Al-Tuwaitha Nuclear Site Research Articles

Soil Measurements Using High Purity Germanium Gamma Spectroscopy for Areas Surrounding Al-Tuwaitha Nuclear Site

This study introduces the calculations of the radiation background, by characterizing the radionuclides and calculating their specific effectiveness in the environment of the city of Baghdad (soil and plants) using the gamma-ray spectroscopy technique. 20 soil samples at a depth of 20 cm were collected for 5 locations on the Rusafa side, where the site coordinates were fixed using the G.P.S device. A modern global gamma-ray spectroscopy system (DSA 2000) was used, with high-purity germanium (HPGe) detector with an efficiency of 50% and an analysis capacity of 2.2 keV with respect to the energy of 1332 keV for the 60Co source. The results of the specific activity rates of the radionuclides (214Bi or 214Pb), (228Ac or 208Tl), (40K), and (137Cs) in soil were: (50.735 Bq/kg or 0.525 Bq/kg) which is close to the value of the previously published results, as the highest value was recorded in Bangladesh (88.1 Bq/kg or 4.8 Bq/kg). The results of the qualitative effectiveness of the soil of the sites showed normal levels within the radiation background of Baghdad's soil. There was a significant convergence of the study's findings with other studies.

Measurement of Radioactive Concentrations and Determination of Isotopes Using Portable Devices for Radiochemistry Laboratories Al-Tuwaitha Nuclear Site in Iraq

The measurements of radioactive concentrations using portable radiological devices for radiochemistry laboratories at the Al-Tuwaitha nuclear site (section C) were studied, section C consists of three laboratories, C1, C2, and C3 were used, Redeye device to measure the radioactive concentrations of alpha and beta emitters, and the Interceptor™ Specifications device to detect radioisotopes. The results showed the presence of radioactive contamination in Unit C distributed over most of its parts. In the C1 laboratory, the highest radioactive contamination was recorded in HCL2 with a concentration of 113.65Bq/cm2. In addition, the C2 laboratory recorded the highest radioactive concentration in FH1 with a concentration of 830.14Bq/cm2 for Beta particle emitters, while the C3 laboratory recorded the highest pollution in FH contamination with a radioactive concentration of 75.26 Bq/cm2. The results show that location C shows the isotopes detected in the laboratory components, such as Cesium 137Cs, Neptunium 237Np, and Americium 241Am. The results showed the presence of contamination on the laboratory floor in the fourth part, contaminated with Americium 241Am and Lutetium 167Lu isotopes. While location B did not record radioactive contamination in most of its parts except for room B8 which recorded radioactive concentrations of about 1.33 Bq/cm2. While location A, that is, no radioactive contamination was recorded, and the readings were within the permissible limits

Field Radiological Characterization for Scrap Yards at Al-Tuwaitha Nuclear Site

In the present study, measurements of alpha/beta contamination and gamma dose rates measurements were carried out in scrap yard contaminated by spillage of sludge contained 238U at Al-Tuwaitha Nuclear Site. Alpha/beta surface soil contamination levels were directly measured in the field at January 2016 using RadEye SX monitor. Gamma dose rates measurements were conducted using RadEye PRD. The results showed that alpha/beta surface soil contamination levels varied from 0.1 for uncontaminated areas and reach 2.8 Bq/cm2 for contaminated areas, with an average value of 0.8 Bq/cm2, which is more than 6 times the local natural background level. Results of dose assessment indicate that, the potential radiation doses to on-site workers from site contaminants were estimated to be in the order of 0.036 mSv/y, which was considered within the occupational dose limit of 20 mSv/y recommended in the International Atomic Energy Agency (IAEA) GSR Part 3 (2014). However, the mean dose rate reaches 4.5 times the background level, indicating that remediation of site contaminants is recommended to ensure environmental safety.

