JPH0136600B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating and drying method for a radioactive waste treatment device, and in particular, to a method for heating and drying a radioactive waste treatment device, and in particular, a method for drying and evaporating radioactive waste liquid or slurry generated at a nuclear power plant, etc., and solidifying it. The present invention relates to a method for heating and drying a radioactive waste processing device suitable for heating the waste processing device and drying it after cleaning.

An example of a heating and drying method for a conventional radioactive waste processing apparatus will be explained with reference to FIG.

FIG. 1 is a system diagram of a radioactive waste processing apparatus that implements a conventional heating and drying method for a radioactive waste processing apparatus, in which a conduit 50 provided with a liquid supply pump 10 and a liquid supply valve 30 is connected, A heating jacket 11 connected with conduits 51 and 52 for heat medium supply and discharge.
A drying device 14 is provided with a rotary blade 13 driven by a drive device 12 such as an electric motor so as to be rotatable therein, and a drying material hopper 15 and a drying material Hopper 15 and dry matter valve 3
A feeder 18 is connected at one end through a screw 1 and has a screw 17 therein driven by a screw drive device 16, and a drain tank is connected to one end of the feeder 18 by a conduit 54 provided with a drain valve 32. 19, and a solidifying material mixing device 20 connected to the other end of the feeder 18 via a conduit 55 via a feeder outlet valve 33, and a conduit 56 provided with a solidified material gate valve 34. A processing device 21 is connected, and a condensate outlet valve 3
5 for the supply of cooling water and a conduit 57 provided with
An evaporator comprising a condenser 22 connected to discharge conduits 58 and 59, respectively, and a suction device 23 provided between vent outlet valves 36 and 37 of a conduit 60 connected to the condenser 22. A material processing device 24 is connected by a conduit 61. In addition, the solidifying material mixing device 2
0, the dehumidifier 25 is connected by a conduit 62 provided with a valve 38.

Radioactive waste such as radioactive liquid waste or slurry generated at a nuclear power plant or the like is supplied at a predetermined supply capacity from a liquid supply pump 10 to a drying device 14 via a liquid supply valve 30 and a conduit 50. Here, the radioactive waste is transported by rotary blades 13 that are driven and rotated by a drive device 12.
Due to the centrifugal force of
The heat medium flowing through the conduit 52 is heated to evaporate and dry. The evaporated material is supplied via conduit 61 to condenser 22, where it is supplied via conduit 58, and is also supplied via conduit 58.
The condensed liquid is condensed with the cooling water discharged from the condensate outlet valve 35 and is sent to another water treatment device (not shown) through the conduit 57. Further, the non-condensable gas in the evaporated matter is sucked by the suction device 23 via the vent outlet valve 36, and is sent to another vent processing device (not shown) through the conduit 60 via the vent outlet valve 37. On the other hand, the dried material is supplied to one end of the feeder 18 via the dried material outlet pipe 53 and the dried material valve 31, and is transferred to the other end of the feeder 18 by the screw 17 driven by the screw drive device 16. The dried material transferred to the other end of the feeder 18 is
It is supplied to the solidification material mixing device 20 through a conduit 55 through the feeder outlet valve 33, where it is mixed with a solidification material such as asphalt or plastic, and then to the solidification processing drum 70 through the solidification gate valve 34 and a conduit 56. Supplied and filled. Note that the drain collected at one end of the feeder 18 is drained from the drain valve 32.
The liquid is discharged through the conduit 54 to the drain tank 19 and stored therein.

In order to carry out this series of processing smoothly, the radioactive waste processing equipment must be maintained in good health. In other words, radioactive waste is usually removed by evaporation.
Because the residual moisture content is dried to a few percent by weight or less,
The dried material distribution route (hereinafter abbreviated as dried material distribution route) from the drying device 14 to the solidification processing device 21 is as follows:
If the condition is not completely dry before operation, dry matter will adhere to areas where moisture remains, leading to the growth of solids and hindering smooth operation. In addition, if the distribution path of the dried material is lower than the temperature of the dried material, that is, close to room temperature, a small amount of residual moisture in the dried material or evaporated matter discharged together with the dried material may flow through the dried material. It condenses and adheres to the route, causing solid matter to adhere and grow, interfering with smooth operation. Therefore, in order to solve these problems and operate the radioactive waste processing equipment smoothly, the radioactive waste processing equipment has conventionally been heated and dried by the following method.

First, to heat the radioactive waste processing equipment before processing radioactive waste, an electric heater or heating jacket is installed in each dry material distribution path, and the dry material distribution path is controlled by the electric heater or heating jacket to maintain the temperature of the dry material. For example, drying of the radioactive waste processing equipment after cleaning is performed by directing dry air dehumidified by the dehumidifier 25 through the valve 38 and through the conduit 62 to the solidification processing equipment 21. This is done by supplying the dried material to the dry material and circulating the dried material in the opposite direction.

This heating and drying method for radioactive waste processing equipment has the following drawbacks.

(1) Some parts, such as the drive mechanism, may not be heated sufficiently locally, so it takes a long time to heat them, or
Alternatively, heating tends to be insufficient.

(2) After cleaning, it is difficult to completely dry the drain in the retention area with dry air, and therefore it takes a long time to completely dry it.

The present invention is aimed at eliminating the above-mentioned drawbacks, and is capable of heating and drying a radioactive waste processing equipment after supplying gas to the drying equipment and heating the gas with a heating medium flowing through a heating jacket. By supplying and circulating the heated gas from the drying device to the solidification processing device via the drying material outlet pipe, the distribution path of the dried material can be sufficiently heated and dried in a short time. The present invention provides a heating and drying method for radioactive waste processing equipment that allows for the heating and drying of radioactive waste processing equipment.

