Old uranium and radium production sites in Portugal were investigated to determine concentrations of uranium series radionuclides in mining and milling waste, mine drainage, and in surrounding environment. It was found that the ingestion of horticulture products grown with irrigation water from contaminated wells, combined with radon inhalation and enhanced ambient radiation doses could be the origin of radiation exposure of members of the population exceeding radiation dose limits. Site clean-up and environmental remediation measures were applied in many of those legacy sites, including coverage of tailings, continued treatment of mine water drainage, and removal of contaminated materials. These remediation measures reduced local contamination and the exposure of population to radioactivity, contributing to improved radiation safety. Lessons to retain and procedures currently recommended to avoid generating new uranium legacies are summarized.

1. Environmental Contamination from Uranium Production Facilities and their Remediation. Proceedings of an International Workshop, Proceedings of an International workshop, IAEA, Vienna, Austria, 2005.
   Retrieved from: https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1228_web.pdf;
   Retrieved on: Jan. 20, 2018
2. R. Hähne, S. Murphy, J. J. Vrijen, “State and prospects of closure and remediation of tailings deposits from uranium ore processing and heap leaching in Europe,” in The Uranium Mining Remediation Exchange Group: Selected Papers 1995–2007, Vienna, Austria: IAEA, 2011, pp. 7 – 27.
   Retrieved from: https://www-pub.iaea.org/MTCD/Publications/PDF/P_1524_CD/PDF/STI_PUB_1431.pdf;
   Retrieved on: Jan. 10, 2018
3. Managing Environmental and Health Impacts of Uranium Mining, No. 7062, OECD NEA, Boulogne-Billancourt, France, 2014.
   Retrieved from: https://www.oecd-nea.org/ndd/pubs/2014/7062-mehium.pdf;
   Retrieved on: Jan. 10, 2018
4. F. P. Carvalho, “Past uranium mining in Portugal: legacy, environmental remediation and radioactivity Monitoring,” in The Uranium Mining Remediation Exchange Group: Selected Papers 1995–2007, Vienna, Austria: IAEA, 2011, pp. 145 – 155.
   Retrieved from: https://www-pub.iaea.org/MTCD/Publications/PDF/P_1524_CD/PDF/STI_PUB_1431.pdf;
   Retrieved on: Jan. 10, 2018
5. F. P. Carvalho, “Environmental Radioactive Impact Associated to Uranium Production,” Am. J. Environ. Sci. vol. 7, no. 6, pp. 547 – 553, 2011.
   DOI: 10.3844/ajessp.2011.547.553
6. J. M. Falcão et al., Minas de Uranio e seus Resíduos: Efeitos na Saúde da População, Relatório Científico I, Instituto Superior Técnico, Lisboa, Portugal, 2005. (J. M. Falcão et al., “Uranium mines and their residues: Effects on the public health,” Scientific Report I, Institute of technology, Lisbon, Portigal, 2005.)
   Retrieved from: http://www.itn.pt/docum/relat/minurar/2005-MinUrar-relatorio1.pdf;
   Retrieved on: Jan. 10, 2018
7. J. M. Falcão et al., “Minas de Uranio e seus Resíduos: Efeitos na Saúde da População,” Relatório Científico II, Instituto Superior Técnico, Lisboa, Portugal, 2007. (J. M. Falcão et al., “Uranium Mines and their residues: Effects on the public heath,” Scientific Report II, Institute of technology, Lisbon, Portugal, 2007.)
   Retrieved from: http://www.itn.pt/docum/relat/minurar/2007-MinUrar-relatorio2.pdf;
   Retrieved on: Jan. 11, 2018
8. F. P. Carvalho, “The National Radioactivity Monitoring Program for the Regions of Uranium Mines and Uranium Legacy Sites in Portugal,” Procedia Earth Planet. Sci., vol. 8, pp. 33 – 37, 2014.
   DOI: 10.1016/j.proeps.2014.05.008
9. A herança das minas abandonadas, Lisboa, Portugal: DGEG & EDM, 2011. (The legacy of abandoned mines, Lisboa, Portugal: DGEG & EDM, 2011.)
   Retrieved from: http://edm.pt/wp-content/uploads/2017/03/livro_edm.pdf;
   Retrieved on: Jan 11, 2018
10. F. P. Carvalho, J. M. Oliveira, M. Malta, “Analyses of radionuclides in soil, water and agriculture products near the Urgeiriça uranium mine in Portugal,” J. Radioanal. Nucl. Chem., vol. 281, no. 3, pp. 479 – 484, Sep. 2009.
    DOI: 10.1007/s10967-009-0027-5
11. F. P. Carvalho et al., “Radioactive survey in former uranium mining areas in Portugal,” in Proc. International Workshop on Environmental Contamination from Uranium Production Facilities and Remediation Measures, Lisbon, Portugal, 2004, pp. 11 – 13.
    Retrieved from: https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1228_web.pdf;
    Retrieved on: Jan. 11, 2018
12. F. P. Carvalho et al., “Contamination of hydrographical basins in uranium mining areas of Portugal,” in Uranium in the Environment: Mining Impacts and Consequences, B. J. Merkel, A. Hasche-Berge, Eds., Berlin, Germany: Springer-Verlag, 2006, ch. 70, pp. 691 – 702.
    DOI: 10.1007/3-540-28367-6_70
13. F. P. Carvalho, J. M. Oliveira, I. Faria, “Alpha Emitting Radionuclides in Drainage from Quinta do Bispo and Cunha Baixa Uranium Mines (Portugal) and Associated Radiotoxicological Risk,” Bull. Environ. Contam. Toxicol., vol. 83, no. 5, pp. 668 – 673, Nov. 2009.
    DOI: 10.1007/s00128-009-9808-3
    PMid: 19590808
14. F. P. Carvalho, J. M. Oliveira, M. O. Neves, M. M. Abreu, E. M. Vicente, “Soil to plant (Solanum tuberosum L.) radionuclide transfer in the vicinity of an old uranium mine,” Geochem. Explor. Env. A,vol. 9, no. 3, pp. 275 – 278, 2009.
    DOI: 10.1144/1467-7873/09-213
15. F. P. Carvalho, J. M. Oliveira, M. Malta, “Radioactivity in Soils and Vegetables from Uranium Mining Regions,” Procedia Earth Planet. Sci., vol. 8, pp. 38 – 42, 2014.
    DOI: 10.1016/j.proeps.2014.05.009
16. F. P. Carvalho, J. M. Oliveira, M. Malta, “Intake of Radionuclides with the Diet in Uranium Mining Areas,” Procedia Earth Planet. Sci., vol. 8, pp. 43 – 47, 2014.
    DOI: 10.1016/j.proeps.2014.05.010
17. F. P. Carvalho, J. M. Oliveira, M. Malta, “Radioactivity in Iberian Rivers with Uranium Mining Activities in their Catchment Areas,” Procedia Earth Planet. Sci., vol.8, pp. 48 – 52, 2014.
    DOI: 10.1016/j.proeps.2014.05.011
18. F. P. Carvalho et al., “Radioactivity in the environment around past radium and uranium mining sites of Portugal,” J. Environ. Radioact., vol. 96, no. 1-3, pp. 39 – 46, Jul-Sep. 2007.
    DOI: 10.1016/j.jenvrad.2007.01.016
    PMid: 17433852
19. F. P. Carvalho, J. M. Oliveira, M. Malta, “Radioactivity and Water Quality in Areas of Old Uranium Mines (Viseu, Portugal),” Water Air Soil Pollut., vol. 227, no. 8, pp. 227 – 252, Aug. 2016.
    DOI: 10.1007/s11270-016-2948-2
20. F. P. Carvalho, J. M. Oliveira, M. Malta, “Preliminary assessment of uranium mining legacy and environmental radioactivity levels in Sabugal region, Portugal,” Int. J. Energ. Environmental Engineering, vol. 7, no. 4, pp. 399 – 408, Dec. 2016.
    DOI: 10.1007/s40095-016-0219-z
21. Radiation protection and safety of radiation sources: international basic safety standards, General Safety Requirements No. GSR Part 3, IAEA, Vienna, Austria, 2014.
    Retrieved from: https://www-pub.iaea.org/mtcd/publications/pdf/pub1578_web-57265295.pdf;
    Retrieved on: Jan. 11, 2018
22. Sources and effects of ionizing radiation, vol. 1, UNSCEAR Report (A/55/46), UNSCEAR, New York (NY), USA, 2000.
    Retrieved from: http://www.unscear.org/docs/publications/2000/UNSCEAR_2000_Report_Vol.I.pdf; Retrieved on: Jan. 12, 2017
23. F. P. Carvalho, J. M. Oliveira, M. Malta “Radon in a uranium bearing region of Portugal,” in Book of Abstr. 5^th Int. Conf. Radiation and Applications in Various Fields of research (RAD 2017), Budva, Montenegro, 2017, p. 452.
    Retrieved from: http://www.rad-conference.org/helper/download.php?
    file=../pdf/Book%20of%20Abstracts%20RAD%202017.pdf;
    Retrieved on: Jan. 15, 2018
24. WHO handbook on indoor radon: a public health perspective, WN 615, WHO, Geneva, Switzerland, 2009.
    Retrieved from: http://apps.who.int/iris/bitstream/10665/44149/1/9789241547673_eng.pdf;
    Retrieved on: Jan. 12, 2017

The use of the radio-luminescence (RL) method for radiation-induced processes in magnesium aluminates spinel crystals (MgO∙nAl₂O₃) of different composition doped with transition metals (Mn, Cr, and Fe) was investigated. The RL spectra demonstrate bands related to the intrinsic defects, such as anti-site defects (263 nm) and F-type centers (~360 nm). Transition metal (TM) ions substituting the crystal-forming ions in the tetra- and octahedral sites show the emission due to electron transitions in doped ions, particularly, band at 520 nm identified with the transition in Mn²⁺ in tetrahedral positions and the emission in the red spectral region (consisting of zero-phonon line at 686.6 nm and phonon-assisted lines) related to the transition in Cr³⁺ ions at the octahedral position. Based on the data on the quenching UV luminescence in stoichiometric crystals doped with TM, we suggest the partial ordering of this type of crystals. The enhancement of Cr³⁺ luminescence in stoichiometric spinel crystals doped with manganese and iron supports this suggestion on the ordering of the spinel crystals by doping with some TM’s. The existence of a large number of non-stoichiometric cationic vacancies in non-stoichiometric spinel crystals prevents the formation of an ordered structure.

