Preparation and certification of Large-Sized Dried (LSD) Spike - IRMM-1027v : certified reference material for the masses of 239Pu, 235U, 238U and Pu and U isotope amount ratios.
Date: 2021-09-16
Institutions: Joint Research Centre
Subjects: approval, nuclear fuel, nuclear research, research method, research report

CERTIFICATION REPORT 

Preparation and Certification of Large-Sized Dried 
(LSD) Spike: IRMM-1027v 

Certified reference material for the 
masses of 239Pu, 235U, 238U and Pu 
and U isotope amount ratios 

Toth, K., Jakopic, R., Bujak, R., Bauwens, J., Hennessy, C., 
Kehoe, F., Jakobsson, U., Richter, S., Aregbe, Y.  

2021 

EUR 30759 EN 

 
 
 
  
 
 
 
 
 
This publication is a Reference Materials report by the Joint Research Centre (JRC), the European Commission’s 
science and knowledge service. It aims to provide evidence-based scientific support to the European policymaking 
process. The scientific output expressed does not imply a policy position of the European Commission. Neither 
the  European Commission  nor  any  person  acting  on  behalf  of  the  Commission  is responsible for  the  use  that 
might be made of this publication. For information on the methodology and quality underlying the data used in 
this publication for which the source is neither Eurostat nor other Commission services, users should contact the 
referenced source. The designations employed and the presentation of material on the maps do not imply the 
expression  of  any  opinion  whatsoever  on  the  part  of  the  European  Union  concerning  the  legal  status  of  any 
country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. 

Contact information 
Name: Kalman Toth; Yetunde Aregbe 
Address: Joint Research Centre, Retieseweg 111, 2440 Geel, Belgium 
Email: kalman.toth@ec.europa.eu; yetunde.aregbe@ec.europa.eu  
Tel.: + 32 (0) 14 571 963 ; + 32 (0) 14 571 673 

EU Science Hub 
https://ec.europa.eu/jrc 

JRC125500 

EUR 30759 EN 

PDF 

ISBN 978-92-76-40041-7 

ISSN 1831-9424 

doi:10.2760/59260 

Luxembourg: Publications Office of the European Union, 2021 

© European Atomic Energy Community, 2021 

The reuse policy of the European Commission is implemented by the Commission Decision 2011/833/EU of 12 
December 2011 on the reuse of Commission documents (OJ L 330, 14.12.2011, p. 39). Except otherwise noted, 
the reuse of this document is authorised under the Creative Commons Attribution 4.0 International (CC BY 4.0) 
licence (https://creativecommons.org/licenses/by/4.0/). This means that reuse is allowed provided appropriate 
credit is given and any changes are indicated. For any use or reproduction of photos or other material that is not 
owned by the EU, permission must be sought directly from the copyright holders. 

All content © European Atomic Energy Community 2021 

How to cite this report:  Toth, K. et al, Preparation and Certification of Large-Sized Dried (LSD) Spike:-IRMM-
1027v Certified reference material for the masses of  239Pu, 235U, 238U and Pu and U isotope amount ratios, EUR 
30759  EN,  Publications  Office  of  the  European  Union,  Luxembourg,  2021,  ISBN  978-92-76-40041-7,  doi: 
10.2760/59260, JRC125500 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Contents 

Contents ................................................................................................................................. 3 

Acknowledgement .................................................................................................................... 5 

Abstract ................................................................................................................................. 6 

1. 

Introduction ..................................................................................................................... 9 

1.1 Background............................................................................................................... 9 
1.2 Choice of the material ................................................................................................. 9 
1.3 Design of the project ................................................................................................... 9 
2.  Participants ................................................................................................................... 10 

3.  Material processing and process control ............................................................................ 10 

3.1 Origin and purity of the starting material ........................................................................ 10 
3.2 Processing .............................................................................................................. 10 
3.3 Process control ........................................................................................................ 13 
4.  Homogeneity .................................................................................................................. 13 

4.1 Between-unit homogeneity ......................................................................................... 13 
4.2 Homogeneity of the U and Pu isotope ratios .................................................................... 16 
4.3 Minimum sample intake ............................................................................................. 16 
5.  Stability ......................................................................................................................... 16 

5.1 Short-term stability ................................................................................................... 16 
5.2 Long-term stability ................................................................................................... 19 
6.  Characterisation ............................................................................................................. 19 

6.1 Purity of the starting materials .................................................................................... 19 
6.2 Masses of 235U, 238U, 239Pu , U and Pu isotope amount ratios and their uncertainties ................... 20 
6.3 Weighing and associated uncertainties ........................................................................... 21 
6.4 Isotope ratio confirmation measurements ........................................................................ 21 
6.5 Amount content confirmation measurements ................................................................... 24 
7.  Value Assignment ........................................................................................................... 28 

7.1 Certified values and their uncertainties ........................................................................... 28 
8.  Metrological traceability and commutability ....................................................................... 28 

8.1 Metrological traceability ............................................................................................. 28 
8.2 Commutability ......................................................................................................... 29 
Instructions for use ......................................................................................................... 29 

9. 

9.1 Safety information ................................................................................................... 29 
9.2 Storage conditions .................................................................................................... 29 
9.3 Instructions for use ................................................................................................... 29 
9.4 Minimum sample intake ............................................................................................. 29 
9.5 Use of the certified value ........................................................................................... 29 
10.  Conclusions .................................................................................................................... 30 

References ............................................................................................................................ 31 

3 

 
List of abbreviations and definitions ........................................................................................ 33 

List of figures ....................................................................................................................... 35 

List of tables ......................................................................................................................... 37 

Annexes ................................................................................................................................ 38 

4 

 
Acknowledgement 

The authors would like to thank: 

the experts of the Certification Advisory Panel: Sébastien Picart, Commissariat à l'Energie Atomique et aux Energies Alternatives 
(CEA), France; Thomas  Prohaska,  Montanuniversität Leoben, Austria; Jochen Vogl,  Bundesanstalt für Materialprüfung (BAM), 
Germany, for reviewing the certification report. 

Rüdiger Kessel, Metrodata GmbH, Germany, for discussions on GUM, GUM WB and related topics. 

David Vanleeuw, Goedele Sibbens, Viktor Jobbágy, JRC G.2., Belgium, for alpha spectrometry measurements. 

Saskia Werelds, JRC G.2., Belgium, for her technical assistance throughout the project, Theo Drooghmans, JRC G.2., Belgium, 
and Marleen van Bocxstaele, JRC F.1., Belgium, for arrangements in the transport of the CRM material. 

Mika Sumi, Urska Repinc from the IAEA-SGAS, Austria and Evelyn Zuleger, Ana Maria Sanchez Hernandez, Karin Casteleyn and 
the  JRC  G.II.6.  and  JRC  G.II.8  analytical  service  from  the  JRC-Karlsruhe,  Germany  for  carrying  out  external  verification 
measurements on the selected units of the IRMM-1027v LSD spikes. 

Authors 

Kálmán Tóth, Rožle Jakopič, Renáta Buják, Jeroen Bauwens, Carmel Hennessy, Frances Kehoe, Ulf Jakobsson, Stephan Richter 
and Yetunde Aregbe. 

European Commission, Joint Research Centre, Directorate G - Nuclear Safety and Security, G.2 – Standards for Nuclear Safety, 
Security and Safeguards, Geel, Belgium 

5 

 
 
 
Abstract 

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  30  years  [1].  This  report  describes  the 
preparation and certification of a new batch of LSD spikes. IRMM-1027v is a dried mixture of uranyl- and plutonium nitrate in 
cellulose acetate butyrate with dioctyl phthalate (CAB/DOP) or carboxymethyl cellulose (CMC). The material is certified for the 
masses of 235U, 238U and 239Pu 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 [2]. The homogeneity and stability was assessed in 
accordance with ISO Guide 35:2017 [3] and the uncertainties of the certified values were calculated in accordance with Guide 
to the Expression of Uncertainty in Measurement (GUM) [4]. 

The certified reference materials uranium metal EC NRM 101, enriched uranium metal NBL PO CRM 116-A and plutonium metal 
CETAMA MP2 were used as starting materials to prepare the mother solution. This solution was dispensed into individual vials 
by means of an automated robot system and subsequently evaporated to dryness. A solution of an organic substance either 
cellulose acetate butyrate with dioctyl phthalate (CAB/DOP) or carboxymethyl cellulose (CMC) was added to the spike material, 
evaporated and dried. The organic matrix serves as a stabiliser to retain the dried nuclear material at the bottom of the vial. In 
total, 905 units were produced. 

The heterogeneity of the batch was estimated based on the between-unit standard deviation and stability during dispatch and 
storage was assessed in accordance with ISO Guide 35:2017 [3]. 

The certified values were obtained from the gravimetric preparation of the mother solution, taking into account the mass, purity 
and isotopic composition of the starting materials, the mass of the mother solution, and the mass of an aliquot in each individual 
unit.  The  certified  and  indicative  values  with  the  exception  of  the  233U  values  were  confirmed  by  isotope  dilution  thermal 
ionisation  mass  spectrometry  (ID-TIMS),  thermal  ionisation  mass  spectrometry  (TIMS)  and  the  n(238Pu)/n(239Pu)  by  alpha 
spectroscopy as independent methods on randomly selected units of IRMM-1027v or the mother solution.  

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 54 mg of uranium with a relative mass 
fraction m(235U)/m(U) of 19.2 % and 1.8 mg of plutonium with a relative mass fraction  m(239Pu)/m(Pu) of 97.8 % as dried 
nitrates in CAB/DOP or CMC.  

The whole amount of sample per unit has to be used.  

The following values were assigned: 

Isotope amount ratios 

n(234U)/n(238U) 

n(235U)/n(238U) 

n(236U)/n(238U) 

n(238Pu)/n(239Pu) 

n(240Pu)/n(239Pu) 

n(241Pu)/n(239Pu) 

n(242Pu)/n(239Pu) 

Certified value 1) 
 [mol/mol] 

0.0027807 

0.242509 

0.0022322 

0.00002787 

0.0224103 

0.0001279 
0.00007573 

Uncertainty 2) 
 [mol/mol] 

0.0000023 

0.000035 

0.0000018 

0.00000026 

0.0000051 

0.0000017 

0.00000078 

The certified masses and the uncertainties of 235U, 238U and 239Pu per unit are listed in Annex 1 for each individual unit. 

1) The certified values are traceable to the values on the respective metal certificates (EC NRM 101, NBL PO CRM 116-A and CETAMA MP2, 
Annexes 2-7) and consequently either partly to the SI or to the national metrology data base for the United States. The reference date for 
the plutonium and uranium isotope amount ratios is November 1, 2019. 

2) The reference material was produced in compliance with ISO/IEC 17034:2016 and certified in accordance with ISO Guide 35:2017. The 
uncertainty of the certified value is the expanded uncertainty with a coverage factor k = 2 with the exception of n(235U)/n(238U) ratio value, 
which has a coverage factor k = 2.2 based on the t-distribution for the associated effective degrees of freedom (dfeff = 13). The expanded 
uncertainties correspond to a level of confidence of about 95 % estimated in accordance with ISO/IEC Guide 98-3:2008:2008, Guide to 
the Expression of Uncertainty in Measurement (GUM:2008). 

The atomic masses of radionuclides were obtained from M. Wang et al. [5]  

6 

 
 
 
The half-lives of radionuclides were obtained from DDEP-BIPM (Table of radionuclides) [6] and R. Wellum et al. [7]. 

The following values for uranium and plutonium isotopic mass fraction, amount content, mass fraction and isotope  amount 
ratios for the nitrate solution of IRMM-1027v were also assigned as indicative values: 

Indicative Values 

Isotope amount ratio 

Indicative value 2) 
[mol/mol] 

0.0000000909 

Uncertainty 3) 
[mol/mol] 

0.0000000020 

Isotope mass fraction (·100) 

Indicative value 2) 
[g/g] 

0.00000715 
0.21970 
19.2420 
0.17787 
80.3604 
0.002713 
97.77680 
2.20039 
0.01261 
0.007497 

Uncertainty 3) 
[g/g] 

0.00000016 
0.00018 
0.0023 
0.00014 
0.0023 
0.000026 
0.00052 
0.00049 
0.00016 
0.000077 

Amount content 

Value 2) 4) 
[μmol/g solution] 

Uncertainty 3)  
[μmol/g solution] 

17.6059 
72.5990 
90.5688 
2.9680 
3.0352 

Value 2) 4) 
[mg/g solution] 

4.13817 
17.28224 
21.5059 
0.70950 
0.72564 

Mass fraction 

0.0025 
0.0039 
0.0045 
0.0012 
0.0012 

Uncertainty 3)  
 [mg/g solution] 
0.00059 
0.00092 
0.00011 
0.00029 
0.00029 

n(233U)/n(238U)1) 

m(233U)/m(U)1) 4) 
m(234U)/m(U)4) 
m(235U)/m(U)4) 
m(236U)/m(U)4) 
m(238U)/m(U)4) 
m(238Pu)/m(Pu)4) 
m(239Pu)/m(Pu)4) 
m(240Pu)/m(Pu)4) 
m(241Pu)/m(Pu)4) 
m(242Pu)/m(Pu)4) 

235U 
238U 
U 
239Pu 
Pu 

235U 
238U 
U 
239Pu 
Pu 

1) The n(233U)/n(238U) isotope amount ratio and m(233U)/m(U) isotope mass fraction values could not be verified because it is below the detection 
limit of the ID-TIMS. 

2) Indicative values are values that refer to the nitrate solution and are derived from the certified values with the exception of n(233U)/n(238U) isotope 
amount ratio. Therefore, they are also traceable to the values on the respective metal certificates (EC NRM 101, NBL PO CRM 116-A and CETAMA 
MP2) and consequently either partly to the SI or to the national metrology data base for the United States. The reference date for the plutonium 
and uranium isotopic mass fraction, amount content, mass fractions and isotope amount ratios of the mother solution of IRMM-1027v is November 
1, 2019. 

3) The reference material was produced in compliance with ISO/IEC 17034:2016 and certified in accordance with ISO Guide 35:2017. The uncertainty of 
the indicative value is the expanded uncertainty with a coverage factor k = 2 with the exception of n(233U)/n(238U) and m(233U)/m(U) values, which 

7 

 
 
 
 
 
 
 
 
 
has a coverage factor k = 3.1 (dfeff = 3), 235U amount content and mass fraction values, which have a coverage factor k = 2.3 (dfeff = 9) and the 
235U and 238U isotope mass fraction values which have a coverage factor k = 2.2 (dfeff = 13) based on the t-distribution for the associated effective 
degrees of freedom. The expanded uncertainties correspond to a level of confidence of about 95 % estimated in accordance with ISO/IEC Guide 98-
3:2008, Guide to the Expression of Uncertainty in Measurement (GUM:2008). 

4) Isotope mass fraction is expressed as (xxxU/Utot)x100 and (xxxPu/Putot)x100. 

5) Nitrate solution before dispensing, drying and application of CAB/DOP or CMC. 

The atomic masses of radionuclides were obtained from M. Wang et al. [5]  

The half-lives of radionuclides were obtained from DDEP-BIPM (Table of radionuclides) [6] and R. Wellum et al. [7]. 

8 

 
 
 
 
1.  Introduction  

1.1 Background 

The International Target Values for Measurement Uncertainties in Safeguarding Nuclear Materials (ITVs) are uncertainties to be 
considered in judging the reliability of the measurement results of analytical techniques applied to industrial nuclear and fissile 
materials, which are subject to safeguards verification. ITVs should be achievable under the conditions normally encountered in 
typical industrial laboratories or during actual safeguards inspections. In 2010, the International Atomic Energy Agency (IAEA) 
together  with  the  European  Safeguards  Research  and  Development  Association  (ESARDA),  international  standardisation 
organisations and regional safeguards authorities published a revised version of the ITVs [8]. The ITVs-2010 are intended to be 
used by nuclear plant operators and safeguards organisations as a reference of the quality of measurements necessary for 
nuclear  material  accountancy.  Currently  these  international  target  values  are  revised  by  the  IAEA  jointly  with  experts  from 
respective stakeholder domains towards the release of the ITVs-2020.   

The  series  of  IRMM-1027  Large-Sized  Dried  (LSD)  spikes  were  prepared  by  the  Joint  Research  Centre  of  the  European 
Commission  (EC-JRC)  to  meet  the  existing  requirements  for  reliable  isotope  reference  materials  for  the  accountancy 
measurements of uranium and plutonium by isotope dilution mass spectrometry (IDMS) in compliance with the ITVs-2010 in 
spent nuclear fuel. These spikes contain relatively large amounts of uranium and plutonium (about 55 mg U and 2 mg Pu), 
isotopically different from the uranium and plutonium in the test sample and are in dried nitrate form. Approximately 1000 
units  of  IRMM-1027  LSD  spikes  are  prepared  annually  to  fulfil  the  demands  for  fissile  material  control  from  European 
Safeguards Authorities and industry [9, 10]. 

1.2 Choice of the material 

The IRMM-1027v batch of LSD spikes was prepared from natural uranium (EC NRM 101), enriched uranium (NBL PO CRM 116-
A) and plutonium (CETAMA MP2) certified reference metals (Annex 2-Annex 6). Each unit of IRMM-1027v contains about 54 mg 
of uranium with a relative isotope mass fraction m(235U)/m(U) of 19.2% and 1.8 mg of plutonium with a relative isotope mass 
fraction m(239Pu)/m(Pu) of 97.8 %. The relative isotope mass fraction m(235U)/m(U) is below 20 %, thus the uranium is classified 
as "low enriched" for accountability purposes. 

Individual units are certified for the mass of 239Pu, 235U and 238U and for the plutonium and uranium isotope amount ratios. The 
uranium and plutonium amount content and mass in a single IRMM-1027 LSD spike is such that no dilution of a typical sample 
of dissolved nuclear fuel to be analysed is needed prior to measurement. As the dried nitrates could flake off the vial surface 
over time or during transport, an organic polymer is added to retain the material at the bottom of the tailor-made headspace 
vial, in the following referred to as “penicillin vial”, supplied by Euro-Scientific, Belgium. 

From the batch  IRMM-1027f  [11] to the batch IRMM-1027s  [12], the  cellulose acetate butyrate (CAB)  has been  used  as  a 
stabilising material for the IRMM-1027 LSD spikes for transport, thus for short-term stability purposes. The CAB produces a 
stable layer at the bottom of the vial and guarantees the integrity of the LSD spikes for about 3 years [13]. Customers, however, 
require a longer shelf-life of IRMM-1027 LSD spikes, hence JRC-Geel and JRC-Karlsruhe joined their forces to investigate new 
stabilizing matrices in the framework of the Innovative Nuclear Reference Materials for  EURATOM Safeguards and Industry 
(INS-CRM) exploratory research project [14]. The main objective of the project was to find potential materials that would prolong 
the shelf-life of LSD spikes from 3 to 5 years or even beyond. The new coatings should fulfil additional requirements such as 
ready  dissolution  in  nitric  acid  and  a  lack  of  interference  with  chemical  separations  or  mass  spectrometry  measurements. 
Among the tested materials, carboxymethyl cellulose (CMC) has shown very promising results [15, 16]. Hence it was applied 
from the batch IRMM-1027t onwards [17]. 

As a result of the successful outcome of the exploratory research project and the real application on the IRMM-1027t and u 
[18] LSD spikes, the same approach was applied when preparing the IRMM-1027v spikes. Thus, they were coated with either 
CMC or CAB/dioctyl phthalate (DOP) material.  

1.3 Design of the project 

The  mother  solution  was  prepared  gravimetrically  by  dissolving  uranium  and  plutonium  certified  reference  metals  in 
hydrochloric and nitric acid. Finally, the dried nitrates were treated with CAB/DOP or CMC for preservation during storage and 
transport. The individual units of IRMM-1027v LSD spikes were prepared by dispensing aliquots (about 2.5 g) of the mother 
solution into penicillin  vials and  were evaporated to dryness at  around 55°C, under glovebox conditions (~50mmHg under-
pressure).  

The certified masses of plutonium and uranium isotopes and the certified values of the uranium and plutonium isotope amount 
ratios are based on the data from the weighing certificates and the certificates of the starting materials (metals). Confirmation 
measurements  and  homogeneity  assessment  were  established  by  IDMS  on  randomly  selected  vials.  For  this  project,  the 

9 

 
confirmation measurements were performed on units that were spiked with IRMM-046c. The homogeneity assessment was 
performed on the same, single spiked units (IRMM-046c) that were used for the confirmation measurements. A mixed, in-house 
prepared 235U and 239Pu quality control reference material was measured on the same ID-TIMS turret with each verification set 
of IRMM-1027v. 

2.  Participants 

Project management and evaluation, processing, homogeneity study, stability study and characterisation  were performed at 
the European Commission, Joint Research Centre, Directorate G  – Nuclear Safety and Security, G.2  - Standards for Nuclear 
Safety, Security and Safeguards in Geel, Belgium. 

3.  Material processing and process control 

3.1 Origin and purity of the starting material 

CRMs of high purity metals of uranium (EC NRM 101, Geel, Belgium and NBL PO CRM 116-A, Lemont, USA) and plutonium 
(CETAMA MP2, CEA Marcoule, France) were used as starting materials (Figure 1) for the preparation of the IRMM-1027v LSD 
spikes. The isotopic composition and the purity of the metals are given in Annex 2 - Annex 7. 

Figure 1 Starting materials for the preparation of IRMM-1027v LSD spikes: a) one of the electropolished Pu MP2 metal 
b) etched U NBL PO CRM 116-A metal and c) U EC NRM 101 metal (Source: EC JRC G.2) 

a) 

b) 

c) 

3.2 Processing 

Dissolution of the Pu metal 

The protocol in use at JRC-Geel for the dissolution of Pu MP2 metal consists in applying an electro-polishing of the Pu metal 
before the weighing and dissolution of the metal [12]. It has to be mentioned, that this protocol does not comply with MP2 
certificate and associated recommendation for use as the mass of the MP2 ingot is certified (see Annex 5).  

