Thereafter, the United States government built a grossly oversized nuclear arsenal and never envisioned having to stop building it. Between 1944 and 1994, the Energy Department and its predecessors produced 99.5 metric tons of plutonium for use in an estimated 70,000 nuclear weapons. (An additional 11 tons were produced or acquired for research and development purposes.)

The perverse logic of the nuclear arms race reached a point of ultimate absurdity during the early Reagan presidency, when it was asserted that the winner of a nuclear war would be the one with the most weapons left afterward. Now, 80 percent of the US nuclear arsenal has been discarded, and the United States is still struggling with the strategic mistake of producing so much fissile material to begin with. Currently,  a total of 61.2 tons of plutonium is declared excess to the needs of the US government, of which 53.4 tons is designated for nuclear weapons.

The Energy Department faces the daunting task of geologically disposing of this huge cache of weapons-grade plutonium, so it can never be used again, while ensuring that its does not threaten the environment over a time period longer than human civilization has existed. Achieving safe plutonium disposal will be a multifaceted challenge requiring both long-term commitments and large financial investments at a time when nuclear modernization programs are also competing for federal funding. But arms control and disarmament will not progress as they should unless the excess plutonium problem is solved.

The scope of the problem. Safely ridding the nation of one of the world’s largest excess stockpiles of weapons-grade plutonium will be no minor feat. At issue is the US Energy Department’s 2016 decision to dilute and dispose of, all told, about 48.2 metric tons of plutonium, including 26.2 tons of components, known as “pits,” from several thousand dismantled thermonuclear warheads and 22 metric tons in other forms. These massive quantities of plutonium are destined for the Energy Department’s Waste Isolation Pilot Plant (WIPP), the nation’s only geologic burial site for radiological waste, dug into a deep-underground salt formation near Carlsbad New Mexico. WIPP was opened in 1999, originally for disposal of equipment, clothing, and soil contaminated with dilute amounts of transuranic elements, mostly plutonium, somewhere in the nation’s nuclear weapons complex. If one gram of soil contains as little as 1.587 micrograms of plutonium, the Energy Department is required by federal standards to geologically isolate it from the environment for at least 10,000 years at WIPP.

The site is not without its problems. In 2014, a drum burst open deep underground, shooting contamination to the surface and leading to a three-year closure of the facility that cost about $2 billion.

During the Cold War, the Energy Department facilities involved in weapons productions recovered residual plutonium from production processes—for example, the lathe turnings produced when spherical plutonium bomb cores were shaped—when the cost of doing so was less than the cost of making new plutonium in production reactors. After the downsizing of its Cold War warhead stockpile, in 1998 the Energy Department reclassified residues from the Rocky Flats Plant— some 3.5 metric tons of weapons-grade plutonium, or enough to fuel some 900 weapons—as waste that should also be disposed of in the WIPP. In fact, as of September 2019, more than two thirds of 5.36 metric tons of plutonium 239 placed  in the repository originally had been set aside to make bombs. An additional 5.29 metric tons of this residual plutonium is awaiting disposal, and amount that is separate from and above what is generally considered as excess fissile material from the weapons stockpile.

The government has not publicized the formidable challenges of protecting thousands of workers and members of the public during the process necessary to geologically dispose of this enormous stockpile of nuclear explosives. To put it bluntly, if not done with extreme care, plutonium is a waste-disposal nightmare. The isotope used in American nuclear weapons, plutonium 239, has a specific activity (that is, an amount of radiation produced per unit of mass) that is about 200,000 times greater than uranium 238’s, and plutonium 239 has a radioactive half-life of 24,110 years. Alpha particle emissions from plutonium and other transuranic elements are considered to be about 20 times more carcinogenic than x-rays.

Particles of plutonium less than a few microns in diameter can penetrate deep in the lungs and lymph nodes and also be deposited, via the bloodstream, in the liver, on bone surfaces, and in other organs. If inhaled, extremely small amounts can lead to cancer.

Stringent procedures—many involving large number of workers with specialized skills—are required to ensure that even small amounts of plutonium are properly processed. That processing often must be done by hand, using gloveboxes, to prevent the creation of a critical mass that initiates a nuclear chain reaction and the resulting highly dangerous bursts of energy and radioactivity. While technologies have existed for years to process plutonium, they come out of the Cold War era when safety was secondary to production. Over the years, dozens of workers around the world have been killed or seriously over- exposed from criticality accidents. Various safeguards—including a security system that carefully accounts for all plutonium and protects against theft and diversion—add another costly dimension to handling this nuclear explosive.

Plutonium production ends, but problems continue. Years before the collapse of the Soviet Union, the growing cost of plutonium production led to its gradual cessation. By the 1980s, half of every dollar spent to make plutonium at the aged Energy Department nuclear complex went for its burgeoning waste-management and environmental-restoration problems. By 1988, production costs compelled Energy Secretary John Herrington to declare: “We’re awash with plutonium. We have more than we need.”

By 1992, the United States had stopped making new nuclear weapons as the industrial base for producing them began to collapse; about 80 percent of the Energy Department’s sprawling nuclear weapons production complex was shuttered a few years later. This left behind a legacy of radioactive waste and human suffering, one that is still unfolding. The Energy Department’s recent baseline cost estimates for waste management and environmental remediation are about $435 billion for the two main plutonium production facilities, the Hanford Reservation in Washington and the Savannah River Site in South Carolina. The single largest portion of the entire US government’s environmental liability in 2019, including the Defense Department, is due to plutonium production at these two sites. In terms of the human legacy,  22,459 sick workers at three major plutonium and fabrication sites have been granted more than $4.2 billion in compensation and medical care…………….