SUDOQU, a new dose-assessment methodology for radiological surface contamination.

A new methodology has been developed for the assessment of the annual effective dose resulting from removable and fixed radiological surface contamination. It is entitled SUDOQU (SUrface DOse QUantification) and it can for instance be used to derive criteria for surface contamination related to the import of non-food consumer goods, containers and conveyances, e.g., limiting values and operational screening levels. SUDOQU imposes mass (activity)-balance equations based on radioactive decay, removal and deposition processes in indoor and outdoor environments. This leads to time-dependent contamination levels that may be of particular importance in exposure scenarios dealing with one or a few contaminated items only (usually public exposure scenarios, therefore referred to as the 'consumer' model). Exposure scenarios with a continuous flow of freshly contaminated goods also fall within the scope of the methodology (typically occupational exposure scenarios, thus referred to as the 'worker model'). In this paper we describe SUDOQU, its applications, and its current limitations. First, we delineate the contamination issue, present the assumptions and explain the concepts. We describe the relevant removal, transfer, and deposition processes, and derive equations for the time evolution of the radiological surface-, air- and skin-contamination levels. These are then input for the subsequent evaluation of the annual effective dose with possible contributions from external gamma radiation, inhalation, secondary ingestion (indirect, from hand to mouth), skin contamination, direct ingestion and skin-contact exposure. The limiting effective surface dose is introduced for issues involving the conservatism of dose calculations. SUDOQU can be used by radiation-protection scientists/experts and policy makers in the field of e.g. emergency preparedness, trade and transport, exemption and clearance, waste management, and nuclear facilities. Several practical examples are worked out demonstrating the potential applications of the methodology.

Bioaccessibility of Fukushima-Accident-Derived Cs in Soils and the Contribution of Soil Ingestion to Radiation Doses in Children.

Ingestion of contaminated soil is one potential internal exposure pathway in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Doses from this pathway can be overestimated if the availability of radioactive nuclides in soils for the gastrointestinal tract is not considered. The concept of bioaccessibility has been adopted to evaluate this availability based on in vitro tests. This study evaluated the bioaccessibility of radioactive cesium from soils via the physiologically-based extraction test (PBET) and the extractability of those via an extraction test with 1 mol/L of hydrochloric acid (HCl). The bioaccessibility obtained in the PBET was 5.3% ± 1%, and the extractability in the tests with HCl was 16% ± 3%. The bioaccessibility was strongly correlated with the extractability. This result indicates the possibility that the extractability in HCl can be used as a good predictor of the bioaccessibility with PBET. In addition, we assessed the doses to children from the ingestion of soil via hand-to-mouth activity based on our PBET results using a probabilistic approach considering the spatial distribution of radioactive cesium in Date City in Fukushima Prefecture and the interindividual differences in the surveyed amounts of soil ingestion in Japan. The results of this assessment indicate that even if children were to routinely ingest a large amount of soil with relatively high contamination, the radiation doses from this pathway are negligible compared with doses from external exposure owing to deposited radionuclides in Fukushima Prefecture.

In-field evaluation of the impact of ageing and fading effects on annual radon concentration measurements for two different techniques.

Measurements covering a 1 year period are often used and required by legislation to assess the average radon concentration within a house or a workplace. This kind of long-term measurement-generally carried out with techniques based on nuclear track detectors-can be affected by a reduction in sensitivity due to ageing and fading of latent tracks during the exposure period, thus resulting in an underestimation of the actual average concentration. In order to evaluate in field conditions the ageing and fading effects on annual radon concentration measurements, two different studies in a large sample of rooms in dwellings (162) and in workplaces (432) were conducted using two different techniques (detector and track read-out system): (i) CR-39 plastics readout with a fully automated image analysis system, and (ii) LR 115 films with a spark-counter for track counting. Study design and data analysis aimed to evaluate both the average and the variability of ageing and fading effects in real conditions, and to reduce and separate the contribution of measurement uncertainty to the observed variability. For the CR-39 based technique, the results show that radon concentration measurements over a 12month period are on average about 16% lower than those evaluated with measurements of two consecutive 6 month periods, implying the need for a correction factor to avoid measurement bias (i.e. underestimation) due to ageing and fading effects. The observed variability of ageing and fading effects among the sampled rooms is not negligible (coefficient of variation about 18%), although a considerable fraction is attributable to measurement uncertainty, which is presumably not related to ageing and fading. For the technique based on LR 115 spark counting, ageing and fading do not significantly affect the results of radon concentration measurement.

