Chapter 5 HAZARDS ASSCCIATED WITH THE DOME §.1 Punction of the Dome . The function of the dome is to prevent people from being exposed to harmful.amounts of radioactivity from the debris buried within. In Practical terms, the dome will perform this function if it prevents people from having direct physical access to the contents and if any radionuclides exchanged between the contents and the environment do not Before addressing how well the dome create an unacceptable hazard. ean be expected to fulfill these goals, certain background material will be reviewed (sections 5.2-5.5). 5.2 Radionuclides in the Bome ‘The total amount of transuranics contained within the dome is estimated to be 12.6 Ci (U.S. Department of Energy 1979). Measurements of the fission product content are not available, but a crude estimate of a maximum of 50 Ci of °*Sr and '*’Cs may be made using Atomic Energy Commission (1973) survey data. The average transuranic content 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 does net take account of contaminated debris that was encased in concrete in 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 products Plus an unknown amount of transuranics are contained in the fall-back 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 not of concern. ° Radiation from the fission products cannot penetrate the dome cap and have halflives of less than 30 years. External exposures from transuranics are not significant because the principle emissions are alpha particles; the external dose from the **'am gamma radiation is negligible for the concentrations present in the dome. 25 206 4340