[en] Off-site doses to the public were evaluated based on LLDs(Lower Limits of Detection) of radionuclides stated in NUREG-1301. It was found that off-site doses corresponding to LLDs of NUREG-1301 are not so conservatively low, compared with dose constraints stated in the MOST Notice No. 98-12. Thus, it is required that all mesured data at the release points should be used to calculate the amount of radionuclides released into the environment as well as the doses to the public, regardless of LLDs of the radionuclides. For the gaseous effluents, LLDs for the tritium, strontium, and gross-alpha radioactivity were shown to be relatively high in terms of the effluent monitoring for the prevention of environmental impacts. For the liquid effluents, LLDs for the radio-iodine and ⁵⁵Fe were shown to be relatively high. Optimal LLDs of the radionuclides mentioned above were established based on the ICRP-60 recommendations by setting 10% of dose constraints stated in the MOST notice No. 98-12 as the guideline for the establishments of the LLDs. In addition, it was found out that the amount of ⁵⁵Fe released into the ocean should be measured periodically based on the frequency of NUREG-1301 and off-site doses should be evaluated using these measured data. With regard to the containment purge, LLDs of grab samples were shown to be inappropriate as the basis for the assessment of the amount of radionuclides released into the environment since their values stated in NUREG-1301 are high in terms of the effluent monitoring for the prevention of environmental impacts. For the gaseous effluents, the effluent monitoring of continuous paths to the environs using grab sampling and LLDs for grab samples were shown to be inappropriate in terms of the effluent monitoring for the prevention of environmental impacts