Protective container for transportation of spent nuclear fuel
(57) Abstract:Protective container includes a housing that is inserted into the cavity of the removable housing part, in which holes in the top Board and the diaphragms placed pipe covers. The protective container is closed from above by a sealing cap. Removable part is equipped with attached tube channel, intended for removal of radioactive water from the bottom of the container by way of vacuum suction. The axis of the channel is offset from the axis of the container at a distance of 0.75-0.95 radius of the inner cavity of the container, and the lower end of the tubular channel is located above the bottom of the container with a clearance of not more than the inner radius of the pipe channel. The lower flange of the container is equipped with an additional removable flange having a slope in the direction of the tube channel on the angle 1-4ofor the round-up of radioactive water into the corner of the bottom of the container when it is removed by way of vacuum suction through the pipe channel with the cover off. The technical result of the present invention is expressed in nuclear safety. 4 Il., table 1. The invention relates to a mobile protective containers for safe transportation of spent nuclear fuel from storage after jadernoi reaction.One of such conditions is the lack of water in the container or its presence below the permissible according to the calculations of nuclear security number. To do this, after boot covers with spent fuel in the container and before transporting water from the bottom of the container should be removed to values below the allowable amount. For example, for protective container TK-18 the presence of water after boot covers SNF before transportation should not exceed 2.5 litres.Known protective container, taken as a prototype (see "Containers for transportation of spent fuel elements of nuclear power plants", Proceedings of CKTI, 142 issue, Leningrad, 1977, page 13, Fig. 2), comprising a housing that is inserted into the cavity of the container is removable part, in the holes of the top Board and transverse diaphragms where pipe covers SNF, and closed at the top by a sealing cover.Also known containers (see ed. St. N 1301205, Fig. 3, Fig. 4 and Fig. 5), in which the removal of water from their cavity to drain the bottom by gravity through the openings in the walls of the containers and through the shutoff valves located below the bottom of the container.The disadvantages of these protective containers are available if asiausa sealing system the discharge of radioactive water from the bottom of the container in a team capacity without leaking it on the floor of the room. This full tightness of the drain system is not achieved and the current leakage of radioactive water polluted areas, which will remove the water from the containers.Known pumping plant for the removal of liquids by their vacuum suction from the bottom of the tank through the top of their neck. (see "Sanitary-technical equipment of buildings", C. S. Kedrov, E. N. Fisher, M.: stroiizdat, 1989, page 302, Fig. 20.1 (b). The specified pump installation does not require holes in the walls of the container. The pump unit consists of a tank (inlet tank, pump and suction pipe. When possible leakage of fluid in the joint of the vacuum system to the pump at the top of the neck tank (inlet tank) are not on the floor of the room, and down again to the bottom of the tank (inlet tank), which eliminates possible contamination of the premises by the liquid.The objective of the invention is to simplify the design of the container for removing radioactive water from the bottom of the container without holes and valves in the walls and no water leaks on floor space, as well as the reduction of the balance of the water at the bottom of the container due to the tilt of its axis for eviction of water in the corner with the deletion.This dosha offset from the axis of the container at a distance of 0.75-0.95 radius of the inner cavity of the container, the upper end of the tubular channel is inserted in the top Board removable parts in sostykovochka socket attach the vacuum system for collecting water from the bottom of the container through the tubular channel and the bottom channel is located above the bottom of the container with a gap equal to not more than the inner radius of the pipe channel, while the lower flange of the container is equipped with an additional removable flange having a slope in the direction of the pipe channel at an angle of 1 to 4o.Eccentric attachment tube channel for the removable parts with its location in the cross section of the cavity of the container eliminates the possibility of water leaks on the floor of the premises and provides the suction of water from the corner of the container, and allows the body of the container without holes and isolation valves in the walls, which simplifies the design of the container. The connecting socket in the top Board removable parts, in which is inserted the upper end of the tubular channel provides the ability to attach to a vacuum system for collecting water from the bottom of the container through the tubular channel.The gap end of the tube channel on the bottom of the container size is not more than the inner radius of the channel allows the use of the phenomenon of wetting by water butt canal and capillary affma, after its suction reduces the depth of the residual water in the zone of the tube channel below the gap.Equipping the lower flange of the container attached to it additional removable flange with a gradient of 1-4oprovides the optimal inclination of the container in the direction of the pipe channel and the sleeves of water in the corner area of the bottom of the container before it is vacuum suction that reduces the amount of residual water in the container after its suction.The