Personal Dose Research Articles

Beam port filters in a TRIGA MARK III nuclear reactor to produce epithermal neutrons for BNCT

Glioblastoma multiforme is the most common and aggressive brain tumor and it is difficult to treat with conventional surgery, chemotherapy, or radiation therapy. An alternative treatment is boron neutron capture therapy which requires an energy modulated beam of neutrons and a10B drug capable of adhering to the tumor. In this work, MCNP6 Monte Carlo code was used to evaluate the effect on the neutron spectrum by placing two filters along the radial beam tube of the TRIGA Mark III nuclear reactor of ININ in Mexico. Every filter was made with the same amount and type of materials: Steel and Graphite for filter 1 and Cadmium, Aluminum, and Cadmium (Cd + Al + Cd) for filter 2. Two cases were analyzed for each filter as follows: Case A for filter 1 was considering 30 cm of steel and 30 cm of graphite, while for case B, the dimensions of filter 1 were 15 cm of steel, 15 cm of graphite, 15 cm of steel and 15 cm of graphite. Cases A and B for filter 2 were analyzed considering the same dimensions and amount of materials. The work was in the aim to produce epithermal neutrons for boron neutron capture therapy. Neutron spectra were calculated at three sites along the beam tube and two sites outside the beam tube; here, the ambient dose equivalent, the personal dose equivalent, and the effective doses were also estimated. At a distance of 517 cm of core, in case B, results in an epithermal-to-thermal neutron fluence ratio of 30.39 was obtained being larger than the one recommended by the IAEA of 20.

Occupational radiation dose of personnel involved in sentinel node biopsy procedure.

Sentinel node biopsy is a procedure used for axillary nodal staging in breast cancer surgery. The process uses radioactive 99mTc isotope for mapping the sentinel node(s) and all the staff involved in the procedure is potentially exposed to ionizing radiation. The colloid for radiolabelling (antimone-sulphide) with 99mTc isotope (half-life 6h) is injected into the patient breast. The injection has activity of 18.5MBq. The surgeon removes the primary tumor and detects active lymph nodes with gamma detection unit. The tumor as well as the active nodal tissue is transferred to pathologist for the definitive findings. The aim of the study was to measure dose equivalents to extremities and whole body for all staff and suggest practice improvement in order to minimize exposure risk. The measurements of the following operational quantities were performed: Hp(10) personal dose equivalent to whole body and Hp(0.07) to extremities for staff as well as ambiental dose for operating theatre and during injection. Hp(0.07) were measured at surgeon's finger by ring thermoluminescent dosimeter (TLD) type MTS-N, and reader RADOS RE2000. Surgeon and nurse were wearing TLD personal dosimeter at the chest level. Anesthesiologist and anesthetist were wearing electronic personal dosimeters, while pathologist was wearing ring TLD while manipulating tissue samples. Electronic dosimeters used were manufactured by Polimaster, type PM1610. All TLD and electronic dosimeters data were reported, including background radiation. Background radiation was also monitored separately. Personal TLDs are standard for this type of personal monitoring, provided by accredited laboratory. Measurements of ambiental dose in workplaces of other staff involved around the patient was performed before the surgery took place, by calibrated survey meters manufactured by Atomtex, type 1667. The study involved two surgeons and one pathologist, two anesthesiologists and three anesthetists during two months period. The doses received by all staff are evaluated using passive and active personal dosimeters and ambiental dose monitors and practice was improved based on results collected. Average annual whole body dose for all staff involved in the procedure was less than 0.8mSv. Extremity dose equivalents to surgeon and pathologist were far below the limits set for professionally exposed (surgeon) and for public (pathologist). Although has proven to be very safe for all staff, additional measures for radiation protection, in accordance to ALARA principle (As Low As Reasonably Achievable) should be conducted. The recommendations for practice improvement with respect to radiation protection were issued.

ASSESSMENT OF OCCUPATIONAL RADIATION DOSES IN DIFFERENT DIAGNOSTIC, INTERVENTIONAL AND THERAPEUTIC RADIOLOGY AND MOLECULAR IMAGING SERVICES IN OMAN.

