JPS6318156B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing a large structure, and particularly to a method for installing a reactor vessel of a tank-type fast breeder reactor.

Fast breeder reactors generally use liquid metal such as liquid sodium as a coolant, and the cooling system in which the liquid metal circulates is divided into a primary cooling system and a secondary cooling system. The liquid metals in the primary cooling system and the secondary cooling system are in a heat exchange relationship in the intermediate heat exchanger.

A so-called tank-type fast breeder reactor houses the circulation pump and intermediate heat exchanger that make up the primary cooling system, in addition to the reactor core loaded with fuel, in a single reactor vessel, and has certain features. However, the reactor vessel would be very large.

To be more specific, the reactor vessel of a tank-type fast breeder reactor, in a practical or demonstration reactor, has a diameter of more than 20 meters and weighs nearly 1,000 tons, so special measures are required to install it. It takes.

In addition, on the outside of the reactor vessel (approximately bowl-shaped), a protective vessel of approximately the same shape is provided to surround the reactor vessel in case of coolant leakage, and both vessels are further equipped with a shielding wall. The difficulty of the installation work is extremely great because the equipment is suspended and supported in a storage room surrounded by the surrounding area.

For example, when attempting to lift the bottom of a reactor vessel using multiple temporary jacks, the support reaction force of the reactor vessel becomes localized, making it necessary to reinforce that area in advance, which further increases the weight and manufacturing cost. There is a problem of increasing

Further, since the temporary jack cannot be installed on the protective container, it is necessary to make a hole in the protective container and finally plug the hole, which requires a lot of time for the work and inspection.

The present invention was made in view of the above-mentioned circumstances, and after installing an outer protective container, an expansion bag is temporarily placed at the bottom of the protective container, a reactor vessel is placed on top of the expansion bag, and the expansion bag is then inflated. It provides a method for lifting, positioning, and installing a nuclear reactor vessel.

Hereinafter, the present invention will be explained based on examples.

In the figure, concrete shielding walls 1 and 2 and a floor 3 have already been poured to form a storage room 5.

An inwardly facing shelf 7 is also formed at the upper part of the shielding walls 1, 2. A bowl-shaped protective container 9 manufactured at another location, for example, in a factory, is carried by a transportation and lifting device (not shown) such as a crane and suspended, and the flange 11 at the outer edge of the upper opening is placed on a shelf. placed on top of 7.

The inflatable bag 15 attached to the end of the fluid or air supply hose 13 is then deflated and placed at the bottom of the protective container 9. At that time, hose 1
Leave the tip of number 3 outside.

Next, a bowl-shaped reactor vessel 17 (fabricated at a different location like the protective vessel 9) is temporarily placed in the protective vessel 9, and the roof slag 19 is carried into the upper part of the containment chamber 5, and its outer edge is Place it on shelf 7. The roof slag 19 supports the circulation pump and intermediate heat exchanger (none of which are shown) of the primary cooling system, and covers the reactor vessel 17.

Finally, pressurized air is supplied from the hose 13 to the air bag 15 to inflate it, lift the container 17, align the upper edge of the container 17 with the lower edge of the roof slug 19, and join them together by welding. With this operation, the reactor vessel 17 is suspended and supported from the shelves 7 of the shielding walls 1 and 2 via the roof slag 19, and the installation is completed. Let the air out of the air bag 15 and remove it.

As explained above, according to the present invention, since the reactor vessel is lifted by inflating an expansion bag such as an air bag, excessive local stress is not generated in the reactor vessel or protective vessel, and special processing is not required for these. Since the expansion bag is not required and can be deflated and easily removed, a large reactor vessel can be installed easily and in a short time.

[Brief explanation of the drawing]

The drawing is an explanatory view showing the state of the reactor vessel at one stage of the method of the invention. 5... Storage room, 7... Shelf, 9... Protective container, 1
3...Hose, 15...Air bag, 17...Reactor vessel.

Claims (1)

[Claims] 1. A protective container is suspended and supported in a containment chamber, an expansion bag connected to the tip of a fluid supply hose is temporarily placed at the bottom of the protective container, a reactor vessel is placed in the protective container, and then the expansion bag is removed. 1. A method for installing a nuclear reactor vessel, the method comprising: adjusting the position of the reactor vessel by levitating the reactor vessel by injecting fluid into the reactor vessel.