Irradiation of Population in the SurroundingArea of Nuclear Power Plant Temelin

摘要

In monitoring the impact of nuclear facilities operation on ecosystem, it is necessary toconsider, what part of biota irradiation can be caused by an artificial source. For the estimation of aneffective dose from natural sources were used measurements of dosimetric and gamma spectrometriccharacteristics of photon fields, (performed in the area of NPP Temelin since year 2000) and datafrom the Czech Republic radiometric chart, including the results from radon volume activitymeasurements in dwellings. For gamma spectrometric measurements in situ were selected twomethodologies and for measurement were used corresponding types of equipment (Tesla NB3201 andspectrometer NaI(Tl) 3"x3") at selected locations within the monitored area: i) determination of airkerma rate (through direct measurement and by calculationfrom spectrometric data); ii) measurementof photon spectra by an scintillating spectrometer. For a dose assessment from artificial sourcesresulting from past or present operation of NPP Temelin, were used records from all so far performedlaboratory and field measurements of NPP releases, food baskets and also results of a 6 yearecosystem monitoring in the surrounding area of NPP Temelin. The ecosystem monitoring is based onstudying the contamination of the following hioindicators: forest humus, Pine bark, Schreber's Moss,the Bay Bolete (mushroom) and forest berries. Each year 220 samples are collected and mass activity(Bq/kg) for eventual contaminants is determined using laboratory gamma spectroscopy. Formeasurements is used a coaxial HPGe detector, with samples in the geometry of "Marinelli"container. For evaluation of the laboratory results obtained is used trend analysis. The above describedmonitoring has been performed from the year 2000 until now (the year 2000 is pre-operational). In allmeasured laboratory spectra, of all analyzed samples, were not identified any non-naturalradionuclides, with the exception of ~(137)Cs, for which maesured activities correspond, within allowedmeasurement error, to the conditions before the start of NPP Temelin operation.