Certification of the uranium hexafluoride (UF6) isotopic composition: The IRMM-019 to IRMM-029 series

This report describes the re-determination and certification of the IRMM-019 to IRMM-029 series of uranium hexafluoride (UF6) reference materials certified for the uranium isotopic composition. The values were assigned following ISO Guide 34:2009. The IRMM-019 to IRMM-029 series was originally produced and certified in the 1980's-1990's. Since, the materials are stored in monel ampoules. Upon customer request, UF6 gas is distilled from a mother ampoule into a daughter ampoule, the isotopic composition is verified by Gas Source Mass Spectrometry (GSMS) and the daughter ampoule is sent to the customer. For the purpose of this project, the UF6 materials were converted into uranium nitrate solutions to perform the homogeneity and characterisation studies. Between-unit homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The materials were characterised by Thermal Ionisation Mass Spectrometry (TIMS) using newly established measurement procedures such as the Modified Total Evaporation (MTE) and Double Spike (DS) methods, and with a new set of certified uranium isotope reference materials, which were prepared by gravimetrical mixing of highly enriched 233U, 235U, 236U and 238U oxides or solutions. The results of the characterisation measurements were also confirmed by GSMS measurements using the original UF6 gases. 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 the characterisation measurements and the homogeneity study. The materials are intended for the calibration of methods, quality control purposes, and the assessment of method performance for isotope mass spectrometry. As with any certified reference material, they can also be used for validation studies. The CRMs are available in monel ampoules. Based on physical reasons, there is no minimum sample intake to be taken into account.JRC.D.2-Standards for Innovation and sustainable Developmen

CERTIFICATION REPORT: Preparation and Certification of Large-Sized Dried (LSD) Spike - IRMM-1027q

IRMM Large-Sized Dried (LSD) Spikes are widely used as a fundamental part of the fissile material control of irradiated nuclear fuel and have been provided on a regular basis to safeguards authorities and industry for more than 10 years. This report describes the preparation and certification of a new batch of LSD Spikes. IRMM-1027q is a dried nitrate material in cellulose acetate butyrate (CAB), certified for the mass of uranium and plutonium and isotope amount ratios per unit. The material was produced following ISO Guide 34:2009. The certified reference materials uranium metal EC NRM 101, enriched uranium metal NBL CRM 116-A and plutonium metal CETAMA MP2 were used as starting materials to prepare the mother solution. This solution was dispensed by means of an automated robot system into individual units and dried down. A solution of an organic substance, cellulose acetate butyrate (CAB), was dried on the spike material as a stabiliser to retain the dried material at the bottom of the vial. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The certified values for the uranium and plutonium isotope amount ratios and for the mass of uranium per unit were obtained from the gravimetric preparation of the mother solution, taking into account the mass, purity and isotopic abundances of the starting materials, the mass of the mother solution, and the mass of an aliquot in each individual unit. The certified values for the mass of plutonium per unit were established by isotope dilution thermal ionisation mass spectrometry (ID-TIMS). Confirmatory measurements were performed by isotope dilution thermal ionisation mass spectrometry (ID-TIMS) and thermal ionisation mass spectrometry (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. This spike CRM is applied as a calibrant to measure the uranium and plutonium amount content of dissolved spent nuclear fuel solutions using isotope dilution mass spectrometry (IDMS). Each unit contains about 55 mg of uranium with a relative mass fraction m(235U)/m(U) of 17.7 % and 1.9 mg of plutonium with a relative mass fraction m(239Pu)/m(Pu) of 97.8 % as dried nitrates in CAB. The whole amount of sample per unit has to be used for analysis.JRC.D.2-Standards for Innovation and sustainable Developmen

