- Y77) -
                                                                                                                                                                                    STUK-YTO-TR 99
                                                                                                                                                                                     Detection and analysis of
                                                                                                                                                                                      radioactive particles using
                                                                                                                                                                                       autoradiography
                                                                                                                                                                                      Report on task FIN A845 on the Finnish
                                                                                                                                                                                       support programme to IAEA safeguards
                                                                                                                                                                                      R. Pöllänen, A. Kansanaho, H. Toivonen
                                                                                                                                                                                       FEBRUARY 1996
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       :                                                               -''':•''''•;'. • •"'-". • ','.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          -V ^;                                                                       •''.-•••'.•.•. ., ..--:,•.-•
                                                                                                                                                                                                                                                   ;•*• •':•.'
                                                                                                                                                                                                                                                                                                                                                                                                        1
                                                                                                                                                                                                                                                                                          ••'":' .*•••.•-•„' •' .* •'"••••:."•.'.'' •• -- ",;-, :•<'.>
                                                                                                                                                                                                                                                                                           .• - - JV _• • -,• ,-.'-,• -.'-<• -i '"i .••.--•- * i .i
                                                                                                                                                                                     SÄTEILYTURVAKESKUS
                                                                                                                                                                                     Strälsäkerhetscentralen
                                                                                                                                                                                     Finnish Centre for Radiation and
                                                                                                                                                                                      Nuclear Safety
                                                                                                                        VOL 2 7 MS 1 5
             STUK-YTO-TR 99
             FEBRUARY 1996
             Detection and analysis of
             radioactive particles using
             autoradiography
             Report on task FIN A845 on the Finnish
             support programme to IAEA safeguards
             R. Pöllänen, A. Kansanaho, H. Toivonen
             Finnish Centre for Radiation and Nuclear Safety
             Aerosol Laboratory
             The study was supervised by
             M. Tarvainen
             FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY
             P.O.BOX 14, FIN-00881 HELSINKI, FINLAND
             Tel. +358-0-759881
             Fax +358-0-75988433
           ISBN 951-712-099-0
           ISSN 0785-9325
           Oy Edita Ab
           Helsinki 1996
                                                           FINNISH CENTRE FOR RADIATION
            STUK-YTO-TR 99 AND NUCLEAR SAFETY
            PÖLLÄNEN, Roy, KANSANAHO, Ahti, TOIVONEN, Harri (Finnish Centre for Radiation and
            Nuclear Safety). Detection and analysis of radioactive particles using autoradiography. Report on
            task FIN A845 on the Finnish support programme to IAEA safeguards. STUK-YTO-TR 99.
            Helsinki 1996. 34 pp + Apps. 2 pp.
            ISBN 951-712-099-0
            ISSN 0785-9325
            Keywords: environmental monitoring, autoradiography, radioactive particles, safeguards
            ABSTRACT
            Autoradiography was used to study radioactive particles that may be released from the nuclear fuel
            cycle. Autoradiography suits for pre-screening of the samples. Radioactive particles can be located
            accurately and detached from the sample for subsequent analyses. A digital scanner and tailored
            software allow to estimate the activity of the particles by a factor of two to three. High-energy beta
            emitters as well as pure beta emitters can be identified. A particle with activity of 0.1 Bq can be
                                                5
            detected in five days of exposure. More than 10  disintegrations are needed to detect a black spot on
            the autoradiography film. Total activity of beta active nuclides can be evaluated if the number of
                                     6
            disintegrations is smaller than 10 . The diameter of the black spot is then below 1 mm. The edge of
            the black spot receives a beta dose of approximately 10 mGy. Particular emphasis was placed on
            method development from the point of view of in-field applications.