Ken Kok is a nuclear engineer and leading member of the American Society of Mechanical Engineers advocating for advanced nuclear power technology with spent fuel recycling. In the late 1970’s and early 1980’s he became involved in both magnetic and laser fusion projects. His team built a series of simple models which showed how difficult maintenance would be. Much of their conclusions to his knowledge has not been examined. Hence, he stands by his 50-year prediction made in 1980 and feels that adding another 40-50 years sounds reasonable.