Passive containment system
AssigneeNucledyne Engineering Corporation
InventorFrank W. Kleimola
Life of this patent
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Abstract
A containment system that provides complete protection entirely by passive means for the loss of coolant accident in a nuclear power plant and wherein all stored energy released in the coolant blowdown is contained and absorbed while the nuclear fuel is prevented from over-heating by a high containment back-pressure and a reactor vessel refill system. The primary containment vessel is restored to a high sub-atmospheric pressure within a few minutes after accident initiation and the decay heat is safely transferred to the environment while radiolytic hydrogen is contained by passive means.
Claims20
In a boiling water type nuclear reactor power plant comprising a reactor assembly wherein said reactor assembly serves as steam generating means for driving associated turbine means, reactor assembly coolant system means comprising reactor coolant conduit means, reactor coolant circulated within at least a portion of said reactor assembly coolant system means, and a containment structure sealingly enclosing at least said reactor assembly and at least a portion of said reactor assembly coolant system means, the method of affecting containment of said reactor power plant during a failure of said reactor assembly coolant system means within said containment structure and an attendant vaporized loss of said reactor coolant therefrom, said method comprising the steps of providing at least one first fluid body of normally kinematically inert first fluid coolant liquid, normally preventing any direct communication of said first coolant liquid with said reactor assembly coolant system means, providing at least one second fluid body of normally kinematically inert relatively cold second fluid coolant liquid, normally preventing any direct communication of said second coolant liquid with said reactor assembly coolant system means, providing at least one third fluid body of normally kinematically inert relatively hot third fluid coolant liquid, normally preventing any direct communication of said third coolant liquid with said reactor assembly coolant system means, permitting said reactor coolant as is accidentally lost from said failure to enter into a void space defined by said containment structure and vaporize within said void space to thereby increase the pressure within said void space, permitting sufficient quantities of such accidentally lost reactor coolant to enter and vaporize within said void space as to cause said pressure within said void space to increase to a first predetermined magnitude, when said pressure of said vaporized reactor coolant attains said first predetermined magnitude permitting at least a portion of said second coolant liquid and said third coolant liquid to be communicated to said reactor assembly coolant system means as to thereby at least in part replace the volume of said reactor coolant lost therefrom due to said failure, permitting at least a portion of said vaporized reactor coolant in said void space to flow through said first coolant liquid to thereby cause said first coolant liquid through heat transference to absorb some of the energy of said vaporized reactor coolant flowing therethrough, and permitting said vaporized reactor coolant to continue to flow into said first coolant liquid to thereby result in at least substantial displacement of said first coolant liquid and an attendant flow of said first coolant liquid into said void space whereby a back pressure of sufficient magnitude is developed within said void space sufficient to prevent further depletion of said reactor coolant from said reactor assembly coolant system means through said failure.
A safeguard system for a boiling water type nuclear reactor power plant having a reactor assembly with a reactor core having fuel therein and wherein said reactor assembly serves as steam generating means for creating steam for driving associated turbine means and comprises reactor coolant system means, a fluid reactor coolant within said reactor coolant system means, and a containment structure sealingly enclosing at least said reactor assembly and at least a portion of said reactor coolant system means, said safeguard system comprising at least one first body of a first fluid cooling liquid disposed generally internally of said containment structure and within first tank structure means situated within an otherwise free space of said reactor plant, at least one second body of a second relatively cold fluid cooling liquid disposed within second tank structure means situated within an otherwise free space of said reactor plant, at least one third body of a third relatively hot fluid cooling liquid disposed within third tank structure means situated within an otherwise free space of said reactor plant, first conduit means operatively carried by said first tank structure means and adapted for communication between said first fluid cooling liquid and existing free space within said containment structure, second and third conduit means effective for at times completing communication as between said second and third tank structure means and said reactor coolant system means, first pressure responsive means cooperating with said first conduit means for normally preventing flow of said first fluid cooling liquid into said existing free space of said containment structure, said first pressure responsive means being effective to complete said communication through said first conduit means whenever said existing free space within said containment structure attains a predetermined increased pressure arising out of an accidental loss of said reactor coolant as from said reactor coolant system means and into said existing free space of said containment structure, the said completion of said communication between said first tank structure means and said existing free space enabling said first fluid cooling liquid to flow into said existing free space of said containment structure and into heat exchanging relationship with said reactor assembly thereby inhibiting further depletion from said reactor coolant system means of said reactor coolant, and second pressure responsive means effective to normally prevent the flow of said second and third cooling liquids through said second and third conduit means and into said reactor coolant system means, said second pressure responsive means being effective upon the attainment of a preselected pressure differential thereacross occuring subsequent to accidental loss of at least a portion of said reactor coolant into said existing space for completing communication through said second conduit means as to thereby cause said second cooling liquid to flow into said reactor coolant system means to replace with said second cooling liquid such of said reactor coolant as is accidentially lost into said existing space.
Dependencies are inferred from the claim text.