IAEA Recommendations Research Articles

Which Criteria Should We use to Determine an Adequate Number of Linear Accelerators in Emerging Economy Countries

In the age of limited resources, knowing the number of linear accelerators (LINACS) is paramount for designing and planning comprehensive coverage for a population. As important guidelines for the actual prediction of the number of LINACS, a wide range of directions are found in the literature. These guidelines vary depending on total population size, cancer incidence, cancer types, fractions per year, and machine workload. Knowing which guidelines to use, and which one fits the population's needs, is key to the best utilization of resources. In Oman, we have a stable population with minimal rates of immigration/emigration. The current needs of LINACS are met so we have a unique opportunity to test some of these guidelines and see which one most accurately predicts the correct number needed. The results should help emerging economies use a similar approach in estimating their needs. This study was conducted to estimate the demand for radiotherapy services needed in Oman taking into consideration the most common methods and recommendations available in the literature. The calculation methods analyzed: COCIR - targets a density of 7 radiation therapy units per million; ESTRO/QUARTS - 1 LINAC per 400 patients/year or 1 LINAC per 180,000 persons; and IAEA method that uses a combination of cancer incidence, number of treatment fractions per cancer type, and machine workload. The population demographics with cancer incidence were extracted from the Oman Cancer Registry data 2019 (total number of cases and cancer types). For the density of LINAC units per million population, we used the 2019 population of 4.603 million. For the workload calculation, we used 4 fractions/hour in an 8-hour shift and 248 working days. The calculations included the total number of cancer cases, average number of fractions per year, machine workload, rate of patients receiving radiotherapy per cancer type, the optimal number of fractions per treatment course, retreatment rate, and radiotherapy utilization rate per cancer type. Based on most frequent cancer incidence (1,437 cases), the total number of fractions per year is 22,920. The workload of machines was 7,936 fractions/year. If calculations included total number of cancer types (2,039) and average number of fractions per patient based on average number of fractions per cancer site, the total number of fractions is 27,715. If the reirradiation ratio included the number of fractions per year, a total of 34,644 (25% increase). For the COCIR, ESTRO/QUARTS, and IAEA recommendations, the range is 2.8 to 32 of required LINACS for adequate coverage in Oman (respectively 32; 4 to 25; and 2.8). The analysis of recommended guidelines for calculating the required number of LINACS in Oman showed a wide range. While in practice we know currently the number of LINACS required for our population is 5, for emerging economies 1 LINAC per 400 patients/year, or the IAEA calculation methods are the closest approximation to the actual needs.

Measurement of the delayed-neutron yield in the thermal neutron induced fission of 239Pu

This article presents an experimental effort to provide high-quality data to improve the evaluation of the 239Pu delayed neutron yield in the thermal energy range. The set-up is composed of a long counter with sixteen 3He tubes, a fast shutter system to produce irradiation cycles with short rising/falling times, and a miniature fission chamber containing 114μg of 239Pu. The whole system was installed in the PF1B experimental zone of the Institut Laue-Langevin, which provides a cold neutron beam. The repetition of irradiation/decay cycles enables to saturate the delayed neutron precursors and to measure their yield through the observed activity, shortly after the beam-stop. The innovation of our measurement technique relies on the clear distinction between prompt and delayed neutron counting, thanks to boron absorbers, without the necessity to move the sample. In such a way, it is possible to normalize the counting of delayed neutron emission to the one of total neutron emission, based on the well-known value of the prompt neutron multiplicity. The present work provides a delayed neutron yield value of vd = 0.642(5)%. The latter is in 1σ agreement with the IAEA recommendation of 0.628(38)%, with a strongly reduced uncertainty thanks to our normalization technique.

