Ferdinand E. Banks says

Joseph Somsel says

You are absolutely correct - the key to the core damage was the failure of the RCIC system. I am a nuclear engineer and I've been professionally involved in the key sequence to meltdown - station blackout - for over 25 years. RCIC is the front line system for dealing with station blackout and has an analogue in the Auxiliary Feedwater System (AFW) in PWR-type reactors. Both use essentially the same hardware - a small steam turbine that is so ancient a model is reportedly in the Smithsonian Museum.

More contemporary reactor models like the Advanced Boiling Water Reactor (ABWR) and recently constructed PWRs in China and Europe have moved to a newer, more compact, and more reliable component that can operate without any electricity and can even run submerged (formal qualification testing pending).

ALL light water reactors should have their old RCIC/AFW steam turbines replaced with the new model from the ABWR. This would be the biggest improvement possible to come from the Fukushima event, if mandated by our national regulators along with a smaller containment vent modification for BWRs.

This is my personal professional opinion but one I've convinced my management to support so that we are now offering this modification commercially for both BWRs and PWRs world-wide.

Please pardon this hint of commericalism here but it is an position I sincerely hold and can analytically defend.

Len Gould says

Michael Keller says

Fukushima was a "dead-man-walking" after just a few short hours of no water.

Steam turbines work well as long as they are not over sped (slug of water showing up) or valves do not seize up (motor operator over-torques, jamming the valve).

Thinking that an "unsinkable" ship has been created invariably leads to misfortune.

Constant vigilance is required and that comes from the lads taking responsibility for "their" plant. Unfortunately, management's attitude can breed complacently and fear of reprisal for "rocking-the-boat". Better to deal with all issues directly and in the open. The results are always better.

Joseph Somsel says

Only a single motor-operated valve is usually required, powered by DC from the safety-related station batteries with a manual handwheel for over-ride. This admits steam from the reactor to the turbine. However, it is typically one of the most trouble-prone valves in the plant.

These pumps are always on the ground floor or in the basement below grade. There is plenty of possible water sources at a plant, it is a matter of having hard-piped connections in-place for when you need them in a hurry. Currently US plants have to demonstrate water for, usually, 4 hours and in some rare cases, 8 hours.

It now should be obvious that this equipment and its water supply needs a serious upgrade. When we do our probablistic risk assessments (PRAs) on plants, this is typically the most risk-significant equipment in the plant and station blackout the most probable way to a meltdown.

Expect the NRC to take action on this issue, upping the requirements on plants. They have already ordered most BWRs to add vents that can improve extended station blackout coping. The decay heat is discharged as steam from the reactor into the suppression pool which, over a few hours, begins to boil. One has to vent off this steam to take away the decay heat.

Malcolm Rawlingson says

However given the anti nuke heretics are prone to hyperbolic assumptions about anything related to the nuclear industry the use of the phrase...

"The 3/11 Fukushima disaster has been considered among the most lethal in the last decade" is merely an extension of that ill-informed rhetoric.

Lethal means that the incident has killed people. No-one and I repeat NO-ONE was killed by Fukushima and no-one is likely to die as a result of exposure to radiation released. While the amounts of radiaoactive materials released from the reactors are above legal limits there is no significant danger to the public and most of the measures taken are precautionary. If people are concerned about this amount of radiation then we should immediately ban all X-ray, CRT and other diagnostic imaging systems that use radioactive materials as their source. We should also evacuate many populations from areas of the world where background radiation is far above those at Fukushima. These doses are now considered "lethal"

Of course we should also ban the entire coal industry which acutely (they die straight away) kills thousands of miners every single year and chronically (slowly kills over a period of time) tens of thousands more through black lung and numerous other respiratory diseases. Apparently dying as a result of coal extraction is OK and not a humanitarian disaster. Being exposed to radiation as "excessive" as a few X-rays is cause for alarm.

Much of the damage at Fukushima was the result of operators having to find the local mayor to get permission to vent the hydrogen from the reactor. Had this been done earlier substantially less damage would have occurred. Unfortunately the Mayor was not by his phone (it got washed away by the Tsunami....which lethally drowned tens of thousands of poor souls).

So while we in the nuclear business consider this a serious event it was not and is not lethal because no one was killed by Fukushima and no one will be.

