Annual report on the activities of health physics in JAERI in 2004. April 1, 2004 - March 31, 2005

This annual report describes the activities of radiation protection practices and research in JAERI in the 2004 fiscal year. The report covers environmental monitoring around the facilities, radiation protection of workplace and workers, individual monitoring, maintenance of monitoring instruments, and development of radiation protection technologies, which were performed at the establishments of Tokai, Naka, Takasaki, Oarai, Kansai and Mutsu of JAERI. The report also includes the research activities on radiation risk studies, radiation dosimetry studies and radiation measurement technology development, which were carried out by four research laboratories of the Department of Health Physics in the Tokai Research Establishment. There were no occupational exposures exceeding the prescribed dose limits. No effluent releases were recorded, which exceeded the prescribed limits for the amount and concentration of radioactivity of gaseous release and liquid waste. As for the research activities, studies were conducted focusing mainly on the following themes: study on computer simulation of primary radiation effects on DNA, development of mathematical carcinogenic model, development of monitoring methods of airborne radioactive materials produced in high-energy proton accelerator facilities, study on dosimetry for high energy radiation, development of nuclear decay database for dose evaluation, and establishment of calibration fields for monoenergetic neutrons. (author)