EPR pilot study on the population of Stepnogorsk city living in the vicinity of a uranium processing plant.

The aim of this pilot study was to evaluate possible doses in teeth received by workers of a uranium processing plant, in excess to the natural background dose. For this, the electron paramagnetic resonance dosimetry method was applied. Absorbed doses in teeth from the workers were compared with those measured in teeth from the Stepnogorsk city population and a control pool population from Astana city. The measured tooth samples were extracted according to medical indications. In total, 32 tooth enamel samples were analyzed, 5 from Astana city, Kazakhstan (control population), 21 from the residents of Stepnogorsk city (180 km from Astana city), and 6 from the workers of a uranium processing plant. The estimated doses in tooth enamel from the uranium processing plant workers were not significantly different to those measured in enamel from the control population. In teeth from the workers, the maximum dose in excess to background dose was 33 mGy. In two teeth from residents of Stepnogorsk city, however, somewhat larger doses were measured. The results of this pilot study encourage further investigations in an effort to receiving a final conclusion on the exposure situation of the uranium processing plant workers and the residents of Stepnogorsk city.

[Retrospective Cytogenetic Dose Evaluation. I. Chromosome Aberration Levels in Remote Periods after Acute External Exposure in Different Situations].

Cytogenetic analysis of peripheral blood lymphocyte cultures of 22 persons was performed in remote terms after acute external γ-, γ-ß- or γ-neutron irradiation as a result of various accidents using the classical me- thod. The initial dose estimates were obtained using physical calculations, the method of measuring the EPR signal in tooth enamel, according to haematological and/or cytogenetic parameters. The purpose of this study was to obtain evidence about the state of the lymphocyte chromosome apparatus of people approxi- mately 17-50 years after an accidental radiation exposure. In general, elevated levels of chromosome aberra- tions were detected. An average correlation was observed between the atypical chromosome frequency and absorbed dose. It is proposed to use the obtained results in the future to explore the possibility of retrospective dose evaluation on the basis of a special computer program.

Technologies for retrospective radiation dosimetry.

Radiation dosimetry is an important task for assessing the biological damages created in human being due to ionising radiation exposure. Ionising radiation being invisible and beyond the perception of human natural sensors, the dosimetry equipments/systems are the utmost requirement for its measurement. Retrospective measurement of radiation doses is a challenging task as conventional radiation dosemeters are not available at the exposure site. The material/s in close proximity of exposed individual or individuals' biological samples may be used as retrospective radiation sensor for dosimetry purpose. Environment materials such as sand, bricks, ceramics, sand stones, quartz, feldspar, glasses and electronic chips have been utilised using TL (Thermoluminescence) techniques for retrospective gamma dose (min 10 cGy) measurement. Electron Spin Resonance techniques have been employed to human biological samples such as tooth enamel, bones, nails, hair, etc. and reported for dosimetry for ~20 cGy min dose measurement. Some commercial glasses have been found sensitive enough to measure the minimum gamma doses of the order of 100 cGy using TL techniques. For internal retrospective dosimetry, the radioactivity contamination assessment in food items, water, other edible product and ambient air are the prerequisites. The radioactivity concentration vis-à-vis their consumption rate may help in controlling the internal contamination and estimation of dose absorption in human body. Defence Laboratory, Jodhpur has been working extensively on the dosimetry techniques for external dose measurement using environmental material and developed portable contamination monitoring systems for food and water radioactivity measurement in the range of 50 Bq kg-1 to 1000 kBq kg-1 in 60 s measurement time. The recent research and development in the methodologies, equipments and systems undertaken towards capacity building and self-reliance in retrospective radiation dosimetry is reported in this paper.

Uranium Mine Proposed Experimental Design for Natural Background Gross Gamma Exposure Rates, Post Remediation Final Status Survey Sampling Density, and Radiological Water Quality Modeling for a Worst-case Catastrophic Failure, Coles Hill, Virginia.

