Vulnerability of nuclear plants to attack

Nuclear plants are big buildings filled with lots of very important and very complicated things. The reason why we worry about them being attacked is because if someone does something bad to the inside of the nuclear plant it can cause a very big explosion and lots of dirty pollution. Bad guys could take control of the plant and cause it to blow up, so it's important to keep them safe from attack. That means having strong security guards and lots of barriers that make it very hard for bad people to get close enough to the plant to attack it.