Genuine question, are you attempting to assert that a proliferation of Civil Nuclear Reactor technology has no meaningful impact on nuclear defence proliferation and even might prevent nuclear defence technology proliferation.
No, not really.
I am more suggesting that The two branches of technology are linked in much the same way as Steel production can be used to make both Motor Cars and Battleships.
Obviously they are linked technologies based on similar knowledge.
However, for a NPT signee to attempt a clandestine weapons program using typical civil nuclear tech to manufacture weapons grade Plutonium is tricky. (And that is before we go into the issue of actually turning that Plutonium into a reliable and practical device without anybody noticing)
As I said, a PWR type reactor (The most popular type for civil reactors) is extremely impractical for this. weapons Plutonium breeding requires the fuel to only remain in the reactor for a short time (Otherwise you end up with the wrong sorts of Plutonium and the bomb wont work properly) Typical PWRs need to be shut down for refuelling and the frequent refuelling cycle to produce weapons material would be very obvious and would give the game away.
Obviously in the case of India the Canadian/Indian reactor, observably it did generate weapons grade plutonium.
A Pressure tube reactor like a CANDU
could be operated in a clandestine manor since individual tubes could be refuelled while the reactor was operating under load.
And then you would need a "Windscale" to carry out the reprocessing and chemical separation, again, difficult to hide.
But, for all sorts of reasons, A clandestine program based on uranium enrichment is a far more practical route nowadays. Not least because PWRs require enriched fuel and (IIRC) in terms of "Separative Units" (A measure of how much effort a degree of enrichment entails) the 5% or so required for a typical PWR is nearly halfway there as far as weapons grade enrichment is concerned.
(It is complicated further because Nuclear Marine propulsion typically uses near bomb grade uranium, so non-nuclear weapon states might still have an entirely legitimate requirement for 90%+ HEU)
Overt Nuclear weapons states typically use special reactors for Plutonium production, though the early MAGNOX power stations were based on Plutonium production piles (And were intended as dual purpose reactors)
Similarly the RMBK Chernobyl reactor was also based on military piles and was likely also designed to serve a dual function (It was also a pressure tube design)
TL;DR
Civil and Military Nuclear technologies
can crossover (But with a lot of effort and the acceptance of significant difficulties that means that this is only practical for a clandestine program) but typically the technical objectives are sufficiently different that different technical approaches are required which are not really compatible with one another.