This study aimed at assessing occupational radiation doses in different diagnostic, interventional and therapeutic services. Personal dose equivalent, Hp(10), of 116 medical radiation workers, all with 3 y of dose records (2015-18), were collected from the TLD dosimetry service at the Sultan Qaboos University Hospital-a 700-bed tertiary care teaching hospital in Oman. The doses were measured using calibrated thermo-luminescence dosemeters (TLD-100 (LiF:Mg,Ti)). Five occupational groups, diagnostic radiology, interventional radiology, nuclear medicine, medical physicists and nurses, were considered. Average, maximum and median cumulative doses were estimated and compared against the annual dose limit (20mSv per y) and the local dose investigation level (DIL) (6mSv per y). Personal doses (average:maximum:median) for diagnostic radiology, interventional radiology, nuclear medicine, medical physicists and nurses group were found to be 0.05:0.90:0.00, 0.05:0.50:0.00, 1.20:7.40:0.40, 0.16:1.40:0.00 and 0.10:2.10:0.00mSv, respectively. The findings of this study suggest, at the exception of nuclear medicine, lower DILs for all occupational groups.

Analysis on the status of occupational health of medical radiation workers in China in 2019

Objective: To grasp the occupational health monitoring of radiation workers in medical institutions across the country, and to discover weak links in the prevention and treatment of occupational radiation diseases. Methods: In 2020 January, according to the monitoring data of the "National Radiation Health Information Platform" (Occupational Radiation Disease and Occupational Health Monitoring Subsystem and Occupational Radiation Disease Reporting Subsystem) , the national occupational health monitoring data from January 1 to December 31, 2019, including the number of radiation workers in medical institutions, occupational health examinations, personal dose monitoring and occupational radiation disease diagnosis, were descriptive analyzed. Results: There were a total of 394436 radiation workers in medical institutions across the country. The number of radiation workers in various provinces was quite different, with a median of 10206, which was positively correlated with the number of permanent residents in each province (r=0.947) . There were 376 personal dose monitoring institutions nationwide, and the personal dose monitoring rate of radiation workers in medical institutions was 96.61% (381045/394436) . There were 419 occupational health inspection institutions for radiation workers across the country, and 269 (64.20%) used software to print physical examination forms. A total of 334455 radiation workers in medical institutions had been subjected to occupational health examinations. The rate of occupational health examinations for radiation workers in medical institutions was 84.79% (334455/394436) . The abnormal rate of chromosomal aberrations in peripheral blood lymphocytes of radiation workers in medical institutions was 0.33% (776/233571) , the detection rate of posterior posterior subcapsular turbidity was 0.63% (2093/334455) , and the abnormality rate of thyroid color ultrasound was 28.49% (14946/52464) . In 2019, a total of 16 cases of occupational radiation diseases were reported. Conclusion: The personal dose monitoring rate and occupational health examination rate of medical radiation workers nationwide are relatively high, but the quality of lymphocyte chromosome aberration analysis, eye lens examination and thyroid color photograph examination needs to be further improved.

Survey of self-reported radiation safety practices among North American veterinary technicians involved in equine radiography using portable x-ray equipment

To describe self-reported radiation safety practices by equine veterinary technicians in North America and identify factors associated with these practices. 154 equine technicians. An electronic questionnaire regarding radiation safety practices during the use of portable x-ray equipment was sent to 884 members of the American Association of Equine Veterinary Technicians and Assistants. Data were summarized, and various factors were evaluated for associations with reported safety practices. 221 of 884 (25.0%) questionnaires were completed, including 154 by equine technicians who had been involved in equine radiography as x-ray tube operators, cassette holders, or both in the previous year. Lead apron use was suboptimal, reported as "always" for 80.0% (104/130) of tube operators and 83.1% (123/148) of cassette holders. Approximately 20% of participants never wore thyroid shields, and approximately 90% never wore lead eyeglasses. Almost 50% of participants did not have lead eyeglasses available. Although > 55% of participants always held the x-ray equipment by hand, 58.4% (73/125) of tube operators and 25.0% (35/140) of cassette holders never wore gloves. Cassette holders wore lead gloves and personal radiation dose-monitoring devices significantly more frequently than did tube operators. Compliance of North American equine technicians with radiation safety recommendations by the National Council on Radiation Protection and Measurements was suboptimal. Improvements in radiation safety training and education, strengthening the connection between academic institutions and private practices, and greater availability and requirement of personal protective equipment use by senior clinicians and employers might aid in improving safety practices.

ASSESSMENT OF EXTERNAL OCCUPATIONAL DOSE OF PHOSPHATE MINE WORKERS IN SAUDI ARABIA USING THERMOLUMINESCENT DOSEMETERS.

