Chapter 5 HAZARDS ASSOCIATED WITH THE DOME 5.1 Function of the Dome The function of the dome ig to prevent people from being to harmful amounts of radioactivity from the debris buried within. In practical terms, the dome will perform this function if it prevegts people from having direct physical access to the contents and if radionuclides exchanged betwcen the contents and the environment [do not create an unacceptable hazard. Before addressing how well the dome can be expected to fulfill these goals, certain background mater will be reviewed (sections 5.2-5.5). 5.2 Radionuclides in the Dome The total amount of transuranics contained within the dome i estimated to be 12.6 Ci (U.S. Gepartment of Energy 1979). Measu of the fission product content are not available, but a crude es of a maxiuum of 50 Ci of °"Sr and '*’Cs may be made using Atomic Energy Commission (1973) survey data. The average transuranic of the material within the dome can be calculated to be about 87 pCi/g, about twice the permissible soil content of 40 pCi/g for islands designated for residential use. The average value measured from the drilling samples from the dome was 21 pCi/g, but this ddes not take account of contaminated debris that was encased in concrete fin the center “donut hole” of the dome. Similarly, the average total value of **sr and '*’cs from the drilling samples was 29.3 pCi/g. In addition, an estimated 380 Ci of activation and fission p ucts Plus an unknown amount of transuranics are contained in the fall ck debris in the true crater bottom and in the water beneath the material in the dome (Air Force Weapons Laboratory TR-77-242 1978). Prior to *Direct radiation from the contents is net of concern. Radiation from the fission products cannot penetrate the dome cap and have falflives of less than 30 years. External exposures from transurani are not significant because the principle emissions are alpha partic ‘the external dose from the ?7*'Am gamma radiation is negligible f the concentrations present in the dome. 25