[Alt History] Alternative conclusion to the Pacific conflict in WW 2

[johndallman]

Originally Posted by ak_aramis

It's theoretically true that they keep for decades - but I've not heard of any off-the-shelf 1970's warheads being tested, and there are parts other than the radioactive which can degrade.

It's not clear that this has happened at all. Certainly it can't be done at present, owing to the test ban treaty.

[Fred Brackin]

Originally Posted by johndallman

It's not clear that this has happened at all. Certainly it can't be done at present, owing to the test ban treaty.

Before the end of testing some of the US tests were for research but others were indeed to verify that the arsenal was still functional.

You'd need fresh tritium for the cores of the big ones but that's injected during the arming process and it is not burdensome to keep up tritium production. It's replaced radium in "glow in the dark stuff.

Some very old designs had americium (I think) in their cores and that needed to eb replaced every 6 months but I believe all of those would have been phased out by now.

After that even the plutonium won't be bothered by a few measly decades. It's really only conventional aging and corrosion on the conventional components that might be a problem. The test ban treaty shouldn't stop you from double-checking those.

[johndallman]

Originally Posted by Fred Brackin

Some very old designs had americium (I think) in their cores and that needed to be replaced every 6 months but I believe all of those would have been phased out by now.

Do you mean polonium? That was used in the early "urchin" neutron initiators, but those designs have all gone now: they were very big and heavy.

After that even the plutonium won't be bothered by a few measly decades.

There's no problem with radioactive decay, but there have been corrosion problems.

[Fred Brackin]

Originally Posted by johndallman

Do you mean polonium? That was used in the early "urchin" neutron initiators, but those designs have all gone now: they were very big and heavy.
.

<shrug> It was something mixed with beryllium to enhance neutron production.

[Johnny1A.2]

Originally Posted by Fred Brackin

Before the end of testing some of the US tests were for research but others were indeed to verify that the arsenal was still functional.

You'd need fresh tritium for the cores of the big ones but that's injected during the arming process and it is not burdensome to keep up tritium production. It's replaced radium in "glow in the dark stuff.

Some very old designs had americium (I think) in their cores and that needed to eb replaced every 6 months but I believe all of those would have been phased out by now.

After that even the plutonium won't be bothered by a few measly decades. It's really only conventional aging and corrosion on the conventional components that might be a problem. The test ban treaty shouldn't stop you from double-checking those.

Granting that, though, machines long untested do run a higher risk of failure because of some 'unknown unknown' factor. Not that I think the bombs wouldn't work, just that I wouldn't be shocked if some failed for unpredictable reasons that cropped up over time.

[ak_aramis]

Originally Posted by Fred Brackin

After that even the plutonium won't be bothered by a few measly decades. It's really only conventional aging and corrosion on the conventional components that might be a problem. The test ban treaty shouldn't stop you from double-checking those.

The problem I see is that NASA has noted radioactive decay thermopiles seem to result in much more rapid corrosion and the thermocouples decay faster than expected (resulting in the failures of the Pioneers before expected failure dates); any such test on a nuke would require disassembly - which itself invalidates the mechanical test to some degree - because the presence/lack of radioactives is in fact a major issue to be tested for on the systems. And rapid radiation exposure in the lab is quite unlike long term radiation in the field, at least for thermopiles.

Plus, the initiator charge is a conventional explosive.

@Jason - not strangelovian at all. A very serious question.

One of the reasons the Nike missiles were removed from Alaska was that the missiles themselves were largely non-functional already (according to USAF text on Ballistic Missiles). Rockets really don't store all that well - they are not as corrosion resistant as normal constructs of the same materials because, largely, they're incredibly weight sensitive. The ICBMs and Anti-Ballistic-missile rockets (Nike, etc) were intended for ongoing replacement schedules.

And, as we see mechanical failures in more nuclear plants... they're sounding more like mechanical fatigue at higher than expected levels. Only 3 have been really notable failures - Chernobyl, Three-Mile Island, and Fukashima Daichi. (There is suspicion that one of the lost soviet nuclear subs may have also been a plant failure, rather than simply a dive below crush depth.)

Sure, they pulled the chem out of some WWII naval gun shells in the 1980's and refilled them - but keep in mind the actual mechanics are only added within seconds of going into the guns. They didn't use the WW II fuses nor the WW II powder-bags, nor even the WW II explosives in the shells. Just the shell-case. The army is doing so with 155 rounds, too. http://www.upi.com/Business_News/Sec...4521425048106/
http://www.army-technology.com/featu...ition-4583575/

[Fred Brackin]

Originally Posted by ak_aramis

The problem I see is that NASA has noted radioactive decay thermopiles seem to result in much more rapid corrosion and the thermocouples decay faster than expected (resulting in the failures of the Pioneers before expected failure dates); ]

Why would this be relevant to nukes? RTGs use isotopes with far shorter half-lives (c. three orders of magnitude) and don't have thermocouples to corrode anyway.

[ak_aramis]

Originally Posted by Fred Brackin

Why would this be relevant to nukes? RTGs use isotopes with far shorter half-lives (c. three orders of magnitude) and don't have thermocouples to corrode anyway.

Every dissimilar metal joint is effectively also a low efficiency thermocouple.

The neutron radiation of Pu239 is still notable, and can cause failures and radioactive metal decay. It's not been well tested, and the only data points on long term effects that are well reviewed are all from thermopiles using Pu238.

[The Colonel]

Originally Posted by johndallman

It's not clear that this has happened at all. Certainly it can't be done at present, owing to the test ban treaty.

I would imagine you could (and should) test microswitches, detonators and similar things in case of degradation...

[Irish Wolf]

Originally Posted by The Colonel

I would imagine you could (and should) test microswitches, detonators and similar things in case of degradation...

In fact, this is done, as part of the regular maintenance of the delivery system itself. Missiles and bombers are big, complex machines, with lots of moving parts; warheads, by contrast, are pretty simple in design. So long as the detonators work and the explosive blanket hasn't degraded, your bomb will go boom when you tell it too (or, under certain circumstances, when armed and subjected to given conditions - for instance, an armed warhead has to be kept away from an ongoing nuclear explosion, for fear the neutron flux will send the warhead supercritical too soon. Nobody wants their plane's bomb bay to suddenly imitate a small star).