invention is illustrated by drawings, where Fig. 1 shows the proposed protective container, a vertical section; Fig. 2 shows a node I Fig. 1 - position of the pipe channel in the removable parts and the cavity of the container, as well as placement driven into a corner area of the water container by tilting the container in the direction of the pipe channel, vertical section; Fig. 3 shows a cross section a-a in Fig. 2 - positioning the tubular channel and the water at the bottom of the container; Fig. 4 is a wiring diagram for the connection of the vacuum system in the expansion slot of the tube channel when the cover of the container, a vertical incision.Protective container includes a housing 1, a cover 2, the removable part 3, pipe covers 8 installed in the removable part 3 their bottom ends to the bottom of the housing 1; and t is the removable parts 3 installed replaceable sleeve 6 to provide the same clearance under the cover 2 for all of the covers 7 and 8. Removable part 3 is supplied attached to the top Board and the spacer apertures 12 pipe channel 5 for collecting the water from the bottom of the housing 1.The axis of the pipe channel 5 offset eccentric (Fig. 3 and Fig. 2) relative to the axis of the container at a distance (0,75 - 0,95) the radius of the inner cavity of the container. The bottom end of the pipe channel 5 is located above the bottom of the container with a gap equal to not more than the inner radius of the pipe channel 5, and above the upper end of the tubular channel 5, inserted in the top Board removable parts 3, there is a connecting socket 4 (see Fig. 1) for connecting the sealing device 14 (Fig. 4) above the cavity of the housing 1 through a flexible hose 15 to a vacuum system for collecting water from the bottom of the container when the cover 2. For tilting the axis of the protective container and eviction of water in the corner area of the bottom of the lower flange 9 of the container is fitted (Fig. 1) attached to it by means of bolts 10 and nuts 11 additional removable flange 13 having a slope of 1 to 4oin the direction of the pipe channel 5.The optimum angle of inclination of the container 1 to 4oin the direction of the pipe channel, providing a minimum residual volume of water in the bottom of the container when the eccentric offset of the axis of the channel, confirmed the following BR> C is the eccentricity of the tubular channel, in the present invention it is set to C = (0,75 - 0,95) R;
d is the distance to the axis of the channel from the inner cylindrical cavity of the container d = R - C = (0,05 - 0,25) R;
r is the inner radius of the tubular channel;
W - the gap between the bottom of the container and the bottom end of the pipe channel in the present invention taken W < r;
- the angle of the container in the direction of the pipe channel;
h - the height of the water "hoof" when the tilt angle ;
x - base height of the water "hoof" when the tilt angle ;
m - length water "hoof" to pipe channel when the tilt angle ; m = x - d;
a - half the length of the straight side of the water "hoof" when the tilt angle .Calculation of residual water at the bottom is inclined in the direction of the channel of the container (Fig. 2 and Fig. 3) is produced by the known formula for the volume of water "hooves" (see I. N. Bronstein, K. A. semendjajew - "Handbook of mathematics", Moscow, "Nauka", 1986, page 188, Fig. 2.51)
< / BR>where
< / BR>< / BR>where
From (2) and (3) follows:
< / BR>Volume according to the formula (4) when changing x has a minimum, which can be found by calculating the value of which requires complex calculations.In a first approximation, the value of x when totoromobile minimum square secene, which will match VminOSTwhere, substituting (3), we get
< / BR>where xSmin= 2d, ... (6) and Smin = 2W d (7).We get the following, substituting (6) into (4):
< / BR>thus where
As an example, we determine the values of VminOSTand*in the container TK-18, with values of R = 38,8 cm; d = 4.8 cm; W = 0.1 cm, 0.2 cm; 0.3 cm; 0.4 cm; 0.5 cm;
< / BR>< / BR>The results of calculations are presented in table I.When the vertical position of the container, i.e. when = 0oand W = 0.3 cm volume of water at the bottom of the container is 1418,1 cm3. When tilting the container by 3.58oand W = 0.3 cm, the amount of water the container is reduced in time.An example with W = 0.3 cm is given from the practice of sucking water from the bottom of the container TK-18. When the suction wetting water end of the channel and the capillary effect in the channel r = 0.5-0.6 cm when W < r using vacuum pressure not exceeding 30000 PA (225 mm RT.CT.) allows you to remove the water from the container TK-18 to a residual depth in the area of the pipe channel W 0,3 see the Depth of the residual water was controlled drop to the bottom through the pipe channel pin on the size of the wetted by water footprint at the end of the pin, the lower end of which is pre-covered with chalk or kaolin.In the remainder of the water at the bottom of the container, taken 1 to 4o. Large draft angles are unacceptable because of the possibility of jamming of the diaphragm covers when installing them under the pressure of its own weight in aperture removable parts of the container.To remove the water from the bottom of the protective container (Fig. 1) it is installed on the horizontal floor of the room, on the bottom attached additional flange 13 having a draft angle of 1 to 4othat provides tilting of the container and the sleeves of the water at its bottom in the area of the pipe channel 5. Protective container can also be installed in the shop decompression the pit, room for boats, etc.The removal of water is produced when the cover 2 after loading into the cavity of the container covers 7 and 8. For this purpose the connecting socket 4 installing the sealing device 14 (Fig. 4) and the pressure wheel is