The New Zealand government announced last week that the enormous jets of steam that roar out of the ground in the Wairakei district on North Island will be harnessed for a dual purpose. They will generate electricity, and also produce heavy water (deuterium oxide) for use as a moderator in the nuclear power reactors that Britain plans to start building soon (TIME, Feb. 28).
Deuterium (heavy hydrogen) is present in all water to the amount of 0.02%, and it can be separated with considerable difficulty by several processes, including fractional distillation. The geothermal plant, financed jointly by Britain and New Zealand, will...