About 77 million gallons of military nuclear waste in liquid form was stored in steel tanks, mostly in South Carolina, Washington, and Idaho.

Highly radioactive spent fuel rods were stored in pools of water at reactor sites, but many utilities were running out of storage space.

The Act also called for developing plans by 1985 to build monitored retrievable storage (MRS) facilities, where wastes could be kept for 50 to 100 years or more and then be removed for permanent disposal or for reprocessing.

Congress assigned responsibility to the U.S. Department of Energy (DOE) to site, construct, operate, and close a repository for the disposal of spent nuclear fuel and high-level radioactive waste.

The Act required the national government to take ownership of all nuclear waste or spent fuel at the reactor site, transport it to the repository, and thereafter be responsible for its containment.

[5] The Act authorized DOE to provide up to 1,900 metric tons of temporary storage capacity for spent fuel from civilian nuclear reactors.

In March 1987, after more than a year of legal action in the federal courts, the DOE submitted its final proposal to Congress for the construction of a MRS facility at the Clinch River Breeder Reactor Site in Oak Ridge, Tennessee.

Following considerable public pressure and threat of veto by the Governor of Tennessee, the 1987 amendments to the NWPA "annulled and revoked" MRS plans for all of the proposed sites.

[7] The Act required DOE to consult closely throughout the site selection process with states or Indian tribes that might be affected by the location of a waste facility, and allowed a state (governor or legislature) or Indian tribe to veto a federal decision to place within its borders a waste repository or temporary storage facility holding 300 tons or more of spent fuel, but provided that the veto could be overruled by a vote of both houses of Congress.

The Act authorized impact assistance payments to states or Indian tribes to offset any costs resulting from location of a waste facility within their borders.

[8] However (according to the Draft Report by the Blue Ribbon Commission on America's Nuclear Future), actions by both Congress and the Executive Branch have made the money in the fund effectively inaccessible to serving its original purpose.

[13] In 2004, the U.S. Court of Appeals for the District of Columbia Circuit upheld a challenge by Nevada, ruling that EPA's 10,000-year compliance period for isolation of radioactive waste was not consistent with National Academy of Sciences (NAS) recommendations and was too short.

[16] By limiting the compliance time to 10,000 years, EPA did not respect a statutory requirement that it develop standards consistent with NAS recommendations.

"[18] On March 5, 2009, Energy Secretary Steven Chu told a Senate hearing the Yucca Mountain site is no longer viewed as an option for storing reactor waste.

[citation needed] In late February 2010, multiple lawsuits were proposed and/or being filed in various federal courts across the country to contest the legality of Chu's direction to DOE to withdraw the license application.

[citation needed] Because some radioactive species have half-lives longer than one million years, even very low container leakage and radionuclide migration rates must be taken into account.

Enrico Fermi described an alternative solution: Consume all actinides in fast neutron reactors, leaving only fission products requiring special custody for less than 300 years.

Previous experiences sealing mine tunnels and shafts have not been entirely successful, especially where there is any hydraulic pressure from groundwater infiltration into disturbed underground geologic structures.

Historical attempts to seal smaller bore holes created during exploration for oil, gas, and water are notorious for their high failure rates, often in periods less than 50 years.