Methodology for Management and Physicochemical Control of the Cooling Water of the IPR-R1 Triga Nuclear Research Reactor


 
 
 
 The IPR-R1 Triga research reactor, located at CDTN (Nuclear Technology Development Center) in Brazil, is one of the oldest reactors in operation worldwide. The Brazilian Nuclear Energy Commission (Cnen) has granted a Permit for Permanent Operation license for the CDTN Triga reactor. This authorization includes some conditions to be settled within a period of up to two years, that is, until the end of 2019, which has not yet been carried out and is currently being prepared by CDTN. For this purpose, Project 0006.23 – Maintenance of Licensing of the IPR-R1 Triga Reactor was created in CDTN's Multiannual Program. In this project is included the Subproject: 6.23.3 – Preparation of the system to manage the aging of the IPR-R1 Triga reactor. Inserted in this context, the main objective of this paper is the proposal of good practices to be adopted in the future by CDTN, related to the Projects of Licensing and Aging of Triga reactor, for the management and physicochemical control of its cooling water, considering its electrical conductivity and pH, following IAEA recommendations. So, the present work is relevant, as it addresses a proposal for monitoring and controlling pH and electrical conductivity of the cooling water of Triga reactor. As a result of this proposal, the useful life of Triga reactor may be extended and there will be greater reliability and safety in its operation.
 
 
 
 

Features of Monitoring the Radioactive Situation in the Surface Air Layer and Precipitation near a Nuclear Power Plant

The influence of nuclear power plants on the population and agricultural fields located within a radius of 150 km from the nuclear power plant is considered. The features of monitoring the radioactive situation in the surface layer of the air have been studied. The volumetric activity of 137Cs near the nuclear power plant has been estimated. A sufficiently accurate way of placing monitoring installations has been determined (taking into account the direction of the winds, the distance to the nuclear power plant, and nearby settlements). It has been established that some radionuclides, which are currently poorly controlled, require additional measurements. A variant of replacing cuvettes with sides with universal collection tanks is proposed to provide more precise control. The placement of monitoring installations fully complies with the IAEA recommendations.

Manual on the proper use of meta-[211At] astato-benzylguanidine ([211At] MABG) injections in clinical trials for targeted alpha therapy (1st edition)

In this manuscript, we present the guideline for use of meta-[211At] astatobenzylguanidine ([211At] MABG), a newly introduced alpha emitting radiopharmaceutical to the up-coming World’s first clinical trial for targeted alpha therapy (TAT) at Fukushima Medical University in Japan, focusing on radiation safety issues in Japan. This guideline was prepared based on a study supported by the Ministry of Health, Labour, and Welfare, and approved by the Japanese Society of Nuclear Medicine on Oct. 5th, 2021. The study showed that patients receiving [211At] MABG do not need to be admitted to a radiotherapy room and that TAT using [211At] MABG is possible on an outpatient basis. The radiation exposure from the patient is within the safety standards of the ICRP and IAEA recommendations for the general public and caregivers or patient’s family members. In this guideline, the following contents are also included: precautions for patients and their families, safety management associated with the use of [211At] MABG, education and training, and disposal of medical radioactive contaminants. TAT using [211At] MABG in Japan should be carried out according to this guideline. Although this guideline is based on the medical environment and laws and regulations in Japan, the issues for radiation protection and evaluation methodology presented in this guideline are useful and internationally acceptable as well.

Radiotherapy and cancer status in Latin America: economic analysis of investment opportunities up to 2030