compressed on its end in the connecting socket 4 sealing rubber strip, and the upper hose 15 is connected to the vacuum system.After that include vacuum and produce a suction of water from the bottom of the container through the channel 5, the connecting device 14, the hose 15 into the drain tank vacuum system.It is possible water leak in the sealing connecting socket 4 through the gaps in removable the e removal of water from the container. About the end of the suction from the bottom of the container indicates a leak in the gap end of the pipe channel 5 over the bottom of the housing 1, the increase of the vacuum pressure and the characteristic audible noise. Then turn off the vacuum system, disconnect the hose 15 and remove the sealing device 14. The depth of the residual water in the zone of the pipe channel 5 control drop to the bottom through the channel 5 pin on the size of the wetted by water footprint at the end of the pin, pre-coated with chalk. After that, the body 1 of the container, install the cover 2.The proposed protective container and ensures reliable operation in accordance with the nuclear safety requirements by simplifying construction, reducing the remaining water in the container to lower the amount of permissible and excludes the contaminated water of the building during its removal from the container. Protective container for transportation of spent nuclear fuel, comprising a housing inserted into the body cavity of the removable part, in the holes of the top Board and diaphragms where pipe covers SNF, and closed at the top by a sealing cap, wherein the removable portion is supplied attached to nutrena cavity of the container, the upper end of the tubular channel is inserted in the top Board of the removable parts in the connecting socket attach the vacuum system for collecting water from the bottom of the container through the tubular channel, and the lower end of the tubular channel is located above the bottom of the container with a clearance of not more than the inner radius of the pipe channel, while the lower flange of the container is equipped with an additional removable flange having a slope in the direction of the pipe channel at an angle of 1 to 4o.
FIELD: safety facilities for handling radioactive materials.
SUBSTANCE: proposed internal container designed for long-time storage and transport of high-radioactivity materials such as plutonium dioxide has container body closed with sealed cover and specified-volume charging box placed in this body and provided with its respective cover. Container body has cylindrical passage for charging box that mounts additional internal cover provided with gas filtering device and hermetically installed relative to its surface for axial displacement. External cover of container body is provided with shut-off valve accommodating gas filtering device installed therein between inner space of container and valve seat. Such mechanical design of container enables reducing irreparable loss of plutonium during its long-time storage and transport.
EFFECT: enhanced safety and reliability , enlarged functional capabilities of container.
7 cl, 2 dwg
FIELD: handling radioactive wastes.
SUBSTANCE: proposed method for nuclear fuel storage in container includes introduction of nuclear fuel in fuel collector, as well as preparation of formwork to receive concrete body and installation of fuel collector into formwork. Formwork is immersed in tank and concrete is placed in immersed formwork to form concrete housing. Formwork with concrete housing formed therein is extracted from tank. System for manufacturing nuclear fuel storage container and for holding fuel in fuel collector installed in concrete housing that forms part of storage container has water tank. In addition it has tools for assembling formwork for storage container concrete housing and facilities for conveying formwork and fuel collector to water tank. It also has facilities for introducing nuclear fuel in fuel collector, facilities for concrete placement in formwork, and those for removing formwork from water tank. Nuclear fuel storage method includes piling of containers so that their central channels are aligned and held open for intercommunication. Fluid cooling agent is supplied to bottom end of central channel in lowermost storage container and discharged from top end of central channel in uppermost storage container.
EFFECT: enhanced reliability of radioactive waste isolation.
25 cl, 7 dwg
FIELD: storage of hazardous materials.
SUBSTANCE: proposed device for keeping in storage hazardous materials such as spent radioactive nuclear fuel has cylindrical concrete housing accommodating three-dimensional pre-stressed hardware and axially elongated hazardous-material storage area. Pre-stressed hardware includes hardware fittings spirally passed about storage area and disposed in concrete housing close to outer surface.
EFFECT: enhanced reliability of hazardous material storage.
7 cl, 8 dwg
FIELD: shipment and storage of highly active wastes.
SUBSTANCE: proposed container for transport and dry storage of spent nuclear fuel has hermetically sealed storage tank and can holding spent nuclear fuel. In addition, it has external steel-reinforced concrete casing with outer and inner metal shells and bottom, cooling ducts, and fixing dampers. Hermetically sealed tank is provided with transport ring that holds shell in position relative to longitudinal axis of casing and with three detachable lids. It is also provided with dampers disposed over entire perimeter of inner cylindrical shell that function to lock cylindrical shell on lid and outer steel-reinforced concrete casing and to transfer heat therefrom. Cooling system is designed so that cooling air flows through cylindrical gap between outer surface of tank and inner surface of external steel-reinforced concrete casing over cooling ducts.