Searching for Abandoned Radioactive Sources in Scrap Yards at Al-Tuwaitha Nuclear Site

In the present study, the scrap yards (located within the latitudes 33o 21’ 613” to 33o 21’ 290” North, and longitudes 44o 51’ 299” to 44o 50’ 904” East) at Al-Tuwaitha nuclear site were scanned for the period from January to February 2016 using hand-held radiation detectors with the intent of locating radioactive sources thrown within piles of scrap material. Only one 137Cs radioactive source has been found with an estimated activity of 6.3×108 Bq, which was found to be considerably less than the “dangerous quantity” D-value of 1×1011 Bq. Assessment of the potential radiological consequences arising from exposure to the source during normal conditions has been conducted using Rad Pro Calculator Version 3.26 (2009). The potential radiological dose arising from normal occupational exposure situation was estimated to be 139 mSv/y at 1 meter distance from the source, which was considerably higher than the occupational dose limit of 20 mSv/y recommended in the International Atomic Energy Agency (IAEA) GSR Part 3 (2014), indicating that this source must be removed and treated as radioactive waste.

Detecting the relations between meteorological elements and alpha and beta activity concentration at Al-Tuwaitha site, Baghdad

In this study, 50 samples of air particulates collected from different places in- and outside the Al-Tuwaitha nuclear site, south of Baghdad were used to measure daily gross alpha and beta activity concentrations (AAC and BAC) for the period from 28 January 2015 to 13 April 2017. At the same time, several meteorological factors such as air temperature, wind speed, wind direction, air pressure, relative humidity, and solar radiation, were also measured. Air stability classes were also derived from wind speed and solar radiation. AAC/BAC variations in the surface air layer were discussed in relation to these factors. The results show that there are inverse relations between AAC/BAC and wind speed and temperature, linear relations between AAC/ABC and air pressure and weak relations between AAC/BAC and relative humidity and solar radiation. Lastly, AAC/BAC measurements in unstable air are as large as in neutral air.

Using Dates Leaves Midribs to Prepare Hierarchical Structures Incorporating Porous Carbon and Zeolite A Composites for Cesium137Cs Ion Exchange

This study synthesized zeolite 4A, and hierarchical composite structure consisting of zeolite 4A- carbon were successfully prepared. Hydrothermal method was used to grow a layer of zeolite 4A over porous carbon surfaces to enhance mass transfer and increase surface area of zeolite. The products then were used to remove radioactive cesium137Cs from liquid wastewater. Iraqi dates leaves midribs (DM) were used as locally available agricultural waste to prepare low- cost porous carbon, using carbonization method in tubular furnace at 900C for two hours. Hierarchical porous structures including zeolite are prepared by mechanically activating the carbon surface via Ultrasonicating nanoparticles suspension of ground zeolite type 4A.For preparing nanoparticles suspension, commercial zeolite has been milled using 0.3-0.4 mm diameter glass balls as grinding media. Nanoparticles of zeolite 4A acting as seeding (nucleation centers) increase the crystallization of amorphous aluminosilica gel on modification carbon surface. The products of the syntheses zeolite 4A and the hierarchal composite materials (DMZ) were characterized using Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Nitrogen sorption (BET) and Energy dispersive X-ray spectrometer (EDX) to check the morphology, structure, surface area, and the chemical composition respectively. The products were used to treat radioactive wastewater contaminated with radioactive cesium 137Cs collected from destroyed building of the Radiochemistry Laboratories (RCL) in AL-Tuwaitha Nuclear Site. The activity concentration for the contamination water pre and after the treatment were measured using gamma spectroscopy system supplied with a high purity germanium detector (HPGe) with 60% relative efficiency. The results showed that the radioactivity concentration after the treatment process decreased significantly from 4800 Bq/L to 186 and Bq/L,121 Bq/L using 0.045 gm from synthesized zeolite 4A and DMZ respectively.