Preparation and Certification of Large-Sized Dried (LSD) Spike – IRMM-1027s

Large-Sized Dried (LSD) spikes are used as a fundamental part of the fissile material control of irradiated nuclear fuel and have been provided on a regular basis to safeguards authorities and industry for more than 10 years. This report describes the preparation and certification of a new batch of LSD spikes. IRMM-1027s is a dried nitrate material in cellulose acetate butyrate (CAB), certified for the mass of uranium and plutonium and the uranium and plutonium isotope amount ratios per unit. The material was produced in compliance with ISO/IEC 17034:2016 and certified in accordance with ISO Guide 35:2006. The certified reference materials uranium metal EC NRM 101, enriched uranium metal NBL CRM 116-A and plutonium metal CETAMA MP2 were used as starting materials to prepare the mother solution. This solution was dispensed into individual units by means of an automated robot system and dried down. A solution of an organic substance, cellulose acetate butyrate (CAB) was dried on the spike material as a stabiliser to retain the dried material at the bottom of the vial. In total 950 units were produced. Between-unit homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The certified values for the uranium and plutonium isotope amount ratios were obtained from the gravimetric preparation of the mother solution, taking into account the mass, purity and isotopic composition of the starting materials. The certified values for the mass of plutonium and uranium per unit were established by isotope dilution thermal ionisation mass spectrometry (ID-TIMS) on randomly selected units. External verification measurements were performed by isotope dilution mass spectrometry (IDMS) and thermal ionisation mass spectrometry (TIMS) on randomly selected units of IRMM-1027s. 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 plutonium and uranium amount content of spent nuclear fuel solutions using IDMS. Each unit contains about 55 mg of uranium with a relative mass fraction m(235U)/m(U) of 19.0 % and 1.7 mg of plutonium with a relative mass fraction m(239Pu)/m(Pu) of 97.8 % as dried nitrates in CAB. The whole amount of sample per unit has to be used for analysis.JRC.G.2-Standards for Nuclear Safety, Security and Safeguard

Source Apportionment of Nitrate Pollution in Surface Water Using Stable Isotopes of N and O in Nitrate and B: A Case Study in Flanders (Belgium)

Excess application to fields of animal manure or mineral fertilizers is generally assumed to be the major source of nitrate pollution in surface and groundwater in agricultural areas in Flanders (Belgium). The Flemish Environment Agency (VMM) suspects, but could not prove, that discharges of untreated domestic sewage or discharges containing mineral fertilizers from hydroculture in greenhouses are also contributing to the nitrate pollution observed in some of the agricultural areas. The objective of this study was to investigate, using stable isotope data of dissolved nitrate and boron, if these suspected sources significantly contribute to the nitrate pollution observed in selected surface water monitoring points in Flanders.JRC.D.4-Isotope measurement

CERTIFICATION REPORT: Preparation and certification of a new batch of 242Pu spike: IRMM-049e

This report describes the preparation and certification of the 242Pu spike reference material IRMM-049e, applied for determination of plutonium content in nuclear materials by isotope dilution mass spectrometry (IDMS) in nuclear safeguards, nuclear security and in the industry. As the stock of IRMM-049d is close to exhaustion, it was decided to produce about 90 ampoules of a new spike certified reference material (CRM) IRMM-049e and, therefore to maintain the provision of the IRMM-049 series of spike CRMs. IRMM-049e is the first of the IRMM-049 series produced in compliance with ISO 17034:2016. The amount content of 242Pu in IRMM-049e was characterised on 10 randomly stratified selected units by Isotope Dilution – Thermal Ionisation Mass Spectrometry (ID-TIMS) using the IRMM-1027o CRM as a spike. The plutonium isotope amount ratios were measured using the same 10 selected units by TIMS. The material was finally certified for the amount content of 242Pu and the total Pu, the mass fractions of 242Pu and total Pu, the Pu isotope amount ratios as well as the plutonium isotope abundances as amount and mass fractions, and for the molar mass of Pu in IRMM-049e. The certified values were confirmed by ID-TIMS using the IRMM-086 (239Pu spike) and verified against the reference value of the external certified test sample Pu EQRAIN-13 provided by CEA/CETAMA. These verification studies were carried out in the frame of the on-going inter-calibration campaign using state-of-the art measurement procedures linking together different JRC plutonium spike reference materials and also external reference materials to underpin the confidence in the use of JRC isotopic plutonium reference materials for safeguards verification. Between unit-homogeneity was quantified in accordance with ISO Guide 35:2006. No stability study was performed for this reference material since the general behaviour of this material is well known from past experience. However, a post-certification stability monitoring will be done every two years to control its stability after issuance of the certificate. The 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 characterisation and possible inhomogeneity. The main purpose of this material is for use as a spike isotopic reference material for quantification of plutonium in an unknown nuclear sample. IRMM-049e is supplied in a screw-cap glass ampoule containing 10 mL nitric acid solution (c = 5 mol/L) with a certified plutonium (total Pu) mass fraction of (91.52 ± 0.12) µg/g and a certified 242Pu amount content of (0.35828 ± 0.00045) µmol/g. Because the IRMM-049e material is a true solution and as such, can be regarded as completely homogeneous, there is no minimum sample intake to be taken into account for the analysis.JRC.G.2-Standards for Nuclear Safety, Security and Safeguard