Timely access to radiotherapy treatments for cancer in Latin America is hindered by substantial delays in investment. We herein report on the current incidence of the ten most frequent malignancies and on radiotherapy-related logistics across Latin America with the objective of identifying resource gaps and facilitate the planning of health-care investments up to 2030. Data were collected from the International Atomic Energy Agency's (IAEA) Directory of Radiotherapy Centers and matched to open-source databases and individual surveys sent to national scientific societies in participant countries (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Mexico, Paraguay, Peru, Uruguay, and Venezuela). Demographic, economic, and epidemiological data were gathered from the World Bank and the Global Cancer Observatory registries. The incidence rates of the ten most common cancers treated with radiotherapy in each country were multiplied by the respective radiotherapy use rate according to the IAEA's Time-Driven Activity-Based-Costing model. Country-specific adjustments were made and the following assumptions were factored for the analysis: 240 working days, 60 patients treated per teletherapy unit per day, and 25 external beam radiotherapy fractions required per diagnosis at a cost of US$ 1703·75 or equivalent per full treatment, and four brachytherapy fractions for cervical (75% of total) and endometrial (27%) cancer and one boost fraction for prostate cancer (5%) diagnosis, at a cost of US$ 1426·40 per treatment. These values were adopted from India (for cervix cancer data) and Spain (endometrial cancer data), which are countries with a cancer incidence profile similar to that of Latin America. The prostate brachytherapy use rate was adopted from recently published US data. Human resource requirements were estimated according with the observed annual cancer incidence, keeping with IAEA's recommendations. 10-year incidence and costs projections were calculated according to the estimated demography dynamics and time value of money equation for each country for the period 2020-30. Current and projected cancer incidences and radiotherapy, personnel, and logistic requirements are reported through absolute numeric differences and mean values. Potentially saved lives (equivalent to 50% of newly included patients after increasing radiotherapy capacities to recommended levels) and monetary return, assumed as a mean regional monthly wage multiplied by the rescued life-years, are also reported. Information concerning the 11 most populous countries in Latin America was obtained. As of 2020, a population of 557 213 447 individuals was recorded, accounting for 85% of the Latin American inhabitants and projected to increase to 772 038 620 (an increase of 214 825 173) by 2030. The 2020 overall cancer incidence was 1 055 892 cases and the mean 2020 incidence per country was 95 990 (SD 135 013). The 10-year projection was of 1 460 154 new cases with a mean of 132 741 (SD 188 832) per country, highlighting the high variability in needs across the region. Overall external beam radiotherapy use rate was estimated for 663 236 annual new cases in 2020, versus 916 592 annual new cases by 2030, and overall brachytherapy use was estimated for 90 428 annual new cases in 2020 and 125 152 annual new cases by 2030. The 2020 regional availability of treatment fractions was 11 822 400 for external beam radiotherapy and 216 960 for brachytherapy. Conversely, the 2020 required number of fractions was 13 241 088 (+12·2%) for external beam radiotherapy and 361 672 (+66·7%) for brachytherapy; and the projected required number of fractions in 2030 is 18 324 720 (+55·0%) for external beam radiotherapy and 500 744 (+130·8%) for brachytherapy. If the projected demand was to be covered, an additional 181 622 lives could potentially be saved by 2030, accounting for a 2-year total financial return of US$ 1 963 776 038·20, assuming 50% of additionally treated patients will be reincorporated to the economically active population. Bridging the gap in radiotherapy up to 2030 will save lives and reduce the financial toxicity of cancer management in Latin America. Governmental and private investment in radiotherapy is urgently required to shorten access disparities and reach these goals. None.

X-Ray Dose Audit and Potential Local Diagnostic Reference Levels in Select Hospitals In Kaduna State, Nigeria


 
 
 
 
 Background: Dosimetry in diagnostic radiology is fundamental to providing information to practitioners regarding the level of their doses and to ensure adequate optimization of the protection of patients presenting for radiological examinations. The introduction and implementation of diagnostic reference levels (DRLs) in diagnostic radiology has proven to be a potent tool for quality control and dose reduction. This has not been comprehensively addressed in Nigeria.
 Objective: To carryout dose audit of patients presenting for common radiographic projections in select hospitals in Kaduna State, Nigeria.
 Methodology: Thermoluminescent dosimeters (TLDs) were used to measure entrance surface dose (ESD) on 420 randomly selected adult patients presenting for x-ray examination of the chest PA/Lateral, skull PA/Lateral, lumbar spine AP/Lateral, abdomen and pelvic AP, respectively. Results were compared with existing literature.
 Results: The range of the mean ESD determined for the study population on various x-ray examinations were: chest PA (0.44 – 0.9 mGy), and lateral (0.9 – 1.5 mGy); skull PA (2.0 – 4.7 mGy), and lateral (1.7 – 3.4 mGy); lumbar spine AP (3.4 -7.8 mGy), and lateral (6.8 –11.3 mGy); abdomen AP (3.6 – 6.2 mGy); and pelvic AP (2.4 – 6.9 mGy). Comparison showed dose levels were below IAEA recommendations.
 Conclusion: In the absence of arbitrary high doses, practice is generally safe and will not result in unwarranted hazards to the patients.
 
