Determination of permissible exposure doses under the provisions of the regulations on installation and operation of marine reactors

The Ministry of Transportation defines on radioactive doses in the controlled area that exterior radioactive dose shall be 30 mili-rem for a week; concentrations of radioactive materials in the air or under the water shall be permissible concentrations otherwise specified for the employees multiplied by 0.75 in average for a week and that densities of radioactive materials on the surface of the things contaminated by such materials shall be 1/10 of permissible surface densities provided in a table attached. Permissible exposure dose outside the inspected surrounding area is 0.5 rem for a year. Permissible surface densities are included in a list attached. Permissible accumulative dose for the employees is the figure (unit rem) calculated by the formula D = 5(N-18), when D means permissible accumulative dose and N number of the age. Permissible exposure dose is 3 rem for 3 months for the employees, 1.5 rem for a year for persons other than the employees and 12 rem for the urgent work. Permissible densities for the employees, calculation of doses by interior exposure and permissible densities outside the inspected surrounding area are stipulated in detail with attached lists. (Okada, K.)