Tritium level near Fukushima plant well below Tepco standards

Nuclear energy provides almost 20 percent of the U.S. electricity supply. Advocates have called for an expanded role for nuclear as an emissions-free fuel source. But the economics of building new reactors are daunting. In addition, lingering safety concerns are an institutionalized part of the calculation of nuclear regulation, and highly radioactive nuclear waste remains a can that public officials have been inclined to kick down the road. The Energy Information Administration projects a sharp decline in nuclear power generation over the next decade, as new nuclear plants — two are planned — are more than offset by anticipated retirements of several operating reactors.

While the United States and other industrial nations have made significant strides since the 1970s in the control of conventional pollution from energy production, growing understanding of the impact of carbon dioxide and other emissions on the world’s climate has increased the urgency of converting the world’s economy to renewable, less-polluting energy sources. Worldwide efforts to reduce greenhouse gas emissions had been complicated by rapid economic growth in countries such as China and India, growth literally fueled by coal and petroleum products. Those countries have more recently joined the global effort to address climate change, and the United States —which abruptly reversed direction under the Trump administration — has made clear its intention under President Biden to rejoin the global community on the issue.