Hierarchical Structures Incorporating Carbon and Zeolite to Remove Radioactive Contamination

Synthesis, characterization and application of hierarchical zeolites are becoming a subject of an increasing interest among scientists and researchers. Hierarchical structures incorporating zeolites possess secondary porosity at meso- and macrolevel to overcome problem of mass transport, which occurs with using conventional zeolites.
 In this study, the porous carbon surface was prepared by carbonization of the locally available agricultural waste of the Iraqi Nut shell (NS) using a carbonization method in a tubular furnace at 900ËšC for two hours. Hierarchicalpours structures including zeolite were prepared by the mechanical activation of the carbon surface using ultrasonication with a nanoparticles suspension of ground commercial zeolite type 4A. Zeolite was milled using 0.3-0.4 mm diameter glass balls as grinding media to prepare nanoparticles seeding, which increases the crystallization of the amorphous aluminosilica gel on the modified carbon surface during the hydrothermal method. The Product of the syntheses of zeolite 4A and the hierarchal composite material were characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Nitrogen-Adsorption /desorption isotherms (BET), Energy Dispersive Spectroscopy (EDX), and Thermo Gravimetric Analysis (TGA) to determine the structure, morphology, surface area, chemical composition, and percentage weight of zeolite on carbon, respectively. The products were applied to remove the radioactive hazardous cesium isotope Cs137 from the radioactive wastewater provided by the destroyed building of Radiochemistry laboratories (RCL) in AL-Tuwaitha Nuclear Site. Gamma spectroscopy system with high purity germanium detector (HPGe) was used to measure the activity concentration for the contamination water before and after the treatment. The results showed that the activity concentration decreased from 4800 Bq/L to 186Bq/L and 100Bq/L using pure zeolite 4A and NSZ.respectively. The results also showed that the composite materials could be used effectively to remove radioactive 137Cs from a real wastewater, with ease of separation and recovery from the solution compared with the pure zeolite 4A.

Ionizing Radiation Effect and DNA damage in the workers of Al-Tuwaitha Nuclear Site

Single cell gel electrophoresis (SCGE), also called comet assay, is a rapid and sensitive technique used to analyse DNA Fragmentation Index(DFI). This study aimed to evaluate DNA damage in lymphocytes due to ionizing radiation in workers of Al-Tuwaitha nuclear site, which has been used for nuclear activities and contains a potentially significant amount of radioactive waste.The workers in this site are vulnerable to pollution due to a highly polluted environment of ionizing radiation. Blood samples were collected from 36 workerswho were divided into two groups;8 workers without protection and 28workers with protection, in addition to 30 control subjects.Alkaline comet assay was applied for analysis and the results indicated significantly higher DNA damage in the workers without protection as compared with the workers with protection and control groups.The result also showed significant differences between the workers with protection and control groups.

Measurement of uranium concentration in the water samples collected from the areas surrounding in Al-Tuwaitha nuclear site using the CR-39 detector

In this research, the uranium concentration in (16) water samples collected from some agricultural areas surrounded with AlTuwitha nuclear site in Baghdad-Iraq was measured by using a CR-39 detector. The concentration of uranium in this study was from (0.6 ± 0.33mg/l) to (2.51 ± 0.49 mg/l), and the weighted average for the concentrations (1.262 ± 0.402 mg/l). The results showed it is a concentration of uranium level in water samples studied is higher than the allowed limit recommended by WHO and ICRP.

Measurement of indoor radon levels and assessment of radiological hazards at Al-Tuwaitha nuclear site and the surrounding area

In the present study the radon concentration was measured in indoor places by the RAD7 (radon detector) was in some locations at Al-Tuwaitha nuclear site and some surrounding areas for the duration from 13/10/2016 to 2/1/2017 and the measurement of the indoor radon concentration ranged from (4.96±4.4 to 102±25) Bq/m3. The high value of radon has been found at decommissioning directorate /emergency room, which is lower than the action value recommended by the Environmental Protection Agency (EPA) which is (148 Bq/m3) while the lowest value has been founded in central laboratories directorate \ models room. These values were used to calculate the annual effective dose and the health risks for cells bronchial which caused by the inhalation of radon. The values of the annual effective doses were calculated and ranged from (0.1249 to 2.5704) mSv/y these results are lower than the value of (10 mSv/y) recommended by the International Commission Radiological on Protection (ICRP). The results from this study shows that the region has background radioactivity levels within the natural limits.

