Ex-vessel transfer machine

After the reactor is shut down, the ex-vessel transfer machine (EVTM) transfers a new fuel assembly, in a sodium-filled CCP, from the EVST to the reactor through a 44.5 hatch in the reactor containment building (RCB) wall. When the new fuel assembly arrives at the reactor, it is discharged from the EVTM into a transfer position on the periphery of the reactor core in the reactor vessel. 

Ex-vessel transfer machine (EVTM). This rail-mounted transfer cask moves core component pots (CCPs) with fresh fuel and other core components from the EVST to the reactor vessel and moves CCPs with SNF and other core components from the reactor vessel to the EVST. The CCPs are small vessels used to transfer fuel and other components in a temperature-controlled sodium environment. The EVTM is also used for fresh fuel, SNF, and other transfer operations within the reactor service building and remains in the reactor service building during reactor operations. 

The core components are spent fuel assembly (SA), irradiated blanket SA and irradiated absorber SA. There are 94 core SA to be cleaned from sodium in eight months full power reactor operation. The core SA coming out of the reactor is handled by cell transfer machine. This machine picks up the core SA from the ex-vessel transfer position and keeps it in the washing vessel. The flow sheet of the SA washing is shown in Fig. 3. 

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. 

---