Determination of Natural Radioactivity in the United Arab Emirates

Natural radioactivity is a common constituent of all environmental matrices: Geosphere,

Hydrosphere and Biosphere. It was either primordially or cosmogenically produced. During

their lifetime, human beings can be exposed to environmental radioactivity in several ways.

Therefore, it is important to track the source and origin of the nuclear activities; either natural

or other declared/undeclared activities (e.g., nuclear power plant operation).

United Arab Emirates has proven its determination to move forward with its nuclear policy

commitments through several steps, the most important of which are the adoption of

international instruments related to nuclear safety and security and the non-proliferation of

nuclear weapons, as well as the adoption of the establishment of a legal and governmental

framework within the state, and it shows its determination through continuous support for

the development of the UAE Peaceful Nuclear Energy program.

In the framework of the ambitious peaceful nuclear program of the United Arab Emirates

(UAE), this work was launched to draw a pre-operational baseline reference natural and

artificial radioactivity image and map.

The International Atomic Energy Authority (IAEA) and the United Nations Scientific

Committee on the Effects of Atomic Radiation (UNSCEAR) documents were considered the

backbone of this work. A comprehensive regional and worldwide literature survey was

summarised and presented in a separate chapter.

In the field, four wheeled drive vans, aircrafts and boats were used to reach the sites to be

monitored. The area of study was divided into four major regions. Abu Dhabi Emirate,

Dubai and Northern Emirates and Islands in the Arabian Gulf. 79 soil, sediment, and water

samples were collected using the specific planned sampling mechanism.

An advanced γ-spectrometer; High Purity Germanium (HPGe) with its electronics and

software, was used to identify and quantify radionuclides and their radioactivity. The system

was energy and efficiency calibrated using standard 137Cs, 60Co and 226Ra Check Sources.

For the collected samples, the chemical and physical properties were determined;

mechanical and x-ray diffraction analysis were also carried out. The specific activities of

natural 238U, (226Ra) were calculated and found in soil samples to be in the range (from 1.24

± 0.16 to 55.05 ± 2.75 Bq/kg), in shore sediments samples to be in the range (from 0.63 ±

0.03 to 67.60 ± 3.38 Bq/kg). The specific activities of natural 232Th were calculated and

found in soil samples to be in the range (from 0.57 ± 0.02 to 16.44 ± 0.82 Bq/kg), in shore

sediments samples to be in the range (from 0.46 ± 0.02 to 27.5 ± 1.35 Bq/kg). The specific

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activities of natural 40K were calculated and found in soil samples to be in the range (from

4.85 ± 0.24 to 531.08 ± 26.5 Bq/kg), in shore sediments samples to be in the range (from

0.58 ± 0.02 to 528.76 ± 26.43 Bq/kg), in Gulf water samples to be in the range (from 3.19 ±

0.15 to 17.36 ± 0.86 Bq/L)

The specific activities of anthropogenic fall-out 137Cs were calculated and found in soil

samples to be in the range (from 0.04 ± 0.01 to 7.00 ± 0.35 Bq/kg), in shore sediments

samples to be in the range (from 0.02 ± 0.01 to 3.26 ± 0.16 Bq/kg). The hazard indices,

radium equivalent, annual effective dose, external hazard index, γ- and α-index, were also

estimated and evaluated.

The measured specific activities of 238U (226Ra), 232Th, 40K and 137Cs are presented in figures

and tables. The correlations and 3D figures with comparison with the mean worldwide

values are also presented. It was clearly observed that the obtained activity and hazard

indices are within the reference recommended values and limits.

Finally, the results of this thesis will also be used as a radiological and environmental safety

signature for monitoring operation of the first peaceful nuclear power plant in the UAE.