1. R. P. Gupta, “Radiation-Induced Cation Disorder in the Spinel MgAl2O4,” J. Nucl. Mater., vol. 358, no. 1, pp. 35 – 39, Nov. 2006.
   DOI: 10.1016/j.jnucmat.2006.05.3055
2. A. Krell, K. Waetzig, J. Klimke, “Influence of the Structure of MgO∙nAl2O3 Spinel Lattices on Transparent Ceramics Processing and Properties,” J. Eur. Ceram. Soc., vol. 32, no. 11, pp. 2887 – 2898, Aug. 2012.
   DOI: 10.1016/j.jeurceramsoc.2012.02.054
3. H. Aizava et al., “Characteristics of Chromium Doped Spinel Crystals for a Fiber-Optic Thermometer Application,” Rev. Sci. Instrum., vol. 73, no. 8, pp. 3089 – 3092, Aug. 2002.
   DOI: 10.1063/1.1491998
4. Y. Fujimoto et al., “Vanadium-Doped MgAl2O4 Crystals as White Light Source,” J. Lumin., vol. 128, no. 3, pp. 282 – 286, Mar. 2008.
   DOI: 10.1016/j.jlumion.2007.07.022
5. T. Katsumata et al., “X-ray Excited Optical Luminescence from Mn Doped Spinel Crystals,” ECS Solid State Let., vol. 3, no. 7, pp. R23 – R25, May 2014.
   DOI: 10.1149/2.0011407ssl
6. R. Martignago, A. Dal Negro, S. Carbonin, “How Cr3+ and Fe3+ Affect Mg-Al Order-Disorder Transformation at High Temperature in Natural Spinels,” Phys. Chem. Minerals, vol. 30, no. 7, pp. 401 – 408, Aug. 2003.
   DOI: 10.1007/s00269-003-0336-0
7. A. Lorincz, M. Puma, F. J. James, J. H. Crawford, Jr., “Thermally Stimulated Processes Involving Defects in γ- and X-irradiated spinel (MgAl2O4),” J. Appl. Phys., vol. 53, no. 2, pp. 927 – 932, 1982.
   DOI: 10.1063/1.330562
8. V. T. Gritsyna, Yu. G. Kazarinov, V. A. Kobyakov, I. E, Reimanis, “Radiation-induced luminescence in magnesium aluminate spinel crystals and ceramics,” Nucl. Instr. Meth. B, vol. 250, no. 1-2, pp. 342 – 348, Sep. 2006.
   DOI: 10.1016/j.nimb.2006.04.135
9. J. M. G. Tijero, A. Ibarra, “Use of Luminescence of Mn2+ and Cr3+ in Probing the Disordering Process in MgAl2O4 Spinels,” J. Phys. Chem. Solids, vol. 54, no. 2, pp. 203 – 207, Feb. 1993.
   DOI: 10.1016/0022-3697(93)90309-F
10. G. I. Belykh, V. T. Gritsyna, L. A. Lytvynov, V. B. Kol`ner, “Structural and mechanical characteristics of magnesium-aluminate spinel crystals grown by Verneuil and Czochralski methods,” Funct. Mater., vol. 12, no. 3, pp. 447 – 453, 2005.
    Retrieved from: http://www.functmaterials.org.ua/contents/12-3/fm123-06.pdf;
    Retrieved on: Jan 25, 2018
11. V. Skvortsova, N. Mironova-Ulmane, U. Ulmanis, “Neutron irradiation influence on magnesium aluminum spinel inversion,” Nucl. Instr. Meth. B, vol. 191, no. 1-4, pp. 256 – 260, May 2002.
    DOI: 10.1016/S0168-583X(02)00571-2
12. V. T. Gritsyna, I. V. Afanasyev-Charkin, V. A. Kobyakov, K.E. Sickafus, “Structure and Electronic States of Defects in Spinel of Different Compositions MgO·nAl2O3:Me,” J. Am. Ceram. Soc., vol. 82, no. 12, pp. 3365 – 3373, Dec. 1999.
    DOI: 10.1111/j.1151-2916.1999.tb02252.x
13. V. Gritsyna, Yu. Kazarinov, A. Moskvitin, “Radio-Luminescence of Defects and Impurity Ions in Magnesium Aluminates Spinel,” Sol. St. Phen., vol. 200, pp. 203 – 208, Apr. 2013.
    DOI: 10.4028/www.scientific.net/SSP.200.203
14. S. S. Raj et al., “MgAl2O4 Spinel: Synthesis, Carbon Incorporation and Defect-Induced luminescence,” J. Mol. Struct., vol. 1089, pp. 81 – 85, 2015.
    DOI: 10.1016/j.molstruc.2015.02.002
15. N. Mironova, V. Skvortsova, A. Smirnovs, L. Cugunov, “Distribution of Manganese Ions in Magnesium-Aluminum Spinels of Different Compositions,” Optical Mater., vol. 6, no. 3, pp. 225 – 232, Sep. 1996.
    DOI: 10.1016/0925-3467(96)00037-7
16. S. Lucchesi, A. Della Giusta, “Crystal chemistry of non-stoichiometric Mg —AI synthetic spinels,” Z. Kristallogr. Cryst. Mater., vol. 209, no. 9, pp. 714 – 719, Sep. 1994.
    DOI: 10.1524/zkri.1994.209.9.714
17. A. Tomita et al., “Luminescence Channels of Manganese-Doped Spinel,” J. Luminesc., vol. 109, no. 1, pp. 19 – 24, Jul. 2004.
    DOI: 10.1016/j.jlumin.2003.12.049
18. T. Sakuma et al., “Compositional variation of photoluminescence from Mn doped MgAl2O4 Spinel,” Opt. mater., vol. 27, pp. 302 – 305, Nov. 2014.
    DOI: 10.1016/j.optmat.2014.06.014
19. J. Sima, “(Non)luminescent Properties of Iron Compounds,” Acta Chimica Slovaca, vol. 8, no. 2, pp. 126 – 132, Oct. 2015.
    DOI: 10.1515/ACS-2015-0022
20. C. R. Varney et al., “Strong visible and Near Infrared Luminescence in Undoped YAG Single Crystals,” AIP Adv., vol. 1, no. 4, 042170, 2011.
    DOI: 10.1063/1.3671646

An emergence of ¹³¹I in ambient air might be one of the first signs of a mishap. Even though precautions are clearly established, nuclear power plant accidents or any radioactive threat might occur. Iodine in the human body preferentially concentrates in the thyroid, so ¹³¹I is frequently used in nuclear medicine to diagnose or cure problems with it. We have previously reported strong variability in health risk biomarkers detected in lymphocytes of patients after diagnostic and therapeutic I-131 applications. Now, we report cellular responses to a challenging high dose of X-rays applied in vitro, as well as the DNA repair capacity examined in lymphocytes isolated from whole blood samples collected from 41 subjects exposed to the diagnostic ¹³¹I dose, and 30 persons who were unexposed. The aim of the study was to find out if individual susceptibilities to ionizing radiation (IR), defined by molecular and cellular repair capacities, of persons diagnosed with very low I-131 doses are different from those observed in an unexposed control group, and how confounding factors – age, gender, family vulnerability to cancer, and polymorphism in genes associated with repair – affect it. he DNA repair competence assay was applied using the Comet method. The RD_T-DNA (residual DNA damage, percentage of unrepaired DNA during post irradiation incubation) was used as a biomarker of fast DNA repair on a molecular level and was compared to. SCE levels (sister chromatid exchanges) measured on a cellular level as biomarker associated with cellular repair via homologous recombination. On average, lymphocytes of the subgroup diagnosed by ¹³¹I expressed a statistically significant increase in repair efficiency of DNA damage induced by a challenging dose as compared to the average value from the respective unexposed control group. That increase was followed by a strong decrease in the percentage of cells with a significantly elevated number of SCE and frequency of cells with significantly elevated numbers of SCE (HFC- high frequency cells). The observed increase of DNA repair efficiency also corresponded to previously reported significant decreases of chromosome aberrations levels, and to MN frequencies known as biomarkers of health risk. Nevertheless, all investigated biomarkers were characterized by high variability between individual responses. Obtained results show a slight dependence on gender and the family’s predisposition to cancer, and a significant dependence on polymorphism in the XRCC1(194), XRCC1(399), and XRCC13(241) genes involved in DNA repair process. While it is necessary to increase the number of polymorphism studies, we propose a model of short-term biomarker battery applicable for triage and prediction of the health risk from any ionizing radiation exposure.