Workers in the mining industry face the problem of radiation exposure from naturally occurring radioactive materials. Thus, this study aimed to estimate a Hp (10) doses for mine workers in the phosphate mining industry in Saudi Arabia. The personal dose equivalent [Hp (10)] of 606 mine workers in the phosphate mining industry in Saudi Arabia were obtained from 2016 to 2019 using thermoluminescent dosemeters (TLDs). The results showed that the annual mean Hp (10) of all mine workers averaged over the study period was 0.66mSv (SD=0.45), which is within the range of occupational doses reported worldwide. Most of the Hp (10) were <0.49mSv, and the maximum Hp (10) was 3.55mSv. Nonetheless, internal exposure should be evaluated along with external exposure to estimate a comprehensive baseline occupational dose for mine workers in the phosphate mining industry in Saudi Arabia.

HCl-doped poly (para-nitro aniline-co-para-toluidine) thin film as a gamma ray dosimeter

A semiconductor copolymer, HCl doped poly (para-nitro aniline-co-para-toluidine) [DPPNPT] was prepared by oxidative polymerization route in an acidic medium. The structural properties of the copolymer were characterized by several techniques. Physical vapor deposition technique was used for fabrication of the copolymer thin film [DPPNPT]TF of 100 nm thickness. Material studio 7.0 was calculated with the density functional theory (DFT), geometrical trials including the highest molecular orbits (HOMOs), the lowest unoccupied molecular orbitals (LIMOs), and the other active parameters were obtained. The optical parameters have demonstrated that the thin film has a high absorption range of 2 to 6 eV. Dosimetric properties are considered as another utilization of DPPNPT thin film. Thermoluminescence (TL) properties such as glow curves, different gamma doses response, and dose fading nature were tested. Thermoluminescence examinations of DPPNPT gamma-irradiated showed a single strong TL glow peak located at 350°C. Three unresoluted glow peaks of the [DPPNPT]TF films after gamma irradiation have been obtained. A linear correlation was obtained in the response curve start with 0.01Gy and extended to 2Gy. The total integral value of the TL signal showed a fixation through one month of storage of the DPPNPT compound. TL kinetics in deep traps were used to calculate resolute peaks activation energies. Based on obtained results the [DPPNPT]TF films are a good candidate for detection and monitoring personal gamma-ray doses.

Determination of Calibration X-Ray Beam Qualities and Establish a Set of Conversion Coefficients for Calibration of Radiation Protection Devices Used in Diagnostic Radiology

The use of X-ray facilities in calibrating radiation measuring equipment in diagnostic radiology requires an exact knowledge of the radiation field. X-ray spectrums are made narrow beam by proper filtration recommended by several international organizations. In the present study, the experimental determination of X-ray calibration qualities and analysis of conversion coefficients from air Kerma to ambient and personal dose equivalent is carried for X-ray beam irradiator X80-225kV as per ISO narrow spectrum series at Secondary Standard Dosimetry Laboratory (SSDL) in Bangladesh. The X-ray beam involved in half value layer, effective energy, beam homogeneity coefficient and consistency of X-ray production from the generator (kV and mA) is conducted. A discrepancy of half value layer has been observed for N200 beam code by -8.5% which leads to the deviation of effective energy by -7.7% with a standard deviation of 1.3%. The conversion coefficients from the air kerma to dose equivalent that satisfying the condition of ICRU sphere is established to obtain radiation qualities and compared with values referred by other standard laboratories. A deviation of 0.87% has been observed for H*(10) and H¢(0.07) in between ISO and BCRU empirical relation which is insignificant. A set of conversion coefficients for Hp(10) and Hp(0.07) has also been calculated for ICRU four element tissue.

SIMULATION OF NEUTRON RESPONSE FUNCTIONS OF SILICON SENSOR APPLIED TO REAL-TIME PERSONAL ALBEDO NEUTRON DOSEMETER IN THE ENERGY RANGE BETWEEN 0.01EV AND 10KEV.

