JPH01195398A - Operation method for used resin transporting device - Google Patents

Abstract

PURPOSE:To operate a device without replenishing water to prevent the occurrence of secondary waste by flowing a used resin into a storage tank together with transporting water and leaving them for a certain time to separate them to the used resin and supernatant water and transporting supernatant water to a gathering tank to treat it. CONSTITUTION:The used resin from a power plant is flowed into a storage tank 1 together with transporting water at any time. When the level of the used resin in the storage tank 1 detected by a resin level detector 11 is lower than a prescribed value at this time, a decant pump 5 is started, and it is operated until supernatant water is transported to a low-conductibility waste liquid gathering tank 2 to output a low level value signal from a water level detector 16. A decant valve 4 is closed at the time of stopping the decant pump, and this operation is repeated. The used resin is accumulated in the storage tank 1 by repeating this operation; and when the level of the used resin reaches a prescribed value, the resin level detector 11 outputs a signal to inform an operator of this state. The decant pump 5 is started after attenuation of the radiation level of the used resin, and the used resin is loosened, and the mixture of the used resin and supernatant water is transported to a solidifying device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method of operating a used resin transfer device for transferring spent resin generated in a nuclear power plant or the like to a solidification device or the like.

(Prior art) In nuclear couplers such as nuclear power plants, it is necessary to constantly purify reactor coolant, double water after turbine drive, fuel pool water, etc., so ion exchange resins etc. are used as purification materials. It is used.

When these purification materials lose their purification ability such as ion exchange ability, they are stored as used resin in the storage tank of radioactive waste processing equipment.
After being stored for a certain period of time to attenuate the radiation level, it is transferred to an assimilation facility for assimilation treatment. Fig. 2 is a schematic diagram of a conventional used resin transfer device, in which the supernatant water in the storage tank is transferred to the low-conductivity waste liquid collection tank 2 near the central soil on the side of the storage tank 1.
A decant pipe 3 is installed for transferring to
This decant pipe 3 is connected to a low conductivity waste liquid collection tank 2 via a decant valve 4 and a decant pump 5. A transfer pipe 6 for transferring the used resin in the storage tank 1 to the assimilation device is provided at the lower side of the storage tank 1, and the transfer pipe 6 is equipped with a storage tank outlet valve 7 and a resin transfer pump 8.
is attached and communicated with an assimilation device (not shown).

In the storage tank 1, there are a make-up water nozzle 9 and a make-up water valve 10 for supplying make-up water as transfer water during used resin transfer.
A resin level detector 11 and a level indicator 12 for detecting the surface position of the settled used resin are also provided.

In such a used resin transfer device, reactor coolant in the plant and used resin for double water purification flow into the storage tank 1 together with transfer water. After the inflowing used resin is allowed to settle for a certain period of time, the supernatant water is transferred from the decant pipe 3 to the low conductivity waste liquid collection tank 2 via the decant valve 4 and decant pump 5. Note that the transferred supernatant water is reused as plant water after removal of solid content and ion exchange treatment by a low conductivity waste liquid treatment device (not shown).

By repeating this cycle of used resin inflow and supernatant water transfer,
Used resin is accumulated in the storage tank 1, and when the surface position reaches a predetermined height, this is detected by the resin level detector 11, and the level indicator 12 notifies the operator of this fact. The operator prohibits the flow of new spent resin into the storage tank 1 and enters a storage decay period to attenuate the radiation level of the spent resin in the storage tank 1. After reaching a predetermined radiation level, the make-up water valve 10 is opened to supply make-up water as transfer water from the make-up water nozzle 9, and an in-tank stirring pump (not shown) is inserted into the storage tank 1 in order to transfer it to the assimilation device. Insert the resin, stir the used resin, peel it off, operate the resin transfer pump 8, and operate the resin transfer pump 8.
is opened and transferred to the assimilation device through the transfer pipe 6 for assimilation treatment.

(Problems to be Solved by the Invention) When transferring the used resin in the storage tank 1 to the assimilation device as described above, the resin is loosened by an in-tank stirring pump in advance, and the resin is transferred into the storage tank 1 in order to transfer the resin. It is necessary to inject make-up water, which increases the amount of secondary waste generated. Furthermore, since the tank stirring pump is moved in and out of the storage tank 1, there is a problem in that the radiation exposure of workers increases.

The present invention has been developed in view of these circumstances, and does not require make-up water or an in-tank stirring pump when transferring used resin, thereby suppressing the generation of excess secondary waste and reducing worker exposure to radiation. The object of the present invention is to provide a method for operating a used resin transfer device that does not require any prior art.

[Structure of the Invention] (Means for Solving the Problem) The present invention includes a storage tank for storing used resin and transfer water, and a waste liquid transfer system for transferring supernatant water from the upper center of the side of the storage tank to a collection tank. A circulation path is provided with a transfer path equipped with a pump and an on-off valve, and an on-off valve is provided at the bottom of the side of the storage tank from the discharge port of the waste liquid transfer pump to stir the spent resin in the storage tank, and a circulation path on the side of the storage tank. A transfer path equipped with a resin transfer pump and an on-off valve is provided to transfer the used resin from the lower part to the assimilation device.

The storage tank will be equipped with a supernatant water level detector and a resin level detector.

