party_pants said:

…

It’s been over 70 years now since the first simple nuclear weapons were developed, so in some sense it is 70 year old technology. Is the technology now relatively more simple for other nations to pursue?

Addressing the other side of the original question.

Some technologies have hardly advanced at all in 60 years. And those that have advanced have not been particularly useful for fission bomb proliferation.

Craftsmanship hasn’t improved significantly. Casting metals is much the same. Turning and drilling, tapping and screwing are much the same. Machining of explosives is much the same. Welding technology hasn’t improved much since 1960.

There’s been no new isotopes that are useful for fission or fusion since Californium was discovered in 1950, and the production of exotic isotopes has dropped off since the end of the 1960s.

Just about everything now known about nuclear stability and binding energy was known in 1969.

So far as I know, C-4 in 1958 and Semtex in 1964 are the most recent useful bulk explosives. Google says little about the history of post-1960 military explosives.

There was a greater variety in nuclear reactor types back in 1960 than there are today. For example, at the current time there are only two breeder reactors in the world, both in Russia and both a holdover from 1980 technology.

For low background steel, it has to be sourced from sunken ships prior to 1945.

Increasing OH&S has made proliferation more difficult.

Real advances in technology since then haven’t been much use for fission bomb proliferation. Technologies such as:

• Computerisation
• Mass production
• Plastics
• Carbon-epoxy composite

They sort of have niche uses, but nothing significant from a non-proliferation viewpoint.

So far as I know, C-4 in 1958 and Semtex in 1964 are the most recent useful bulk explosives. Google says little about the history of post-1960 military explosives.

MOAB, FOAB bombs

Cymek said:

So far as I know, C-4 in 1958 and Semtex in 1964 are the most recent useful bulk explosives. Google says little about the history of post-1960 military explosives.

MOAB, FOAB bombs

Even the really nasty bombs were invented quite early on. Cobalt, Neutron, EMP.

Tamb said:

Cymek said:

So far as I know, C-4 in 1958 and Semtex in 1964 are the most recent useful bulk explosives. Google says little about the history of post-1960 military explosives.

MOAB, FOAB bombs

Even the really nasty bombs were invented quite early on. Cobalt, Neutron, EMP.

Perhaps antimatter bombs are the next step if that’s possible

Cymek said:

Tamb said:

Cymek said:

So far as I know, C-4 in 1958 and Semtex in 1964 are the most recent useful bulk explosives. Google says little about the history of post-1960 military explosives.

MOAB, FOAB bombs

Even the really nasty bombs were invented quite early on. Cobalt, Neutron, EMP.

Perhaps antimatter bombs are the next step if that’s possible

rubs hands

mollwollfumble said:

Craftsmanship hasn’t improved significantly. Casting metals is much the same. Turning and drilling, tapping and screwing are much the same. Machining of explosives is much the same. Welding technology hasn’t improved much since 1960.

Quite a lot for most of those actually.
The CNC machinery available now is an order of magnitude better than only a couple of decades ago. Metallurgy as well. Casting has also improved, for example larger aluminium casting are now possible.
The types of welding since 1960 has grow substantially, for example electron beam welding, friction stir welding, etc.
We also have 3D metal printing machines, which in the 60’s would have been UFO technology.

A real example of how metallurgy has improved is from about ten years or so ago, when Toyota was trying to get more revs out of their US-based Indycar engines. They were required to use conventional coil valve springs, and the best they could do safely was 15,000 rpm. They did a bunch of research & development, and were able to finally get 16,000 from their engines.
Jet engine turbine blades are also massively better than they were in the 60’s. The technology that goes into them is extremely impressive. Watch this video – How to build a jumbo jet engine
After about the 22 minute mark, they talk about how important the cooling is for the single-crystal turbine blades they use – “They operate in an environment 300° hotter than their melting point”.

Cymek said:

So far as I know, C-4 in 1958 and Semtex in 1964 are the most recent useful bulk explosives. Google says little about the history of post-1960 military explosives.

MOAB, FOAB bombs

Ta. I’ll look them up.

I can see a few ways in which more recent technology can aid nuclear proliferation. From https://www.researchgate.net/publication/229000361_Military_High_Explosives

• Most bombs still use lead azide detonators, which are 1920s technology. But technologies now exist for setting off a secondary (conventional) high explosive without the need for a detonator. “A metal wire embedded in secondary high explosive material is charged with a very high electrical current. The sudden evaporation of the wire and the resulting shock-wave is sufficient to initiate the surrounding secondary explosive. Another new method is the direct initiation of secondary explosives by a laser beam.”