Neutron response functions of a silicon sensor, which is applied to a new real-time personal albedo neutron dosemeter, have been simulated for low energy neutrons from 0.01eV to 10keV using the Monte Carlo technique. The angular neutron response functions were obtained by multiplying simulated neutron energy spectra crossing the neutron sensor and the cross-section of the 6Li(n,t)4He reaction. The neutron response functions have been closed to the dose conversion coefficient of personal doses, Hp(10) recommended by the International Commission on Radiological Protection by selecting neutrons incident from angles of 105° to 180° with respect to an axis perpendicular to an acrylic phantom surface. From these simulation results, the neutron energy response function has been improved by shielding the sensor with cadmium box without a face toward the phantom. The neutron sensor provides a good conformance to the Hp(10) conversion coefficients within 15% for low energy neutrons.

Organ Dose Reconstruction Applicable for a Japanese Nuclear Worker Cohort: J-EPISODE.

An evaluation of cancer risk based on organ-absorbed dose is underway for the Japanese Epidemiological Study on Low-Dose Radiation Effects (J-EPISODE), which has analyzed health effects in association with radiation exposure evaluated with the personal dose equivalent Hp(10). Although the concept of effective dose and its operational definition of Hp(10) are widely used for radiological protection purposes, effective dose is not recommended for epidemiological evaluation. Organ-absorbed dose was instead adopted for the IARC 15-Country Collaborative study (15-Country study), the International Nuclear Workers Study (INWORKS), the Mayak worker study, and the Life Span Study (LSS) of atomic bomb survivors. The reconstruction method in J-EPISODE followed in principle the approach adopted in the 15-Country Study. As part of the approach of J-EPISODE, a conversion factor from photon dosimeter reading to air kerma was developed using dosimeter response data, which were measured by the experiment using an anthropomorphic phantom, and it was confirmed that the 15-Country study’s assumption of photon energy and geometry distribution in a work environment applied to Japanese nuclear workers. This article focuses on a method for reconstructing the conversion factor from photon dosimeter reading to organ-absorbed photon dose for a Japanese nuclear worker cohort. The model for estimating the conversion factor was defined under the assumption of a lognormal distribution from three concerned bias factors: (1) a dosimeter reading per air kerma, i.e., dosimeter response; (2) an organ-absorbed dose per air kerma; and (3) a factor relating to the differences in dose concepts and calibration practices between the roentgen dosimeter era and the present. Dosimeter response data were cited from the companion paper. Data on organ-absorbed photon dose per air kerma were estimated using a voxel phantom with the average Japanese adult male height and weight. The bias factor for the recorded dose in the roentgen era was defined, considering the backscatter radiation from the human body. The estimated values of organ-absorbed photon dose per air kerma were almost the same as those in ICRP Publication 116, revealing that the effect of differences in body size was almost negligible. The conversion factors from dosimeter reading to organ-absorbed dose were estimated by period (the roentgen era or from then), nuclear facility type (nuclear power plant or other), dosimeter type, and tissue or organ. The estimated conversion factors ranged from 0.7 to 0.9 (Gy Sv−1). The estimated cumulative organ-absorbed photon dose for the participants of J-EPISODE demonstrated that organ-absorbed dose values were approximately 0.8 times the recorded doses if neglecting dose-unit differences. J-EPISODE reconstructed an organ-absorbed dose conversion factor and will evaluate the risk of cancer mortality and morbidity using the organ-absorbed dose in the future.

Evaluating uncertainty of some radiation measurand using Monte Carlo method

Evaluating measurement uncertainty of a physical quantity is a mandatory requirement for laboratories within the recognition ISO/IEC 17025 certification to access reliability of measured results. In this work, the uncertainty of ionizing radiation measurements such as air-kerma, personal dose equivalent Hp(d) was evaluated based on GUM method and Monte Carlo method. An uncertainty propagation software has been developed for evaluation of the measurement uncertainty more convenient.

Eye lens dosimetry in Canadian CANDU nuclear power plants based on operational dosimetric quantities H[formula omitted](10) and H[formula omitted](0.07)

In this article, we present a methodology for performing eye lens dosimetry in CANDU nuclear power plants using an existing and highly accurate Harshaw 4-element TLD-700 dosemeter. This dosemeter, which has been specially designed for Ontario Power Generation (OPG) and Bruce Power (BP), measures the deep and shallow personal dose equivalent quantities Hp(10) and Hp(0.07), respectively. Using these measured personal dose equivalent quantities and applying a beta-ray strength scaling factor to the Hp(0.07) measurement in particular, we have developed an algorithm that can be used to calculate the dose to the lens of the eye in mixed beta–gamma fields. This scaling factor has been developed and is primarily based on results obtained from extensive collaborative study, performed by Ontario Power Generation (OPG), Bruce Power (BP) and McMaster University, through Candu Owners Group (COG) support (Bohra et al., 2021; Laranjeiro et al., 2020). Furthermore, scaling factor F, also includes effects of protective glass eyewear and results from Whole body dosimetry intercomparison exercises. The algorithm to calculate eye lens dose at CANDU power plants has been developed, based on this scaling factor and operational dosimetric quantities Hp(10) and Hp(0.07)

Managing occupational doses with smartphones in interventional radiology.