Assessment of Radiological Air Contamination for Selected Places at Al-Tuwaitha Nuclear Site during Winter and Spring

This study presents the results of atmospheric particulates sampling using high volume air sampler for selected places at Al Tuwaitha nuclear site. The collected samples were analyzed for gross alpha /beta radioactivity using Ludlum model 3030 and measurement particles activity in Al Tuwaitha nuclear site and the surrounding areas for the period from 28/12/2016 to 13/4/2017.The measurement of activity concentrations ranged from (0.42±0.03 to 4.18±0.13) Bq/m3 for alpha particles and from(0.93±0.06 to 9.21±0.26) Bq/m3for beta particles. The activity concentration of nuclides inversely proportional with air temperature and wind speed while humidity is directly proportional with it. Highest value of activity concentration has been found at(Near nuclear and radiation safety directorate/ In the center of planning department/T9)while the lowest value has been found at (the right side of Nuclear application and researches directorate / building 61/T42). The results of this study show that the region has natural nuclides which are the daughters of the two decay series, namely the thorium and the uranium series. In both cases, it is a radioactive Radon isotope which can escape from the soil and ascend into the air.

Estimation the annual dose for residents in the area around the berms of Al-Tuwaitha nuclear site using RESRAD software

RESRAD is a computer model designed to estimate risks and radiation doses from residual radioactive materials in soil. Thirty seven soil samples were collected from the area around the berms of Al-Tuwaitha site and two samples as background taken from an area about 3 km north of the site. The samples were measured by gamma-ray spectrometry system using high purity germanium (HPGe) detector. The results of samples measurements showed that three contaminated area with 238U and 235U found in the study area. Two scenarios were applied for each contaminated area to estimate the dose using RESRAD (onsite) version 7.0 code. The total dose of resident farmer scenario for area A, B and C are 0.854, 0.033 and 2.15×10-3 mSv.yr-1, respectively. While suburban resident scenario for area A, B and C are 0.807, 0.031 and 2.04×10-3 mSv.yr-1, respectively.

Using SAFRAN Software to Assess Radiological Hazards from Dismantling of Tammuz-2 Reactor Core at Al-tuwaitha Nuclear Site

The Safety Assessment Framework (SAFRAN) software has implemented here for radiological safety analysis; to verify that the dose acceptance criteria and safety goals are met with a high degree of confidence for dismantling of Tammuz-2 reactor core at Al-tuwaitha nuclear site. The activities characterizing, dismantling and packaging were practiced to manage the generated radioactive waste. Dose to the worker was considered an endpoint-scenario while dose to the public has neglected due to that Tammuz-2 facility is located in a restricted zone and 30m berm surrounded Al-tuwaitha site. Safety assessment for dismantling worker endpoint-scenario based on maximum external dose at component position level in the reactor pool and internal dose via airborne activity while, for characterizing and packaging worker endpoints scenarios have been done via external dose only because no evidence for airborne radioactivity hazards outside the reactor pool. The in-situ measurements approved that reactor core components are radiologically activated by Co-60 radioisotope. SAFRAN results showed that the maximum received dose for workers are (1.85, 0.64 and 1.3mSv/y) for activities dismantling, characterizing and packaging of reactor core components respectively. Hence, the radiological hazards remain below the low level hazard and within the acceptable annual dose for workers in radiation field

Assessment of Natural Radioactivity Levels and Radiation Hazards of Scrap Yard Soil Samples at Al-Tuwaitha Nuclear Site (Iraq)

Assessment of Natural Radioactivity Levels and Radiation Hazards of Scrap Yard Soil Samples at Al-Tuwaitha Nuclear Site (Iraq)

