Nuclear reactors generate 19 percent of the electricity in the U.S., and this process generates high-level radioactive waste in the form of uranium oxide or mixed oxide fuels. Approximately 1000 m3 (6200 bbl) of high-level waste is produced each year from commercial reactors in the U.S., and additional material is generated by military operations. Europe is also heavily invested in nuclear power (e.g. more than three-fourths of the electricity in France is generated by nuclear reactors), and other countries worldwide have started to aggressively pursue nuclear energy to power their growing economies.
As a result, the current rate of nuclear waste generation is approximately 10,000 m3/yr, and the amount of radioactive waste being generated worldwide is expected to increase significantly. Yet, there are no safe, reliable ways to dispose of nuclear waste on site, that is, at the source of the waste's generation. This waste includes but is not limited to spent nuclear fuel from nuclear reactors, high-level waste from the reprocessing of spent nuclear fuel, transuranic waste mainly from defense programs, and uranium mill tailings from the mining and milling of uranium ore. High-level nuclear waste is currently stored at the reactor where it was generated. The only serious options for disposal being considered are to place the waste in low permeability geologic formations, like tight rock or clay. The current approach for disposal of radioactive waste is not without problems. Congress has mandated a 10,000-year period of isolation, but it is difficult to guarantee that waste at the shallow depths of current repositories will remain isolated from the biosphere, or human intervention, for even a fraction of this time.
Yucca Mountain, a 300-m-deep facility near Las Vegas, is the only U.S. option for high-level waste disposal. This facility has been scrutinized for 20 years, and even after a $50B expenditure the earliest it could open is 2017. Considerable political opposition by Congress, the state of Nevada and others may delay opening even further. For example, Congress did not provide any funding for development of the site in the 2011 federal budget. Significant uncertainty exists about the feasibility of waste placed at a depth of 300 m remaining isolated from the biosphere for 10,000 years, and this uncertainty is the basis for much of the opposition to Yucca Mountain. Even if Yucca Mountain does open, all its capacity has been allocated and options for additional capacity are being considered.
The politics involved in finding permanent disposal sites is, at best, difficult and, at worst, intractable. Because the waste remains radioactive for a very long time, no one wants this waste traveling through their “backyard” on its way to a permanent disposal site or in their “backyard” as the disposal site. As politicians and the public continue to debate the issue, the waste remains temporarily stored on site in ways that are arguably far less safe than any proposed permanent disposal solution. For example, nuclear reactors temporarily store the waste on site in water pools. The devastating earthquake and tsunami in northeast Japan, which knocked out power sources and cooling systems at Tokyo Electric Power Cots Fukushima Daiichi plant, demonstrates how tenuous and potentially dangerous this storage practice really is.
Therefore, a need exits for a safe, reliable method of disposing nuclear waste on site and one that could achieve the 10,000 year period of isolation required by Congress and sought by other countries.
USPTO Backgrounds
USPTO Backgrounds