Development of an Innovative Electrorefiner for High Uranium Recovery Rate from Metal Fast Reactor Fuels

Abstract

To increase the uranium recovery rate of molten salt electrorefining step in pyrometallurgical reprocessing of metallic fast reactor fuels, tests were carried out using electrorefiners equipped with mechanisms for scraping cathode deposits. After the modifications in the design of the anode basket and scraper mechanism, no stalling of the anode and scraper rotation due to interference by cathode deposits occurred. Under the condition that codissolution of zirconium and uranium was allowed in order to obtain maximum throughput, a current of 400-450 A was maintained until 82% of the initially loaded uranium was recovered. The uranium recovery rate for the same duration reached 789 g U/h (32.9 g U/hÁL per electrode volume). On the assumption that an electrorefiner operates for 20 h/d and 200 d/y in an actual pyrometallugical reprocessing facility, this result corresponds to a uranium recovery rate of 3.16 t U/y using only one electrode assembly of about 30 cm diameter, which should be a sufficiently high performance for practical use. From these results, the engineering feasibility of uranium recovery using an electrorefiner with cathode deposit scraper mechanism has been demonstrated.

Behavior of U-Zr Alloy Containing Simulated Fission Products during Anodic Dissolution in Molten Chloride Electrolyte

“…The detailed description, operating method, and evaluated performance characteristics, such as processing rate and operation stability, were already given in the previous report. 7) Both apparatuses were installed in glove boxes with a highly purified argon atmosphere. The oxygen and moisture levels in the atmosphere were kept at less than 10 ppm during the tests.…”

“…The volume and weight of the alloy held in the tubes were then estimated from the diameter and density of the alloy. 7) The amount of each element in the analyzed pieces was calculated using the alloy composition (Table 1), and the remaining ratios were finally evaluated, as shown in Table 4. In some samples, the calculated remaining ratios were largely scattered due to the inhomogeneity of the samples and analytical error, particularly for NMs.…”

“…Thus, the authors have carried out electrorefining tests using an electrorefining apparatus equipped with mechanisms for scraping cathode deposits in order to increase the uranium recovery rate. 7) Figure 2 shows the schematic view of the electrorefining apparatus developed in the above-mentioned study. The electrode assembly consists of a cylindrical cathode and anode baskets rotating inside the cathode.…”

Recovery of uranium using electrorefining with an anode-liquid cathode module (ALCM) in molten LiCl–KCl–UCl3–NdCl3 and cadmium distillation

“…The Argonne National Laboratory (ANL, US) has developed an electrorefiner in which anode baskets are rotated inside multiple cathodes [5]. The Central Research Institute of Electric Power Industry (CRIEPI, Japan) developed an electrorefiner equipped with a scraper system [7]. We have reported an anode-liquid cathode module (ALCM) with a compact structure to enhance the metal recovery rate of the LCC electrorefiner [8].…”

Use of a single fuel containment material during pyroprocessing tests

“…In the electrorefining process, which is conducted at 500°C, the actinide metals are electrochemically dissolved and transported to the bulk LiCl-KCl-UCl 3 molten salt via a permeable anode basket and simultaneously, high purity U metal is deposited on a solid stainless steel or graphite cathode ( (Iizuka et al, 2009(Iizuka et al, , 2010Kato et al, 2006;Li et al, 2005;Vaven et al, 2008).…”