1. J. Gąsiorkiewicz et al., “Studies on response to the challenging dose of x-rays in lymphocytes of patients undergoing diagnosis and treatment with Iodine-131,” in NATO Science for Peace and Security Series – E: Human and Societal Dynamics: Rapid Diagnosis in Populations at Risk from Radiation and Chemicals, vol. 73, A. Cebulska-Wasilewska, A. N. Osipov, F. Darroudi, Eds., Amsterdam, Netherlands: IOS Press, 2010,
2. A. Cebulska-Wasilewska, J. Miszczyk, Z. Drag, J. K. Kim, “Health Risk Impact due to Exposure to ¹³¹I with Low and High Doses Evaluated with Micronucleus Assay,” J. Korean Radiat. Ind., vol. 5, no. 4. pp. 331 – 335, 2011.
3. A. Cebulska-Wasilewska, M. Krzysiek G. Krajewska, A. Stępień, P.Krajewski, “Retrospective biological dosimetry at low and high doses of radiation and radioiodine impact on individual susceptibility to ionizing radiation, Genome Integrity, vol. 8, no. 1, pp. 2 – 12, Jan. 2017.
   DOI: 10.4103/2041-9414.198906
   PMid: 28250909
   PMCid: PMC5320787
4. Oncogene Diagnostics, Oncogene Diagnostics, Krakow, Poland.
   Retrieved from: http://www.oncogene.pl;
   Retrieved on: Jan. 17, 2017
5. A. Cebulska-Wasilewska, “Response to challenging Dose of X-rays as a Predictive Assay for Molecular Epidemiology,” Mutat. Res. Rev. Mutat. Res., vol. 544, no. 2-3, pp. 289 – 297, Nov. 2003.
   DOI: 10.1016/j.mrrev.2003.07.003
6. A. Cebulska-Wasilewska, J. Rachtan, Z. Rudek, Z. Drag, “Cytogenetic damage detected in lymphocytes of donors from Małopolska region in Poland and cancer incidence in the follow-up studies,” in Environmental Health in Central and Eastern Europe, K. C. Donnelly et al., Eds., Berlin, Germany: Springer, 2006, ch. 7, pp. 53 – 64.
   DOI: 10.1007/1-4020-4845-9
7. K. H. Chadwick, H. P. Leenhouts, The Molecular Theory of Radiation Biology, Berlin, Germany: Springer-Verlag, 1981.
   DOI: 10.1007/978-3-642-81519-5

Three NaI(Tl) detectors and two pairs of NaI(Tl) detectors at an angle of 90° – from the six-crystal spectrometer PRIPJAT-2M (Faculty of Natural Sciences and Mathematics, University of Montenegro, Podgorica), were used to determine registration efficiencies for the most intense gamma rays in de-excitation of ¹³⁴Ba, following beta minus decay of ¹³⁴Cs. The ¹³⁴Cs liquid calibration standard was used for acquiring spectra over 18 000 s real time in the energy range (200-3000) keV – in the integral, non-coincident and mode of double gamma-gamma coincidences. All the spectra from individual detectors and detector pairs in all the counting modes clearly showed peaks at the 605 and 796 keV. The experimental registration efficiency of the 605 keV gamma ray by individual detectors in different modes of counting was found to be with an average of 0.055 (integral), 0.032 (non-coincident) and 0.021 (double coincidences), whilst in the case of two detector pairs – 0.112 (integral), 0.065 (non-coincident) and 0.042 (double coincidences). In regards to the 796 keV, average detection efficiencies were 0.04 (integral), 0.026 (non-coincident) and 0.013 (double coincidences) – in the case of individual detectors, and 0.076 (integral), 0.048 (non-coincident) and 0.026 (double coincidences) – for the detector pairs. Obtained results are baselines for the future development of the coincidence method for ¹³⁴Cs measurement – using multidetector systems with measuring geometry close to 4π, with the 796 keV photopeak in a coincidence mode as appropriate for ¹³⁴Cs detection in a sample containing ¹³⁷Cs and decay products of ²²⁶Ra and ²³²Th.

1. Y. Unnoa, T. Sanamib, M. Hagiwarab, S. Sasakib, A. Yunokia, “Application of beta coincidence to nuclide identification of radioactive samples contaminated by the accident at the Fukushima Nuclear Power Plant,” Prog. Nucl. Sci. Tech., vol. 4, pp. 90 – 93, 2014.
   DOI: 10.15669/pnst.4.90
2. Recommended data, LNHB, Paris, France, 2017.
   Retrieved from: http://www.nucleide.org/DDEP_WG/DDEPdata.htm;
   Retrieved on: Jan. 15, 2018
3. E. L. Grigorescu, P. de Felice, A. C. Razdolescu, A. Luca, “Low-level gamma spectrometry using beta coincidence and Compton suppression,” Appl. Radiat. Isot., vol. 61, n0. 2-3, pp. 191 – 195, Aug-Sep. 2004.
   DOI: 10.1016/j.apradiso.2004.03.044
   PMid: 15177343
4. С. К. Андрухович, А. В. Берестов, В. И. Гутко, А. М. Хильманович, “Высокочувствительные многодетекторные гамма спектрометры ПРИПЯТЬ,” Препринт Института физики, АН БССР, Минск, Беларусь, 1995 (S. K. Andrukhovich, A. V. Berestov, V. I. Gutko, A. M. Hil’manovich, “High sensitive multidetector gamma spectrometers PRIPYAT,” Preprint of the Institute of Physics, AN BSSR, Minsk, Belarus, 1995.)
5. N. Svrkota, N. M. Antović, T. Andjelić, “Osnovi koincidentnog metoda mjerenja cezijuma-134,” u Černobilj, 30 godina posle, G. Pantelić, Ur., Beograd, Srbija:Društvo za zaštitu od zračenja Srbije i Crne Gore i Institut Vinča, str. 278 – 286, 2016. (N. Svrkota, N. M. Antović, T. Andjelić, “Basic research for coincidence method of Cs-134 measurement,” in Chernobyl, 30 years after, G. Pantelić, Ed., Belgrade, Serbia:Society for Radiation Protection of Serbia and Montenegro and Vinča Institute, 2016, pp. 278 – 286.)
   Retrieved from: https://www.researchgate.net/publication/309772261_Cernobilj_30_godina_posle;
   Retrieved on: Jan. 15, 2018
6. J. Mijušković, “Efikasnost detekcije ¹³⁴Cs parovima detektora pod uglom od 90° i 180°,” Spec. rad, Univerzitet Crne Gore, Prirodno-matematički fakultet, Podgorica, Crna Gora, 2016. (J. Mijušković, “Detection efficiency of ¹³⁴Cs by detector pairs at angles of 90° and 180°”, Spec. Thesis, University of Montenegro, Faculty of Natural Sciences and Mathematics, Podgorica, Montenegrom 2016.)
7. N. M. Antović, N. Svrkota, “Detection efficiencies of ²²⁶Ra and ²³²Th in different modes of counting of the PRIPYAT-2M spectrometer,” Nucl. Technol. Radiat. Prot., vol. 24, no. 2, pp. 109 – 118, Jul. 2009.
   DOI: 10.2298/NTRP0902109A
8. M. C. Cook, M. J. Stukel, W. Zhang, J.-F. Mercier, M. W. Cooke, “The determination of Fukushima-derived cesium-134 and cesium-137 in Japanese green tea samples and their distribution subsequent to simulated beverage preparation,” J. Environ. Radioactiv., vol. 153, pp. 23 – 30, Mar. 2016.
   DOI: 10.1016/j.jenvrad.2015.12.010
   PMid: 26714059

Therapeutic treatment with radionuclides leads to radiation exposure. Exposure in the vicinity of patients undergoing radionuclide therapy for thyroid carcinoma needs to be discussed due to the high amount of radioactivity administered to the patient. This study presents the estimations of annual effective doses received by members of the public not directly involved in treatment procedures after patient discharge from our Department of Nuclear Medicine. After a few days of in-patient stay, the exposure is in general very low and a dedicated supervision of the patient after discharge is dispensable.

