Editing Technetium (section)

===Fission waste product===
In contrast to the rare natural occurrence, bulk quantities of technetium-99 are produced each year from [[spent nuclear fuel|spent nuclear fuel rods]], which contain various fission products. The fission of a gram of [[uranium-235]] in [[nuclear reactor]]s yields 27&nbsp;mg of technetium-99, giving technetium a [[fission product yield]] of 6.1%.<ref name="enc" /> Other [[fissile]] isotopes produce similar yields of technetium, such as 4.9% from [[uranium-233]] and 6.21% from [[plutonium-239]].{{sfn|Schwochau|2000|pp=374–404}} An estimated 49,000&nbsp;T[[Becquerel|Bq]] (78&nbsp;[[tonne|metric tons]]) of technetium was produced in nuclear reactors between 1983 and 1994, by far the dominant source of terrestrial technetium.<ref name=yoshihara>
{{cite book
 |last=Yoshihara   |first=K.
 |date=1996
 |chapter=Technetium in the environment
 |editor1-last=Yoshihara  |editor1-first=K.
 |editor2-last=Omori      |editor2-first=T.
 |title=Technetium and Rhenium: Their chemistry and its applications
 |series=Topics in Current Chemistry |volume=176
 |publisher=Springer-Verlag
 |location=Berlin / Heidelberg, DE
 |isbn=978-3-540-59469-7
 |doi=10.1007/3-540-59469-8_2
 |pages=17–35
}}
</ref><ref name=leon/>
Only a fraction of the production is used commercially.{{efn|
{{As of|2005}}, technetium-99 in the form of [[ammonium pertechnetate]] is available to holders of an [[Oak Ridge National Laboratory]] permit.{{sfn|Hammond|2004|p={{page needed|date=June 2021}}}}
}}

Technetium-99 is produced by the [[nuclear fission]] of both uranium-235 and plutonium-239. It is therefore present in [[radioactive waste]] and in the [[nuclear fallout]] of [[nuclear weapon|fission bomb]] explosions. Its decay, measured in [[becquerel]]s per amount of spent fuel, is the dominant contributor to nuclear waste radioactivity after about {{nobr|{{10^|4}}~{{10^|6}} years}} after the creation of the nuclear waste.<ref name=yoshihara/> From 1945–1994, an estimated 160&nbsp;T[[Becquerel|Bq]] (about 250&nbsp;kg) of technetium-99 was released into the environment during atmospheric [[nuclear test]]s.<ref name=yoshihara/><ref>
{{cite book
 |last1=Desmet     |first1=G.
 |last2=Myttenaere |first2=C.
 |date=1986
 |title=Technetium in the Environment
 |publisher=Springer
 |isbn=978-0-85334-421-6
 |page=69
 |url=https://books.google.com/books?id=QLHr-UYWoo8C&pg=PA69
}}
</ref>
The amount of technetium-99 from nuclear reactors released into the environment up to 1986 is on the order of 1000&nbsp;TBq (about 1600&nbsp;kg), primarily by [[nuclear fuel reprocessing]]; most of this was discharged into the sea. Reprocessing methods have reduced emissions since then, but as of 2005 the primary release of technetium-99 into the environment is by the [[Sellafield]] plant, which released an estimated 550&nbsp;TBq (about 900&nbsp;kg) from 1995 to 1999 into the [[Irish Sea]].<ref name=leon>
{{cite journal
 |last=Garcia-Leon  |first=M.
 |date=2005
 |title={{sup|99}}Tc in the environment: Sources, distribution, and methods
 |journal=Journal of Nuclear and Radiochemical Sciences
 |volume=6 |issue=3 |pages=253–259
 |doi=10.14494/jnrs2000.6.3_253 |doi-access=free
 |url=http://www.radiochem.org/paper/JN63/jn6326.pdf
}}
</ref> 
From 2000 onwards the amount has been limited by regulation to 90&nbsp;TBq (about 140&nbsp;kg) per year.<ref>
{{cite journal
 |first=K.  |last=Tagami
 |date=2000
 |title=Technetium-99 behaviour in the terrestrial environment — field observations and radiotracer experiments
 |journal=Journal of Nuclear and Radiochemical Sciences
 |volume=4  |pages=A1–A8
 |doi=10.14494/jnrs2000.4.a1  |doi-access=free
 |url=https://www.jstage.jst.go.jp/article/jnrs2000/4/1/4_1_A1/_pdf
}}
</ref>
Discharge of technetium into the sea resulted in contamination of some seafood with minuscule quantities of this element. For example, [[European lobster]] and fish from west [[Cumbria]] contain about 1&nbsp;Bq/kg of technetium.<ref>
{{cite book
 |url=https://books.google.com/books?id=zVmdln2pJxUC&pg=PA403
 |page=403
 |title=Mineral Components in Foods
 |last1=Szefer |first1=P.
 |last2=Nriagu |first2=J.O.
 |publisher=CRC Press
 |date=2006
 |isbn=978-0-8493-2234-1
}}
</ref><ref>
{{cite journal
 |first1=J.D. |last1=Harrison
 |first2=A.   |last2=Phipps
 |date=2001
 |title=Gut transfer and doses from environmental technetium
 |journal=Journal of Radiological Protection
 |volume=21  |issue=1  |pages=9–11
 |doi=10.1088/0952-4746/21/1/004
 |bibcode=2001JRP....21....9H
 |pmid=11281541   |s2cid=250752077
}}
</ref>{{efn|
The [[anaerobic organism|anaerobic]], [[endospore|spore]]-forming [[bacteria]] in the ''[[Clostridium]]'' [[genus]] are able to reduce Tc(VII) to Tc(IV). ''Clostridia'' bacteria play a role in reducing iron, [[manganese]], and uranium, thereby affecting these elements' solubility in soil and sediments. Their ability to reduce technetium may determine a large part of mobility of technetium in industrial wastes and other subsurface environments.<ref>
{{cite journal
 |last1=Francis |first1=A.J.
 |last2=Dodge   |first2=C.J.
 |last3=Meinken |first3=G.E.
 |date=2002 
 |title=Biotransformation of pertechnetate by ''Clostridia''
 |journal=Radiochimica Acta
 |volume=90 |issue=9–11 |pages=791–797
 |doi= 10.1524/ract.2002.90.9-11_2002.791
 |s2cid=83759112
 |url=https://zenodo.org/record/1236279
}}
</ref>
}}