Assessment of Radiation dose from Inhalation of Outdoor Dust Containing Natural Radionuclides

The 238U, 232Th and 40K concentrations were estimated in the size-fractionated urban surface deposited sediments in Ekaterinburg, Russia. The average concentrations of 238U, 232Th and 40K in dust fraction (0.002–0.05 mm) are 48 ± 7, 28 ± 1 and 510 ± 20 Bq/kg, respectively. The effective dose is estimated depending on the suggested daily scenarios of different exercises which can be assigned to light, moderate and vigorous activity. The results show that the total effective dose received during 20 years by an adult with the light activity is 5.6 μSv under exposure to air dust concentration 1 × 10−4 g/m3, which is typical for the city of Ekaterinburg. Although for the moderate and vigorous activities the total effective dose is 9.9 μSv and 48.8 μSv, respectively, during 20 years at air dust concentration equal to the diurnal Maximum Permissible Limit (1.5 × 10−4 g/m3). Thus, the effective doses due to natural radionuclides in the dust fraction are relatively low in comparison ICRP reference level.

Radiation Dose Evaluation of Typical Design Basis Accident for Advanced PWR in China

The loss of coolant accident (LOCA) is one of the typical design basis accidents for nuclear power plant. Radionuclides leak to the environment and cause harm to the public in LOCA. Accurate evaluation of radioactivity and radiation dose in accident is crucial. The radioactivity and radiation dose model in LOCA were established, and used to analyze the radiological consequence at exclusion area boundary (EAB) and the outer boundary of low population zone (LPZ) for Hualong 1. The results indicated that the long half-life nuclides, such as 131I, 133I, 135I, 85Kr, 131mXe, 133mXe and 133Xe, released to environment continuously, while the short half-life nuclides, such as 132I, 134I, 83mKr, 85mKr, 87Kr, 88Kr, 135mXe and 138Xe, no longer released to environment after a few hours in LOCA. 133Xe may release the largest radioactivity to environment, more than 1015Bq. Inhalation dose was the major contribution to the total effective dose. The total effective dose and thyroid dose of Hualong 1 at EAB and the outer boundary of LPZ fully met the requirements of Chinese GB6249.

Influence of Different Arm Positions in the Localizer Radiograph(s) on Patient Dose during Exposure-Controlled CT Examinations of the Neck to Pelvis

Our aim was to examine the impact of different arm positions during imaging of the localizer radiograph(s) on effective dose for exposure-controlled computed tomography (CT) (Siemens/Canon) scans of the neck to pelvis. An anthropomorphic whole-body phantom was scanned from the neck to pelvis with the arms positioned in three different ways during the acquisition of the localizer radiograph: (i) above the head, (ii) alongside the trunk, and (iii) along the trunk with the hands placed on the abdomen. In accordance with clinical routines, the arms were not included in the subsequent helical scans. Effective doses were computed to a standard-sized patient (male/female) using a dedicated system-specific Monte Carlo-based software. Effective doses for the Canon CT scanner for the different alternatives (male/female) were (a) 5.3/6.62 mSv, (b) 5.62/7.15 mSv and (c) 5.92/7.44 mSv. For the Siemens CT scanner, effective doses were (a) 4.47/5.59 mSv, (b) 5.4/6.69 mSv and (c) 5.7/6.99 mSv. Arms placed above the head during localizer radiograph imaging in the current CT procedures substantially reduced the total effective dose to the patient.

Dose assessment for NPP staff for beyond design basis accident taking into account typical site infrastructure

Assessment of radiation effect on nuclear power plant staff was made for beyond design basis accident (4 hours period). The considered accident scenario includes emergency radionuclide emission through containment bypass. Assessment of radiation effect on NPP staff was done on the basis of radionuclide concentration distribution on site considering typical infrastructure. Concentration mapping was calculated by developed program module for COMSOL 3.5a application. The obtained data included average volume radionuclide activities in lower air layer, total inhalation dose, effective dose of external exposure, equivalent and effective dose in thyroid and total effective dose for NPP staff during beyond design basis accident. Doses from radioactive cloud (external exposure) and from inhalation (internal exposure) were estimated for the following radionuclides: 137Cs, 134Cs, 131I, 133I, 90Sr. In the case of selected beyond design basis accident the total effective dose of staff is 61,98 mSv for the first 4 hours after the accident beginning. This number is slightly above the threshold of the allowable annual dose limit for personnel in emergency situations (50 mSv). Taking into account that short-lived iodine radionuclides 131I и133I give the main contribution in the dose (50.23 mSv including 27.23 mSv for thyroid), such emergency actions as respiratory protection and iodine prophylaxis for the staff can significantly decrease the received doses.

Organ dose and total effective dose of whole-body CT in multiple myeloma patients

Objective To evaluate organ dose and total effective dose of whole-body low-dose CT (WBLDCT) performed on different CT-scanner models in patients with multiple myeloma (MM) and to compare it to the effective dose of radiographic skeletal survey and representative diagnostic CTs. Material and methods We retrospectively analyzed data from 228 patients (47.4% females, mean age 67.9 ± 10.4 years, mean weight 81.8 ± 22.4 kg) who underwent WBLDCT for the work-up or surveillance of MM. Patients were scanned using one of six multi-detector CT-scanners. Organ doses and total effective doses per scan were calculated using a commercially available dose-management platform (Radimetrics, Bayer Healthcare, Leverkusen, Germany). The median effective dose was compared to radiographic skeletal survey and representative diagnostic CTs. Results The mean effective dose of our WBLDCT-protocol was 4.82 mSv. A significantly higher effective dose was observed in females compared to males (4.95 vs. 4.70 mSv, P = 0.002). Mean organ dose ranged from 3.72 mSv (esophagus) to 13.09 mSv (skeleton). Mean effective dose varied amongst different CT-scanners (range 4.34–8.37 mSv). The median effective dose of WBLDCT was more than twice the dose of a skeletal survey (4.82 vs. 2.04 mSv), 23% higher than a diagnostic contrast-enhanced chest CT (3.9 mSv), 46% lower than a diagnostic contrast-enhanced abdomen/pelvis CT (9.0 mSv), and 45% lower than a lumbar spine CT (8.7 mSv). Conclusions WBLDCT in MM has a higher effective dose than a radiographic skeletal survey, but a lower effective dose than diagnostic CTs of lumbar spine, abdomen and pelvis. This underlines the broad applicability of WBLDCT in the management of MM patients.

