Japan on Thursday marked the beginning of a decadeslong process to release treated water, currently stored in tanks at the crippled Fukushima nuclear power plant, into the ocean. Through a process known as the Advanced Liquid Processing System (ALPS), nearly 1.34 million metric tons of water in about 1,000 storage tanks on the Fukushima site will be treated to remove almost all radiation except tritium, and then discharged.

The International Atomic Energy Agency, the Japanese government and many nuclear experts say this process is safe and consistent with what other countries are doing. Nonetheless, constant on-site monitoring over the next 30 to 40 years will be required.

Contaminated water