2011 YÜksek lisans tez özetleri

Determination of Natural Radiation Sources and Assessment of Gamma Dose Rates In Kırıkkale (Turkey)

The aim of this study is to establish and radiologically investigate the background radiation levels of the city of Kırıkkale which contains active faults in its boundaries. For this goal, to represent the whole Kırıkkale, 84 soil and 85 drinking water samples have been collected and gamma radiation doses have been measured at 170 points. The coordinates of the sample points which are chosen to map the radiation levels of the region was found and saved by using a GPS instrument.

Soil samples were analyzed by using a Canberra, GX5020 model gamma spectrometer which had HPGe (High purity Germanium) detector. By analyzing the samples, the activity concentration of natural isotopes ²²⁶Ra, ²³²Th, ⁴⁰K and fission product ¹³⁷Cs has been found.

In this study, water samples were prepared for analysis using EPA 900.0 method and SM 7110 C co-precipitation method. To find gross alpha and gross beta activities in the drinking water samples, a Berthold, LB770 model, 10 channel, low level gas flowing, proportional counter was used.

To establish gamma dose rate levels in open field, a Ludlum 2242-2 model mobile digital instrument with a 44-10 model, NaI(Tl) gamma scintillation detector was used. Gamma does rates were measured for one minute intervals at 1 meter above ground around human gonad level and saved in µSv/h units.

To determine indoor radon activity concentrations, 300 CR-39 plastic passive radon track detectors were placed at 150 designated houses in the region. This study was done at both summer and winter seasons to observe seasonal changes. Detectors were left for 80 days in the houses. At the end of this time, radon detectors were collected and processed with chemical etching to make alpha tracks on them more distinct. After the chemical etching process, the radon activity concentrations were determined when the detectors were analysized by an automatic radon track reading instrument which includes a computerized advanced microscope and software.

Moreover, the yearly effective doses and radiological risks were calculated for the people living in the region.

In the last part, the results of this study were discussed and compared with other results from Turkey and foreign countries.

  

KÜÇÜK Levent
Danışman : Doç. Dr. Yeşim ÖKTEM

Anabilim Dalı : Fizik

Programı : Nükleer Fizik

Mezuniyet Yılı : 2011

Tez Savunma Jürisi : Doç. Dr. Yeşim ÖKTEM

Prof Dr. Baki AKKUŞ

Prof. Dr. Metin ARIK

Yrd. Doç. Dr. Lidya SUSAM

Yrd. Doç. Dr. Ela GANİOĞLU