The purpose of this work was to calculate the relative contributions to effective radiation dose or effective radiation dose rate from fission products of U-235. These calculations have been carried out for different types of exposure. This means that in a real event several cases of exposure can occur, i.e. a person can simultaneously be exposed both from the environment via radioactivity in the surrounding air and from a ground cover as well as via internal exposure via inhalation and oral intake. The calculations have been carried out using a software-based calculation tool that calculates which fission products are formed during the fission of U-235. Furthermore, the tool can calculate how the specific radioactivity of these changes, as well as which decay products are formed, over time. These results have then been used to calculate, together with dose factors taken from reference literature, the total effective radiation dose or radiation dose rate for all fission products at assumed times and exposure cases. The assumed times of exposure range from 1 minute up to 70 years after explosion. The work is based on the assumption that changes over time in nuclide composition and activity are only affected by radioactive decay and growth through the formation of decay products. This means that other factors that can change the nuclide composition depending on the substances' chemical and physical form or the influence of meteorology are not included in this work. The exposure cases chosen are for external exposure: homogeneous distribution of radioactivity in the surrounding air, surface coating on soil, and soil coating where the fallout is homogeneously distributed in the top centimeter of the soil layer. For internal exposure, two cases have been chosen: inhalation and oral intake. The result of the calculations can then be used to select one or more radioactive nuclides that are of interest at a given time and exposure case. There are several reasons for such selections. It may be that the nuclide or nuclides that contribute most to effective radiation dose or radiation dose rate are of interest. Such needs can e.g. be generated by how the current radiation protection should be prioritized and designed. Furthermore, the reason for the selection criterion may be based on which nuclides are best suited for gamma spectrometric analyses. The results can also be used to calculate which effective radiation doses or radiation dose rates have been present from a historical perspective. This is done by using the radioactivity of a long-lived nuclide and then correcting for decay and redistribution in the environment. The redistribution over time can be due to, for example, water runoff, penetration into land or agriculture and animal husbandry. All in all, the effective radiation dose or radiation dose rate obtained from the fission products during fission of U-235 at a given time and exposure case can be calculated given the assumptions made. I.e. if a specific nuclide is quantified and its dose factor for the current exposure case is taken from a reference, its individual contribution to effective radiation dose can be calculated. Then the total effective radiation dose or radiation dose rate can be calculated based on its relative contribution. The results are presented in tabular form for each exposure case and at the selected times after the explosion. Finally, three examples of calculation that can be carried out using the attached results are given. Two of these are based on calculations of the estimated total dose rate for two exposure cases where all radioactivity is homogeneously distributed on, or in the top centimeter of the ground surface. The calculation example is based on a fictitious measurement of ground deposition 1 year after the explosion, which is assumed to give a ground coating of 105 Bq/m2 of Cs-137. This then results in a total dose rate of 2.1 Sv/h 1 hour after explosion if the deposition is on the ground surface. If the corresponding calculation is made for the time 1 year after the explosion, it gives a dose rate of 50 nSv/h if the deposition is homogenous distributed in the top centimeter of the ground surface. The final example is based on the calculation of an estimated soil concentration of Cs-137 that should be present if a dose rate measurement is carried out in the field yielding a measurement result of 1 Sv/h. According to the stated conditions, this corresponds to an estimated ground concentration of 40 000 Bq/m2 Cs-137 on the surface.