 
 
 

X-Ray Dose Audit and Potential Local Diagnostic Reference Levels in Select Hospitals In Kaduna State, Nigeria


 
 
 
 
 Background: Dosimetry in diagnostic radiology is fundamental to providing information to practitioners regarding the level of their doses and to ensure adequate optimization of the protection of patients presenting for radiological examinations. The introduction and implementation of diagnostic reference levels (DRLs) in diagnostic radiology has proven to be a potent tool for quality control and dose reduction. This has not been comprehensively addressed in Nigeria.
 Objective: To carryout dose audit of patients presenting for common radiographic projections in select hospitals in Kaduna State, Nigeria.
 Methodology: Thermoluminescent dosimeters (TLDs) were used to measure entrance surface dose (ESD) on 420 randomly selected adult patients presenting for x-ray examination of the chest PA/Lateral, skull PA/Lateral, lumbar spine AP/Lateral, abdomen and pelvic AP, respectively. Results were compared with existing literature.
 Results: The range of the mean ESD determined for the study population on various x-ray examinations were: chest PA (0.44 – 0.9 mGy), and lateral (0.9 – 1.5 mGy); skull PA (2.0 – 4.7 mGy), and lateral (1.7 – 3.4 mGy); lumbar spine AP (3.4 -7.8 mGy), and lateral (6.8 –11.3 mGy); abdomen AP (3.6 – 6.2 mGy); and pelvic AP (2.4 – 6.9 mGy). Comparison showed dose levels were below IAEA recommendations.
 Conclusion: In the absence of arbitrary high doses, practice is generally safe and will not result in unwarranted hazards to the patients.
 
 
 
 

РАДИАЦИОННО-ГИГИЕНИЧЕСКИЕ ИССЛЕДОВАНИЯ ЭКСПЕРИМЕНТАЛЬНОГО ПРОИЗВОДСТВА СМЕШАННОГО НИТРИДНОГО УРАН-ПЛУТОНИЕВОГО ТОПЛИВА НА АО «СХК». Часть 2: Дозы и риски

Purpose: Assessment of the compliance of the radiation protection of workers at the complex experimental installations of JSC SChC with the requirements of the Russian radiation safety standards NRB-99/2009 to limit the generalized risk of potential exposure and the IAEA recommendations for not exceeding the control level of the minimum significant radiation risk. Materials and methods: The results of radiation-hygienic investigations of radiation exposure factors affecting workers involved in the manufacture of mixed uranium-plutonium nitride (MUPN) fuel at the complex experimental installations of JSC SChC are used as the input data for the preliminary assessment of radiation doses to workers. The models for assessment of radiation risk of potential exposure have been developed in accordance with the recommendations of the ICRP and the IAEA. Results: Preliminary estimates of the doses of external gamma-neutron (2.5 ± 0.5 mSv / year) and internal exposure of workers (~1 mSv/year1) are related to the current levels of exposure of workers of complex experimental installations. These levels are the result of exposure to ionizing radiation sources associated both with the development of new technologies and with residual radioactive contamination resulting from previous activities not related to the manufacture of MUPN fuel. The presented dose estimates are related to the use of raw materials that have undergone deep preliminary purification from radiogenic impurities. When irradiated nuclear materials are used as raw materials, the levels of gamma-neutron exposure to workers will be significantly higher. The maximum increase in the generalized risk of potential exposure due to annual exposure is estimated for women aged 18 years at the beginning of exposure, for which the increase in this risk is 1.45 × 10-4 year-1, which is 1.37 times lower than the limit established by the Russian radiation safety standards NRB-99/2009: 2 × 10-4 year-1. All predicted values of the lifetime attributable fraction of radiation (LARF) in mortality from malignant neoplasms are significantly less than the control level of the minimum significant risk recommended by the IAEA (LARF = 5 %), and the maximum value of LARF = 2.8 % is achieved for women aged 18 years at the beginning of exposure. Conclusion: Restrictions on the radiation risks of potential exposure, established by NRB-99/2009, as well as those recommended by the IAEA for not exceeding the reference level of the minimum significant risk, are met with a large reserve. The results obtained and the developed methods will be used to ensure the radiation safety of workers during the transition from experimental installations to pilot industrial implementation of the technology for the production of MUPN fuel.

