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  • Originally posted by Tarek Morgen View Post
    The same (and highest) Level on the scale.
    So far Japan is admitting to 1/10 the release of radiation as occured in the Ukraine but is admitting the eventual totals might well surpass it. Becuase of the sheer compactness of Japan, population density and realestate value the total cost in terms of human health, money and lives disrupted is already likely far greater. especuially given the news that Japan is begining a new round of evacuations of areas already exposed to dangerous levels of radiation weeks after this was known.

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    • Greetings. Long time reader of WAB, never posted before. I have been following this thread fairly closesly. I do have a question that hopefully somone can answer. Aparently, the Fukushima reactors were susposed to have an emergency cooling system that used steam from the reactors to power pumps, to keep water circulating through. This system some how failed, but the details are vague. Does this system need sone type of battery power? Or was there a mechanical failure that caused this system to stop cooling.

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      • Apparently the diesel generators that would power the coolant pumps indefinitely (given fuel) were flooded. Makes one wonder why they were positioned low, rather than on flood and earthquake-proof scaffolding.

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        • Originally posted by Fastam View Post
          Greetings. Long time reader of WAB, never posted before. I have been following this thread fairly closely. I do have a question that hopefully someone can answer. Apparently, the Fukushima reactors were supposed to have an emergency cooling system that used steam from the reactors to power pumps, to keep water circulating through. This system some how failed, but the details are vague. Does this system need some type of battery power? Or was there a mechanical failure that caused this system to stop cooling.
          That is a good question, it sounds like the old reactor design didn't consider the diesels being off line (as they were due to the flood). It would not have been that much of a stretch to wire things so the turbine generator could power its own pumps, with a battery fail over for start up. But it appears that this was safety mechanism was either not set up or not maintained - given the stuck vent valves and over stuffed pools, my guess would be it wasn't maintained in operational condition at this troubled site. The operators of this site should never be in charge of another reactor IMO. Old reactors (needing to be decomm'd years ago), bad operators (not maintaining safety systems or following spent fuel regulations), and a natural disaster added up to this mess, with either one of these first two factors removed they would probably have another Onagawa power plant situation (a non-event).

          It reminds me of Homer Simpson - Nuclear Safety Engineer.
          Last edited by USSWisconsin; 15 Apr 11,, 14:41.
          sigpic"If your plan is for one year, plant rice. If your plan is for ten years, plant trees.
          If your plan is for one hundred years, educate children."

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          • Originally posted by Chogy View Post
            Apparently the diesel generators that would power the coolant pumps indefinitely (given fuel) were flooded. Makes one wonder why they were positioned low, rather than on flood and earthquake-proof scaffolding.
            They were built with the 'I'll never happen to me ' attitude. They were built to withstand a magnitude they had been accustomed to rather than the worst that nature could throw at them.

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            • Originally posted by USSWisconsin View Post
              That is a good question, it sounds like the old reactor design didn't consider the diesels being off line (as they were due to the flood). It would not have been that much of a stretch to wire things so the turbine generator could power its own pumps, with a battery fail over for start up. But it appears that this was safety mechanism was either not set up or not maintained - given the stuck vent valves and over stuffed pools, my guess would be it wasn't maintained in operational condition at this troubled site. The operators of this site should never be in charge of another reactor IMO. Old reactors (needing to be decomm'd years ago), bad operators (not maintaining safety systems or following spent fuel regulations), and a natural disaster added up to this mess, with either one of these first two factors removed they would probably have another Onagawa power plant situation (a non-event).

              It reminds me of Homer Simpson - Nuclear Safety Engineer.
              This is the system I am refering to.

              Also; Do you have any outside links you can point me to that show that the reactor vents valves were stuck? Or is that your informed opinion?

              The Reactor Core Isolation Cooling System is not a safety-related system proper, but is included because it can help cool the reactor in the event of a contingency, and it has additional functionality in advanced versions of the BWR.

              RCIC is designed to remove the residual heat of the fuel from the reactor once it has been shut down. It injects approximately 2,000 L/min (600 gpm) into the reactor core for this purpose, at high pressure. It also takes less time to start than the HPCI system, approximately 5 seconds from an initiating signal.