For the IRMM-1027v batch, after electro-polishing the 3 selected units of the MP2 metal, the metals were rinsed with deionised 
water and acetone (p.a., Merck, Darmstadt, Germany) and dried. Then the units were precisely weighed (by substitution method) 
in a dedicated glove-box on a Mettler Toledo AT 261 DR balance (readability = 0.1/0.01mg) and subsequently transferred to 
another glove box for dissolution. They were dissolved in about 20-25 mL of hydrochloric acid (c = 6 mol L-1, Suprapur®, Merck). 
The reaction was vigorous and fast and no visible remaining Pu metal was left. Then, nitric acid solution (c = 8 mol L-1, p.a., 
Merck) was added to the dissolved Pu solution. The flask with the plutonium solution was closed with a stopper and kept in a 
dedicated glove box to prevent any potential contamination. The dissolution of Pu MP2 metal is shown in Figure 2. 

Dissolution of the U metals  

The respective units of enriched uranium metal (NBL PO CRM 116-A) and natural uranium metal (EC NRM 101) were weighed 
(by substitution method) on a Mettler Toledo XPE 205 balance (readability = 0.01mg) and added into the prepared plutonium 
solution. Prior to weighing, the units of NBL PO CRM 116-A metal were etched with nitric acid (c = 8 mol L-1) to remove surface 
oxidation products as described in the certificate, and subsequently rinsed with deionised water and acetone (p.a., Merck) and 
dried, according to the manufacturer’s recommendation. The units of the EC NRM 101 uranium metal were weighed as provided 
without any cleaning (see Figure 1c), as the material was sealed in a glass ampoule under inert atmosphere. The final amounts 
of concentrated nitric acid and deionised water were added to adjust the concentration of the nitric acid solution (c = 5-6 mol 
L-1). The solution was left to homogenise for a few days with occasional swirling by hand, and it was weighed to determine the 
final  mass  of  the  mother  solution  on  a  Mettler  Toledo  PR  5002  balance  (readability  =  0.01g),  considering  the  necessary 
corrections for air buoyancy effects. The dissolution of the uranium metals is shown in Figure 2. 

10 

 
  
  
 
The conventional mass values of most the weights used for the mass determination of the metals and the mother solution 
were in accordance with the maximum permissible error of class E2 according to OIML-R 111:2004 [19]. The conventional mass 
values  of  some  of  the  larger  weights  were  in  accordance  with  the  maximum  permissible  error  of  class  F1.  More  detailed 
information on the weights is available upon request. 

Prior to dispensing the mother solution into individual penicillin vials, 4 aliquots were analysed by isotope dilution (ID) technique 
on  a  TRITON  thermal  ionisation  mass  spectrometer  (TIMS,  Thermo-Fisher,  Bremen,  Germany)  to  verify  the  gravimetrically 
determined amount contents of plutonium and uranium. Additionally, four aliquots were analysed by TIMS to verify the uranium 
and plutonium isotope amount ratios (see Section 3.3 Process Control). 

Figure 2 Dissolution of Pu and U metals: a) MP2 dissolution in HCl, b) flask from 2a after adding HNO3 and U NBL PO 
CRM 116-A, c) flask from 2b after adding U EC NRM 101 (Source: EC JRC G.2) 

a) 

b) 

c) 

Dispensing, drying and application of CAB/DOP and CMC  

Dispensing and weighing of the mother solution into individual penicillin vials were performed by a validated automated system, 
which was installed at the JRC Geel in collaboration with Nucomat (Lokeren, Belgium) [20]. The major components of the system 
are a robot, two balances and a dispenser. The robot is software driven and designed to control all movements inside the glove 
box, such as identifying the vial with a barcode reader, dispensing and weighing of an aliquot of the solution (2.5 g) into the 
penicillin vials. The weighing component is equipped with an analytical balance (Sartorius TE124S, Göttingen, Germany) and a 
5 kg balance (Sartorius TE6101, Göttingen, Germany) to monitor the mass of the mother solution during dispensing. The whole 
solution  (about  2.35  kg)  was  dispensed  into  911  vials  over  five  consecutive  working  days.  912  units  can  be  found  in  the 
certificate of dispensing (Annex 11) however, one vial was excluded from the certification process due to barcode failure and 
six units due to splashing during dispensing or before drying. Therefore, a total number of 905 units were certified. 

The drying of the dispensed solution contained in the vials was carried out on a hot plate. The temperature of the solution was 
kept below 60 °C for several days (typically 4-5 days continuous heating) to evaporate the solution completely.  

For the IRMM-1027v LSD spikes, two organic matrices were used: a) 465 units were prepared with CAB containing a plasticizer 
dioctyl phthalate (DOP) and b) 440 units were prepared with CMC. The number of units prepared with the two different coating 
corresponds to the customers’ needs.  

a) CAB/DOP protocol 

After evaporation to dryness, about 0.7 mL of CAB/DOP solution in acetone was added. CAB/DOP solution was prepared by 
dissolving 10 g CAB (35-39 g/100 g butyryl content, Acros, New Jersey, USA) and 2 g DOP (Sigma-Aldrich, Merck) in 88g acetone. 
The CAB/DOP solution in the vials was evaporated at room temperature and then heated to about 45 °C to dry completely. 
Three dedicated glove boxes were used for drying and CAB/DOP application, allowing the preparation of up to 48 units per day 
in one glove box. The vials were closed with stoppers and aluminium caps, sealed in PVC packages and labelled. 

b) CMC protocol 

10 g of low viscosity carboxymethyl cellulose (CMC) sodium salt (Merck, Darmstadt, Germany) was slowly added into 90 g of 
nitric acid solution (c = 2 mol L-1, p.a., Merck, Darmstadt, Germany) at 70-75 °C under continuous stirring. The mixture was 
stirred and heated until the dissolution of CMC was complete (usually 2-3 hours) and then allowed to cool to room temperature. 
A colourless to slightly yellow, transparent solution was obtained. 1.5 mL of this solution was added to the dried nitrates and 
heated up to about 52-54 °C. The solution in the vials was kept at this temperature to evaporate the nitric acid solution. Once 
the nitric acid had evaporated completely and the foams were produced, the vials were removed from the hotplate, cooled and 
closed with butyl rubber caps. This protocol allows the preparation of up to 24 units per day in one glove box. 

CAB/DOP or CMC were added to retain the dried material at the bottom of the penicillin vials in order to resist physical shocks 
that  might  be  encountered  during  transport  and  to  avoid  flaking  of  the  material  during  long-term  storage.  Both  cellulose 
matrixes dissolve readily in warm nitric acid and have no effect on the subsequent IDMS analysis.  

11 

 
 
 
 
 
One example each of IRMM-1027v LSD spike prepared with CAB/DOP and CMC spikes are shown in Figure 3. The processing 
steps are shown in  

Figure 4. 

Figure 3 Units of IRMM-1027v LSD spike: a) treated with CAB/DOP and b) treated with CMC (Source: EC JRC G.2) 

a) 

b) 

Figure 4 Preparation of IRMM-1027v LSD spikes (Source: EC JRC G.2) 

12 

                      
 
 
 
 
 
3.3 Process control  

This section describes the measurements performed on the mother solution of IRMM-1027v prior to dispensing into vials to 
verify the amount contents of uranium and plutonium in the solution from gravimetric preparation. Detailed GUM Workbench 
calculations  of  the  uranium  and  plutonium  amount  contents,  mass  fractions,  isotopic  compositions  and  their  associated 
uncertainties from the gravimetric preparation of IRMM-1027v are shown in Annex 13 and Annex 14. 

Two aliquots of the mother solution (about 2.5 g each) were individually spiked with a mixed  233U/242Pu spike CRM (ca. 2 g 
IRMM-046c) for ID-TIMS analysis. The certificate of IRMM-046c can be found in Annex 8.  

The U-Pu separation of the samples was performed using anion-exchange columns (Bio-Rad AG1-X4, 100-200 mesh, Bio-Rad, 
Hercules, USA) as described in detail in [21]. 

The ID-TIMS results of the process control measurements for 235U, 238U and 239Pu amount contents in the mother solution of 
IRMM-1027v  were  metrologically  compatible  with  the  values  from  the  gravimetric  preparation,  except  for  one  of  the  two 
aliquots for  238U amount content (Annex 9, Figure 14). Due to technical reasons and limited access to the JRC-Geel nuclear 
laboratories in 2020, repeated ID-TIMS measurement for 238U amount content was not possible. However, the deviating aliquot 
shows a relatively small bias (-0.07%). Furthermore, all 238U amount content confirmation measurements at JRC-Geel on the 
individual units and the external verification measurements carried out by IAEA-SGAS and JRC-KA verified the gravimetrical 
value (Figure 9 and Figure 10). It is also important to note that the uncertainty associated with gravimetrical preparation is very 
small  due  to  the  low  uncertainties  of  the  starting  materials  in  combination  with  a  primary  method  of  measurement  [22]. 
Moreover, IRMM-1027v is certified for the amount contents of each individual vial and not for the amount content of the mother 
solution. The latter are only provided as indicative values in the material`s certificate.  

The CRM 116-A and the NBL-126 reference materials are used in the JRC G.2 laboratory as quality control (QC) materials for 
uranium and plutonium IDMS, respectively. These stock solutions were prepared and verified independently from the IRMM-
1027v mother solution.[23] An aliquot of CRM 116-A and NBL-126 (ID-QC) material solutions were weighed into a vial and this 
mixture was spiked with the IRMM-046c (242Pu/233U) spike CRM, and measured together with the aliquots of the IRMM-1027v 
mother  solution.  One  ID-QC  was  measured  on  the  same  sample  turret  and  the  result  was  used  for  bias  correction  of  the 
corresponding IRMM-1027v mother solution samples (see Section 6.5 for details).  

4.  Homogeneity 

A key requirement for any reference material is homogeneity. In this respect, it is relevant whether the variation between units 
is significant compared to the uncertainty of the certified value but most importantly whether the combined uncertainty remains 
fit for purpose. In contrast to that, it is not relevant if this variation between units is significant compared to the analytical 
variation.  Consequently,  ISO/IEC  17034:2016  [2]  requires  reference  material  (RM)  producers  to  quantify  the  between  unit 
variation. This aspect is covered in between-unit homogeneity studies.  

The within-unit inhomogeneity does not influence the uncertainty of the certified value when the minimum sample intake is 
respected. In case of the IRMM-1027 LSD CRM series, the whole amount of sample per unit is used for analysis. Thus, there is 
no contribution to the combined uncertainty from the within-unit homogeneity. 

4.1 Between-unit homogeneity  

The between-unit homogeneity was evaluated to ensure that the certified values of the CRM are valid for all 905 units of the 
material within the stated uncertainty. 

As it was already shown during the certification of the IRMM-1027t and IRMM-1027u [17, 18], there is no difference between 
the CAB/DOP and CMC covered spikes concerning the certified isotope amount contents. In the course of the certification of 
IRMM-1027v, twelve single spiked units were selected and eleven of them used (due to one technical outlier) to assess the 
homogeneity for the amount content of  235U, 238U and 239Pu using a random stratified sampling scheme covering the whole 
batch  for  the  between-unit  homogeneity  test.  The  number  of  selected  units  for  the  between-unit  homogeneity  study  is  in 
accordance with ISO Guide 35:2017  [3]. 

In this project,  the homogeneity  study and the confirmation measurements were performed on the same set of  units (see 
Section 6). 

The whole amount of sample per unit (equals minimum sample intake) was dissolved. Randomly selected units of IRMM-1027v 
were spiked and dissolved with around 2g of a mixed 233U/242Pu spike CRM (IRMM-046c) in 5M HNO3 solution. The solution was 
evaporated to dryness in the vials. The U-Pu separation was carried out prior to isotope ratio measurements on each unit in the 
same way as for the process control measurements (see Section 3.3). 

13 

 
Each sample was measured in three replicates. Thus three aliquots were taken from the same spiked and separated unit, loaded 
on the filaments and measured on the same turret together with isotopic standards (IRMM-074/10 for U and IRMM-290/A3 for 
Pu) to correct for instrumental mass fractionation. The selected units were measured together with the in-house Isotope Dilution 
(U/Pu) Quality Control sample. This enabled four IRMM-1027v units plus one QC sample to be measured on the same TIMS 
turret on the same day. Three turrets were prepared for uranium and three turrets for plutonium measurements. Therefore, the 
ID-TIMS analysis for all twelve units of IRMM-1027v were performed under intermediate precision conditions. 

The respective fractions of the samples were measured in a randomised manner to be able to separate a potential analytical 
drift from a trend in the filling sequence. The results of the homogeneity study are shown in Annex 10. 

Regression analyses were performed to evaluate potential trends in the analytical sequence as well as trends in the filling 
sequence. A statistically significant downward trend in the 239Pu analytical sequence was found at a confidence level of 95 %. 
However, a significant day-to-day difference was also observed for the amount content of 239Pu that was strongly (correlation 
coefficient = 0.94) and significantly correlated with the analytical sequence. Therefore, the data was first normalised (scaled) 
by the respective day mean and the resulting data did not show any trend at the 95% CL. A statistically significant trend was 
observed in the filling sequence for the  235U isotope amount content. This trend was included in the calculations. Thus, the 
uncertainty of homogeneity contains both the random between-unit variation and the trend in the filling sequence. The trend 
did not inflate significantly the estimation for uncertainty associated with homogeneity as can be seen from Table 1 and the 
material remained fit for purpose. No trends in the filling sequence or the analytical sequence were visible at a confidence level 
of 95 % for the 238U isotope amount content. The data were tested for consistency using the Grubbs outlier test at a confidence 
level of 95 % on the individual results and on the unit means. In the case of 235U amount content, one outlier was detected 
among the individual results however, no technical reason was found to exclude the data thus it was kept and included in the 
evaluation of homogeneity. 

Quantification of between-unit inhomogeneity of U isotope amount contents was accomplished by analysis of variance (ANOVA), 
which can separate the between-unit standard deviation (sbb) from the method intermediate precision (sip). The latter is defined 
as  within-unit  standard  deviation  in  cases  where  the  subsamples  of  the  unit  are  used.  Otherwise,  it  is  defined  as  method 
repeatability because it is an estimation of the standard deviation of the method (IDMS) under repeatability conditions. In case 
of the U isotope amount contents we did not observe significant differences between the between-unit standard deviations 
under repeatability and intermediate precision conditions, whereas the Pu isotope amount content data were normalised by the 
daily means to compensate for the observed significant day-to-day differences. Therefore, the difference between repeatability 
and intermediate precision variances was zero or negligible for all the three major isotopes.  

The one-way ANOVA uses the F-test for comparing multiple group means and checking their equivalence. The test assumes 
that a) the observations are obtained independently and randomly, b) the residuals are normally distributed c) the variances of 
the  populations  (units)  are  equal  (homoscedasticity).  Both  visual  and  statistical  tests  were  performed  to  check  these 
assumptions. The residuals vs fitted values and the Levene’s test was used to check the homoscedasticity assumptions. The 
quantiles of the residuals were plotted against the quantiles of the normal distribution on a normal Q-Q plot to visualize and 
the Shapiro-Wilk test was used to check at the 95% CL the assumption for normality. 

The F-test results of the ANOVA are unimportant for the determination whether the batch is sufficiently homogeneous. Instead, 
the between-unit standard deviation was used to assess the homogeneity of the IRMM-1027v batch in accordance with ISO 
Guide 35 [3]. It is often difficult to prove normality with small  data sets (i.e. 3 replicates/unit) therefore the assumption of 
normality was used even if it could not be proven by statistical tests. The results of all statistical evaluations are given in Table 
1. 

Table 1 Results of the statistical evaluation of the homogeneity studies of the amount content of 235U, 238U and 239Pu 
in IRMM-1027v (Source: EC JRC G.2) 

Trends 1) 

Outliers 2) 

Normality 3) 

Homoscedasticity 4) 

Analytical 
sequence 

Filling 
sequence 

Individual 
results 

235U amount content 

238U amount content 

239Pu amount 
content 

no 

no 

no 

yes 

no 

no 

yes 

none 

none 

Unit means 

none 

Not normal 
(p=6*10-4) 

Ok (p=0.6) 

none 

Normal (p=0.2) 

Ok (p=0.5) 

none 

Normal (p=0.8) 

Ok (p=0.6) 

Linear regression at CL= 95 %  

1) 
2)  Grubb’s test at CL= 95 % 
3) 
4) 

Shapiro-Wilk test at CL= 95 % 
Levene’s test at CL= 95 % 

14 

 
 
 
 
 
It is possible that sip,rel is too high to calculate sbb,rel by classical ANOVA. In these cases, the mean square between units (MSbetween) 
can be smaller than the mean squares within groups (MSwithin), resulting in negative arguments under the square root used for 
the  estimation  of  the  between-unit  variation,  whereas  the  true  variation  cannot  be  lower  than  zero.  In  this  case,  u*
bb,  the 
maximum inhomogeneity that could be hidden by method repeatability (intermediate precision), was calculated as described 
by Linsinger et  al.  [24] and recommended by ISO Guide 35[3]. u*
bb is comparable to the  limit  of detection  of an analytical 
method, yielding the maximum inhomogeneity that might be undetected by the given study setup (alpha risk).  

Relative  method  intermediate  precision  (sip,rel),  relative  between–unit  standard  deviation  (sbb,rel)  and  relative  maximum 
inhomogeneity (u*

bb,rel) were calculated as:  

𝑠𝑖𝑝,𝑟𝑒𝑙 =  

√𝑀𝑆𝑤𝑖𝑡ℎ𝑖𝑛
𝑦̅

Equation 1 

Equation 2 

Equation 3 

MSwithin 

MSbetween 

mean square within-unit from an ANOVA  

mean squares between-unit from an ANOVA 

mean of all results of the homogeneity study 

N 

mean number of replicates per unit 

degrees of freedom of MSwithin  

As a consequence of the intermediate precision conditions, day-to-day effects can occur that could mask the between-unit 
variation. Therefore, the U isotope data were also checked using one way-ANOVA for any significant difference in between-day 
means. The amount content of U isotopes did not show significant day-to-day differences when they were checked with one 
way-ANOVA nor the Tukey boxplot representation showed sign of significant differences (Annex 10). However, the power of the 
F-test of the ANOVA was very low (0.27 and 0.11 for 235U and 238U day-to-day variance check, respectively) that can lead to 
Type II error: failure to reject the null when it is untrue i.e. the failure to reject that the day-to-day group means are equal in 
case they are not equal. Therefore, based solely on the ANOVA output no conclusion regarding to the day-to-day equivalence 
of the U isotope amount content measurements could be drawn. Nevertheless, different approaches (e.g. random effects model 
with REML or nested ANOVA) for the quantification of between unit variances would provide similar values therefore the ANOVA 
results were accepted and no day-to-day differences were assumed.  

The results of the evaluation of the between-unit variation are summarised in Table 2. 

Table 2 Results of the homogeneity studies of the amount content in IRMM-1027v (Source: EC JRC G.2) 

235U amount content 

238U amount content 

239Pu amount content 

Sip,rel

[%] 

0.061 

0.075 

0.026 

sbb,rel  

[%] 

0.021 

0.017 

0.020 

u*

bb,rel

[%] 

0.019 

0.024 

0.008 

Despite  the  trend  in  the  235U  filling  sequence  at  a  95  %  confidence  level  and  the  non-normality  of  residuals,  the  ANOVA 
estimation was accepted because the sbb estimate was very close to the other two isotopes (see Table 2). This is expected when 
a homogeneous solution is used for the CRM batch preparation. Therefore, the between-unit standard deviation can be used as 
estimate of uhom. As  u*
bb is adopted as 
uncertainty contribution to account for potential inhomogeneity. In case of the IRMM-1027v, for the  235U and  239Pu isotope 

bb sets  the limits  of the study to detect inhomogeneity, the larger value  of  sbb or u*

15 

yNMSMSswithinbetweenrelbb,yνNMSuMSwithinwithin*relbb4,2yMSwithinν 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
amount  contents  the  sbb  and  for  the  238U  isotope  amount  content  u*
bb  could  be  used  to  assess  the  contribution  from  the 
homogeneity study. These values remained below 0.05% for all the three dominant isotopes thus; one can conclude that the 
batch is sufficiently homogeneous and fit for purpose. 

The  uncertainty  associated  with  homogeneity  was  assessed  via  the  accredited  software  SoftCRM®  [25]  and  the  ANOVA 
assumptions were tested using the open-source statistical software R [26].  

4.2 Homogeneity of the U and Pu isotope ratios 

The homogeneity assessment of the uranium and plutonium isotope amount ratios was deemed unnecessary. The IRMM-1027v 
LSD spikes were prepared by dissolution of the plutonium and uranium metals, dispensing of the solution into individual units 
and drying. Any differences in the isotope amount ratios could only stem from a contamination with plutonium and uranium of 
a different isotopic composition, from the isotope fractionation during the evaporation of the nitrate solution in the vial and 
from an incomplete mixing of the uranium metals. Dedicated glove boxes were used for the preparation of the spikes with no 
other sources of uranium and plutonium, so the contamination can be excluded. The drying temperature was less than 60 °C, 
where the fractionation effects are negligible. Moreover, the results of the process control measurements (see Section 3.3) for 
the uranium and plutonium isotope amount ratios agreed with the values from the gravimetric preparation, confirming the 
isotope mixing of the metals. For these reasons, no heterogeneity of the plutonium and uranium isotope amount ratios is to be 
expected in the vials of IRMM-1027v. This has been confirmed in the certification of previous batches of the IRMM-1027 LSD 
series.  

