16 research outputs found

    РЕАКТОРНЫЕ И ПОСЛЕРЕАКТОРНЫЕ ИСПЫТАНИЯ И ИССЛЕДОВАНИЯ НА БЫСТРЫХ КРИТИЧЕСКИХ СБОРКАХ ВЫСОКОПЛОТНОГО НИЗКООБОГАЩЕННОГО УРАН-ЦИРКОНИЕВОГО КАРБОНИТРИДНОГО ТОПЛИВА

    Get PDF
    UZrCN fuel is a high-density, high-temperature fuel that has potential for application in different type reactors. In the past, reactor tests using UZrCN HEU (96% U-235) fuel have been performed to low burnup. However, reactor-testing data are still needed at high burnup to confirm the optimal performance of this-type fuel. The SM-3 research reactor, which is a high-flux reactor located at the State Scientific Center – Research Institute of Atomic Reactors, Dimitrovgrad, Russia, will be used to test a UZrCN LEU (19.73% U-235) fuel to ~40% of burnup. The fuel will then be examined to determine its performance during irradiation.On the “Giacint” and “Kristal” critical facilities located at the Joint Institute for Power and Nuclear Research – SOSNY of the National Academy of Sciences of Belarus, Minsk, Belarus, criticality experiments on multiplying systems modeling physical features of cores with UZrCN LEU (19.75% U-235) fuel have been prepared for use in works on fast reactors with gaseous and liquid-metal coolants. Critical assemblies represent uniform hexagonal lattices of fuel assemblies, each of which consists of 7 fuel rods and has no clad. The active fuel length is 500 mm. Clad material is stainless steel or Nb. Three types of fuel assemblies with different matrix material (air, aluminum and lead) are investigated. These are side radial, top and bottom reflectors – beryllium (internal layer) and stainless steel (external layer).This article desribes the design of the experiment that will be performed in the SM-3 reactor and discusses the results of different calculations that have been performed to show that the experiment design will meet all objectives. The description of construction and composition of critical assemblies with UZrCN fuel and the calculation results are also presented. Топливо UZrCN представляет собой высокоплотное высокотемпературное топливо, которое может применяться в реакторах различных типов. В прошлом реакторные испытания ВОУ (96% U-235) UzrCN-топлива были выполнены только с низким выгоранием. Вместе с тем данные реакторных испытаний необходимы при высоком выгорании для подтверждения оптимальных характеристик этого типа топлива. Высокопоточный исследовательский реактор СМ-3, расположенный в Государственном научном центре – Научно-исследовательский институт атомных реакторов (г. Димитровград, Россия), будет использоваться для испытания НОУ (19,73% U-235) UzrCN-топлива до ~40 % выгорания. Затем топливо будет исследоваться для определения его характеристик после облучения.На критических стендах «Гиацинт» и «Кристал» в Объединенном институте энергетических и ядерных исследований – Сосны Национальной академии наук Беларуси (г. Минск, Беларусь) осуществляется подготовка к экспериментам по критичности на размножающих системах, моделирующих физические особенности активных зон с НОУ (19,75% U-235) UzrCN-топливом для использования в работах по новому поколению быстрых реакторов с газообразными и жидкометаллическими теплоносителями. Критические сборки представляют собой однородные гексагональные решетки топливных сборок, каждая из которых состоит из семи топливных стержней и не имеет оболочки. Длина активной части топливного стержня составляет 500 мм. Материал оболочки – нержавеющая сталь или ниобий. Будут исследованы три типа топливных сборок с различным материалом матрицы в них (воздух, алюминий и свинец). Боковой радиальный, верхние и нижние отражатели – бериллий (внутренний слой) и нержавеющая сталь (внешний слой).В настоящей статье описываются проектные данные эксперимента, который будет осуществлен на реакторе СМ-3, и обсуждаются результаты расчетов, призванные показать, что эксперимент будет отвечать всем поставленным целям. Также представлены описания конструкции и состава критических сборок с топливом UZrCN и результаты их расчетов.

    Comparison of duke activity status index with cardiopulmonary exercise testing in cancer patients

    No full text
    Purpose: The Duke Activity Status Index (DASI), a patient-administered questionnaire, is used to quantify functional capacity in patients undergoing cancer surgery. Methods: This retrospective cohort study assessed whether the DASI was accurate in predicting peak oxygen consumption (pVO2) that was objectively measured using cardiopulmonary exercise testing (CPET) in 43 consecutive patients scheduled for elective major cancer surgery at a tertiary cancer centre. The primary outcome measured the limits of agreement between DASI-predicted pVO2 and actual measured pVO2. Results: The study population was elderly (median 63 years, interquartile range 18), 58% were male, with the majority having intraabdominal cancer surgery. Although the DASI scores were statistically related to the measured pVO2 (N = 43, adjusted R2 = 0.20, p = 0.002), both the bias (8 ml kg− 1 min− 1) and 95% limits of agreement (19.5 to − 3.4 ml kg− 1 min− 1) between the predicted and measured pVO2 were large. Using some of the individual components, recalibrating the intercept and regression coefficient of the total DASI score did not substantially improve its ability to predict the measured pVO2. Conclusion: In summary, both the limits of agreement and bias between the measured and DASI-predicted pVO2 were substantial. The DASI-predicted pVO2 based on patient’s assessment of their functional status could not be considered a reliable surrogate of measured pVO2 during CPET for the population of patients pending major cancer surgery and cannot, therefore, be used as a triage tool for referral to CPET centres for objective risk assessment

    Scientific, technical and organizational aspects of the spent fuel removal from nuclear research reactor of Institute for Nuclear Research, National Academy of Sciences of Ukraine

    No full text
    Supporting the global threat reduction initiative (GTRI) Ukraine has implemented the removal of the major part of HEU spent nuclear fuel from the WWR-M research reactor of Institute for nuclear research of NAS of Ukraine to Russian Federation for further processing in "MAYAK" company

    A cross-sectional survey of Australian anesthetists’ and surgeons’ perceptions of preoperative risk stratification and prehabilitation

    No full text
    Purpose: Preoperative fitness training has been listed as a top ten research priority in anesthesia. We aimed to capture the current practice patterns and perspectives of anesthetists and colorectal surgeons in Australia and New Zealand regarding preoperative risk stratification and prehabilitation to provide a basis for implementation research. Methods: During 2016, we separately surveyed fellows of the Australian and New Zealand College of Anaesthetists (ANZCA) and members of the Colorectal Society of Surgeons in Australia and New Zealand (CSSANZ). Our outcome measures investigated the responders’ demographics, practice patterns, and perspectives. Practice patterns examined preoperative assessment and prehabilitation utilizing exercise, hematinic, and nutrition optimization. Results: We received 155 responses from anesthetists and 71 responses from colorectal surgeons. We found that both specialty groups recognized that functional capacity was linked to postoperative outcome; however, fewer agreed that robust evidence exists for prehabilitation. Prehabilitation in routine practice remains low, with significant potential for expansion. The majority of anesthetists do not believe their patients are adequately risk stratified before surgery, and most of their colorectal colleagues are amenable to delaying surgery for at least an additional two weeks. Two-thirds of anesthetists did not use cardiopulmonary exercise testing as they lacked access. Hematinic and nutritional assessment and optimization is less frequently performed by anesthetists compared with their colorectal colleagues. Conclusions: An unrecognized potential window for prehabilitation exists in the two to four weeks following cancer diagnosis. Early referral, larger multi-centre studies focusing on long-term outcomes, and further implementation research are required
    corecore