Czechoslovak intercomparison of neutron dosimetry methods for accidental exposures

Teams from six research laboratories compared their systems for assessing fluences and doses in the first series of Czechoslovak intercomparison measurements. Neutron and gamma-ray dosimetry systems for both accidental and chronic exposures were used. The experiments were carried out in the mixed radiation fields of: (i) the NA-2 neutron generator T(d,n)He; (ii) the WWR-S reactor; (iii) the IBR 30 reactor. The neutron generator was operated bare, under different conditions. (The neutron fluences were in the range of 8x1012m-2 to 6x1013m-2.) With the WWR-S reactor the thermal column was removed and irradiations were carried out in the area vacated. These were at relatively low powers: the neutron fluences were in the range of 5x1012 to 2x1014m-2 for neutron energies above 100keV. The pulsed IBR 30 reactor was operated bare (the neutron fluences were in the range of 2x1013 to 2x1015m-2 for neutron energies above 100keV). The teams made measurements both in free air and on phantoms (under the same irradiation conditions) using the following dose meters and detection systems: (1) Neutron detection methods: (a) 24Na induced phantom activity; (b) 32P induced activity in the hair and nails; (c) a set of activation detectors 23Na (n,gamma), 27Al (n,p), 27Al (n,alpha), 32S (n,p), 56Fe (n,p), 63Cu (n,2n), 64Zn (n,p), 115In (n,n'); (d) solid state track detectors (Usub(enr), Usub(nat)+Th, Th, all with polyester MELINEX or glass). (2) Gamma detection methods: (a) thermoluminescent dose meters (Al2O3, 7LiF, Al-P glass); (b) photoluminescent glass Yokota; (c) Fricke dose meter. (author)