1. J. C. Harbert and N. Wells, “Radiation exposure to the family of radioactive patient,” J. Nucl. Med., vol. 15, no. 10, pp. 887 – 888, Oct. 1974.
   PMid: 4418007
2. C. M. Culver and H. J. Dworkin, “Radiation safety considerations for post-Iodine-131 hyperthyroid therapy,” J. Nucl. Med., vol 32, no. 1, pp. 169 – 173, Jan. 1991.
   PMid: 1988627
3. M. Salvatori and G. Lucignani, “Radiation exposure, protection and risk from nuclear medicine procedures,” Eur. J. Nucl. Med., vol 37, no. 6, pp 1225 – 1231, Jun. 2010.
   DOI: 10.1007/s00259-010-1474-5
   PMid: 20411257
4. M. Pacilio, L. Bianciardia, V. Panichelli, G. Argiro, and C. Cipriani, “Management of ¹³¹I therapy for thyroid cancer: cumulative dose from in-patients, discharge planning and personnel requirements,” Nuc. Med. Commun., vol. 26, no. 7, pp 623 – 631, Jul. 2005.
   DOI: 10.1097/01.mnm.0000167909.69095.c9
   PMid: 15942483
5. S. F. Barrington, A. G. Kettle, M. J. O’Doherty, C. P. Wells, A. J. R. Somer, and A. J. Coakley, “Radiation does rates from patients receiving iodine-131 therapy for carcinoma of the thyroid,” Eur. J. Nucl. Med., vol. 23, no. 2, pp. 123 – 130, Feb. 1996.
   DOI: 10.1007/BF01731834
   PMid: 8925845
6. S. F. Barrington et al., “Radiation exposure of the families of outpatients treated with radioiodine (iodine-131) for hyperthyroidism,” Eur. J. Nucl. Med., vol. 26, no. 7, pp. 686 – 692, Jun. 1999.
   DOI: 10.1007/s002590050438
   PMid: 10398815
7. P. W. Grigsby, B. A. Siegel, S. Baker, J. O. Eichling, “Radiation exposure from outpatient radioactive iodine (¹³¹I) therapy for thyroid carcinoma,” J. Am. Med. Assoc., vol. 283, no. 17, pp. 2272 – 2274, May 2000.
   DOI: 10.1001/jama.283.17.2272
   PMid: 10807387
8. D. D`Alessio, C. Giliberti, M. Benassi, L. Strigari, “Potential third-party radiation exposure from patients undergoing therapy with ¹³¹I for thyroid cancer or metastases,” Health Phys., vol. 108, no. 3, pp. 319 – 325, Mar. 2015.
   DOI: 10.1097/HP.0000000000000210
   PMid: 25627943
9. F. Sudbrock, F. Boldt, C. Kobe, J. Hammes, W. Eschner, H. Schicha, “Die Strahlenexposition in der Umgebung von Patienten nach Applikation verschiedener Radiopharmaka. Teil 2 Nuklearmedizinische Therapien,” Nuklearmedizin, vol. 48, pp. 17 – 25, 2009. (F. Sudbrock, F. Boldt, C. Kobe, J. Hammes, W. Eschner, H. Schicha, “Radiation exposure in the environment of patients after application of radiopharmaceuticals,” Nucl. med., vol. 48, pp. 17 – 25, 2009.).
10. K. Uhrhan, A. Drzezga, and F. Sudbrock, “The patient as a radioactive source: an intercomparison of survey meters for measurements in nuclear medicine,” Radiat. Prot. Dosimetry, vol. 162, no. 1-2, pp. 101 – 104, Jul. 2014.
    DOI: 10.1093/rpd/ncu238
    PMid: 25071244
11. J. Willegaignon de Amorim de Carvalho et al., “Could the treatment of differentiated thyroid carcinoma with 3.7 and 5.5 GBq of (¹³¹I) NaI, on an outpatient basis, be safe?” Nucl. Med. Commun., vol. 30, no. 7, pp. 533 – 541, Jul. 2009.
    DOI: 10.1097/MNM.0b013e32832b79bc
    PMid: 19436231
12. C. E. Williams and A. F. Woodward, “Management of the helpless patient after radioiodine ablation therapy - are we being too strict?” Nucl. Med. Comm. vol. 26, no. 10, pp. 925 – 928, Oct. 2005.
    DOI: 10.1097/00006231-200510000-00012
    PMid: 16160653
13. C. J. Marriott, C. E. Webber, and K. Y. Gulenchyn, “Radiation exposure for ‘caregivers’ during high-dose outpatient radioiodine therapy,” Rad. Prot. Dosimetry, vol 123, no. 1, pp. 62 – 67, Jan. 2007.
    DOI: 10.1093/rpd/ncl084
    PMid: 16825250
14. K. H. Jeong et al., “Estimation of external radiation dose to caregivers of patients treated with radioiodine after thyroidectomy,” Health Phys., vol. 106, no. 4, pp. 466 – 474, Apr. 2014.
    DOI: 10.1097/HP.0b013e3182a415eb
    PMid: 24562067
15. K. Schomäcker et al., “Exhalation of ¹³¹I after radioiodine therapy: measurements in exhaled air and dosimetric considerations,” Eur. J. Nucl. Med. Mol. Im., vol. 38, no. 12, pp. 2165 – 2172, Dec. 2011.
    DOI: 10.1007/s00259-011-1888-8
    PMid: 21847636

The biggest risks in a mission to Mars are the long periods of time with the lack of gravity, the psychological effects due to isolation, the risk of contamination by diseases in confined space, and exposure to high doses of radiation. It is recognized that the latter poses the greatest scientific and technological challenge to a viable mission. In this work, we present estimates of the equivalent dose in an astronaut for three mission-to-Mars profiles proposed by NASA. For this, we performed Monte Carlo simulations of the energy deposited in the ICRU sphere taking into account the main radiation sources in space using the Geant4 simulation toolkit. The results show that the introduction of 10 cm equivalent Al shielding significantly reduces the equivalent dose, although our estimates are still above the dose limits adopted by NASA. These results show, however, that the values are in the range for optimization in terms of shielding solutions, as well as the choice of the most appropriate mission trajectories to minimize the dose to astronauts.

