Fuel handling machine

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. 

FBTR operating experience has improved the confidence level in the design and operation of core, sodium systems, control rod drive mechanisms, fuel handling machines, steam water system and SG leak detection system. 

A 35.0 mm (1.38 in.) diameter handling hole, located at the center of the element, extends down about one-third of the height, with a ledge where the grapple of the fuel handling machine engages. 

Figure 1 shows the location of the facility for sodium cleaning in the nuclear island. The core components are handled by fuel handling machines where as the primary components are handled by respective flask. The components that are to be decontaminated are removed from the reactor when the reactor is in shutdown condition. The handling of the core components is based on fixed time duration and interval in the reactor. For the primary components, it is as and when required. 

In general, items removed from the reactor and intended for re-use, such as the PFR fuel handling machine, are first allowed to drain, and then stored in a containment padded with argon. There may, if the storage is long, be some oxide formation, but this will dissolve in the sodium on re-immersion. 

Fuel handling time in FBR is not governing the duration of shutdown of a plant Therefore, parallel operation of fuel handling machines is not needed (10-12 d/a shutdown for fuel handling, 40-50 d/a shutdown for maintenance)... 

For a 300 MW(e) power plant ANSALDO can provide a large share of supply as reactor assembly, power channel, fuel handling machine, reactor vessel, steam generators, turbine/generator group. 

As for unauthorized use of the fuel-handling machine, this kind of machine is a temporary system for the 4S and would be shared among several 4S sites. There would be no available machine for fuel assembly handling during the operation. 

In addition, procedure and/or administrative cotnrols will be provided to ensure safe operation for the fuel building overhead crane and spent fuel handling machine, and to control the safe load path and safe lifting practice. 

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 components of the refuelling machine, fuel transfer system and fuel handling machine that perform significant lifting operations are provided with redundant load paths ... 

The fuel handling machine hoists are supplied with redundant paths of load support so that failure of any one component will not result in a free fell of the feel assembly. When redundant paths are not practical, conservative safety factors will be applied (see Section 9.1.4.3.3 ofReference 6.1). 

The fuel handling machine, and its associated fuel handling tool, can only place a fuel assembly in the new fuel rack, spent fuel racks, fuel transfer system, new fuel elevator, spent fuel cask, fuel inspection/repair station, or rail car bay traveller. 

When a fuel assembly is raised or lowered, interlocks provide confidence that the fuel handling machine can apply only loads that are within safe operating limits. 

On the spent fuel pool side, the fuel transfer system is interlocked with the fuel handling machine. The fuel transfer system cannot be operated until the loaded fuel handling machine hoist is at the up limit, the empty tool is clear of the up-ender, or the fuel handling machine is moved away from the fuel transfer system area. An interlock is provided from the fuel handling machine to the fuel transfer system to accomplish this. 

The fuel handling machine is provided with a number of features that prevent the jamming of fuel assemblies or the snagging of lifting equipment (see Section 9.1.4.3.3 of Reference 6.1), including ... 

The fiiel handling machine hoist is prevented from moving in the transfer machine zone unless the fuel transfer machine up-ender is vertical. An interlock is provided from the fuel transfer system to the fuel handling machine to accomplish this. 

These features include the charging and discharging of fuel from the bottom of the reactor vessels where the temperature is lower, the provision of separate fuel-handling machines at the top of the vessels if required and the provision of remotely adjustable rods for the maintenance of reactivity balance. 

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. 

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. 

In the construction cost for one module, 25% is for equipment in common with the other modules such as fuel handling machines, and 30% of the cost is for design and analyses, etc. In the 4-module power plant, about a 40% reduction of the cost could be achieved as shown in Fig. XXII-3. Figure XXII-4 illustrates the cost reduction approach of the MDP. The construction costs of a 2" 4-module plant would be competitive with the construction cost of a large-capacity LWR. 

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

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