Noble gas radionuclides in RBMK-1500-type reactor.

The presence of noble gas and other short-lived radionuclides in air borne effluents from RBMK-1500-type reactor has been investigated using experimental and theoretical instrumentation for detection purposes. Activity concentrations of (85m)Kr, (87)Kr, (88)Kr, (135m)Xe, (135)Xe, (133)Xe and (41)Ar were measured in air emissions from Ignalina NPP using a special method and special equipment. Theoretical detection of reactor-borne radionuclides and investigation of their behaviour in a nuclear fuel during operation of nuclear reactor was performed using an analytical model based on reactor physics.

Assessment of the environmental contamination with long-lived radionuclides around an operating RBMK reactor station.

The presence of man-made gamma emitting radionuclides in the region within 32km radius of the Ignalina NPP/Lithuania has been investigated during the period 2001-2004, prior to the closure of the first of the two operating RBMK 1500-type reactors. Gamma spectrometric measurements of various terrestrial and aquatic plants as well as of soil samples showed moderate environmental contamination with the fission product (137)Cs and with the neutron activation products (60)Co and (54)Mn. Traces of the activation products (65)Zn and (110m)Ag were found in the nearest vicinity of the NPP.

Optimisation of X-ray examinations in Lithuania: start of implementation in mammography.

Optimisation of medical X-ray examinations is very important for the enhancement of the reliability of the examination and for the reduction of the radiation dose to patients. Results of investigations of doses to patients during mammography using thermoluminescence dosemeters at different hospitals are presented together with a brief overview of the situation for mammography in Lithuania. It is shown that the entrance surface air kerma varies in a broad range and differed from hospital to hospital.