What is the Station Vent used for?

[MastersBound]

Typically on PWR's (not sure about BWR's) there is always a rather large stack that is attached to the side outside of the Reactor Bldg. It is known as the station vent. Can anyone tell me what this is used for and how it works? Also, can anyone tell me if this is the same as what is know as the "off-gas vent"?

[MastersBound]

Attached is a picture of the station vent I was inquiring about. Not sure what plant this is but it looks like a PWR.

[QuantumPion]

I am thinking it may be the main steam dump valve but those should be on the main steam headers, and on the plant's I've seen they did not have vertical pipes like that. Based on its size that would be my guess though.

[MastersBound]

Definitely not Main Steam. The Main Steam relief valves (around 10) are in the same area but do not use the Station Vent. I'm doing more research as we speak but apparently it is used for several different scenarios. It is predominantly used to purge/vent the Auxiliary bldg (not reactor bldg) or the annulus in case of an accident or leak or other scenarios. The aux. bldg remains at negative pressure for this particular reason. All exist "gas" goes through charcoal filters, etc and is rad monitored.

Hopefully I'll have more specifics as the day unfolds but would still like other forum members comments if can provide additional information.

[jim hardy]

it's the exhaust stack for plant ventilation systems.
So at times modest amounts of activity will go out through it.
Ours was instrumented and high radiation shuts down vent system bottling everything up.

remember, we plant workers and our families live downwind too.

old jim