Reactor Containment Building Spent Fuel Pool Filter Vent

Abstract

A nuclear containment atmospheric filter including dedicated piping, valves, a control system and a chemical injection system to facilitate the use of a commercial nuclear power plant's Spent Fuel Storage Pool and Spent Fuel Storage Pool Cooling System to filter and cool contaminated air and steam vapor released from within a Reactor Containment Vessel/Building preventing vessel overpressure and radioactive release.

Claims

1. A nuclear power generating facility having a containment for housing a nuclear reactor and for confining radiation leaked from the nuclear reactor, the containment having a ventilation outlet for providing a controlled release to the environment surrounding the containment, for an atmospheric pressure buildup within the containment in the event the pressure of an atmospheric effluent within the containment is built up to a level that exceeded a preselected value, and the nuclear power generating facility also having, outside the containment, an associated spent fuel storage water pool, including a filter system for filtering contaminants released from or on route to the ventilation outlet, the filter system comprising: a dedicated piping system connected between an interior of the containment or the ventilation outlet and the spent fuel storage water pool for fluidly communicating any atmospheric effluent to be released from inside of the containment through the spent fuel storage water pool; one or more valves connected to the dedicated piping system for controlling the release of the atmospheric effluent to be released; a chemical injection system configured to release a chemical into the spent fuel storage water pool to facilitate a reaction with the atmospheric effluent to be released to substantially neuter any deleterious environmental impact of the atmospheric effluent to be released; and a control system connected to one or more of the chemical injection systems and/or the one or more of the valves and configured to control the release of the chemical and/or the release of the atmospheric effluent.

2. The nuclear power generating facility of claim 1 wherein the dedicated piping system includes a check valve configured to prevent spent fuel pool water from being drawn into the containment.

3. The nuclear power generating facility of claim 1 wherein the control system includes a manually actuated, remotely operated valve in the dedicated piping system, the valve being configured to isolate the atmospheric effluent from the spent fuel water pool under normal operating conditions, unless actuated.

4. The nuclear power generating facility of claim 3 wherein, the manually actuated, remote operated valve is configured in the dedicated piping system to be in parallel with a passively operated valve structured to release the atmospheric effluent to the spent fuel water pool if a pressure is sensed within the containment in excess of a given pressure.

5. The nuclear power generating facility of claim 1 wherein the dedicated piping system has an outlet in a lower portion of the spent fuel water pool that releases the atmospheric effluent to the spent fuel water pool through a sparger.

6. The nuclear power generating facility of claim 5 wherein the chemical injection system releases the chemical into the spent fuel water pool through a chemical injection header that is supported just above the sparger within the spent fuel storage water pool.

7. The nuclear power generating facility of claim 6 wherein the chemical injection header and the sparger are supported within the spent fuel storage water pool at an elevation below a level that is used to transfer fuel into and out of the spent fuel storage water pool.

8. A method of releasing an atmospheric effluent within a nuclear containment to an atmosphere surrounding the nuclear containment, the containment having an associated spent fuel pool outside the containment, the method comprising the steps of: sensing a pressure buildup within the containment; routing a portion of the atmospheric effluent through the spent fuel pool when a pressure buildup within the nuclear containment reaches a preselected value; and releasing a chemical into the spent fuel pool to facilitate a reaction with the effluent to be released to substantially neuter any deleterious environmental impact of the effluent to be released.

9. The method of claim 8 including the step of performing the routing step and the releasing step at approximately the same time.

10. The method of claim 8 wherein the routing step includes the step of introducing the atmospheric effluent into water in the spent fuel pool through a sparger supported near or at a bottom of the spent fuel pool.

11. The method of claim 10 wherein the releasing step releases the chemical into water within the spent fuel pool at an elevation near the bottom of the spent fuel pool just above the sparger.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A further understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:

[0010] FIG. 1 is a schematic view of a reactor containment building spent fuel pool filter vent in accordance with this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0011] This invention involves an application specific design of piping, valves, control logic and a chemical injection system to effectively employ the concepts of a wet filtered vent design, such as the one described in U.S. Pat. No. 9,502,144, without the addition of a wet filter vent filtration tank. One embodiment of this invention is illustrated in FIG. 1, which shows a schematic representation of a portion of a nuclear containment and adjacent spent fuel pool. This invention uses ventilation piping 10 that directs a pressure relief discharge from the containment vessel 12 into the planes existing spent fuel pool 14 through an engineered sparger design (or existing spent fuel pool cooling system sparger) 16. Isolation of the ventilation piping is achieved via conventional, remotely operated valve(s) 18, controlled to open by manual actuation by the plant operator. An alternate bypass system, with passive pressure relief valve 20, is available in the event of an operator error or mechanical failure of the isolation valve(s) 18. The bypass system automatically opens the valve 20, which is a passive pressure relief device, if a preselected pressure is sensed in the containment.

[0012] The contaminated aerosol release will be filtered via the spent fuel pool inventory, which will be treated with conventional wet filtration chemistry control via a passive chemical injection system 22 for gas (e.g., iodine, cesium, xenon) and fission product particulates removal. The chemicals will be released into the pool inventory simultaneous with the ventilation release to the pool. (i.e., opening of the ventilation isolation valves 18 or 20) via a controlled opening of the chemical injection system isolation valve 24. The chemicals will be injected directly above the sparger outlets 16 via a chemical injection header 26. Preferably, the chemical injection header and the sparger are supported in the spent fuel pool at an elevation, preferably, as low as possible in the pool and below the operating level necessary for fuel transfer into and out of the pool. The chemical injection header 26 is, preferably, positioned just above and over the sparger 16.

[0013] The consequential fission product decay heat energy released to the pool will be removed by the current spent fuel pool cooling system. Aerosol release from the spent fuel pool surface will be vented from the spent fuel building via normal or special supplemental, if necessary, spent fuel pool ventilation systems. Liquid swell in the spent fuel pool will not be sufficient to displace excessive pool inventory such that acceptable spent fuel bundle submergence remains for shielding the spent fuel following closure of the vent isolation valves. Check valve(s) (passive dampers) 28 in the ventilation piping will prevent draw of pool inventory into containment during any containment vessel vacuum; similarly, a passive vacuum breaker 32 will prevent the containment vessel from exceeding a maximum vacuum limit.

[0014] While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. An example could be to avoid installation of a unique containment vessel penetration, an alternate embodiment could incorporate the device into the existing fuel transfer tube 30. Accordingly, the particular embodiments disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.