Ретроспективная оценка тяжести отдалённых лучевых повреждений онкологических пациентов методом цитогенетического обследования

This paper presents the results of the study of long-term effect of radiation therapy on patients with different types of cancer. The aim of the retrospective study was to evaluate effect of external beam radiation therapy (EBRT) for improving rehabilitation effectiveness. To estimate the effect a cytogenetic analysis of chromosomal aberrations in peripheral blood lymphocytes was performed. The group included patients for whom clarification, confirmation or refutation of the total focal dose (TFD) indicated in the epicrisis after EBRT was required. A group of 25 patients (5 males and 20 females) was examined. The patients had different types of cancer: Hodgkin’s lymphoma, cancer of breast and prostate glands, cervical and uterine cancers, bone cancer and multisite cancer. All examined patients underwent rehabilitation in the department of surgical and conservative treatment of radiation Injuries of A. Tsyb MRRC. For examination patient’s blood lymphocytes were stained followed by fluorescence or light microscopy to image first mitosis cells. To detect aberrations chromosome preparations with stained chromosomes 2, 4, and 12 were subjected to FISH analysis. Chromosomal aberration analysis was also used for dose assessment in accordance with IAEA recommendations. As a result, it was shown that the individual response of patients varies significantly under irradiation schemes comparable in terms of total dose and fractionation. A significant role is played by the factor of the time interval between the end of EBRT and the cytogenetic analysis (∆T). There was a clear excess of the observed frequency of aberrations in the first decade after EBRT compared with the subsequent time. The work did not reveal any dependence between the total frequency of aberrations, as well as its components, on the type of cancer disease. According to the preliminary conclusion, there is a basis for applying obtained estimates of the dose coefficient for retrospective biodosimetry of patients with the diseases listed in the group. The revealed patterns of chromosomal damage induction in blood lymphocytes of cancer patients prove the need for a personalized approach to planning and implementing a radical course of therapy in order to increase its effectiveness and prevent side effects.

ГАРМОНИЗАЦИЯ ЗАКОНОДАТЕЛЬНЫХ АКТОВ РОССИЙСКОЙ ФЕДЕРАЦИИ С СОВРЕМЕННЫМИ МЕЖДУНАРОДНЫМИ РЕКОМЕНДАЦИЯМИ

Purpose: Harmonization of the Russian Federation legislation with current international recommendations
 Results: The concept of the radiation safety system has been significantly modified by recommendations of ICRP (2007) and IAEA (2014). An analysis of existing international regulatory framework for radiation safety allowed to identify the main provisions to be implemented in the Russian legal and regulatory framework. It’s showed that the current Federal Law of 09.01.1996 No. 3-FZ «On Radiation Safety of Population» must be ultimately revised to be harmonized with international documents. General approaches to legal regulation of radiation safety should be essentially modified to create a strong relationship between this law and other regulatory and legal documents in force in the Russian Federation.
 Conclusion: An article-by-article analysis of the current Federal Law of 09.01.1996 No. 3-FZ «On Radiation Safety of Population « showed the need to modify 22 existing articles and add 12 new articles in order to harmonize it with international documents. Given such a large volume of modification it is advisable to pass a new law with simultaneous abolition of the current federal law. A new name has been proposed: Federal Law of the Russian Federation «On Radiation Safety in the Russian Federation». 
 The enactment of the Federal Law of the Russian Federation «On Radiation Safety in the Russian Federation» with the main by-laws approved by the Russian Federation Government – «Radiation Safety Standards» and «Basic Rules for Ensuring Radiation Safety» – will allow to establish an actual regulatory framework for ensuring radiation safety of personnel and population in Russia.