(Function) The used resin flows into the storage tank together with the transfer water and is left for a certain period of time to separate into the used resin and supernatant water, and the supernatant water controls the operation of the waste liquid transfer pump based on the water level signal from the water level detector. and then transferred to a collection tank for treatment. As this operation cycle of inflow and transfer is repeated, used resin accumulates in the storage tank, and the surface position of this is detected by a resin level detector.
When a predetermined value is reached, the inflow of used resin from the outside and the transfer of supernatant water to the low conductivity waste liquid collection tank are stopped, and the waste liquid transfer pump is operated to collect the spent resin using the supernatant water in the storage tank. After stirring and combing, the resin transfer pump is operated to transfer the used resin to the solidification device.

(Example) An embodiment of the present invention will be described with reference to the drawings.

It should be noted that the same parts as those in the prior art described above will be designated by the same reference numerals and detailed explanations will be omitted. Figure 1 is a configuration diagram of the spent resin transfer device.Storage tank 1 stores 1:1 volume of used resin transported together with transfer water from various parts of the nuclear power plant. A decant pipe 3 is installed nearby, and the supernatant water in the tank is transferred to the low conductivity waste liquid collection tank 2 via a decant valve 4 and a decant pump 5.
Transfer path and storage tank 1 by the first outlet valve 13 to be transferred to
A circulation path with a second outlet valve 15 is provided in the circulation pipe 14 attached to the lower side of the tube. Furthermore, a resin level detector 11 and a level indicator 12 for detecting the surface position of the used resin, and a supernatant water level detector 16 are installed in the upper part of the storage tank 1. On the other hand, a transfer pipe 6 is drawn out from the lower side of the storage tank 1 via a storage tank outlet valve 7 for transferring the spent resin in the tank to an assimilation device, and a resin transfer pump 8 is connected to this transfer pipe 6. is installed. Each pump and valve is provided with a prime mover (not shown), a power source, and a switch (not shown) for driving and controlling the pump, and operation and stop signals can be obtained from these.

Next, the effects of the above configuration will be described. It is assumed that each valve is initially closed and the pump is stopped. The used resin from inside the power plant is stored in storage tank 1 along with the transferred water.
flows into. At this time, whether the high value of the water level detector 16 is Shintan,
When the resin level detector 11 outputs a signal, this signal issues an inflow stop command, but in other cases, when this inflow operation ends, a transfer completion signal is issued from the transfer source.

After this, the sedimentation time of the resin has elapsed, and the level of the supernatant water measured by the water level detector 16 is not at a low value, and the resin level detector 11
The level of used resin in storage tank 1 detected by
If the value is below the predetermined value, the decant pump 5 is activated, the decant valve 4 and the first outlet valve 13 are opened, and (a) the water is transferred to the low conductivity waste liquid collection tank 2 and the water level detector 16 is set to low. Drive until it emits a position signal. When the decant pump 5 is stopped, the decant valve 4 is closed and this process is repeated. By repeating this operation, used resin is accumulated in the storage tank 1, and when a predetermined value is reached, the resin level detector 11 issues a signal.
The level indicator 12 displays this to notify the operator.

If the water level detector 16 is not outputting a low position signal at this time, stop the inflow from the outside, wait for the radiation level of the used resin to decay, close the first outlet valve 13, and turn on the decant pump 5. Start up, decant valve 4 and second outlet valve 15
As a result, in the storage tank 1, supernatant water is circulated into the used resin by the decant pump 5, stirring the used resin and loosening the used resin.

Thereafter, the resin transfer pump 8 is operated, the storage tank outlet valve 7 is opened, and the mixture of used resin and supernatant water is transferred to the assimilation device.

Naturally, at this time, the supernatant water is used both for stirring the used resin and for transferring water, so there is no need to supply new make-up water. Note that the detection position of the resin level detector 11 is located below the installation position of the decant pipe 3, and the detection position of the water level detector 16 is
If the lowest value of is selected above the mounting position of the decant pipe 3, it is possible to always secure the supernatant water required for stirring and transfer when the resin level detector 11 is in operation.

[Effects of the Invention] As described above, according to the present invention, when transferring resin from a storage tank in which used resin is accumulated, it is possible to operate without using new make-up water with an apparatus that is not much different from the conventional equipment, thereby eliminating unnecessary secondary water. No waste is generated. Furthermore, since there is no need to insert and remove a stirring pump into and out of the storage tank for each transfer operation, the amount of radiation exposure of workers can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a used resin transfer device of the present invention, and FIG. 2 is a schematic diagram of a conventional used resin transfer device. 1... Storage tank 2... Low conductivity waste liquid collection tank 3... Decant piping 4... Decant valve 5...
...Decant pump 6...Transfer piping 7...Storage tank outlet valve 8...Resin transfer pump 11...
Resin level detector 12...Level indicator 13...First output 1" valve 14...Circulation piping 15...Second outlet valve 16...Water level detector.

Claims (1)

[Claims] There is a storage tank that stores the used resin that flows in with the transfer water, and the supernatant water separated here is sent to a collection tank, and in the spent resin transfer device that transfers the used resin to a solidification device, etc., the supernatant water in the storage tank is The system detects the water level and controls the operation of the waste liquid transfer pump to transfer the waste to the collection tank, and when the accumulated level of used resin in the storage tank reaches a predetermined value, used resin is brought into the storage tank from outside. Stop the transfer of supernatant water to the collection tank, operate the waste liquid transfer pump to loosen and stir the used resin in the storage tank, and operate the resin transfer pump to transfer the spent resin and supernatant water to the solidification equipment. Features: How to operate a used resin transfer device.