The Deliberate Forgetting of the ECCS independent, Integral “Ultimate Heatsink”

The World Nuclear Organisation describes the claimed role of “ultimate heatsink” desctuction in the chain to reactor disaster, as follows “….Then 41 minutes later the first tsunami wave hit, followed by a second 8 minutes later. These submerged and damaged the seawater pumps for both the main condenser circuits and the auxiliary cooling circuits, notably the Residual Heat Removal (RHR) cooling system. They also drowned the diesel generators and inundated the electrical switchgear and batteries, all located in the basements of the turbine buildings (the one surviving air-cooled generator was serving units 5 & 6). So there was a station blackout, and the reactors were isolated from their ultimate heat sink. The tsunamis also damaged and obstructed roads, making outside access difficult.” (Source: World Nuclear World Nuclear Association, “Fukushima Accident 2011,

The RHR cooling equipment is located some distance from the reactors. The RHR seawater pumps being next to the sea. The ECCS did not use any of the flooded cooling system equipment nor should have needed any of the flooded and damaged generating equipment. At the time the reactors were designed and built, it was claimed they complied with all US regulations. And that included the requirement for the ECCS to operate independently for as long has decay heat removal was needed to ensure no hydrogen was generated in explosive amounts and that core overheat did not occur. The ECCS has to do this by self contained inviolate
Further, the ECCS has it’s own integral “ultimate heatsink”.

“Ultimate” does not mean “only” or “sole”. Where there are independent cooling circuits, there are independent heatsinks. In relation to each circuit, each has its own heatsink and for each one, that heatsink is “ultimate” because without it, it would not be a cooling circuit.

Fairewinds Energy Education at further explains events in terms of “ultimate heatsink”. All educational and important information. However, the explanation of events in terms of a single “ultimate heatsink” set of hardware which were destroyed by the tsunamis is inadequate. The independent ECCS “ultimate heatsink” was not touched by the tsunamis.

Arnie Gundersen: “If the water pump fails, your engine dies. Well, that is really what happened at Fukushima Daiichi. Those pumps along the water provide cooling water to the diesels, just like the pump on the front of your engine on your car. Without those pumps operating, the diesels were doomed to fail anyway. It does not matter if those diesels were 100 feet in the air. The pumps along the water were destroyed. And that is the real root cause of the accident at Fukushima Daiichi. We call that the loss of the ultimate heat sink. And the keyword there is ultimate. You need the ocean to pull the water out of the nuclear reactor to keep it cool. But that same water has to cool the diesels to make that happen. The diesels would not have worked even if they had not been flooded. Now this problem that we call the loss of the ultimate heat sink, did not just happen at Fukushima Daiichi I, II, III, and IV. All 6 reactors at the Fukushima Daiichi site experienced it, but also at the Fukushima Daini site, the Onagawa site, and the Tokai site. Between those 4 sites there are 14 nuclear reactors. They had 37 diesels. 9 of them failed because of the tsunami. Those are the ones at Fukushima Daiichi I, II, III and IV. But 15 others failed too. Mainstream media is not talking about that and the nuclear industry is not talking about that either. The diesels were not flooded. What happened was the pumps along the ocean were destroyed, not just for Fukushima Daiichi I, II, III, and IV, but for every one of those sites at least one diesel was knocked out because it could not be cooled.”

It’s all reasonable and important information, except for the fact that when the primary cooling circuits are destroyed, the ECCS is automatically invoked. And the ECCS has its own heatsink, the water never leaves the pressure vessel/torus circuit in the ECCS loops. If the ECCS is to function at all, it must have its own heatsink. And it does. The ECCS has its own dedicated integrated steam line, steam turbine and turbine driven pumps. The only thing it does not have which is ECCS system powered is ECCS powered ECCS pipe valves. This is a fundamental design failure and a failure of regulation.

And at Fukushima Diiachi, multiple authorities, including the Japanese Diet investigating committees attest to the fact that the ECCS Emergency Core Cooling Systems were running after starting automatically immediately after the earthquake. And we know concretely that the ECCS specific steam turbines inside the reactor buildings and directly connected to the reactors were spinning, the coolant pumps located next to each pressure vessel were pumping. From the NRC BWR reactor manual we know that GE Mk1 – Mk3 reactors all have ECCS cooling circuits WHICH DO NOT LEAVE THE REACTOR BUILDINGS. We know the fatal weakness was the electrically operated ECCS valve solenoids. When the batteries which powered these valves went flat, the ECCS coolant flow ceased even though the steam turbine and the ECCS pumps were perfectly fine and operating.

Now, if the ECCS cooling circuit does not leave the vicinity of the reactors and reactor buildings what is the “ultimate heatsink” for the ECCS?

heatsink The “ultimate heatsink” for the ECCS of each Mk1 reactor is in plain site in this picture. The reactors were not damaged by the sea. Neither were their ECCS heatsinks. From the time of the earthquake on, the ECCS cooling systems were running. This is admitted in the record by three sources, World Nuclear, Japanese Diet, TEPCO, NHK. TEPCO itself admits the ECCS of reactor one was manually turned off and then on again. The reason given for turning off the ECCS was that the reactor temperature fell too low. And even when all generating equipment was flooded and when all primary coolant “ultimate heatsinks” were destroyed, the independent self contained steam powered ECCS pumps kept the cores below destructive temperatures for some days.By the 14 March 2011 all ECCS had ceased. By that time the batteries powering the electrically operated valves had all gone flat. Now, obviously, had those batteries not gone flat the disaster would not have occurred, either totally or in the manner that it did. Even if the quake caused pipe breakage, the ECCS was supposed to cope.
But in terms of the ECCS “utlimate heatsink”, well, it wasnt not destroyed by the sea.

