The radioactivity standards programme of the National Bureau of Standards

From nuclear data tables, such as those compiled by the Oak Ridge Nuclear Data Project, the absorbed dose to a homogeneous medium can be calculated from given values of the mean energy per decay, expressed in gram rad per microcurie hour. To make any of these calculations the activities of the various components of radioactive effluents or of the administered radiopharmaceuticals must be known. For more than ten years the Radioactivity Section of the National Bureau of Standards has been devoting a very considerable part of its effort to the production of radioactivity standards that are needed in environmental and nuclear-medicine measurements. Such standards are also being produced in appropriate environmental matrices and the latest available nuclear-decay data, often produced in the Radioactivity Section, is also supplied. Traceability to the International and National Radioactivity Measurements Systems is discussed. (author)