I did not drill down into the article references. But, I would expect NASA to "smell a rat" if the proposal was simply a hoax.
The idea seems to be to scale up an existing technology by adding a more powerful energy source to make the electricity needed to create the plasma and direct it aft. The proposal is to use a fission type nuclear reactor instead of solar cells. That seems logical and conceptually doable. We have already build nuclear fission reactors and operated them in space (the SNAP reactors) decades ago. So, it is just a scale-up issue for development, at least conceptually.
And the bit about shielding goes along with that. The shielding needed to keep the crew from getting seriously irradiated by the fission reactor in the spacecraft can also be part of the shielding needed to protect the crew from other radiation from the Sun and "cosmic rays".