Reply #30: Reactor can vent either into containment or into open space. [View All]

[Statistical]

Containment is generally preferred because is means 0 release into environment and the anti-nukker freak about any release (even if it is less exposure than one gets by taking a long distance flight or living in a brick house).

Reactors have hydrogen igniter. They ignite the hydrogen to create a controller burn inside containment. This prevents the hydrogen from building up into a concentration that leads to an explosion.

So why did the explosion occur. This is something the industry will be looking at closely. One possibility is the igniter failed during the disaster. The operators may have been venting into containment not realizing the H2 was reaching dangerous levels.

Containment building in a BWR is roughly 35x larger than the RPV (reactor pressure vessel). By combined gas law we know rise in volume equals drop in pressure. So using containment as a larger "bucket" also a significant reduction in pressure.