Earlier quoted context omitted.
From what I've read at just the level of Wikipedia, I'd guess yes. But nuclear physics just is not my field. I wanted my Ph.D. in mathematical physics, but all the physics courses I could find did the math in very sloppy ways, and my hope for any research progress in physics wanted to do the math with full care. I did get much of that math, but by then I was occupied with my money making work and didn't get back to p…
This seems to explain much of it: http://en.wikipedia.org/wiki/Wigner_effect Whatever production process partially relies on arranging the crystal structure of the metal to arrive at desirable properties, the neutrons disrupt it.
Okay, I'll accept that: What used to be
the usual isotopes of iron, carbon, aluminum,
etc. with some extra neutrons, after
whatever gamma rays, alpha particles, etc.
boil off, becomes some other isotope or
element that doesn't fit in the crystal
and, thus, makes the crystal brittle.