Palladium in Irradiated Fuel. Are There Any Prospects for Recovery and Application?

Abstract

Published data on the speciation and behavior of Pd in different stages of reprocessing of irradiated fuel from NPPs were analyzed. Various methods for recovering Pd from solutions and solids of different compositions, arising in reprocessing, were described. The Pd sales volumes in the recent decades were reported, and possible industrial and technical applications of Pd were discussed. An opinion is expressed that it is of interest to recover [reactor-grade] Pd to be used in reprocessing of the waste from radiochemical enterprises (e.g., immobilization of 129 I and/or TPEs), i.e., in processes where the presence of radioactive nuclide 107 Pd does not matter and exhaustive removal of other fission products is not required.The history of science and technology abounds in cases where ideas, set aside many years ago, are revived. This is true of the attempted recovery of platinum group metals (PGMs) from irradiated fuel of NPPs. The first relevant publications [133] appeared about 50 years ago, and their authors considered it very attractive to find the possibilities of recovering Pd and Rh whose yield in uranium fission products is fairly high, namely, kilograms per ton of fuel. But as yet, no country has succeeded in developing an acceptable method for commercial recovery of platinum metals from real radioactive solutions. This is due to a number of reasons.The main purpose of irradiated nuclear fuel reprocessing is to recover U and Pu and to localize fission products, rather than to recover individual radionuclides intended for commercial purposes. On the other hand, the use of any radionuclides, even minimally active, is extremely negatively received by the public. Probably, this is the most significant negative factor that questions the appearance of a demand for [reactor-grade] Pd or Rh in their traditional application spheres, even if they will be cheaper than Pd and Rh extracted from ores.At the same time, depletion of mineral resources of platinum metals will sooner or later cause their prices to rise to the level when irradiated fuel could become a real substitute to their commercial production sources. Since recently, technologies for high-level waste (HLW) partitioning have been developed, which would yield solutions that are less active and simpler in composition than the first extraction cycle raffinates containing all the fission products and, thus, will be suitable for recovery of Pd and Rh.In this work, we analyzed publications on recovery of Pd from irradiated fuel. Since the prospects for commercial recovery of Pd are directly related to technical demands and natural reserves, we considered it necessary to supplement this review with a section devoted to possible applications of Pd and its compounds.

Direct Selective Extraction of Actinides (III) from PUREX Raffinate using a Mixture of CyMe4BTBP and TODGA as 1-cycle SANEX Solvent

“…[33][34][35] In particular, the use of these valuable elements in nuclear applications is of greater interest because the presence of minor amounts of radioactive nuclides does not matter and a complete removal of other fission products may not be required. [36] The use of Platinum Group Metals (PGM) in automotive catalytic converters to treat automobile exhaust emissions and the application of PGM as catalysts in large-scale industrial processes has expanded the need for these metals. Although automotive catalytic converters are recycled and PGM are currently extracted and separated, the recycling process is unable to fulfill the demands of industry.…”

Palladium electrodeposition in 1-butyl-1-methylpyrrolidinium dicyanamide ionic liquid

“…Pd electrodeposition has major applications in electronics industry (interconnects, circuits), auto industry (interconnects, catalysts), decorative industry (jewelry, ornaments) and its recovery from spent nuclear fuel [1,2]. Hydrogen embrittlement is a major issue when electroplating Pd films [1].…”

Studies on the feasibility of electrochemical recovery of palladium from high-level liquid waste

“…have been reported for the recovery of palladium. Excellent reviews in this regard by Kolarik and Renard [3,7,8], and Pokhitonov and Romanovskii [9], detail the methods reported to date for the separation of fission platinoids. The electrochemical method for the separation and recovery of palladium is one of the easy and promising techniques due to its simplicity, accessibility of reduction potential of palladium in nitric acid medium.…”