TheCultofAbeLincoln
12th March 2011, 14:08
"We’ve confirmed that the reactor container was not damaged. The explosion didn’t occur inside the reactor container. As such there was no large amount of radiation leakage outside," Japan’s Chief Cabinet Secretary Yukio Edano said in a news conference Saturday evening. "At this point, there has been no major change to the level of radiation leakage outside, so we’d like everyone to respond calmly."
So, the quake hit, Rx scrammed like it was supposed to. Other commercal power sources are gone due to the quake, and the diesel generators are subsequently destroyed by a tsunami. Talk about a crappy situation.
After a scram, approximately 7% heat load of the Rx is going to be needed to be cooled after all rods are on the bottom of the core, assuming the Japanese use the basic Rx design of using either hafnium or cadmium control rods to limit reactivity. With no flow across the core, the cooling water heats up to an equilibrium temperature and is no longer a heat sink, instead the cooling water's temperature rises, causing it to expand and its density does down, until you have the explosion. However, it's clear that the Japanese use some type of Rx venting system to relieve that pressure.
What I do not understand is, coming from training solely on Naval Rx's, why is there no form of emergency circulation flow? Our Rx's have a path of natural recirculation, created by thermal driving head, to relieve decay heat in this exact scenario. Is there no system like this on civilian plants?
So, the quake hit, Rx scrammed like it was supposed to. Other commercal power sources are gone due to the quake, and the diesel generators are subsequently destroyed by a tsunami. Talk about a crappy situation.
After a scram, approximately 7% heat load of the Rx is going to be needed to be cooled after all rods are on the bottom of the core, assuming the Japanese use the basic Rx design of using either hafnium or cadmium control rods to limit reactivity. With no flow across the core, the cooling water heats up to an equilibrium temperature and is no longer a heat sink, instead the cooling water's temperature rises, causing it to expand and its density does down, until you have the explosion. However, it's clear that the Japanese use some type of Rx venting system to relieve that pressure.
What I do not understand is, coming from training solely on Naval Rx's, why is there no form of emergency circulation flow? Our Rx's have a path of natural recirculation, created by thermal driving head, to relieve decay heat in this exact scenario. Is there no system like this on civilian plants?