4.3 Minimum sample intake 

The minimum sample intake is the minimum amount of sample that is representative for the whole unit and thus should be 
used in an analysis. Using sample sizes equal to or above the minimum sample intake guarantee the certified value within its 
stated uncertainty. 

The whole amount of sample per unit has to be used and thus equals the minimum sample intake. Quantification of within-unit 
inhomogeneity to determine the minimum sample intake for IRMM-1027v is therefore not necessary.  

5.  Stability 

Stability testing is necessary to establish conditions for storage (long-term stability) as well as conditions for dispatch to the 
customers (short-term stability). The IRMM-1027v is a mixed U/Pu reference material, consisting of U and Pu radionuclides. It 
should be noted that the term 'stability' in this context does not refer to radioactive decay. Radionuclides are naturally decaying 
according to their half-lives, a process which is quantitatively predictable using the decay data [6, 7]. 

5.1 Short-term stability 

In the scope of the preparation and certification IRMM-1027t batch, a thorough short-term stability study of the CAB with 
dioctyl phthalate plasticizer (DOP) and with CMC was carried out [17]. 

The test samples contained CAB/DOP and CMC material without any plutonium and uranyl nitrates. They were stored at 4 °C 
and 60 °C for one week at each temperature. The reference temperature was set to 18 °C. Six units for each temperature were 
prepared (36 units in total). Only visual inspection of the selected units was made before and after the test to assess any 
detachment of the coating/foam. 

No flaking - in case of CAB with DOP – and/or fluid material – in case of CMC – could be observed before and after the test. 
The CAB with DOP coating did not change at all at any of the three temperature points. In case of the CMC foam, an ongoing 
reaction accelerated by the temperature (at 60°C) was observed. As the foam still contains unreacted HNO3 or nitrous gases – 
being the origin of the brownish colour of the fresh foams  – the foam has even further matured and discoloration can be 
noticed. However, this colour change of the foam does not affect the integrity or the stability of the material as demonstrated 
during the INS-CRM project [14]. 

Transport is often referred to as short-term stability. The transport does not affect the stability of the actinide matrix but it can 
have an influence on the cellulose based stabilizing matrices hence on the shelf-life and usability of the CRMs. For this reason, 
ten units of IRMM-1027v with each type of stabilizing matrices (CAB/DOP and CMC) were selected to undergo random vibration 
tests on a L0315M-PA103 Vibration Test System to simulate transport conditions. This electrodynamic shaker has a working 
frequency range of 5-4500 Hz. It is operated via the Spider MIMO Vibration Control System software.  

16 

 
Figure 5 Securing the test sample on the transport simulator (Source: EC JRC G.2) 

The test sample was placed on the vibration table as shown in Figure  5 and the random vibration module of the  ISTA 2A 
procedure [27] was set up and performed. The test ran for 180 minutes and an overall Grms level of 1.15 (root mean square 
acceleration, the square root of the area under the acceleration spectral density curve) was constructed. The details of the set 
acceleration  versus  frequency  profile  is  shown  in  Table  3  and  Figure  6.  The  environmental  conditions  at  the  time  of  the 
measurement and during the days before the test were the following: 20-22°C, 55-65% relative humidity and atmospheric 
pressure. The test was done on the same packaging that is used for the transport i.e. the packed units were placed into an 
EMMA container which was put into a Type A package (TNB 169) and a polystyrene shock absorber was placed between the 
layers. The Type A container remained in upright standing position throughout the run which is the intended shipping position. 

Table 3 The programmed acceleration versus frequency profile 

Frequency (Hz) 

PSD Level, g

2

/Hz 

1.0 
4.0 
100.0 
200.0 

0.0001 
0.01 
0.01 
0.001 

Figure 6 The programmed acceleration versus frequency profile (green line) and the control signal (blue line). Orange 
lines represent low and high alarm limits. Red lines represent low and high abort limits. 

17 

 
 
 
 
As it can be seen from Figure 6, the vibration simulator could correctly match the desired acceleration versus frequency profile 
except from slight anomalies in the low frequency region (1-5 Hz) where the signal moved close to the abort limits. These 
anomalies do not limit the usefulness of the obtained results because this frequency range usually affects very heavy objects 
(e.g. a building). Therefore we do not expect the low frequency region to have any influence on our test object (<7kg) nor on the 
packed CRMs that weighs a few grams only. 

The simulation was performed around 1-1.5 years after preparation of the CRMs to mimic real life situation (the units are 
usually shipped to the customers around 1 year after preparation).  

The main evaluation criterion was based on the appearance of the spikes before and after performing the transport simulation 
test. Figure 7 and Figure 8 show that there was no change in the appearance of the spikes, there are no flakes, cracks or loose 
particles observed after the study neither for the CMC nor for the CAB/DOP matrices. Therefore, we can conclude underpinned 
by the observed data  that the safe transport of 1-1.5 years old IRMM-1027v units can be guaranteed. Transport does not 
influence the usability and shelf-life of the CRM. 

Figure 7 IRMM-1027v CRM units embedded into CMC matrix before (top) and after (bottom) the transport simulation. 

18 

 
 
 
 
 
 
Figure  8  IRMM-1027v  CRM  units  embedded  into  CAB/DOP  matrix  before  (top)  and  after  (bottom)  the  transport 
simulation. (Please, note that the order of the units changed.) 

IRMM-1027v  LSD  spikes  are  packed  and  shipped  to  customers  following  the  legal  requirements  related  to  radioprotection 
measures  for  transport  of  radioactive  materials  [28].  IRMM-1027v  LSD  spikes  are  considered  stable  regarding  its  isotopic 
composition and the amount content during dispatch and can be shipped to customers under normal temperature conditions. 
No additional uncertainty component (usts, rel = 0) was applied.  

5.2 Long-term stability 

The change of the reference values with time of the U/Pu CRM IRMM-1027 batches can be perfectly described by radioactive 
decay equations and therefore have  to be compared to  the given reference date on the certificate.  These decay-corrected 
certified values are valid as long as the stabilizing organic matrix remains sufficiently intact that allows full sample intake 
without the risk of loss of the material when opening the vial. Therefore, no additional uncertainty component (ults, rel = 0) has 
to be applied to the certified values but the degradation process investigated in prior exploratory research of the stabilizing 
matrix limits the shelf-life of the IRMM-1027 series of LSD spikes to 5 years. 

The long-term stability of IRMM-1027 LSD spikes prepared with CAB has been demonstrated via the results of the stability 
monitoring of previous batches of LSD spikes for the period of three years [29] and the verification results of IRMM-1027m 
over a period of four years after the certification in the context of the inter-calibration of JRC-IRMM spike CRMs [30, 31, 32]. 
Furthermore, the JRC-Geel (Belgium), the JRC-Karlsruhe (Germany) and the IAEA at Seibersdorf (Austria) are engaged in mutual 
verification measurements of mixed uranium-plutonium spike reference materials via EC support task to the IAEA [33]. In the 
frame of this support task, verification measurements of randomly selected IRMM-1027 LSD spikes from different batches are 
performed up to two years after the issuance of the certificate. This is not only an external verification of the certified values 
but also a demonstration of the long-term stability of the IRMM-1027 series of LSD spikes. 

The long-term stability of the LSD spikes prepared with CMC and CAB/DOP can be demonstrated via the results of the INS-CRM 
exploratory research project [14,  15, 16]. In the study, the stability of the CMC foams is visually inspected at regular time 
intervals. Discoloration, cavity formation or collapsing of the CMC foam may occur with time. However, as long as the foam 
adheres to the vial; these effects do not influence the quality of the LSD spikes and therefore, the certified values can be 
guaranteed.  The  main  findings  of  the  shelf-life  of  the  IRMM-1027  series  of  LSD  spikes  was  summarized  in  the  previous 
certification report, IRMM-1027u [18]. A more detailed discussion of the topic will be published soon. 

6.  Characterisation 

The material characterisation is the process of determining the property values of a reference material.  

The material characterisation for the uranium and plutonium isotope amount ratios and for the mass of uranium and plutonium 
was based on gravimetric preparation of the mother solution, confirmed by independent analysis. The IRMM-1027v series of 
LSD spikes was prepared by dispensing an aliquot (about 2.5 g) of the mother solution into individual units by an automated 
system and subsequent drying. The masses of dispensed aliquots per unit before drying are given in  Annex 12. The mother 
solution was prepared by gravimetric mixing of uranium and plutonium metals (see Section 3.2).  

Each unit of IRMM-1027v LSD spike is certified for the mass of  239Pu,  235U and  238U and the n(234U)/n(238U), n(235U)/n(238U), 
n(236U)/n(238U), n(238Pu)/n(239Pu), n(240Pu)/n(239Pu), n(241Pu)/n(239Pu), and n(242Pu)/n(239Pu) amount ratios. 

6.1 Purity of the starting materials 

The purity of the starting U materials (metals) was taken from the corresponding certificates (Annex 2 Annex 4). The purity of 
the Pu MP2 metal was calculated for November 1, 2019 (Annex 14) from the original purity of the CETAMA certificate (Annex 
5). 

19 

 
 
6.2 Masses of 235U, 238U, 239Pu , U and Pu isotope amount ratios and their uncertainties 

The mass of 235U, 238U, 239Pu and the U and Pu isotope amount ratios in each individual unit of IRMM-1027v are calculated 
from the gravimetric preparation of the mother solution. The following parameters were taken into account: the mass of the 
metals, their purity and isotopic composition (e.g. isotope amount ratios), the mass of the mother solution and the mass of an 
aliquot dispensed into each vial. In Table 4, the data supporting the calculation of the masses of 235U, 238U, 239Pu and Pu and U 
amount ratios of IRMM-1027v are summarised. 

Table 4 Gravimetric mixing to prepare the mother solution of IRMM-1027v (Source: EC JRC G.2) 

Mass 1) [g] 

Purity 2) [g/g] 

Isotope amount ratios 3)  
[mol/mol] 

U amount content 4) 

[µmol/g] 

MP25 

EC NRM 1015 

NBL PO CRM 116-A5 

Mother 
solution5 

1.71006(07) 

40.46211(08) 

10.14037(06) 

2352.50(04) 

0.99824(40) 

0.99985(05) 

0.99945(14) 

n(238Pu)/n(239Pu) 
0.00002787(26) 

n(240Pu)/n(239Pu) 
0.0224103(51) 

n(241Pu)/n(239Pu) 
0.0001279(17) 

n(242Pu)/n(239Pu) 
0.00007573(78) 

2.7986(25) 

n(234U)/n(238U) 
0.00005548(22) 

n(233U)/n(235U) 
0.0000003863(86) 

n(235U)/n(238U) 
0.0072593(36) 

n(236U)/n(238U) 
0.000000151(40) 

n(234U)/n(235U) 
0.0115836(97) 

n(236U)/n(235U) 
0.0094713(77) 

n(238U)/n(235U) 
0.051277(41) 

Isotope amount fraction 4) 

[mol/mol] 

n(235U)/n(U)  
0.916107(22) 
1) The masses of the metals are obtained from the weighing certificate, see Annex 12.  
2) The decay-corrected purity of the Pu metal (see Annex 14) and the purity of the U metals. For the original metal certificates, see 
Annex 2 - Annex 6. 
3) The decay-corrected Pu isotope amount ratios and the U isotope amount ratios. For the original certificates see Annex 3 - Annex 6. 
4) The U isotope amount content and amount fraction are obtained from the metal certificates; see Annex 7. 
5) The numbers in parenthesis are the expanded uncertainties. The coverage factors were established  based on the t-distribution for 

the associated effective degrees of freedom. 

The uncertainties associated to the characterisation of the certified masses (uchar) of 235U, 238U and 239Pu in the individual units 
are composed of several contributions, which can be derived from the gravimetric mixture of the mother solution (Table 5). The 
contributors are the following: the uncertainties on the mass determinations (uchar,rel1 - metals, uchar,rel2 -  mother solution and 
uchar,rel3 – dispensed aliquot into the vial), the uncertainty on the purity of the metals (uchar,rel4), and the uncertainties on the 
isotope amount ratios (uchar,rel5 ). The detailed calculations of the mass fractions, amount fractions and the most important 
uncertainty budgets are given in Annex 13 and Annex 14. The uncertainty of the mass determination of the aliquot (dispensing) 
is the major contributor to the combined standard uncertainty associated to the characterisation for the U isotope amount 
contents. It is also an important contributor to the combined standard uncertainty of characterisation for 239Pu isotope amount 
content, the second largest after the purity of the MP2 metal. 

The uncertainties associated to the characterisation  of the certified U and Pu isotope amount ratios are  also composed of 
several contributions i.e. the uncertainty on the mass determination of the metals, the uncertainty on the purity of the metals, 
and the uncertainty on the isotope amount ratios. The detailed calculations of the uranium and plutonium isotope amount ratios 
and their uncertainty budgets are given in Annex 13 and Annex 14.  

20 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Table 5 Uncertainty budgets for the masses of  235U, 238U and 239Pu in the gravimetric mixture in the first unit #1 of 
IRMM-1027v as  an example. The main uncertainty contributions associated to  the characterisation are highlighted. 
(Source: EC JRC G.2) 

Relative standard uncertainty contribution 

uchar,rel1 

1) 

uchar,rel2

 2) 

uchar,rel3

 3) 

uchar,rel4 

4) 

uchar,rel5 

5) 

[%] 

[%] 

0.00029 

0.00085 

0.00010 

0.00085 

0.0020 

0.00085 

[%] 

0.012 

0.012 

0.012 

[%] 

0.0056 

0.0025 

0.020 

[%] 

0.0018 

0.000506) 

0.00025 

235U 

238U 

239Pu 

Combined relative 
uncertainty 

uchar,rel 7) 

[%] 

0.013 

0.012 

0.023 

    1) Relative standard uncertainty of the mass determination of the metals, see Annex 13 and Annex 14 denoted as mUCRM116A for 235U, mUEC101 
for 238U and mPuMP2 for 239Pu. The respective uncertainties of the mass determinations can be found in Annex 12. 
      2) Relative standard uncertainty of the mass determination of the mother solution, see Annex 13 and Annex 14 denoted as msolution1027v. 
The respective uncertainty of the mass determination can be found in Annex 12. 
      3) Relative standard uncertainty of the mass determination of the aliquot in the first vial, see Annex 13 and Annex 14 denoted as maliquot1. 
The respective uncertainties of the mass determination can be found in Annex 11. 
      4) Relative standard uncertainty of the purity of the metals, see Annex 13 and Annex 14 denoted as ηpurityEC101, ηpurityCRM116A and ηMP2Nov2019. 
The respective purities can be found in the metal certificates  Annex 2 - Annex 5. For the CETAMA MP2 metal, the purity is decayed in a 
separate GUM file to the 1 January 2007 and from that date (ηMP2Jan2007) is decayed further to the certification date 1 November 2019. 
      5) Relative standard uncertainty of the major isotope amount ratios, see Annex 13 and Annex 14 denoted as R238U/235Ub for NBL PO CRM-
116-A; and R240Pu/239Pu for CETAMA MP2. The respective isotope amount ratios can be found in Annex 3, Annex 5 - Annex 7. 
     6) For EC NRM 101 the relative standard uncertainty of the two most important isotope amount ratios  R235U/238Ua and R238U/235Ub were 
combined. 

      7)  The  final  combined  relative  uncertainty  is  calculated  using 𝑢char,rel = √∑ (𝑢𝑐ℎ𝑎𝑟,𝑟𝑒𝑙,𝑖
different uncertainty contributors.  

5
𝑖=1

2

)
,  assuming  no  correlation  between  the 

6.3 Weighing and associated uncertainties 

Masses of dispensed aliquots of the mother solution per unit used for the calculation of the certified values can be found in 
Annex 11. The dispensed masses were corrected for air buoyancy, taking into account the density of the air and the sample, 
the ambient humidity, temperature and pressure inside the glove box. No evaporation loss was assumed. Traceability of the 
values  to  the  SI  is  ensured  by  weighing  a  calibrated  reference  weight  before  and  after  dispensing  a  series  of  96  units.  A 
correction factor (Knucomat) was applied based on the ratio of the last calibration of the reference weight and the mean value 
obtained during dispensing according to the following equation: 

𝑲𝒏𝒖𝒄𝒐𝒎𝒂𝒕 =  

𝒎𝒓𝒆𝒇,𝒄𝒂𝒍
𝒎𝒓𝒆𝒇,𝒓𝒆𝒂𝒅𝒐𝒖𝒕

Equation 4 

where  mref, readout is the mean value of the reference mass recorded at ambient conditions during dispensing and mref, cal is the 
mass value of the latest calibration of the same reference object after ambient condition correction. 
The uncertainty estimate on the dispensed mass (± 0.0006 g, coverage factor k = 2) is composed of several contributions, i.e. 
the uncertainty on the mass determination by an automated system, the uncertainty on the buoyancy correction, the uncertainty 
of the correction factor, and the uncertainty associated with the stability of the balance [20]. 

For the determination of the mass of the starting materials (metals) and the mother solution, substitution weighing was used. 
In the substitution weighing, the mass of a sample is determined through a series of mass determinations of the unknown (U) 
and a reference weight (S). The so called "SUUS" method was applied [19]. The uncertainty contributions in substitution weighing 
of the metals are the uncertainties associated with the calibrated reference weights (certificate), air buoyancy correction and 
the stability of the balance used in "SUUS" method. 

6.4 Isotope ratio confirmation measurements 

Four  unspiked  aliquots  (about  0.5  g  each)  of  the  IRMM-1027v  mother  solution  were  analysed  to  verify  the  uranium  and 
plutonium isotope amount ratios by TIMS and alpha spectrometry. The U-Pu separation of the samples was performed using 
anion-exchange columns (Bio-Rad AG1-X4, 100-200 mesh, Bio-Rad, Hercules, USA) as described in detail in [21]. Apart from 
that, external verification data performed by at IAEA-SGAS and JRC-KA on randomly selected CAB/DOP or CMC coated IRMM-
1027v units are also presented. 

21 

 
  
 
The results of the uranium and plutonium isotope amount ratio confirmation measurements in the mother solution of IRMM-
1027v  were  compatible  with  the  values  from  the  gravimetric  preparation,  except  for  two  of  the  four  aliquots  for  the 
n(236U)/n(238U) amount ratio. Even in these cases, the compatibility check (see equation 5) results were below 3 and the ratio 
was verified by external verification on individual units by IAEA-SGAS and JRC-KA. Therefore, this isotope ratio was included in 
the certificate. As it is apparent from Figure 9 all U isotope ratios show a slight positive bias of the observed values to the 
gravimetrical value even though they are all within uncertainty with the exception of one measurement of the n(236U)/n(238U) 
amount ratio. The relative differences are 0.02% for  n(235U)/n(238U), 0.04% for  n(234U)/n(238U) and 0.08% for n(236U)/n(238U) 
amount ratios based on the verification data of all three institutes.  

Figure 9 Uranium isotope ratio verification measurements for a) n(235U)/n(238U) b) n(234U)/n(238U) and c) n(236U)/n(238U). Symbol 
codes: triangle – JRC-GE, circle – IAEA-SGAS, square – JRC-KA. Colour codes: orange – aliquot, red – CAB/DOP, blue – CMC. Error 
bars show the expanded uncertainties (For JRC-GE results coverage factors are based on the t-distribution for the associated 
effective degrees of freedom that corresponds to a level of confidence of about 95 %). (Source: EC JRC G.2, IAEA-SGAS, EC JRC 
G.II.6.) 

Due to an isobaric interference with 238U coming from the incomplete removal of uranium in the plutonium fraction TIMS would 
provide a deviating value for the n(238Pu)/n(239Pu) ratio. For this reason, alpha spectroscopy was used as alternative method for 
the verification of the gravimetrical n(238Pu)/n(239Pu) ratio. Due to the corona pandemic, we could only analyse a single aliquot 
(with  two  replicates).  The  result  of  this  measurement  and  the  external  verification  by  IAEA-SGAS  and  JRC-KA  verified  the 
gravimetrical ratio. Therefore, this isotope ratio was certified, as well. The other Pu isotope ratios were measured by TIMS. These 
verification  measurements  are  summarized  in  Figure  10.  The  relative  difference  to  the  gravimetrical  value  on  the 
n(240Pu)/n(239Pu) isotope ratio is -0.01%, the relative differences on the other ratios vary but all of the expanded uncertainties 
of the individual measurements overlap with that of the gravimetrical (certified) value. All results pass the compatibility check.  

Furthermore,  the  compatibility  check  was  performed  for  the  results  of  the  confirmation  measurements  (IDMS)  using  the 
compatibility equation (equation 5) [34]. We set the following criteria for the compatibility check: compatibility values that are 
less than 2 pass, values between 2 and 3 pass with a warning and values larger than 3 fail to pass the check. We  have not 
observed any values larger than 3 during the verification exercise and only few between 2 and 3, which are highlighted in the 
respective tables.  

22 

-0.10-0.050.000.050.100.1512347968023173510361aliquot/unitRelative difference (%)n(235U)/n(238U) ratioa)-0.50-0.250.000.250.5012347968023173510361aliquot/unitRel. diff. (%)n(234U)/n(238U) ratiob)-0.50-0.250.000.250.5012347968023173510361aliquot/unitRel. diff. (%)n(236U)/n(238U) ratioc) 
 
 
𝒄𝒐𝒎𝒑𝒂𝒕𝒊𝒃𝒊𝒍𝒊𝒕𝒚 =  

𝑿𝑰𝑫𝑴𝑺−𝑿𝒄𝒆𝒓𝒕

𝟐
√𝒖𝑰𝑫𝑴𝑺

𝟐
+𝒖𝒄𝒆𝒓𝒕

Equation 5 

XIDMS 

Xcert 

uIDMS  

ucert 

individual result obtained by IDMS  

gravimetric value established by characterisation 

standard uncertainty obtained by IDMS 

standard uncertainty of the certified value 

The outcome of the compatibility check is summarized in Table 6. 