Measurement of Radioactivity Levels and Assessment of Radiation Hazards for Plants Species Grown at Scrap Yard (B) at Al-Tuwaitha Nuclear Site (Iraq)

Samples of flowered grasses, herbs and jungles were collected from scrap yard (B) at Al-Tuwaitha Nuclear Site and analyzed in the laboratory using gamma-ray spectroscopy system. The activity concentrations for radionuclides grown on the studied area were found to be ranged from 1.05 to 5.45 Bq/kg (average 2.86 Bq/kg) for 226Ra, below detection limit (BDL) to 1.4 Bq/kg (average 0.16 Bq/kg) for 232Th, 483.2 to 595.7 Bq/kg (average 528.33 Bq/kg) for 40K, and BDL to 1.15 Bq/kg (average 0.35 Bq/kg) for 235U. No radionuclides of artificial origin (such as 137Cs) were detected in any of the analyzed samples. Gamma absorbed dose rates (D), radium equivalent activities (Raeq), external hazard index (Hex), and internal hazard index (Hin) were calculated and found to be considerably lower than their corresponding allowable limits and worldwide average values. Accordingly, it was found that natural radioactivity levels for the investigated plants species grown at the studied area pose no significant radiological threat to human health or the environment.

Assessment of Radiological Air Contamination for Selected Places at Al-Tuwaitha Nuclear Site during Winter and Spring

This study presents the results of atmospheric particulates sampling using high volume air sampler for selected places at Al Tuwaitha nuclear site. The collected samples were analyzed for gross alpha /beta radioactivity using Ludlum model 3030 and measurement particles activity in Al Tuwaitha nuclear site and the surrounding areas for the period from 28/12/2016 to 13/4/2017.The measurement of activity concentrations ranged from (0.42±0.03 to 4.18±0.13) Bq/m3 for alpha particles and from(0.93±0.06 to 9.21±0.26) Bq/m3for beta particles. The activity concentration of nuclides inversely proportional with air temperature and wind speed while humidity is directly proportional with it. Highest value of activity concentration has been found at(Near nuclear and radiation safety directorate/ In the center of planning department/T9)while the lowest value has been found at (the right side of Nuclear application and researches directorate / building 61/T42). The results of this study show that the region has natural nuclides which are the daughters of the two decay series, namely the thorium and the uranium series. In both cases, it is a radioactive Radon isotope which can escape from the soil and ascend into the air.

Measurement of Radon Activity in Soil Gas and the Geogenic Radon Potential Mapping Using RAD7 at Al-Tuwaitha Nuclear Site and the Surrounding Areas

In this study Soil gas radon ²²²Rn activity was measured in different locations at Al-Tuwaitha Nuclear Site and the surrounding areas using RAD7 (radon detector). Radon activity in the soil gas varied from (866±150 to 16004±521) Bq/m³ near Alaibtihal School and Ishtar \ Al-Ttakhi School respectively. These concentrations values are well below the allowed levels that range from (0.4 to 40) KBq/m³. The annual effective doses related to the inhalation of radon gas and its progeny which were calculated from the Concentration of emanation in air near ground ranged from (0.0082305 to 0.152102) mSv/y. these results are less than the recommended global average dose from the inhalation of radon from all sources, which is 1 mSv/y. The Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radon potential (GRP), The highest values were found in Ishtar \ Al-Ttakhi school which is (16.004) and The lowest values were found Near Alaibtihal school which is (0.288666667), the lowest value according to Neznal was classified as low (GRP < 10) and the highest value was classified as medium (10 < GRP < 35), according to Barnet and Pacherová low GRP causes <230 Bq m^-3 while medium GRP causes 230-460 Bq m^-3 indoor radon concentration. From these different values of GRP a geogenic radon risk map was created, which assists human health risk assessment and risk reduction since it indicates the potential of the source of indoor radon. The results from this study shows that the region has background radioactivity levels within the natural limits.

