There is always something to learn, even if it's from a harmful event. So what exactly did we learn from these nuclear accidents? Let's start with the one that took place in Three Miles Island. On March 28, 1979 a most serious nuclear power plant accident took place place on the Three Mile Island in the history of this U.S commercial operating system. However grave this was, there were no deaths or injuries among the plant workers or the members of the community. The accident was a level five, and "the accident began with failures in the non-nuclear secondary system, followed by a human-operated relief valve in the primary system that stuck open, which allowed large amounts of nuclear reactor coolant to escape." (A Brief History of Nuclear Accidents Worldwide) Essentially, it was a nuclear meltdown based on a human mistake. After this incident, an initiation for a coolant testing program was created in the 1960's by the Atomic Energy Commission. Therefore, there is now a greater focus and more attention is being put on events like cooling accidents. Nuclear plant designs now undergo much more rigorous testing and have better validated computer models. there is now more investment and a great deal of effort into a sustained program to share operating experience to workers, the effort was put to improve the control room and make regulations to pay attention to every aspect of the control room designs. A lesson still being learned is that an increased level of attention is now paid to important components that don't deal with the reactor, but there is still work to be done on any vulnerable systems, which in turn gives them an appropriate level of attention. Lessons that are yet to be learned about this incident are that we "have not yet implemented an effective, adequately resourced, planned communications program that helps to ensure that the public and the media understand the importance of a strong nuclear energy sector." (Adams ANS Nuclear Cafe).