My comment on 

The Biggest Nuclear Boondoggle Ever: Taxpayers, Pull out Your Wallet, Costs Exploded Again

by Wolf Richter, 15 October 2016

(in cache)

ITER uses the fusion of deuterium (D) and (radioactive) tritium (T). Each D-T-fusion produces an intermediate nucleus which emits a neutron having an energy of 14.1 MeV and is thereby receiving a recoil energy of 3.5 MeV (link).

These 17.6 MeV are 

(1) mostly turned into radiation, which Lars and Nick referred to as electrical  energy, but part of the 17.6 MeV is

(2) dispersed in nuclear reactions mostly in the reactor structure, e.g. for breeding T from lithium, and render stable reactor structure radioactive.

The radiation energy (1) ends up as thermal energy and is eventually converted by turbines into electrical energy like in conventional power plants.

Because of processes (2) a fusion reactor power plant poses a radioactive hazard. 

1. Containment of the bred T inventory in an accident is yet unsolved, and its release from one fusion power plant might double the present atmospheric tritium concentration on the earth (link).
2. The waste from fusion power plants contains radioisotopes with similar half-lives as waste from fission power plants. Comparing the hazards of fusion and fission waste is presently not possible because we do not know enough about waste behavior 
• in the repository, 
• in the isolating rock formations enclosing the repository, 
• in the biosphere and food chain and ultimately 
• in the living organisms (particularly its long-term radiation damage).

Version: 16 October 2016

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