• A better high explosive is CL-20, also known as HNIW. This is 2,4,6,8,10,12-(hexanitro- hexaaza)-tetracyclododecane, a nitramine compound, similar to RDX and HMX. HNIW has a detonation velocity of 9400 m/s, which cannot be reached by any other organic explosive at the present time (2004). CL-20 was invented and synthesized by A.T. Nielsen in 1989 in the US China Lake facility.

• Plastics technology has advanced to the point where “cast and cure” plastic binders for high explosives can be made to have a range of desired physical properties.

• w.silex.com.au/SILEX-Laser-Uranium-Enrichment-Technology was invented in Lucas Heights in Sydney during the 1990s. It has been licensed to a Japanese company, and they are trying to sell it to the USA. “The two methods of uranium enrichment used to date have been the now obsolete Gas Diffusion (first generation) and Gas Centrifuge (second generation). Silex’s third generation laser-based process provides much higher enrichment process efficiency compared to these earlier methods, potentially offering significantly lower overall costs.” See also https://www.iranwatch.org/library/ncri-press-conference-irans-project-build-neutron-initiator-2-3-https”, which says that in Nov 2004, “I revealed information on two new nuclear sites that are involved in laser enrichment”.

In better news, the use of Polonium-210 and beryllium in producing a neutron pulse to trigger plutonium fusion hasn’t changed since the technology was introduced in 1945.

mollwollfumble said:

Cymek said:

So far as I know, C-4 in 1958 and Semtex in 1964 are the most recent useful bulk explosives. Google says little about the history of post-1960 military explosives.

MOAB, FOAB bombs

Ta. I’ll look them up.

I can see a few ways in which more recent technology can aid nuclear proliferation. From https://www.researchgate.net/publication/229000361_Military_High_Explosives

• Most bombs still use lead azide detonators, which are 1920s technology. But technologies now exist for setting off a secondary (conventional) high explosive without the need for a detonator. “A metal wire embedded in secondary high explosive material is charged with a very high electrical current. The sudden evaporation of the wire and the resulting shock-wave is sufficient to initiate the surrounding secondary explosive. Another new method is the direct initiation of secondary explosives by a laser beam.”

• A better high explosive is CL-20, also known as HNIW. This is 2,4,6,8,10,12-(hexanitro- hexaaza)-tetracyclododecane, a nitramine compound, similar to RDX and HMX. HNIW has a detonation velocity of 9400 m/s, which cannot be reached by any other organic explosive at the present time (2004). CL-20 was invented and synthesized by A.T. Nielsen in 1989 in the US China Lake facility.

• Plastics technology has advanced to the point where “cast and cure” plastic binders for high explosives can be made to have a range of desired physical properties.

• w.silex.com.au/SILEX-Laser-Uranium-Enrichment-Technology was invented in Lucas Heights in Sydney during the 1990s. It has been licensed to a Japanese company, and they are trying to sell it to the USA. “The two methods of uranium enrichment used to date have been the now obsolete Gas Diffusion (first generation) and Gas Centrifuge (second generation). Silex’s third generation laser-based process provides much higher enrichment process efficiency compared to these earlier methods, potentially offering significantly lower overall costs.” See also https://www.iranwatch.org/library/ncri-press-conference-irans-project-build-neutron-initiator-2-3-https”, which says that in Nov 2004, “I revealed information on two new nuclear sites that are involved in laser enrichment”.

In better news, the use of Polonium-210 and beryllium in producing a neutron pulse to trigger plutonium fusion hasn’t changed since the technology was introduced in 1945.

What is a good use for nuclear weapons, perhaps if radiation could be reduced they could be used for large scale excavation but they really only seem good for destruction.
Spacecraft propulsion perhaps

Cymek said:

What is a good use for nuclear weapons, perhaps if radiation could be reduced they could be used for large scale excavation but they really only seem good for destruction.

Spacecraft propulsion perhaps

Agree. Spacecraft propulsion perhaps.

I do like their use for making harbours. And using them for mining is not too bad an idea. Good design can minimise radiation.