An embodiment of the present invention will be explained with reference to FIG.

FIG. 2 is a system diagram of a radioactive waste treatment apparatus embodying the present invention. In FIG. 2, the same devices and parts as in FIG. 1 are designated by the same symbols and their explanations will be omitted.

In FIG. 2, a conduit 63 provided with a valve 39 and open to the atmosphere at one end connects the vent outlet valve 36 and the suction device 2.
A conduit 64 is connected to the conduit 61 between the suction device 23 and the vent outlet valve 37, and is branched from the conduit 60 between the suction device 23 and the vent outlet valve 37 and provided with a valve 40. Further, the solidification material mixing device 20 of the solidification processing device 21 is provided with valves 41 and 42, and a conduit 65 with one end open to the atmosphere is connected to the valves 41 and 42.
A conduit 65 branched from the conduit 65 in between and provided with a valve 43 is connected to the conduit 60 on the upstream side of the suction device 23 . The heating and drying of such a radioactive waste treatment device is performed as follows.

Liquid supply valve 30, drain valve 32, solidified material gate valve 3
4, condensate outlet valve 35, vent outlet valve 36, 3
7. After closing the valve 42 and opening the dry matter valve 31, feeder outlet valve 33, and valves 39 to 41, 43,
The suction device 23 is driven. Gas, for example air, is thereby drawn into the suction device 23 via the valve 39 via the conduits 63, 60, and then via the conduit 60, via the valve 40, via the conduits 64, 61 and into the drying device 14.
is supplied to The air supplied to the drying device 14 is heated by the heating medium flowing through the conduit 51, the heating jacket 11, and the conduit 52, and then the heated air is passed from the drying device 14 through the dried material outlet pipe 53. , is supplied to the dry material hopper 15 of the solidification processing device 21, and the solidification processing device 21 is connected to the dry material hopper 15.
5, dry matter valve 31, feeder outlet valve 33, conduit 5
5. The solidifying material mixer 20 and the solidified material mixer 20 are sequentially connected to each other, and the solidified material is discharged from the conduit 65 via the valve 41. During this time, the distribution route of the dried material is sufficiently heated by the heated air.
dried. Note that the air discharged from the solidification processing device 21 may be returned to the upstream side of the suction device 23 via the valve 43 and the conduit 66, and may be resupplied to the drying device 14 by the suction device 23. It is also possible to open the valve 43 and release it to the atmosphere via the valve 42 and the conduit 65.

In the method of heating and drying a radioactive waste processing equipment as in this example, heated air is circulated through the distribution path of the dried material, so that the distribution path of the dried material is sufficiently heated and dried. , can be done in a short time, and
It is not necessary to provide an electric heater or a heating jacket in the distribution path of the dried material, and a dehumidifying device is also not required, so that the cost of the device can be reduced and the structure of the device can be simplified. Furthermore, since the device structure can be simplified, it is possible to prevent radioactive substances from leaking out of the device.

Note that if the rotary blade is rotated when heating the air in the drying device, the film heat transfer coefficient inside the drying device will be improved, and the air can be heated even more efficiently.

As explained above, the present invention performs heating and drying of a radioactive waste processing equipment by supplying gas to the drying equipment, heating the gas by a heating medium flowing through a heating jacket, and then heating and drying the radioactive waste processing equipment. By supplying the dried gas from the drying device to the solidification processing device through the drying material outlet pipe and distributing it, the distribution path of the dried material can be sufficiently cleared.
It also has the effect of heating and drying in a short time.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a radioactive waste processing apparatus that implements the heating and drying method of a conventional radioactive waste processing apparatus, and Fig. 2 is a diagram illustrating an embodiment of the present invention. It is a system diagram of the implemented radioactive waste treatment equipment. 11... Heating jacket, 12... Drive device,
13... Rotating blade, 14... Drying device, 15... Dry material hopper, 16... Screw drive device, 17
... Screw, 18 ... Feeder, 20 ... Solidification material mixing device, 21 ... Solidification processing device, 23 ...
Suction device, 24... Evaporated matter processing device, 30... Liquid supply valve, 31... Dry matter valve, 32... Drain valve, 3
3... feeder outlet valve, 34... solidified material gate valve,
35... Condensate outlet valve, 36, 37... Vent outlet valve, 39 to 43... Valve, 51, 52, 55,
60, 61, 63 to 66... conduit, 53... dry matter outlet pipe.

Claims (1)

[Scope of Claims] 1. A drying device for drying radioactive waste in which a rotary blade is rotatably installed and a heating jacket through which a heat medium flows is enclosed, and evaporated matter discharged from the drying device an evaporated matter treatment device for condensing the evaporated matter, a suction device constituting the evaporated matter treatment device and for delivering non-condensed gas from the evaporated matter treatment device to another vent treatment device, and a drying device and a dried matter outlet pipe. A heating and drying method for a radioactive waste processing apparatus comprising a solidification processing device that is connected to the drying device and solidifies the dried material discharged from the drying device via the dried material outlet pipe, A device supplies gas sucked from the atmosphere, and after heating the gas with a heating medium flowing through the heating jacket, the heated gas is passed from the drying device to the solidification treatment device via the dried material outlet pipe. A heating and drying method for a radioactive waste processing apparatus, characterized in that the gas is supplied to and circulated through the air, and the gas after the circulation is circulated to the suction device. 2. The heating and drying method for a radioactive waste processing apparatus according to claim 1, wherein the rotary blade is rotated when the gas is heated in the drying apparatus.