only slightly radioactive. 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 all considered to be 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 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 products). 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 U-238 captures a slow thermal neutron in a LWR but does not fission, all the remaining high level waste/fission products("FP") left over from reprocessing out the TRU fuel, is less radiotoxic(in Sieverts) than natural uranium(in a gram to gram comparison) within 400 years, and it continues its decline following this. Edwin Sayre has estimated that a ton of fission products(which also include the very weakly radioactive Palladium-107 etc.) reduced to metal, has a market value of $16 million. The two forms of IFR waste produced, contain no plutonium or other actinides. The radioactivity of the waste decays to levels similar to the original ore in about 300–400 years. 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. 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 the present Dry cask storage vessels. In its first few decades of use, before the MLFP's decay to lower heat producing levels, geological repository capacity is constrained not by volume but by heat generation, and decay heat generation from medium-lived fission products is about the same per unit power from any kind of fission reactor, limiting early repository emplacement. The potential complete removal of plutonium from the waste stream of the reactor reduces the