EFFECT: enhanced operating reliability of container.
5 cl, 4 dwg
FIELD: handling spent nuclear fuel.
SUBSTANCE: proposed module designed for storage of spent nuclear fuel has tight case with inner space to receive spent nuclear fuel. Module is provided with ring made of solid ferromagnetic material possessing magnetocaloric properties. Ring is provided with drive and is free to rotate about its axis. It is disposed so that part of this ring is inside module in immediate proximity of tight tank holding spent nuclear fuel. Other part of ring is placed in constant magnetic field outside of module and can be cooled.
EFFECT: enhanced safety of spent nuclear fuel dry storage.
1 cl, 2 dwg
FIELD: nuclear engineering.
SUBSTANCE: proposed device for storage and/or transport of spent nuclear fuel has housing and cover forming inner space for holding spent nuclear fuel. Inner space is divided by means of partitions into compartments, each compartment being meant to receive spent fuel assembly. Each compartment accommodates two tanks holding metal hydride or intermetallic compound. These tanks are provided with channels pressurized with respect to inner space of device which are used to discharge hydrogen produced due to heat released by fuel assembly. Hydrogen outlet channels are designed for charging metal hydride through them and are provided with closing valves.
EFFECT: enhanced reliability of spent nuclear fuel storage and its safety in transit.
1 cl, 3 dwg
FIELD: transport and storage of spent nuclear fuel.
SUBSTANCE: proposed method includes placement of fuel assemblies in transport package incorporating container and split damping casing designed so as to minimize lift of container when inserting it in split damping casing. Transport package is conveyed to storage place where container is freed of casing, whereupon spent fuel assemblies are kept in storage place. In the process spent fuel assemblies are first placed in container and then the latter is inserted in vertical position into split damping casing made in the form of removable drum with butt-end covering and base that functions as end lid of this drum. Charged container is installed on base, covered on top with removable drum, and the latter is fastened to base. Then split damping casing is secured to container, whereupon transport package is conveyed in transport position to storage place.
EFFECT: enhanced reliability of storage and transportation.
6 cl, 5 dwg
FIELD: nuclear engineering.
SUBSTANCE: proposed method includes loading spent fuel assemblies in metal-concrete container, conveying the latter to intermediate storage site, and holding it on storage sire. Shipping unit for conveying spent fuel assemblies to intermediate storage site has flat-car for carrying vertically mounted container holding spent fuel assemblies. Container is provided with external removable circular supporting member engageable with mating supporting surface of flat-car frame and means for locking container relative to mentioned frame. Shipping unit is provided with jacks for lifting the frame to load spent fuel assemblies in container. Side surface of container body has rigging members in the form of seats on its top and bottom ends. Bottom end of container is installed inside mentioned circular supporting member. Container locking means include radially disposed submersible adjustable stops.
EFFECT: enhanced reliability and safety of proposed method and device.
4 cl, 8 dwg
FIELD: storage and transportation of used nuclear fuel.
SUBSTANCE: metal-concrete container for transportation and/or storage of used assemblies of fuel elements of nuclear reactors has case with bottom, internal protection air-tight cap, edge damping members. Casing with central cell is inserted inside cavity of case. Peripheral cells are disposed around central cell for mounting housings with used assemblies of fuel elements. Peripheral cells are made in form of tubular members that are mounted to have spaces in relation to internal protection air-tight case and bottom of case. Casing has longitudinal rod members disposed around circle in relation to central cell of casing. Container has first and second sheet members which are mounted along height of case and are connected for disconnection by means of longitudinal rods. Edge damping members are made in form spring-shaped members and they are mounted onto internal protection air-tight cap each in opposite to corresponding cell of casing for interaction with housing under normal conditions of exploitation of metal-concrete container.
EFFECT: higher safety of handling of loaded container.
6 cl, 7 dwg
FIELD: storage and transportation of spent nuclear fuel.
SUBSTANCE: proposed metal-concrete container for transportation and/or storage of nuclear-reactor spent fuel assemblies has housing with bottom, internal pressurizing safety cover, hood inserted into housing and provided with cells to receive boxes with spent fuel assemblies. Container also has damping members engageable with cover on inner surface end, with housing bottom, and with housing internal wall. Hood is installed within housing in a space relation to housing internal wall. Side damping members are installed between the latter and hood. Each damping member is made in the form of longitudinal rod passed through holes in respective first and second sheet members installed throughout container height on internal wall of housing and on hood and disposed in parallel with housing bottom.
EFFECT: enhanced reliability of spent nuclear fuel storage.
6 cl, 5 dwg