In-vessel handling machine

An overall plan view of the FFTF reactor refueling facilities is shown in Fig. 5.2. The principal exreactor component is the closed loop ex-vessel machine (CLEM), shown in Fig. 5.3. The CLEM loads all components into the reactor vessel and removes all components from the reactor core. Fresh driver fuel and all SNF is transferred to and from the reactor in a core component pot (CCP) that can be inserted or removed through one of three fuel transfer ports in the reactor vessel top cover. The in-reactor components consist of three in-vessel handling machines (IVHMs) plus the three in-vessel storage modules. The FFTF requires three IVHMs because of closed test loops in the reactor core which interfere with direct access to the entire reactor core with one machine. 

Reactor refueling systems. A series of systems associated with the reactor and reactor vessel are required for refueling. Outside the reactor vessel these include three fuel transfer ports, eight test position spool pieces, two floor valve ad ters and the test transfer port, and the reactor containment building cranes. Inside the reactor vessel are three in-vessel handling machines (IVHMs) and three invessel storage modules. Three IVHMs are required because of the mission of the FFTF that requires closed test loops in the reactor core which interfere with direct access to die entire core with one machine. 

Fig. A.12. Plan view showing locations of in-vessel handling machines. 

Fig. A. 13. Reactor cutaway showing in-vessel handling machines.

In-vessel handling is carried out using two rotatable plugs and an offset (fixed) arm type fuel handling machine (IVTM). An ultrasonic scanner is provided in order to check projection of any SA/absorber rods above the top of the core before starting in-vessel transfer operation. Additionally, strict administrative control on interlocks is to be provided. An Inclined fuel transfer machine (IFTM) is used to transfer the subassemblies from the main vessel to outside. 

Considerable progress has been made in the design of component handling systems. For handling core subassemblies within the main vessel, transfer arm type In-vessel Transfer Machine (IVTM) has been selected. For transporting core subassemblies towards the external storage,... 

Two IHXs and four EM primary pumps are suspended in the reactor vessel by the reactor closure. Primary control rod drives, ultimate shutdown rod drives, in-vessel instrumentation, and an in-vessel transfer machine (IVTM) for fuel handling are suspended from the rotatable plug in the closure [3]. The reactor closure with major equipment is shown in Figure 6.9. 

Spent fuel handling. Spent fuel is taken from the core and transferred to a tank in the lower part of an in-vessel transfer machine. This is done by a fuel handling machine of the pantograph fixed-arm type. After the fuel has been removed from the reactor vessel with an exvessel transfer machine, it is transferred through a containment equipment hatch. Later it is stored in a fuel cooling pond after sodium cleaning. 

If it is assumed that the in-vessel fiiel-handling machine can be constructed of the same advanced alloy as the reactor vessel (750°C operating temperature), then it is reasonable to expect that the LS-VHTR design of the in-vessel fiiel-handling machine could closely resemble the design proposed for the GT-MHR machine (General Atomics, 1996). This machine is very similar to the Fort St. Vrain machine (Sect. 4.1.2) except the design has been updated to reflect (1) improvements in selected components (such as instrumentation and control) and (2) what was learned in Fort St. Vrain operations. 

The lower portion of the in-vessel section is exposed to reactor sodium and the cover gas. It is installed and removed using the auxiliary handling machine, which provides a shielded inert-gas environment. 

The plant layout of a LSPR plant is shown in Figures XXV-19 and XXV-20. The conventional fuel handling system is not available for a long life core. However, maintenance handling machines and maintenance spaces are accommodated and the pullout space necessary for mechanical pump impellers and purifying units is provided. When the reactor vessel lifetime expires, the current assumption is to comply with the need to exchange the reactor vessel with a new one. 

The main equipment handling devices within containment are the polar erane, equipment hateh hoist and maintenanee hatch hoist. Fuel is moved between the reactor vessel and the fuel transfer system by the refuelling machine. Outside containment the fuel is moved using the fuel handling machine, the casks by the cask handling crane, new fuel by the new fuel elevator and operations in the railcar by its dedicated gantry crane. 

The shield plug, fuel handling machine, ex-vessel storage tank and other major components were assembled in advance at the factory, and assembly tests were conducted to confirm the performance of system prior to assembly on site. 

Refueling system No in-vessel fuel handling machine... 

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