Materials optimised for low activation under neutron irradiation would be used in a full fusion energy economy. Unfortunately, these are not yet qualified for use in nuclear installations. Nevertheless most activated materials generated by the non-optimum materials used in ITER during its life can be cleared from regulatory control or recycled after 50 - 100 years.

The amount, isotopic content, activity and radiotoxicity of waste arising over the whole life of ITER has been calculated. The amount of waste ultimately to be disposed of has been estimated provisionally on the basis of "clearance". According to this IAEA concept, activated materials of known composition can be released from regulatory control ("cleared") if their activation levels are less than the specified level, and used unrestrictedly in the future.

Radioactive materials arising during operation and remaining after final shutdown include activated materials (due to fusion neutrons) and contaminated materials (due to tokamak dust - mainly beryllium and some activated material such as tungsten), activated corrosion products, tritium, and mixtures thereof. Due to decay and decontamination, a significant fraction of activated material, increasing with time, has the potential to be cleared.

The present assumption is that radioactive material not below the clearance level after 100 years is "waste", requiring disposal in a long-term repository. Estimates of ITER material masses show that about 30,000 t of material will be radioactive at shutdown, and that 80% of that can be cleared within 100 years.

However, quantity of waste is not the consideration which makes fusion potentially so attractive. Radiation can be alpha particles (stopped by paper or skin), beta particles (stopped by a thin sheet of aluminium), and gamma radiation or neutrons (stopped by metres of lead). These each have different effects on life forms, and taking this into account gives the theoretical dose if a human ingested or inhaled all the waste material, as opposed to the radioactivity, which is just the number of radioactive decays per second arising in the waste. This dose is called the radiotoxicity. The radiotoxicity of ITER is compared with fission (represented by a PWR) and fossil (represented by coal ash) power stations in the following figure:

ITER waste is increasingly less dangerous after 100 years than the total ash from a large coal-fired power plant, and around 50,000 times less than the waste from a PWR. For ITER, after 100 years, although the tonnage of waste is more than for fission, its vastly lower specific dose potential allows it to be packaged in a similar volume, in both cases with the extent of waste compaction being set by the ability to cool it during its remaining decay without human or machine involvement.