Primerjava radioaktivnosti v okolici Žirovskega vrha s Krškim in Ljubljano : diplomsko delo

Benedik, Vlasta (author), Zupančič, Nina (mentor), Vokal, Barbara (co-mentor)

Ljudje so povsod izpostavljeni naravnemu in/ali antropogenemu ionizirajočemu sevanju. V Sloveniji z monitoringom radioaktivnosti merijo koncentracije radionuklidov v življenjskem okolju. Iz enotne relacijske baze podatkov o radioaktivnosti v okolju sem pridobila podatke o vsebnosti radionuklidov U-238, Ra-226 in Pb-210 v vodi in sedimentu, od leta 1984 do leta 2011, v okolici Rudnika urana Žirovski vrh, Nuklearne elektrarne Krško ter Ljubljane. Vsebnosti vseh izbranih radionuklidov so najvišje na področju Rudnika urana Žirovski vrh, kjer dosegajo povprečne specifične aktivnosti do 130 Bq/kg v sedimentih in do 145 Bq/m3 v vodi. Vsebnosti na tem področju so nekajkrat višje od področja Nuklearne elektrarne Krško in Ljubljane, kjer so v sedimentih do 47 Bq/kg in v vodi do 7 Bq/m3. Zakonsko dovoljene vsebnosti naravnih radionuklidov v vodi so za izotop U-238 3000 Bq/m3, Ra-226 480 Bq/m3 in Pb-210 190 Bq/m3. Na vseh treh področjih mejne vrednosti niso bile nikoli presežene. Sedimenti ne predstavljajo večjega vira sevanja za okoliške prebivalce. Analiza variance je pokazala, da so koncentracije radionuklidov na različnih lokacijah, predvsem na področju Žirovskega vrha, statistično značilno različne, kar je posledica različnega izluževanja radionuklidov in geološke sestave tal na posameznih lokacijah. V okolici Žirovskega vrha so vsebnosti povišane zaradi rudarjenja in predelave rude. Časovno se vsebnosti radionuklidov najizraziteje spreminjajo predvsem na področju rudnika urana v obeh vzorčnih medijih. Vsebnosti so bile najvišje v času obratovanja rudnika od leta 1985 do leta 1990, ko so dosegle tudi do 500 Bq/kg. Nekaj let po zaprtju rudnika se vrednosti niso bistveno zmanjšale. Po izvedenih sanacijskih delih na odlagališčih hidrometalurške jalovine Boršt in jamske jalovine Jazbec so se vsebnosti stabilizirale in so nižje kot v času obratovanja rudnika (50 Bq/kg). Na področju NEK in LJ nisem opazila spreminjanja vsebnosti s časom.

• Language: Slovenian
• Keywords: radioaktivnost, monitoring, radionuklidi, vsebnost, analiza variance
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Place of publishing: Ljubljana
• Publisher: [V. Benedik]
• Year: 2015
• Number of pages: VIII, 80 f., pril.
• PID: 20.500.12556/RUL-72310
• UDC: 55
• COBISS.SI-ID: 1204062
• Publication date in RUL: 11.09.2015

Secondary language

• Language: English
• Title: comparison of radioactivity in the Žirovski vrh area with Krško and Ljubljana

Abstract

Humans are exposed to natural and/or anthropogene radiation. In Slovenia the concentration of radionuclides in the environment is monitored. From the relational database containing data about radioacitvity in the environment I acquired the 1984 to 2011 contents of radionuclides U-238, Ra-226 and Pb-210 in the water and sediment, for the areas surrounding the Žirovski vrh Uranium Mine, the Krško Nuclear Power Plant and the city of Ljubljana. The contents of the chosen radionuclides are the highest around the mine, where the average contents are within reach up to 130 Bq/kg in sediments and up to 145 Bq/m3 in the water. The contents around the mine are a few times higher than around the generating station and Ljubljana area, where the contents in sediment are up to 47 Bq/kg and 7 Bq/m3 in the water. The legally allowed contents of natural radionuclides in the water are 3000 Bq/m3 for isotope U-238, 480 Bq/m3 for Ra-226 and 190 Bq/m3 for Pb-210. These contents were never exceeded. Sediments do not represent a major source of radiation for the population. The variation analysis showed that the concentration of radionuclides on different locations, especially around the mine, are statistically typically various. This is the result of different lixiviating of radionuclides and the geological soil structure. Around the mine the contents are increased as a consequence of mining and ore processing. Chronologically the content of radionuclides vary most distinctively around the mine in both water and sediment. The contents were the highest during the operation of the mine from 1986 to 1990, when they reached up to 500 Bq/kg. A few years after the mine was closed the values did not change significantly. After remediation of the dump of hydrometallurgic barren soil Boršt and of the mine barren soil Jazbec, the contents were stabilized and are today lower than at the time when the mine worked (50 Bq/kg). No changes in radiation were observed around the Krško Nuclear Power Plant and in the Ljubljana area during the entire analyzed period.

• Keywords: radioactivity, monitoring, radionuclides, content, analysis of variance