Nuclear Arms Control Treaties & Agreements: Discussion

Singular_Transform wrote:There is no relationship between the required ammount of Pu-239 and the yield of the weapon.

Ok. Why is that? Will you please elaborate?

owais.usmani wrote:

I would say this is because most if not all of the nuclear weapons today are thermonuclear devices. The plutonium is just used to start the reaction, the actual yield comes from the deuterium / tritium fuel.

Yes.
They need Pu-239 to make the smallest possible atomic bomb, with few kilotons of yield.

Check back the chronology of NK nuclear testes, and visibly the first ones was few kton ones, to test the primary, and after they iterated thorought the secondary mechanism .

Secondary needs same enrichted uranium , but most likely it is relatively small mass.

Yttrium Discord: China's rare-earth metals initiative could trigger a crisis in the US nuclear industry



In China, the question of how to respond to the new restrictive measures introduced against the PRC by the United States of America is being discussed. Against the background of agreements on a partial reduction of duties, Washington unexpectedly announced such a restriction as a ban on the entry into the United States of scientists and graduate students from the People's Republic of China. This decision was personally made by Donald Trump and is explained as a measure of protecting US intellectual property and technology.


First of all, we are talking about the ban on entry into the United States of those Chinese scientists who, as stated, "support the course on the merger of military and civilian technologies." Particular emphasis is placed on activities related to medical and biological work.

In China, they said that such a decision was considered discriminatory and said that the US administration itself was undermining the foundations of scientific and technical cooperation.

One of the areas where China is ready to take retaliatory measures against the United States is the export of rare-earth metals, without which today it is impossible to develop a number of high-tech industries.

To date, China has managed to become the largest producer of rare earth metals. In 2018, it accounted for 70-plus percent of the entire global market. At the same time, China previously noted the problem of the illegal export of rare earth metals to North America.

Thus, it is said about the export to the United States of such a rare-earth metal as yttrium, the United States does not have enough of its reserves to implement numerous projects. China is a leader in the extraction of this metal. In the United States, yttrium and its alloys are used, among other things, in the military, space, rocket and nuclear industries. According to the latest data, the development of a nuclear missile power plant based on yttrium alloy is underway. And this rare-earth material is used due to the fact that it does not interact with melts of uranium and plutonium.

A compound such as yttrium tetraboride YB 4 is used in the US nuclear industry .

This material has unique characteristics that allow it to be used as a basis for creating control rods of nuclear reactors.

If China completely closes the export of yttrium to the United States, this will cause a crisis in the entire nuclear industry. A sort of "yttrium of contention." That is why the United States decided to intensify negotiations with Japan, which also has yttrium reserves. But the problem is that the field is deep-sea, which means its development can be associated with huge costs.

https://topwar.ru/171697-ittrij-razdora-iniciativa-knr-po-redkozemelnym-metallam-mozhet-vyzvat-krizis-v-jadernoj-otrasli-ssha.html

owais.usmani wrote:I would say this is because most if not all of the nuclear weapons today are thermonuclear devices. The plutonium is just used to start the reaction, the actual yield comes from the deuterium / tritium fuel.

Singular_Transform wrote:
Yes.
They need Pu-239 to make  the smallest possible atomic bomb, with few kilotons of yield.

Check back the chronology of NK nuclear testes, and visibly the first ones was few kton ones, to test the primary, and after they iterated thorought the secondary mechanism .

Secondary needs same enrichted uranium , but most likely it is relatively small mass.

Thanks.

So in warheads carried by a Topol or a Trident in terms of percentage what's the mix (ballpark figure) between plutonium and deuterium / tritium fuel?

Enriched Uranium or Enriched Plutonium needs about 1kg to reach critical mass to explode... if critical mass for the material concerned is 800g then three blocks of 300 grammes that are smashed together to set off the weapon could be used (if the weapon was dropped and somehow two of the blocks were slammed together then it would not go off it needs all three blocks together to reach critical mass and explode.

The Uranium or Plutonium are the trigger... they superheat the hydrogen material in surrounding layers around the core to temperatures where they spontaneously fuse releasing vastly more energy and turn a fission nuclear explosion into a fusion thermonuclear boom.