Figure  10  Plutonium  isotope  ratio  verification  measurements  for  a)  n(240Pu)/n(239Pu)  (TIMS)  b)  n(238Pu)/n(239Pu)  (alpha-
spectrometry) and c) n(241Pu)/n(239Pu) (TIMS) and d) n(242Pu)/n(239Pu) (TIMS) ratios. Symbol codes: triangle – JRC-GE, circle – 
IAEA-SGAS,  square  –  JRC-KA.  Colour  codes:  orange  –  aliquot,  red  –  CAB/DOP,  blue  –  CMC.  Error  bars  show  the  expanded 
uncertainties  (For  JRC-GE  results  coverage  factors  are  based  on  the  t-distribution  for  the  associated  effective  degrees  of 
freedom that corresponds to a level of confidence of about 95 %). (Source: EC JRC G.2, IAEA-SGAS, EC JRC G.II.6.) 

Table 6 Results of the compatibility evaluation for the isotope ratios (Source: EC JRC G.2, IAEA-SGAS, EC JRC G.II.6) 

Aliquot or vial No. 

1027v-aliquot 1 

1027v- aliquot 2 

1027v- aliquot 3 

1027v- aliquot 4 

n(235U)/ 
n(238U) 
ratio 

1.05 

0.93 

0.47 

1.62 

n(234U)/ 
n(238U) 
ratio 

n(236U)/ 
n(238U) 
ratio 

n(240Pu)/ 
n(239Pu) 
ratio 

n(238Pu)/ 
n(239Pu) 
ratio 

n(241Pu)/ 
n(239Pu) ratio 

n(242Pu)/ 
n(239Pu) 
ratio 

1.17 

0.65 

0.20 

0.75 

1.50 

2.32 

1.04 

2.96 

0.68 

0.56 

0.55 

0.89 

N/A 

1.10 

N/A 

N/A 

0.85 

0.25 

0.66 

0.70 

0.06 

0.68 

1.26 

1.17 

23 

-0.10-0.08-0.06-0.04-0.020.000.020.040.060.080.1012347968023173510361aliquot/unitRelative difference (%)n(240Pu)/n(239Pu) ratioa)-10-5051027968023173510361aliquot/unitRel. diff. (%)n(238Pu)/n(239Pu) ratiob)-5051012347968023173510361aliquot/unitRel. diff. (%)n(241Pu)/n(239Pu) ratioc)-5051012347968023173510361aliquot/unitRel. diff. (%)n(242Pu)/n(239Pu) ratiod) 
 
 
 
1027v-79 

1027v-680 

1027v-231 

1027v-735 

1027v-10 

1027v-361 

1.98 

0.61 

1.63 

1.95 

0.09 

0.30 

1.44 

0.52 

1.15 

1.13 

0.01 

0.03 

1.22 

0.50 

1.17 

0.95 

0.14 

0.04 

0.24 

0.28 

0.48 

0.35 

0.05 

0.41 

0.10 

0.10 

0.25 

0.25 

0.30 

0.08 

0.33 

0.45 

0.35 

0.04 

0.68 

0.27 

0.07 

0.12 

0.10 

0.06 

0.36 

0.08 

The relative standard uncertainty contribution of the uranium and plutonium isotope amount ratios from the characterisation 
assessment (gravimetric preparation) are summarised in Table 7. As no uncertainty contribution associated with homogeneity 
is assigned to these ratios (see Section 4.2), uchar represents the combined standard uncertainty. 

Table  7  The  U  and  Pu  isotope  amount  ratios  and  their  relative  standard  uncertainties  from  the  characterisation 
assessment of IRMM-1027v (Source: EC JRC G.2) 

Value 1) 

[mol/mol] 

0.0027807 

0.242509 

0.0022322 

uchar  

[mol/mol] 

0.0000011 

0.000016 

0.0000009 

0.00002787 

0.00000013 

0.0224103 

0.0001279 

0.0000025 

0.0000008 

n(234U)/n(238U) 

n(235U)/n(238U) 

n(236U)/n(238U) 

n(238Pu)/n(239Pu) 

n(240Pu)/n(239Pu) 

n(241Pu)/n(239Pu) 

n(242Pu)/n(239Pu) 

0.00007573 
The reference date for the isotope amount ratios is November 1, 2019. 

0.00000039 

1) 

uchar, rel 

[%] 

0.040 

0.0066 

0.041 

0.47 

0.011 

0.66 

0.52 

The confirmation measurement for the U and Pu isotope amount ratios in the selected vials of IRMM-1027v were deemed 
unnecessary. The results of the process control measurements (Annex 9) on the mother solution confirmed the complete mixing 
of the uranium and plutonium metals, and therefore, enabled the characterisation of the uranium and plutonium isotope amount 
ratios in IRMM-1027v based on the gravimetric preparation. It was already demonstrated in previous batches of IRMM-1027 
spikes that there was no significant difference observed between the measured isotope ratios in the mother solution and in the 
dried spikes [12, 17, 35]. Moreover, all the external verification units analysed by IAEA-SGAS and JRC-KA confirmed all the 
gravimetrical U and Pu isotope amount ratios.  

6.5 Amount content confirmation measurements 

The confirmation measurements and the homogeneity study were performed on the same set of units (see Section 6) although 
only the results obtained on single spiked units were used for the uncertainty calculation associated with the homogeneity of 
the sample. All randomly selected units were used for verification unless they were excluded for technical reason.   

Twelve units of IRMM-1027v were randomly selected from the whole batch and analysed by ID-TIMS to verify the uranium and 
plutonium amount contents from gravimetric preparation. To 12 of these units, about 2.0 g of mixed 233U/242Pu spike (IRMM-
046c) in 5 M HNO3 was weighed in and evaporated to dryness. Subsequently, the isotopic equilibrium, chemical separation and 
isotopic measurements on Triton TIMS were carried out as described in [21]. The weighing certificates and ID-TIMS reports 
regarding to the single unit verification of the IRMM-1027v batch can be found in Annex 15 and Annex 16. 

Independently  prepared  and  certified  uranium  (CRM-116A)  and  plutonium  quality  control  (QC)  (NBL  126)  materials  were 
measured together with each set of sample turrets as QC samples. A correction factor based on the relative biases of the QC 
measurements was applied to all verification results that were spiked with the same ampoule of IRMM-046c as the respective 
QC sample. The latter was important because statistically significant ampoule-to-ampoule differences were observed for some 
of the spike ampoules. The bias correction factor was applied according to Equation 5. 

24 

 
 
 
 
 
 
𝒄𝑰𝑫𝑴𝑺,𝒄𝒐𝒓𝒓 = 𝒄𝑰𝑫𝑴𝑺,𝒖𝒏𝒄𝒐𝒓𝒓 ∗

𝟏
 𝟏+𝑸𝑪𝒃𝒊𝒂𝒔

cIDMS, corr 

corrected amount content value of the selected isotope 

cIDMS, uncorr 

uncorrected amount content value of the selected isotope 

Equation 6 

QCbias 

IDMS QC bias relative to the gravimetrical QC value (expressed as decimal) 

In case it was necessary (compatibility value calculated by Equation 5 was larger than 2), an additional uncertainty contribution 
was assigned to the IDMS values depending on the results of the consistency check. The consistency check was applied under 
repeatability conditions i.e. on sample subsets that were measured on the same TIMS turret as described by Kessel et al. [36].       

At  JRC-GE,  the  IDMS  confirmation  measurements  obtained  with  the  mixed  233U/242Pu  spike  (IRMM-046c)  were  used  for 
verification. One unit was excluded due to technical issue (weighing) therefore 11 results are reported for all isotopes. IAEA-
SGAS reported 10 results each on U and Pu assay, respectively and JRC-KA reported 4 data each as total U and Pu mass per 
unit, respectively. The results of the confirmation measurements and the randomly selected unit numbers are shown in Figure 
11- Figure 13. 

Figure 11 The amount content of 235U in the selected vials of IRMM-1027v measured by ID-TIMS at JRC-GE expressed 
as the relative difference to the gravimetric value. Colour codes: red – CAB/DOP, blue – CMC. Error bars show the relative 
expanded  uncertainties  (coverage  factors  are  based  on  the  t-distribution  for  the  associated  effective  degrees  of 
freedom  that  corresponds  to  a  level  of  confidence  of  about  95  %).  Red  dotted  lines  show  the  combined  relative 
expanded  uncertainty  %)  assigned  to  the  gravimetric  value  (coverage  factor  k  =  2  that  corresponds  to  a  level  of 
confidence of about 95 (Source: EC JRC G.2.) 

25 

-0.3-0.10.10.326231343176664137618176507749887unitRelative difference (%) 
 
 
Figure 12 The amount content of 238U, U assay or U mass content for the selected units of IRMM-1027v measured by 
ID-TIMS. Symbol codes: triangle – JRC-GE (238U amount content), circle – IAEA-SGAS (U assay), square – JRC-KA (U mass 
per unit). Colour codes: red – CAB/DOP, blue – CMC. Error bars show the relative expanded uncertainties (For JRC-GE 
results  coverage  factors  are  based  on  the  t-distribution  for  the  associated  effective  degrees  of  freedom  that 
corresponds to a level of confidence of about 95 %). Red dotted lines show the combined relative expanded uncertainty 
assigned to the gravimetric value (coverage factor k = 2 that corresponds to a level of confidence of about 95 %) 
(Source: EC JRC G.2, IAEA-SGAS, EC JRC G.II.6.) 

Figure 13 The amount content of 239Pu, Pu assay or Pu mass content in the selected units of IRMM-1027v measured 
by ID-TIMS expressed as the relative difference from the gravimetric value. Symbol codes: triangle – JRC-GE (239Pu 
amount content), circle – IAEA-SGAS (Pu assay), square – JRC-KA (Pu mass per unit). Colour codes: red – CAB/DOP, blue 
– CMC. Error bars show the relative expanded uncertainties (For JRC-GE results coverage factors are based on the t-
distribution for the associated effective degrees of freedom that corresponds to a level of confidence of about 95 %). 
Red dotted lines show the combined relative expanded uncertainty assigned to the gravimetric value (coverage factor 
k = 2 that corresponds to a level of confidence of about 95 %) (Source: EC JRC G.2, IAEA-SGAS, EC JRC G.II.6.) 

The results of the confirmation measurements for the 235U, 238U and 239Pu amount content, U and Pu assay and U and Pu mass 
per unit agreed within measurement uncertainties with the values from the gravimetrical preparation of IRMM-1027v. 

The results of the compatibility evaluations are summarised in Table 8-Table 10.  

26 

-0.20.00.22623134317666413761817650774988719231545782789444444562702855273385496620unitRelative difference (%)-0.20.00.22623134317666413761817650774988719231545782789444444562702855273385496620unitRelative difference (%) 
 
 
Table 8 Results of the compatibility evaluation for the 235U, 238U and 239Pu amount content (Source: EC JRC G.2) 

Vial No. 

1027v-262 

1027v-313 

1027v-431 

1027v-766 

1027v-64 

1027v-137 

1027v-618 

1027v-176 

1027v-507 

1027v-749 

1027v-887 

235U amount 
content 

238U amount content 

239Pu amount 
content 

0.86 

-0.06 

2.27 

1.86 

0.95 

0.55 

0.23 

0.35 

1.60 

1.02 

2.68 

0.23 

-0.20 

1.38 

0.66 

0.38 

-0.08 

0.21 

-0.16 

0.74 

-0.26 

1.71 

0.16 

1.34 

-0.09 

0.08 

-1.02 

-1.40 

-0.20 

-1.11 

-0.25 

-0.62 

-0.44 

Table 9 Results of the compatibility evaluation for the U and Pu assay (Source: IAEA-SGAS) 

U assay 

Pu assay 

1027v-192 

1027v-315 

1027v-457 

1027v-827 

1027v-894 

1027v-044 

1027v-444 

1027v-562 

1027v-702 

1027v-855 

-1.86 

-1.21 

-0.72 

0.66 

-1.54 

-1.13 

-1.37 

-1.86 

0.01 

-0.07 

-1.90 

-2.08 

-0.74 

-0.91 

-0.24 

-1.90 

-1.35 

-0.74 

-0.74 

-1.53 

Table 10 Results of the compatibility evaluation for the U and Pu mass per unit (Source: EC JRC G.II.6) 

U mass/unit 

Pu mass/unit 

1027v-273 

1027v-385 

1027v-496 

1027v-620 

-0.16 

-0.11 

-0.11 

-0.09 

-0.11 

0.00 

-0.05 

0.11 

From Table 8 it can be seen that the compatibility is between -2 and +2 at a 95 % CI for all the 235U, 238U and 239Pu amount 
contents, with the exception of two verification units for 235U. Nevertheless, it can be concluded that the values of the gravimetric 

27 

 
 
 
 
 
 
preparation are sufficiently verified by results obtained via IDMS and the material is fit for purpose. As for the previous batches, 
there was no significant difference between the vials treated with CAB/DOP and CMC. 

Even after correcting for QC bias, all IDMS results of 235U, 238U and 239Pu amount contents show a slight bias compared to the 
gravimetric values (+0.05%, +0.03% and -0.02%, respectively (Figure 11 - Figure 13)). A thorough investigation was made 
concerning the measurements and calculations but we could not find an explanation for the deviations. All results of the ID-
TIMS measurements confirmed the gravimetrical values within expanded uncertainties. Therefore, this bias does not affect the 
certified values and their assigned uncertainties.  

The quantity values and uncertainties associated with CRM characterisation and the internal verification data were computed 
via the commercially available software, GUM Workbench [37]. 

7.  Value Assignment 

Certified values are values that fulfil the highest standards of accuracy. Certified values for IRMM-1027v were assigned on the 
basis of the gravimetric preparation as a primary method of measurement. Full uncertainty budgets in accordance with the ISO 
GUM 'Guide to the Expression of Uncertainty in Measurement' [4] were established.  

7.1 Certified values and their uncertainties 

The assigned uncertainty consists of uncertainties related to characterisation,  uchar (Section 6), between-unit inhomogeneity, 
uhom (Section 3) and potential degradation during transport (usts) and long-term storage, ults (Section 5). As described in Section 
5 the uncertainty related to degradation during transport and long-term storage was found to be negligible. These different 
contributions were combined to estimate the expanded uncertainty of the certified value (UCRM) with a coverage factor k as:  

𝑼𝑪𝑹𝑴 = 𝒌 ∙   √𝒖𝒄𝒉𝒂𝒓

𝟐 + 𝒖𝒉𝒐𝒎

𝟐

Equation 7 

- 

- 

uchar was estimated as described in Section 6 

uhom was estimated as described in Section 3. 

Because of sufficient degrees of freedom of the different uncertainty contributions, a coverage factor k of 2 was applied to 
obtain the expanded uncertainties. The certified masses and their uncertainties for unit No. 1 are summarised in Table 11. Its 
relative standard and expanded uncertainties are representative for all the units of the entire IRMM-1027v batch. The certified 
values of all 905 units are given in Annex 1. 

Table 11 Exemplary representation of certified masses and their uncertainties in unit #1 of IRMM-1027v as an example 
(Source: EC JRC G.2) 

Mass 

235U mass 

238U mass 

239Pu mass 

Certified value 
[mg] 

10.3301 

43.142 

1.7711 

uchar, rel 
[%] 

0.013 

0.012 

0.023 

uhom, rel 
[%] 

0.021 

0.024 

0.020 

1) 

UCRM, rel 
[%] 

0.049 

0.054 

0.062 

UCRM 1) 
[mg] 

0.0052 

0.023 

0.0011 

1) Expanded uncertainty, coverage factor k=2  

8.  Metrological traceability and commutability 

8.1 Metrological traceability  

Identity  

The measurands are structurally defined and independent of the measurement method. 

Quantity value 

The certified values are traceable to the values of the respective metal certificates (EC NRM 101, CETAMA MP2 and NBL PO 
CRM 116-A) and consequently either partly to the SI or the national metrology data base for the United States.  The values 
associated to the weighing are traceable to the SI via regular calibrations of the JRC G2’s principal mass standards. The mass 

28 

 
  
 
 
standards used for the calibration of balances and mass determination of the metals and the mother solution are in accordance 
with the maximum permissible error of class E1, E2 or F1 according to OIML-R 111:2004. More detailed information about the 
weight sets is available upon request. 

8.2 Commutability 

Many measurement procedures include one or more steps, which are selecting specific analytes (or specific groups of analytes) 
from  the  sample  for  the  subsequent  steps  of  the  whole  measurement  process.  Often  the  complete  identity  of  these 
'intermediate  analytes'  is  not  fully  known  or  taken  into  account.  Therefore,  it  is  difficult  to  mimic  all  analytically  relevant 
properties of real samples within a CRM. The degree of equivalence in the analytical behaviour of real samples and a CRM with 
respect  to  various  measurement  procedures  (methods)  is  summarised  in  a  concept  called  'commutability  of  a  reference 
material'. There are various definitions expressing this concept. For instance, the CLSI Guideline C-53A [38] recommends the 
use of the following definition for the term commutability: 

"The equivalence of the mathematical relationships among the results of different measurement procedures for an RM 
and for representative samples of the type intended to be measured." 

The commutability of a CRM defines its fitness for use and, thus, is a crucial characteristic in case of the application of different 
measurement methods. When commutability of a CRM is not established in such cases, the results from routinely used methods 
cannot be legitimately compared with the certified value to determine whether a bias does not exist in calibration, nor can the 
CRM be used as a calibrant. 

The IRMM-1027v is a dried nitrate in CAB/DOP or CMC certified for uranium and plutonium isotope amount ratios and masses 
of 235U, 238U and 239Pu per unit. This CRM is tailor-made by the JRC for its intended use and serves as a spike for determination 
of uranium and plutonium content by IDMS measurements of samples from input solutions at reprocessing plants and is not 
intended to be used for other measurement methods.  

9.  Instructions for use 

9.1 Safety information 

The IRMM-1027v series contains radioactive material. The ampoules should be handled with great care and by experienced 
personnel in a laboratory suitably equipped for the safe handling of radioactive materials. 

9.2 Storage conditions 

The material should be stored at room temperature in an upright position.  

The European Commission cannot be held responsible for changes that happen during storage of the material at the customer's 
premises, especially of opened samples. 

9.3 Instructions for use 

The spike has to be dissolved in the appropriate amount of acid (e.g. nitric acid with an amount of substance concentration of 
about c = 5 mol/ L) or sample solution to ensure the isotopic equilibrium between the spike and the sample. Heating on a 
hotplate (avoid boiling) may be applied to assist the dissolution process.  

9.4 Minimum sample intake 

The whole amount of sample per unit has to be used.  

9.5 Use of the certified value 

This spike CRM is for use as a spike isotopic reference material to measure the plutonium and uranium amount content in an 
unknown  sample  of  dissolved  nuclear  fuel  solution  using  IDMS.  The  amount  content  (Cx)  of  plutonium  or  uranium  can  be 
calculated using the following IDMS equation 8: 

 , 

Equation 8 

29 

yixixbbyxyRRRRRRmm)()(yxC  C 
 
 
where Cy is the element amount content of the spike, mx and my are the masses of sample and spike, respectively, Rx, Ry and 

Rb are the isotope amount ratios of the sample, the spike and the blend, respectively, 

 and 

 are the sums of 

all isotope amount ratios in sample and in spike, respectively.  

10. Conclusions 

A new batch of IRMM-1027 series of LSD spike CRMs was prepared and certified in compliance with international guidelines: 
IRMM-1027v. The material is certified for the U and Pu isotope amount ratios and for the mass of 235U, 238U and 239Pu per unit. 
This tailor-made CRM is applied for the determination of the U and Pu amount content of dissolved spent nuclear fuel by nuclear 
safeguards authorities and industry worldwide. Two cellulose-based materials, CAB/DOP and CMC were used as stabilisers to 
fix the dried nitrates at the bottom of the vials. Certified values for the masses of 235U, 238U and 239Pu and for the U and Pu 
isotope amount ratios were established by gravimetric preparation and confirmed by TIMS, ID-TIMS and alpha spectrometry as 
independent methods of measurement. The uncertainties of the certified values were established in compliance with the Guide 
to the Expression of Uncertainty in Measurement (GUM). The IRMM-1027v batch is fit for purpose and enables laboratories to 
meet the International Target Values for Measurement Uncertainties in Safeguarding Nuclear Materials (ITVs) ITV2010. A unit 
of IRMM-1027v contains about 54 mg of uranium with a relative mass fraction m(235U)/m(U) of 19.2 % and 1.8 mg of plutonium 
with a relative mass fraction m(239Pu)/m(Pu) of 97.8 % as dried nitrates in CAB/DOP or CMC matrices. 

30 

xiR)(yiR)( 
References

1  

2  

3  

4  

R. Jakopič, K. Toth, J. Bauwens, R. Buják, C. Hennessy, F. Kehoe, U. Jacobsson, S. Richter, Y. Aregbe, 30 years of IRMM-1027 
reference materials for fissile material accountancy and control: Development, production and characterisation, submitted 
to ESARDA Bulletin The International Journal of Nuclear Safeguards and Non-Proliferation 

ISO 17034, General requirements for the competence of reference materials producers, International Organization for 
Standardization, Geneva, Switzerland, 2016 

ISO  Guide  35,  Reference  materials  –  Guidance  for  characterisation  and  assessment  of  homogeneity  and  stability, 
International Organization for Standardization, Geneva, Switzerland, 2017 

ISO/IEC Guide 98-3:2008, Guide to the Expression of Uncertainty in Measurement (GUM, 1995), International Organization 
for Standardization, Geneva, Switzerland, 2008 

5   Wang, M. et al., The AME 2016 atomic mass evaluation (II). Tables, Graphs and References, Chinese Physics C, Vol. 41, No. 

