.

 

[ribbon13]

I feel so jipped. Iran has a civil engineer for a president, and we have an ex-coke fiend.

 

[Vegitto]

I thought radical islam opposed all technology?

 

[rivan]

MarkR, thanks for the informative post - lots I didn't know in there. Your answer is exactly the reason I brought this here.

Vegitto, while I may agree somewhat with some of your opinions, this isn't the correct forum to voice them, and don't really relate to the original post.

 

[Marthisdil]

But radical Islam is happy to blow you up in the most gruesome ways possible.

 

[BrownTown]

No. I believe the material used in powerplants is slightly less radioactive, but more refined (correct me if I'm wrong, please). The waste from the activities in a nuclear powerplant, however, could be used to 'spice up' bullets, so that if they are shot, the person shot with that bullet will die either of the bullet or of the cancer afterwards. Also, they make sure that that way, the land that was used to fight the battle on will never, ever be fertile again (at least, not for the coming ~1500 years or so ).

1. Spice up bullets?, wtf are you talkingn about. Uranium produces very little radiatios, and even bomb grade uranium is relatively safe. Maybe you are refering to depleted uranium?, that is the almost prue U238 produced as a byproduct of enrichment, and produces very little radiation. It is used in tank shells and other applications because it is very dense and therefor can project energy better than other metals. (I beleive its something like 30% more destructive than tungsten which used to be used in tank projectiles). However, it should be noted that its use in weapons is only because of its high denisty andd has nothing to so with radioactivity.

2. It depends what you mean by "more refined". Obviously bomb grade uranium undergoes much more intensive enriching since it has to be a much larger percent U235 (it doesn't actually have to be 90%, i think somewhere around 20% is good enough to make a bomb, very high enrichment just helps it to be more powerfully for its weight and it not required). However, it is true that the uranum used in power plants also has to be free of alot of impurities which could cause problems like corrosion and cracing in the feul rods. In a bomb it doesnt really matter about impurities as much because the things gonna be blown to hell anyways.

 

[oldman420]

this explains it all pretty well.
http://en.wikipedia.org/wiki/Critical_mass

 

[Vegitto]

Originally posted by: rivan
MarkR, thanks for the informative post - lots I didn't know in there. Your answer is exactly the reason I brought this here.

Vegitto, while I may agree somewhat with some of your opinions, this isn't the correct forum to voice them, and don't really relate to the original post.

My little bit of text didn't have any oppinions, in them, just facts. It is true that radical islam opposes technology, and it is true that UN inspector's couldn't inspect the stuff they were supposed to inspect.

 

[IronWing]

Originally posted by: Mark R
....
Most reactors require 'enriched' uranium where the U235 is concentrated - usually to around 2-5 % for a power reactor (but some smaller research reactors may need more - perhaps 20%). A bomb requires about 90% or more.
....
a power reactor will use 10 tonnes of (low enriched material each year) and a bomb only needs about 100 kg of high enriched material. If your enrichment plant is capable of feeding a couple of reactors, then there could easily be enough spare capacity to slip out a bomb every year or 2.

A couple points: A bomb can be made with much lower enrichment than 90%. The U.S. tends to use 87-93% enrichment in bombs because they can be made smaller.

As you say, enriching to high grades can be done in a plant designed for low grade fuel production but it isn't easy and is very time consuming and, in a small enrichment plant, it can't be done at the same time as low grade fuel is being produced. In a small plant the enrichment cascade needs to be dedicated to high or low grades.

Cogema has lots of good info on their site: www.cogema.com

 

[da loser]

how big is such a facility and how many people are involved? what about material and energy usage? there is always talk about having hidden underground facilities, but i wonder if this is really plausible. also does iran have it's own uranium ore?

 

[BrownTown]

these plants are frikin huge, when the US first build one in WWII it was the biggest building in the world at the time, obviously things ahve gotten better since then, but still were taling about big buildings that require huge amounts of power. They cost billions to build, and to put it underround would probably cost tens of billions. Of course if you are a leader of a country like Iran then tens of billions of dollars aren't that hard to come by, but it is still very hard to keep secret even if you have the money to build it. Also, i *think* that there are spy planes designed with radiation detectors to detect the small amounts of radiation emmited from such plants. Basicaly its really hard, but i'm sure its possible if you have the money Iran does from Oil.

 

[Mark R]

How big the facility needs to be depends on the amount of enrichment that's needed, and the technology used to enrich it.

The technology used for the first US bomb was calutrons - banks hundreds of vacuum chambers, each something like 20 feet along each side and equipped with huge electromagnets and heaters - each bank capable of a couple of grams of U235 a day.

