Abstract:
All possible loading patterns for a nuclear reactor core are searched and optimized for compliance with design constraints. The fuel inventory is divided into a few batches according to coarse levels of reactivity. A recursive enumeration process identifies patterns meeting selected core position constraints, which can be user modified to adjust the search space size. For the batch loading patterns satisfying the constraints, the batches are divided into several smaller batches. A sensitivity matrix linearizing the relationship between fuel assembly position and the depletion model is processed through mixed integer linear programming with branching and bounding to identify an optimal daughter loading pattern. The process is repeated through several levels of batch refinement and selection of optimal daughter patterns, including a level where burnable absorbers are assigned to feed assemblies, until the individual fuel assembly level is reached. The multiple optimal patterns remaining provide a range of solutions.
Abstract:
The present invention is to provide a reactor core that allows a nuclear plant to continuously operate for a long term period, for example 15 years or longer, without requiring any fuel exchange, reduces the duration and number of maintenance steps involved in regular plant inspections, markedly improves plant availability and economic efficiency, and is effective in terms of nuclear nonproliferation.A plurality of fuel assemblies 103, themselves obtained by arranging fuel rods 100 and water rods 107 in square lattices, are arranged in a square lattice at a certain pitch. The blades 102a of a cross-shaped (cruciform) control rod 102 in a cross section are inserted into four adjacent spaces formed by four fuel assemblies 100 facing each other. A value of 0.06 cm−1 or greater is selected for the ratio (B/S) of the width (B) of each blade on the cruciform control rod 102 and the surface (S) of the fuel lattice defined by the surface area of a square whose side is equal to the pitch between the fuel assemblies 103.
Abstract:
A cask includes a trunk body that includes a basket having a square pipe or a plate member forming a cell that contains a spent fuel assembly, and a neutron shield that is formed by filling a composition for neutron shielding between the trunk body and an outer cover surrounding the trunk body. The composition includes a refractory material, a density increasing agent, and a neutron shielding material composed mainly of a polymer.
Abstract:
The invention relates to an inspection probe for an internal wall of a duct, comprising at least one sensor mounted in a support adapted to be moved inside the duct while pressing said sensor flat against said internal wall. The support is formed by a shell which is molded onto the sensor and comprises a body provided with a window for positioning said sensor and means for attaching said sensor flat against the internal wall of the duct, said means being integrally molded with the body.The invention has applications in the non-destructive testing of ducts in nuclear power plants.
Abstract:
An improved method of increasing the power output of an existing nuclear power plant includes increasing the thermal power output of the plant's nuclear island and constructing of an auxiliary BOP to handle the increased thermal power. The thermal power of the nuclear island can be increased such as by increasing the thermal power of the plant's reactor, by replacing the plant's steam generator with one that is more efficient, and by increasing the flow rate and/or change in temperature of a coolant in a secondary cooling loop of the plant. The thermal power of the reactor can be increased such as by replacing existing cylindrical fuel rods with fuel rods having a relatively greater surface area to volume ratio and/or by increasing the flow rate and/or the change in temperature of a coolant of a primary cooling loop. The auxiliary BOP can be constructed while the plant is in operation, and can then be connected with the nuclear island during a maintenance operation on the reactor.
Abstract:
There are disclosed an inspection system for and a method of confirming the soundness of a transported object while the object is being transported and handled. Waveform sampling sensors are mounted on the transported object and a transportation container, and a GPS and a CCD camera are mounted on a transportation vehicle. Sampled data are sent via the Internet Web in real-time to a remote transported object monitoring office at all times while the object is being transported based on bidirectional communications between the transportation vehicle and the remote transported object monitoring office. Various items of information including generated accelerations, times at which the accelerations are generated, raw waveforms of the accelerations are successively displayed on a traveling route on a map displayed on a personal computer for bidirectional confirmation of the soundness of the transported object in real-time.
Abstract:
The invention concerns a neutron shielding material for maintaining sub-criticality based on unsaturated polymer: Said material comprises an unsaturated polyester resin, at least an inorganic boron compound, and at least a hydrogenated inorganic compound, in amounts such that the boron concentration is 4.1021 to 25.1021 atoms per cm3 and the hydrogen concentration is 3.1022 to 5.5.1022 atoms per cm3.
Abstract translation:本发明涉及一种用于维持基于不饱和聚合物的亚临界性的中子屏蔽材料。所述材料包括不饱和聚酯树脂,至少一种无机硼化合物和至少一种氢化无机化合物,其量使得硼的浓度为4.10 21>至25.10 21个原子/ cm 3,氢浓度为3.10 22.5至5.5.10 22原子/ cm 3。
Abstract:
An electromagnetic field deflecting garment made up of a dry knitted conductive fabric (2) with conductive filaments (3) disposed in parallel fashion, edged with a lattice conductive fabric (4) with filaments (5) disposed in a criss-crossed pattern, an electrical circuit (10) able to disperse the electromagnetic signal coming from the garment being connected to said fabric (4).
Abstract:
A radiation shield is provided for use on patients undergoing radiotherapy treatment. The shield is made of a suitable radiation absorbing material for preventing the transmission of high energy radiation to the patient's non-treatment areas. The device may further comprise an exterior surface layer for absorbing low energy photons. The shield is sized and shaped to conform to a patient's anatomy and to provide the necessary amount of absorbing material closest to the beam edge while not interfering with the beam. The shield may further comprise an optional cavity located on the interior surface of the shield which may be lined with a soft compressible material for conforming to a patient's unique anatomy. The shield may be further provided with dosimeters mounted on the exterior surface of the leading edge as well as on the interior surface of the shield. The dosimeters may be connected in a systematic manner with the linear accelerator such that the machine could be automatically switched off or warnings given if the patient is receiving too much radiation scatter dose.
Abstract:
In order, in a pressure accumulator, to generate a required operating pressure of a fluid situated in the pressure accumulator, a heater device is provided, disposed in an upper region of the pressure accumulator. The device generates a vapor cushion and the required operating pressure. Where necessary, when the fluid flows out, the pressure in the pressure accumulator is automatically reduced after the level has fallen below a defined filling level, as a result of the vapor condensing at a cold insulating device with a high heat-accumulation capacity. The pressure accumulator is preferably used as an emergency shut-down tank or as an emergency accumulator in a nuclear power plant.