6  

7  

8  

9  

3, 1603-2014, 2017 

http://www.nucleide.org/DDEP_WG/DDEPdata.htm 

R. Wellum, A. Verbruggen, R. Kessel, A new evaluation of the half-life of 241Pu, J. Anal. At. Spectrom., 24, 801-807, 2009 

International  Target  Values  2010  for  Measurement  Uncertainties  in  Safeguarding  Nuclear  Materials,  IAEA-STR-368, 
Vienna, November 2010 

L. Duinslaeger, K. Casteleyn, C.-I. Andor, R. Buda, R. C. Marquez, L. Commin, F. D. Amati, L. Embico, T. Enright, M. Hild, J. H. 
Domenech, A. Le Terrier, K. Luetzenkirchen, S. Mialle, S. Morel, A. Muehleisen, A. Nicholl, C. Nourry, D. Poublan, M. Ramos 
Pascual, G. Rasmussen, A. M. Sanchez-Hernandez, F. Sarli, S. Street, G. Suurkuusk, G. Toma, O. S. Valu, P. van Belle, D. 
Wojnowski,  E.  Zuleger,  F.  Lipcsei,  P.  Schwalbach,  S.  Synetos,  Euratom  On-Site  Laboratories  Refurbishments  and 
developments, ESARDA Bulletin, No. 56, June 2018 

10   K.  Casteleyn,  L.  Duinslaeger,  M.  Boella,  P.  Chare,  F.  Lipcsei,  P.  Schwalbach,  S.  Synetos,  T.  Enright,  A.  Le  Terrier,  K. 
Luetzenkirchen, P. Van Belle, E. Zuleger, Y. Aregbe, On-site Laboratories of Euratom: Ten Years of Excellent Results and 
Time to Renew, 52nd Annual Meeting of the Institute of Nuclear Materials Management (INMM), Palm Springs, USA, 2011 

11   A Alonso, R. Eykens, F. Kehoe, H. Kuhn, N. Surugaya, A. Verbruggen, R Wellum, Preparation and certification of New Type 

of Large Size Dried Spikes: Batch IRMM-1027f, GE/R/IM/36/02, 2002 

12   R. Jakopič, J. Bauwens, R. Bujak, C. Hennessy, F. Kehoe, U. Jacobsson, S. Richter, Y. Aregbe, Preparation and certification of 

Large-Sized Dried (LSD) spike IRMM-1027s, EUR 29274 EN, 2018 

13   R. Buják, L. Delva, M. Erkoc, J. Bauwens, R. Jakopic, L. Vincze, Y. Aregbe, L. Cardon, Long-term stability of cellulose acetate 
butyrate thin films for nuclear certified reference materials, Journal of Radionalaytical and Nuclear Chemistry 311, 877-
886, 2017 

14   Y. Aregbe, N. L. Banik, J. Bauwens, R. Buda, R. Buják, R. Carlos Marquez, K. Casteleyn, L. Duinslaeger, F. Kehoe, C. Hennessy, 
R. Jakopič, A. M. Sánchez Hernández, K. Tóth, E. Zuleger, INS-CRM: Innovative nuclear certified reference materials (CRM) 
for EURATOM safeguards and industry – Scientific Report – JRC114518, 2018 

15   A. M. Sanchez, K. Toth, Y. Aregbe, N. L. Banik, J. Bauwens, R. Buda, R. Bujak, R. Carlos Marquez, K. Casteleyn, L. Duislaeger, 
C. Hennessy, R. Jakopic, F. Kehoe, P. van Belle, E. Zuleger, Alternative nuclear certified reference materials for safeguards 
ad industry, 39th ESARDA Annual Meeting: Symposium, proceeding paper, Dusseldorf, Germany, 2017 

16   K. Toth, R. Buják, A. M. Sánchez Hernández, J. Bauwens, R. Carlos Marquez, R. Buda, N. L. Banik, R. Jakopič, E. Zuleger, Y. 
Aregbe, Research on long-term stability of mixed U and Pu large-sized dried (LSD) spikes for fissile material control, 
Progress in Nuclear Science and Technology, 5, 48-51, 2018 

17   R.  Jakopič,  J.  Bauwens,  R.  Buják,  C,  Hennessy,  F.  Kehoe,  U.  Jacobsson,  K.  Toth,  S.  Richter,  Y.  Aregbe,  Preparation  and 

certification of Large-Sized Dried (LSD) spike IRMM-1027t, EUR 29742 EN, 2019 

18   R. Bujak, K. Toth, J. Bauwens, C. Hennessy, F. Kehoe, U. Jakobsson, S. Richter, Y. Aregbe, Preparation and Certification of 

Large-Size Dried (LSD) Spike: IRMM-1027u, EUR 30759 EN, 2020 

19   OIML R111-1:2004 International Organization of Legal Metrology - Weights of classes E1, E2, F1, F2, M1, M1-2, M2, M2-

3 and M3, Part 1: Metrological and technical requirements, 2004. 

31 

 
 
 
20   A. Verbruggen, J. Bauwens, N. van De Steene, U. Jacobsson, R. Eykens, R. Wellum, Y. Aregbe, An automated system for the 

preparation of Large Size Dried (LSD) spikes, ATALANTE, Montpellier, France 2008 

21   R. Jakopič, J. Bauwens, R. Bujak, R. Eykens, C, Hennessy, F. Kehoe, H. Kühn, S. Richter, Y. Aregbe, Preparation and certification 

of Large-Sized Dried (LSD) spike IRMM-1027o, EUR 25857 EN, 2013 

22   M. J. T. Milton and T. J. Quinn, Primary methods for the measurement of amount of substance, Metrologia, 38, 289, 2001. 

23   C. Venchiarutti, R. Jakopic, C. Hennessy, K. Toth, Preparation and characterisation of uranium and plutonium quality control 
samples for isotope dilution mass spectrometry measurements and uncertainty estimation, J. Radioanal. Nucl. Chem., 
327, 1305-1316, 2021. 

24   T.P.J.  Linsinger,  J.  Pauwels,  A.M.H.  van  der  Veen,  H.  Schimmel,  A.  Lamberty,  Homogeneity  and  stability  of  reference 

materials, Accred. Qual. Assur., 6, 20-25, 2001 

25   G. Bonas, M. Zervou, T. Papaeoannou and M. Lees, ''SoftCRM'':A new Software for the Certification of Reference Materials, 

Accred. Qual. Assur., 8,101-107, 2003 

26   R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, 

Austria, 2014. 

27  

ISTA 2 Series Partial Simulation Performance Procedure, Packed Products 150 lb (68 kg) or Less, 2011. 

28  

IAEA Regulations for the Safe Transport of Radioactive Material, 1996 Edition, “Requirements”, IAEA Safety Standards 
Series No. TS-R-1 (ST-1, Revised), IAEA, Vienna, 2000 

29   R. Jakopič, J. Bauwens, R. Bujak, C. Hennessy, F. Kehoe, U. Jacobsson, S. Richter, Y. Aregbe, Preparation and certification of 

Large-Sized Dried (LSD) spike IRMM-1027r, EUR 28081 EN, 2016 

30   A.  Verbruggen,  J.  Bauwens,  R.  Eykens,  U.  Jacobsson,  R.  Jakopič,  F.  Kehoe,  H.  Kühn,  Y.  Kushigeta,  S.  Richter,  Y.  Aregbe, 

Preparation and certification of IRMM-1027m, Large-sized Dried (LSD) spike, EUR 24119 EN, 2009 

31   R. Jakopič, J. Bauwens, S. Richter, M. Sturm, A. Verbruggen, R. Wellum, R. Eykens, F. Kehoe, H. Kühn, Y. Aregbe, Preparation 

and development of new Pu spike isotopic reference materials at IRMM, ESARDA Bulletin, No. 46, 2011 

32   R. Jakopič, A. Verbruggen, R. Eykens, F. Kehoe, H. Kühn, Y. Kushigeta, U. Jacobsson, J. Bauwens, S. Richter, R. Wellum, Y. 
Aregbe, An inter-calibration campaign using various selected Pu spike isotopic reference materials, J. Radioanal. Nucl. 
Chem., 286, 449-454, 2010 

33   R. Jakopič, Y. Aregbe, S. Richter, E. Zuleger, S. Mialle, S. D. Balsley, U. Repinc and J. Hiess, Verification measurements of 

the IRMM-1027 and the IAEA large-sized dried (LSD) spikes, J. Radioanal. Nucl. Chem., 311, 1781-1791, 2017 

34   JCGM 200:2012, International vocabulary of metrology – Basic and general concepts and associated terms (VIM), 2012 

35   R. Jakopič, J. Bauwens, R. Buják, R. Eykens, C. Hennessy, F. Kehoe, S. Mialle, C. Venchiarutti, S. Richter, Y. Aregbe, Preparation 

and certification of Large-Sized Dried (LSD) spike IRMM-1027p, EUR 26520 EN, 2014 

36   R. Kessel, M. Berglund, R. Wellum, Application of consistency checking to evaluation of uncertainty in multiple replicate 

measurements, Accred. Qual. Assur., 13, 293-298, 2008. 

37   Metrodata GmbH, GUM Workbench, The Tool for Expression of Uncertainty in Measurement (user manual for version 1.3, 

2.3 and 2.4 English ed.), 2011 

38   H. Vesper, H. Emons, M. Gnezda, C. P. Jain, W. G. Miller, R. Rej, G. Schumann, J. Tate, L. Thienpont, J. E. Vaks, Characterization 
and Qualification of Commutable Reference Materials for Laboratory Medicine; Approved Guideline, CLSI document C53-
A, Clinical and Laboratory Standards Institute, Wayne, PA, USA, 2010 

32 

 
 
List of abbreviations and definitions 

ANOVA  

Analysis of variance 

BIPM 

c 

CAB 

Bureau International des Poids et Mesures (International Bureau of Weights and Measures) 

amount of substance concentration 

Cellulose acetate butyrate 

CETAMA 

Commission d'Etablissement des Méthodes d'Analyse  

CI 

CLSI 

CMC 

CRM 

DOP 

EC 

Confidence interval 

Clinical and Laboratory Standards Institute 

Carboxymethyl cellulose 

Certified reference material 

Dioctyl phthalate 

European Commission 

ESARDA 

European Safeguards Research and Development Association 

GUM 

IAEA 

IDMS 

Guide to the Expression of Uncertainty in Measurement  

International Atomic Energy Agency 

Isotope dilution mass spectrometry 

ID-TIMS 

Isotope dilution thermal ionisation mass spectrometry 

ISO 

ITVs 

JRC 

k 

LSD 

m 

M 

International Organization for Standardization 

International Target Values 

Joint Research Centre of the European Commission 

Coverage factor 

Large-Sized dried 

Mass 

Molar mass 

MSbetween 

MSwithin  

Mean of squares between-unit from an ANOVA 

Mean of squares within-unit from an ANOVA 

n 

NBL 

NML 

p.a. 

Rb 

Rx 

Ry 

rel 

REML 

RM 

s 

amount of substance 

New Brunswick laboratory 

Nuclear Material Laboratory 

pro analysis 

Isotope amount ratio in the blend 

Isotope amount ratio in the un-spiked sample 

Isotope amount ratio in the spike 

Index denoting relative figures (uncertainties etc.) 

Restricted maximum likelihood 

Reference material 

Standard deviation 

33 

 
sbb

SI 

sip 

t1/2 

TE 

TIMS 

u 

U 

u*

bb  

ubb 

uchar  

uCRM 

UCRM  

ults 

usts 

Between-unit standard deviation; an additional index "rel" is added when appropriate 

International System of Units 

(Standard deviation associated with) Method intermediate precision 

Half life 

Total evaporation 

Thermal Ionisation Mass Spectrometry 

Standard uncertainty  

Expanded uncertainty 

Standard uncertainty related to a maximum between-unit inhomogeneity that could be hidden 
by method repeatability; an additional index "rel" is added as appropriate 

Standard uncertainty related to a possible between-unit inhomogeneity;  an additional index "rel" 
is added as appropriate 

Standard uncertainty of the material characterisation; an additional index "rel" is added as 
appropriate 

Combined standard uncertainty of the certified value; an additional index "rel" is added as 
appropriate 

Expanded uncertainty of the certified value; an additional index "rel" is added as appropriate 

Standard uncertainty of the long-term stability; an additional index "rel" is added as appropriate 

Standard uncertainty of the short-term stability; an additional index "rel" is added as appropriate 

Arithmetic mean 

Degrees of freedom of MSwithin 

34 

yMSwithin 
 
 
 
 
 
 
 
List of figures 

Figure 1 Starting materials for the preparation of IRMM-1027v LSD spikes: a) one of the electropolished Pu MP2 
metal b) etched U NBL PO CRM 116-A metal and c) U EC NRM 101 metal (Source: EC JRC G.2) ...................................... 10 
Figure 2 Dissolution of Pu and U metals: a) MP2 dissolution in HCl, b) flask from 2a after adding HNO3 and U NBL 
PO CRM 116-A, c) flask from 2b after adding U EC NRM 101 (Source: EC JRC G.2) .................................................................. 11 
Figure 3 Units of IRMM-1027v LSD spike: a) treated with CAB/DOP and b) treated with CMC (Source: EC JRC G.2) 12 
Figure 4 Preparation of IRMM-1027v LSD spikes (Source: EC JRC G.2) ............................................................................................. 12 
Figure 5 Securing the test sample on the transport simulator (Source: EC JRC G.2) .................................................................. 17 
Figure 6 The programmed acceleration versus frequency profile (green line) and the control signal (blue line). Orange 
lines represent low and high alarm limits. Red lines represent low and high abort limits. ..................................................... 17 
Figure 7 IRMM-1027v CRM units embedded into CMC matrix before (top) and after (bottom) the transport simulation.
.................................................................................................................................................................................................................................................... 18 
Figure  8  IRMM-1027v  CRM  units  embedded  into  CAB/DOP matrix  before  (top)  and  after  (bottom)  the  transport 
simulation. (Please, note that the order of the units changed.) .............................................................................................................. 19 
Figure  9  Uranium  isotope  ratio  verification  measurements  for  a)  n(235U)/n(238U)  b)  n(234U)/n(238U)  and  c) 
n(236U)/n(238U). Symbol codes: triangle – JRC-GE, circle – IAEA-SGAS, square – JRC-KA. Colour codes: orange – aliquot, 
red – CAB/DOP, blue – CMC. Error bars show the expanded uncertainties (For JRC-GE results coverage factors are 
based on the t-distribution for the associated effective degrees of freedom that corresponds to a level of confidence 
of about 95 %). (Source: EC JRC G.2, IAEA-SGAS, EC JRC G.II.6.) ........................................................................................................... 22 
Figure  10  Plutonium  isotope  ratio  verification  measurements  for  a)  n(240Pu)/n(239Pu)  (TIMS)  b)  n(238Pu)/n(239Pu) 
(alpha-spectrometry) and c) n(241Pu)/n(239Pu) (TIMS) and d) n(242Pu)/n(239Pu) (TIMS) ratios. Symbol codes: triangle – 
JRC-GE, circle – IAEA-SGAS, square – JRC-KA. Colour codes: orange – aliquot, red – CAB/DOP, blue – CMC. Error bars 
show  the  expanded  uncertainties  (For  JRC-GE  results  coverage  factors  are  based  on  the  t-distribution  for  the 
associated effective degrees of freedom that corresponds to a level of confidence of about 95 %). (Source: EC JRC 
G.2, IAEA-SGAS, EC JRC G.II.6.) .................................................................................................................................................................................. 23 
Figure  11  The  amount  content  of  235U  in  the  selected  vials  of  IRMM-1027v  measured  by  ID-TIMS  at  JRC-GE 
expressed as the relative difference to the gravimetric value. Colour codes: red – CAB/DOP, blue – CMC. Error bars 
show  the  relative  expanded  uncertainties  (coverage  factors  are  based  on  the  t-distribution  for  the  associated 
effective degrees of freedom that corresponds to a level of confidence of about 95 %). Red dotted lines show the 
combined  relative  expanded  uncertainty  %)  assigned  to  the  gravimetric  value  (coverage  factor  k  =  2  that 
corresponds to a level of confidence of about 95 (Source: EC JRC G.2.) ........................................................................................... 25 
Figure 12 The amount content of 238U, U assay or U mass content for the selected units of IRMM-1027v measured 
by ID-TIMS. Symbol codes: triangle – JRC-GE (238U amount content), circle – IAEA-SGAS (U assay), square – JRC-KA 
(U mass per unit). Colour codes: red – CAB/DOP, blue – CMC. Error bars show the relative expanded uncertainties 
(For JRC-GE results coverage factors are based on the t-distribution for the associated effective degrees of freedom 
that corresponds to a level of confidence of about 95 %). Red dotted lines show the combined relative expanded 
uncertainty assigned to the gravimetric value (coverage factor k = 2 that corresponds to a level of confidence of 
about 95 %) (Source: EC JRC G.2, IAEA-SGAS, EC JRC G.II.6.) .................................................................................................................. 26 
Figure 13 The amount content of 239Pu, Pu assay or Pu mass content in the selected units of IRMM-1027v measured 
by ID-TIMS expressed as the relative difference from the gravimetric value. Symbol codes: triangle – JRC-GE (239Pu 
amount content), circle – IAEA-SGAS (Pu assay), square – JRC-KA (Pu mass per unit). Colour codes: red – CAB/DOP, 
blue – CMC. Error bars show the relative expanded uncertainties (For JRC-GE results coverage factors are based on 
the t-distribution for the associated effective degrees of freedom that corresponds to a level of confidence of about 
95  %).  Red  dotted  lines  show  the  combined  relative  expanded  uncertainty  assigned  to  the  gravimetric  value 
(coverage factor k = 2 that corresponds to a level of confidence of about 95 %) (Source: EC JRC G.2, IAEA-SGAS, EC 
JRC G.II.6.) ............................................................................................................................................................................................................................. 26 
Figure 14 Verification results of the IRMM-1027v mother solution by IDMS on the a) 235U, b) 238U and c) 239Pu amount 
contents. Red dashed lines show the relative expanded uncertainty of the gravimetric value with a coverage factor 
k = 2 with the exception of 235U amount content and mass fraction values, which have a coverage factor k = 2.3 
(dfeff  =  9).  Blue  lines  show  the  mean  ID-TIMS  values  and  the  blue  shaded  area  represents  their  expanded 
uncertainties with a coverage factor k = 2. ....................................................................................................................................................... 75 

35 

 
Figure 15 The amount content of  235U from homogeneity study for the 33 replicate measurements (18 selected 
units, 3 replicates each) are shown as a function of the analytical sequence. No significant trend at the 95% CI was 
observed. ............................................................................................................................................................................................................................... 76 
Figure 16 The amount content of  235U from homogeneity study for the 33 replicate measurements (11 selected 
units, 3 replicates each) are shown as a function of the filling sequence. The x positions are slightly ‘dodged’ to 
make overlapping data visible. Significant trend at the 95% CI was observed (p<0.05). ........................................................ 76 
Figure 17 The amount content of  238U from homogeneity study for the 33 replicate measurements (11 selected 
units, 3 replicates each) are shown as a function of the analytical sequence. No significant trend at the 95% CI was 
observed. ............................................................................................................................................................................................................................... 77 
Figure 18 The amount content of  238U from homogeneity study for the 33 replicate measurements (11 selected 
units, 3 replicates each) are shown as a function of the filling sequence. The positions are slightly ‘dodged’ to make 
overlapping data visible. No significant trend at the 95% CI was observed. .................................................................................. 77 
Figure 19 The normalised amount content of 239Pu from homogeneity study for the 33 replicate measurements (11 
selected units, 3 replicates each) are shown as a function of the analytical sequence. No significant trend at the 
95% CI was observed. ................................................................................................................................................................................................... 78 
Figure 20 The normalised amount content of 239Pu from homogeneity study for the 33 replicate measurements (11 
selected units, 3 replicates each) are shown as a function of the filling sequence. The positions are slightly ‘dodged’ 
to make overlapping data visible. No significant trend at the 95% CI was observed. ............................................................... 78 
Figure 21 Tukey’s boxplot representation of day-to-day differences for a) 235U b) 238U and c) 239Pu amount contents 
(the  latter  before  normalisation).  The  boxes  represent  the  interquartile  range  (IQR)  between  the  first  and  third 
quartile,  the  whiskers  represent  either  the  extremes  or  the  ‘fences’  (1.5*IQR)  and  the  individual  dots  represent 
outliers. .................................................................................................................................................................................................................................. 79 

36 

 
 
 
List of tables 

Table 1 Results of the statistical evaluation of the homogeneity studies of the amount content of  235U,  238U and 
239Pu in IRMM-1027v (Source: EC JRC G.2) ........................................................................................................................................................ 14 
Table 2 Results of the homogeneity studies of the amount content in IRMM-1027v (Source: EC JRC G.2) .................. 15 
Table 3 The programmed acceleration versus frequency profile .......................................................................................................... 17 
Table 4 Gravimetric mixing to prepare the mother solution of IRMM-1027v (Source: EC JRC G.2) ................................... 20 
Table 5 Uncertainty budgets for the masses of 235U, 238U and 239Pu in the gravimetric mixture in the first unit #1 of 
IRMM-1027v as an example. The main uncertainty contributions associated to the characterisation are highlighted. 
(Source: EC JRC G.2) ........................................................................................................................................................................................................ 21 
Table 6 Results of the compatibility evaluation for the isotope ratios (Source: EC JRC G.2, IAEA-SGAS, EC JRC G.II.6)
.................................................................................................................................................................................................................................................... 23 
Table 7 The U and Pu isotope amount ratios and their relative standard uncertainties from the characterisation 
assessment of IRMM-1027v (Source: EC JRC G.2) ......................................................................................................................................... 24 
Table 8 Results of the compatibility evaluation for the 235U, 238U and 239Pu amount content (Source: EC JRC G.2). 27 
Table 9 Results of the compatibility evaluation for the U and Pu assay (Source: IAEA-SGAS) ............................................. 27 
Table 10 Results of the compatibility evaluation for the U and Pu mass per unit (Source: EC JRC G.II.6) ..................... 27 
Table 11 Exemplary representation of certified masses and their uncertainties in unit #1 of IRMM-1027v as an 
example (Source: EC JRC G.2) .................................................................................................................................................................................... 28 

