Ben Russell

Development of an optimised method for analysis of 90Sr in decommissioning wastes by triple quadrupole inductively coupled plasma mass spectrometry

The ongoing development of an optimised procedure for the measurement of 90Sr in decommissioning samples using the latest generation triple quadrupole inductively coupled plasma mass spectrometry (ICP-QQQ-MS) is presented. The procedure incorporates digestion, and separation from interferences using a combination of wet chemical and instrument-based separation using the ICP-QQQ-MS reaction cell. The key factors under study are the procedural time and limits of detection achievable compared to existing radiometric techniques.

Development of a method for rapid analysis of Ra-226 in groundwater and discharge water samples by ICP-QQQ-MS

A novel and rapid method has been developed for pre-concentration and measurement of 226Ra in groundwater and discharge water samples using the latest generation triple quadrupole inductively coupled plasma mass spectrometry (ICP-QQQ-MS). Cation exchange and extraction chromatography are capable of pre-concentration factors of ~200 based on 1L samples. The sensitivity and interference removal capability of ICP-QQQ-MS was assessed from spiked groundwaters, with the introduction of He collision gas required to minimise instrument background in high-matrix samples. The technique developed is potentially capable of detecting 226Ra activities as low as 5mBqL-1 when combined with pre-concentration prior to measurement.

The behaviour of 226Ra in high-volume environmental water samples on TK100 resin

Accurate, low-level measurement of 226Ra in high volume water samples requires rapid pre-concentration and robust separation techniques prior to measurement in order to comply with discharge limits and drinking water regulations. This study characterises the behaviour of 226Ra and interfering elements on recently developed TK100 (Triskem International) extraction chromatography resin. Distribution coefficients over a range of acid concentrations are given, along with an optimised procedure that shows rapid pre-concentration and separation of 226Ra on TK100 resin is achievable for high volume (1 L) water samples without the need for sample pre-treatment.

Isolation and purification of protactinium-231

Protactinium-231 is one of the lesser known actinides, yet the measurement of this radionuclide is central to dating studies in both paleoclimate and nuclear forensics measurements; furthermore, it is important as the immediate parent nuclide of the 227Ac decay chain. In this paper, we present the preparatory work for an upcoming CCRI(II) supplementary comparison of this radionuclide. The material used in this work was of poorly known provenance, and it was necessary to carry out a chemical purification of this material prior to use. A new extraction chromatography resin, TK 400, which has been developed for the separation of 231Pa, was tested at NPL. The aims of the work were achieved; the recovery of 231Pa was ~85%, the decay products were recovered in good yield (~95%) and stable element impurities were removed.

Metrology for decommissioning nuclear facilities: partial outcomes of joint research project within the European Metrology Research Program

Decommissioning of nuclear facilities incurs high costs regarding the accurate characterisation and correct disposal of the decommissioned materials. Therefore, there is a need for the implementation of new and traceable measurement technologies to select the appropriate release or disposal route of radioactive wastes. This paper addresses some of the innovative outcomes of the project Metrology for Decommissioning Nuclear Facilities related to mapping of contamination inside nuclear facilities, waste clearance measurement, Raman distributed temperature sensing for long term repository integrity monitoring and validation of radiochemical procedures.

Measurement of 151 Sm in nuclear decommissioning samples by ICP-MS/MS

Abstract151Sm [half-life 94.7 (6) years] is a fission and activation product that requires accurate measurement as part of nuclear decommissioning. A procedure is outlined for the measurement of 151Sm in spiked graphite samples. Digestion is performed by automated lithium borate fusion, followed by extraction chromatography separation of 151Sm from interfering lanthanide isotopes, primarily europium. Measurement is carried out using tandem inductively coupled plasma mass spectrometryxa0(ICP-MS/MS), using the integrated collision/reaction cell as a rapid support to radiochemical separation of 151Sm from isobaric 151Eu using oxygen as a reactive gas, achieving detection limits below the out-of-scope limit for 151Sm.

Selective sorption of uranium from aqueous solution by graphene oxide-modified materials

The effect of competing ions on the sorption behaviour of uranium onto carboxyl-functionalised graphene oxide (COOH-GO) were studied in batch experiments in comparison to graphene oxide (GO) and graphite. The effect of increasing the abundance of select chemical functional groups, such as carboxyl groups, on the selectivity of U sorption was investigated. In the course of the study, COOH-GO demonstrated superior performance as a sorbent material for the selective removal of uranyl ions from aqueous solution with axa0distribution coefficient of 3.72xa0±xa00.19xa0×xa0103xa0mLxa0g−1 in comparison to 3.97xa0±xa00.5xa0×xa0102 and 2.68xa0±xa00.2xa0×xa0102xa0mLxa0g−1 for GO and graphite, respectively.

Rare earth elements and 143Nd/144Nd isotope ratio measurements using tandem ICP-CRC-MS/MS: characterization of date palm (Phoenix dactylifera L.)

Herein, tandem inductively coupled plasma mass spectrometry with a collision/reaction cell (ICP-CRC-MS/MS) was used to accurately characterize the rare earth element (REE) pattern and the radiogenic isotope ratios of 143Nd/144Nd. Plant and soil samples were digested with concentrated acids, and the sample solutions were diluted and directly measured using ICP-CRC-MS/MS. Oxygen (O2) was used to exclude polyatomic interferences with the concerned masses of the REEs. Carbon dioxide (CO2) was introduced into the reaction cell to eliminate the 144Sm isobar via the indirect mass shift mode from Nd+ to NdO+. The methods were validated by measuring standard reference materials. For quality assurance, the REEs and Nd were chemically separated and then measured using ICP-CRC-MS/MS in a single quad mode, in which the first quadrupole served as only an ion guide. The REE pattern and radiogenic isotope ratios of 143Nd/144Nd were identified in date palm (Phoenix dactylifera L.) obtained from three countries in the Arabian Peninsula: Qatar, Kuwait, and Saudi Arabia.

Evaluation of the separation and purification of 227Th from its decay progeny by anion exchange and extraction chromatography

Thorium-227 is currently undergoing evaluation as a potential radionuclide for targeted cancer therapy, and as such a high chemical purity of the material is required. To establish a reliable procedure for radiochemical isolation of 227Th from the parent 227Ac and decay progeny, which includes the radiotherapeutic 223Ra, the performance of three different separation schemes based on ion-exchange and extraction chromatography have been evaluated. The results suggest that both ion exchange and extraction chromatographic techniques can be successfully used for the separation of 227Th from its decay progeny, however extraction chromatographic resins demonstrate favourable performance in terms of Th recovery and purification from radionuclide impurities.