With a fission weapon you can't have lumps of the material bigger than critical mass weight otherwise they would explode on their own... to make it bigger you need more pieces, but as you can imagine making it a lot more powerful is tricky because everything needs to be slammed together at once otherwise bits will be blown away and vapourised without exploding and adding to the power of the weapon.

With a hydrogen bomb the more hydrogen material you have the more there is to fuse and release energy... it is easier to scale up and make bigger...

Sujoy wrote:

Thanks.

So in warheads carried by a Topol or a Trident in terms of percentage what's the mix (ballpark figure) between plutonium and deuterium / tritium fuel?

The fission bomb part require 1-3kg of Pu-239, and 239 gramm of Pu-239 needs 2 gramms of deutherium and 3 gramm of tritium. (1:1:1 MOL ratio )



It is not fuel, more of a boost , to increase the efficiency of the fission bomb part.


The secondary parts need isotope pure lithium , lead or depleted uranium (later increase the yield twofold) and a fissible spark plug.

The Basic Principles of Russian State Policy in the field of Nuclear Deterrence is now in the public domain

http://publication.pravo.gov.ru/Document/View/0001202006020040?index=0&rangeSize=1

It is not fuel, more of a boost , to increase the efficiency of the fission bomb part.

In terms of conventional bombs, HE would be too dangerous to carry around and store if it readily exploded so it is designed to be resistant to heat or damage.

Take some plastic explosive and hit it with a hammer or get a lighter and set it on fire and it wont explode... or it shouldn't... it will burn though...

To get it to explode you need another explosion, so for plastic explosive to blow up you need an explosion to make it explode.

That explosion is called a primary charge or low explosive... a trigger... or a fuse.

With low explosive even a spark will set it off so blackpowder can be set off with a simple burning fuse or spark. A small Black powder charge could be used to set off a much bigger more powerful HE charge... the black powder charge wont be huge... it is not there to create the damage... just to start the HE exploding and it will do the damage.

It is the same with a hydrogen bomb... hydrogen atoms wont fuse together except at extremely high temperatures and high pressures.... it only happens naturally inside a star. To create conditions like those inside a star heavy elements of Uranium or Plutonium are split in a runaway nuclear (not chemical) reaction. The issue with Fission is that you create an explosion by having enriched atoms of the material of a certain mass or volume. Once you have that much material there then boom the reaction becomes a runaway reaction and boom.

Obviously if you need 1.5kgs of heavy elements to reach critical mass then you can't store 1.5kgs of that material in one place or boom it will react.

If you want a bigger explosion you need more mass, but the critical mass remains the same you can't just scale it up.

The minimum bomb size assuming 1.5kgs is critical mass could be two 750 gramme chunks of the material that are slammed together to form critical mass of 1.5kgs and boom. You could scale such a design up by making each of the two chunks heavier... but as they get closer to critical mass they get hotter... two 1.2kg masses wont go boom because that it not critical mass but it might be enough mass to generate temperatures of thousands of degrees C that melts the nose cone of the missile and has liquid uranium or plutonium dribbling down through it.

The easiest solution is a huge ball that has wedges like a pizza except instead of a flat disc with 6 or 8 pizza slices it is a 3D sphere with perhaps 50 segments that can all be pushed from the outside of the sphere into the centre to form a solid sphere of the material... each piece might be 100 grammes each but the 50 pieces added together make up a sphere of 5,000 grammes of 5kgs which will definitely explode.

100 gramme sections wont be big enough for them to get too hot though many bombs had air conditioning systems to keep the elements cool so they didn't damage parts of the weapon.

The simplest nuke was called a gun barrel nuke and had a sphere of material with a section missing. That section was at the other end of the bomb and mounted inside a gun barrel pointed at the main mass of material with a HE charge behind it. When the bomb went off the HE charge blew the missing piece of the sphere down the barrel and into the sphere... its mass together with the mass of the ball created a sphere of critical mass and boom.

To make it bigger and more powerful they needed more pieces... but if the pieces got too big and heavy they would get too hot... if they got to hot they might damage the HE or mechanism to throw the pieces together which might fail and lead to the bomb not exploding properly... that is why they needed to test them.

