Further study of the control room records which became available last week reveals answers to additional questions…
- Why did they use sea water to cool the reactors when there were concerns that it might make the chain reaction restart (recriticality)? Could the sea water have been part of the reason for the explosions?There was enough fresh water stored at each unit to supply emergency flow to the RPVs for about 24 hours. Typically, the recycling of water through the condensate and feedwater systems maintain RPV level, with stored pure water used to fill the system for maintenance and refueling periods (outage). The stored supply is more than needed to fill the RPVs for an outage. Unit #1 had about 80 tons of replenishment water available in the plant’s tanks. When this volume ran out about 8 hours after the tsunami, fire engines pumped water into the plant from other fresh water tanks at the power complex. At 2:53 pm on March 12, all fresh water supplies ran out. At 2:54 pm, the plant manager ordered preparations to begin using sea water from the outer drainage trenches, which had been filled by the tsunami. As we have mentioned in earlier updates, keeping the fuel cells inside the RPVs replenished with cooling water is of critical importance. When fresh water supplies ran out, the plant operating staff had no choice but to use sea water.
The concerns of sea water somehow restarting the fission chain reaction inside the fuel cells existed within the Prime Minister’s staff, some officials at NISA, and some officials at TEPCO’s Tokyo home office. There is nothing in or about sea water that could cause recriticality in a fully shut down reactor fuel cell. The Plant Manager knew the off-site concerns of recriticality were unfounded, so he correctly started sea water injection, even after he was told to stop the injections with units 2 and 3. As it turns out, plant operators were ready to inject sea water into the unit #1 RPV using the high pressure Standby Liquid Control (SLC) system, powered by portable diesel generators, at 3:36 pm, but never actually began the process. A few seconds after the SLC system entry in the records, the hydrogen explosion occurred which damaged the makeshift electric supply cable severely enough to make immediate sea water injection impossible. At 7pm that evening, sea water injection began using fire pumps and internal steam-driven pumps. At 8:45pm, boric acid was added to the sea water injection to further reduce the possibility of recriticality.
Sea water injection had nothing to do with the hydrogen explosions at units 1, 3 & 4.
- Wait a minute…you reported that fire trucks didn’t arrive at Fukushima until March 17. All news media and government reports say there were no fire trucks or portable electrical generators at the plant site before the fire companies arrived. Were the fire trucks and portable generators in the control room reports of March 12 real, or not?The report from TEPCO, the government, and the Press about fire trucks and portable generators never mentioned the vehicles already available to the power complex. It seems three fire trucks were on site all-along. TEPCO had some portable generators located a few kilometers away and others were sent to Fukushima by the neighboring Tohoku Company. As it turns out, Japanese Accident Management measures (AM) taken after the 2007 Niigataken Chuetsu-oki Earthquake were implemented by TEPCO for Fukushima Daiichi, which included having fire trucks and portable power supplies available on or near the plant site, and additional fresh water fire protection storage tanks installed. It seems these facts were not reported by TEPCO or NISA after the tsunami hit. Did they assume everyone already knew? In a nuclear emergency with the whole world watching, assume nothing!
The nearby power trucks arrived soon after midnight, early in the morning of March 12. The closest they could get to the only operable plant power panel common to both unit #1 & 2, was about 200 meters from outside the turbine building. A contractor building on site had some heavy-duty portable cabling long enough to connect the power trucks to the distribution panel. The had to literally “blow open” some of the tightly closed doors leading into the control panel room between the reactor and turbine buildings in total darkness. Using mechanized cable-laying equipment would have taken more than a day, but a team of plant operators did it by hand in a few hours. The cabling was laid, connected between the power truck and panel, then energized just 6 minutes before unit #1’s hydrogen explosion. High-velocity debris damaged the portable cable beyond repair. The operator’s strenuous efforts to get units #1 & 2 re-energized were in vain.
In summation, the plant had some emergency vehicles available soon after the blackout. Why wasn’t the availability of these portable power trucks and fire trucks told to the world?
- Recently, it was announced that RPV water level instruments were giving false readings. How did the operators know what the water levels were on the three RPVs the first few days of the accident?There are at least two water level instruments on each RPV. By comparing the readings between the instruments water level inside the RPV can be read with high confidence. Once the cores were uncovered, the terrific heat inside and around the RPVs must have caused the instruments to be damaged. After the cores eventually cooled down, water levels were indicated to be constant, but did not change regardless of the amount of water being injected. This indicated faulty water level instrument readings.