Manual on the proper use of sodium astatide ([211At]NaAt) injections in clinical trials for targeted alpha therapy (1st edition)

We present the guideline for use of [211At] sodium astatide (NaAt) for targeted alpha therapy in clinical trials on the basis of radiation safety issues in Japan. This guideline was prepared by a study supported by the Ministry of Health, Labour, and Welfare, and approved by the Japanese Society of Nuclear Medicine on 8th Feb, 2021. The study showed that patients receiving [211At]NaAt do not need to be admitted to a radiotherapy room and outpatient treatment is possible. The radiation exposure from the patient is within the safety standards of the ICRP and IAEA recommendations for the general public and caregivers. Precautions for patients and their families, safety management associated with the use of [211At]NaAt, education and training, and disposal of medical radioactive contaminants are also included in this guideline. Treatment using [211At]NaAt in Japan should be carried out according to this guideline. Although this guideline is applied in Japan, the issues for radiation protection and evaluation methodology shown here are considered internationally useful as well.

ОПЕРАТИВНАЯ ОЦЕНКА ЗНАЧЕНИЙ ДОЗЫ НАД ЩИТОВИДНОЙ ЖЕЛЕЗОЙ, СООТВЕТСТВУЮЩИХ ОПРЕДЕЛЕННЫМ УРОВНЯМ ПОГЛОЩЕННОЙ ДОЗЫ В ЩИТОВИДНОЙ ЖЕЛЕЗЕ, ДЛЯ НАСЕЛЕНИЯ В РАННИЙ ПЕРИОД ПОСЛЕ КРУПНОЙ РАДИАЦИОННОЙ АВАРИИ

In case of a large radiation accident at the nuclear power station the most important radiation hazard for the public is internal exposure to the thyroid from radioiodine. The IAEA standard published in 2013 and accounting the experience of the Chernobyl and Fukushima accidents, recommends that, in the first 1-6 days after an inhalation intake of radioiodine the exposure rate over the thyroid be measured for the public and be guided by the following operational criteria: (a) 0.5 μSv · h-1 for children under the age of 7 years, and (b) 2 μSv ·h-1 for children over 7 years and adults. These operational criteria are indicative estimates corresponding to the dose range 100–200 mGy in the thyroid for all age groups. However, a wider range of thyroid doses and a more detailed breakdown of children into five age groups according to the recommendations of the ICRP are of interest.
 The purpose of this paper is to develop a method for estimating the values of the measured exposure rate over the thyroid corresponding to certain levels of the absorbed dose in the thyroid for members of the public of different ages for various conditions of inhalation of radioiodine intake and times of measurement in the early period after a radiation accident.
 According to the method developed in the paper for the committed absorbed dose 100-200 mGy in the thyroid the exposure rates over the thyroid were calculated depending upon the time of inhalation intake after the accident and the time span between the moment of intake and the moment of measurement, which were equal to: 0.6– 4 μSv ·h-1 - for children of 1 year and 4–27 μSv · h-1 – for adults. These values are significantly higher than those recommended by the IAEA Standard 0.5 μSv · h-1 and 2 μSv · h-1, respectively. It is important to stress that the IAEA recommendations provide conservative estimates of the measured exposure rate over the thyroid in order to maximize the coverage of critical group of the public for further dosimetric and medical examination. For example, for some options of the time of radioiodine inhalation intake and the time of measurement, the IAEA recommended the values of the exposure rate over the thyroid that can lead to an overestimation of the absorbed dose in the thyroid gland by a factor of up to 10.

