AbstractAn empirical study, financed by the Swedish Radiation Authority (SSI), on perception of time, time periods, and responsibilities related to the final repository for spent nuclear fuel was conducted in 2002. Citizens of the Oskarshamn and Östhammar municipalities (N=1,501) responded to a postal questionnaire regarding their participation in site‐specific investigations for the building of the Swedish repository, administered by the Swedish Nuclear Fuel and Waste Management Co (SKB). Approximately 41% of the sampled citizens responded to an eight‐page questionnaire, which included tasks of time estimates of specified historic events (e.g., when the first human landed on the moon, the development of Homo sapiens) and possible future events (e.g., a new glacial ice period, a radiation leakage from canisters in the repository). Some questions asked for risk estimations in relation to the repository, i.e., for oneself and for others in the community. Other questions inquired about perceptions of risks and responsibilities related to future generations. SSI was especially interested in the respondents' ratings of the importance of the authority's reviews of SKB's research programs for specified time periods, i.e., during operation, in a thousand years, ten thousand years, hundred thousand years, and up to a million years. The overall results showed rather restricted time horizons among the respondents. Risk estimations relating to nuclear wastes were not extremely high, and as usual the risk to others rated higher than the risk to oneself. Regarding the importance of SSI's review of SKB's research programs, people emphasized the importance of such reviews in the near future in contrast to the distant future, i.e., while under operation and up to 1,000 years, rather than for the longer time periods of relevance for the reviews. People also perceived the consequences to be much more severe in the shorter time perspectives than in the longer ones, given a leakage from the canisters in the repository. The importance of future generations' life situations was reported as high, and perceived to be of greater importance to oneself than to others. The construction of a safe final repository for spent nuclear fuel ranked the highest on a list of topics when respondents indicated the responsibilities of current generations. Ranked second and third were the items “to fight criminality” and “to give children and youth a good education.” The responsibility for depositing spent nuclear fuel in a reassuring manner was mainly attached to the entrepreneur, SKB, closely followed by the authorities (SSI and the Swedish Nuclear Safety Authority, SKI). The discussion focuses on the apparent paradox involving participants rather short time horizons, especially into the future, decreasing risk estimates across long time perspectives, and very high ratings regarding current generations' responsibilities for the life situations of future generations.