The 'reporter' "was a principal research physicist at the Princeton Plasma Physics Lab until 1999. For 25 years he worked in areas of plasma physics and neutron production related to fusion energy research and development. He holds a PhD in astrophysical sciences from Princeton University."

Do you think it's perhaps possible that the author knows what he's talking about? If you'd continued reading after that second sentence you might have come across:

> In fact, these neutron streams lead directly to four regrettable problems with nuclear energy: radiation damage to structures; radioactive waste; the need for biological shielding; and the potential for the production of weapons-grade plutonium 239—thus adding to the threat of nuclear weapons proliferation, not lessening it, as fusion proponents would have it.

I don't understand why the OP considers sneaky Pu239 production a proliferation problem, but doesn't consider unaccounted for tritium in the fuel cycle and the general availability of Li6 to bread more tritium a proliferation problem. Anyone?

Tritium is useful only if you can manufacture a fission weapon in the first place. The vast majority of anti-proliferation efforts are aimed at preventing fission weapons capability. Preventing a nuclear weapons state from graduating from fission weapons to boosted-fission or full two stage thermonuclear is a much lower priority.

You can build a bomb with plutonium but no tritium, so if you want to prevent countries from going nuclear that's what you need to stop.

Also, the plutonium production is the bottleneck. E.g. this article about the Pakistan nuclear weapons program[0] estimated that the 50 MW nuclear reactor in Kushab could be used to produce 10kg of plutonium and 100g of tritium per year. The plutonium would be enough for about 2 bombs, while the tritium would be enough for 20.

[0] http://nuclearweaponarchive.org/Pakistan/PakArsenal.html

He describes plutonium production as achievable by placing uranium into the reactor.

To generate plutonium requires a supernova...

Or an energetic neutron source, which a fusion reactor provides.