37 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Annexes 

Annex 1 The certified masses of 235U, 238U and 239Pu per unit of IRMM-1027v ........................................................................... 39 
Annex 2 The certificate of EC NRM 101 uranium metal ............................................................................................................................. 58 
Annex 3 The certificate of isotopic composition of EC NRM 101 .......................................................................................................... 59 
Annex 4 The certificate of NBL PO CRM 116-A uranium metal.............................................................................................................. 60 
Annex 5 The certificate of CETAMA MP2 plutonium metal........................................................................................................................ 63 
Annex 6 The certificate of plutonium isotope abundances of CETAMA MP2 ................................................................................... 67 
Annex 7 The certificate of uranium amount content and isotope abundances of CETAMA MP2 ......................................... 69 
Annex 8 The certificate of IRMM-046c ................................................................................................................................................................. 72 
Annex 9 IRMM-1027v mother solution verification ....................................................................................................................................... 75 
Annex 10 Results of the homogeneity assessment for IRMM-1027v ................................................................................................. 76 
Annex 11 The weighing certificate of the aliquots of dispensed solution of IRMM-1027v per unit before drying .... 80 
Annex 12 The weighing certificate for the preparation of the mother solution of IRMM-1027v ........................................ 93 
Annex 13 Uncertainty budget for the uranium gravimetric mixture of IRMM-1027v ................................................................ 95 
Annex 14 Uncertainty budget for the plutonium gravimetric mixture of IRMM-1027v .......................................................... 116 
Annex 15 The weighing certificate of the blend mixtures for the confirmation measurements of 235U, 238U and 239Pu 
amount content by ID-TIMS using IRMM-046c. ............................................................................................................................................ 132 
Annex 16 The internal test reports (#4589 and #4662) for the selected units of IRMM-1027v. (Typo: the date of the 
first set of IDMS samples was 20/02/2020 and not 02/02/2020). ................................................................................................... 134 

38 

 
 
 
 
Annex 1 The certified masses of 235U, 238U and 239Pu per unit of IRMM-1027v 

238U 

235U 

239Pu 

Unit # 

001 

002 

003 

004 

005 

006 

007 

008 

009 

010 

011 

012 

013 

014 

015 

016 

017 

018 

019 

020 

021 

022 

023 

024 

025 

026 

027 

028 

029 

030 

031 

032 

033 

034 

035 

036 

037 

038 

039 

040 

041 

042 

043 

044 

045 

046 

047 

048 

049 

Organic 
substance 
CAB/DOP 

CAB/DOP 

Mass 1) 
[mg] 
43.142 

43.736 

CAB/DOP 

43.218 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

43.041 

43.060 

43.052 

43.124 

43.698 

44.059 

43.857 

43.206 

43.062 

43.873 

43.748 

43.190 

44.071 

43.845 

43.895 

43.897 

43.982 

43.874 

43.788 

43.219 

43.793 

43.098 

43.233 

43.015 

43.710 

43.190 

43.762 

43.259 

43.778 

43.124 

43.829 

43.190 

43.949 

43.918 

43.015 

43.753 

43.271 

43.667 

43.194 

43.155 

43.836 

43.131 

42.988 

43.724 

43.188 

43.721 

Uncertainty 2) 
[mg] 
0.023 

0.024 

0.023 

0.023 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.023 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.023 

0.023 

0.024 

0.023 

0.023 

0.024 

0.023 

0.024 

Mass 1) 
[mg] 
10.3301 

10.4725 

10.3483 

10.3061 

10.3107 

10.3086 

10.3260 

10.4634 

10.5499 

10.5014 

10.3454 

10.3111 

10.5052 

10.4754 

10.3417 

10.5527 

10.4985 

10.5105 

10.5110 

10.5312 

10.5056 

10.4849 

10.3487 

10.4861 

10.3198 

10.3520 

10.2999 

10.4663 

10.3417 

10.4787 

10.3583 

10.4824 

10.3260 

10.4948 

10.3417 

10.5234 

10.5159 

10.2999 

10.4766 

10.3612 

10.4559 

10.3425 

10.3334 

10.4965 

10.3276 

10.2933 

10.4696 

10.3413 

10.4687 

39 

Uncertainty 2) 
[mg] 
0.0052 

0.0052 

0.0052 

0.0051 

0.0051 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

Mass 1) 
[mg] 
1.7711 

1.7955 

1.7742 

1.7670 

1.7678 

1.7674 

1.7704 

1.7940 

1.8088 

1.8005 

1.7738 

1.7679 

1.8011 

1.7960 

1.7731 

1.8093 

1.8000 

1.8021 

1.8021 

1.8056 

1.8012 

1.7977 

1.7743 

1.7979 

1.7694 

1.7749 

1.7659 

1.7945 

1.7731 

1.7966 

1.7759 

1.7972 

1.7704 

1.7994 

1.7731 

1.8043 

1.8030 

1.7659 

1.7962 

1.7764 

1.7927 

1.7733 

1.7717 

1.7996 

1.7707 

1.7648 

1.7950 

1.7730 

1.7949 

Uncertainty 2) 
[mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
050 

CAB/DOP 

44.147 

0.024 

10.5710 

0.0052 

1.8124 

0.0013 

238U 

235U 

239Pu 

Unit # 

051 

052 

053 

054 

055 

056 

057 

058 

059 

060 

061 

062 

063 

064 

065 

066 

067 

068 

069 

070 

071 

072 

073 

074 

075 

076 

077 

078 

079 

080 

081 

082 

083 

084 

085 

086 

087 

088 

089 

090 

091 

092 

093 

094 

095 

096 

097 

098 

099 

100 

Organic 
substance 
CAB/DOP 

CAB/DOP 

Mass 1) 
[mg] 
43.733 

43.171 

CAB/DOP 

43.829 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

43.871 

43.213 

43.015 

43.050 

43.043 

43.895 

43.033 

43.902 

43.911 

43.838 

43.968 

43.045 

43.641 

43.237 

43.069 

43.805 

42.995 

43.009 

43.923 

43.937 

43.655 

43.266 

42.976 

43.816 

43.816 

43.938 

43.035 

43.695 

43.975 

43.798 

43.684 

44.042 

43.658 

43.940 

43.098 

43.788 

43.626 

43.874 

43.200 

43.565 

43.204 

43.510 

43.256 

43.653 

43.702 

43.206 

43.731 

Uncertainty 2) 
[mg] 
0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.023 

0.024 

0.023 

0.023 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

Uncertainty 2) 
[mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0051 

0.0051 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0051 

0.0052 

0.0051 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

Mass 1) 
[mg] 
1.7954 

1.7723 

1.7994 

1.8011 

1.7740 

1.7659 

1.7674 

1.7671 

1.8021 

1.7667 

1.8023 

1.8027 

1.7997 

1.8050 

1.7672 

1.7916 

1.7750 

1.7681 

1.7984 

1.7651 

1.7657 

1.8032 

1.8038 

1.7922 

1.7762 

1.7643 

1.7988 

1.7988 

1.8038 

1.7667 

1.7938 

1.8053 

1.7981 

1.7934 

1.8081 

1.7923 

1.8039 

1.7694 

1.7977 

1.7910 

1.8012 

1.7735 

1.7885 

1.7737 

1.7862 

1.7758 

1.7921 

1.7941 

1.7738 

1.7953 

Mass 1) 
[mg] 
10.4716 

10.3371 

10.4948 

10.5047 

10.3471 

10.2999 

10.3082 

10.3065 

10.5105 

10.3040 

10.5122 

10.5143 

10.4969 

10.5279 

10.3069 

10.4497 

10.3529 

10.3127 

10.4890 

10.2949 

10.2982 

10.5172 

10.5205 

10.4530 

10.3599 

10.2904 

10.4915 

10.4915 

10.5209 

10.3045 

10.4625 

10.5296 

10.4874 

10.4601 

10.5457 

10.4538 

10.5213 

10.3198 

10.4849 

10.4460 

10.5056 

10.3442 

10.4315 

10.3450 

10.4183 

10.3574 

10.4526 

10.4642 

10.3454 

10.4712 

40 

Uncertainty 2) 
[mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
238U 

Organic 
substance 
CMC 

Mass 1)  
[mg] 
43.641 

Uncertainty 2) 
 [mg] 
0.023 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 
CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

43.733 

43.252 

43.717 

43.764 

43.940 

43.676 

43.961 

43.726 

43.733 

43.781 

43.007 

43.581 

43.095 

43.755 

43.829 

43.691 

43.793 

43.748 

43.840 

43.887 

43.624 

43.790 

43.620 

43.983 

43.776 

43.705 

43.743 

43.762 

43.698 

43.802 

43.778 

43.632 

43.712 

43.178 

43.791 

43.639 

43.734 

43.800 

43.517 

43.190 

43.717 

43.705 

43.722 

43.769 
43.579 

43.117 

43.600 

43.000 

43.470 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 
0.023 

0.023 

0.023 

0.023 

0.023 

Unit # 

101 

102 

103 

104 

105 

106 

107 

108 

109 

110 

111 

112 

113 

114 

115 

116 

117 

118  

119 

120 

121 

122 

123 

124 

125 

126 

127 

128 

129 

130 

131 

132 

133 

134 

135 

136 

137 

138 

139 

140 

141 

142 

143 

144 

145 
146 

147 

148 

149 

150 

Mass 1)   
[mg] 
10.4497 

10.4716 

10.3566 

10.4679 

10.4791 

10.5213 

10.4580 

10.5263 

10.4700 

10.4716 

10.4832 

10.2978 

10.4352 

10.3189 

10.4770 

10.4948 

10.4617 

10.4861 

10.4754 

10.4973 

10.5085 

10.4456 

10.4853 

10.4447 

10.5316 

10.4820 

10.4650 

10.4741 

10.4787 

10.4634 

10.4882 

10.4824 

10.4476 

10.4667 

10.3388 

10.4857 

10.4493 

10.4721 

10.4878 

10.4199 

10.3417 

10.4679 

10.4650 

10.4692 

10.4803 
10.4348 

10.3243 

10.4398 

10.2962 

10.4087 

41 

235U 

Uncertainty 2) 
 [mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 
0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

Mass 1) 
 [mg] 
1.7916 

1.7954 

1.7757 

1.7948 

1.7967 

1.8039 

1.7930 

1.8048 

1.7951 

1.7954 

1.7974 

1.7656 

1.7891 

1.7692 

1.7963 

1.7994 

1.7937 

1.7979 

1.7960 

1.7998 

1.8017 

1.7909 

1.7977 

1.7908 

1.8057 

1.7972 

1.7943 

1.7958 

1.7966 

1.7940 

1.7982 

1.7972 

1.7913 

1.7945 

1.7726 

1.7978 

1.7916 

1.7955 

1.7982 

1.7865 

1.7731 

1.7948 

1.7943 

1.7950 

1.7969 
1.7891 

1.7701 

1.7899 

1.7653 

1.7846 

239Pu 

Uncertainty 2) 
 [mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
238U 

235U 

239Pu 

Unit # 

151 

152 

153 

154 

155 

156 

157 

158 

159 

160 

161 

162 

163 

164 

165 

166 

167 

168 

169 

170 

171 

172 

173 

174 

175 

176 

177 

178 

179 

180 

181 

182 

183 

184 

185 

186 

187 

188 

189 

190 

191 

192 

193 

194 

195 

196 

197 

198 

199 

200 

Organic 
substance 
CAB/DOP 

Mass 1)  
[mg] 
43.169 

Uncertainty 2)  
[mg] 
0.023 

CAB/DOP 

43.691 

CAB/DOP 

43.745 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

43.698 

43.783 

43.589 

43.931 

43.745 

43.710 

43.700 

43.728 

43.760 

43.501 

43.926 

43.722 

43.864 

43.627 

43.681 

43.835 

43.634 

43.778 

43.702 

43.632 

43.821 

43.712 

43.747 

43.636 

43.674 

43.650 

43.135 

43.515 

43.828 

43.781 

43.690 

43.702 

43.591 

43.731 

43.902 

43.584 

43.895 

43.498 

43.883 

43.731 

43.598 

43.850 

43.809 

43.695 

43.752 

43.672 

43.850 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

Mass 1)  
[mg] 
10.3367 

10.4617 

10.4745 

10.4634 

10.4836 

10.4373 

10.5192 

10.4745 

10.4663 

10.4638 

10.4704 

10.4783 

10.4162 

10.5180 

10.4692 

10.5031 

10.4464 

10.4592 

10.4961 

10.4481 

10.4824 

10.4642 

10.4476 

10.4927 

10.4667 

10.4749 

10.4485 

10.4576 

10.4518 

10.3285 

10.4195 

10.4944 

10.4832 

10.4613 

10.4642 

10.4377 

10.4712 

10.5122 

10.4361 

10.5105 

10.4154 

10.5076 

10.4712 

10.4394 

10.4998 

10.4898 

10.4625 

10.4762 

10.4572 

10.4998 

42 

Uncertainty 2) 
 [mg] 
0.0052 

Mass 1)  
[mg] 
1.7723 

Uncertainty 2) 
 [mg] 
0.0013 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

1.7937 

1.7959 

1.7940 

1.7974 

1.7895 

1.8035 

1.7959 

1.7945 

1.7940 

1.7952 

1.7965 

1.7859 

1.8033 

1.7950 

1.8008 

1.7911 

1.7933 

1.7996 

1.7913 

1.7972 

1.7941 

1.7913 

1.7990 

1.7945 

1.7960 

1.7914 

1.7930 

1.7920 

1.7708 

1.7865 

1.7993 

1.7974 

1.7936 

1.7941 

1.7896 

1.7953 

1.8023 

1.7893 

1.8021 

1.7857 

1.8016 

1.7953 

1.7899 

1.8002 

1.7985 

1.7938 

1.7962 

1.7929 

1.8002 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
Unit # 

201 

202 

203 

204 

205 

206 

207 

208 

209 

210 

211 

212 

213 

214 

215 

216 

217 

218 

219 

220 

221 

222 

223 

224 

225 

226 

227 

228 

229 

230 

231 

232 

233 

234 

235 

236 

237 

238 

239 

240 

241 

242 

243 

244 

245 

246 

247 

248 

249 

250 

Organic 
substance 
CMC 

CAB/DOP 

Mass 1) 
 [mg] 
43.613 

43.712 

CAB/DOP 

43.683 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

43.745 

43.726 

43.703 

43.506 

43.928 

43.567 

43.798 

42.995 

43.646 

43.774 

43.667 

43.613 

43.567 

43.135 

43.511 

43.781 

43.660 

43.741 

43.864 

43.593 

43.529 

43.698 

43.899 

43.717 

43.703 

43.717 

43.650 

43.575 

43.076 

43.651 

43.729 

43.696 

43.690 

43.657 

43.828 

43.626 

43.589 

43.847 

43.762 

43.634 

43.605 

43.771 

43.577 

43.743 

43.757 

43.610 

43.150 

238U 

Uncertainty 2) 
 [mg] 
0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

235U 

Uncertainty 2) 
 [mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

Mass 1)  
[mg] 
10.4431 

10.4667 

10.4596 

10.4745 

10.4700 

10.4646 

10.4174 

10.5184 

10.4319 

10.4874 

10.2949 

10.4509 

10.4816 

10.4559 

10.4431 

10.4319 

10.3285 

10.4187 

10.4832 

10.4543 

10.4737 

10.5031 

10.4381 

10.4228 

10.4634 

10.5114 

10.4679 

10.4646 

10.4679 

10.4518 

10.4340 

10.3144 

10.4522 

10.4708 

10.4629 

10.4613 

10.4534 

10.4944 

10.4460 

10.4373 

10.4990 

10.4787 

10.4481 

10.4410 

10.4807 

10.4344 

10.4741 

10.4774 

10.4423 

10.3322 

43 

Mass 1) 
 [mg] 
1.7905 

1.7945 

1.7933 

1.7959 

1.7951 

1.7942 

1.7861 

1.8034 

1.7886 

1.7981 

1.7651 

1.7918 

1.7971 

1.7927 

1.7905 

1.7886 

1.7708 

1.7863 

1.7974 

1.7924 

1.7957 

1.8008 

1.7896 

1.7870 

1.7940 

1.8022 

1.7948 

1.7942 

1.7948 

1.7920 

1.7889 

1.7684 

1.7921 

1.7952 

1.7939 

1.7936 

1.7923 

1.7993 

1.7910 

1.7895 

1.8001 

1.7966 

1.7913 

1.7901 

1.7970 

1.7890 

1.7958 

1.7964 

1.7904 

1.7715 

239Pu 

Uncertainty 2)  
[mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
Unit # 

251 

252 

253 

254 

255 

256 

257 

258 

259 

260 

261 

262 

263 

264 

265 

266 

267 

268 

269 

270 

271 

272 

273 

274 

275 

276 

277 

278 

279 

280 

281 

282 

283 

284 

285 

286 

287 

288 

289 

290 

291 

292 

293 

294 

295 

296 

297 

298 

299 

300 

238U 

Organic 
substance 
CAB/DOP 

Mass 1)  
[mg] 
43.579 

Uncertainty 2) 
 [mg] 
0.023 

CAB/DOP 

43.551 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

43.074 

43.627 

43.683 

43.662 

43.038 

43.562 

43.646 

43.660 

43.631 

43.743 

43.639 

43.169 

43.553 

43.686 

43.731 

43.717 

43.669 

43.641 

43.024 

43.598 

43.662 

43.807 

43.664 

43.634 

43.638 

43.776 

43.683 

43.684 

43.565 

43.876 

43.683 

43.582 

43.752 

43.752 

43.807 

43.641 

43.717 

43.482 

43.107 

43.710 

43.702 

43.539 

43.738 

43.556 

43.086 

43.586 

43.544 

43.857 

0.023 

0.023 

0.023 

0.024 

0.023 

0.023 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

Mass 1)  
 [mg] 
10.4348 

10.4282 

10.3140 

10.4464 

10.4596 

10.4547 

10.3053 

10.4307 

10.4509 

10.4543 

10.4472 

10.4741 

10.4493 

10.3367 

10.4286 

10.4605 

10.4712 

10.4679 

10.4563 

10.4497 

10.3020 

10.4394 

10.4547 

10.4894 

10.4551 

10.4481 

10.4489 

10.4820 

10.4596 

10.4601 

10.4315 

10.5060 

10.4596 

10.4356 

10.4762 

10.4762 

10.4894 

10.4497 

10.4679 

10.4116 

10.3218 

10.4663 

10.4642 

10.4253 

10.4729 

10.4294 

10.3169 

10.4365 

10.4265 

10.5014 

44 

235U 

Uncertainty 2) 
 [mg] 
0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

Mass 1) 
 [mg] 
1.7891 

1.7879 

1.7684 

1.7911 

1.7933 

1.7925 

1.7669 

1.7884 

1.7918 

1.7924 

1.7912 

1.7958 

1.7916 

1.7723 

1.7880 

1.7935 

1.7953 

1.7948 

1.7928 

1.7916 

1.7663 

1.7899 

1.7925 

1.7984 

1.7926 

1.7913 

1.7915 

1.7972 

1.7933 

1.7934 

1.7885 

1.8013 

1.7933 

1.7892 

1.7962 

1.7962 

1.7984 

1.7916 

1.7948 

1.7851 

1.7697 

1.7945 

1.7941 

1.7874 

1.7956 

1.7882 

1.7689 

1.7894 

1.7877 

1.8005 

239Pu 

Uncertainty 2)  
[mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
Unit # 

301 

302 

303 

304 

305 

306 

307 

308 

309 

310 

311 

312 

313 

314 

315 

316 

317 

318 

319 

320 

321 

322 

323 

324 

325 

326 

327 

328 

329 

330 

331 

332 

333 

334 

335 

336 

337 

338 

339 

340 

341 
3425) 
3435) 

344 
3455) 

