Load and unload of Spent fuel in Nuclear Power Plant

1. 1
Operation and Maintenance of NPP
Please try describe process of unloading reactor core (step by step) and transfer fuel from
Reactor Building to spent fuel pond in Fuel Building
The reactor unloading of NPPs is carried out in the loading and unloading area for reactor fuel
assemblies by joint operation of equipment in the fuel handling and storage system.
Step 1: -
The fuel manipulator crane picks up the fuel assemblies to be unloaded from the reactor
in the refuelling cavity and transports them to the fuel building through fuel transfer tube and
gate valve.
Step 2: -
The fuel assembly is transported to the fuel building by the transport trolley.
Step 3: -
With the help of pond fuel handling machine, the fuel assemblies are moved to fuel
storage racks.
[The spent fuel storage rack is installed inside the spent fuel storage pool. Because of a large number
of irradiated fuel assemblies with high radioactivity and residual heat are stored in such rack for a long
period, the issues concerning subcriticality, thermal hydraulics and earthquake resistance arising
therefrom shall be taken into full account and such rack shall be designed according to relevant
standards.

2. 2
The centres of storage units of the spent fuel storage racks are arranged at equal intervals (larger than
the safe distance) and all the storage units can store enough fuel assemblies with several storage units
as the standby. The pool is equipped with sufficient safety features to ensure the nuclear safety.]
Step 4: -
After long period remove of residual heat form the fuel, there are transferred to
irradiated fuel transport flask by mean of fuel building crane.
Step 5: -
This irradiated fuel transport tank are loaded into vehicles for the safe disposal with
help of fuel building crane.
The reactor unloading in the nuclear power plants is performed by unloading the in-
core fuel assemblies in the pool filled with borated water group by group All operations are
conducted in the borated water, to ensure the criticality safety and radiation protection safety
during fuel unloading.
Submitted by
Ojes Sai Pogiri (k-5870)
Ramabrahmendra Kommanaboina (302472)