If I wanted to minimise radiation from a nuclear explosion, I would not use enriched or natural uranium for any component. Only top quality plutonium, eg. pure 239Pu, or more expensive curium or californium, and possibly lithium or tritium for an energy boost. There are many other neutron-absorbing materials that must be avoided.

That would actually be an interesting challenge. Design a nuclear explosion to minimise radiation in say two energy ranges.

Cymek said:

What is a good use for nuclear weapons, perhaps if radiation could be reduced they could be used for large scale excavation but they really only seem good for destruction.
Spacecraft propulsion perhaps

Ядерные взрывы для народного хозяйства

> Ядерные взрывы для народного хозяйства

“In the period from 1965 to 1988, 124 peaceful nuclear explosions were carried out on the territory of the USSR as part of the implementation of the state program Nuclear Explosions for the National Economy, of which 117 were outside the borders of nuclear weapon test sites. All nuclear explosions were underground.

Spiny Norman said:

mollwollfumble said:

Craftsmanship hasn’t improved significantly. Casting metals is much the same. Turning and drilling, tapping and screwing are much the same. Machining of explosives is much the same. Welding technology hasn’t improved much since 1960.

Quite a lot for most of those actually.
The CNC machinery available now is an order of magnitude better than only a couple of decades ago. Metallurgy as well. Casting has also improved, for example larger aluminium casting are now possible.
The types of welding since 1960 has grow substantially, for example electron beam welding, friction stir welding, etc.
We also have 3D metal printing machines, which in the 60’s would have been UFO technology.

A real example of how metallurgy has improved is from about ten years or so ago, when Toyota was trying to get more revs out of their US-based Indycar engines. They were required to use conventional coil valve springs, and the best they could do safely was 15,000 rpm. They did a bunch of research & development, and were able to finally get 16,000 from their engines.
Jet engine turbine blades are also massively better than they were in the 60’s. The technology that goes into them is extremely impressive. Watch this video – How to build a jumbo jet engine
After about the 22 minute mark, they talk about how important the cooling is for the single-crystal turbine blades they use – “They operate in an environment 300° hotter than their melting point”.

OK. Yes. Submerged arc welding technology also improved circa 1990 for welding really thick materials. I don’t see much application for friction stir or submerged arc welding here.

I don’t know electron beam welding, sounds promising. Welding of thin sheets of difficult alloys without warping would be a key need for fission bombs.

I’ve seen some 3-D printed titanium, but it’s more like sintered than cast, lightweight but highly porous. I have heard that the porosity problem has been largely overcome.

> conventional coil valve springs, and the best they could do safely was 15,000 rpm. They did a bunch of research & development, and were able to finally get 16,000 from their engines.

Any idea how? Spring steels “are generally low-alloy manganese, medium-carbon steel or high-carbon steel with a very high yield strength.”

> single-crystal turbine blades

Are these getting to be old technology now? I first heard about them in the 1970s.

I wonder about the development of glues. Could an atomic bomb be glued together?

> That would actually be an interesting challenge. Design a nuclear explosion to minimise radiation in say two energy ranges.

Here’s a list of elements that it is safe / not-safe to irradiate with neutrons.

Minimising nuclear radiation for civilian explosions.

Elements you want to avoid irradiating. This table excludes absorption cross section, and is solely based on the production by the absorption of a single neutron of isotopes with half lives between one fortnight and one billion years. Shorter than one fortnight and the radiation decays rapidly. Longer than one billion years and the radiation is weak.

Safe: H, He, Li, B, N, O, F, Ne, Na, Mg, Al, Si, K, Ti, V, Mn, Cu, Ga, As, Br, Rb

Deuterium – safe because of low absorption cross section, but that isn’t considered here. Produces Tritium (12.32 y).

Beryllium – used as a trigger inside Pu bombs. Produces 10Be (1.4e6 y).

Carbon – 12C is safe, but 1.1% of natural carbon is 13C which becomes 14C (5,700 y).

Phosphorus – All natural phosphorus becomes 32P (14.3 d).

Sulfur – 32S is safe, but 4.25% of natural sulfur is 34S which becomes 35S (87.37 d).

Chlorine – 76% of natural chlorine is 35Cl which becomes 36Cl (3.0e5 y).

Argon – 40Ar is safe, but 0.3% of natural argon is 36Ar which becomes 37Ar (35.0 d).

