I also heard the number 50 , I think 10 years back. Even so, a clean energy is an urgency looking at the environmental degradation.

Second, I like to confess that I have not studied much about the other approaches being made. I am reading about this project since when I was in my secondaery school. That is why I concentrated only on this project. And if I'm not wrong this project has achieved most attention.

Third, I'm not sure about the problems you said. But yeah, there are so many issues associated with this project. for example, the constant bombardment of the high energy neutrons on the container vessel walls may damage the container. It is also claimed that the bombardments may induce radioactivity on the container walls. Another problem with the reactor is that the neutron fluxes may hamper the normal operation of the electromagnets of the tokamak. Safety measures and materials to address these problems are being studied by the ITER tem and the IFMIF. The project is facing many problems day by day. That is why it has missed many deadlines.