Imagine a ball like the one I mention above split up into 50 pieces that when slammed together make a ball of 5kgs mass... if critical mass for the material is 1.5kgs then if half those segments are slow and 2.5kgs of the sphere reach each other first then they might blow up and just vapourise the other 2.5kgs of heavy metals so the boom will only be half as big as you thought it would be.

Another design could be to use HE to increase the pressure inside the warhead so it acts like it is critical mass even though it is not and boom but you get a smaller boom than you would if you put two pieces together that reached the correct weight.

In their experiments to create fusion reactors one of the problems scientists are coming up against is that inside a star it is hot but it is also under enormous pressure... so while fusion in our sun might be taking place at 5 million degrees C to do the same here on earth you might need temperatures of 15 or 20 million degrees because the pressure inside the reactor is nothing like the pressure inside a star.

GarryB wrote:

And new IRBMs would not need nuclear warheads as guidance accuracy and performance means conventional warheads are sufficient.

.

If conventional warheads are sufficient then tell me, does one need to use over 500 nuclear warheads to destroy a factory or just 1?
There is no way in hell you are going to destroy anything significant with just a few conventional warheads, conventionally armed missiles are good only for conventional wars and nothing else.

With 1000 nuclear IRBMs one could pacify most of europe, whith 1000 conventional IRBMS one could not even destroy a single city no matter how accurate they are.

This the same retarded nonsense us MIC spokesmen always spew, this idea belong in a padded cell along with its creators.

I agree. A nuclear warhead would cause significantly more damage than any conventional warhead could.

If conventional warheads are sufficient then tell me, does one need to use over 500 nuclear warheads to destroy a factory or just 1?
There is no way in hell you are going to destroy anything significant with just a few conventional warheads, conventionally armed missiles are good only for conventional wars and nothing else.

You re confusing things here a bit.

Sometimes the target is rather small and sometimes it isn't.

Sometimes you can render a factory useless by destroying one relatively small but very essential building in that factory complex.

A good example was during WWII the Americans and British identified a couple of ball bearing factories in Germany that were essential to the German war effort... they in fact identified a couple of individual buildings within those factories that if destroyed could grind a lot of other industries and war efforts in the rest of Germany to a halt... literally a grinding halt... so with the world renowned accuracy of the Nordon Bomb sight they sent thousands of bombers with dozens of bombs each to hit it... it was a long and dangerous flight and when they got pictures back there were bomb craters everywhere... except the essential buildings... some of the bombers even dropped bombs on the wrong country. They went back several times and as you could tell from how the war ended they never managed to hit those buildings hard enough to actually destroy them.

Two 500kg bombs would have done the job if placed accurately... an Su-24 or Su-34 could have done the job with two FAB-500 bombs.

A ballistic missile like a Scud or a cruise missile could have done the job if they hit the target with accuracy.

In the 1980s the Soviets would have had to use a nuke armed cruise missile because their cruise missiles at the time had CEPs of 250m which is not precise enough for a kill with a conventional warhead, but with current missiles point targets can be hit and destroyed with precision and when the job is to take out one building it is counter productive to take out 10 square kilometres with the target when that 10 square kilometres includes lots of stuff you don't need or want to destroy.

Having conventional warheads means you can use it without escalating things past the nuclear threshold... and the US is talking about mininuke weapons they think they will be able to develop and use in conventional warfare... I don't think the Russians will agree to that of course...

With 1000 nuclear IRBMs one could pacify most of europe, whith 1000 conventional IRBMS one could not even destroy a single city no matter how accurate they are.

With 2-3 Poseidons they could probably pacify or at least flood much of coastal europe too.

With scramjet motors an intermediate range missile might just be an enlarged cruise missile with a simple but precisely designed jet engine, they could easily build tens of thousands of them... In fact the most expensive part of them is likely to be the nuclear warhead, but that nuclear warhead means they can't be used except in WWIII. Having a few thousand with conventional warheads means you can use them for other things too like dealing with ships or airfields launching attacks... to blunt the attack and punish the attacker...

I agree. A nuclear warhead would cause significantly more damage than any conventional warhead could.

Of course it will, but the goal of a missile attack is not always to do maximum damage.... sometimes there is a specific purpose like hit an ammo dump or HQ or comms centre...