NK {we. think.} is working only with Pu, not U²³⁵. No 'separation' efforts (that anyone knows about -- but then, why would they know? -- ain't none of the spooks gots even a peek inside that Ideal-Cheney/Republican State.)

A simple {ie. "gun type"} device cannot be made with Pu, for inescapable physics reasons of pre-ignition cf. The Curve of Binding Energy. Now, it's just barely conceivable that Kim-Il-Egosan might force an expensive Proof of that principle: and this was it == Yup, gun-type, it be no workie.
{Hey, Shrub ain't the Only ideologue that flips coins for all decisions beyond the workings of his sparse supply of little-grey-cells.}

Implosion devices need that aberration-free ~perfectly uniform array of HE of varying er, brissance - to maintain the compression field for many 'shakes' of neutron multiplication. In that direction lies Efficiency (sorta the same simplest goal as Econ, eh?)

Same outcome as any silly gun try re this explosion: implosion lens perfection not achieved, ergo dud-level yield.

Note that Iran groks to fullness, the problem of undertaking Perfection in explosives, via stone knives and bearskins -

Moral?
WATCH the centrifuge folks. Almost anyone could get a gun device to work; insurance there consists of ... simply possessing enough excess material beyond calc. critical mass to ensure ignition, even if a Microsoft-grade design.

Corollary -
IF the NKers do manage world-death-class implosion techno to a fare-thee-Well.. guess how many .pdfs of that design shall escape the Invincible Bush Mouth-Quarantine and all subsequent threats to draft prepubescent Brownies and Boy Scouts, to surround the borders, tie banzai scarfs about pretty little heas and -- then invade.



Tragicomedy.. Love. It.


PS: remember.. we tested the scary/improbable implosion device at Alamogordo.
But dropped the gun-type Uranium bomb first: on Hiroshima
(that one wasted Lots of -235, but then we had built Oak Ridge for the Ages and had tons coming.)

In the final analysis ... everything else.

Dunno how widely (more to point: accurately) disseminated are the many tiny but crucial details of the implosion bomb. As of '06. Indeed, Hansen's coffee-table tome, US Nuclear Weapons displays photos of complete weapons, including those cute dunce-cap shaped, compact passengers on all those MIRVs {a techno which LLL essentially forced on the world/USSR completely gratuitously == assuring that most-lethal phase of the arms race - a book length dastardly deed, that.}

Unfortunately too, IMhO Hansen's book is entirely Too-fact-filled as regards the vast complexity of the various forms of Supers; the neat diagrams of the stages of the FFF (fission-fusion-fission) process -- I deem a real disservice to living things..

Because always: what every jackal or psychotic Really wants is the unlimited yield of a Super. Never mind how bulky ... the now insatiable demand for Stuff guarantees the continuing free-flow of all those container$. No matter what.

While most of those supercomputer hours were about improving, shrinking etc. I don't think there is anything easy about the implosion lens. Still, merely having a good hint of the idea of laminating various HE substances - is indeed a start. But remember how crude were the first studies at Los Alamos: trying merely (via "one fewer dimension") to neatly crimp test piece of metal pipe. (That was Kistiakowski's enigma.)

Hard to do a dry run on implosion, when everything is first compressed then flung apart - no?
(There was constructed a massive cylinder similar to a diver's decompression tank, hauled to Alamogordo - in the hope that it might serve to preserve the Pu, in event of a dud. It wasn't used; why eschewed? ... never heard.)

Another magical facet is that of the neutron-source initiator, usually a Polonium/Beryllium mixture == a small ball at exact center of the barely-subcritical assembly.

At least with the Pu, you can chemically test for purity - but there are aspects to the reactor configuration which -even there - can favor isotope mixes which are less contributory to an early fizzle. That's a Lot of reactor as well as Pu testing lore .. you can't Google for. Another + for meat.

Finally with the -235 gun-type: not a suitable trigger for making your own Super, later. And if you rush; if you try a lower than optimum %235 ... etc. Then there are the (free) DU or -238 'tampers' to ponder - nothing to lose, tossing in some scrap to accelerate the inferno. Especially if it doesn't need to be miniaturized for Efficiency.

Splendid physics for a most unsplendid coterie of mass assassins, no?
May the experimenters join Louis Slotin, the crew of the [link|http://www.radiationworks.com/sl1reactor.htm| SL-1], pinned to the roof by their control rods, et al -- reel soon now.

Areas of comfort? - well, I'm not aware of any info on the size/deliverability of the Pakistani, Indian devices; we can be sure though, that the (400+?) Israeli specimens are indeed deliverable. Still.. guess who's apt to be the first recipient of incoming?
Oh wait - Muricans, just 5 years after all that empathy -- may well be on the exact shit-list level of Jews, now. (I can't guess either.)



Maybe we'll all luck in, just by a zealot's sloth in the pesky details? :-)
Bloody likelier than that that we'll all wise up.