Study of the upper energy limit of useful epithermal neutrons for Boron Neutron Capture Therapy in different tissues

In Boron Neutron Capture Therapy (BNCT), the IAEA recommendations limit the epithermal range to 10 keV. Few works have shown the possibility to increase this limit. In particular, in a previous work we showed this possibility by means of simulations of the dose on a simple phantom of a 4-component ICRU tissue. This possible increment is very relevant for the future accelerator-based neutron sources for BNCT. The present work is based on more realistic MCNP6.2 simulations at neck, brain and abdomen. Several parameters and Figures of Merit have been evaluated for different beam apertures and beam divergences. The results show that neutrons above 10 keV can be useful for BNCT. The exact limit of the epithermal range depends on the location of the tumor.

Optimized beam shaping assembly for a 2.1-MeV proton-accelerator-based neutron source for boron neutron capture therapy

Boron Neutron Capture Therapy (BNCT) is facing a new era where different projects based on accelerators instead of reactors are under development. The new facilities can be placed at hospitals and will increase the number of clinical trials. The therapeutic effect of BNCT can be improved if a optimized epithermal neutron spectrum is obtained, for which the beam shape assembly is a key ingredient. In this paper we propose an optimal beam shaping assembly suited for an affordable low energy accelerator. The beam obtained with the device proposed accomplishes all the IAEA recommendations for proton energies between 2.0 and 2.1 MeV. In addition, there is an overall improvement of the figures of merit with respect to BNCT facilities and previous proposals of new accelerator-based facilities.

Accumulations of artificial radionuclides 137Cs and 239+240Pu in anchovy from the Korean seas

We investigated the accumulation patterns of the artificial radionuclides 137Cs and 239+240Pu in anchovy – categorized into four groups by size– from Korean seas. The activities of 137Cs and 239+240Pu were in the ranges of 74–137 mBq kg−1 and 0.27–3.21 mBq kg−1, respectively. They generally increased with increasing size (except for 239+240Pu in large anchovy), indicating radionuclide accumulation by seawater uptake through respiratory and/or higher feed capacity as a manifestation of growth. However, the activity of 239+240Pu decreased sharply in large anchovy. The calculated concentration factors (CFs) of 137Cs in anchovy were 10.9–20.2, which are an order of magnitude lower than those in other marine organisms. However, the CFs of 239+240Pu in adult anchovy were 14.0–162.8, which are significantly higher than those in other fishes and comparable (or even higher) to the IAEA recommendation values. The annual effective dose (AED) rates of 137Cs and 239+240Pu for anchovy consumption (per person) in South Korea were estimated to be 3.7 × 10−6–6.9 × 10−6 mSv yr−1 and 0.26 × 10−6–3.10 × 10−6 mSv yr−1, respectively. The AED from anchovy consumption is insignificant relative to that of natural radionuclides.

A Comprehensive Survey of Proton Beam Therapy Research and Development in Iran

Purpose: Proton Beam Therapy (PBT) is an emerging radiotherapy technique using beams of proton to treat cancer. As the first report addressing the topic, the principal aim is to highlight the present status of PBT research and development in Iran as a developing country. Materials and Methods: To do so, the demand for PBT in Iran and Iran National Ion Therapy Center (IRNitc) was investigated and introduced. Then, Scopus and PubMed were searched for studies that dealt with PBT research in Iran and subsequently 6 major subfields of interest were identified. Furthermore, international collaborations were extracted from the bibliographic data. To combine both research and development sides, a SWOT analysis was performed through collecting viewpoints of 48 radiotherapy experts about PBT, and then strengths, weaknesses, opportunities, and threats of it were examined. Results: Iran contributes to approximately 1% of global PBT sciences. Proton dose calculation using Monte Carlo simulation is the dominant subject of interest for Iranian researchers. Italy is recognized as the major foreign partner in PBT researches. Clinical advantages over conventional radiotherapy modalities are the main strength of PBT development in Iran while the high installation cost remains the most weakness. Finally, 10 general considerations for the launching of a PBT facility in Iran were presented based upon both Iranian experts’ viewpoints and IAEA recommendations. Conclusion: This research reveals that while PBT research and development in Iran are still in their infancy, there are promising trends in both the research and development sides of PBT.