ABSTRACT: Completely randomized experimental design statistical modeling techniques were employed to analyze exposure rate measurements for evaluating hypothetical natural background post uranium mill operations at Coles Hill, Virginia uranium milling processes. The proposed Coles Hill Uranium Mine is situated upstream of the Banister River. This River is nearly homogenous throughout the reach length used in analysis and feeds into the mouth of Kerr Reservoir, Lake Gaston, which serves as the main drinking water source for cities in the Hampton Roads area including Norfolk, Virginia Beach, and Chesapeake. A critical scan value (=DCGLscan) was developed to flag anomalies of surface contamination during simulated post remediation final status surveys. The natural background was critical for meeting the Multi-Agency Radiation Survey and Site Investigation Manual guidance for post remediation final status surveys. The overarching null hypothesis suggested that the selected mean natural background is equal to the survey unit's mean natural background. Using SAS Procedures Shapiro-Wilk Test, ANOVA, and CR, it was decided the exposure rate data was normal, had no extreme outliers, and no collinearity between the number of samples (=treatment) and the areas (=block). Using the q-hyper (hypergeometric) distribution, the soil sampling density was decided for a final status survey unit. The most likely worst-case catastrophic failure analysis, 500-year event, such as the1969 Hurricane Camille of 69 centimeters of rain in Nelson County, Virginia was included in the model. The model showed impact was minimal at most to the Banister River's drinking water and likely less than the Virginia's Drinking Water Standards for gross alpha, 226Ra and 228Ra, and total uranium.

Flow injection online spectrophotometric determination of uranium after preconcentration on XAD-4 resin impregnated with nalidixic acid.

In this work, spectrophotometer was used as a detector for the determination of uranium from water, biological, and ore samples with a flow injection system coupled with solid phase extraction. In order to promote the online preconcentration of uranium, a minicolumn packed with XAD-4 resin impregnated with nalidixic acid was utilized. The system operation was based on U(VI) ion retention at pH 6 in the minicolumn at flow rate of 15.2 mL min(-1). The uranium complex was removed from the resin by 0.1 mol dm(-3) HCl at flow rate of 3.2 mL min(-1) and was mixed with arsenazo III solution (0.05 % solution in 0.1 mol dm(-3) HCl, 3.2 mL min(-1)) and driven to flow through cell of spectrophotometer where its absorbance was measured at 651 nm. The influence of chemical (pH and HCl (as eluent and reagent medium) concentration) and flow (sample and eluent flow rate and preconcentration time) parameters that could affect the performance of the system as well as the possible interferents was investigated. At the optimum conditions for 60 s preconcentration time (15.2 mL of sample volume), the method presented a detection limit of 1.1 µg L(-1), a relative standard deviation (RSD) of 0.8 % at 100 µg L(-1), enrichment factor of 30, and a sample throughput of 42 h(-1), whereas for 300 s of the preconcentration time (76 mL of sample volume), a detection limit of 0.22 µg L(-1), a RSD of 1.32 % at 10 µg L(-1), enrichment factor of 150, and a sampling frequency of 11 h(-1) were reported.

Simultaneous determination of 210Pb and 90Sr and 210Po isolation in sludge samples using a plastic scintillation resin.

This study describes a new and fast method for separating 210Po from 210Pb and 90Sr, before simultaneously measuring the individual activities of the latter two radionuclides using a plastic scintillation resin (PSresin) in sludge samples taken from a drinking water treatment plant. This method speeds up the analysis process significantly by simultaneously measuring 210Pb and 90Sr in a single step. The method is reproducible and has a relative standard deviation of less than 25% for 210Pb, 210Po and 90Sr. The method was satisfactorily validated with an intercomparison sample and applied to sludge samples from a drinking water treatment plant. The minimum detectable activities for 0.9 g of sludge are 5.5 Bq/kg and 8 Bq/kg for 210Pb and 90Sr respectively when measured for 180 min, and 0.5 Bq/kg for 210Po when measured for 5000 min.

[Development of a simple quantitative method for the strontium-89 concentration of radioactive liquid waste using the plastic scintillation survey meter for beta rays].

Strontium-89 (89Sr: pure beta, E; 1.495 MeV-100%, halflife: 50.5 days) chloride is used as pain relief from bone metastases. An assay of 89Sr is difficult because of a pure beta emitter. For management of 89Sr, we tried to evaluate a simple quantitative method for the 59Sr concentration of radioactive liquid waste using scintillation survey meter for beta rays. The counting efficiency of the survey meter with this method was 35.95%. A simple 30 minutes measurement of 2 ml of the sample made the quantitative measurement of 89Sr practical. Reducing self-absorption of the beta ray in the solution by counting on the polyethlene paper improved the counting efficiency. Our method made it easy to manage the radioactive liquid waste under the legal restrictions.

