On 22 to 23 November 2021 the 18th meeting of TC 1.9 "Ionizing Radiation and Radioactivity" was held online, at which the following persons took part: representatives of 10 COOMET member countries (Azerbaijan, Armenia, Belarus, Bosnia and Herzegovina, Georgia, Moldova, Russia, Slovakia, Uzbekistan, Ukraine), Chair of the Joint Committee for Measurement Standards A. Chunovkina, BIPM representatives: Executive Secretary of the Consultative Committee for Ionizing Radiation (CCRI) V. Gressier, C. Kessler, D. Burns and R. Coulon, as well as the Chair of the Dosimetry Section CCRI(I) M. McEwen (NRC, Canada), Head of COOMET Secretariat N.Liakhova.

The following issues were discussed during the meeting:

• resolutions of the 31^st COOMET Committee meeting;
• resolutions of the Joint Committee for Measurement Standards, adopted in 2021;
• information about the activities of EURAMET CCRI, TС-RI;
• TC 1.9 activities over the period since the last meeting;
• information about the activities of NMIs of TC 1.9 member countries in the field of measuring ionizing radiation;
• implementation of the current projects, carried out within TC 1.9 and proposal on new projects;
• update of the list of COOMET technical experts on CMC review and prospects for implementation of the CIPM MRA.

Main adopted decision:

1. to continue work on the comparisons within TC 1.9, provided for in the COOMET Development Program, inter alia:  

• following the CCRI review to publish a report on comparisons COOMET.RI(I)-S3 "Comparisons of national standards of air kerma for x-radiation qualities used for radiation protection and diagnostic radiology" (project 641/BY-а/14, pilot – BelGIM, Belarus) and to complete the COOMET project in accordance with the established procedure;
• to intensify work on comparisons COOMET.RI(II)-S3 «Comparisons of national standards on measuring radioactivity in point sources» (project 833/RU-а/20, pilot – VNIIM, Russia);
• to agree on the technical protocol and register the comparisons on measuring the activity of  a radioactive solution of Barium-133 (timeframe for implementation - 2022);

2. to complete the preparation of the calibration procedure for gamma spectrometers in 2021 (project 600/RU-а/13, pilot– VNIIM, Russia);

3. to collect information about the needs of COOMET NMIs to conduct new comparisons in dosimetry on the absorbed dose in water for radiation of cobalt-60 and comparisons on kerma in air  and related values of X-ray radiation, as well as information about the possibility of piloting such comparisons and the need to hold preliminary training seminars.

The next TC meeting is scheduled for autumn 2022 (the venue and format of the event will be decided in view of the situation with the Covid-19 pandemic).