Device for securing active zone of the nuclear reactor with pressurized water
(57) Abstract:Usage: in devices for fastening equipment installed inside a pressure vessel of a nuclear reactor containing the annular elastic element. The essence of the invention: each of the annular segments of the elastic element is made in the form of helical springs, which fits planted cylindrical rings. 5 Il. The invention relates to a device for fastening internal equipment of a nuclear reactor, namely, devices for securing active zones in the reactor with pressurized water and washed by the cooling fluid.It is known device  to secure the active zone containing the reference cylinder, mounted on the flange on the pressure vessel of a nuclear reactor, the elastic element is disposed between the flanges of the support and the pressure cylinder, biasing the lid of the reactor. The elastic element is made of pipe and contains several ring segments secured to the upper surface of the flange of the support cylinder. The compression of the elastic element is in the sealing of the connector receptacle. This creates a clamping force, which, along with the t of the reference cylinder to the support and keep it from surfacing when exposed to a pressure drop of coolant.A disadvantage of the known device is that during the transition to the loading of the reactor fuel assemblies with a frame made of zirconium alloy instead of fuel assemblies with stainless steel frame is a significant reduction in the force generated by compression springs in the heads of fuel assemblies unit pressure pipes as output when the operating temperature of the heat carrier Zirconia framework of the fuel Assembly is extended to 12-15 mm less than the corresponding channel, formed by the reactor internals are made of stainless steel 08KH18N10T (value movements taken for VVER-1000 reactor with a length of fuel 3.5 m).When the reduction of the pressing force from the spring units of fuel assemblies there is a need to compensate for pressure support and pressure cylinders by increasing the force from the elastic element. Otherwise, the internals will break away from the supports that are given to vibration as their own, and fuel assemblies, and regulators, i.e., significantly reduced the reliability of the reactor.The weakening of the pressure vessel internals to the supports can also occur and exposure.In the limited space allowed in a nuclear reactor for placement of the elastic element, the increase of the pressing force can be achieved, for example, by increasing the wall thickness of the toroidal ring segment. In this case, simultaneously with the increase of linear load decreases the amount of elastic deformation (both relative and absolute), and also decreases the relaxation resistance of such pipes, which necessitates early (before the end of the fuel company) replacement of the elastic element.The aim of the invention is to increase the carrying capacity of the elastic element, retaining the reference cylinder with an active area of ascent, without increasing the dimensions of the elastic element, reducing the vibration of the internal elements of the device and the active zone during the transition to fuel loading with zirconium frame.The device according to the invention is characterized by the fact that each of the annular segments of the elastic element is made in the form of helical springs, which fits planted cylindrical rings.In Fig. 1 shows a diagram of a nuclear reactor, a longitudinal section; Fig.2 section a-a in Fig.1; Fig.3 section b-B in Fig.1; n is ASS="ptx2">The reactor device for securing the support cylinder with the active zone comprises a vessel 1 under pressure, the sealing cover 2. In the vessel 1 is mounted on the flange 3 of the supporting cylinder 4 with an active area containing the fuel assemblies 5. Between the flange 3 of the reference cylinder and the flange 6 of the pressure cylinder communicating with the end cover 2, has elastic element containing the number of ring segments 7, secured to the flange 3. Each of the segments 7 includes a cylindrical helical spring 8, which is mounted with tension cylindrical ring 9. The vessel 1 is equipped with a suction inlet 10 and the outlet pipe 11 and forms with the wall of the support cylinder 4 and lowering the channel 12 of the brine circuit in the reactor.The device operates as follows.The cold fluid enters the pipe 10, having a buried channel 12 through the holes in the bottom of the supporting cylinder, enters the active zone, takes heat from the fuel assemblies 5 and heated, goes through the pipe 11 from the reactor. During the flow of coolant through the reactor pressure decreases and the pressure difference at the inlet and outlet is the force that pushes the supporting cylinder up, if the reference weight kg condition for keeping the supporting cylinder and teplovidelyaushy assemblies from significant movements (causing deterioration and destruction under the influence of the flowing fluid. When sealing the main connector cover 2 through the flange 6 of the pressure cylinder and the elastic segment 7 passes on the flange of the support cylinder, the required contact force, deforming the spring 8 and the ring 9. Since the spring 8 and the ring 9 are made of high strength spring material (for example, of heat-resistant corrosion-resistant alloy HNTR), the elastic element with the same dimensions as the pipe in the prototype (for example, utilized in the industrial production of steel pipe ONT), can withstand much greater linear load than the prototype (2-4 times).Thus, the proposed design of the elastic element makes it possible to increase the contact force of the reference cylinder to the required size without increasing its size, that provides the necessary reliability of the reactor. Device for securing active zone of the nuclear reactor with pressurized water containing the reference cylinder, mounted on the flange on the pressure vessel, the elastic element comprising a number of adjacent ring segments secured to the upper surface of the flange of the support cylinder, cooperating with the flange of the pressure cylinder, biasing the end cap receptacle Pavlichenko springs, which fits planted cylindrical rings.
