Aparatus and method for dismantling for heavy water reactor facilities

A method for dismantling a heavy water reactor facility including a calandria that includes a main shell, subshells connected to opposite ends of the main shell, and an end shield, a calandria vault that receives the calandria, a cover assembly that is disposed in an upper portion of the calandria vault to cover the calandria, a pressure tube that horizontally passes through the inside of the calandria, and a calandria tube that surrounds the pressure tube, comprising:

• removing the pressure tube and the calandria tube;
• dismantling the cover assembly by opening an upper portion of the calandria vault;
• cutting the periphery of a first nozzle portion of the calandria connected to an upper end of a first pipe disposed inside the calandria by using a first cutting device;
• fixing the cut first fixing portion by using a fixing and withdrawing device;
• cutting a first support portion of the calandria, connected with a lower end of the first pipe connected to the first nozzle portion by using a second cutting device;
• and
• drawing out the first nozzle portion and the first pipe by using a fixing and withdrawing device.