Assessment of Occupational Exposure in Medical Practice in the Region of Hohhot, China, for the Period 2004-2020.

ABSTRACT: Individual monitoring is of great significance in efforts to protect the health of radiation workers and improve the level of radiation protection and management. This paper presents a retrospective analysis of occupational exposure to ionizing radiation from medical practice in the region of Hohhot, China, from 2004 to 2020. Results show that the average annual effective dose of occupationally exposed workers in medical practice significantly declined from 1.44 mSv in 2005 to 0.29 mSv in 2020 (Z = -5.23, P < 0.05). The number of medical radiation workers increased by 181%, the composition of radiation workers whose average annual effective dose exceeded 1 mSv decreased, and the number of radiation workers whose average annual effective dose was less than or equal to the minimum detection level (MDL) increased yearly over the 17-y study period. It was found that the dose of 1.106 mSv received by workers in interventional radiology is significantly higher than the doses of 0.52 mSv in dental radiology, 0.47 mSv in radiotherapy, and 0.33 mSv in all other medical uses (Z = 3.71, 9.13, 5.93, respectively; P < 0.05). The distribution ratios of workers in nuclear medicine and interventional radiology whose annual individual effective dose exceeded 5 mSv were 0.040 and 0.043, respectively, which are significantly higher than those in other occupational categories (χ2 = 307.11, P < 0.05). It was also shown that the average annual effective dose of 0.67 mSv in interventional radiology is significantly higher than that of 0.17 mSv in radiotherapy (Z = 3.39, P < 0.05) in 2020. According to these observations, the exposure of radiation workers in medical practice in Hohhot meets the requirements of the China standard. This study shows that the status of radiation workers in medical practice has obviously improved during the period 2004-2020. However, it is still necessary to focus on the protection of groups with high occupational exposure risk, and the continuous improvement of protection measures, monitoring means, and radiation workers' training, especially for the workers in the fields of interventional radiology and nuclear medicine.

Radiation health hazard and risks assessment among greenhouse farmers in Egypt, seasonal study.

OBJECTIVES: Greenhouses have been rapidly developing in Egypt in the recent years so as to overcome the problem of water shortage required for agriculture because agriculture in protected houses provides about 20-40% of the water consumption from agriculture in open lands. Greenhouses are widely used to cultivate different kinds of plants. Greenhouses are considered spacious, enclosed areas, in close contact with airtight and soil. They have been the main radon source for a long time. Radon and its progeny are released and trapped in the vacant space of greenhouses, causing health hazards for the farmers who work in them. Taking this into consideration, seasonal radon concentration levels have been monitored and measured in 8 greenhouses located at the city of Alexandria and Rosetta, Egypt. MATERIALS AND METHODS: Passive closed-and-open can techniques are mainly used to calculate these concentrations. Each can has an attached CR-39 polymeric nuclear track detector as a detector material. For a period of 1 year inside the chosen greenhouses, the dosimeter has been exposed to the local for four seasons, 3 months each. RESULTS: The average annual radon concentration in those greenhouses varies between the lowest radon concentration value of 310 ± 86 Bqm-3 in the glass greenhouse in Alexandria, and the highest concentration value of 543 ± 88 Bqm-3 in the plastic greenhouses in Rosetta, with a total average annual value of 476 ± 68 Bqm-3. A remarkable variation in the seasonal radon concentrations in the greenhouses is observed. Also, in the research at hand, the radon radiation dose received by a farmer working in the greenhouses is calculated according to the ICRP. The occupants' greenhouse exposure rate varies from 1.38 mJ h m-3 (0.39 WLM) in the plastic greenhouses to 2.42 mJ h m-3 (0.683 WLM) in the glass ones, with an average value of 1.68 mJ h m-3 (0.55 WLM) during that year. The workers' estimated effective dose per annum ranges between 1.94 mSv and 3.39 mSv with an average dose of 2.73 mSv. CONCLUSION: In all the examined greenhouses in the Egyptian cities of Alexandria and Rosetta, the estimated effective dose per year is in the lower limit range of the action level (3-10 mSv) recommended for greenhouse workers by the ICRP, and it does not exceed the ICRP's upper limit. If the farmers work for a long number of years in the greenhouses, the occupational exposure to radiation doses due to radon concentration must be taken into consideration.