              The RCIC system is operable with no electric power other than battery power. During a station blackout (where all off-site power is lost and the diesel generators fail) the RCIC is capable of providing decay heat removal by itself.

              Versioning note: RCIC and HPCF are integrated in ABWRs and (E)SBWRs, with HPCF representing the high-capacity mode of RCIC. In the (E)SBWR series of reactors, there is an additional contingency residual heat removal capability for RCIC, the Isolation Condenser System (IC); in the (E)SBWR, there are several separate trains of heat exchangers located above the RPV in deep pools of water within the reactor building but outside and above the primary containment. In the event of a contingency, the decay heat of the reactor will boil water to steam within the RPV. The RPS will activate several valves connecting the RPV to the IC system; the steam from the RPV decay heat will flow into the heat exchangers (called Isolation Condensers) and be condensed and cooled back to liquid. The water will then return to the RPV through the force of gravity.
              Boiling water reactor safety systems - Wikipedia, the free encyclopedia
              Last edited by Fastam; 15 Apr 11,, 23:23.

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              • Originally posted by USSWisconsin View Post
                It would not have been that much of a stretch to wire things so the turbine generator could power its own pumps,
                Those turbones are MW class and the pumps need KW, with the grids down, where is that power going?

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                • Originally posted by zraver View Post
                  Those turbones are MW class and the pumps need KW, with the grids down, where is that power going?
                  From what I understand these are suposed to be turbines seperate from the electrical power generating ones. Their purpose is solely to mechanicaly power emergency cooling pumps, yet these failed some how. One source I have found says it was due to battery power failing. I am not sure why that would be an issue.

                  EDIT: Found this interesting.

                  Once the earthquake hit it appeared that the plant was taken offline (possibly automatically) immediately. Because the plant was probably operating at near full power for a sufficient length of time as most electric power generating reactors are, decay heat inside the core would have been considerable. Even after shutdown the core would produce a significant fraction of its full power for a number of hours. Under normal circumstances the heat from this power would be transferred to coolant driven by electric feedwater pumps. The earthquake knocked all the plants offline at the station and disrupted commercial power coming in, rendering this option unusable. The second backup would be on-site diesel generators designed to come online and power emergency systems indefinitely. It appears that the tsunami disabled the diesel generators as well. The third backup was to use latent heat from the reactor itself in order to turn a steam driven feedwater pump and pump coolant into the core. There is not a great deal of information about the timeline of events within the control room at Fukushima-1, but it may have been the case that operators chose not to use this option or turned to it too late and found the pressure inside the core exceeded the output pressure of the steam driven pump. Their immediate concern also may not have been cooling but simply keeping the core covered, in which case they may have decided against the release of steam early on in the disaster. I don’t wish to engage in monday morning quarterbacking; the operators must have been under intense pressure. The final backup system was a battery backup for the feedwater pumps. Even without an increased demand for power from higher core pressure the batteries were likely only designed to operate for a few hours.
                  Last edited by Fastam; 16 Apr 11,, 00:09.

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                  • I get the feeling that a lot of systems at Fukishima I (reactors 1,2,3) were not properly maintained.
                    sigpic"If your plan is for one year, plant rice. If your plan is for ten years, plant trees.
                    If your plan is for one hundred years, educate children."

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                    • This sounds good:

                      Experts Foresee No Detectable Health Impact from Fukushima Radiation - NYTimes.com

                      Hopefully it puts runs on the board for Nuclear power.

                      China is building 26 but the rest of the world needs to start. If we like our way of life, and carbon is bad, then it's the only way.

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                      • What have those people in Fukushima did wrong?

                        Fukushima Earthquake 2013: Quake Reported Near Damaged Nuclear Plant


                        The Weather Channel ✔ @weatherchannel

                        The 1:25pm EDT (2:25am Fri Japan time) #earthquake was centered on land; therefore, no #tsunami threat.
                        7:42 PM - 19 Sep 2013

                        Hope everything will end good, tho not very optimistic.
                        No such thing as a good tax - Churchill

                        To make mistakes is human. To blame someone else for your mistake, is strategic.

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                        • Watched the news in TV...very sad to hear

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