I remember to have seen a documentary about competing US and soviet programs to build nuclear powered jet engines. Both programs where eventually deemed unfeasible.
But I do remember that the soviets actually flew around with nuclear powered jets on a bomber. But it left a trail of radiation. Oh and most of the crew died soon after flying, or developed horrible illnesses. Now why would this be a bad idea??
For one, the nuclear engines never gave enough power to keep the plane in the air, so it needed auxilliary engines to stay airborne. Its also not a good idea to fly around in an aircraft that constantly spews out high levels of radiation, a big fat radiation plume would also be detected very easily. Proper shielding for a nuclear reactor would be waaaaay to heavy and if you dont shield it your aircrew will die!
So there are endemic problems with nuclear powered aircraft that two of the most powerfull powers that ever existed could not solve. So the Argentinians would never ever ever be able to solve these problems. I find it highly doubtfull that they even seriously considered it.