Medical Treatment and Dose Estimation of a Person Exposed to Tritium

In this study, we aimed to investigate the damaging effects and clinical therapy of internal contamination with tritium to provide information and gain experience for medical treatments in case of an emergency due to a nuclear accident. Histories were taken by several doctors who observed and recorded the clinical symptoms of the patient described herein. The general health situation was evaluated by laboratory and equipment analyses. Tritium concentrations in the urine were estimated according to relevant standards during the monitoring period using a liquid scintillation counting method. Clinical observation revealed that the patient had symptoms of mild asthenia and sleep disorder with improvement after appropriate treatment. The last committed effective dose was determined through measurement of the urine tritium concentration and dose estimation and was estimated to be 0.123 mSv; the total effective dose was 14.536 mSv. The medical treatment and dose estimation in this patient with tritium contamination were successful and can provide a reference for similar cases in the future.

DETERMINATION OF THE TOTAL EFFECTIVE DOSE OF EXTERNAL AND INTERNAL EXPOSURE BY DIFFERENT IONIZING RADIATION SOURCES

The purpose of the research is to develop an integrated technique for determining the effective dose (E) of external and internal exposure by different sources of ionizing radiation. The proposing technique for determining the total effective dose is based on three methods of calculation. The first one is multiplying the value of the individual dose equivalent $H_{p}(10)$ by the factor of 0.642 to account for radiation shielding by various organs and tissues and its backscattering. The second method is multiplying $H_{p}(10)$ by the conversion factor of air kerma in free air in a plate phantom, depending on the photon energy. The third method is multiplying $H_{p}(10)$ by the sum of the radiosensitivity coefficients of various organs and tissues. As a result of research, a complex method was developed for determining the total effective dose, composed of doses of cosmic radiation, external gamma-, beta- and neutron radiation, internal exposure from radionuclides, including CDP of radon and thoron, entering the body through the organs of digestion and respiration. The proposed technique for determining the total effective dose allows one to take into account the comprehensive effect of ionizing radiation sources on a person and to obtain a more accurate measure of radiation risk than the existing methods provide.

Radiation Examination of Newborns with General Therapeutic Hypothermia

Purpose: Search of possible criteria of the diagnosis of occupational lung cancer in workers of uranium mines on the basis of the analysis of literary data. Material and methods: The analysis of literary data with the purpose of allocation of possible criteria and their use for the diagnosis of occupational lung cancer at 6 employees of uranium mines. Results: The following criteria for the diagnosis of occupationally caused lung cancer at workers of uranium mines are marked out: • Total effective dose of radiation exposure is more 200–250 mSv (40–50 WLM). • Period in underground conditions is not less than 10 years. • Dust content in a workplace is more than 1 mg/m3. • Hygienic assessment of working conditions – the 3rd class, 3.2–3.4 degree. • The latent period of development of a tumor is not less 10 years. • Development of primary and multiple synchronous or metachronous lung cancer. Also the diagnosis of occupational lung cancer the pulmonary anamnesis (frequent bronchitis, pneumonia, chronic bronchitis of the smoker) has to be considered. On the basis of the marked-out criteria documents of 6 employees of uranium mines, at which lung cancer has been revealed, are considered. On the basis of the carried-out analysis at 5 patients relation of a disease with professional activity has been established. One patient was denied this relation. Conclusion: Authors offer this expert approach to experts’ discussion as above-mentioned criteria is planned to be used by the pathologists who are carrying out observation of workers of uranium production and for the solution of questions of relation of a disease with professional activity of the patient.

Possible Criteria of the Diagnosis of Occupational Lung Cancer in Workers of Uranium Mines

Purpose: Search of possible criteria of the diagnosis of occupational lung cancer in workers of uranium mines on the basis of the analysis of literary data. Material and methods: The analysis of literary data with the purpose of allocation of possible criteria and their use for the diagnosis of occupational lung cancer at 6 employees of uranium mines. Results: The following criteria for the diagnosis of occupationally caused lung cancer at workers of uranium mines are marked out: • Total effective dose of radiation exposure is more 200–250 mSv (40–50 WLM). • Period in underground conditions is not less than 10 years. • Dust content in a workplace is more than 1 mg/m3. • Hygienic assessment of working conditions – the 3rd class, 3.2–3.4 degree. • The latent period of development of a tumor is not less 10 years. • Development of primary and multiple synchronous or metachronous lung cancer. Also the diagnosis of occupational lung cancer the pulmonary anamnesis (frequent bronchitis, pneumonia, chronic bronchitis of the smoker) has to be considered. On the basis of the marked-out criteria documents of 6 employees of uranium mines, at which lung cancer has been revealed, are considered. On the basis of the carried-out analysis at 5 patients relation of a disease with professional activity has been established. One patient was denied this relation. Conclusion: Authors offer this expert approach to experts’ discussion as above-mentioned criteria is planned to be used by the pathologists who are carrying out observation of workers of uranium production and for the solution of questions of relation of a disease with professional activity of the patient.