PurposeThis study presents a prototype smartphone application for occupational dosimetry in interventional practices based on electronic personal dosimeters to assist in dose monitoring.MethodsThe prototype receives and records information from the occupational dose report containing the cumulative dose of electronic personal dosimeters worn over the apron at chest level and electronic area dosimeters located on C‐arms (reference dosimeters), for each fluoroscopy‐guided procedure. Using their smartphones, personnel involved in interventional practices can review and compare their occupational records with an investigation level, the dose limits, and their department colleagues (anonymously). The ratio between H p(10) measured by the personal and the reference dosimeters at the C‐arm is presented as an indicator of consistent use of suspended operator shield. Some general results extracted from the first months of use are presented.ResultsThe reference dosimeter located at the C‐arm (without lead protection and acting as an ambient dosimeter) recorded in one of the laboratories 217 mSv during 308 procedures over 5 months, showing an indication of the radiation risk present in an interventional laboratory. The ratio between the personal cumulative dose and the dose at a reference C‐arm dosimeter ranged from 0.2% to 1.67% (a factor of 8.5) for different interventionalists. These differences suggest different protection habits among interventional operators, as well as a target for dose reduction.ConclusionsWith this system, professionals have easy access to their occupational dosimetry records (including information on the workload) in the setting of their interventional departments, to thereby actively engage in the protection process.

Study of whole-body occupational radiation exposure in the industrial radiography in Bangladesh

ObjectiveIn order to understand the complete scenario of the effectiveness of radiation protection practice in the workplace, especially in the industrial radiography and also to analyze the trends with other related studies, epidemiological studies and legal purposes, the assessment and register of the effective dose plays a significant role. Therefore, efforts have been given in the assessment of collective effective dose, mean effective dose, prediction of lifetime cancer risk, and contribution of different age group workers in the collective effective dose. MethodsThe occupational radiation exposures for 472 workers were investigated in industrial radiography throughout Bangladesh from 2015 to 2018 by using thermoluminescent dosimeter (TLD). By using a Harshaw TLD reader (Model-4500), the effective dose was measured in a quarterly basis throughout the year. Based on the value of personal dose equivalent Hp(10), database was prepared and recorded. ResultsThe collective effective dose was 36.1, 40.7, 28.8 and 37.5 man·mSv among 105, 102, 100 and 165 radiation workers in 2015, 2016, 2017 and 2018, respectively. The maximum effective dose received by radiation workers was 6.0, 7.1, 6.9 and 19.9 ​mSv in 2015, 2016, 2017 and 2018, respectively, which remained within the stipulated dose limits imposed by Nuclear Safety and Radiation Control (NSRC) Rules-1997, Bangladesh and International Commission on Radiological Protection (ICRP-103). ConclusionThis kind of monitoring would help to construct a national database that will be used by the end users to improve their implementation of optimization in occupational radiation protection in industrial radiography.