Malcolm

Harry Valentine says

The Fukushima disaster opens the door to discussion re linking undersea power cables amongst Japan, South Korea and China, given that the Korea Strait and the Yellow Sea are relatively shallow. Japan could then purchase electric power from South Korea and Japan, including nuclear electric power.

Ferdinand E. Banks says

Shehu Khaleel says

Christopher Kenny says

Interesting article. I recently worked with futurist and author, Joel Barker, to develop an Implications Wheel® to understand the implications of a Fukushima-type disaster at a nuclear power plant in the Midwest region of the United States. The Wheel captured the significant qualitative risks and opportunities for the nuclear power industry and for emergency management agencies were such an event to occur. Individuals from both inside and outside the industry participated and the results were fascinating. The nuclear incident Wheel may be viewed at http://implicationswheel.com/examples/hypothetical_nuclear_plant_incident. Happy to discuss further details with you and others. ckenny@stargroupconsulting.com.

bill payne says

BEFORE THE NEW MEXICO PUBLIC REGULATION COMMISSION

IN THE MATTER OF THE APPLICATION OF PUBLIC SERVICE COMPANY OF NEW MEXICO FOR APPROVAL OF RENEWABLE ENERGY RIDER NO. 36 PURSUANT TO ADVICE NOTICE NO. 439 AND FOR VARIANCES FROM CERTAIN FILING REQUIREMENTS

PUBLIC SERVICE COMPANY OF NEW MEXICO,

Applicant ) ) ) ) ) ) ) )

Case No. 12-00007-UT

MOTION FOR LEAVE TO INTERVENE AND REQUEST FOR DISCOVERY

http://www.prosefights.org/pnmrider/pnmrider.htm#motion

William H Payne, author of the PNM Alternate Report: Electric Integrated Resource Plan for the Period 2008-2027, and intervenor in CASE NO. 11-00369-UT in compliance with NMAC 1.2.2.23A hereby requests to intervene.

Our complaint is that rate decisions are being determined by liberal arts 'educated' BS artists who do not rely on facts to justify decisions.

Robert Wichert says

Fred Linn says

The reliability of such a safeguard system is absolutely, completely 100% reliable under any conditions----even completely unforeseen conditions.

dennis baker says

Dennis Baker 106-998 Creston Avenue Penticton BC V2A1P9 cell phone 250-462-3796 Phone / Fax 778-476-2633

Michael McGovern says

That was always THE argument against nuclear.

In fact, your excersise in hindsight is actually an argument against nuclear safety because it underlines what is really wrong with that source of energy: the human factor; the ability to overlook the BLOOMIN' OBVIOUS

If the cream of global engineering can't get such SIMPLE safeguards right in times of economic excess and social stability, how are poorer, less able, less stable societies going to get it right? Some people don't know this, but large concentrations of power and money attract mafia mentalities, which tend to interfere with scientific utopias.

Britain (for example) could make its trains run on time IF ONLY ... We all know HOW, thank you very much. We simply cannot do it.

Oh, but hang on, we have a major nuclear programme ahead. Oh well, not to worry, nuclear power is harldy TRAIN SCIENCE is it?

HIMADRI BANERJI says

A point made by Len Gould got immersed/submerged in the hum drum of the discussions around the Nuclear core meltdown and the subsequent impacts. I reiterate the point here and would like serious comments on the same. Once the meltdown conditions begin yes we may have extremely high heat fluxes to deal with , but what happens before the same, as power supply to the cooling water pumps fail?

As Len mentions in his comment, If there be a submersible steam turbine driven auxiliary feed water pump, driven by the the steam generated from the reactor, there would be a continuous circulation of fresh water to the core and this would prevent the core reaching the meltdown conditions.

Why can this simple design be not made to work time in and again!

Fred Linn says

You are assuming that human operators have a built in safety mode that is infallible at preventing a disaster caused by human error, or intention.

There is no such human factor.

Take a clue from the difficulty of trying to prevent suicide bombings.

