CIPM MRA COMPARISON REPORTS
KEY COMPARISON
CCRI(II)-K2.Tc-99
Activity of the radionuclide 99Tc per unit mass of aqueous solution
Published on 19/01/2026 - © 2026 A.K. Pearce et al
Citation A.K. Pearce et al 2026 CIPM MRA Comparison reports 06001
Authors
A. K. Pearce National Physical Laboratory (NPL) UK 
T. Altzitzoglou European Commission, Joint Research Centre (JRC) Belgium
A. Antohe Institutul National de Cercetare-Dezvoltare pentru Fizică şi Inginerie Nucleară- “Horia Hulubei” (IFIN-HH) Romania
P. Arenillas Comisión Nacional de Energía Atómica (CNEA) Argentina
E. Bakhshandeiar National Physical Laboratory (NPL) UK
D. Bergeron National Institute of Standards and Technology (NIST) USA
C. Bobin Laboratoire National Henri Becquerel (LNE-LNHB) France
M. Capogni Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA) Italy
P. Cassette Laboratoire National Henri Becquerel (LNE-LNHB) France
R. Collé National Institute of Standards and Technology (NIST) USA
S. Collins National Physical Laboratory (NPL) UK
S. Courte Bureau International des Poids et Mesures (BIPM)
M. L. Cozzella Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA) Italy
T. Dziel National Centre for Nuclear Research Radioisotope Centre (POLATOM) Poland
A. Fazio Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA) Italy
R. Fitzgerald National Institute of Standards and Technology (NIST) USA
R. Galea National Research Council (NRC) Canada
E. Garcia-Toraño Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) Spain
M.-R. Ioan Institutul National de Cercetare-Dezvoltare pentru Fizică şi Inginerie Nucleară- “Horia Hulubei” (IFIN-HH) Romania
L. Johansson National Physical Laboratory (NPL) UK
L. Joseph Bhabha Atomic Research Center (BARC) India
L. King National Institute of Standards and Technology (NIST) USA
K. Kossert Physikalisch-Technische Bundesanstalt (PTB) Germany
M. Krivosik Laboratoire National Henri Becquerel (LNE-LNHB) France
D. B. Kulkarni Bhabha Atomic Research Center (BARC) India
L. Laureano-Pérez National Institute of Standards and Technology (NIST) USA
J. Lubbe National Metrology Institute of South (NMISA) South Africa
K. Moore National Research Council (NRC) Canada
X. Mougeot Laboratoire National Henri Becquerel (LNE-LNHB) France
O. Nähle Physikalisch-Technische Bundesanstalt (PTB) Germany
L. Pibida National Institute of Standards and Technology (NIST) USA
G. Ratel Bureau International des Poids et Mesures (BIPM)
A. Ravindra Bhabha Atomic Research Center (BARC) India
D. Rodrígues Comisión Nacional de Energía Atómica (CNEA) Argentina
L. Rodríguez Barquero Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) Spain
M. Roteta Comisión Nacional de Energía Atómica (CNEA) Argentina
M. Sahagia Institutul National de Cercetare-Dezvoltare pentru Fizică şi Inginerie Nucleară- “Horia Hulubei” (IFIN-HH) Romania
Y. Sato National Metrology Institute of Japan (NMIJ) Japan
S. V. Sepman D. I. Mendeleev Institute for Metrology (VNIIM) Russia
I. A. Sokolova D. I. Mendeleev Institute for Metrology (VNIIM) Russia
A. Stroak National Research Council (NRC) Canada
M. van Staden National Metrology Institute of South Africa (NMISA) South Africa
F. van Wyngaardt National Metrology Institute of South Africa (NMISA) South Africa
A. Yunoki National Metrology Institute of Japan (NMIJ) Japan
A. V. Zanesky D. I. Mendeleev Institute for Metrology (VNIIM) Russia
B. Zimmerman National Institute of Standards and Technology (NIST) USA
Abstract
This is the final report for the CCRI(II)-K2.Tc-99 key comparison of the activity of the radionuclide 99Tc per unit mass of aqueous solution which was organised in 2012 by the National Physical Laboratory of the United Kingdom. The Key Comparison Reference Value (KCRV) of 56.45 kBq g-1 with a combined standard uncertainty of 0.13 kBq g-1 was determined from the power-moderated mean of the results of 13 laboratories, with results from a further three laboratories being rejected by the accepted statistical criteria.
Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.
The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).