The views expressed about the role of nuclear power were passionate and reflected the highly emotional public controversy over the issue. Responses were about equally divided between those who believe that nuclear power should play a large role in future electric power production, and those who felt it is too dangerous to play any role at all. In addition, a sizable minority of respondents were conflicted, believing that nuclear power could play a role only if it met certain conditions (especially for operating safety and safe long-term waste storage), or as a transitional technology to a sustainable power generation technology for the future. Regardless of their position on nuclear power, most respondents agreed that alternatives to fossil fuels in the energy sector are needed, either because fossil fuels are nonrenewable resources that will be depleted at some point, or because carbon emissions from their use are unacceptably high.

This discussion comes at an opportune time. Nuclear power is receiving renewed interest because of its potential to reduce carbon emissions from the electric power sector, and thus help mitigate global climate change. Nuclear power currently supplies about 20 percent of U.S. electricity demand (compared to more than 70 percent in France), but no new generating plants have been ordered in the U.S. in the past 20 years due to a number of factors: high initial cost, safety and environmental concerns about possible releases of radioactive material during operation, potential vulnerability to terrorist attacks, proliferation concerns, and concerns about the transportation and long-term storage of radioactive wastes.

During the discussion summarized here, two major reports were announced that bear on the desirability of nuclear power. The Intergovernmental Panel on Climate Change (under U.N. auspices) released the Summary for Policymakers in its fourth report, entitled "Climate Change 2007: The Physical Science Basis," (www.ipcc.ch/SPM2feb07.pdf), which reinforced the contention that the observed warming of the atmosphere is due in large part to carbon emissions associated with human activity. The U.S. Nuclear Regulatory Commission, in releasing new security regulations, concluded that if attackers like those on September 11, 2001, flew a large aircraft into an American nuclear plant, "the likelihood of both damaging the reactor core and releasing radioactivity that could affect the public health and safety is low." (News release at www.nrc.gov/reading-rm/doc-collections/news/2007/07-012.html) These reports tended to support the desirability of carbon-free electricity generation options, including nuclear power, and may allay some of the concerns about its risks.

The experts who contributed initial opinions to this discussion were Patrick Moore, cofounder of Greenpeace, and Amory Lovins, CEO of the Rocky Mountain Institute. Moore noted that his initially negative views on nuclear power had changed over the years in light of the now-urgent need to reduce carbon emissions. In his view, nuclear power is the only viable option for large, baseload generation capacity in the future, and safety and environmental concerns are being adequately addressed. Lovins disagreed, arguing for a more distributed power generation model based on smaller generation facilities including renewables (e.g., wind), building-level combined-heat-and-power cogeneration, and improvements in energy efficiency. The two differed most notably on the issue of nuclear power costs, with Moore arguing that the average cost of producing nuclear energy in the U.S. is less than two cents per kilowatt hour and that this would decline with further advances in the technology. In contrast, Lovins asserted that nuclear energy is a "costlier market loser" to renewables if all costs - e.g., construction, financing costs, and subsidies to nuclear power - are included.

The respondents to the question could be divided into three groups: the ardent pro-nuclear group, the ardent anti-nuclear group, and a smaller minority of those who were conditional supporters or of mixed views. The following discussion summarizes the views expressed.