Jon Wharf says

Shehu Khaleel says

bill payne says

BEFORE THE NEW MEXICO PUBLIC REGULATION COMMISSION

IN THE MATTER OF THE APPLICATION OF PUBLIC SERVICE COMPANY OF NEW MEXICO FOR APPROVAL OF RENEWABLE ENERGY RIDER NO. 36 PURSUANT TO ADVICE NOTICE NO. 439 AND FOR VARIANCES FROM CERTAIN FILING REQUIREMENTS

PUBLIC SERVICE COMPANY OF NEW MEXICO,

Applicant )

Case No. 12-00007-UT

MOTION FOR LEAVE TO INTERVENE AND REQUEST FOR DISCOVERY

http://www.prosefights.org/pnmrider/pnmrider.htm#motion

Let's see what happens.

Malcolm Rawlingson says

Looking at charts like this is informative, one must remember that it may not be a reflection of what the plant itself was doing. The instruments and cables that measure the data portrayed on the above charts were subjected to severe event so what you see recorded here may or may not be an accurate representation of how the plant actually responded. To determine that requires extensive investigation and cross checking of data as is being done so it is somewhat dangerous to draw conclusions by observing some charts from the control room. There are many things that can affect the recording of data and it is necessary to cross check this information against other event timelines, eye witness reports and many other sources to be sure you have the right answers. A good attempt at analysis but think we should leave that to the accident investigators to determine exactly what went wrong and why.

Unfortunately much of what I see posted is a wonderful dose of 20-20 hindsight.

To those with little knowledge the picture painted is one of complete neglect by TEPCO and it would appear that the Company had no protection against Tsunamis. That of course is untrue. The Tsunami sea wall built by TEPCO in front of the plant to protect it was several meters in height and strong enough to withstand a mountain of sea water crashing into it. It is one of the highest sea walls in the area. The wall survived both the earthquake and the Tsunami however it was not high enough to prevent the largest Tsunami in Japanese History from rolling over it.

Of course if you think that you have constructed a wall high enough to keep Tsunami out then logically, why would you need to waterproof the generator sets or move them to higher ground. Obvious in 20-20 hindsight after the country experiences the worst earthquake in recorded history not so obvious before hand.

If all the bar room experts were so knowledgeable about the likelihood of waves that large from an earthquake that big then I would suggest that next time they share it with the poor souls who were wiped out by it so that they could protect themselves. Clarly lots of people in Japan did not think this was possible - not just the people at TEPCO.

Furthermore it was not just the nuclear operators that did not account for the possibility of such a devastating wave. Municipalities up an down the coast built sea walls lower than TEPCO built and had their cities and towns flooded out of existence when they failed to do their job. Clearly the entire country - not just TEPCO failed to prepare for the worst.

There are many lessons to be learned from Fukushima one of which is that we need more people with 20-20 FORESIGHT who can tell us about these things before they happen. That way 30,000 people would not have died.....remember none of them as a result of the nuclear power plant.

As Fred Banks said earlier renewables will have a small role to play but the lions share of electricity generation will be coal and nuclear for many years to come.

As we speak there are 62 nuclear power plants under construction and due to come on line between 2013 and 2020. The USA is building two new ones at Vogtle site in Georgia and nations around the world are turning to nuclear power to meet their burgeoning energy needs. Hardly an industry in decline is it. The Chinese are looking at the macroeconomic picture as Fred Banks states which is why there will be hundreds of reactors in operation in China by 2050.

While many like to paint renewables as the saviour of mankind I am sorry to say they are going to be sadly disappointed. Politicians may paint rosy pictures with smoke and mirrors but the facts clearly show the truth that renewables are orders of magnitude short of meeting the expectations of their proponents. Malcolm

Malcolm Rawlingson says

For steam turbine to work steam conditions must be controlled within tightly regulated parameters of temperature and pressure....which appear to me to be exactly the things you do NOT have in a reactor in an accident condition. All steam is not created equal so I question whether such a proposal is feasible. Additionally all accidents are not created equals so what may work for one accident may not work for another.

I think also that seismically qualifying a steam turbine and associated generator to operate flawlessly following a magnitude 9 earthquake might be a tad difficult to do.

Good theory but a non-starter practically.

Malcolm

Malcolm Rawlingson says

Malcolm

Joseph Somsel says

Most installed turbines in this service are rather antiquated, require electrical control power, and can not be submerged. A few newer plants have a more modern design that requires no electrical power, has no shaft seals to leak potentially radioactive steam, and should be submergible. The modern design should be considered a desirable backfit capable of meeting Fukushima conditions and challenges.

Malcolm Rawlingson says