Certification of 244Pu spike reference material: IRMM-042a : Certified reference material for the amount content of 244Pu and Pu isotope amount ratios

Autor: BUJAK RENATA, JAKOPIC ROZLE, EYKENS ROGER, KEHOE FRANCES, KÜHN H., RICHTER STEPHAN, AREGBE YETUNDE
Jazyk: angličtina
Rok vydání: 2017
Popis: IRMM-042a is an existing spike Certified Reference Material (CRM) of highly enriched 244Pu that has been re-certified for the amount content of 244Pu and for the plutonium isotope amount ratios. Since the reference material was produced 30 years ago, there have been significant improvements in analytical instruments and methods. Accordingly, the uncertainty of the 244Pu amount content of the original material certificate was considered to be too large. Furthermore, recent measurements of a plutonium external quality control certified test sample (EQRAIN Plutonium Program No 11) by Isotope Dilution Thermal Ionization Mass Spectrometry (ID-TIMS) using the IRMM-042a indicated a slight deviation from the previous value for the amount content of 244Pu as certified in 1987. Therefore, it was decided to perform a new series of certification measurements in compliance with ISO 17034:2016 [ ] and to issue a new certificate. Between-unit homogeneity was quantified in accordance with ISO Guide 35:2006 [ ]. No dedicated stability studies were carried out for this material since the general behaviour of this material is well known from past experience. However, a post-certification stability monitoring will be carried out to evaluate its stability after issuance of the certificate. The certified value for the amount content of 244Pu was obtained from the characterisation measurements on randomly selected units by ID-TIMS using the IRMM-049d 242Pu CRM as the spike. The plutonium isotope amount ratios were measured by Triton TIMS. Uncertainties of the certified values were estimated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) [ ] and include uncertainties related to possible inhomogeneity and to characterisation. The main purpose of this material is for use as a spike isotopic reference material to measure the amount content of plutonium in nuclear and environmental samples by isotope dilution mass spectrometry (IDMS). The IRMM-042a CRM is supplied in flame sealed glass ampoules containing about 10 mL of nitric acid solution (c = 5 mol/L) with a mass fraction of plutonium of about 1 μg/g solution. The material is a true solution; therefore there is no recommended minimum sample intake to be taken into account.
JRC.G.2-Standards for Nuclear Safety, Security and Safeguards
Databáze: OpenAIRE