Nuclide reduction module for the purpose the Information and Documentation Centre (IDC) for nuclear accidents emergency planning

Within the framework of a national program on emergency response planning and preparedness for a nuclear accident (PKOB) an Information and Documentation Centre (IDC) has been developed at RIVM. This IDC projects for instance the effective dose equivalent due to radionuclides that may be released during a nuclear accident. One of the tools in use is an air transport model. To direct the attention to the most significant radionuclides, as far as the dose to the population due to internal radiation after inhalation and external radiation is concerned, and to speed up calculations, a method was developed to sort the 54 most important radionuclides from a nuclear release according to their contribution to dose. This method has been turned into a spreadsheet model and is described in this report. Also an outline is given that was used for the implementation of the method within the IDC on a HP-9000/370 computer. Using the 'radionuclide reduction' method it can be shown that for source terms of different types of accidents a quite different set of radionuclides is of importance for the effective dose equivalent during or after the passage of a cloud of radioactive material. Another result is that on the short term (upto a few days) the set of seven radionuclides that contribute the most to the effective dose equivalent (during or after passage) is not significantly influenced by the transport time of the cloud of radioactive material to the location where the dose is delivered. 2 tabs., 4 appendices, 11 refs