Calcium – 40Ca becomes 41Ca (10,200 y). Minor component 44Ca also becomes a problem.

Scandium – 45Sc becomes 46Sc (83.79 d).

Chromium – 52Cr is safe, but 4.345% of natural chromium is 50Cr which becomes 51Cr (27.7 d).

Iron – 56Fe is safe, but 5.845% of natural iron is 54Fe which becomes 55Fe (2.744 y).

Cobalt – 59Co becomes 50Co (1925 d).

Nickel – 58Ni becomes 59Ni (76,000 y).

Zinc – 64Zn (49% of natural Zn) becomes 65Zn (244 d). Other isotopes are safe.

Germanium – 70Ge (20.6% of natural Ge) becomes, after beta decay and electron capture, 73As (80.3 d).

Selenium – 78Se (23.8% of natural Se) becomes 79Se (29,500 y).

Krypton – 84Kr becomes 85Kr (10.75 y).

Strontium – 88Sr becomes 89Sr (50.5 d). Note, this is not the infamous strontium-90.

etc. Rather a lot of natural elements are not safe to irradiate, unless the fast neutron absorption cross section happens to be small.

You may want to eliminate isotope 44Fe from the iron in your bomb.

mollwollfumble said:

> That would actually be an interesting challenge. Design a nuclear explosion to minimise radiation in say two energy ranges.

Here’s a list of elements that it is safe / not-safe to irradiate with neutrons.

Minimising nuclear radiation for civilian explosions.

Elements you want to avoid irradiating. This table excludes absorption cross section, and is solely based on the production by the absorption of a single neutron of isotopes with half lives between one fortnight and one billion years. Shorter than one fortnight and the radiation decays rapidly. Longer than one billion years and the radiation is weak.

Safe: H, He, Li, B, N, O, F, Ne, Na, Mg, Al, Si, K, Ti, V, Mn, Cu, Ga, As, Br, Rb

Deuterium – safe because of low absorption cross section, but that isn’t considered here. Produces Tritium (12.32 y).

Beryllium – used as a trigger inside Pu bombs. Produces 10Be (1.4e6 y).

Carbon – 12C is safe, but 1.1% of natural carbon is 13C which becomes 14C (5,700 y).

Phosphorus – All natural phosphorus becomes 32P (14.3 d).

Sulfur – 32S is safe, but 4.25% of natural sulfur is 34S which becomes 35S (87.37 d).

Chlorine – 76% of natural chlorine is 35Cl which becomes 36Cl (3.0e5 y).

Argon – 40Ar is safe, but 0.3% of natural argon is 36Ar which becomes 37Ar (35.0 d).

Calcium – 40Ca becomes 41Ca (10,200 y). Minor component 44Ca also becomes a problem.

Scandium – 45Sc becomes 46Sc (83.79 d).

Chromium – 52Cr is safe, but 4.345% of natural chromium is 50Cr which becomes 51Cr (27.7 d).

Iron – 56Fe is safe, but 5.845% of natural iron is 54Fe which becomes 55Fe (2.744 y).

Cobalt – 59Co becomes 50Co (1925 d).

Nickel – 58Ni becomes 59Ni (76,000 y).

Zinc – 64Zn (49% of natural Zn) becomes 65Zn (244 d). Other isotopes are safe.

Germanium – 70Ge (20.6% of natural Ge) becomes, after beta decay and electron capture, 73As (80.3 d).

Selenium – 78Se (23.8% of natural Se) becomes 79Se (29,500 y).

Krypton – 84Kr becomes 85Kr (10.75 y).

Strontium – 88Sr becomes 89Sr (50.5 d). Note, this is not the infamous strontium-90.

etc. Rather a lot of natural elements are not safe to irradiate, unless the fast neutron absorption cross section happens to be small.

You may want to eliminate isotope 44Fe from the iron in your bomb.

> Chlorine – 76% of natural chlorine is 35Cl which becomes 36Cl (3.0e5 y).

This seems to be the only long term trouble caused by irradiating seawater.

> Iron – 56Fe is safe, but 5.845% of natural iron is 54Fe which becomes 55Fe (2.744 y).

So be nice to the environment and remove the 54Fe from the iron in your nuclear bomb.

> Cobalt – 59Co becomes 50Co (1925 d).

Oops, 60Co = cobalt-60, very famous, and infamous.