1. NASA’s Journey to Mars: Pioneering Next Steps in Space Exploration, NASA, Washington (DC), USA: 2015.
   Retrieved from: https://www.nasa.gov/sites/default/files/atoms/files/journey-to-mars-next-steps-20151008_508.pdf;
   Retrieved on: Dec. 10, 2017
2. S. M.-Lawlor et al., “Overview of energetic particle hazards during prospective manned missions to Mars,” Planet. Space Sci., vol. 63-64, pp. 123 – 132, Apr. 2012.
   DOI: 10.1016/j.pss.2011.06.017
3. M. Durante, “Space radiation protection: Destination Mars,” Life Sci. Space Res., no. 1, pp. 2 – 9, Apr. 2014.
   DOI: 10.1016/j.lssr.2014.01.002
   PMid: 26432587
4. J. A. Simpson, “Elemental and isotopic composition of the galactic cosmic rays,” Ann. Rev. Nucl. Part. Sci. vol. 33, pp. 323 – 381, Dec. 1983.
   DOI: 10.1146/annurev.ns.33.120183.001543
5. Assessment of radiation exposure of astronauts in space, ICRP Publication 123, ICRP, Ottawa, Canada, 2013.
   DOI: 10.1016/j.icrp.2013.05.004
   PMid: 23958389
6. N. Yu Ganushkina et al., “Locations of boundaries of outer and inner radiation belts as observed by cluster and double star,” J. Geophys. Res. A, vol. 116, no. A9, A09234, Sep. 2011.
   DOI: 10.1029/2010JA016376
7. D. V. Reames, “The two sources of solar energetic particles,” Space Sci. Rev., no. 175, no. 1-4, pp. 53 – 92, Jun. 2013.
   DOI: 10.1007/s11214-013-9958-9
8. S. K. Antiochos et al., “A model for solar coronal mass ejection,” Astrophys. J., vol. 510, no. 1, pp. 485 – 493, Jan. 1999.
   DOI: 10.1086/306563
9. M. J. Aschwanden, “The localization of particle acceleration sites in solar flares and CMEs,” Space Sci. Rev., vol. 124, no. 1-4, pp. 361 – 372, Jun. 2006.
   DOI: 10.1007/s11214-006-9095-9
10. N. Gopalswamy et al., “Type II radio bursts and energetic solar eruptions,” J. Geophys. Res.-Space, vol. 110, no. A9, A09s00, Sep. 2005.
    DOI: 10.1029/2005JA011158
11. S. C. R. Rafkin et al., “Diurnal variations of energetic particle radiation at the surface of Mars as observed by the Mars Science Laboratory Radiation Assessment Detector,” J. Geophys. Res.-Planet, vol. 119, no. 6, pp. 1345 – 1358, Jun. 2014.
    DOI: 10.1002/2013JE004525
12. Wimmer-Schweingruber et al., “On Determining the Zenith-Angle Dependence of the Martian Radiation Environment at Gale Crater Altitudes,” Geophys. Res. Lett., vol. 42, no. 24, pp. 10557 – 10564, Dec. 2015.
    DOI: 10.1002/2015GL066664
13. S. M.-Lawlor et al, “Characterization of the particle radiation environment at three potential landing sites on Mars using ESA’s MEREM models,” Icarus, vol. 218, no. 1, pp. 723 – 734, Mar. 2012.
    DOI: 10.1016/j.icarus.2011.04.004
14. P. Gonçalves et al., “MARSREM: the Mars Energetic Radiation Environment Models,” in Proc. 31st Int. Cosmic Ray Conf. (ICRC), Łódź, Poland, 2010, pp. 1 – 4.
15. D. M. Hassler et al., “Mars` surface radiation environment measured with the Mars Science Laboratory`s curiosity rover,” Science, vol. 343, no. 6169, 1244797, Jan. 2014.
    DOI: 10.1126/science.1244797
    PMid: 24324275
16. D. R. Williams, A crewed mission to Mars, NASA, Washington (DC), USA, 2015.
    Retrieved from: http://nssdc.gsfc.nasa.gov/planetary/mars/marsprof.html;
    Retrieved on: Oct. 10, 2016
17. S. Agostinelli et al., “Geant4- simulation toolkit,” Nucl. Instr. Meth. Phys. Res. A, vol. 506, no. 3, pp. 250 – 303, Jul. 2003.
    DOI: 10.1016/S0168-9002(03)01368-8
18. J. Allison et al., “Geant4 developments and applications,” IEEE Trans. Nucl. Sci., no. 53, no. 1, pp. 270 – 278, Feb. 2006.
    DOI: 10.1109/TNS.2006.869826
19. Radiation Quantities and Units, ICRU Rep. 33, ICRU, Washington (DC), USA, 1980.
    DOI: 10.1002/jlcr.2580180918
20. S. Calders et al., Space environment information system (SPENVIS) version 4.6.9, European Space Agency, Paris, France, 2017.
    Retrieved from: https://www.spenvis.oma.be;
    Retrieved on: Jan. 17, 2018
21. R. A. Braeunig, “Apollo 11`s translunar trajectory and how they avoided the heart of the radiation belts,” braeuing.us, Mar. 24, 2016.
    Retrieved from: http://www.braeunig.us/apollo/apollo11TLI.htm;
    Retrieved on: Oct. 10, 2016.
22. B. Ehresmann et al., “Charged particle spectra measured during the transit to Mars with the Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)”, Life Sci. Space Res., no. 10, pp. 29 – 37, Aug. 2016.
    DOI: 10.1016/j.lssr.2016.07.001
    PMid: 27662785
23. The 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, ICRP, Ottawa, Canada, 2007.
    Retrieved from: https://www.sciencedirect.com/journal/annals-of-the-icrp/vol/37/issue/2;
    Retrieved on: Oct. 10, 2016
24. Basic Anatomical and Physiological Data for Use in Radiological Protection Reference Values, ICRP Publication 89, ICRP, Ottawa, Canada, 2002.
    Retrieved from: https://www.sciencedirect.com/journal/annals-of-the-icrp/vol/32/issue/3;
    Retrieved on: Oct. 10, 2016
25. Radiation Protection Guidance for Activities in Low-Earth Orbit, Report No. 132, NCRP, Bathesda (MD), USA, 2000.
26. Space environment (natural and artificial) – Galactic cosmic ray model, ISO 15390, May, 2004.
    Retrieved from: http://www.spacewx.com/Docs/ISO_PRF_15390_E.PDF;
    Retrieved on: Oct. 10, 2016
27. S. M. McLennan et al, “Elemental geochemistry of sedimentary rocks at Yellowknife Bay, Gale Crater, Mars,” Science, vol. 343, no. 6169, 1244734, Jan. 2014.
    DOI: 10.1126/science.1244734
    PMid: 24324274
28. D. M. Hassler et al, “Mars’ surface radiation environment measured with the Mars Science Laboratory’s Curiosity rover,” Science, vol. 343, no. 6169, 1244797, Jan. 2014.
    DOI: 10.1126/science.1244797
    PMid: 24324275
29. D. M. Hassler et al., “The Radiation Assessment Detector (RAD) investigation,” Space Sci. Rev., vol. 170, no. 1-4, pp. 503 – 558, Sep. 2012.
    DOI: 10.1007/s11214-012-9913-1
30. C. Zeitlin et al., “Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory,” Science, vol. 340, no. 6136, pp. 1080 – 1084, May 2013.
    DOI: 10.1126/science.1235989
    PMid: 23723233
31. J. Guo et al., “Variations of dose rate observed by MSL/RAD in transit to Mars,” Astron. Astrophys., vol. 577, A58, May 2015.
    DOI: 10.1051/0004-6361/201525680
32. A. Mrigakshi et al., “Estimation of Galactic Cosmic Ray exposure inside and outside the Earth’s magnetosphere during the recent solar minimumbetween solar cycles 23 and 24,” Adv. Space Res., vol. 52, no. 5, pp. 979 – 987, Sep. 2013.
    DOI: 10.1016/j.asr.2013.05.007

The authors’ contribution to this paper is to present a possible designing solution concept of the remote control robot for the decommissioning of the nuclear reactor horizontal fuel channels. In this paper, the authors present several properties of geometry, kinematics and dynamics of the robot movement into the reactor fuel channel and a few considerations required due to material thickness, according to the radiation protection procedures. The main stages of the dismantling operation in terms of operational safety are: positioning, coupling and locking, operating accordingly with the approved decommissioning procedures, sorting and storing the extracted items in the robot container. All operating steps are designed to be automated and performed by one robot which shall provide radiation protection during the dismantling stages, thus ensuring radiation protection of the workers. The operations are monitored by internal sensors and transducers, by pyrometer for temperature during the cutting process and video surveillance cameras for the dismantling components, in order to ensure assembly of operating facilities and a permanent control. The remote control robot radiation protection has a safety system able to extract the robot from the channel in case of a disruption of the blocking or decommissioning activities due to any error registered, in order to ensure the environmental and workers’ protection.

1. Assessment and management of ageing of major nuclear power plant components important to safety: CANDU reactor assemblies, IAEA-TECDOC-1197, IAEA, Vienna, Austria, 2001.
   Retrieved from: https://www-pub.iaea.org/MTCD/publications/PDF/te_1197_prn.pdf;
   Retrieved on: Jan. 10, 2018
2. Decommissioning of Nuclear Power Plants and Research Reactors, IAEA Safety Standard Series No. WS-G-2.1, IAEA, Vienna, Austria, 1999.
   Retrieved from: https://www-pub.iaea.org/MTCD/Publications/PDF/P079_scr.pdf;
   Retrieved on: Jan. 10, 2018
3. Atomic Energy of Canada Limited, AECL, Ottawa, Canada, 2014.
   Retrieved from: http://www.aecl.ca/en/home/news/news-archives/2014-10-10-launch-of-canadian-nuclear-
   laboratories.aspx;
   Retrieved on: Jan. 10, 2018
4. Nuclear Power Plant Design Characteristics, IAEA-TECDOC-1544, IAEA, Vienna, Austria, 2007.
   Retrieved from: https://www-pub.iaea.org/MTCD/Publications/PDF/te_1544_web.pdf;
   Retrieved on: Jan. 10, 2018
5. B. A. Cheadle, E. G. Price, “Operating performance of CANDU pressure tubes,” presented at the IAEA Technical Committee Meeting on the Exchange of Operational Safety Experience of Heavy Water Reactors, Vienna, Austria, Feb. 1989.
   Retrieved from: http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/23/059/23059653.pdf;
   Retrieved on: Jan. 10, 2018
6. K. Heyde, Basic Ideas and Concepts in Nuclear Physics: an introductory approach, Bristol, UK: Institute of Physics Publishing, 1994.
   Retrieved from: http://www.fisica.net/nuclear/basic_ideas_and_concepts_in_nuclear_physics_
   an_introductory_approach.pdf;
   Retrieved on: Jan. 10, 2018
7. R. G. Steed, Nuclear Power in Canada and Beyond, Renfrew, Canada: General Store Publishing House, 2007.
8. Fundamentals of power reactors, AECL, Ottawa, Canada, 1993.
   Retrieved from: https://canteach.candu.org/Content%20Library/Forms/AllItems.aspx;
   Retrieved on: Jan. 10, 2018
9. ANSTO Replacement Research Reactor Project: SAR Chapter 19 – Decommissioning, Rep. RRRP-7225-EBEAN-002-REV0-CHAPTER-19, ANSTO, Sydney, Australia, 2004.
   Retrieved from: https://www.arpansa.gov.au/sites/g/files/net3086/f/legacy/pubs/regulatory/opal/op/SAR/ch19.pdf;
   Retrieved on: Jan. 10, 2018
10. Enhanced CANDU 6: Technical Summary, SNC-LAVALIN, Montreal, Canada, 2015.
    Retrieved from: http://www.snclavalin.com/en/files/documents/publications/enhanced-candu-6-technical-
    summary_en.pdf;
    Retrieved on: Jan. 10, 2018
11. National Commission for Nuclear Activities Control. (Oct. 10, 1996). Law no. 111/1996 on the safe deployment, regulation, authorization and control of nuclear activities.
    Retrieved from: http://www.cncan.ro/assets/Legislatie/Law-no-111-of-19962006-final.doc;
    Retrieved on: Jan. 10. 2018
12. Comisia Nationala pentru Controlul Activitatilor Nucleare. (15.9.2002). NSN-15 Normele de dezafectare a obiectivelor și instala țiilor nucleare. (National Commission for Nuclear Activities Control. (Sep. 9, 2002). NSN-15 Rules for the decommissioning of objectives and nuclear installations.)
    Retrieved from: http://www.cncan.ro/assets/nsn/nsn15.pdf;
    Retrieved on: Jan. 15, 2018
13. S. Venkatapathi, A. Mehmi, H. Wong, “Pressure tube to end fitting roll expanded joints in CANDU PHWRS,” presented at the Int. Conf. on Expanded and Rolled Joint Technology, Toronto, Canada, Sep. 1993.
14. Assessment and management of ageing of major nuclear power plant components important to safety: CANDU reactor assemblies, IAEA-TEDOC-1197, IAEA, Vienna, Austria, 2001.
    Retrieved from: https://www-pub.iaea.org/MTCD/publications/PDF/te_1197_prn.pdf;
    Retrieved on: Jan. 10, 2018
15. Organization and Management for Decommissioning of Large Nuclear Facilities, IAEA Technical Reports Series No. 399, IAEA, Vienna, Austria, 2000.
    Retrieved from: https://www-pub.iaea.org/MTCD/Publications/PDF/TRS399_scr.pdf;
    Retrieved on: Jan. 10, 2018
16. Selection of decommissioning strategies: Issues and factors, IAEA-TECDOC-1478, IAEA, Vienna, Austria, 2005.
    Retrieved from: https://www-pub.iaea.org/MTCD/publications/PDF/TE_1478_web.pdf;
    Retrieved on: Jan. 11, 2018
17. State of the Art Technology for Decontamination and Dismantling of Nuclear Facilities, IAEA Technical Reports Series No. 395, IAEA, Vienna, Austria, 1999.
    Retrieved from: https://www-pub.iaea.org/mtcd/publications/pdf/trs395_scr/d395_part1_scr.pdf;
    Retrieved on: Jan. 11, 2018
18. Water channel reactor fuels and fuel channels: Design, performance, research and development, IAEA-TECDOC-997, IAEA, Vienna, Austria, 1996.
    Retrieved from: https://www-pub.iaea.org/MTCD/publications/PDF/te_997_prn.pdf;
    Retrieved on: Jan. 11, 2018
19. Heavy Water Reactors: Status and Projected Development, IAEA Technical Reports Series No. 407, IAEA, Vienna, Austria, 2002.
    Retrieved from: https://www-pub.iaea.org/MTCD/publications/PDF/TRS407_scr/D407_scr1.pdf;
    Retrieved on: Jan. 15, 2018
20. Preliminary decommissioning plan for the Point Lepreau generating station, Rep. N29-1387-003, TLG Services, Inc. Bridgewater (CT), USA, 2010.

