Nuclear materials are most secure in Australia, which scored 93 points on the index. Switzerland and Canada followed behind. On the other hand, nuclear materials were least secure in North Korea.
Overall and category scores are scored 0 to100 where 100 equals the most favorable nuclear material security conditions.
The Nuclear Security Index includes five categories comprising 18 indicators to assess the nuclear material security conditions in 176 countries, 32 with one kilogram or more of weapons-usable nuclear materials and 144 with less than one kilogram or no weapons-usable nuclear materials. The five key factors the index evaluated are (1) quantities and sites, (2) security and control measures, (3) global norms, (4) domestic commitments and capacity, and (5) societal factors.