Search for the Neutrino Magnetic Moment in the Non-Equilibrium Reactor Antineutrino Energy Spectrum

We study the time evolution of the typical nuclear reactor antineutrino energy spectrum during reactor ON period and the decay of the residual antineutrino spectrum after reactor is stopped. We find that relevant variations of the soft recoil electron spectra produced via weak and magnetic ${\widetilde {\nu}}_{e},e$ scattering process can play a signigicant role in the current and planned searches for the neutrino magnetic moment at reactors.Comment: 4 pages LaTeX 2.09. 4 PS figures. Resume of seminar talks given at Kurchatov Institute, March 1999

The calculation of the campaign of reactor RITM200

In this paper, the campaign of RITM-200 reactor was calculated. The duration of the campaign was determined taking the net capacity factor into consideration. The calculated duration concurred with the known data. The neutron parameters were calculated using the effective temperature method. The presence of burnable absorber rods was taken into account. Their effect was considered using the diffusional approach. The iterative computations were used to finally determine the temperature of the neutron gas. At the end, the reactivity curve displaying different effects inside fuel, namely fuel and gadolinium burn-out, the poisoning and slagging was drawn

Scenarios for a worldwide deployment of nuclear energy production

Intensive worldwide deployment of nuclear power could prove necessary to mitigate global warming and fossil fuel shortages while still satisfying a growing demand for energy. We present scenarios for such deployment and bring to light the constraints, such as the availability of fissile matter and the build up of Plutonium stockpiles according to the reactor types considered. Pending the availability of reactors able to breed their fuel, a fleet of 2nd ant 3rd generation light water reactors will have to be built. These can ensure a growth of nuclear power for the coming 20 to 25 years and the transition to sustainable 4th generation nuclear reactors. We show that at least one comprehensive and balanced solution can be found, which reconciles fuel cycle closing, non-depletion of natural resources, reduced long lived waste production, and the option to stop or restart nuclear power rapidly. It rests on the combination of light water reactors and converter reactors needed to incinerate Plutonium and produce Uranium-233, leading to a reactor fleet widely based on the Thorium-Uranium-233 fuel cycle. The flexibility of this solution and its naturally reduced long lived waste production makes it appear optimal in view of sustainable, intensive nuclear power generation

Unmovable Detection Unit of the Thermal Neutron Flux in the Source Range of the Reactor

This paper presents the results of theoretical and experimental research of the new unmovable detection unit of the thermal neutron flux in the source range of the reactor. The design features and the main parameters of this unit are also shown

Concrete decontamination by Electro-Hydraulic Scabbling (EHS)

EHS is being developed for decontaminating concrete structures from radionuclides, organic substances, and hazardous metals. EHS involves the generation of powerful shock waves and intense cavitation by a strong pulsed electric discharge in a water layer at the concrete surface; high impulse pressure results in stresses which crack and peel off a concrete layer of controllable thickness. Scabbling produces contaminated debris of relatively small volume which can be easily removed, leaving clean bulk concrete. Objective of Phase I was to prove the technical feasibility of EH for controlled scabbling and decontamination of concrete. Phase I is complete

Исследование параметрических взаимодействий при регулировании ядерного реактора с обратной связью

This article considers the principal theoretical possibility of regulating a nuclear power reactor under changing operating modes conditions when external periodic disturbances take place in conditions of changing the operating mode. By the external periodic perturbation a downward change in the conditions of the heat sink was meant. The magnitude of the changes was preliminarily calculated in such a way that the operating conditions of the power plant did not exceed the boundaries of the safe operation zone of the reactor. In the case of approaching the operation parameters to the critical ones, the heat sink was increased until the working conditions returned to their previous state. In this work the amplitude frequency response of a non-linearly enhanced system in the nuclear power plant operating conditions when non-linearly reacting to external periodic influences has been studied. The external cyclic disturbances effect produced on the reactor that initially existed under stationary operating conditions has been considered. The research was carried out by numerical simulation of the competition between processes occurring in a nuclear power plant and determined by the system’s reaction time and relaxation time while responding to periodic external influences. Calculations of the relaxation time dependence on the fixed frequency-revealing external influence’s temperature are presented. Also, the relaxation time dependence on the frequency of external influence at a fixed temperature for systems with various relaxation periods was calculated. It is determined that when the dependence between system temperature and the external influence time is calculated, there exists a wide range of possible frequency control. To evaluate the behavior of a nuclear power reactor under conditions of operating modes changes, a fundamental physical mathematical model of the reactor’s state under external harmonic influence is presented. It is based on the nonlinear Riccati equation. The external harmonic effect was simulated by changing the heat supply and heat removal conditions near the critical point.Рассмотрена принципиальная теоретическая возможность регулирования ядерного энергетического реактора, находящегося под воздействием внешних периодических возмущений, в условиях изменения режимов работы. Под внешним периодическим возмущением подразумевалось изменение условий теплоотвода в сторону уменьшения. Величина изменений предварительно расcчитывалась таким образом, чтобы условия работы энергетической установки не выходили за границы зоны безопасной работы реактора. В случае приближения параметров работы к критическим теплоотвод увеличивался до момента возвращения условий работы в прежнее состояние. Изучен амплитудный частотный отклик нелинейно обостренной системы в условиях работы ядерной энергетической установки, нелинейно реагирующей на внешние периодические воздействия. Рассмотрено воздействие внешних циклических возмущений на реактор, исходно находящийся в стационарном рабочем состоянии. Проведены исследования путем численного моделирования конкуренции процессов, протекающих в ядерной энергетической установке, которые определяются временем реакции и временем релаксации системы на периодическое внешнее воздействие. Представлены расчеты зависимости времени релаксации от температуры внешнего воздействия при фиксированной частоте, времени релаксации от частоты внешнего воздействия при фиксированной температуре для систем с разным временем релаксации. Определено, что при расчете зависимости температуры системы от времени внешнего воздействия существует широкая зона возможного частотного регулирования. Для оценки поведения ядерного энергетического реактора в условиях изменения режимов работы создана принципиальная физико-математическая модель состояния реактора, находящегося под внешним гармоническим воздействием, на основе нелинейного уравнения Риккати. Внешнее гармоническое воздействие моделировалось путем изменения условий теплоподвода и теплоотвода вблизи критической точки

The three-dimensional PWR transient code ANTI; rod ejection test calculation

ANTI is a computer program being developed for threedimensional coupled neutronics and thermal-hydraulics description of a PWR core under transient conditions. In this report a test example calculated by the program is described. The test example is a simulation of a control rod ejection from a very small reactor core (to save computing time). In order to show the influence of cross flow between adjacent fuel elements the same calculation was performed both with the cross flow option and with closed hydraulic channels

PWR steam generator chemical cleaning, Phase I. Final report

United Nuclear Industries (UNI) entered into a subcontract with Consolidated Edison Company of New York (Con Ed) on August 8, 1977, for the purpose of developing methods to chemically clean the secondary side tube to tube support crevices of the steam generators of Indian Point Nos. 1 and 2 PWR plants. This document represents the first reporting on activities performed for Phase I of this effort. Specifically, this report contains the results of a literature search performed by UNI for the purpose of determining state-of-the-art chemical solvents and methods for decontaminating nuclear reactor steam generators. The results of the search sought to accomplish two objectives: (1) identify solvents beyond those proposed at present by UNI and Con Ed for the test program, and (2) confirm the appropriateness of solvents and methods of decontamination currently in use by UNI