That technology was soon made obsolete by the discovery of diffusion enrichment. Although cheaper and simpler than the calutrons, it was highly inefficient and required enormous plants (essntially, the uranium had to go through thousands of stages for reactor fuel - tens of thousands for weapons). Cogema have a plant in France for producing reactor fuel - It needs a dedicated connection to a nearby 4 reactor power plant for energy!

The sheer size and energy requirements of the previous 2 techniques is likely to make their construction very obvious.

The modern method is centrifuges. These are about 100x as efficient as diffusion, and can be made much smaller - and are a lot easier to configure for high enrichments. A centrifuge could be as small as 5 foot high, and about 6 inches wide - or bigger depending on requirements. You'd probably need somewhere between 1000 and 10000 if you wanted to make a one off weapon - although closer to 100,000 would be needed if you wanted to arm yourself to the teeth. Commercial reactor fuel plants are planned using millions of centrifuges.

Centrifuge plants can be very small - if you really wanted you could set up a 'micro plant' of a few hundred centrifuges in your garage - it would probably even run off a domestic electricity supply.

The catch is that they require incredibly precise engineering - there are very few manufacturers in the world that can make the necessary parts - and most are in the US, Europe, Russia and Japan (and understandably, the relevant governments like to know what they are making) and even the equipment to make the manufacturing tools is subject to modest scrutiny. Not only that, but you need to have specialist facilities to assemble the centrifuges - If you want 10,000 centrifuges you'll need probably a few hundred skilled technicians and lots of specialist tools and testing equipment.

There was a huge fiasco in 2001 when US intelligence intercepted a shipment of ultra-high precision high-strength aluminium tubes bound for Iraq. Similarly, it's known that Iran has been importing small numbers of both parts and the equiment to make the parts, and that they have built a few tens of centrifuges. However, just because no one knows about a major secret order of parts, doesn't mean that there hasn't been one.

Commercial Uranium enrichment brochure - includes pictures of a centrifuge setup

 

[BrownTown]

basically, no matter how you decide to enrich the uranium its hard to keep it secret. Of course in Iran's case we already know that they have this technology, the question is whether or not they are using it for electricity or to make nukes. Personally id think Iran could just use oil to make electricity, it would probably be much cheaper and wouldn't cause any controvery. But I think that htey realise that having a nuclear reactor gives you alot of leverage when it comes to bargaining with the US. They can always agree to dismantle it later in exchange for the US giving them something they want.

 

[LumbergTech]

Originally posted by: BrownTown
basically, no matter how you decide to enrich the uranium its hard to keep it secret. Of course in Iran's case we already know that they have this technology, the question is whether or not they are using it for electricity or to make nukes. Personally id think Iran could just use oil to make electricity, it would probably be much cheaper and wouldn't cause any controvery. But I think that htey realise that having a nuclear reactor gives you alot of leverage when it comes to bargaining with the US. They can always agree to dismantle it later in exchange for the US giving them something they want.

not to mention that somehow certain countries seem to think they have the right to own these weapons while others do not.....

my question about this whole thing ..how does iran not have the right to pursue nuclear energy?

 

[BrownTown]

yeah, it is interesting to see how the US and other countries try to decide who should and should not have certain technology. The US has sanctions against countries for pursuing nuclear technology and yet gave H bomb technology to the UK and most likely gave A bomb technology to Isreal, or at least tacitly supports their nuclear program. Fact of the matter is that the US has stockpiles of chemical and nuclear weapons. And also maintains several very virulent strains of virusses/bacteria as well as the technology to develop them into biologica weapons. Also, the US has used nuclear and chemical weapons in warfare, and yet claim that nobody else can even have access to this technology. Obviously its a double standard, but personally I still support it, I might not like the idea that so many countries possess these technologies now, but I sure as heck don't want anymore people to get them, especially countires that aren't very stable.

 

[dkozloski]

Why not do like the North Koreans and recover the plutonium from spent fuel rods. Then you can concentrate your efforts on soliciting bribes from other contries to make you stop.

 

[gsellis]

Interesting sidenote... They enriched the uranium for the WWII bombs at Oak Ridge. I suspect part of it was the power from TVA. My dad said they had to run lots of power lines. Problem, all of the US copper was going into brass production for bullets and shells. So, the Manhattan project was running powerlines made from silver. The moment the war was over, they riped them out and put up copper.

Dad had the inside track. BioChem at UT, then worked at Princeton testing stuff from Bikini tests. One of his managers was Einstein. Left that job to become a priest (Episcopal, not Catholic.)