FIELD: nuclear power engineering.
SUBSTANCE: proposed containment has inner space accommodating condensing chamber, high-pressure chamber, cooling pond, and discharge pipe. It is also provided with condenser communicating with high-pressure chamber. Discharge pipe is component part of inner space that provides communication between high-pressure chamber and condensing chamber. Condenser may be mounted in high-pressure chamber with top end of discharge pipe disposed above condenser. Operating process of condenser in nuclear power plant is characterized in that nondensables are automatically discharged from above-condenser area.
EFFECT: enhanced safety in operating nuclear power plants.
13 cl, 1 dwg
FIELD: nuclear power engineering; nuclear plants for transmutation of radioactive wastes including excess nuclear weapon materials.
SUBSTANCE: proposed method that provides for commencing and ceasing nuclear reaction simply by starting and stopping fuel pumps, effective monitoring and control of nuclear reaction, neutron energy spectrum, and transmutation speed includes production of nuclear-reactor liquid-fuel core by stream of liquid fuel jets formed by means of holes in delivery chamber at core inlet and its discharge to vacant state at core outlet. Core jets are cooled down by means of helium circulating within reactor vessel. Liquid fuel is supplied from liquid state to delivery chamber by means of pumps thereby initiating chain fusion reaction within reactor core. Remaining spaces of liquid fuel loop are always maintained in subcritical state. Stopping liquid fuel pumps causes core disappearance.
EFFECT: facilitated procedure, reduced cost and enhanced safety of radioactive waste transmutation process.
FIELD: nuclear power engineering.
SUBSTANCE: proposed core used for water-moderated water-cooled reactors, and type VVER-1000 in particular, is characterized in that water-uranium ratio of fuel lattice, outer and inner diameters of fuel element cladding are 1.51 to 2.10, 7.00 · 10-3 to 7.50 · 10-3 m, and 5.93 · 10-3 to 6.36 · 10-3 m, respectively, for fuel assemblies incorporating 468 to 510 fuel elements, or water-uranium ratio for fuel lattice, outer and inner diameters of fuel element cladding are 1.49 to 2.06, 7.60 · 10-3 to 8.30 · 10-3 m, and 6.45 · 10-3 to 7.04 · 10-3 m, respectively, for fuel assembly having 390 to 432 fuel elements, or water-uranium ratio of fuel lattice, outer and inner diameters of fuel element cladding are 1.61 to 2.03, 8.30 ·10-3 to 8.89 · 10-3 m, and 7.04 · 10-3 to 7.46 · 10-3 m, respectively, for fuel assembly with 318 to 360 fuel elements, core height to fuel assembly length ratio being 0.7677 to 0.7945.
EFFECT: reduced linear heat loads and fuel element depressurization probability, enlarged reactor power control range, enhanced fuel utilization.
5 cl, 16 dwg
FIELD: research thermal pulse reactors.
SUBSTANCE: proposed nuclear reactor has cylindrical tank of diameter D filled with water moderator and accommodating reactivity modulator incorporating N dry tubes axially and symmetrically disposed over diameter D1 on tank bottom. Dry tubes accommodate movable tubes filled with water, each tube holding two rods made of neutron absorbing material. Rods are rigidly fixed on common hollow shaft at distance R from movable tube axis and at distance 2R from each other. Values of 2R and D1 are found from following expressions: 0.107D > 2R > 0.105D; 0.806D > D1 > 0.8D; protective elements have storage capacitor with spark gaps.
EFFECT: enlarged functional capabilities due to evacuating central test channel in core, reduced neutron background level, enhanced nuclear safety of plant.
2 cl, 5 dwg
FIELD: the invention refers to nuclear technique particularly to construction of homogenous fast reactor on suspension.
