I cannot say that terrorist threat to nuclear facilities is non-existent, but I do believe it is manageable. It think that as long as there are the proper safety and security protocols in place, the risk is minimal. There is always a chance something could happen, but I do believe it would be pretty unlikely.
There will be a terrorist threat any where you go. Whether a building, a boat, or a nuclear plant. I think the threat specifically to nuclear plants is minimal at best because there are extra safeguards in place to help protect us. Terrorists will have an easier time concentrating on other areas.
Terrorists pose no bigger threat to nuclear facilities than they do to other types of facilities. First, most nuclear facilities have very intricate emergency plans in action because nuclear power has been subjected to so much scrutiny over the years. So, in a sense, they would actually be a more difficult target for terrorists than other types of facilities. Second, striking a nuclear facility in a manner that it would cause severe damage takes considerable expertise about how nuclear power operates. Terrorists would need to spend a lot of time and money training themselves in the science of nuclear power.
The terrorist threat to nuclear facilities is not non-existent/manageable. Anything is possible when it comes to the threat of a nuclear attack on our own soil. We have precautions and procedures in place to try to keep this from happening but anything is possible. They could easily target a nuclear plant.
I'm pretty sure that a terrorist could fly a plane into at least one nuclear facility in this country and wreak a lot of havoc. I think we should be continuously monitoring ways to limit the risk of our nuclear energy facilities being attacked. I don't think it is manageable at this time.
Given the broad definition terrorism has included, especially when used by our governments, it could include a variety of criminals. Nuclear facilities will always be subject to possible attack, given they're capabilities to melt down and cause destruction. It is not safe if people assume terrorist will not attempt to attack these facilities, because there are groups who seek to destroy their opposition. This is a fact and there's no guarantee the safety is manageable, 100% of the time.
Someone, somewhere will find a way to get around the rules. Unfortunately, it is something someone may be able to hide. Where there is a will, there is a way. That is not to say that it is not important to try to manage, because managing it will decrease its existent, as laws and management does with most things. However, there will always be someone who tries to get around the rules. The better it is managed the less this will happen, but truth of the matter is that it will most likely not be able to be 100% managed, unfortunately.