Another US NRC deadline is upon us for 24 March 2015: https://www.federalregister.gov/articles/2014/11/20/2014-27519/radiation-protection The following article by Dr. Ian Fairlie should prove helpful for the question about embryo-fetal exposure to radiation, dose assessment, and more. Dr. Fairlie has a degree in radiation biology and his doctoral studies concerned the radiological hazards of nuclear fuel reprocessing. [1] His research was instrumental in shutting down Quebec’s nuclear power station. His 2014 article, related to the one below, is discussed here: http://www.ianfairlie.org/news/childhood-leukemias-near-nuclear-power-stations-new-article/ Highlight-Underline added. Original document here: http://www.ehjournal.net/content/8/1/43

Note that many nuclear reactors do “Batch releases” of radionuclides into the air, and/or water, multiple times per year and not only when the fuel is changed. That is, some reactors leak constantly and some hold back the leaks until some of the short-lived radionuclides have become less radioactive or non-radioactive. Then they release the remaining longer and long-lived radionuclides all at once as “effluent”. Dilution…