Preparation and certification of Large-Sized Dried (LSD) Spike - IRMM-1027p

IRMM Large-Sized Dried (LSD) Spikes are widely used as a fundamental part of the fissile material control of irradiated nuclear fuel and have been provided on a regular basis to safeguards authorities and industry for more than 10 years. This report describes the preparation and certification of a new batch of LSD Spikes. IRMM-1027p is a dried nitrate material in cellulose acetate butyrate (CAB), certified for the mass of uranium and plutonium and isotope amount ratios per unit. The material was produced following ISO Guide 34:2009. The certified reference materials uranium metal EC NRM 101, enriched uranium metal NBL CRM-116 and plutonium metal CETAMA MP2 were used as starting materials to prepare the mother solution. This solution was dispensed by means of an automated robot system into individual units and dried down. A solution of an organic substance, cellulose acetate butyrate (CAB), was dried on the spike material as a stabiliser to retain the dried material at the bottom of the vial. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The certified values were obtained from the gravimetric preparation of the mother solution, taking into account the mass, purity and isotopic abundances of the starting materials, the mass of the mother solution, and the mass of an aliquot in each individual unit. The certified values were confirmed by isotope dilution thermal ionisation mass spectrometry (ID-TIMS) and thermal ionisation mass spectrometry (TIMS) as independent confirmation methods. 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. This spike CRM is applied as a calibrant to measure the uranium and plutonium amount content of dissolved spent nuclear fuel solutions using isotope dilution mass spectrometry (IDMS). Each unit contains about 50 mg of uranium with a relative mass fraction m(235U)/m(U) of 17.4 % and 1.8 mg of plutonium with a relative mass fraction m(239Pu)/m(Pu) of 97.8 % as dried nitrates in CAB. The whole amount of sample per unit has to be used for analysis.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Reading other worlds, reading my world

In this article, Carmel Hinchion and Jennifer Hennessy reflect on a project undertaken by the Ubuntu Network in partnership with pre-service English teachers and their lecturers at the University of Limerick. The project was set in the context of an English pedagogy course as part of the undergraduate initial teacher education (ITE) programme where student English teachers prepare for teaching in post-primary classrooms. Their article focuses on a literature unit where ‘culturally salient’ texts were chosen to promote, not only a reading of the word but of the world (Freire, 1970). A culturally salient text, as understood by Kress (1995), is one that allows us to ask questions about its significance in its own cultural domain and for other cultures. Drawing on the metaphor of a ‘reconstitutive mirroring experience’ (O’Loughlin, 2009), literature acts as a reflexive and reflective medium in shaping a world view

Poetry and pedagogy: Exploring the opportunity for epistemological and affective development within the classroom

Abstract This paper provides a review of the priority afforded to the development of pupils &apos

“The points, the points, the points”: exploring the impact of performance oriented education on the espoused values of senior cycle poetry teachers in Ireland

Teachers of English experience significant pressure in attempting to meet the requirements of the national examination system, while also seeking to uphold their own ideological and philosophical perspectives on the value of poetry. Drawing on a mixed method study into the teaching of poetry at post-primary level in Ireland conducted between 2007 and 2010, this paper examines current methodological trends in poetry pedagogy. The research identifies a marked imbalance in the prioritisation of pupil development, with many teachers privileging the cognitive development of pupils’ poetic understanding over the affective. The paper also suggests limited attention to the interwoven dimensions of the affective and cognitive domains in the teaching of poetry at senior cycle level in Irish schools. This paper advocates the need to support teachers to develop an integrated pedagogy for teaching poetry in second-level schools, which engages both the critical and the creative in a meaningful manner

An inter-calibration campaign using selected uranium isotopic reference materials

Isotope dilution mass spectrometry (IDMS) is one of the most widely applied techniques for the measurement of uranium and plutonium amount content in nuclear safeguards, especially when accurate results with small uncertainties are required. Intrinsic to IDMS is the use of certified isotopic reference materials; so-called spike CRMs. Reference materials with certified amount content and isotope ratios are indispensable for instrument calibration and method validation. Their fundamental role is to establish traceability of the measured value to a unit of measurement as defined in the International System of Units (SI), and further to estimate properly the measurement uncertainty. At the Institute for Reference Materials and Measurements of the Joint Research Centre of the European Commission (EC-JRC-IRMM) various plutonium and uranium spike CRMs are available. From 2010-2012, the JRC-IRMM performed successfully an inter-calibration campaign on selected plutonium spike CRMs, not only to confirm their long-term stability but also to demonstrate the JRC-IRMM's measurement capabilities. The next logical step was to carry out a similar approach on a number of uranium spike CRMs on a metrological basis applying state-of-the art measurement procedures. This enabled the setup of an inter-calibration campaign inter-linking selected 233U, 235U and 236U spike CRMs. The aim of this campaign was to confirm their certified values for quality control purposes and to demonstrate the measurement capabilities for uranium analysis via external quality tools. This was achieved by using some of these uranium CRMs for IDMS measurements of EQRAIN certified test samples and IAEA large-size dried spikes. In this paper the obtained results will be presented and discussed.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard