Editing Technetium (section)

===Waste disposal===
The long half-life of technetium-99 and its potential to form [[anionic]] species creates a major concern for long-term [[High-level radioactive waste management|disposal of radioactive waste]]. Many of the processes designed to remove fission products in reprocessing plants aim at [[cationic]] species such as [[caesium]] (e.g., [[caesium-137]]) and [[strontium]] (e.g., [[strontium-90]]). Hence the pertechnetate escapes through those processes. Current disposal options favor [[geological repository|burial]] in continental, geologically stable rock. The primary danger with such practice is the likelihood that the waste will contact water, which could leach radioactive contamination into the environment. The anionic pertechnetate and [[iodide]] tend not to adsorb into the surfaces of minerals, and are likely to be washed away. By comparison [[plutonium]], [[uranium]], and [[caesium]] tend to bind to soil particles. Technetium could be immobilized by some environments, such as microbial activity in lake bottom sediments,<ref>{{cite journal | last1 = German | first1 = Konstantin E. | last2 = Firsova | first2 = E. V. | title = Bioaccumulation of Tc, Pu, and Np on Bottom Sediments in Two Types of Freshwater Lakes of the Moscow Oblast | journal = Radiochemistry | volume = 45 | pages = 250–256 | date = 2003 | issue = 6 | doi = 10.1023/A:1026008108860 | last3 = Peretrukhin | first3 = V. F. | last4 = Khizhnyak | first4 = T. V. | last5 = Simonoff | first5 = M. | bibcode = 2003Radch..45..250G | s2cid = 55030255 }}</ref> and the [[environmental chemistry]] of technetium is an area of active research.<ref>{{cite book|url=https://books.google.com/books?id=eEeJbur_je0C&pg=PA147|page=147|title=Radioactivity in the terrestrial environment|last=Shaw |first=G. |publisher=Elsevier |date=2007 |isbn=978-0-08-043872-6}}</ref>

An alternative disposal method, [[Nuclear transmutation|transmutation]], has been demonstrated at [[CERN]] for technetium-99. In this process, the technetium (technetium-99 as a metal target) is bombarded with [[neutron]]s to form the short-lived technetium-100 (half-life = 16&nbsp;seconds) which decays by beta decay to stable [[ruthenium]]-100. If recovery of usable ruthenium is a goal, an extremely pure technetium target is needed; if small traces of the [[minor actinide]]s such as [[americium]] and [[curium]] are present in the target, they are likely to undergo fission and form more [[fission product]]s which increase the radioactivity of the irradiated target. The formation of ruthenium-106 (half-life 374&nbsp;days) from the 'fresh fission' is likely to increase the activity of the final ruthenium metal, which will then require a longer cooling time after irradiation before the ruthenium can be used.<ref>{{cite book|url=http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=2000XT88.txt|title=Alternative disposal concepts for high-level and transuranic radioactive waste disposal|publisher=US Environmental Protection Agency|date=1979|author=Altomare, P|last2=Bernardi}}</ref>

The actual separation of technetium-99 from spent nuclear fuel is a long process. During [[nuclear reprocessing|fuel reprocessing]], it comes out as a component of the highly radioactive waste liquid. After sitting for several years, the radioactivity reduces to a level where extraction of the long-lived isotopes, including technetium-99, becomes feasible. A series of chemical processes yields technetium-99 metal of high<!--isotopic and chemical?--> purity.{{sfn|Schwochau|2000|pp=87–96}}