not fissile because it contains 99.3% of U-238 and only 0.7% of U-235. Legacy waste Due to historic activities typically related to the radium industry, uranium mining, and military programs, numerous sites contain or are contaminated with radioactivity. In the United States alone, the Department of Energy states there are "millions of gallons of radioactive waste" as well as "thousands of tons of spent nuclear fuel and material" and also "huge quantities of contaminated soil and water." Despite copious quantities of waste, the DOE has stated a goal of cleaning all presently contaminated sites successfully by 2025. The Fernald, Ohio site for example had "31 million pounds of uranium product", "2.5 billion pounds of waste", "2.75 million cubic yards of contaminated soil and debris", and a "223 acre portion of the underlying Great Miami Aquifer had uranium levels above drinking standards." The United States has at least 108 sites designated as areas that are contaminated and unusable, sometimes many thousands of acres. DOE wishes to clean or mitigate many or all by 2025, using the recently developed method of geomelting, however the task can be difficult and it acknowledges that some may never be completely remediated. In just one of these 108 larger designations, Oak Ridge National Laboratory, there were for example at least "167 known contaminant release sites" in one of the three subdivisions of the site. Some of the U.S. sites were smaller in nature, however, cleanup issues were simpler to address, and DOE has successfully completed cleanup, or at least closure, of several sites. Medicine Radioactive medical waste tends to contain beta particle and gamma ray emitters. It can be divided into two main classes. In diagnostic nuclear medicine a number of short-lived gamma emitters such as technetium-99m are used. Many of these can be disposed of by leaving it to decay for a short time before disposal as normal waste. Other isotopes used in medicine, with half-lives in parentheses, include: Y-90, used for treating lymphoma (2.7 days) I-131, used for thyroid function tests and for treating thyroid cancer (8.0 days) Sr-89, used for treating bone cancer, intravenous injection (52 days) Ir-192, used for brachytherapy (74 days) Co-60, used for brachytherapy and external radiotherapy (5.3 years) Cs-137, used for brachytherapy and external radiotherapy (30 years) Tc-99, product of the decay of Technetium-99m (221,000 years) Industry Industrial source waste can contain alpha, beta, neutron or gamma emitters. Gamma