Preparation and Certification of IRMM-075

A set of 6 new synthetic mixtures with n(236U)/n(238U) isotope ratios varying from 10-4 to 10-9 has been prepared and certified. Natural uranium with low 236U isotope abundance and enriched 236U were both purified using well proven chemical methodology extensively tested in the preparation of other uranium synthetic mixtures such as IRMM-074. The purification involved separation on anion and cation columns followed by precipitation as peroxide. Manipulations were carried out in separate new glove-boxes to avoid cross contamination. The oxides were sintered into U3O8 in an oven installed in a glove-box with controlled humidity. Primary solutions of the same concentration were prepared by dissolving the oxides of 236U and natU. From the 236U solution four dilutions were made by weighing. Weighed amounts of the dilutions of 236U and weighed amounts of natU were mixed to form a set of 236U/238U mixtures at a concentration of 1 mg U*g-1. The final solutions were dispensed into quartz ampoules which were subsequently flame sealed. Verification of the mixtures IRMM-075/1-7 was performed by TRITON TIMS measurements using Faraday collectors and secondary electron multiplier in combination with an RPQ energy filter for improved abundance sensitivity. The results agreed well with the certified values obtained from the mixing calculations. The uncertainties contributing to the final uncertainties of the isotopic ratios are the weighing errors, the measured impurities in each starting material, the stoichiometry of the oxides and the isotopic abundances of each. The method for the preparation and mixing are described and the certification and verification procedures are reported.JRC.D.4-Isotope measurement

Certification Report of EQRAIN Plutonium - Program N° 10

The EQRAIN Plutonium N° 10 is an evaluation program set up by CEA/CETAMA in order to evaluate the quality of results from nuclear measurement laboratories. The objective of this programme is to determine the plutonium concentration of a plutonium nitrate solution. Three ampoules were sent to each participant. At the IM/nuclear group, it was decided to analyse both of the EQRAIN N° 10 samples, H53 and H91. The results of this exercise would possibly enable us to identify problems occuring during the handling and measurements by mass spectrometric isotope dilution analysis (IDMS) of Pu. The evaluation of the mass-spectrometry analysis as part of this program could indicate unexplained processes such as the behaviour of the fractionation factor and outlier results not identified during measurements.JRC.D.4-Isotope measurement

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 the Isotopic Reference Material IRMM-049d

A highly enriched 242Pu Isotopic Reference Material (IRMM-049d) has been prepared and certified for the 242Pu isotope amount content. The certified value of 3.666 8(18) x 10-7 mol 242Pu per g of solution was established by Isotope Dilution Mass Spectrometry (IDMS). The plutonium isotopic composition was determined by Thermal Ionization Mass Spectrometry (TIMS) and calibration of these measurements by means of synthetic mixtures. The IRMM-049d Isotopic Reference Material is supplied in a glass ampoule with a screw cap seals containing about 10 mL of 5 mol x L-1 nitric acid with plutonium. The content of each vial is approximately 1 mg 242Pu. This Isotopic Reference Material is the product of a systematic IRMM programme to supply Isotopic Reference Materials of various isotopes at different concentrations.JRC.D.2-Reference material

Preparation and Certification of IRMM-3636, IRMM-3636a and IRMM-3636b

Isotope reference materials IRMM-3636 was prepared by gravimetrically mixing of solutions from highly enriched 99.96% 233U (IRMM-3630) and highly enriched 99.97% 236U (IRMM-3660) in order to obtain an isotopic ratio n(233U)/n(236U) close to unity. IRMM-3636a and IRMM-3636b were prepared from IRMM-3636 by gravimetrical dilution. The primary solution, IRMM-3636 is for the time being not yet available for external users. The certified isotope content values for IRMM-3636a of 4.27988(54)*10-7 mol U per g of solution and for IRMM-3636b of 2.21802(61)*10-8 mol U per g of solution and the certified isotope amount ratios have been established by mass metrology, subsequently the primary solution IRMM-3636 was verified by isotope mass spectrometry. The methodology used in the preparation and certification was similar to that of comparable uranium mixtures made in the past. The uncertainties contributing to the final uncertainties of the isotopic ratios are the weighing errors, the measured impurities in each starting material, the stoichiometry of the oxides and the isotopic abundances of each of the starting materials. The method for the preparation and mixing is described and the certification and verification procedures are reported. Verification of IRMM-3636 was performed by TRITON TIMS measurements using Faraday collectors and secondary electron multiplier in combination with an RPQ energy filter for improved abundance sensitivity. The results agreed well with the certified values obtained from the mixing calculations. By mixing the n(233U)/n(236U) double spike with a sample and applying internal mass fractionation correction, the n(235U)/n(238U) ratio of a given sample can be determined with the highest possible accuracy. The Isotopic Reference Materials IRMM-3636, IRMM-3636a and IRMM-3636b are part of a systematic IRMM programme to supply Isotopic Reference Materials of various isotopes at different concentrations. The Isotopic Reference Material is supplied in a sealed quartz ampoule containing 1 mL of a 1 M nitric acid solution.JRC.D.4-Isotope measurement

