Development of a method for calculating the cost of the program for decommissioning of nuclear power plants. Prognosis of future costs for the authorities including the corresponding net present value. Analysis performed May 6-7 and June 8 2004

The aim of this report is to present a calculation of the authorities' total future costs in terms of their activities to monitor a safe and prudent decommission of the power plants, including the long term storage of the used fuel. An assessment of the inherent uncertainty in this estimate is also made. The study forms an integrated part of the total monitoring into the financial assessment of the whole programme of decommissioning and demolition of the Swedish nuclear power plants that continuously is made by SKI. Hence, the estimate is presented with the additional function of supporting SKI's annual calculations of fees and contingencies in accordance with the Swedish Finance Act. Main result The expected Net Present Value of the authorities' costs as at January 2004 price level have consequently been estimated as follows: Mean Value (M): 2303 MSEK Standard deviation (S): 538 MSEK 8 This result tallies with the corresponding prognoses for the last two years. An additional clarification of a number of key figures resulted in some reduction of the total Net Present Value. By way of supplement to this main result, the undiscounted costs have been estimated (calculation 2). Besides, a tentative estimate has also been made by incorporating the official view on the future development on real rate of return in a long time perspective (calculation 3). The uncertainty of the result is significant in terms of the final budget figures and of the scale of the supplementary amounts in those situations where the budgets must be prudent and conservative. There may be a potential for further reduction of the current uncertainty in that the greatest causes of uncertainty now have been identified and ranked in order of priority. The greatest causes of uncertainty are set out in the table below. No. Cause of uncertainty Uncertainty group 1 Priority 2 1 Correction allowing for the uncertainty of the real interest rate N 55 % 2 Productivity E2 8 % 3 Uncertainty in the current base values 6 % 4 Analysis-specific uncertainty Y 6 % 5 Base value of other organisations' undiscounted costs 4 % 6 Relations with SKB and authorities C 4 % 7 Classification rules for waste L 4 % 8 Political, economic and social factors A 3 % 9 Organisation and management B 2 % 10 Base value, undiscounted interfaces 2 % 1The main objectives of the study to present a transparent and robust probabilistic estimate and an equivalent report have been achieved. Furthermore, the analysis process has also contributed to the building up of a systematic knowledge base in this area by means of regular meetings with the expert group since the spring of 2002. It is also satisfying that the mean value of the estimates remains stable and that there has been a degree of reduction of the uncertainty. Integration with SKB's procurement of bases for charges and contingencies The mean derived from this analysis can correctly be added to the mean of the remaining discounted costs, i.e. mean values of the 40 main cost items which are set out in SKB's 'PLAN 2004'. A somewhat more accurate processing of the uncertainty is, however, encumbered with a number of principal methodological difficulties. These minor obstacles are dealt with in some depth in section 7.3. Three days of analysis proved to be sufficient for an examination of all the relevant specifications, discussions and more detailed evaluations. It was ascertained that, with improved preparation, the time needed for future analyses could be reduced to two days. This is important, as the process requires between 10 a nd 15 highly qualified individuals to be assembled to perform the analyses