346 

347 

348 

349 

350 

Organic 
substance 
CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

Mass 1) 
 [mg] 
43.584 

43.100 

43.544 

43.638 

43.657 

43.076 

43.626 

43.726 

43.546 

43.766 

43.840 

43.613 

43.741 

43.558 

43.769 

43.709 

43.791 

43.653 

43.076 

43.600 

43.487 

43.874 

43.579 

43.880 

43.536 

43.138 

43.541 

43.619 

43.686 

43.733 

43.081 

43.617 

43.729 

43.674 

43.715 

43.710 

43.774 

43.690 

43.598 

43.747 

43.797 

43.734 

43.658 

43.728 

43.601 

43.838 

43.722 

43.660 

43.641 

43.100 

238U 

Uncertainty 2) 
 [mg] 
0.023 

0.023 

0.023 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

235U 

Uncertainty 2) 
 [mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

Mass 1)  
 [mg] 
10.4361 

10.3202 

10.4265 

10.4489 

10.4534 

10.3144 

10.4460 

10.4700 

10.4269 

10.4795 

10.4973 

10.4431 

10.4737 

10.4298 

10.4803 

10.4658 

10.4857 

10.4526 

10.3144 

10.4398 

10.4129 

10.5056 

10.4348 

10.5068 

10.4245 

10.3293 

10.4257 

10.4443 

10.4605 

10.4716 

10.3156 

10.4439 

10.4708 

10.4576 

10.4675 

10.4663 

10.4816 

10.4613 

10.4394 

10.4749 

10.4870 

10.4721 

10.4538 

10.4704 

10.4402 

10.4969 

10.4692 

10.4543 

10.4497 

10.3202 

45 

Mass 1) 
 [mg] 
1.7893 

1.7694 

1.7877 

1.7915 

1.7923 

1.7684 

1.7910 

1.7951 

1.7877 

1.7967 

1.7998 

1.7905 

1.7957 

1.7882 

1.7969 

1.7944 

1.7978 

1.7921 

1.7684 

1.7899 

1.7853 

1.8012 

1.7891 

1.8014 

1.7873 

1.7710 

1.7875 

1.7907 

1.7935 

1.7954 

1.7686 

1.7906 

1.7952 

1.7930 

1.7947 

1.7945 

1.7971 

1.7936 

1.7899 

1.7960 

1.7980 

1.7955 

1.7923 

1.7952 

1.7900 

1.7997 

1.7950 

1.7924 

1.7916 

1.7694 

239Pu 

Uncertainty 2)  
[mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
Unit # 

351 

352 

353 

354 

355 

356 

357 

358 

359 

360 

361 

362 

363 

364 
3655) 

366 

367 

368 

369 

370 
3715) 

372 

373 
3745) 
3755) 

376 

377 

378 

379 

380 
3815) 

382 
3835) 

384 

385 

386 

387 

388 

389 

390 

391 

392 

393 

394 

395 

396 

397 

398 

399 

400 

238U 

Organic 
substance 
CAB/DOP 

Mass 1)  
[mg] 
43.613 

Uncertainty 2)  
[mg] 
0.023 

CAB/DOP 

43.681 

CAB/DOP 

43.750 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

43.767 

43.665 

42.990 

43.610 

43.823 

43.600 

43.691 

43.752 

43.745 

43.650 

43.695 

43.622 

43.895 

43.703 

43.696 

42.990 

43.513 

43.710 

43.098 

43.596 

43.607 

43.911 

43.662 

43.755 

43.740 

43.670 

43.717 

43.620 

43.690 

43.660 

43.805 

43.788 

43.672 

43.745 

43.581 

43.797 

43.748 

43.676 

43.589 

43.050 

43.710 

43.610 

43.888 

43.529 

43.677 

43.740 

43.035 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

Mass 1)   
[mg] 
10.4431 

10.4592 

10.4758 

10.4799 

10.4555 

10.2937 

10.4423 

10.4932 

10.4398 

10.4617 

10.4762 

10.4745 

10.4518 

10.4625 

10.4452 

10.5105 

10.4646 

10.4629 

10.2937 

10.4191 

10.4663 

10.3198 

10.4389 

10.4414 

10.5143 

10.4547 

10.4770 

10.4733 

10.4567 

10.4679 

10.4447 

10.4613 

10.4543 

10.4890 

10.4849 

10.4572 

10.4745 

10.4352 

10.4870 

10.4754 

10.4580 

10.4373 

10.3082 

10.4663 

10.4423 

10.5089 

10.4228 

10.4584 

10.4733 

10.3045 

46 

235U 

Uncertainty 2) 
 [mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

Mass 1) 
 [mg] 
1.7905 

1.7933 

1.7961 

1.7968 

1.7926 

1.7649 

1.7904 

1.7991 

1.7899 

1.7937 

1.7962 

1.7959 

1.7920 

1.7938 

1.7908 

1.8021 

1.7942 

1.7939 

1.7649 

1.7864 

1.7945 

1.7694 

1.7898 

1.7902 

1.8027 

1.7925 

1.7963 

1.7957 

1.7928 

1.7948 

1.7908 

1.7936 

1.7924 

1.7984 

1.7977 

1.7929 

1.7959 

1.7891 

1.7980 

1.7960 

1.7930 

1.7895 

1.7674 

1.7945 

1.7904 

1.8018 

1.7870 

1.7931 

1.7957 

1.7667 

239Pu 

Uncertainty 2) 
 [mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
Unit # 

401 

402 

403 

404 

405 

406 

407 

408 

409 

410 

411 

412 

413 

414 

415 

416 

417 

418 

419 

420 

421 

422 

423 

424 

425 

426 

427 

428 

429 

430 

431 

432 

433 

434 

435 

436 

437 

438 

439 

440 

441 

442 

443 

444 

445 

446 

447 

448 

449 

450 

Organic 
substance 
CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

Mass 1) 
[mg] 
43.653 

43.755 

43.728 

43.660 

43.624 

43.107 

43.669 

43.643 

43.677 

43.686 

44.011 

43.413 

43.937 

43.646 

43.817 

43.738 

43.643 

43.594 

43.123 

43.470 

43.033 

43.695 

43.588 

43.783 

43.097 

43.636 

43.534 

43.840 

43.769 

43.859 

43.619 

43.772 

43.672 

43.764 

43.688 

43.691 

43.781 

43.717 

43.736 

43.670 

43.766 

43.700 

43.669 

43.710 

43.790 

43.506 

43.892 

43.690 

43.593 

43.976 

238U 

Uncertainty 2) 
[mg] 
0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

235U 

Uncertainty 2) 
[mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

Mass 1) 
[mg] 
10.4526 

10.4770 

10.4704 

10.4543 

10.4456 

10.3218 

10.4563 

10.4501 

10.4584 

10.4605 

10.5383 

10.3951 

10.5205 

10.4509 

10.4919 

10.4729 

10.4501 

10.4385 

10.3256 

10.4087 

10.3040 

10.4625 

10.4369 

10.4836 

10.3194 

10.4485 

10.4241 

10.4973 

10.4803 

10.5018 

10.4443 

10.4812 

10.4572 

10.4791 

10.4609 

10.4617 

10.4832 

10.4679 

10.4725 

10.4567 

10.4795 

10.4638 

10.4563 

10.4663 

10.4853 

10.4174 

10.5097 

10.4613 

10.4381 

10.5300 

47 

Mass 1) 
[mg] 
1.7921 

1.7963 

1.7952 

1.7924 

1.7909 

1.7697 

1.7928 

1.7917 

1.7931 

1.7935 

1.8068 

1.7823 

1.8038 

1.7918 

1.7989 

1.7956 

1.7917 

1.7897 

1.7703 

1.7846 

1.7667 

1.7938 

1.7894 

1.7974 

1.7693 

1.7914 

1.7872 

1.7998 

1.7969 

1.8006 

1.7907 

1.7970 

1.7929 

1.7967 

1.7935 

1.7937 

1.7974 

1.7948 

1.7955 

1.7928 

1.7967 

1.7940 

1.7928 

1.7945 

1.7977 

1.7861 

1.8019 

1.7936 

1.7896 

1.8054 

239Pu 

Uncertainty 2) 
[mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
 
238U 

235U 

239Pu 

Unit # 

451 

452 

453 

454 

455 

456 

457 

458 

459 

460 

461 

462 

463 

464 

465 

466 

467 

468 

469 

470 

471 

472 

473 

474 

475 

476 

477 

478 

479 

480 

481 

482 

483 

484 

485 

486 

487 

488 

489 

490 

491 

492 

493 

494 

495 

496 

497 

498 

499 

500 

Organic 
substance 
CAB/DOP 

Mass 1)  
[mg] 
43.629 

Uncertainty 2)  
[mg] 
0.023 

CAB/DOP 

43.714 

CAB/DOP 

43.738 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

43.710 

43.722 

43.748 

43.715 

43.605 

43.036 

43.709 

43.674 

43.581 

43.752 

43.824 

43.686 

43.786 

43.565 

43.738 

43.076 

43.544 

43.705 

43.833 

43.076 

43.607 

43.724 

43.570 

43.805 

43.669 

43.791 

43.066 

43.672 

43.703 

43.636 

43.869 

43.660 

43.696 

43.745 

43.804 

43.655 

43.734 

43.059 

43.831 

43.499 

43.696 

43.880 

43.691 

43.833 

43.710 

43.679 

43.804 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

Mass 1)   
[mg] 
10.4468 

10.4671 

10.4729 

10.4663 

10.4692 

10.4754 

10.4675 

10.4410 

10.3049 

10.4658 

10.4576 

10.4352 

10.4762 

10.4936 

10.4605 

10.4845 

10.4315 

10.4729 

10.3144 

10.4265 

10.4650 

10.4956 

10.3144 

10.4414 

10.4696 

10.4327 

10.4890 

10.4563 

10.4857 

10.3119 

10.4572 

10.4646 

10.4485 

10.5043 

10.4543 

10.4629 

10.4745 

10.4886 

10.4530 

10.4721 

10.3103 

10.4952 

10.4158 

10.4629 

10.5068 

10.4617 

10.4956 

10.4663 

10.4588 

10.4886 

48 

Uncertainty 2) 
 [mg] 
0.0052 

Mass 1)  
[mg] 
1.7911 

Uncertainty 2)  
[mg] 
0.0013 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

1.7946 

1.7956 

1.7945 

1.7950 

1.7960 

1.7947 

1.7901 

1.7668 

1.7944 

1.7930 

1.7891 

1.7962 

1.7992 

1.7935 

1.7976 

1.7885 

1.7956 

1.7684 

1.7877 

1.7943 

1.7995 

1.7684 

1.7902 

1.7950 

1.7887 

1.7984 

1.7928 

1.7978 

1.7680 

1.7929 

1.7942 

1.7914 

1.8010 

1.7924 

1.7939 

1.7959 

1.7983 

1.7922 

1.7955 

1.7677 

1.7994 

1.7858 

1.7939 

1.8014 

1.7937 

1.7995 

1.7945 

1.7932 

1.7983 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
 
 
 
 
 
Unit # 

501 

502 

503 

504 

505 

506 

507 

508 

509 

510 

511 

512 

513 

514 

515 

516 

517 

518 

519 

520 

521 

522 

523 

524 

525 

526 

527 

528 

529 

530 

531 

532 

533 

534 

535 

536 

537 

538 

539 

540 

541 

542 

543 

544 

545 

546 

547 

548 

549 

550 

Organic 
substance 
CAB/DOP 

CAB/DOP 

Mass 1) 
 [mg] 
43.772 

43.582 

CAB/DOP 

43.095 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

43.515 

43.157 

43.515 

43.829 

43.036 

43.658 

43.715 

43.695 

43.043 

43.631 

43.620 

43.057 

43.722 

43.674 

43.759 

43.702 

43.012 

43.605 

43.807 

43.779 

43.658 

43.800 

43.707 

43.710 

42.983 

43.693 

43.636 

43.817 

43.800 

43.722 

43.745 

43.605 

43.871 

43.707 

43.724 

43.636 

43.764 

43.710 

43.914 

43.816 

43.641 

43.690 

43.741 

43.074 

43.536 

43.703 

43.873 

238U 

Uncertainty 2) 
 [mg] 
0.024 

0.023 

0.023 

0.023 

0.023 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

235U 

239Pu 

Uncertainty 2)  
[mg] 
0.0052 

Mass 1)  
[mg] 
1.7970 

Uncertainty 2) 
 [mg] 
0.0013 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

1.7892 

1.7692 

1.7865 

1.7718 

1.7865 

1.7994 

1.7668 

1.7923 

1.7947 

1.7938 

1.7671 

1.7912 

1.7908 

1.7676 

1.7950 

1.7930 

1.7965 

1.7941 

1.7658 

1.7901 

1.7984 

1.7973 

1.7923 

1.7982 

1.7943 

1.7945 

1.7646 

1.7938 

1.7914 

1.7989 

1.7982 

1.7950 

1.7959 

1.7901 

1.8011 

1.7943 

1.7950 

1.7914 

1.7967 

1.7945 

1.8028 

1.7988 

1.7916 

1.7936 

1.7957 

1.7684 

1.7873 

1.7942 

1.8011 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

Mass 1)   
[mg] 
10.4812 

10.4356 

10.3189 

10.4195 

10.3338 

10.4195 

10.4948 

10.3049 

10.4538 

10.4675 

10.4625 

10.3065 

10.4472 

10.4447 

10.3098 

10.4692 

10.4576 

10.4778 

10.4642 

10.2991 

10.4410 

10.4894 

10.4828 

10.4538 

10.4878 

10.4654 

10.4663 

10.2920 

10.4621 

10.4485 

10.4919 

10.4878 

10.4692 

10.4745 

10.4410 

10.5047 

10.4654 

10.4696 

10.4485 

10.4791 

10.4663 

10.5151 

10.4915 

10.4497 

10.4613 

10.4737 

10.3140 

10.4245 

10.4646 

10.5052 

49 

 
 
 
 
 
Unit # 

551 

552 

553 

554 

555 

556 

557 

558 

559 

560 

561 

562 

563 

564 

565 

566 

567 

568 

569 

570 

571 

572 

573 

574 

575 

576 

577 

578 

579 

580 

581 

582 

583 

584 

585 

586 

587 

588 

589 

590 

591 

592 

593 

594 

595 

596 

597 

598 

599 

600 

Organic 
substance 
CAB/DOP 

CAB/DOP 

Mass 1) 
 [mg] 
43.686 

43.823 

CAB/DOP 

43.793 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

43.724 

43.772 

43.641 

43.767 

43.829 

43.729 

43.740 

43.024 

43.589 

43.771 

43.691 

43.736 

43.771 

42.996 

43.757 

43.757 

43.662 

43.793 

43.683 

43.111 

43.610 

43.788 

43.636 

43.800 

43.721 

43.791 

43.769 

43.759 

43.762 

43.560 

43.036 

43.753 

43.677 

43.076 

43.693 

43.745 

43.807 

43.731 

43.724 

43.817 

43.717 

43.601 

43.866 

43.696 

43.798 

43.797 

43.776 

238U 

Uncertainty 2) 
 [mg] 
0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

Mass 1)  
 [mg] 
10.4605 

10.4932 

10.4861 

10.4696 

10.4812 

10.4497 

10.4799 

10.4948 

10.4708 

10.4733 

10.3020 

10.4373 

10.4807 

10.4617 

10.4725 

10.4807 

10.2954 

10.4774 

10.4774 

10.4547 

10.4861 

10.4596 

10.3227 

10.4423 

10.4849 

10.4485 

10.4878 

10.4687 

10.4857 

10.4803 

10.4778 

10.4787 

10.4303 

10.3049 

10.4766 

10.4584 

10.3144 

10.4621 

10.4745 

10.4894 

10.4712 

10.4696 

10.4919 

10.4679 

10.4402 

10.5035 

10.4629 

10.4874 

10.4870 

10.4820 

50 

235U 

239Pu 

Uncertainty 2) 
 [mg] 
0.0052 

Mass 1)  
[mg] 
1.7935 

Uncertainty 2)  
[mg] 
0.0013 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

1.7991 

1.7979 

1.7950 

1.7970 

1.7916 

1.7968 

1.7994 

1.7952 

1.7957 

1.7663 

1.7895 

1.7970 

1.7937 

1.7955 

1.7970 

1.7652 

1.7964 

1.7964 

1.7925 

1.7979 

1.7933 

1.7698 

1.7904 

1.7977 

1.7914 

1.7982 

1.7949 

1.7978 

1.7969 

1.7965 

1.7966 

1.7883 

1.7668 

1.7962 

1.7931 

1.7684 

1.7938 

1.7959 

1.7984 

1.7953 

1.7950 

1.7989 

1.7948 

1.7900 

1.8009 

1.7939 

1.7981 

1.7980 

1.7972 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
 
Unit # 

601 

602 

603 

604 

605 

606 

607 

608 

609 

610 

611 

612 

613 

614 

615 

616 

617 

618 

619 

620 

621 

622 

623 

624 

625 

626 

627 

628 

629 

630 

631 

632 
6334) 

634 

635 

636 

637 

638 

639 

640 

641 

642 

643 

644 

645 

646 

647 

648 

649 

650 

238U 

Organic 
substance 
CMC 

Mass 1)  
[mg] 
43.764 

Uncertainty 2) 
 [mg] 
0.024 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

N/A 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

43.679 

43.852 

43.712 

43.631 

43.888 

43.883 

43.612 

43.762 

43.655 

43.900 

43.709 

43.795 

43.679 

43.795 

43.804 

43.634 

43.676 

43.128 

43.707 

43.781 

43.698 

43.786 

43.683 

43.776 

43.643 

43.914 

43.686 

43.855 

43.686 

43.776 

43.778 

N/A 

43.774 

43.731 

42.977 

43.650 

43.798 

43.802 

43.755 

43.753 

43.726 

43.728 

43.814 

43.755 

43.748 

42.998 

43.629 

43.757 

43.717 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

N/A 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

Mass 1) 
  [mg] 
10.4791 

10.4588 

10.5002 

10.4667 

10.4472 

10.5089 

10.5076 

10.4427 

10.4787 

10.4530 

10.5118 

10.4658 

10.4865 

10.4588 

10.4865 

10.4886 

10.4481 

10.4580 

10.3268 

10.4654 

10.4832 

10.4634 

10.4845 

10.4596 

10.4820 

10.4501 

10.5151 

10.4605 

10.5010 

10.4605 

10.4820 

10.4824 

N/A 

10.4816 

10.4712 

10.2908 

10.4518 

10.4874 

10.4882 

10.4770 

10.4766 

10.4700 

10.4704 

10.4911 

10.4770 

10.4754 

10.2958 

10.4468 

10.4774 

10.4679 

51 

235U 

Uncertainty 2) 
 [mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

N/A 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

Mass 1) 
 [mg] 
1.7967 

1.7932 

1.8003 

1.7945 

1.7912 

1.8018 

1.8016 

1.7904 

1.7966 

1.7922 

1.8023 

1.7944 

1.7979 

1.7932 

1.7979 

1.7983 

1.7913 

1.7930 

1.7706 

1.7943 

1.7974 

1.7940 

1.7976 

1.7933 

1.7972 

1.7917 

1.8028 

1.7935 

1.8004 

1.7935 

1.7972 

1.7972 

N/A 

1.7971 

1.7953 

1.7644 

1.7920 

1.7981 

1.7982 

1.7963 

1.7962 

1.7951 

1.7952 

1.7987 

1.7963 

1.7960 

1.7652 

1.7911 

1.7964 

1.7948 

239Pu 

Uncertainty 2) 
 [mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

N/A 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
 
 
 
 
 
 
238U 

Organic 
substance 
CMC 

Mass 1)  
[mg] 
43.864 

Uncertainty 2) 
 [mg] 
0.024 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

43.672 

43.821 

43.691 

43.681 

43.743 

43.092 

43.695 

43.748 

43.798 

43.753 

43.826 

43.726 

43.752 

43.767 

43.607 

43.074 

43.696 

43.760 

43.766 

43.705 

43.791 

43.741 

43.769 

43.753 

43.760 

43.738 

43.664 

43.710 

43.835 

43.078 

43.620 

43.724 

43.677 

43.140 

43.591 

43.653 

43.816 

43.057 

43.667 

43.721 

43.653 

43.038 

43.710 

43.012 

43.579 

43.762 

43.809 

43.741 

43.650 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.023 

Unit # 

651 

652 

653 

654 

655 

656 

657 

658 

659 

660 

661 

662 

663 

664 

665 

666 

667 

668 

669 

670 

671 

672 

673 

674 

675 

676 

677 

678 

679 

680 

681 

682 

683 

684 

685 

686 

687 

688 

689 

690 

691 

692 

693 

694 

695 

696 

697 

698 

699 

700 

Mass 1)  
 [mg] 
10.5031 

10.4572 

10.4927 

10.4617 

10.4592 

10.4741 

10.3181 

10.4625 

10.4754 

10.4874 

10.4766 

10.4940 

10.4700 

10.4762 

10.4799 

10.4414 

10.3140 

10.4629 

10.4783 

10.4795 

10.4650 

10.4857 

10.4737 

10.4803 

10.4766 

10.4783 

10.4729 

10.4551 

10.4663 

10.4961 

10.3148 

10.4447 

10.4696 

10.4584 

10.3297 

10.4377 

10.4526 

10.4915 

10.3098 

10.4559 

10.4687 

10.4526 

10.3053 

10.4663 

10.2991 

10.4348 

10.4787 

10.4898 

10.4737 

10.4518 

52 

235U 

Uncertainty 2) 
 [mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

Mass 1) 
 [mg] 
1.8008 

1.7929 

1.7990 

1.7937 

1.7933 

1.7958 

1.7691 

1.7938 

1.7960 

1.7981 

1.7962 

1.7992 

1.7951 

1.7962 

1.7968 

1.7902 

1.7684 

1.7939 

1.7965 

1.7967 

1.7943 

1.7978 

1.7957 

1.7969 

1.7962 

1.7965 

1.7956 

1.7926 

1.7945 

1.7996 

1.7685 

1.7908 

1.7950 

1.7931 

1.7711 

1.7896 

1.7921 

1.7988 

1.7676 

1.7927 

1.7949 

1.7921 

1.7669 

1.7945 

1.7658 

1.7891 

1.7966 

1.7985 

1.7957 

1.7920 

239Pu 

Uncertainty 2) 
 [mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
Unit # 

701 

702 

703 

704 

705 

706 

707 

708 

709 

710 

711 

712 

713 

714 

715 

716 

717 

718 

719 

720 

721 

722 

723 

724 

725 

726 

727 

728 

729 

730 

731 

732 

733 

734 

735 

736 

737 

738 

739 

740 

741 

742 

743 

744 

745 

746 

747 

748 

749 

750 

Organic 
substance 
CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

Mass 1) 
 [mg] 
43.098 

43.648 

43.802 

43.707 

43.753 

43.731 

43.809 

43.709 

43.743 

43.786 

43.774 

43.690 

43.778 

43.757 

43.696 

43.785 

43.610 

43.086 

43.627 

43.823 

43.798 

43.677 

43.755 

43.747 

43.743 

43.798 

43.703 

43.778 

43.641 

43.085 

43.653 

43.679 

43.850 

43.705 

43.772 

43.736 

43.007 

43.641 

43.762 

43.745 

43.731 

43.052 

43.636 

43.767 

43.750 

43.728 

43.693 

43.074 

43.612 

43.643 

238U 

Uncertainty 2) 
 [mg] 
0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

235U 

Uncertainty 2)  
[mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

239Pu 

Uncertainty 2) 
 [mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

Mass 1) 
 [mg] 
1.7694 

1.7919 

1.7982 

1.7943 

1.7962 

1.7953 

1.7985 

1.7944 

1.7958 

1.7976 

1.7971 

1.7936 

1.7972 

1.7964 

1.7939 

1.7975 

1.7904 

1.7689 

1.7911 

1.7991 

1.7981 

1.7931 

1.7963 

1.7960 

1.7958 

1.7981 

1.7942 

1.7972 

1.7916 

1.7688 

1.7921 

1.7932 

1.8002 

1.7943 

1.7970 

1.7955 

1.7656 

1.7916 

1.7966 

1.7959 

1.7953 

1.7674 

1.7914 

1.7968 

1.7961 

1.7952 

1.7938 

1.7684 

1.7904 

1.7917 

Mass 1) 
  [mg] 
10.3198 

10.4514 

10.4882 

10.4654 

10.4766 

10.4712 

10.4898 

10.4658 

10.4741 

10.4845 

10.4816 

10.4613 

10.4824 

10.4774 

10.4629 

10.4841 

10.4423 

10.3169 

10.4464 

10.4932 

10.4874 

10.4584 

10.4770 

10.4749 

10.4741 

10.4874 

10.4646 

10.4824 

10.4497 

10.3165 

10.4526 

10.4588 

10.4998 

10.4650 

10.4812 

10.4725 

10.2978 

10.4497 

10.4787 

10.4745 

10.4712 

10.3086 

10.4485 

10.4799 

10.4758 

10.4704 

10.4621 

10.3140 

10.4427 

10.4501 

53 

 
 
