Patent Number: 
Section: claims

1. A nuclear reactor, comprising:a reactor driving system including a reactor vessel accommodating a reactor core and a steam generator to which a steam pipe and a water supply pipe are connected; anda reactor safety system including:a releasing isolation vessel accommodating gas and the reactor driving system,an absorbing isolation vessel formed at lower side of the releasing isolation vessel, having a passage formed as a double barrier comprised of a releasing isolation vessel barrier formed at the releasing isolation vessel and having a lower portion opened and an absorbing isolation vessel barrier formed at the absorbing isolation vessel and having an upper portion opened, communicating with the releasing isolation vessel through the passage and accommodating coolant,a transferring isolation vessel formed at upper side of the releasing isolation vessel and on the top of the absorbing isolation vessel and accommodating the gas and coolant,a releasing heat exchanger and an absorbing heat exchanger adjacently disposed to each other within the transferring isolation vessel to exchange heat with each other,a coolant spray pipe having one end in the absorbing isolation vessel and the other end having nozzle in the transferring isolation vessel, spraying coolant to the releasing heat exchanger and the absorbing heat exchanger adjacently disposed to each other,a condensing heat exchanger disposed outside the isolation vessels,a releasing heat exchange channel connected to the reactor vessel and the releasing heat exchanger to circularly distribute coolant,an absorbing heat exchange channel connected to the absorbing heat exchanger and the condensing heat exchanger to circularly distribute coolant, anda releasing isolation vessel communicating pipe formed to connect fluidly an upper portion of the releasing isolation vessel and an upper portion of the transferring isolation vessel,wherein coolant within the reactor safety system is selectively distributed in response to thermal-hydraulic conditions changed depending on a change in pressure within the reactor driving system and whether coolant is leaked to cool the reactor driving system. 2. The nuclear reactor of claim 1, wherein in the reactor safety system, coolant sprayed from the coolant spray pipe absorbs heat from coolant distributed within the releasing heat exchanger to be evaporated,coolant distributed within the absorbing heat exchanger absorbs heat of steam generated by the evaporation to condense the steam and is accommodated into the transferring isolation vessel,a heat transfer is made by a two-phase heat transfer mechanism for transferring heat from coolant within the releasing heat exchanger to coolant within the absorbing heat exchanger by evaporating and condensing coolant sprayed by the coolant spray pipe. 3. The nuclear reactor of claim 1, wherein the coolant spray pipe has one end communicating with the absorbing isolation vessel to be supplied with coolant and the other end provided with a nozzle to spray supplied coolant to the releasing heat exchanger and the absorbing heat exchanger and is provided with a coolant spray valve, andthe reactor safety system further includes:a coolant injection pipe having one end communicating with the transferring isolation vessel and the other end communicating with the releasing isolation vessel to inject coolant accommodated in the transferring isolation vessel into the releasing isolation vessel; anda coolant injection valve provided on the coolant injection pipe. 4. The nuclear reactor of claim 1, wherein the transferring isolation vessel has an accommodating barrier enclosing an area in which the releasing heat exchanger and the absorbing heat exchanger are disposed to accommodate the cold water within the transferring isolation vessel. 5. The nuclear reactor of claim 1, wherein the reactor safety system further includes:a releasing isolation vessel communicating valve provided on the releasing isolation vessel communicating pipe. 6. The nuclear reactor of claim 1, wherein the reactor safety system further includes:a releasing isolation vessel pressure reducing pipe formed to connect fluidly a lower portion of the releasing isolation vessel and a lower portion of the absorbing isolation vessel; anda releasing isolation vessel pressure reducing valve provided on the releasing isolation vessel pressure reducing pipe. 7. The nuclear reactor of claim 1, wherein the reactor safety system further includes:a steam bypass pipe having one end communicating with the steam pipe and the other end communicating with the releasing heat exchange channel to distribute the steam generated by the evaporation of coolant within the steam generator to the releasing heat exchange channel; anda steam bypass valve provided on the steam bypass pipe. 8. The nuclear reactor of claim 1, wherein the reactor safety system further includes:a steam release pipe having one end communicating with the steam pipe and the other end communicating with a space within the releasing isolation vessel to release steam generated by evaporation of coolant within the reactor vessel to the space within the releasing isolation vessel; anda steam release valve provided on the steam release pipe. 9. The nuclear reactor of claim 1, wherein the reactor safety system further includes:a coolant supplement pipe having one end communicating with the releasing heat exchange channel and the other end communicating with a space under a surface of coolant within the absorbing isolation vessel or the transferring isolation vessel to supplement coolant to the releasing heat exchange channel; anda coolant supplement valve provided on the coolant supplement pipe.