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

Preparation and Certification of IRMM-1027j, Large-Sized Dried (LSD) Spike

A new set of Large Size Dried (LSD) Spikes for the determination of uranium and plutonium by isotope dilution mass spectrometry in solutions of spent fuel from reprocessing plants has been prepared and certified for uranium and plutonium isotopic contents. The methodology followed was similar to that of previous batches. The solution, made by dissolution of the starting materials in nitric acid, was dispensed directly into individual penicillin vials. This new batch of large size dried spikes contains ca. 50 mg of uranium (235U abundance = 19.7%) and ca. 1.8 mg of plutonium (239Pu abundance = 97.8%) in each individual vial, covered with a light layer of organic material (cellulose acetate butyrate) as stabilizer. The U and Pu amount content was certified based on values from mass metrology. Verification of the amount contents of the spike was done by IDMS at IRMM. The values measured for the batch solution and of the dried covered spikes agreed well with those calculated from the weights of starting materials dissolved and the weights of the final solution.JRC.D.4-Isotope measurement

Preparation and Verification of QUAD Uranium Isotopic Reference Material IRMM-3100a

The isotopic reference material IRMM-3100a was prepared by gravimetrical dilution of IRMM-3101. The primary solution IRMM-3101 was designed such that the material consists of equivalent parts of four individual isotopes n(233U)/n(235U)/n(236U)/n(238U) with a ratio of one. The certified isotope amount ratio for ratio n(233U)/n(236U) has been established by mass metrology and was verified by isotope mass spectrometry. The certified ratios n(234U)/n(236U), n(235U)/n(236U) and n(238U)/n(236U) have been measured by TIMS in multi-dynamic mode and using the n(233U)/n(236U) ratio for internal normalization. The preparation of IRMM-3101 is in full described elsewhere. [1] The Isotopic Reference Material IRMM-3100a is part of a systematic IRMM programme to supply Isotopic Reference Materials of various isotopes at different concentrations. The Isotopic Reference Material is supplied in a quartz ampoule containing 0.5 mL of a 1 M nitric acid solution.JRC.DG.D.2-Reference material

Preparation and Certification of IRMM-1027k, Large-Sized Dried (LSD) Spike

The concept of directly spiking samples of the solution with dissolved irradiated nuclear fuel for later dilution and measurement of the isotopic contents of uranium and plutonium has been developed successfully. Large sized dried spikes (LSD) have become a fundamental part of the fissile material control of irradiated nuclear fuel. In the frame of providing these spikes to the nuclear industry, a new set of LSD Spikes for the determination of uranium and plutonium by isotope dilution mass spectrometry in solutions of spent fuel from reprocessing plants has been prepared and certified for uranium and plutonium isotopic contents. The methodology followed was comparable to that of previous batches. The solution, made by dissolution of the starting materials in nitric acid, was dispensed directly into individual penicillin vials. However in this campaign an automated system was introduced to dispense and weigh the majority of vials. At the same time the system was validated by comparing the results with those of the traditional syringe dispensing and substitution weighing. This new batch of large size dried spikes contains ca. 50 mg of uranium (235U abundance = 19.1%) and ca. 1.8 mg of plutonium (239Pu abundance = 97.8%) in each individual vial, covered with a light layer of organic material (cellulose acetate butyrate) as stabilizer. The U and Pu amount content was certified based on values from mass metrology of the validated automated system or from the manual weighings. Verification of the amount contents of the spike was done by IDMS at IRMM. The values measured for the batch solution and of the dried covered spikes agreed well with those calculated from the weights of starting materials dissolved and the weights of the final solution.JRC.D.4-Isotope measurement

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