Radiocesium concentrations in shallow water sediments (Matsukawa-ura Lagoon, Fukushima, Japan) from a compact NaI(Tl) scintillation spectrometer.

We collected continuous sedimentary 137Cs concentration data from a shallow fishery ground (Matsukawa-ura Lagoon, Fukushima, Japan) in 2016 using a new compact underwater NaI(Tl) scintillation spectrometer and a quantitative technique. 137Cs concentrations in sediments were low (approx. 40 Bq/kg DW) at the lagoon mouth and high (641.2 Bq/kg DW) at the head of the lagoon. Some areas of locally elevated 137Cs concentrations (>500 Bq/kg DW) were also found.

A new method of imaging particle tracks in solid state nuclear track detectors.

Solid state nuclear track detectors are used to determine the concentration of alpha particles in the environment. The standard method for assessing exposed detectors involves 2D image analysis. However 3D imaging has the potential to provide additional information relating to angle as well as to differentiate clustered hit sequences and possibly energy of alpha particles but this could be time consuming. Here we describe a new method for rapid high-resolution 3D imaging of solid state nuclear track detectors. A 'LEXT' OLS3100 confocal laser scanning microscope (Olympus Corporation, Tokyo, Japan) was used in confocal mode to successfully obtain 3D image data on four CR-39 plastic detectors. Three-dimensional visualization and image analysis enabled characterization of track features. This method may provide a means of rapid and detailed 3D analysis of solid state nuclear track detectors.

A scintillator-based range telescope for particle therapy.

The commissioning and operation of a particle therapy centre requires an extensive set of detectors for measuring various parameters of the treatment beam. Among the key devices are detectors for beam range quality assurance. In this work, a novel range telescope based on a plastic scintillator and read out by a large-scale CMOS sensor is presented. The detector is made of a stack of 49 plastic scintillator sheets with a thickness of 2-3 mm and an active area of 100 × 100 mm2, resulting in a total physical stack thickness of 124.2 mm. This compact design avoids optical artefacts that are common in other scintillation detectors. The range of a proton beam is reconstructed using a novel Bragg curve model that incorporates scintillator quenching effects. Measurements to characterise the performance of the detector were carried out at the Heidelberger Ionenstrahl-Therapiezentrum (HIT, Heidelberg, GER) and the Clatterbridge Cancer Centre (CCC, Bebington, UK). The maximum difference between the measured range and the reference range was found to be 0.41 mm at a proton beam range of 310 mm and was dominated by detector alignment uncertainties. With the new detector prototype, the water-equivalent thickness of PMMA degrader blocks has been reconstructed within ± 0.1 mm. An evaluation of the radiation hardness proves that the range reconstruction algorithm is robust following the deposition of 6,300 Gy peak dose into the detector. Furthermore, small variations in the beam spot size and transverse beam position are shown to have a negligible effect on the range reconstruction accuracy. The potential for range measurements of ion beams is also investigated.

Estimated internal exposure doses due to indoor radiocaesium contamination in residential houses after the Fukushima nuclear accident.

This work first reports the estimation of the internal exposure from ingestion of house dust and inhalation of aerosol, by employing a measured data on 137Cs activities, bioaccessibility (solubility to water and 1 M HCl), and particle size distribution. The house dust and aerosol samples were collected during the actual indoor cleaning by vacuuming and dusting, from 65 houses and buildings in proximity to the Fukushima Daiichi nuclear power plant (FDNPP) (1.6-16.1 km from the FDNPP) during a period from April 2016 to January 2019. Committed effective doses for an adult owing to the ingestion of house dust of 20 mg per day, which adheres to one's hands through the hand-to-mouth, and those owing to inhalation of aerosol during dusting for 1.5 h while wearing a mask, were calculated using DCAL software for each house or building, as 1.13 µSv and 4.55 µSv as maximum doses, respectively (as of March 2011). Both the committed effective doses, owing to ingestion and inhalation, were inversely correlated with the distance from the FDNPP, and positively correlated with the indoor surface contamination.

Bolete mushroom Boletus bainiugan from Yunnan as a reflection of the geographical distribution of 210Po, 210Pb and uranium (234U, 235U, 238U) radionuclides, their intake rates and effective exposure doses.