Mortality among medical radiation workers in the United States, 1965–2016

Background Estimates of radiation risks following prolonged exposures at low doses and low-dose rates are uncertain. Medical radiation workers are a major component of the Million Person Study (MPS) of low-dose health effects. Annual personal dose equivalents, H P(10), for individual workers are available to facilitate dose-response analyses for lung cancer, leukemia, ischemic heart disease (IHD) and other causes of death. Materials and methods The Landauer, Inc. dosimetry database identified 109,019 medical and associated radiation workers first monitored 1965–1994. Vital status and cause of death were determined through 2016. Mean absorbed doses to red bone marrow (RBM), lung, heart, and other organs were estimated by adjusting the recorded H P(10) for each worker by scaling factors, accounting for exposure geometry, the energy of the incident photon radiation, sex of the worker and whether an apron was worn. There were 4 exposure scenarios: general radiology characterized by low-energy x-ray exposure with no lead apron use, interventional radiologists/cardiologists who wore aprons, nuclear medicine personnel and radiation oncologists exposed to high-energy photon radiation, and other workers. Standardized mortality ratio (SMR) analyses were performed. Cox proportional hazards models were used to estimate organ-specific radiation risks. Results Overall, 11,433 deaths occurred (SMR 0.60; 95%CI 0.59,0.61), 126 from leukemia other than chronic lymphocytic leukemia (CLL), 850 from lung cancer, and 1654 from IHD. The mean duration of monitoring was 23.7 y. The excess relative rate (ERR) per 100 mGy was estimated as 0.10 (95% CI −0.34, 0.54) for leukemia other than CLL, 0.15 (0.02, 0.27) for lung cancer, and −0.10 (–0.27, 0.06) for IHD. The ERR for lung cancer was 0.16 (0.01, 0.32) among the 55,218 male workers and 0.09 (–0.19, 0.36) among the 53,801 female workers; a difference that was not statistically significant (p-value = 0.23). Conclusions Medical radiation workers were at increased risk for lung cancer that was higher among men than women, although this difference was not statistically significant. In contrast, the study of Japanese atomic bomb survivors exposed briefly to radiation in 1945 found females to be nearly 3 times the radiation risk of lung cancer compared with males on a relative scale. For medical workers, there were no statistically significant radiation associations with leukemia excluding CLL, IHD or other specific causes of death. Combining these data with other cohorts within the MPS, such as nuclear power plant workers and nuclear submariners, will enable more precise estimates of radiation risks at relatively low cumulative doses.

Mortality from leukemia, cancer and heart disease among U.S. nuclear power plant workers, 1957–2011

Background The aim of the Million Person Study of Low-Dose Health Effects (MPS) is to examine the level of radiation risk for chronic exposures received gradually over time and not acutely as was the case for the Japanese atomic bomb survivors. Nuclear power plant (NPP) workers comprise nearly 15 percent of the MPS. Leukemia, selected cancers, Parkinson’s disease, ischemic heart disease (IHD) and other causes of death are evaluated. Methods and material The U.S. Nuclear Regulatory Commission’s Radiation Exposure Information and Reporting System (REIRS) and the Landauer, Inc. dosimetry databases identified 135,193 NPP workers first monitored 1957–1984. Annual personal dose equivalents [Hp(10)] were available for each worker. Radiation records from all places of employment were sought. Vital status was determined through 2011. Mean absorbed doses to red bone marrow (RBM), esophagus, lung, colon, brain and heart were estimated by adjusting the recorded Hp(10) for each worker by scaling factors, accounting for exposure geometry and energy of the incident gamma radiation. Standardized mortality ratios (SMR) were calculated. Radiation risks were estimated using Cox proportional hazards models. Results Nearly 50% of workers were employed for more than 20 years. The mean duration of follow-up was 30.2 y. Overall, 29,124 total deaths occurred, 296 from leukemia other than chronic lymphocytic leukemia (CLL), 3382 from lung cancer, 140 from Parkinson’s disease and 5410 from IHD. The mean dose to RBM was 37.9 mGy (maximum 1.0 Gy; percent >100 mGy was 9.2%), 43.2 mGy to lung, 43.7 mGy to colon, 33.2 mGy to brain, and 43.9 mGy to heart. The SMRs (95% CI) were 1.06 (0.94; 1.19) for leukemia other than CLL, 1.10 (1.07; 1.14) for lung cancer, 0.90 (0.76; 1.06) for Parkinson’s disease, and 0.80 (0.78; 0.82) for IHD. The excess relative risk (ERR) per 100 mGy for leukemia other than CLL was 0.15 (90% CI −0.001; 0.31). For all solid cancers the ERR per 100 mGy (95% CI) was 0.01 (–0.03; 0.05), for lung cancer −0.04 (–0.11; 0.02), for Parkinson’s disease 0.24 (–0.02; 0.50), and for IHD −0.01 (–0.06; 0.04). Conclusion Prolonged exposure to radiation increased the risk of leukemia other than CLL among NPP workers. There was little evidence for a radiation association for all solid cancers, lung cancer or ischemic heart disease. Increased precision will be forthcoming as the different cohorts within the MPS are combined, such as industrial radiographers and medical radiation workers who were assembled and evaluated in like manner.

