Clarification needed.

The 93+2 exercise led, in 1997, to the Model Additional Protocol. The logic behind it was different — while full-scope-safeguards provided assurance that all nuclear materials were fully accounted for in exclusively peaceful activities, the Additional Protocol was intended to reassure that there was no clandestine nuclear activity being undertaken.

Can i makeover the sentence written in blue something like... "The logic behind this protocol was to assure that all nuclear materials fully accounted for peaceful activities and not clandestine activity being undertaken in the former Additional Protocol.

Also, please explain the meaning of "accounted for in" in original sentence.

I doubt weather "for & in" exclusively express a preposition here. I just want to cut short the entire line, but also don't want, in any way, to minimize the essence it convey. . Please also tell if the "makeover" sentence is compromising the quality and beauty of the original line.

Sincerely waiting for a kind response.