
@skibboy yeah freedom !!
by elainekirk 5/22/2011 1:32:16 AM

YEP... a fission
by dean 5/22/2011 1:32:25 AM

ty radioguy
by dean 5/22/2011 1:36:13 AM

Anybody else notice that chubu are actually voluntarily putting information into the public domain? what a contrast to tepco
by elainekirk 5/22/2011 1:40:09 AM

It now seems that the physical integrity of RPV penetrations larger than instrumentation lines were compromised for a time on each Unit, and TEPCO had more than enough evidence to tell us upon discovery of the turbine basement waters. For Unit #3, this may have included one or more of the CRDMs through the bottom of the RPV. Speculation now exists that some of the fully melted core (corium) from Unit #3 fuel cell may have broken through the CRDM housing (or housings) and fell to the concrete floor beneath. The base mat below the RPV is ~ 10 feet thick, made of high-density steel-reinforced concrete. Even a full corium breach to the floor wouldn't get more than a few inches into the base mat before cooling and solidifying. Regardless, the leaked corium would have cooled and solidified almost immediately upon contact with the floor.
by dean 5/22/2011 1:40:33 AM

haven't seen that elaine
I think we are being pretty well informed of hamaoka's problems
by dean edited by elainekirk 5/22/2011 1:40:55 AM

JAIF reports operators of Unit #1 manually shut off the automatically-initiated flow of cooling water to the core 10 minutes after the earthquake, because of an unexpected pressure drop inside the RPV. Cooling water flow remained shut off for three hours. No wonder Unit #1 melted first. Decay heat production is massive for the first hour after reactor fissioning ceases (SCRAM), and remains high for several hours after that. This is a gross example of operator error. Never, ever should emergency cooling water flow be stopped...not for any reason!
by dean 5/22/2011 1:42:17 AM

@dean According to the AREVA report, cooling in the isolation condenser in unit 1 stopped at 16:36 on March 11, less than an hour after the backup diesel generators had failed. By contrast, the RCIC pump in unit 3 continued until 02:44 on March 13, about 35 hours after loss of backup power. In unit 2 the RCIC survived until 13:25 on March 14, some 46 hours after the accident.
by elainekirk 5/22/2011 1:49:57 AM

I would say that and RV's
by dean 5/22/2011 1:50:12 AM

I believe there were a series of things happened as a result of the EQ and subsequent loss of off site power as well as operator intervention to shut off the emergency core cooling that resulted in inability to maintain proper make up to the RVP. reports are that the electrical grid changes in voltage surges, frequency etc can have affects on the power for the control valves and systems in the reactor.
by dean 5/22/2011 1:55:31 AM

operation of the RCIC on steam requires the reactor to be continued to produce enough steam to drive the RCIC system to provide adequate cooling.. the pressure increase from right after scram I think was stopped but automatic action of the safety relieve valves which took the pressure down and subequently the RPV level
by dean 5/22/2011 1:58:05 AM

yes skibboy
by dean 5/22/2011 1:58:16 AM

I have heard some reports where they questioned if all the control rods made it down in unit 1..
by dean 5/22/2011 2:03:32 AM

well.. it's my rest time.. ty all ..PEACE to all
by dean 5/22/2011 2:03:46 AM

My bedtime too g'night all:)
by elainekirk 5/22/2011 2:04:56 AM