Just some points
1) Chernobyl style reactors are designed to produce weapon grade plutonium. Without nukes no one would build such a reactor.
2) Todays non-chernobyl reactors are heavily influenced by the criteria for US Navy submarine reactors in the Cold War. Without WW2 there would be no Cold War, so other reactor designs are as likely to be standard as high pressure water cooled reactors. For example thorium reactors (far better from a civilian perspective), melted salt or heavy water moderated reactors (that could use non-enriched uranium, which the original Swedish nuclear program was interested in).
3) Why would Sweden be so engaged in nuclear power? They had (and have) a lot of hydroelectric energy that could be exploited faster and cheaper than building nuclear power plants. And without WW2 and the Cold War there would not be any Swedish nuclear weapon program, which lowers the interest for civilan nuclear power.
I can definetly see a non WW2 Sweden being the first to build a small experimental reactor, but not any bigger, comercial power plants.
there actually IS a potential narrative reason for the first nuclear reactor ITTL being more dangerous than it's OTL equivalent, but that could spoil some of the story. thanks for that on thorium reactors--i'll have to remember to take those into account. as to Sweden itself, that actually stems from one of my very earliest drafts of the story where i'd just written in "Sweden builds the first nuclear reactor in 1946" and it's evolved since then. the basic idea is that it just happens to be Sweden that gets the first reactor, not necessarily for military applications, but i could adjust my timetable a bit and have it such that the first reactor DOES inspire someone into thinking of military applications so they build a Chernobyl-style reactor elsewhere as well
Extremely unlikely to happen, typically nukes were not stored armed and were only armed just before use. Nukes are extremely hard to set off accidently in any case, unless the precise sequence of charges is used you get a fizzle not a detonation. You might somehow set a gun type off, 1 in a billion but it could happen, but absent wartime pressure that design is less likely to be used
for a bit of spoiling, the idea i'd come up with was that this Second Tunguska was the result of an early French nuke program (narrative-only, really; i'd noticed i hadn't given France many major technological milestones so i decided to give them the first nuke detonation
) which actually employs a good number of OTL Nazi scientists (they're just employed by France ITTL since Nazi Germany doesn't exist) and, in a convergence with OTL, develop the Nazis' loosely-attempted nuke (my reading turned up that the Nazi nuclear program was in a pretty piss-poor condition, and they'd planned to use a highly-enriched uranium core and a heavy water moderator which, as i understand it, would have gone supercritical and killed everyone there had they actually tried using it. i suppose i may have misread at least some of where i got this and it may have still be a reactor rather than an actual bomb, but then again that's why i keep posting these kinds of threads, to work out the kinks in the TL
also, i'd seen this post last night but was tired and decided to hold it off until the next morning, so here's my reply:
If it's built at a university, that likely means a research reactor, output of just a few MW, and likely using low-enriched fuel. Likely a less-than-stable design too, since research reactors are for just that, research.
good to know. though, as i'm sure we all know, people can be pretty stupid--even the smart ones
--so maybe they build a grid reactor instead of a research reactor, not realizing the consequences
(truthfully, probably not, but w/e)