SUBSTANCE: the homogeneous fast reactor-reservoir is characterized thereby that thermal contour working on natural circular fine-dispersed dredge of the fuel particles in liquid metal carrier contains an active zone of variable volume, has under critical stagnant zones with an open surface also having a reserve volume. Together with refrigerating part of the liquid metallic refrigerating contour it is contained inside closed volume limited by an external body of the reactor. Liquid lead and its alloys are used as carrier of fuel particles in a fuel contour and thermal carrier in the refrigerating contour and mixture of raw and fissionable species serves as a fuel for starting feeding. The rising section of the fuel contour is fulfilled in the form of a vertical cylindrical housing with inputs from below and outputs from above, lateral openings connecting the housing relatively with assembled and distributed collectors of ramified system of thermal tubes, paved together with the tubes if the refrigerating contour in space between the external wall of the housing and the inner wall of the reactor's body. An ousting plug is immersed in the upper part of the housing with a gap for passing of suspension. The plug is fulfilled with possibility of vertical displacement relatively to the wall of the housing, and the vacant lower part of the housing serves as active zone the volume of which is determined by the position of the plug. The external body of the reactor is fulfilled in the form of high-fusing bucket closed with a protective cover with openings for loading and other technological channels which are designed for keeping non-volatile radioactivity at temperatures no higher than the point of boiling of the lead and located inside the protective structure fulfilled of heat resistant cement-basalt or similar other mineral foundation.
EFFECT: allows to insulate the fuel contour inside closed volume.
4 cl,3 dwg
FIELD: nuclear physics; multiplying neutrons for building subcritical nuclear reactors.
SUBSTANCE: proposed multistage neutron multiplier has a number of multiplication stages abutting against each other. Each stage has coaxially arranged disks of different thickness abutting against each other. Disks are assembled of active material, neutron moderators of two types, and neutron absorber. They are alternating in stage so as to ensure unidirectional movement of neutrons and their multiplication.
EFFECT: enhanced neutron multiplication factor.
2 cl, 2 dwg
FIELD: radiation engineering.
SUBSTANCE: proposed gamma-ray installation used in particular to irradiate modular objects to sterilize, pasteurize, or modify them has irradiation chamber accommodating isotope radiation sources placed in irradiator, system for displacing irradiator and object being irradiated made in the form of pushing conveyer, control and radiation protective system. Isotope sources are placed in irradiation chamber into two parallel flat irradiators mounted for free sequential passage of target object modules on all sides of irradiator so as to ensure their two-way irradiation.
EFFECT: enhanced radiation safety and irradiation efficiency.
FIELD: fuel cells designed for use in gas-cooled nuclear reactor core.
SUBSTANCE: fuel cell 10 designed for use in gas-cooled nuclear reactor has assembly of two adjacent fuel plates 12a, 12b disposed relative to one another and shaped so that they form channels 14 for gaseous coolant flow. Fuel plates 12a, 12b incorporate elementary fissionable particles, better non-coated ones, implanted in metal matrix. Metal coating may be deposited on both ends of each plate 12a and 12b.
EFFECT: enlarged heat-transfer surface, enhanced power density per volume unit.
13 cl, 5 dwg, 1 tbl
FIELD: nuclear technology; atomic power stations with water-cooled nuclear reactors.
SUBSTANCE: the invention is pertaining to the field of nuclear technology, in particular, to atomic power stations with water-cooled nuclear reactors. The nuclear reactor contains: the body and the cover with the branch-pipes for outputs of the detectors of the intrareactor control; the pins with the screw nuts for tightening of the above-mentioned cover to the body. On the branch-pipes for outputs of the detectors of the intrareactor control there are safety devices fixed on the pins for tightening of the cover to the body by additional screw nuts. The invention allows to increase safety of the nuclear reactor operation.
EFFECT: the invention allows to increase safety of the nuclear reactor operation.
FIELD: nuclear industry and other industries using parts suffering in operation impact of liquid-metal temperature and corrosion.
SUBSTANCE: in manufacturing fuel element with heat-transfer liquid-metal layer use is made of not pure lead but its alloy incorporating chemical elements of fuel element cladding in amount affording chemical equilibrium of fuel element cladding with contacting heat-transfer lead layer under temperature and other operating conditions. Using low-alloyed lead instead of high-cost pure lead enhances corrosion resistance of fuel element cladding.
EFFECT: enhanced service life and reduced production cost of fuel elements.
FIELD: pressurized-water reactor equipment.
SUBSTANCE: proposed device for securing pressurized-water reactor core with coolant flowing over it has supporting cylinder and flexible member. Supporting cylinder is mounted on pressurized tank flange. Flexible member has a number of adjacent circular segments disposed between and engageable with supporting cylinder flange and pressurized tank cover flange. Each circular segment of flexible member has segmental supporting plate. The latter mounts hold-down devices secured thereon by means of locking devices. Each hold-down device has supporting sleeve accommodating working element of precompressed thermally expanded graphite which is locked therein by means of locking device, as well as hold-down bushing. The latter is in contact with working element or with locking device.
EFFECT: reduced vibration of reactor core when changed over to fuel load incorporating zirconium-can fuel assemblies.
7 cl, 10 dwg