The United States was unable to stop publication of such materials because the courts found that all the essential information was available from unclassified sources. Nuclear reactors were invented to create plutonium, which is an artificial substance used to make the first atomic bomb and the Nagasaki bomb, and is used to make the triggers for all the hydrogen bombs. Plutonium is the deadliest substance you can conceive of. One pound, evenly distributed, is sufficient to kill every man, woman and child on planet earth. Human beings are the creatures that are most subject to radiation damage, and thousands of pounds of plutonium from bomb tests or leakage from nuclear powerplant smokestacks, contaminate the soil all over the world.
Every nuclear reactor produces enough plutonium to make a bomb, about every ten days.
At one time it was very expensive and difficult to separate plutonium from the other ingredients in a nuclear reactor, but modern technology has made reprocessing much simpler and cheaper. The United States has spent billions in recent years digging massive holes and caverns under New Mexico, Arizona and Nevada. More massive excavations are to take place under Texas. The government's plan is to take all the reactor waste from American reactors sold all over the world, and to bury it under the United States. The United States doesn't want other countries extracting the plutonium for their own bombs, so we've agreed to take back the waste from Bechtel and Westinghouse's nuke plants from all over the world.