This pioneering study aimed to determine the activity concentrations of 210Po, 210Pb and uranium (234U, 235U, 238U) radionuclides in fruit bodies of wild bolete Boletus bainiugan Dentinger and to estimate its edible safety, which may give scientific evidence for the consumption of this species. The analyses were performed using alpha spectrometer after digestion, exchange resins separation and deposition. Measurement data were analysed and interpolation maps reflecting 210Po, 210Pb and uranium (234U, 235U, 238U) geographical distribution in Yunnan province (China) were presented. In addition, from the perspective of food safety, the possible related effective radiation dose to mushrooms consumers were estimated. The results indicated that 210Po, 210Pb and uranium (234U, 235U, 238U) radionuclides contents in B. bainiugan were significantly different with respect to geographical distribution, and their possible intake in a part of the region was considerably higher. A very interesting observation was done according to the values of 235U/238U activity ratio indicating the occurrence of uranium faction from the global fallout of nuclear weapon tests.

An exposure indicator for digital radiography: AAPM Task Group 116 (executive summary).

Digital radiographic imaging systems, such as those using photostimulable storage phosphor, amorphous selenium, amorphous silicon, CCD, and MOSFET technology, can produce adequate image quality over a much broader range of exposure levels than that of screen/film imaging systems. In screen/film imaging, the final image brightness and contrast are indicative of over- and underexposure. In digital imaging, brightness and contrast are often determined entirely by digital postprocessing of the acquired image data. Overexposure and underexposures are not readily recognizable. As a result, patient dose has a tendency to gradually increase over time after a department converts from screen/film-based imaging to digital radiographic imaging. The purpose of this report is to recommend a standard indicator which reflects the radiation exposure that is incident on a detector after every exposure event and that reflects the noise levels present in the image data. The intent is to facilitate the production of consistent, high quality digital radiographic images at acceptable patient doses. This should be based not on image optical density or brightness but on feedback regarding the detector exposure provided and actively monitored by the imaging system. A standard beam calibration condition is recommended that is based on RQA5 but uses filtration materials that are commonly available and simple to use. Recommendations on clinical implementation of the indices to control image quality and patient dose are derived from historical tolerance limits and presented as guidelines.

High-energy radiation monitoring based on radio-fluorogenic co-polymerization. I: Small volume in situ probe.

A method of radiation dosimetry is described which is based on the radiation-induced initiation of polymerization of a bulk monomer (e.g. methyl methacrylate) containing a small concentration (about 100 ppm) of a compound which is non-fluorescent but which becomes highly fluorescent when it is incorporated into a growing polymer chain of the bulk monomer. We call the overall process 'radio-fluorogenic co-polymerization' or RFCP for short. The method is illustrated by results on the in situ monitoring of the accumulated dose within the irradiation chamber of a cobalt-60 gamma-ray source using a small plastic capsule containing about 0.2 ml of an RFCP solution. Remote monitoring of the fluorescence is carried out on a timescale of seconds using optical fibres connecting the probe to a 360 nm LED excitation source and a miniature spectrophotometer. The fluorescence is permanent and the intensity is linearly proportional to the accumulated dose from a few tenths of a gray up to hundreds of gray. The sensitivity to dose depends on the polymerizable monomer used and obeys a square root dependence on dose rate over the range studied, 0.27-3.76 Gy min(-1). The polymeric nature of the fluorescent product suggests that the RFCP effect could be used to provide fixed two- or three-dimensional fluorescent images of dose deposition in gel films or phantoms.

Compliance of Bhabhatron-II telecobalt unit with IEC standard - Radiation safety.

Bhabha Atomic Research Centre, Mumbai, India designed and developed a telecobalt unit, which was named as Bhabhatron-II. In this paper, the results pertaining to radiation safety of indigenously developed Bhabhatron-II telecobalt unit are reported. The various tests were carried out as per requirements of International Electrotechnical Commission standard and acceptance criteria developed nationally. Various devices such as CaSO4:Dy based thermoluminescent dosimeters, farmer type ionization chamber, water phantom and radiographic films were used. All the parameters pertaining to radiation leakage/transmission were within the tolerance limits as per IEC-60601-2-11 standard except the collimator transmission through X collimators (upper jaw), which marginally exceeds the tolerance limit.