JPS62177496A - Transition preventive device of hydrogen, etc. in fast breeder reactor nuclear power facility - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a device for preventing migration of hydrogen, etc. in fast breeder reactor nuclear equipment.

[Prior Art] Normally, in a fast breeder reactor, the heat generated by nuclear fission generated in the reactor core is extracted by liquid sodium, which is passed through as a primary heat medium.
Exchange heat with secondary liquid sodium in an intermediate heat exchanger,
Further, the secondary liquid sodium is led to a steam generator, where it exchanges heat with water, which is a working medium, to generate steam. Alternatively, a plant is being considered in which the intermediate heat exchanger is omitted and primary liquid sodium is directly led to a steam generator to generate steam.

Conventionally, the purification of oxygen 02 and hydrogen H2 mixed in during fuel exchange or the like or through the heat exchanger tubes from the water side has been carried out as shown in FIG.

In FIG. 2, 1 is a reactor vessel, 2 is an intermediate heat exchanger, 3 is a steam generator, and 4 is a turbine.

1 between the reactor vessel 1 and the intermediate heat exchanger 2 by a pump 5.
Secondary liquid sodium is circulated, and a primary cold trap 6 is provided in the primary circulation path. Further, secondary liquid sodium is circulated between the intermediate heat exchanger 2 and the steam generator 3 by a pump 7, and a secondary cold trap 8 is provided in the secondary circulation path.

In the system with the secondary system described above, H2 permeates through the heat exchanger tubes in the steam generator 3 and enters, and a considerable amount of H2 is captured in the secondary cold trap 8, and roughly the intermediate heat exchanger 2.
The remaining hydrogen infiltrated through the primary cold trap 6
It is customary to remove it with

However, in a system that does not include an intermediate heat exchanger, it is necessary to remove all the permeated hydrogen from the water side in the primary cold lap.

[Problems to be Solved by the Invention] Particularly in recent years, due to demands for equipment simplification, there have been attempts to omit the intermediate heat exchanger and directly guide primary liquid sodium to a steam generator to generate steam. However, in this type of trap, all the hydrogen must be removed in the primary cold trap, so its capacity becomes enormous and is almost impossible to implement.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned circumstances, and the present invention provides a double tube (or multiple tube) structure for the heat transfer tubes of the steam generator installed in the fast breeder reactor. Helium gas is circulated through the gap between the heat transfer tubes, and a hydrogen wrap is provided in the circulation path.

[Function] H2 liberated in the water flowing inside the inner tube permeates through the inner tube and leaches into the gap, but the leached H2 is carried to the hydrogen trap by the 1-1e circulation flow and treated, and H2 is removed. The He flow is returned to the gap.

[Example] The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a part of the heat exchanger tube, where the heat exchanger tube 9 is the outer tube 1.
0 and an inner tube 11, and there is a slight gap 12 between the outer tube and the inner tube. The H2 purification system path 13 is connected to the gap 12, and a circulation pump 14 is connected to the second purification system path on this day.
A hydrogen trap 15 and a heater 16 are connected in sequence to the downstream side of the hydrogen trap 15, and a helium gas (He) source 18 is connected to the H2 purification system line 13 via a valve 17.

Next, the effect will be explained.

The circulation pump 14 is driven to circulate He.

The H2 that permeates through the inner tube 11 and leaks into the gap reaches the hydrogen trap 15 along with the circulation flow of He. This hydrogen trap 1
In step 5, H2 contained in He is trapped (or treated) and purified. Since the gas is cooled and processed in the hydrogen trap 15, it is heated by the heater 16 and returned to the gap 12.

In addition, for the initial filling of He, and for the leaked He, the valve 17 is opened and closed as appropriate to supply He from the He source 18.

Moreover, it goes without saying that the heat transfer tube may be a triple tube or a quadruple tube.

[Effects of the Invention] As described below, according to the present invention, the capacity of the primary cold trap provided in the liquid sodium circulation system can be significantly reduced. By adopting this system in installations with intermediate heat exchangers, the capacity of the purification device (cold trap) can be greatly reduced, which has a large impact on plant costs.

It goes without saying that according to the gist of the present invention, it is also possible to prevent harmful gases from diffusing from the primary system to the secondary system or water system.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a conventional example. 1 is a reactor vessel, 3 is a steam generator, 13 is a 1-1e purification system path, 14 is a circulation pump, and 15 is a hydrogen trap.

Claims (1)

[Claims] 1) The heat exchanger tubes of the steam generator installed in the fast breeder reactor have a double tube or multi-tube structure, helium gas is circulated through the gaps between the heat exchanger tubes, and a hydrogen trap is provided in the circulation path. Hydrogen migration prevention device in fast breeder reactor nuclear equipment.