RU142177U1 - DEVICE FOR CONTROL OF SATURATION OF ADSORBER BY TRITED WATER - Google Patents

Abstract

1. A device for monitoring the saturation of the adsorber with tritiated water, characterized in that the latter is equipped with a control and protective attachment, which is a container with a zeolite with a radiation counter placed inside, connected to a recording device located in the visual accessibility zone. 2. The device according to claim 1, characterized in that the end counter SBT-13 is used as a radiation counter.

Description

The utility model relates to means for monitoring the moment of complete saturation of the adsorber (mining) in devices for catalytically adsorption extraction of tritium from gases used to clean ventilation emissions in the nuclear industry and energy.

There is also a method for determining the activity of tritium in a container with radioactive waste (p. RF No. 2225016, G01T 1/167, publ. 02.27.2004), which describes a device for implementing this method, which includes a container containing radioactive waste placed in PVC bags so that there is free space in the container, a leak detector equipped with a mass spectrometer, the outlet pipe for sampling has a capacity and allows gas samples to be taken from the free space of the container. The signal provided by the leak detector depends, among other factors, on the magnitude of the flow of isotopic gas and the pressure of the isotopic gas in front of the leak. A discharge tube through a valve is connected to an activated carbon trap immersed in liquid nitrogen.

This device is designed to determine the amount of tritium in radioactive waste.

A known adsorber (p. RF No. 96338, B01D 53/04, publ. 07/27/2010), containing as an adsorbent monolithic zeolite blocks in the form of cylinders, the housing is equipped with a central annular protrusion with sealing elements at both ends to which the zeolite adjoins blocks, caps for axial movement are fitted with fittings for supplying and discharging the processed gas medium.

The disadvantage of this device is that the design of the adsorber does not allow timely fixation of the moment preceding the breakthrough of the NTO through the adsorber (the moment of working out the adsorber) in order to replace it in time, which leads to the likelihood of large quantities of NTO entering the atmosphere or the cleaned volume.

This device is taken as a prototype.

The objective of the utility model is the timely recording of the complete saturation of the adsorber (mining) with oxidized tritium (DTO, NTO, T ₂ O) in order to prevent the release of tritium oxide into the environment, which is 10 ⁴ times radiotoxic to gaseous tritium.

The technical result achieved using this utility model:

- elimination (timely prevention) of the release of tritium oxide (DTO, NTO, T ₂ O) into the environment during catalytic-adsorption gas purification from tritium (T);

- compactness and simplicity of the device that fits into the gas purification system from T.

The technical result is achieved by the fact that in the device for controlling the saturation of the adsorber with tritiated water, the latter is equipped with a control and protective attachment (CTC), which is a container with a zeolite with an internal radiation counter connected to a recording device located in the visual accessibility zone. An SBT-13 end counter can be used as a radiation counter.

When gas is purified from T by its catalytic oxidation followed by adsorption of the formed tritiated water (DTO, NTO, T ₂ O) with solid adsorbents (zeolites, silica gel, activated carbon), it is extremely important to fix the moment preceding the passage of NTO through the adsorbent (the moment of adsorption testing) in order to replace it in a timely manner. Otherwise, the probability of the release of large amounts of oxidized tritium (NTO) into the atmosphere is not ruled out, since NTO is 10 ⁴ times more radiotoxic than gaseous T.

Existing methods for the degree of saturation of solid adsorbents with tritium (H ₂ O) or deuterium (D ₂ O) water: dielectric, gravimetric, chemical, radiation, etc., cannot be used for specific conditions of NTO adsorption due to their discreteness, cumbersomeness and non-efficiency .

The adsorption dynamics is described by the Shilov equation, according to which the adsorber is saturated layer by layer with H ₂ O vapor. The adsorption front moves along the length of the adsorber from entrance to exit. If we fix the moment of approach of the adsorption front to the exit from the adsorber, then we can timely fix the moment of development of the adsorber, i.e. prevent the release of NTO into the atmosphere.

For NTO, the position of the adsorption front can be determined by recording the bremsstrahlung of β particles of T in the adsorbent (zeolite, silica gel, etc.). If a bremsstrahlung detector is placed in the adsorbent layer at the outlet of the adsorber, then as the first layers (at the outlet) of the adsorbent become saturated, the radiation will not be recorded due to the small path of the bremsstrahlung quanta T in the adsorbent. When the NTO layer saturates towards the detector, the radiation will be detected.

The registration of the bremsstrahlung of β-particles T can be carried out by end counters with a thin window (3 ... 5 g / cm ² ), NaJ scintillators or organic polystyrene based, as well as semiconductor detectors. The SBT-13 end counter, which has a relatively small background and small dimensions, was experimentally selected.

In FIG. 1 shows a device for controlling the saturation of an adsorber with tritiated water, FIG. 2 - change in the readings of the device P103 for recording the adsorption front of the NTO and the device SP-1M, where

1 - radiation counter,

2 - zeolite,

3 - capacity

4 - adsorber,

5 - recording device.

The bullpen is a tank 3, equipped with generatrix fittings. The input of the bullpen is connected to the output of the adsorber 4. The tank 3 is filled with zeolite 2 NaA (0.5 l). The counter window 1 of the SBT-13 in the bullpen is located perpendicular to the adsorption front, therefore, the recording device 5 is triggered when ~ 20% of the bullpen zeolites are saturated, the rest of the zeolite performs protective functions, preventing the NTO from slipping.

It is not practical to introduce the radiation counter 1 directly into the adsorber 4, since the adsorber 4 must be regenerated at a high temperature (up to 600 ° C), which requires the extraction of the counter 1 before regeneration of the adsorber 4. Therefore, it is proposed to monitor the saturation of the NTO adsorber using a protective and protective attachment (CTC) ) to the adsorber 4. KPZ - capacity 3 with the NTO adsorbent with the SBT-13 counter 1 placed inside (Fig. 1). In this case, the recording device 5 connected to the counter 1 is triggered when the adsorption front moves from the adsorber 4 to the bullpen.

The performance check of the bullpen with a recording device was carried out during purification from T argon at a concentration of tritium at the inlet to the catalyst of 10 ⁵ ... 10 ^-1 Ku / l. Moreover, the content of NTO at the outlet of the adsorber was 10 ^-6 ... 10 ^-5 Ku / l. The recording device recorded the output of the NTO adsorption front from the adsorber to the bullpen. As the adsorption front moves along the counter window, the readings of the recording device increase to 90 pulses / min. At the same time, the device that records the concentration of T at the output of the adsorber with short-circuit breaker (SP-1M) does not record an increase in readings (NTO slip) (see figure 2). The verification results confirm the efficiency and reliability of recording the moment of complete saturation of the NTO absorption.

Claims (2)

1. A device for controlling the saturation of the adsorber with tritiated water, characterized in that the latter is equipped with a control and protective attachment, which is a container with a zeolite with a radiation counter placed inside, connected to a recording device located in the visual accessibility zone. 2. The device according to p. 1, characterized in that the end counter SBT-13 is used as a radiation counter.

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