A new technique for ⁹⁰Sr activity measurement in fuel-containing materials with no radiochemical methods was developed. ⁹⁰Sr content was measured in fuel fragments of various types. Probability of K_x-radiation formation during the radioactive decay with the emission of ⁹⁰Sr and ⁹⁰Y electrons was measured. A comparison to radiochemical research data was made. A non-radiochemical technique of simultaneous measurements of ⁹⁰Sr and ¹³⁷Cs activity in environmental samples based on spectrometric measurement of the electrons accompanying the isotope decay was proposed for measurements in situ (directly in places of radioactive contamination) and in vitro (in small living objects). Taking into account the contribution of ⁴⁰K electrons to the total activity of test samples, up to 15–20% improvement of the measurement accuracy for living beings is allowed, with ratio A (¹³⁷Cs)/A(⁹⁰Sr) being between 2 and 100. Also, the improvement of up to 10–15% for soil samples with changing the sample’s activity by four orders of magnitude is observed. The results of spectrometric measurements were confirmed by traditional radiochemical research. The proposed methods allow to execute prompt mass measurements of environment objects and small living objects directly in the places of radiation accidents. This is very important for the tasks of radioecological monitoring.

1. M. D. Bondarkov, A. M. Maximenko, V. А. Zhetonozhsky, “Non radiochemical technique for ⁹⁰Sr measurement,” Radioprotection, vol. 37, no. C1, pp. C1-927 – C1-931, Feb. 2002.
   DOI: 10.1051/radiopro/2002226
2. V. A. Zheltonozhskyi, N. V. Strilchuk, “Study of the dependence of the excitation probability of an atom in the β^--decay of the electron energy,” The RAS Journal, vol. 66, no. 10, pp. 1450, 2002.
3. А. И. Липская, М. В. Желтоножцкая, Н. В. Кулич и др., „Поведение радионуклидов в лесных экосистемах, прилегающих к 30-километровой зоне чаэс,“ Наукові праці. Серія Техногенна безпека, т. 185, но. 173, стр. 59 – 65, 2012. (A. I. Lypska, M. V. Zheltonozhska, N. V. Kulich et al.,“Behavior of radionuclides in the forest ecosystems adjacent to 30-km Chornobyl zone,” Proceedings. Industrial safety series, vol. 185, no. 173, pp. 59 – 65, 2012.)
   Retrieved from: http://tb.chdu.edu.ua/article/view/66220/61582;
   Retrieved on: Feb. 20, 2018
4. В. П. Хоменков, „Дослідження атомно-ядерних ефектів у процесі внутрішньої конверсії гамма-променів,“ дисерт. канд. фізико-математичних наук, Національна Академія Наук України, Інститут ядерних досліджень, Київ, Україна, 2003. (V. P. Khomenkov, “Research of atomic and nuclear effects in the process of internal conversion of gamma rays,” Cand. Sc. Dissertation, National Academy of Sciences of Ukraine, Institute for Nuclear Research, Kiev, Ukraine, 2003.)
5. E. Browne, R. B. Firestone, Table of Radioactive Isotopes, New York (NY), USA: John Wiley & Sons. Inc., 1986.
   DOI: 10.1002/bbpc.19870910459

Background. Observed from a global perspective, there is currently an increasing tendency directed towards protection, on the one hand, and efficient natural resources exploitation for the sake of daily society needs at the other. Whilst the contemporary environmental quality monitoring schemes at the national level recognize the significance of basic physical, chemical and biological parameters as environmental quality indicators, there is insufficient attention given to the radionuclide monitoring. Aims. Having the previous facts in mind, the aim of this paper is directed to: detailed analysis of sources of radionuclides in environment, mechanisms of their transfer in different environmental media and their final fate influencing environmental quality and environmental services. Also, the aim of this paper is to demonstrate the significance of radionuclide monitoring both from the perspective of environmental protection and natural resource availability. Methodology. The outcomes of this paper rely on the environmental quality reports and studies performed by numerous organizations, and it highlights the importance of interdisciplinary approach within the observed field.

1. Извештај о стању животне средине у Републици Србији за 2014. годину, Министарство пољопривреде и заштите животне средине, Београд, Србија, 2014. (Report on the state of the environment in the Republic of Serbia in the year 2014, Ministry of Algriculture and Environmental Protection, Belgrade, Serbia, 2014.)
   Retrieved from: http://www.sepa.gov.rs/download/Izvestaj2014.pdf;
   Retrieved on: Dec. 20, 2017
2. Народна Скупштина Републике Србије. (31. 5. 2011). Правилник о националној листи индикатора заштите животне средине. (National Assembly of the Republic of Serbia. (May 5, 2011). Regulations on national list of the indicators of the environmental protection.)
   Retrieved from: https://www.pravno-informacioni-sistem.rs/SlGlasnikPortal/reg/viewAct/744a766b-afb4-46c2-
   b30d-7ceb61cd391b;
   Retrieved on: Dec. 20, 2017
3. Народна Скупштина Републике Србије. (28.9.2012). Закон о заштити од јонизујућих зрачења и о нуклеарној сигурности. (National Assembly of the Republic of Serbia. (Sep. 28, 2012). Ionizing Radiation Protection and Nuclear Safety Law)
   Retrieved from: http://www.mpn.gov.rs/wp-content/uploads/2015/08/zastita_jonizujuca_zracenja
   _nuklearna_sigurnost_cir.pdf;
   Retrieved on: Dec. 20, 2017
4. Годишњи извештај о раду агенције за заштиту од јонизујућег зрачења и нуклеарну сигурност Србије за период од 01.01.2016 до 31.12.2016. године, Агенција за заштиту од јонизујућег зрачења и нуклеарну сигурност Србије, Београд, Србија, 2017. (Annual report on the activity of the Serbian Radiation Protection and Nuclear Safety Agency for the period from Jan. 1, 2016 to Dec. 31, 2016, Serbian Radiation Protection and Nuclear Safety Agency, Belgrade, Serbia, 2017.)
   Retrieved from: http://www.srbatom.gov.rs/srbatom/doc/God.%20izvestaj%20AJZ%202016.pdf;
   Retrieved from: May 17, 2017
5. Мониторинг радиоактивности животне средине у Републици Србији верзија 1.0, Агенција за заштиту од јонизујућег зрачења и нуклеарну сигурност Србије, Београд, Србија, 2016. (Monitoring of the environmental radioactivity in the Republic of Serbia version 1.0, Serbian Radiation Protection and Nuclear Safety Agency, Belgrade, Serbia, 2016.)
   Retrieved from: http://monradrs.srbatom.gov.rs/cir;
   Retrieved on: Jan. 16, 2017
6. S. Mušicki, V. Nikolić, D. Vasović, “Safety, security, hazard and risk – a conceptual approach,” in Procc. 7th DQM International Conference Life Cycle Engineering and Management (ICDQM-2016), Prijevor, Serbia, 2016. pp. 396 – 401.
7. J. Malenović Nikolić, D. Vasović, I. Filipović, S. Mušicki, I. Ristović, “Application of Project Management Process on Environmental Management System Improvement in Mining-Energy Complexes,” Energies, vol. 9, no. 12, 1071, Dec. 2016.
   DOI: 10.3390/en9121071
8. D. T. Long et al., “Aqueous geochemistry of groundwater in a region affected by Balkan endemic nephropathy,” in Procc. 8th International Conference on Environmental Science and Technology (CEST), Lemnos Island, Greece, 2003. pp. 557 – 564.
9. L. Vicente-Vicente et al., “Nephrotoxicity of Uranium: Pathophysiological, Diagnostic and Therapeutic Perspectives,” Toxicol. Sci., vol. 118, no. 2, pp. 324 – 347, Dec. 2010.
   DOI: 10.1093/toxsci/kfq178
   PMid: 20554698
10. Народна скупштина Републике Србије. (1999). Правилник о хигијенској исправности воде за пиће. (National Assembly of the Republic of Serbia. (1999). Regulations on the drinking water quality.)
    Retrieved from: http://demo.paragraf.rs/WebParagrafDemo/?did=1104;
    Retrieved on: Dec. 25, 2017

We report on the findings from the radon monitoring in selected points of the IRT-Sofia nuclear site, which is an important part of radiation surveillance activities during the operation and maintenance of the facilities at the Nuclear Scientific Experimental and Educational Centre (NSEEC) of the Institute for Nuclear Research and Nuclear Energy. Consideration is given to the evidence prior and during the dismantling activities related to the IRT research reactor refurbishment project and after their accomplishment.

