DE2855529A1 - METHOD AND DEVICE FOR DEBORATING PRIMARY COOLING AGENTS OF A WATER-COOLED CORE REACTOR SYSTEM - Google Patents

Description

Method and device for deborating primary coolant in a water-cooled nuclear reactor plant

In a water-cooled nuclear reactor plant, depending on the power and Burned condition of the reactor Boric acid fed into the primary coolant or withdrawn from it. With boron withdrawal, the so-called deboration, primary coolant has so far been removed from the circuit and deionized water (fully demineralized water) is fed in. Several containers are required to store the deionized water. The discharged primary coolant is by means of Evaporator systems separated into water and boric acid concentrate and stored in containers. (Thiemig paperbacks, volume 51 "Pressurized water reactors for nuclear power plants" page 177).

The use of evaporator systems requires a high level of heat. Furthermore, there is a large storage volume for Deionized water required to ensure a certain load change flexibility. '

It is the object of the invention to find a method and a device for deborating primary coolant only a small storage capacity for deionized water and no evaporation is required.

The object is achieved according to the invention in that a partial flow of the primary coolant is passed through a reverse osmosis unit and that the completely demineralized Water is fed directly into the suction line of the volume control pump.

U30Ü26 / CH29

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TPP 68/78

By using the reverse osmosis, known per se from chemical process engineering, to generate the fully desalinated Water, there is no need for a complex evaporator system and the storage containers required for this. The fully demineralized water is on simple, fast and cost-saving way from the fed out Primary coolant obtained and can therefore be used directly for dilution and thus to reduce the boron content in the Primary circuit can be used.

The pressure of the partial flow is advantageously set to the operating pressure of the reverse osmosis unit. With this Measure, the use of a booster pump is avoided.

The device for carrying out the process is thereby
characterized in that a branch leading to the reverse osmosis unit branches off from the bypass line, that a valve group is arranged in the branch and in the bypass line and that the reverse osmosis unit is preceded by a solids filter. This arrangement makes it possible in a simple manner to determine the flow rate and the pressure of the primary coolant flowing to the primary coolant cleaning system and to the reverse osmosis unit

current to adapt to the requirements of the reactor plant. With the solids filter, the primary coolant to be deborated is in
sufficiently pre-cleaned.

The method according to the invention and the device for carrying it out the method is described with reference to the schematic drawing.

A bypass line 1 leads from the primary circuit (not shown) of a water-cooled nuclear reactor installation
Primary coolant cleaning system 2. A valve group 3 is used to regulate the flow and reduce the pressure of the primary coolant

TPP 68/78

This arrives via the suction line 4 of the volume control pump 5, which is practically a continuation of the bypass line 1 cleaned primary coolant back into the primary circuit of the Reactor plant. On the suction side of the volume control pump is a volume compensation tank 5 and on the pressure side is a valve 7 for Feed-in regulation provided. A branch 8, also arranged on the pressure side, with a control valve 9 is used for Sealing water supply to the primary circuit pumps. Seen in the direction of flow, a branch 10 branches off in front of the valve group 3 from which is also equipped with a valve group 3a for flow control and pressure reduction. Depending on the Position of the valve group 3 »3a, different amounts flow through the bypass line 1 and / or the line 10. With the Valve group 3a, the pressure in the line 10 is kept at the operating pressure of the reverse osmosis unit. That in that Strand 10 flowing primary coolant is in a solids filter 11 pre-cleaned and then flows through a reverse osmosis unit 12. When flowing through the reverse osmosis unit falls full.itsalztes water as permeate which reaches the suction-side area of the volume control pump 5 via line 13. Concentrated boric acid leaves the reverse osmosis unit

via a line 14 and opens into a container 15 to e.g.

to find use for a boronization of the primary coolant.

With the help of a flow measurement from an analytical

device 16 and a control valve 17 »the concentration ; tration of boric acid in line 14 is regulated. The pressure ■ Solutions 18,19,20 and the flow measurements 21,22,23 are used to monitor, adjust and control the device.

With the method described, the deborating of the primary coolant is achieved with simple means.

030026/0429

Claims (4)

TPP 68/78 , 2855523 Claims
r \ i Method for deborating primary coolant of a water-cooled nuclear reactor plant, wherein the boron is removed during the primary coolant cleaning phase, characterized in that a partial flow of the primary coolant is passed through a reverse osmosis unit (12) and that the demineralized water which is separated off is passed directly is fed into the suction line (4) of the volume control pump (5). 2. The method according to claim 1, characterized in that the pressure of the partial flow to the operating pressure of the reverse osmosis unit is set. 3. The method according to claim 1, characterized in that by means of one of the reverse osmosis unit (12) downstream flow control, the concentration of the boric acid flowing out is set to the value required for storage or boronization. ί 4. A device for carrying out the method according to claim 1 with a bypass line leading to the coolant cleaning system, characterized in that from the bypass line (1) a line (10) leading to the reverse osmosis unit (12) branches off, that in the line (10 ) and a valve group (3, 3a) for flow control and pressure reduction is arranged in the bypass line (1) and that the reverse osmosis unit (12) is preceded by a solids filter (11). 030026/0429 / ι: / P 1 ■ 'ι ι / ·: ·· "-Q-I, -,