I should have addressed this way back when, seem to have missed this for, oh, a year or so....
But the thing about radiation is that the accumulated rads won't go away with a failed save, I really do want the PCs worrying about how many rads they are picking up.
And that is represented by having the
effects of a failed save linger.
No - because the Rads
themselves accumulate. They don't just go away because something has already gone wrong.
The system that I eventually went with was poker chips - with values equal to the standard denomination - one rad is white, five rads red, ten rads blue, etc.. Trade them in when you get enough, and make a save when you get the next black chip (100) or when you have gained rads for two minutes in a row. (Not each round - each minute - so if you take three rads a minute for two minutes then you still need to make a save, even though you only soaked up six rads.) Effects until you get a black chip are minor - once you get a black chip then things get serious. Having a pile of chips gives the players something to worry about.

And the reason I was reviewing the thread was looking for Ilya von Kreiger, since the folks at Raging Heroes are giving the miniature that inspired her sisters -

Ilya's younger sister is crazier, and less stable, than she is. Her older (one eyed) sister fakes crazy, but is cold, ruthless, and more than willing to kill both of her sisters if (when) she finds out that they poisoned dear old dad.
She is less crazy but more dangerous - if she ends up in charge of the Kreigers then they will be around for a while.
And, like the rest of her family, she prefers to do any torturing herself rather than let a henchman do it.
The only difference there is that she will actually be looking for information, not
just finding sexual relief.
The Auld Grump