Editing Integral fast reactor (section)

===Nuclear waste===
The waste products of IFR reactors either have a short half-life, which means that they decay quickly and become relatively safe, or a long half-life, which means that they are only slightly radioactive. Neither of the two forms of IFR waste produced contain plutonium or other [[actinides]]. Due to pyroprocessing, the total volume of true waste/[[fission products]] is 1/20th the volume of spent fuel produced by a light-water plant of the same power output, and is often considered to be all unusable waste. 70% of fission products are either stable or have half-lives under one year. [[Technetium-99]] and [[iodine-129]], which constitute 6% of fission products, have very long half-lives but can be [[Nuclear transmutation|transmuted]] to isotopes with very short half-lives (15.46 seconds and 12.36 hours) by neutron absorption within a reactor, effectively destroying them (see more: [[long-lived fission product]]s). [[Isotopes of zirconium|Zirconium-93]], another 5% of fission products, could in principle be recycled into fuel-pin cladding, where it does not matter that it is radioactive. Excluding the contribution from [[transuranic waste]] (TRU) – which are isotopes produced when [[uranium-238]] captures a slow [[thermal neutron]] in an LWR but does not fission – all [[high level waste]]/fission products remaining after reprocessing the TRU fuel is less radiotoxic (in [[sievert]]s) than [[natural uranium]] (in a gram-to-gram comparison) within 200–400 years, and continues to decline afterward.<ref>{{cite web |url=https://www.youtube.com/watch?v=UA5sxV5b5b4 |archive-url=https://ghostarchive.org/varchive/youtube/20211212/UA5sxV5b5b4| archive-date=2021-12-12 |url-status=live|title=Dealing with the Used Fuel (Reprocessing)|author=Professor David Ruzic|website=[[YouTube]] |date=14 May 2019 }}{{cbignore}}</ref><ref name="pg 15 see SV/g chart">{{cite journal|url=http://www.stralsakerhetsmyndigheten.se/Global/Publikationer/Tidskrift/Nucleus/2007/Nucleus-4-2007.pdf |title=Återanvändning av lång sluten bränslecykel möj |journal=Nucleus |author=Janne Wallenius |date=2007-04-01 |page=15 |url-status=dead |archive-url=https://web.archive.org/web/20140519002715/http://www.stralsakerhetsmyndigheten.se/Global/Publikationer/Tidskrift/Nucleus/2007/Nucleus-4-2007.pdf |archive-date=2014-05-19 }}</ref><ref name="berkeley" />{{Unreliable source?|date=July 2012}}<ref name="https"/>{{better source|date=July 2014}}
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Edwin Sayre has estimated that a ton of fission products (which includes the very weakly radioactive [[palladium-107]]), when reduced to metal, has a market value of $16 million.<ref>[http://brc.gov/e-mails/August10/Commercial Value of 1 Metric ton of used fuel.pdf]{{Dead link|date=July 2012}}</ref>--><!--This source pdf has been lost. No backup on Wayback Machine. Internet search yields some identical references, but no source. Cannot verify.-->

The on-site reprocessing of fuel means that the volume of high-level nuclear waste leaving the plant is tiny compared to LWR spent fuel.{{NoteTag|Estimates from Argonne National Laboratory place the output of waste of a 1,000&nbsp;[[MWe]] plant operating at 70% capacity at 1,700&nbsp;pounds/year.<ref name="berkeley" />}} In fact, in the U.S. most spent LWR fuel has remained in storage at the reactor site instead of being transported for reprocessing or placement in a [[geological repository]]. The smaller volumes of [[high level waste]] from reprocessing could stay at reactor sites for some time, but are intensely radioactive from [[medium-lived fission products]] (MLFPs) and need to be stored securely, like in [[dry cask storage]] vessels. In its first few decades of use, before the MLFPs decay to lower levels of heat production, geological repository capacity is constrained not by volume but by heat generation. This limits early repository emplacement. [[Decay heat]] generation of MLFPs from IFRs is about the same per unit power as from any kind of fission reactor.

The potential complete removal of plutonium from the waste stream of the reactor reduces the concern that now exists with spent nuclear fuel from most other reactors, namely that a spent fuel repository could be used as a [[Radioactive waste#Proliferation concerns|plutonium mine]] at some future date.{{sfnp|U.S. Congress|1994|p=30}} Also, despite the million-fold reduction in radiotoxicity offered by this scheme,{{NoteTag|Radioactivity and its associated dangers are roughly divided by an isotope's half-life. For example, given the 213,000-year half-life of technetium-99, combined with the IFR's 1/20 volume reduction, produces about 1/4,000,000 of the radiotoxicity of light-water reactor waste. The small size (about 1.5 tonnes per gigawatt-year) permits expensive disposal methods such as insoluble synthetic rock. The hazards are far less than those from fossil fuel wastes or dam failures.}} there remain concerns about radioactive longevity:<blockquote>[Some believe] that actinide removal would offer few if any significant advantages for disposal in a [[geologic repository]] because some of the ''fission product'' [sic] [[nuclide]]s of greatest concern in scenarios such as [[Leaching (chemical science)|leaching]] into [[groundwater]] actually have longer half-lives than the radioactive actinides. The concern about a waste cannot end after hundreds of years even if all the actinides are removed when the remaining waste contains radioactive fission products such as technetium-99, iodine-129, and cesium-135 with the half-lives between 213,000 and 15.7 million years.{{sfnp|U.S. Congress|1994|p=30}}</blockquote>However, these concerns do not consider the plan to store such materials in insoluble [[Synroc]], and do not measure hazards in proportion to those from natural sources such as medical [[x-ray]]s, [[cosmic ray]]s, or naturally radioactive rocks (such as [[granite]]).{{Citation needed|date=July 2024}} Furthermore, some of the radioactive fission products are being targeted for [[Nuclear transmutation|transmutation]], belaying even these comparatively low concerns. For example, the IFR's positive [[void coefficient]] could be reduced to an acceptable level by adding technetium to the core, helping destroy the long-lived fission product [[technetium-99]] by [[nuclear transmutation]] in the process.<ref name="osti.gov">[http://www.osti.gov/bridge/servlets/purl/10171782-o1Ys0R/10171782.pdf Reduction of the Sodium-Void Coefficient of Reactivity by Using a Technetium Layer] page 2</ref>