1. Tz. Nonova, D. Stankov, Al. Mladenov, K. Krezhov, “Radiological characterization activities during the partial dismantling of the IRT - Sofia research reactor facilities,” Roman. J. Phys., vol. 59, no. 9-10, pp. 976 – 988, 2014.
   Retrieved from: http://www.nipne.ro/rjp/2014_59_9-10/0976_0988.pdf;
   Retrieved on: Nov. 24, 2017
2. I. S. Dimitrov, Tz. Nonova, Al. Mladenov, K. Krezhov, “Radiation levels at carrying out the refurbishment of the Bulgarian research reactor IRT-2000,” Radiation and Applications, vol. 1, no. 1, pp. 62 – 68, Apr. 2016.
   DOI: 10.21175/RadJ.2016.01.12
3. Al. Mladenov, D. Stankov,Tz. Nonova, K. Krezhov. “Radiation protection, radioactive waste management and site monitoring at the Nuclear Scientific Experimental and Educational Centre IRT-Sofia at INRNE – BAS,” Rad. Prot. Dosim., vol. 1, no. 1-2, pp. 176 – 181, Jul. 2014.
   DOI: 10.1093/rpd/ncu254
   PMid: 25071246
4. Al. Mladenov, Tz. Nonova, D. Dimitrov, K. Krezhov, “Radioactive Waste Management at the Nuclear Scientific and Experimental Centre of Institute for Nuclear Research and Nuclear Energy – BAS,” Radiation and Applications, vol. 1, no. 3, pp. 193 – 198, Dec. 2016.
   DOI: 10.21175/RadJ.2016.03.036
5. A. Sakoda, Y. Ishimori, K. Yamaoka, “A comprehensive review of radon emanation measurements for mineral, rock, soil, mill tailing and fly ash,” Appl. Radiat. Isotopes, vol. 69, no. 10, pp. 1422 – 1435, Oct. 2011.
   DOI: 10.1016/j.apradiso.2011.06.009
   PMid: 21742509
6. P. Bossew, “Mapping the geogenic radon potential and estimation of radon prone areas in Germany,” Radiation Emergency Medicine, vol. 4, no. 2, pp. 13 – 20, 2015.
   Retrieved from: http://crss.hirosaki-u.ac.jp/wp-content/files_mf/1465449240rem_vol42_03_peter_bossew2.pdf;
   Retrieved on: Nov. 24, 2017
7. Lung Cancer Risk from Radon and Progeny and Statement on Radon, ICRP Publication 115, ICRP, Ottawa, Canada 2010.
   DOI: 10.1016/j.icrp.2011.08.011
   PMid: 22108246
8. H. Zeeb, F. Shannoun, WHO handbook on indoor radon - a public health perspective, WHO, Geneva, Switzerland, 2009.
   Retrieved from: http://apps.who.int/iris/bitstream/10665/44149/1/9789241547673_eng.pdf;
   Retrieved on: Nov. 24, 2017
9. European Council. (Dec. 5, 2013). Council Directive 2013/59/EURATOM laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation, and repealing Directives 89/618/Euratom, 90/641/Euratom, 96/29/Euratom, 97/43/Euratom and 2003/122/Euratom.
10. Агенция за ядреного регулиране. (25.09.2012). Но. 229 Наредба за основните норми за радиациона защита. (Bulgarian Nuclear Regulatory Agency. (Sep. 9, 2012). No. 229 Regulation on Basic Norms of Radiation Protеction.)
    Retrieved from: http://www.bnra.bg/bg/documents/legislation/regulations/reg-onrz-2012.pdf;
    Retrieved on: Nov. 24, 2017
11. Measurement of radioactivity in the environment—Air, Part 4: Radon-222: integrated measurement methods for the determination of the average radon activity concentration in the atmospheric environment using passive sampling and delayed analysis, ISO 11665-1:2012, Nov. 29, 2012.
    Retrieved from: https://www.iso.org/standard/52187.html;
    Retrieved on: Nov. 24, 2017
12. K. Ivanova, Z. Stojanovska, M. Tsenova, V. Badulin, B. Kunovska, “Measurement of indoor radon concentration in kindergartens in Sofia, Bulgaria,” Rad. Prot. Dosim. vol. 162, no. 1-2, pp. 163 – 166, Nov. 2014.
    DOI: 10.1093/rpd/ncu251
13. Bulgarian Nuclear Regulatory Agency. (Sep. 2, 2004). No. 231 Regulation on Ensuring the Safety of Research Nuclear Installations.
    Retrieved from: http://www.bnra.bg/en/documents-en/legislation/regulations/reg-rr-en.pdf;
    Retrieved on: Nov. 24, 2017
14. Bulgarian Nuclear Regulatory Agency. (Aug. 24, 2004). No. 74/08.09.2006 Regulation for radiation protection during activities with sources of ionizing radiation.
    Retrieved from: http://www.bnra.bg/en/documents-en/legislation/regulations/reg-radprot-2012-en.pdf;
    Retrieved on: Nov. 25, 2017
15. Bulgarian Nuclear Regulatory Agency. (May 18, 2004). No. 41/18.05.2004 Regulation on the procedure for issuing licenses and permits for safe use of nuclear energy.
    Retrieved from: http://www.bnra.bg/en/documents-en/legislation/regulations/reg-licence-en.pdf;
    Retrieved on: Nov. 25, 2017
16. Bulgarian Nuclear Regulatory Agency. (Feb. 20, 2015). Act on the Safe Use of Nuclear Energy.
    Retrieved from: http://www.bnra.bg/en/documents-en/legislation/laws/zbiae2012-en.pdf;
    Retrieved on: Nov. 25, 2017
17. Министерство на здравеопазването. (7.11.2005). Наредба Но. 32 за условията и реда за извършване на индивидуален дозиметричен контрол на лицата, работещи с източници на йонизиращи лъчения. (Minitry of Health. (Nov. 7, 2005). Regulation № 32 on the terms and conditions for individual dosimetric control of the persons working with sources of ionizing radiation.)
    Retrieved from: http://www.mh.government.bg/media/filer_public/2015/04/22/naredba32-ot-7-11-
    2005g-individualen-dizometrichen-kontrol-ionizirashti-lachenia.doc;
    Retrieved on: Nov. 25, 2017
18. Министерство на здравеопазването. (16.9.2005). Наредба Но. 29 за здравни норми и изисквания при работа в среда на йонизиращи лъчения. (Ministry of Health. (Sep. 16, 2005). Regulation №29 on health standards and requirements at work in ambience of ionizing radiation.)
    Retrieved from: http://econ.bg/Нормативни-актове/Наредба-29-от-16-септември-2005
    -г-за-здравни-норми-и-изисквания-при-работа-в-среда-на-йонизиращи-_l.l_i.127032_at.5.html;
    Retrieved on: Nov. 25, 2017
19. Bulgarian Nuclear Regulatory Agency. (05.10.2012). Regulation on the Procedure for Issuing Licenses and Permits for Safe Use of Nuclear Energy, Promulgated in the State Gazette No. 41/18.05.2004, Amended SG No. 78/30.09.2005; 93/24.11.2009; 76/05.10.2012.
    Retrieved from: https://gnssn.iaea.org/CSN/School%20of%20Drafting%20Regulations%20Nov%20
    2014/School%20of%20drafting%20Nov%202014%20Background%20information/Participants%27%20materials/Bulgaria%20-reg-licensing-2012-en.pdf;
    Retrieved on: Nov. 25, 2017
20. Bulgarian Nuclear Regulatory Agency. (5.10.2012). Regulation for radiation protection during activities with sources of ionizing radiation, amended State Gazette No 76/5.10.2012.
    Retrieved from: http://www.bnra.bg/en/documents-en/legislation/regulations/reg-radprot-2012-en.pdf;
    Retrieved on: Nov. 25, 2017
21. Radiation Protection and Radioactive Waste Management in the Design and Operation of Research Reactors, Safety Guide No. NS-G-4.6, IAEA, Vienna, Austria, 2008.
    Retrieved from: https://www-pub.iaea.org/MTCD/publications/PDF/Pub1369_web.pdf;
    Retrieved on: Nov. 25, 2017
22. Safety considerations for research reactors in extended shutdown, IAEA-TECDOC-1387, IAEA, Vienna, Austria, 2004.
    Retrieved from: https://www-pub.iaea.org/MTCD/publications/PDF/te_1387_web.pdf;
    Retrieved on: Nov. 25, 2017
23. Environmental and Source Monitoring for Purposes of Radiation Protection, Safety Guide No. RS-G-1.8, IAEA, Vienna, Austria, 2012.
    Retrieved from: https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1216_web.pdf;
    Retrieved on: Nov. 25, 2017