The heatsink for this cooling circuit cannot be the primary circuit heat exchangers that are located by the sea.

The coolant loop – the only coolant movement – in the ECCS is from pressure vessel to torus and back again. The purpose of this movement is to move heat from core to torus. The change in state of water from liquid to vapor and back again is important in the “heat pump” action of the ECCS. Which one is the “Ultimate heatsink” for the ECCS? It’s the Torus.

The big myth in the media narrative is that the ECCS did not matter. Doesn’t rate a mention. That is crap. It did matter and it mattered so much that the issue of ECCS consumed the AEC from 1967 on, the issue coming to its head in around the mid 1970s. At that time the AEC held public hearings, dismissed objections and said these are the rules, the ECCS is fine, they will work and melt down fears and containment fears are, “we believe” unfounded by the facts.

Now I think the Fukushima Diiachi disaster was going to happen on the basis of design and regulation failures in place since 1967. However, had the AEC and US government listened or given credence to the fears expressed by independent thinkers, scientists and members of the public in the period to 1975 and had the Japanese government listened as well – they, sadly, had bought the product in question – then March 2011 in Japan would still have been an awful, tragic month. The country though by now would be recovering. As it is, TEPCO is still desperately using duct tape in an effort to stop the leaks.

And so is the information arm of nuclear industry.

Here again is the NRC technical manual illustration of one part of the ECCS circuit of the Mk1 – Mk 3 ECCS cooling loop. Goes in the top, turns to steam, absorbing heat, is driven down to the water in the bottom of the picture. The steam turns to water, releasing heat which heats up the volume. The volume is a circular metal housing which transfers its heat to the air. It is a circular volume is the heatsink and it is called the Torus:

NRC Technical Manual BWR Mk1 – Mk3, one of the two types of ECCS circuits in the Fukushima Diiachi reactors. Each reactor has multiple ECCS circuits of both types.

Now in relation to the ECCS cooling systems, the torus was fine as its “ultimate heatsink”.

But when the batteries went flat and shut off the valves holding open the ECCS coolant pipes, the cores overheated. And the Torus is the weakest part of the containment.

Great radiator for the ECCS, its built right in. Shit containment component though.

We have to understand that the ECCS ultimate heatsink, the torus, never had to cope with reactor power up heat, as a heatsink. That was the job of the primary coolant loops. The ECCS heatsink had to cope with decay heat alone, as a heat sink. And it did that bit OK. Until the ECCS failed. Because it never did comply with the rules.

The terminology “ultimate heatsink” is deliberately misleading in systems which have multiple cooling systems and multiple heatsinks.

The neglect to specify and describe the role of the torus as the ECCS heatsink (radiator) is highly flawed and suspect in my opinion.

So long as the ECCS coolant flow works, so long as air surrounds the outside of the Torus, the torus will act as a radiator for heat dumped in the suppression pool by the ECCS systems via their coolant circuits.

The reactors did not blew up and meltdown because the sea destroyed the primary circuit equipment and pumps. They blew and melted down because the ECCS solenoid valves lost power because the batteries went flat whereas those valves did not, and never did meet, the requirement that they be powered independently and in an inviolate fashion for as long as decay heat had to be removed from the core.

If the pumps kept working in the ECCS, and they did, why exclude the solenoid valves from this same intrinsic and inviolate power source? It breaches the design requirements and has done since the reactors were first sold to Japan by the United States.

It is extremely depressing to see these things.

Arnie, yea it is true that had any juice from any source been able to keep those solenoids powered, the disaster would not have occurred. However, the big foreseen failure was the failure to make those solenoids comply with the requirements for ECCS. Para 5 of the ECCS acceptance criteria. To operate so long as there is decay heat to remove from the core. How could the industry not see the danger over all those years?

The ultimate heatsink for the ECCS is the air/metal heat exchange between the torus and the atmosphere.

That the ECCS solenoids did not comply with mandates is a massive decades long piece of negligence the industry media narrative deliberately avoids invoking. In my opinion.

It is really important to remember the promises made by nuclear industry and regulators when these reactors were designed, approved, built and discussed by the public in the period since the 1960s. History shows a clear trail of suppression, denial and false assurances. As well as a profound failure in duty. Though the ECCS could have prevented the disaster, it did not because it did not in fact comply with relevant laws and both designing corporations and regulators are either too dumb to see or wilfully neglectful in my opinon, as far as I can see.

See also:

All a nuclear reactor core has to do is generate sufficient heat to boil water. Left to its own devices, a core temperature sufficient to melt uranium and plutonium is in fact reached. This excess heat characteristic, so in excess of the temperature actually needed, renders to the nuclear reactor unsuitable for use near life.

The primary cause of major di

One Response to “The Deliberate Forgetting of the ECCS independent, Integral “Ultimate Heatsink””

  1. CaptD Says:

    Another issue is that the Earthquake knocked down a power pole which cut electricity to the reactor complex which isolated the complex from “shore power” and put it on emergency power.

    Many believe that the earthquake (EQ) also damaged a large number of steam generator (SG) tubes which started spewing super hot radioactive water/steam at rates above 500 gallons per min per tube with NO way to stop it…

    They started to add “makeup” water as fast s they could but they were unable to because of generator issues.

    I bet many reactors were damaged by the earthquake in the same way and tht not public pressure (which we now know is totally ignored by the Japanese Gov’t.) is the true reason that more reactors have not been restarted since 3/11/11. I expect to see many new replacement steam generators (RSG) installed as part of a modernization program but in reality they are covering up the fact that the SG installed on 3/11/11 were heavily damaged!

    Fukushima proved that Nature can destroy any land based nuclear reactor, any place anytime 24/7/365,

    Is the same thing is going to happen again during the next major EQ?

Comments are closed.