- It has been reported that the fire pumps could not operate at a high enough pressure to inject into the pressure vessels. How did they get water injected?Three fire trucks literally ferried water to the reactor cooling systems from fire suppression system supply tanks until the supply ran out, then subsequently ferried sea water from the drainage trenches. The pumps were sufficient to feed water to the inlets of the SLC pumps in unit #1, which are capable of pumping into very high pressure environments. The report says the SLC pumps were powered from a portable supply truck, but the date and time the power truck began sending electricity to SLC is not in the available control room records.
- Japanese news media reported there was only one emergency procedure manual at Fukushima Daiichi, and it was not located in any of the control rooms. Does the operator’s record say anything about this?Yes. The unit #1 record mentions the existence of an emergency procedure manual at the Power Station Emergency Response building (PSER). Staff was sent there in order to learn how to vent pressure from the Primary Containment (Drywell) and Suppression Chamber. They next took the manual to one of the site Administration buildings to get blueprints in order to find where the hand-operated venting equipment was located. On the blueprints, it was shown that the manual operation of one valve on the instrument tubing would open the vent valve. The manual and drawings arrived in the control room shortly after midnight, early in the morning of March 12. If venting would have begun soon thereafter, it is possible that the unit #1 hydrogen explosion could have been averted, as well as the unit 3&4 explosions.
Not having an emergency procedure manual and a detailed set of plant system blueprints stored in each control room is dumbfounding. Because of delayed preparations to vent, combined with the sociopolitical delay of confirming public evacuation, radiation levels in the area of the manual operation valve was so high that no one was allowed to stay in the area long enough to ensure the valve was fully opened. Lack of ability to communicate between the plant and the operators in the plant caused further delays once it was decided to actually start venting. Unit #1’s records say they eventually resorted to using pneumatic pressure inside the instrumentation system to facilitate opening the vent valve. The pneumatic pressure rapidly decreased, so the vent valve only partially opened.
Now, back to the current situation in Japan…
- Yesterday, the on-again/off-again waste water decontamination system was shut down for 12 hours to repair leaking tubes carrying decontamination liquids to the system. The leaks did not contain radioactive materials. The system is now back in full operation.
- A new scandal has erupted concerning the Genkai restart issue. In June, the Kyushu electric company and NISA held a widely-broadcast meeting to say Genkai units #2&3 are safe to restart. As it turns out, Kyushu Electric asked at least 50 of their employees living near the power complex to send in supportive emails. This accounted for about 20% of the supportive emails received. Knowledge of this has spread like wildfire among all Japanese news media outlets. The investigation is ongoing and expected to find even more alleged tampering. On one hand, it sounds like an unethical attempt to manipulate public opinion. On the other hand, the Kyushu employees were local residents and had a right to speak their piece. Further, is this not the same sort of tactic used by nuclear nay-saying groups to manipulate public opinion?
- The Prefectural governors in Japan now seem to be in support of the Prime Minister’s desire to delay restart of idled nuclear plants until the new, ambiguous “stress test” has been run. It seems those that pass will be allowed to restart, and those which fail must make appropriate upgrades before they will be allowed to restart. The governors feel that waiting until the tests are run will improve public opinion relative to restarts. All admit the current power shortage situation in Japan will continue through the summer, at least.
- NHK World reports that Fukui Prefectural officials want the stress tests run, but also demand to know the full extent of damage at Fukushima Daiichi and whether or not the age of the four damaged plants had anything to do with the nuclear emergency, before they make restart decisions. Until they get answers they will not support restart of the Fukui Prefecture reactors. Fukui has the most reactor plants of any Prefecture in Japan.
- Although it should come as no surprise, the ash from some of the waste incinerators in Fukushima-neighboring Chiba Prefecture has high levels of radioactive cesium. This is making quite a news media stir. The trace-to-low concentrations of cesium isotopes in the debris being incinerated not flammable. Thus, we have a natural concentration effect when all other combustibles are burned and the cesium isotopes remain. The incinerator operators want to know what to do with the significantly radioactive ash. The government must decide on disposal or the available storage space at each incinerator site will be filled.