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Scientific Research of the Union of Scientists in Bulgaria - Plovdiv, series G. Medicine, Pharmacy and Dental medicine, Vol. XVII, ISSN 1311-9427, International Conference of Young Scientists, 11 - 13 June 2015, Plovdiv
ACTIVITIES IN RADIOACTIVE WASTE OF KOSOVO Besire Cena1*, kostandin Dollani
Abstract
Important event after the inventory of radioactive waste in Kosovo, their location and the number of radioactive sources, is the determination of the type of radioisotope and their activities.
Activity was conducted entirely in difficult terrain and was taken due to the absence in most cases of resource certificates or any other document with the necessary information that will enable the identification of radioactive sources and their activity.
In this way the activity was undertaken which aimed to identify key terms that constituted the type of radioisotope sources inventoried, as well as their initial activities planned, which will more or less coincide with the time of installation of these radioactive sources in equipment different measurement.
Key words: radioisotope, activity, radioactive waste .
Introduction
In this study were presented the results of determining the activity of various radioactive sources that were located in different institutions, was used relation that exists between a radioactive source and equivalent dose rate that creates the radioactive source at a certain distance. Relation between the magnificence given by the following expression (Dollani, 2007):
H' = r a / r2 (1)
where H' is the dose equivalent rate in mSv / h , r is the specific gamma constant of radioactive sources mSv.m2/MBq.h, a radioactive source activity and r is distance measuring device from the radioactive source. Starting from the above link can be drawn activity of a radioactive source a , a (power) function of dose equivalent rate H' and r the distance measuring apparatus of the radioactive source in the study.
a = H'. r2/.r (2)
For this purpose in each case was carried out by our measurement of dose equivalent rate of a given radioactive source in a fixed distance, which for ease of calculation is taken equal to 1 meter.
Materials and Methods
Regarding the specific gamma constant values (r), they are taken from references (Unger
1 * Corresponding: E-Mail: [email protected]
and Trubey, 1982), where besides the specific gamma constant for various radioactive sources was given the radioisotope half-life period and the respective energy values of gamma radiation issued by this radioisotope. As measuring devices is used an instrument for measuring of dose equivalent rate, which besides value of equivalent dose rate have identified the type of radioisotope. This measuring device is: "Exploranium GR-130", which is owned by the Protection Service Radiation Institute of Occupational Medicine, Obilic (Canberra, 2001). Based on these measurements is powered Table 1, in which the key data are presented for each source of radiation, including the type of radioisotope, half-life period, specific gamma constant and activity of radiation sources .
Table 1. Halving the period values, specific gamma constant, dose rate and activity for radioactive sources in the form of waste.
Radioactive source, Period of Specific gamma Distance, the
location halving constant power of dose Activity
Object A
Source 1 1m,1.06 ^Sv/h 0.4x103 MBq
Cs-137 30.17 year 1.017E-4 2m,0.13 ^Sv/h 0.2x103 MBq
Source 2 1m,2.78 ^Sv/h 1.19x103 MBq
Cs-137 30.17 year 1.017E-4 2m,0.15 ^Sv/h 0.25x103 MBq
Source 3
Cs-137 30.17 year 1.017E-4 1m,0.10 ^Sv/h 0.04x103 MBq
Source 4 1m,0.19 ^Sv/h 0.08x103 MBq
Cs-137 30.17 year 1.017E-4
Source 5 1m,0.23 ^Sv/h 0.09x103 MBq
Cs-137 30.17 year 1.017E-4
Object B
Source 1 Co-60 5.3 year 3,697E-4 1.5m,0.08 ^ Sv/h 0.01x103MBq
Source 2 Co-60 5.3 year 3,697E-4 1.5m ,0.09 ^ Sv/h 0.02x103MBq
Source 3 Co-60 5.3 year 3,697E-4 1.5m ,4.13 ^ Sv/h 1.01x103MBq
Figure 1. Display gamma spectrometric two Co-60 sources. Discussion and Conclusion
Using the device "Exploranium GR-130" was performed gamma spectrometry analysis of radioactive sources, which has resulted in the building of their gamma spectra. Figure 1 shows the
spectrum of a source of cobalt-60 Co, which emits gamma radiation of the two groups energies: The first energy interval 1119-1208 keV and the second in the interval 1285-1370 keV. The first peak corresponds to the energy of 1170 keV gamma radiation, while the second peak belongs energy of 1330 keV gamma radiation. Energies corresponding to this decay scheme fits precisely the source of Co-60, which is part of the library industrial GR-130 device. Theoretically it is known that the Co-60 radioisotope has a decay scheme where first occurs beta emission, and as result created the Ni-60 nucleus in the excited state, which passes in stable condition, releasing two gamma rays with energy 1170 keV and 1330 keV and halving period 5.27 years (Cobalt-60 (2009).
Reference
Canberra (2001)Exploranium GR130 Minispec, User Manual.
Cobalt-60 (2009), Industrial Radioactive Source Materials Data, QSA Global.
Dollani K, (2007) Dosimetry and radiation protection, Pegi, Tirana, Albania.
International Atomic Energy Agency (2008), The management system for the processing, handling and storage of radioactive waste, Safety Guide Series No. GS-G-3.3, IAEA, 2008.
Unger LM, Trubey DK, (1982) Specific Gamma Ray Dose Constant for Nuclides Important to Dosimetry and Radiological Assessment., Oak Ridge National Laboratory.
