Subatmospheric double containment system
AssigneeStone & Webster Engineering Corp.
InventorsDaniel Gans, Jr., John H. Noble
Life of this patent
Estimating the term…
Abstract
A reinforced concrete double wall nuclear containment structure with each wall including an essentially impervious membrane or liner and porous concrete filling the annulus between the two walls. The interior of the structure is maintained at subatmospheric pressure, and the annulus between the two walls is maintained at a substmospheric pressure intermediate between that of the interior and the surrounding atmospheric pressure, during normal operation. In the event of an accident within the containment structure the interior pressure may exceed atmospheric pressure, but leakage from the interior to the annulus between the double walls will not result in the pressure of the annulus exceeding atmospheric pressure so that there is no net outleakage from the containment structure.
Claims14
A containment structure for a nuclear reactor or the like, including:
- an outer pressure-containing shell member;
- an inner pressure-containing shell member within and inwardly spaced from said outer shell member so as to create an annular space between said inner and outer containment shells;
- means fixedly mounting said inner and outer shell members to a base member forming a foundation for said containment structure;
- first conduit means extending from outside said containment structure through said inner and outer shell members connecting the interior of said inner shell member to a first evacuation system,
- said first evacuation system operating during normal operation to maintain the interior of said inner shell member normally at a subatmospheric pressure;
- second conduit means extending from outside said containment structure through said outer shell member connecting said annular space to a second evacuation system,
- said second evacuation system operating during normal operation to maintain said annular space normally at a subatmospheric pressure which is intermediate that of the interior of said inner shell member and the ambient atmospheric pressure;
- said inner and outer shell members containing sufficient free air volume in the interior and annular containment spaces, respectively, so that during a loss-of-coolant accident, including the maximum credible loss-of-coolant accident, resulting in the release of radioactive gases, liquids and vapors within the containment structure, the pressure of said annular space does not exceed the ambient atmospheric pressure without further operation of said first and second evacuation systems and, consequently, no outleakage of radioactive gases and vapors from the containment structure occurs and such gases and vapors remain in the containment structure after said loss-of-coolant accident without further operation of said first and second evacuation systems until such time as they may be safely vented to the atmosphere.
In a containment structure for a nuclear reactor or the like having an outer pressure-containing shell and an inner pressure-containing shell within and inwardly spaced from the outer shell so as to create an annular space between the inner and outer shells, a method for preventing outleakage of radioactive gases and vapors released into the containment structure during a loss-of-coolant accident, including the maximum credible loss-of-coolant accident, comprising the steps of:
- evacuating and maintaining the interior containment space defined by the inner shell at a subatmospheric pressure during normal operation;
- evacuating and maintaining said annular space at a subatmospheric pressure intermediate that of said interior containment space and the ambient atmospheric pressure during normal operation;
- constructing said inner and outer shell of a size to contain sufficient free air volume in said interior and annular containment spaces so that during said loss-of-coolant accident the pressure increase in said annular space caused by said release of radioactive gases and vapors into the containment structure does not exceed said ambient atmospheric pressure;
- discontinuing evacuation of said interior and annular containment spaces during said loss-of-coolant accident, whereby outleakage of said radioactive gases and vapors from said containment structure is not possible;
- and
- confining said radioactive gases and vapors in said containment structure after said loss-of-coolant accident without further evacuation therefrom until such time as they are capable of being safely vented to the atmosphere.
Dependencies are inferred from the claim text.