 
 
 
 
Unit # 

751 

752 

753 

754 

755 

756 

757 

758 

759 

760 

761 

762 

763 

764 

765 

766 

767 

768 

769 
7704) 

771 
7724) 

773 
7744) 
7754) 
7764) 

777 

778 

779 

780 

781 

782 

783 

784 

785 

786 

787 

788 

789 

790 

791 

792 

793 

794 

795 

796 

797 

798 

799 

800 

Organic 
substance 
CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CAB/DOP 

N/A 

Mass 1) 
 [mg] 
43.055 

43.620 

43.831 

43.788 

43.714 

43.740 

43.766 

43.731 

43.762 

43.709 

43.804 

43.759 

43.753 

43.785 

43.586 

43.817 

43.767 

43.721 

43.819 

N/A 

CAB/DOP 

43.639 

N/A 

N/A 

CAB/DOP 

43.677 

N/A 

N/A 

N/A 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

N/A 

N/A 

N/A 

43.698 

43.871 

43.752 

43.757 

43.715 

43.762 

43.880 

43.617 

43.009 

43.816 

43.586 

43.665 

43.864 

43.710 

43.738 

43.828 

43.650 

43.764 

43.100 

43.581 

43.805 

43.005 

43.615 

43.664 

238U 

Uncertainty 2) 
 [mg] 
0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

N/A 

0.023 

N/A 

0.024 

N/A 

N/A 

N/A 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.024 

0.023 

0.023 

0.023 

235U 

Uncertainty 2)  
[mg] 
0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

N/A 

0.0052 

N/A 

0.0052 

N/A 

N/A 

N/A 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

Mass 1) 
 [mg] 
1.7676 

1.7908 

1.7994 

1.7977 

1.7946 

1.7957 

1.7967 

1.7953 

1.7966 

1.7944 

1.7983 

1.7965 

1.7962 

1.7975 

1.7894 

1.7989 

1.7968 

1.7949 

1.7989 

N/A 

1.7916 

N/A 

1.7931 

N/A 

N/A 

N/A 

1.7940 

1.8011 

1.7962 

1.7964 

1.7947 

1.7966 

1.8014 

1.7906 

1.7657 

1.7988 

1.7894 

1.7926 

1.8008 

1.7945 

1.7956 

1.7993 

1.7920 

1.7967 

1.7694 

1.7891 

1.7984 

1.7655 

1.7906 

1.7926 

Mass 1) 
  [mg] 
10.3094 

10.4447 

10.4952 

10.4849 

10.4671 

10.4733 

10.4795 

10.4712 

10.4787 

10.4658 

10.4886 

10.4778 

10.4766 

10.4841 

10.4365 

10.4919 

10.4799 

10.4687 

10.4923 

N/A 

10.4493 

N/A 

10.4584 

N/A 

N/A 

N/A 

10.4634 

10.5047 

10.4762 

10.4774 

10.4675 

10.4787 

10.5068 

10.4439 

10.2982 

10.4915 

10.4365 

10.4555 

10.5031 

10.4663 

10.4729 

10.4944 

10.4518 

10.4791 

10.3202 

10.4352 

10.4890 

10.2974 

10.4435 

10.4551 

54 

239Pu 

Uncertainty 2)  
[mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

N/A 

0.0013 

N/A 

0.0013 

N/A 

N/A 

N/A 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
238U 

235U 

239Pu 

Unit # 

801 

802 

803 

804 

805 

806 

807 

808 

809 

810 

811 

812 

813 

814 

815 

816 

817 
8183) 

819 

820 

821 

822 

823 

824 

825 

826 

827 

828 

829 

830 

831 

832 

833 

834 

835 

836 

837 

838 

839 

840 

841 

842 

843 

844 

845 

846 

847 

848 

849 

850 

Organic 
substance 
CAB/DOP 

Mass 1)  
[mg] 
43.873 

Uncertainty 2) 
 [mg] 
0.024 

CAB/DOP 

43.783 

CAB/DOP 

43.714 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CAB/DOP 

CMC 

N/A 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

43.772 

43.850 

43.728 

43.702 

42.977 

43.651 

43.774 

43.764 

43.728 

43.669 

43.102 

43.546 

43.079 

43.620 

N/A 

43.035 

43.664 

43.781 

43.776 

43.612 

43.793 

43.040 

43.662 

43.696 

43.079 

43.539 

43.816 

42.993 

43.596 

43.064 

43.584 

43.035 

43.715 

43.722 

43.781 

43.709 

43.810 

43.840 

43.698 

43.693 

43.935 

43.741 

43.778 

43.662 

43.054 

43.714 

43.798 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

N/A 

0.023 

0.023 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.024 

0.023 

0.023 

0.024 

0.023 

0.023 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

Mass 1)   
[mg] 
10.5052 

10.4836 

10.4671 

10.4812 

10.4998 

10.4704 

10.4642 

10.2908 

10.4522 

10.4816 

10.4791 

10.4704 

10.4563 

10.3206 

10.4269 

10.3152 

10.4447 

N/A 

10.3045 

10.4551 

10.4832 

10.4820 

10.4427 

10.4861 

10.3057 

10.4547 

10.4629 

10.3152 

10.4253 

10.4915 

10.2945 

10.4389 

10.3115 

10.4361 

10.3045 

10.4675 

10.4692 

10.4832 

10.4658 

10.4903 

10.4973 

10.4634 

10.4621 

10.5201 

10.4737 

10.4824 

10.4547 

10.3090 

10.4671 

10.4874 

55 

Uncertainty 2)  
[mg] 
0.0052 

Mass 1)  
[mg] 
1.8011 

Uncertainty 2) 
 [mg] 
0.0013 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

N/A 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0051 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

1.7974 

1.7946 

1.7970 

1.8002 

1.7952 

1.7941 

1.7644 

1.7921 

1.7971 

1.7967 

1.7952 

1.7928 

1.7695 

1.7877 

1.7686 

1.7908 

N/A 

1.7667 

1.7926 

1.7974 

1.7972 

1.7904 

1.7979 

1.7669 

1.7925 

1.7939 

1.7686 

1.7874 

1.7988 

1.7650 

1.7898 

1.7679 

1.7893 

1.7667 

1.7947 

1.7950 

1.7974 

1.7944 

1.7986 

1.7998 

1.7940 

1.7938 

1.8037 

1.7957 

1.7972 

1.7925 

1.7675 

1.7946 

1.7981 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

N/A 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

 
 
 
 
 
 
 
 
 
Unit # 

851 

852 

853 

854 

855 

856 

857 

858 

859 

860 

861 

862 

863 

864 

865 

866 

867 

868 

869 

870 

871 

872 

873 

874 

875 

876 

877 

878 

879 

880 

881 

882 

883 

884 

885 

886 

887 

888 

889 

890 

891 

892 

893 

894 

895 

896 

897 

898 

899 

900 

Organic 
substance 
CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CAB/DOP 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

Mass 1) 
 [mg] 
43.733 

43.774 

43.766 

43.800 

43.791 

43.631 

43.861 

42.996 

43.615 

43.892 

43.679 

43.714 

43.911 

42.986 

43.736 

43.786 

43.731 

43.722 

43.005 

43.676 

43.709 

43.066 

43.603 

43.019 

43.684 

43.821 

43.845 

43.729 

43.683 

43.054 

43.657 

43.840 

43.729 

43.805 

43.667 

43.866 

43.612 

43.862 

43.805 

43.809 

43.824 

43.641 

43.791 

43.755 

43.055 

43.634 

43.057 

43.636 

43.123 

43.619 

238U 

Uncertainty 2)  
[mg] 
0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.023 

0.024 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

0.024 

0.024 

0.023 

0.023 

0.023 

0.023 

0.023 

0.023 

235U 

239Pu 

Uncertainty 2)  
[mg] 
0.0052 

Mass 1)  
[mg] 
1.7954 

Uncertainty 2) 
 [mg] 
0.0013 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0051 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

1.7971 

1.7967 

1.7982 

1.7978 

1.7912 

1.8006 

1.7652 

1.7906 

1.8019 

1.7932 

1.7946 

1.8027 

1.7647 

1.7955 

1.7976 

1.7953 

1.7950 

1.7655 

1.7930 

1.7944 

1.7680 

1.7901 

1.7661 

1.7934 

1.7990 

1.8000 

1.7952 

1.7933 

1.7675 

1.7923 

1.7998 

1.7952 

1.7984 

1.7927 

1.8009 

1.7904 

1.8007 

1.7984 

1.7985 

1.7992 

1.7916 

1.7978 

1.7963 

1.7676 

1.7913 

1.7676 

1.7914 

1.7703 

1.7907 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

Mass 1)  
 [mg] 
10.4716 

10.4816 

10.4795 

10.4878 

10.4857 

10.4472 

10.5023 

10.2954 

10.4435 

10.5097 

10.4588 

10.4671 

10.5143 

10.2929 

10.4725 

10.4845 

10.4712 

10.4692 

10.2974 

10.4580 

10.4658 

10.3119 

10.4406 

10.3007 

10.4601 

10.4927 

10.4985 

10.4708 

10.4596 

10.3090 

10.4534 

10.4973 

10.4708 

10.4890 

10.4559 

10.5035 

10.4427 

10.5027 

10.4890 

10.4898 

10.4936 

10.4497 

10.4857 

10.4770 

10.3094 

10.4481 

10.3098 

10.4485 

10.3256 

10.4443 

56 

 
 
 
 
 
Unit # 

901 

902 

903 

904 

905 

906 

907 

908 

909 

910 

911 

912 

Organic 
substance 
CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

CMC 

Mass 1) 
 [mg] 
43.866 

43.641 

43.848 

43.667 

43.057 

43.681 

43.060 

43.690 

43.842 

43.667 

43.759 

43.154 

238U 

Uncertainty 2) 
 [mg] 
0.024 

0.023 

0.024 

0.024 

0.023 

0.024 

0.023 

0.024 

0.024 

0.024 

0.024 

0.023 

Mass 1)  
[mg] 
10.5035 

10.4497 

10.4994 

10.4559 

10.3098 

10.4592 

10.3107 

10.4613 

10.4977 

10.4559 

10.4778 

10.3330 

235U 

Uncertainty 2)  
[mg] 
0.0052 

0.0052 

0.0052 

0.0052 

0.0051 

0.0052 

0.0051 

0.0052 

0.0052 

0.0052 

0.0052 

0.0052 

239Pu 

Uncertainty 2) 
 [mg] 
0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

0.0013 

Mass 1) 
 [mg] 
1.8009 

1.7916 

1.8001 

1.7927 

1.7676 

1.7933 

1.7678 

1.7936 

1.7999 

1.7927 

1.7965 

1.7716 

1) The certified values are traceable to the values on the respective metal certificates (EC NRM 101, NBL PO 
CRM 116-A and CETAMA MP2). The reference date for the mass of 238U, 235U and 239Pu per unit is November 
1, 2019. 

2) The reference material was produced in compliance with ISO/IEC 17034:2016 and certified in accordance with 
ISO Guide 35:2017. The uncertainty of the certified value is the expanded uncertainty with a coverage factor k = 
2 corresponding to a level of confidence of about 95 % estimated in accordance with ISO/IEC Guide 98-3:2008, 
Guide to the Expression of Uncertainty in Measurement (GUM:1995).  

3) One unit excluded from the certification process based on barcode failure. 

4) 6 units excluded from the certification process due to splashing before drying. 

5) 9 units reserved for experimental purposes. 

The atomic masses of radionuclides were obtained from Wang et al. (The AME 2016 atomic mass evaluation 
(II). Tables, Graphs and References, Chinese Physics C, Vol. 41, No. 3, 2017). The half-lives of radionuclides 
were obtained from DDEP-BIPM (Table of radionuclides) and R. Wellum et al. (A new evaluation of the half-life 
of 241Pu, J. Anal. At. Spectrom., 24, 801-807, 2009). 

57 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Annex 2 The certificate of EC NRM 101 uranium metal 

58 

 
 
 
 
 
 
 
 
 
Annex 3 The certificate of isotopic composition of EC NRM 101 

59 

 
 
 
 
 
Annex 4 The certificate of NBL PO CRM 116-A uranium metal 

60 

 
 
61 

 
62 

 
 
 
 
Annex 5 The certificate of CETAMA MP2 plutonium metal 

63 

 
                   
64 

 
`

65 

 
66 

 
                                    
 
 
Annex 6 The certificate of plutonium isotope abundances of CETAMA MP2 

67 

 
 
 
 
68 

 
 
 
 
 
 
Annex 7 The certificate of uranium amount content and isotope abundances of CETAMA MP2 

69 

 
 
70 

 
 
71 

 
 
Annex 8 The certificate of IRMM-046c 

72 

 
  
73 

 
 
 
 
74 

 
 
Annex 9 IRMM-1027v mother solution verification 

Figure 14 Verification results of the IRMM-1027v mother solution by IDMS on the a)  235U, b) 238U and c) 239Pu amount contents. 
Red dashed lines show the relative expanded uncertainty of the gravimetric value with a coverage factor k = 2 with the exception of 
235U amount content and mass fraction values, which have a coverage factor k = 2.3 (dfeff = 9). Blue lines show the mean ID-TIMS 
values and the blue shaded area represents their expanded uncertainties with a coverage factor k = 2. 

75 

 
 
 
 
 
 
Annex 10 Results of the homogeneity assessment for IRMM-1027v 

Figure 15 The amount content of 235U from homogeneity study for the 33 replicate measurements (18 selected units, 3 replicates 
each) are shown as a function of the analytical sequence. No significant trend at the 95% CI was observed. 

Figure 16 The amount content of 235U from homogeneity study for the 33 replicate measurements (11 selected units, 3 replicates each) are 
shown as a function of the filling sequence. The x positions are slightly ‘dodged’ to make overlapping data visible. Significant trend at the 
95% CI was observed (p<0.05). 

76 

y1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xy1.7611e-052.406e-10xp = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.25p = 0.251.758e-051.759e-051.760e-051.761e-051.762e-051.763e-050102030analytical sequence235Uamount content (101molg solution)y1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xy1.7608e-051.615e-11xp = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.026p = 0.0261.758e-051.759e-051.760e-051.761e-051.762e-051.763e-050100200300400500600700800900Filling sequence235Uamount content (101molg solution) 
 
 
 
Figure 17 The amount content of 238U from homogeneity study for the 33 replicate measurements (11 selected units, 3 replicates each) are 
shown as a function of the analytical sequence. No significant trend at the 95% CI was observed. 

Figure 18 The amount content of 238U from homogeneity study for the 33 replicate measurements (11 selected units, 3 replicates each) are 
shown as a function of the filling sequence. The positions are slightly ‘dodged’ to make overlapping data visible. No significant trend at the 
95% CI was observed. 

77 

y7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xy7.2614e-053.549e-10xp = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.73p = 0.737.250e-057.255e-057.260e-057.265e-057.270e-057.275e-050102030analytical sequence238Uamount content (101molg solution)y7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xy7.2592e-056.159e-11xp = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.091p = 0.0917.250e-057.255e-057.260e-057.265e-057.270e-057.275e-050100200300400500600700800900Filling sequence238Uamount content (101molg solution) 
 
 
 
Figure 19 The normalised amount content of 239Pu from homogeneity study for the 33 replicate measurements (11 selected units, 3 
replicates each) are shown as a function of the analytical sequence. No significant trend at the 95% CI was observed. 

Figure 20 The normalised amount content of 239Pu from homogeneity study for the 33 replicate measurements (11 selected units, 3 
replicates each) are shown as a function of the filling sequence. The positions are slightly ‘dodged’ to make overlapping data visible. No 
significant trend at the 95% CI was observed. 

78 

y0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06xy0.999962.697e-06x p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.65 p =0.650.99961.00001.00040102030analytical sequence239Punormalised amount contenty0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07xy0.999833.896e-07x p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.059 p =0.0590.99961.00001.00040100200300400500600700800900Filling sequence239Punormalised amount content 
 
 
 
 
 
 
 
Figure 21 Tukey’s boxplot representation of day-to-day differences for a)  235U b)  238U and c)  239Pu amount contents (the latter 
before normalisation). The boxes represent the interquartile range (IQR) between the first and third quartile, the whiskers represent 
either the extremes or the ‘fences’ (1.5*IQR) and the individual dots represent outliers.  

79 

1.758e-051.759e-051.760e-051.761e-051.762e-051.763e-05123day235U(mol/g)a)7.250e-057.255e-057.260e-057.265e-057.270e-057.275e-05123day238U(mol/g)b)2.965e-062.966e-062.967e-062.968e-062.969e-06123day239Pu(mol/g)c) 
 
 
 
 
Annex 11 The weighing certificate of the aliquots of dispensed solution of IRMM-1027v per unit before drying 

80 

 
 
81 

 
82 

 
83 

 
84 

 
85 

 
86 

 
87 

 
88 

 
89 

 
90 

 
91 

 
92 

 
 
Annex 12 The weighing certificate for the preparation of the mother solution of IRMM-1027v  

93 

 
 
94 

 
 
 
Annex 13 Uncertainty budget for the uranium gravimetric mixture of IRMM-1027v 

95 

 
 
 
96 

 
 
97 

 
 
98 

 
 
99 

 
 
100 

 
 
101 

 
 
102 

 
 
103 

 
 
104 

 
 
105 

 
 
106 

 
 
107 

 
 
108 

 
 
109 

 
 
110 

 
 
111 

 
 
112 

 
 
113 

 
 
114 

 
 
115 

 
 
 
 
                                 
Annex 14 Uncertainty budget for the plutonium gravimetric mixture of IRMM-1027v 

116 

 
 
117 

 
 
118 

 
 
119 

 
 
120 

 
 
121 

 
 
122 

 
 
123 

 
 
124 

 
 
125 

 
 
126 

 
 
127 

 
 
128 

 
 
129 

 
 
130 

 
 
131 

 
 
                
 
 
Annex 15 The weighing certificate of the blend mixtures for the confirmation measurements of 235U, 238U and 239Pu 
amount content by ID-TIMS using IRMM-046c.  

132 

 
 
 
133 

 
 
 
 
 
Annex 16 The internal test reports (#4589 and #4662) for the selected units of IRMM-1027v. (Typo: the date of 
the first set of IDMS samples was 20/02/2020 and not 02/02/2020). 

134 

 
 
135 

 
 
136 

 
 
137 

 
 
 
138 

 
 
139 

 
 
140 

 
 
141 

 
 
142 

 
 
143 

 
 
144 

 
 
 
 
GETTING IN TOUCH WITH THE EU 

In person 
All over the European Union there are hundreds of Europe Direct information centres. You can find the address of the centre 
nearest you at: https://europa.eu/european-union/contact_en 

On the phone or by email 
Europe Direct is a service that answers your questions about the European Union. You can contact this service: 
- by freephone: 00 800 6 7 8 9 10 11 (certain operators may charge for these calls), 
- at the following standard number: +32 22999696, or 
- by electronic mail via: https://europa.eu/european-union/contact_en 

FINDING INFORMATION ABOUT THE EU 

Online 
Information about the European Union in all the official languages of the EU is available on the Europa website at: 
https://europa.eu/european-union/index_en 

EU publications 
You can download or order free and priced EU publications from EU Bookshop at: https://publications.europa.eu/en/publications. 
Multiple copies of free publications may be obtained by contacting Europe Direct or your local information centre (see 
https://europa.eu/european-union/contact_en). 

 
 
 
 
 
 
K
J
-
N
A
-
3
0
7
5
9
-
E
N
-
N

146 

doi:10.2760/59260 

ISBN 978-92-76-40041-7