[HN Gopher] US moves closer to underground testing of nuclear we...
       ___________________________________________________________________
        
       US moves closer to underground testing of nuclear weapons without
       any explosions
        
       Author : giuliomagnifico
       Score  : 18 points
       Date   : 2023-10-08 21:47 UTC (1 hours ago)
        
 (HTM) web link (qz.com)
 (TXT) w3m dump (qz.com)
        
       | m3047 wrote:
       | "...where scientists have been conducting subcritical experiments
       | since 1995..."
        
         | perihelions wrote:
         | Right. There's been 33 since then, with two more planned in
         | 2024.
         | 
         | The title is pretty misleading, in that respect. The US can't
         | be "moving closer to" something that it's _already_ doing.
         | 
         | - _" Currently, the NNSA is building two new subcritical
         | experimental testbeds at the U1a Complex in Nevada. The
         | testbeds will provide data to help address stockpile questions,
         | with a special focus on the impact of plutonium aging on weapon
         | performance. Since halting underground nuclear explosive
         | testing, the United States has executed 33 subcritical
         | experiments. The United States is preparing to execute two
         | subcritical experiments in 2024 and plans to conduct
         | approximately three subcritical experiments per year by the end
         | of the decade."_
         | 
         | https://www.energy.gov/nnsa/articles/remarks-nnsa-administra...
        
       | tpmx wrote:
       | _Scientists call it "tickling the dragon's tail, " Custer said,
       | because the experiment approaches but stays below the stage at
       | which the fission of nuclear materials sustains an ongoing series
       | of chain reactions._
       | 
       | According to https://en.wikipedia.org/wiki/Demon_core Feynman was
       | the person behind that expression.
       | 
       |  _Scientists referred to this flirting with the possibility of a
       | nuclear chain reaction as "tickling the dragon's tail", based on
       | a remark by physicist Richard Feynman, who compared the
       | experiments to "tickling the tail of a sleeping dragon"._
        
         | nico wrote:
         | From the Wikipedia article:
         | 
         | > The demon core was a sphere of plutonium that was involved in
         | two fatal radiation accidents when scientists tested it as a
         | fissile core of an early atomic bomb
         | 
         | > In both cases, an experiment was intended to demonstrate how
         | close the core was to criticality with a tamper, but the core
         | was accidentally put into a critical configuration
         | 
         | That doesn't sound very reassuring
        
           | tpmx wrote:
           | You'd imagine they have a learned a bit since then. And it's
           | underground.
        
           | [deleted]
        
       | jbandela1 wrote:
       | This would be a great plot opener for a thriller book:
       | 
       | The testing reveals that none of initial batch of warheads tested
       | work. Worry spreads throughout the scientists as they broaden the
       | testing none of the warheads work.
       | 
       | There is full on panic now that the entire US nuclear deterrent
       | has evaporated. If foreign powers found out, the US and all
       | nations under the nuclear umbrella would be subject to blackmail.
        
       | [deleted]
        
       | neetdeth wrote:
       | Unpopular opinion: Just bring back testing.
       | 
       | I've seen way too many people speculate recently that Russia's
       | nuclear arsenal possibly doesn't work. This is incredibly
       | dangerous.
       | 
       | What's the plan when humanity is so many decades into a test ban
       | that nuclear detonations are a generational memory? Something
       | akin to a myth. The relative stability afforded by MAD doctrine
       | is bound to decline.
        
         | dboreham wrote:
         | Fair point. Perhaps also worth noting that an "end-to-end" test
         | has been performed by the US exactly once.
        
           | tpmx wrote:
           | (Twice.)
           | 
           | I find it somewhat incredible from a pure engineering point
           | of view that Trinity worked in the first test and that both
           | Little Boy (#2) and Fat Man (#3) also worked.
        
           | andbberger wrote:
           | which test was that
        
             | perihelions wrote:
             | Dominic / Frigate Bird in 1962.
             | 
             |  _" Frigate Bird was the only US test of an operational
             | ballistic missile with a live warhead."_
             | 
             | https://nuclearweaponarchive.org/Usa/Tests/Dominic.html
        
         | bob1029 wrote:
         | I agree.
         | 
         | How long until subcritical experiments need to turn into
         | supercritical ones? At some point you have to do an integration
         | test or no one can say anything of certainty.
         | 
         | Proving a sample of plutonium emits the right dose of radiation
         | when whacked appropriately is a great starting point, but it
         | doesn't validate the rest of the weapon system.
         | 
         | You could test the bombs with inert cores to prove everything
         | _outside_ the physics package is valid, but there is still the
         | "but sometimes" bullshit space where perhaps the core seems
         | good on paper but the neutron initiator has an undue delay
         | related to aging circuitry and we lose 80% of the expected
         | yield. Whatever the case - in isolation both system elements
         | might test OK but they could still fail when combined.
         | 
         | I feel like the dial-a-yield devices are most precarious (e.g.
         | B61). How could you _really_ know you aren 't going to
         | over/undershoot massively? What is the range of uncertainty on
         | that system after 3 decades?
        
         | justahuman74 wrote:
         | Also: we don't want someone lobbing 10x as many warheads
         | because they only think half work
         | 
         | I think a few countries will feel a bit vulnerable at some
         | point (like Poland/Japan/Australia/SouthKorea) and start to
         | question if concepts like the US umbrella is truly a sufficient
         | deterrent, and probably start their own development/testing
        
           | giantg2 wrote:
           | If they're lobbing any, they're probably lobbing most
           | anyways.
        
       | perihelions wrote:
       | Relevant and interesting:
       | 
       | https://www.energy.gov/nnsa/articles/remarks-nnsa-administra... (
       | _" Remarks by NNSA Administrator Jill Hruby at the [Comprehensive
       | Nuclear-Test-Ban Treaty]: Science and Technology Conference
       | 2023"_)
        
       ___________________________________________________________________
       (page generated 2023-10-08 23:01 UTC)