Editing Fusion power (section)

=== Radioactive waste ===
{{See also|Radioactive waste}}

Fusion reactors create far less radioactive material than fission reactors. Further, the material it creates is less damaging biologically, and the radioactivity dissipates within a time period that is well within existing engineering capabilities for safe long-term waste storage.<ref name="demonstration">{{Cite journal |last1=Gonzalez de Vicente |first1=Sehila M. |last2=Smith |first2=Nicholas A. |last3=El-Guebaly |first3=Laila |last4=Ciattaglia |first4=Sergio |last5=Di Pace |first5=Luigi |last6=Gilbert |first6=Mark |last7=Mandoki |first7=Robert |last8=Rosanvallon |first8=Sandrine |last9=Someya |first9=Youji |last10=Tobita |first10=Kenji |last11=Torcy |first11=David |date=August 1, 2022 |title=Overview on the management of radioactive waste from fusion facilities: ITER, demonstration machines and power plants |journal=Nuclear Fusion |volume=62 |issue=8 |pages=085001 |doi=10.1088/1741-4326/ac62f7 |bibcode=2022NucFu..62h5001G |s2cid=247920590 |issn=0029-5515|doi-access=free }}</ref> In specific terms, except in the case of [[aneutronic fusion]],<ref>{{Cite book|last1=Harms|first1=A. A.|url=https://books.google.com/books?id=DD0sZgutqowC&pg=PA8|title=Principles of Fusion Energy: An Introduction to Fusion Energy for Students of Science and Engineering|last2=Schoepf|first2=Klaus F.|last3=Kingdon|first3=David Ross|date=2000|publisher=World Scientific|isbn=978-9812380333|language=en}}</ref><ref>{{Cite journal|last1=Carayannis|first1=Elias G.|last2=Draper|first2=John|last3=Iftimie|first3=Ion A.|date=2020|title=Nuclear Fusion Diffusion: Theory, Policy, Practice, and Politics Perspectives |url=https://ieeexplore.ieee.org/document/9078039|journal=IEEE Transactions on Engineering Management|volume=69 |issue=4 |pages=1237–1251|doi=10.1109/TEM.2020.2982101|s2cid=219001461|issn=1558-0040}}</ref> the neutron flux turns the structural materials radioactive. The amount of radioactive material at shut-down may be comparable to that of a fission reactor, with important differences. The half-lives of fusion and neutron activation [[radioisotopes]] tend to be less than those from fission, so that the hazard decreases more rapidly. Whereas fission reactors produce waste that remains radioactive for thousands of years, the radioactive material in a fusion reactor (other than tritium) would be the reactor core itself and most of this would be radioactive for about 50 years, with other low-level waste being radioactive for another 100 years or so thereafter.<ref>{{cite journal |first1=Anil |last1=Markandya |first2=Paul |last2=Wilkinson |s2cid=25504602 |url=http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(07)61253-7/fulltext |journal=The Lancet |volume=370 |issue=9591 |year=2007 |title=Electricity generation and health |pages=979–990 |doi=10.1016/S0140-6736(07)61253-7 |pmid=17876910 |access-date=February 21, 2018}}</ref> The fusion waste's short half-life eliminates the challenge of long-term storage. By 500 years, the material would have the same [[radiotoxicity]] as [[coal ash]].<ref name="WorldEnergyCouncil">{{cite web |last1=Hamacher |first1=T. |last2=Bradshaw |first2=A. M. |date=October 2001 |title=Fusion as a Future Power Source: Recent Achievements and Prospects |url=http://www.worldenergy.org/wec-geis/publications/default/tech_papers/18th_Congress/downloads/ds/ds6/ds6_5.pdf |archive-url=https://web.archive.org/web/20040506065141/http://www.worldenergy.org/wec-geis/publications/default/tech_papers/18th_Congress/downloads/ds/ds6/ds6_5.pdf |archive-date=May 6, 2004 |publisher=World Energy Council}}</ref>
Nonetheless, classification as intermediate level waste rather than low-level waste may complicate safety discussions.<ref>{{Cite journal|last1=Nicholas|first1=T. E. G.|last2=Davis|first2=T. P.|last3=Federici|first3=F.|last4=Leland|first4=J.|last5=Patel|first5=B. S.|last6=Vincent|first6=C.|last7=Ward|first7=S. H.|date=February 1, 2021|title=Re-examining the role of nuclear fusion in a renewables-based energy mix|url=https://www.sciencedirect.com/science/article/pii/S0301421520307540|journal=Energy Policy|language=en|volume=149|pages=112043|doi=10.1016/j.enpol.2020.112043|issn=0301-4215|arxiv=2101.05727|bibcode=2021EnPol.14912043N |s2cid=230570595}}</ref><ref name="demonstration" />

The choice of materials is less constrained than in conventional fission, where many materials are required for their specific [[neutron cross-section]]s. Fusion reactors can be designed using "low activation", materials that do not easily become radioactive. [[Vanadium]], for example, becomes much less radioactive than [[stainless steel]].<ref>{{Cite journal |last1=Cheng |first1=E. T. |last2=Muroga |first2=Takeo |date=2001 |title=Reuse of Vanadium Alloys in Power Reactors |url=http://dx.doi.org/10.13182/fst01-a11963369 |journal=Fusion Technology |volume=39 |issue=2P2 |pages=981–985 |bibcode=2001FuTec..39..981C |doi=10.13182/fst01-a11963369 |issn=0748-1896 |s2cid=124455585}}</ref> [[Carbon fiber]] materials are also low-activation, are strong and light, and are promising for laser-inertial reactors where a magnetic field is not required.<ref>{{Cite journal|last1=Streckert|first1=H. H.|last2=Schultz|first2=K. R.|last3=Sager|first3=G. T.|last4=Kantncr|first4=R. D.|date=December 1, 1996|title=Conceptual Design of Low Activation Target Chamber and Components for the National Ignition Facility|url=https://doi.org/10.13182/FST96-A11962981|journal=Fusion Technology|volume=30|issue=3P2A|pages=448–451|doi=10.13182/FST96-A11962981|bibcode=1996FuTec..30..448S |issn=0748-1896|citeseerx=10.1.1.582.8236}}</ref>