Assessment of Radioactivity Levels for the Fuel Fabrication Facility at Al-tuwaitha Nuclear Site (Iraq)

The activity concentrations of twenty soil samples collected from contaminated locations of Fuel Fabrication Facility (FFF) at Al- Tuwaitha nuclear site, Iraq, were determined by using spectroscopy with a high purity germanium detector. The range of activity concentrations of 238U (234mPa), 235U, 232Th (228Ac), and 40K in the soil from the studied areas varies from (177.74±60) to (375777.5±6895) Bqkg-1, (7.4±0.5) to (20954±407.5) Bqkg-1, (7.06±0.22) to (20.45±0.33) Bqkg1 and from (47.5±5.3) to (402.2±15.5) Bq kg-1 respectively. The isotopic mass and activity ratio of 235U/238U were calculated to identify kind of uranium, depleted or natural. To assess the radio logical risk for this site, RESRAD program was used to calculate total dose from all pathways (external, inhalation and soil ingestion) of exposure, the value of total dose was 2mSv/yr. Laboratory results indicated that the FFF was contaminated with 234mPa and 235U nuclides in excess of the IAEA limits for exemption from regulatory control, and indicating that the decommissioning operations for the FFF must be subjected to regulatory control and safety surveillance to ensure adequate protection of the operators, public and the environment.

The Estimation of Dose Relationships for the Inhalation of Radon and the Difference in Activities During the Year Using RAD7 in Iraq

Exposure to radon and its daughters is one of the important contributions for radiation doses to the publics. In this study, concentrations of radon gas were measured in air at Al-Tuwaitha Nuclear Site and some surrounding areas. Measurements were achieved by RAD7 (radon detector), manufactured by DURRIDGE COMPANY Inc. Indoor radon concentration plays a vital role in the total effective dose in the indoor environments. The measurement of the indoor radon concentrations ranged from (4.96±4.4 to 102±25) Bq/m 3 this high value of radon has been found at Decommissioning Directorate /emergency room, which is lower than the action value recommended by the EPA (Environmental Protection Agency) which is (148 Bq/m 3 ) while the lowest value has been founded in the Central Laboratories Directorate models Room. These values were used to calculate the annual effective dose, the dose exposed to the soft tissues other than the lungs D soft tissue , the dose rate due to alpha-radiation D lung and the effective dose equivalent rate H eff . The values of the annual effective doses for 222 Rn inhalation by the people were calculated and ranged from (0.124992 to 2.5704) mSv/y these result are lower than the value of (10 mSv/y) recommended by the ICRP (International Commission on Radiological Protection). It has been observed that winter concentration of indoor radon are greater than summer concentrations. The higher amount in the winter is attributed to the observation that people normally keep their windows closed during the winter, allowing indoor radon concentrations to rise. The lower radon concentrations in the summer might occur because people often open their windows, allowing low-radon outside air to enter the home. The results from this study show that the region has background radioactivity levels within the natural limits.

Natural Radioactivity and Associated Dose Rates in Soil Samples in the Destroyed Fuel Fabrication Facility, Iraq

The activity concentrations of naturally occurring radionuclides 226Ra, 232Th and 40K in soil samples collected from Fuel Fabrication Facility in Al-Tuwaitha nuclear site were measured by using a high resolution gamma spectrometry system via High Purity Germanium (HPGe) Detector with a relative efficiency of (>40%) and resolution (<1.8keV) at energy of (1.33MeV) for 60Co. The average activity concentrations of 226Ra, 232Th and 40K in soil samples were found to be 15.78±1.16, 14.09±1.33 and 306.42±18.1 Bqkg-1, respectively. The results obtained for the corresponding radionuclides are lower than the worldwide average values of 35, 30, and 400 Bqkg-1, respectively. The average absorbed dose rate in air (Dγ), the average radium equivalent activity (Raeq) and the average external hazard index (Hex) were determined as 28.90±2.12 nGyh-1, 59.52±4.45 Bqkg-1 and 0.16±0.012, respectively, which are below the permissible limit.