We aimed to study the karyotype structure of human adult stem cells after X-ray irradiation. Cultured endometrial mesenchymal stem cells (eMSC) isolated from desquamated endometrium of menstrual blood of the healthy woman were the object of this research. The eMSC at the 9^th passage were irradiated with the sublethal X-ray dose (5Gy). Irradiated cells were cultivated under standard conditions and, at the 13^th passage, they underwent to the karyotyping assay with the G-banding technique. The cytogenetic analysis revealed that the progeny of irradiated cells exhibited genetic instability. Most of analyzed cells had chromosomal abnormalities. Karyotypic changes were manifested mostly as aneuploidy and near-centromeric and other breaks. Within a particular karyotype, various chromosomes may be involved in breaks. Chromosome 1, 4 and X were not involved in chromosomal rearrangements randomly. About 80% of the control not irradiated eMSC metaphase plates had the standard karyotype at the same 13^th passage. Deviations from the normal karyotype were random. Chromosomal breaks were not observed. Our findings show that sublethal X-ray irradiation of eMSC resulted in multiple disorders of the genetic apparatus at the karyotype level. The cells that survived irradiation entered replicative senescence and avoided immortalization or transformation.

1. Y. Kodama et al., “Stable chromosome aberrations in atomic bomb survivors: Results from 25 years of investigation.” Radiat. Res., vol. 156, no. 4, pp. 337 – 346, Jun. 2001.
   DOI: 10.1667/0033-7587(2001)156[0337:SCAIAB]2.0.CO;2
2. M. Nakano, Y. Kodama et al., “Detection of stable chromosome aberrations by FISH in A-bomb survivors: Comparison with previous solid Giemsa staining data on the same 230 individuals,” Int. J. Radiat. Biol., vol. 77, no. 9, pp. 971 – 977, Sep. 2001.
   DOI: 10.1080/09553000110050065
   PMid: 11576457
3. L. Stoilov, M. Georgieva, V. Manova, L. Liu, K. Gecheff, “Karyotype reconstruction modulates the sensitivity of barley genome to radiation-induced DNA and chromosomal damage,” Mutagenesis, vol. 28, no. 2, pp. 153 – 160, Mar. 2013.
   DOI: 10.1093/mutage/ges065
   PMid: 23221036
4. K. Ohtaki et al., “Human fetuses do not register chromosome damage inflicted by radiation exposure in lymphoid precursor cells except for a small but significant effect at low doses,” Radiat. Res., vol. 161, no. 4, no. 373 – 379, Apr. 2004.
   DOI: 10.1667/3147
5. B. Ponnaiya et al.,“The evolution of chromosomal instability in Chinese hamster cells: a changing picture?” Int. J. Radiat. Biol., vol. 74, no. 6, pp. 765 – 770, Dec. 1998.
   DOI: 10.1080/095530098141041
   PMid: 9881722
6. K. Suzuki, R. Takahara, S. Kodama, M. Watanabe, “In situ detection of chromosome bridge formation and delayed reproductive death in normal human embryonic cells surviving X irradiation,” Radiat. Res., vol. 150, no. 4, pp. 375 – 381, Oct. 1998.
   DOI: 10.2307/3579655
   PMid: 9768850
7. S. Salomaa, K. Holmberg, C. Lindholm, R. Mustonen, M. Tekkel, T. Veidebaum, B. Lambert, “Chromosomal instability in in vitro radiation exposed subjects,” Int. J. Radiat. Biol., vol. 74, no. 6, pp. 771 – 779, 1998.
   DOI: 10.1080/095530098141050
   PMid: 9881723
8. И. К. Хвостунов и др., “Анализ хромосомных аберраций в клетках млекопитающих при воздействии различных видов ионизирующего излучения,” Радиация и риск, т. 22, но. 4, стр. 43 – 59, 2013. (I. K. Khvostunov et al., “Analysis of chromosome aberrations in mammalian cells under the action of various types of ionizing radiation,” Radiation and Risk, vol. 22, no. 4, pp. 43 – 59, 2013.)
   Retrieved from: http://radiation-and-risk.com/images/pdf/rr_13_4_8.pdf;
   Retrieved on: Jan. 26, 2018
9. Н. Л. Шмакова, Е. А. Насонова, Е. А. Красавин, Л. А. Мельникова, Т. А. Фадеева, “Индукция хромосомных аберраций и микроядер в лимфоцитах периферической крови человека при действии малых доз облучения,” Радиационная биология. Радиоэкология, т. 46, но. 4, стр. 480 – 487, 2006. (N. L. Shmakova, E. A. Nasonova, E. A. Krasavin, L. A. Melnikova, T. A. Fadeeva, “The induction of chromosome aberrations and micronuclei in human peripheral blood lymphocytes at low doses of radiation,” Radi. Radioecology, vol. 48, no. 4, pp. 480 – 487, 2006.)
10. Ю. Н. Шишмарев и др., “Клинические аспекты последствий аварии на Чернобыльской АЭС,” Радиобиология, т. 32, но. 3, стр. 323 – 332, 1992. (Yu. N. Shishmarev et al., “Clinical Aspects of the Consequences of the Chernobyl Accident,” Radiobiology, vol. 32, no. 3, pp. 323 – 332, 1992.)
11. S. Knehr, H. Zitzelsberger, H. Braselmann, U. Nahrstedt, M. Bauchinger, “Chromosome analysis by fluorescence in situ hybridisation: further indications for a non-DNA-proportional involvement of single chromosomes in radiation-induced structural aberrations,” Int. J. Radiat. Biol., vol. 70, no. 4, pp. 385 – 392, Oct. 1996.
    DOI: 10.1080/095530096144851
    PMid: 8862449
12. J. J. W. A. Boei, S. Vermeulen, A. T. Natarajan, “Different involvement of chromosomes 1 and 4 in the formation of chromosomal aberrations in human lymphocytes after X-irradiation,” Int. J. Radiat. Biol., vol. 72, no. 2, pp. 139 – 145, Aug. 1997.
    DOI: 10.1080/095530097143356
    PMid: 9269306
13. G. Stephan, S. Pressl, “Chromosome aberrations in human lymphocytes analysed by fluorescence in situ hybridisation after in vivo irradiation, and in radiation workers, 11 years after an accidental radiation exposure,” Int. J. Radiat. Biol., vol. 71, no. 3, pp. 293 – 299, Mar. 1997.
    DOI: 10.1080/095530097144175
    PMid: 9134019
14. А. Н. Богомазова, “Изучение стабильных и нестабильных хромосомных аберраций у лиц, пострадавших в результате аварии на ЧАЭС, в отдаленный пострадиационный период,” Дисс. канд. биол. наук, Центральный научно-исследовательский рентгенорадиологический институт, Санкт-Петербург, Россия, 2000. (A. N. Bogomazova, “The study of stable and unstable chromosomal aberrations in persons affected by the Chernobyl accident in the remote post-radiation period,” Cand. Sc. dissertation, Central Research Institute of Radiology, St-Petersburg, Russia, 2000.)
15. V. I. Zemelko et al.,“Multipotent mesenchymal stem cells of desquamated endometrium: isolation, characterization and use as feeder layer for maintenance of human embryonic stem cell lines,” Tsitologija, vol. 53, no. 12, pp. 919 – 929, 2011.
    DOI: 10.1134/S1990519X12010129
    PMid: 22359950
16. ISCN 1995 An International System for Human Cytogenetic Nomenclature, Recommendations of the ISCN, ISCN, Basel, Switzerland, 1995.
17. С. Е. Мамаева, Атлас хромосом постоянных клеточных линий человека и животных, Москва, Россия: Научный Мир, 2002. (S. E. Mamaeva, Atlas chromosomes permanent cell lines of human and animals, Moscow, Russia: Sci. World, 2002.)
18. М. А. Шилина, “Физиологическая и генетическая характеристика эндометриальных мезенхимных стволовых клеток человека в культуре,” дисс. канд. биол. наук., Институт цитологии Российской академии наук, Санкт-Петербург, Россия, 2017. (M.A. Shilina, “Physiological and genetic characteristic of human endometrial mesenchymal stem cells in culture,” Cand. Sc. Dissertation, Institute of Cytology of the Russian Academy of Sciences, St-Petersburg, Russia, 2017.)
    Retrieved form: http://docplayer.ru/71738775-Shilina-mariya-aleksandrovna-fiziologicheskaya-i-geneticheskaya-harakteristika-endometrialnyh-mezenhimnyh-stvolovyh-kletok-cheloveka-v-kulture.html;
    Retrieved on: Jan. 25, 2018