In case of environmental contamination caused by the discharge of radioactive materials from reprocessing plant, worries on impact to human body and foodstuffs arise.
The Rokkasho Reprocessing Plant uses the best available domestic and foreign technologies to remove hazardous radioactive materials. Some radioactive material which has negligible impact on the human body, such as krypton-85, carbon-14 and tritium will be discharged into the air or the sea.
Although, these materials are also naturally existing radioactive materials and even if they are absorbed into the body, they will be readily excreted through normal metabolic processes.
Rice and other foodstuffs also contain naturally existing radioactive materials, such as potassium-40 and carbon-14. By taking them into our body through foodstuffs, we are exposed to radiation of around 0.3 millisieverts (the world average) annually.
Radioactive material released by the Rokkasho Reprocessing Plant are figured out to have some effects on the radiation levels of polished rice, fish and shellfish and the like. But these effects are estimated to represent a dose equivalent of around 0.022 millisieverts per annum, a level much lower then the statutory dose limit for individual public, 1 millisievert a year. This was confirmed by the National Safety Review.