BATAN PERSONAL DOSE EQUIVALENT Hp (10) AND Hp (3) INTERCOMPARISON RESULTS AT 2018 &amp; 2019

&lt;p&gt;One of the methods to ensure the quality of a laboratory is participating in an intercomparison activity. For the dosimetry laboratory network in Indonesia, the intercomparison activity is managed by the Secondary Standard Dosimetry Laboratory (SSDL) Jakarta. This paper describes the intercomparison among processing laboratory for personal dose equivalent H&lt;sub&gt;p&lt;/sub&gt;(10) and H&lt;sub&gt;p&lt;/sub&gt;(3) using thermoluminescent dosimeter (TLD)/films in 2018 &amp;amp; 2019. The SSDL Jakarta irradiated packages of participant's TLDs/films with Cs-137 and X-rays at a specific equivalent dose. The irradiated dosimeters were sent back to the participants by mail, and then the result was sent to the SSDL Jakarta for evaluation. The evaluation was carried out using the trumpet curve under the International Atomic Energy Agency (IAEA) publication. The results obtained for the 2018 intercomparison show the success rates of 98%, and 2% were outside the acceptable range, whereas for the 2019 Intercomparison, the success rates were 96% and 4% outside the acceptable range. The potential failure of reading the dose value was in the film dosimeter/badge. For those recent two years of intercomparison activities, the success rate was more than 95%. This result of the intercomparison activity showed the excellent quality of the personal dose equivalent H&lt;sub&gt;p&lt;/sub&gt;(10) and H&lt;sub&gt;p&lt;/sub&gt;(3) measurement in Indonesia.&lt;/p&gt;

Calculation of X-ray spectra characteristics and kerma to personal dose equivalent Hp(10) conversion coefficients: Experimental approach and Monte Carlo modeling

This work aims to establish some X-ray qualities recommended by the International Standard Organization (ISO) using the half-value layer (HVL) and Hp(10) dosimetry approaches. The HVL values of the following qualities N-60, N-80, N-100, N-150 and N-250 were determined using various attenuation layers. The obtained results were compared to those of reference X-ray beam qualities and a good agreement was found (difference less than 5% for all qualities). The GAMOS (Geant4-based Architecture for Medicine-Oriented Simulations) radiation transport Monte Carlo toolkit was employed to simulate the production of X-ray spectra. The characteristics HVLs, mean energy and the spectral resolution of simulated spectra have been calculated and turned out to be conform to the ISO reference ones (difference less than the limit allowed by ISO). Furthermore, the conversion coefficients from air kerma to personal dose equivalent for simulated and measured spectra were fairly similar (the maximum difference less than 4.2%).

Estimation of patients organ doses and staff exposure during bone scan examination

Radiopharmaceuticals are utilized in diagnostic nuclear medicine (NM) for a wide range of disorders. The purposes of the work are to assess patient organ doses in bone scan procedure with 99 m Tc-Methyl diphosphonate (MDP) and quantify the NM technologist exposure during bone scan procedure. Staff radiation exposure was determined using thermo-luminescent dosimeters (TLDs, Type LiF: Mg, Cu, P (GR200A)) were placed at the dominant hand. The TLD was calibrated to estimate the personal equivalent dose Hp (10) and Hp (0.07). The mean and range of the annual personal dose equivalent (Hp (10) and Hp (0.07) mSv) were 7.6 (3.2–9.1) and 30 (17.2–44), respectively. The patients' bladder retains an insignificant amount of the administered activity. Vast differences in patients’ and occupational doses were detected. Increasing staff awareness about radiation safety is recommended to enhance radiation protection and education unnecessary radiation doses. The personal doses equivalent are within the acceptable annual determined limits.

Characterization of a novel passive personal fast neutron dosimeter based on a CR-39 track detector in monochromatic neutron fields via Monte Carlo simulations and experiments

The response in terms of personal dose equivalent of a passive fast neutron dosimeter composed of a CR-39 detector coupled with a 1-cm-thick PMMA radiator is investigated in monochromatic neutron fields via simulations and experiments. In particular, the simulations were performed through the Monte Carlo FLUKA code (version 2011.2x.5), while the experimental fields were produced at the AMANDE facility (IRSN, France). The dosimeter response is studied with respect to both the energy and the angle of incidence of the radiation field on the device. The simulated response shows a quite stationary trend, that is, minimal variation across a wide energy range, also for different irradiation angles. The agreement between simulated and experimental responses indicates the simple and cheap dosimeter presented as promising for personal dosimetry applications in practical situations.