Precision measurement of relative [formula omitted]-ray intensities from the decay of 61Cu

A discrepancy, well outside reported uncertainties, has been observed between the accepted and measured values of the intensity ratio of the two strongest γ rays following 61Cu β+ decay. This discrepancy has significant impact since the natNi(d,x)61Cu reaction has historically been one of only a few IAEA recommendations for use as a deuteron flux monitor and a considerable number of published cross sections measured in ratio to that beam monitor cross section may depend on the choice of either the first or second strongest γ ray in those calculations. To determine the magnitude of this error most precisely, over a hundred separate measurements of the 283 keV to 656 keV γ-ray emission ratio were collected from seven experiments and a variety of detectors and detection geometries. A weighted average of all these measurements indicates an error in the value listed in the Nuclear Data Sheets of 11% in either the primary or second-highest intensity γ ray of 61Cu, potentially introducing an 11% error in 61Cu production cross section measurements, cross sections using nickel activation as a deuteron beam current monitor, or in dose rates when 61Cu is used in nuclear medicine. General agreement with the Data Sheets with ten other intensity ratios suggests the most probable error is in the secondary (656 keV) emission, which accordingly should be updated from 10.8% to 9.69%.

Comparative Studies of Absolute Dose in Water Phantom, Solid Water Phantom and MatriXX with MULTICube Phantom

Introduction: Radiotherapy is one of the important treatment modalities in cancer treatment. To maintain the treatment procedure accuracy, the phantom is an essential tool for absolute dosimetry conformation and Quality Assurance routine cheek up. This work aims to study the absorbed dose of various phantoms and hence to make a comparison of the result with the IAEA recommendation (TRS 398) for daily QA of Linac. Materials and Methods: The experiment has been done at the Institute of Nuclear Medical Physics (INMP), AERE, Savar, Dhaka, under the Bangladesh Atomic Energy Commission. For external beam radiation, 6 MV and 15 MV photon beams of Varian Clinac iX Linear Accelerator (Linac) were used. One dimensional (1D) water phantom, solid water phantom, and MatriXX with MULTICube phantom and associate accessories were used to experiment. Results: We have measured and compared the absorbed dose data of the phantoms. The variation of sold water phantom from the 1D water phantom is +2.8% at 6 MV and +3.5% at 15 MV. The variation MatriXX with MULTIcube phantom from the 1D water phantom is +8.0% at 6 MV and +3.2% at 15 MV. This study revealed that the 1D water phantom was the best absolute dose conformation among the other phantoms and the deviation was within the acceptable limit (±5%), except MatriXX with MULTICube Phantom for low energy beam (8%). Conclusion: It was observed that the accuracy of dose estimation was better in the 1D water phantom rather than the other two. It is also known that the 1D water phantom is low cost but needs a long time to set up for the experimental arrangement. Solid water or MatriXX with MULTICube phantom can be used to overcome this problem, which takes only a few minutes for setup and is comparatively faster than 1D water phantom.

Radioactive Waste Classification in the Russian Federation and the USA

Approaches to the system of radioactive waste classification in the USA and the Russian Federation were considered. The variety of sources of radioactive waste generation is shown. The necessity of radioactive waste classification and characterization is justified. The main problems in the field of radioactive waste management in two countries are outlined, the ways of development of two systems to improve the activity of radioactive waste management are presented. The basic principles of assessing the sustainability in the field of radioactive waste management INPRO and reducing the potential exposure of personnel and population of ALARA are shown. Comparisons of two national systems of radioactive waste classification were made and compliance with the IAEA recommendations was assessed.