The world is becoming awash in deadly plutonium, a result of nearly half a century of atomic weapons production and a 30-year buildup of waste products from the nuclear power industry. Plutonium is one of the most toxic substances on Earth, but increasingly no one knows what to do with it -- a dilemma underscored by the current debate among scientists over the safety of the government's long-planned nuclear waste disposal site in the Nevada desert.
The problem is going to be with us a long time. Plutonium has a half-life of 24,360 years, meaning that over that period of time exactly half the highly radiative substance will decay into the more stable element of lead. Thus it will be millions of years before today's plutonium wastes no longer pose a deadly hazad to humans and the environment.
Over the years, the U.S. government has proposed various alternatives for dealing with nuclear wastes. Early proposals for burning surplus plutonium in nuclear reactors were scrapped in 1977 out of fear that materials might be diverted into making nuclear bombs. In 1982 Congress began a search for burial sites, but political opposition from the states derailed that plan. In 1987, Yucca Mountain, an outcrop of volcanic ash in the Nevada desert, was chosen as the site for a single national nuclear dump. That plan was challenged recently by some government scientists, who warned the site could eventually blow up in a nuclear explosion fed by waste plutonium.
Yet alternatives to burial all entail serious drawbacks. Recycling plutonium in breeder reactors, which Japan has chosen to do, risks diversion of nuclear materials by rogue regimes or terrorist groups. Some have suggested firing surplus plutonium into space. But the high cost of launches and the possibility of accidents are formidable obstacles. Another idea is to bombard the stuff in particle accelerators to render it less toxic. That solution, however, relies on unproven technology that could take years to develop. Finally, plutonium could be dumped at sea in special containers. But such proposals evoke intense public opposition.
There is no easy way out of this dilemma because the most technically feasible alternatives are unacceptable politically, and the politically acceptable alternatives have serious technical flaws. Yet until the government comes up with a solution that satisfies both requirements, the deadly buildup will remain a ticking time bomb threatening the human species for generations to come.