Awaiting Rescue

The Tsunami water level had to have reached over 30 ft. to cause this damage.

Up to Date Timeline for the Fukushima Dai-ichi nuclear power plant accident

Friday, 11 March 2011 (Day 1)

An earthquake of magnitude 9.0 occurs off the eastern coast of Japan causing the Fukushima Dai-ichi nuclear power plant (NPP) units 1, 2 and 3 to shut down automatically. Units 4, 5 and 6 have been previously shut down for outages, with unit 4 having been defueled in November 2010. Offsite power is lost. Emergency diesel generators (EDGs) provide power for the emergency core cooling systems for a short time. A tsunami strikes the Fukushima facility. Onsite EDGs stop working. The steam-driven reactor core isolation cooling (RCIC) systems and high-pressure coolant injection (HPCI) system (unit 3) provide cooling to units 1, 2 and 3. An evacuation order is issued for persons within 3 km of the Fukushima Dai-ichi NPP.

Saturday, 12 March 2011 (Day 2)

Back-up battery supplies are depleted. The ability to cool the reactors of units 1, 2 and 3 is significantly degraded or unavailable. Discharges to suppression chambers designed to control pressure within the reactor coolant system cause pressure within the primary containments to increase. Venting of the unit 1 primary containment begins. Evacuation of residents within 10 km of the Fukushima Dai-ichi NPP is underway. A hydrogen explosion occurs in the unit 1 reactor building destroying the upper structure of the building where the spent fuel pool is housed. The unit 1 spent fuel pool is exposed to the atmosphere. The evacuation zone is extended to 20 km around Fukushima Dai-ichi. Seawater is injected into the unit 1 reactor.

Sunday, 13 March 2011 (Day 3)

Venting of the unit 3 primary containment begins, and seawater is injected into the unit 3 reactor.

Monday, 14 March 2011 (Day 4)

A hydrogen explosion occurs at unit 3. The upper structure of the unit 3 reactor building is significantly damaged. The unit 3 spent fuel pool is exposed to the atmosphere. It is reported that the water level for the reactors of units 1, 2 and 3 is below the top of active fuel. Fuel damage is suspected in all three units. The containments at the three units remain intact. Seawater is injected into the unit 2 reactor.

Tuesday, 15 March 2011 (Day 5)

A fire is reported at unit 4. Damage to the top levels of the unit 4 reactor building is confirmed. Venting of the unit 2 primary containment begins. A hydrogen explosion occurs within the unit 2 reactor building. The suppression chamber (wetwell) of the primary containment is suspected to have been damaged. The unit 2 reactor building appears to remain intact. A fourth explosion occurs at the site: unit 4 sustains additional damage to the upper portion of the reactor building. The risk of water boiling in the unit 4 spent fuel pool is reported. The water level in the unit 5 reactor decreases to about 200 cm above the top of active fuel. The operational unit 6 EDG begins supplying power to the cooling systems at both units 5 and 6.

Wednesday, 16 March 2011 (Day 6)

A fire is again reported in the unit 4 reactor building in the area of the spent fuel pool. Evacuation of the 20 km zone surrounding the Fukushima Dai-ichi NPP is completed. Steam is observed coming from the unit 3 reactor building, indicating that the water in the spent fuel pool is likely boiling.

Thursday, 17 March 2011 (Day 7)

Helicopters are used to dump seawater into the unit 3 spent fuel pool for the first time. In addition, emergency crews begin spraying seawater into the unit 3 spent fuel pool using specialised fire fighting and riot control water cannons.

Friday, 18 March 2011 (Day 8)

Seawater continues to be sprayed into the unit 3 spent fuel pool. Adding cool water to the spent fuel pools of units 1, 2, 3 and 4 becomes the highest priority.

Saturday, 19 March 2011 (Day 9)

Seawater continues to be sprayed into the unit 3 spent fuel pool. Units 5 and 6 continue to be powered by an operational unit 6 EDG. Both unit 6 EDGs are operational and provide power to units 5 and 6. Spent fuel pool cooling at units 5 and 6 begins. It is reported that milk and spinach from areas around the plant have radiation levels that exceed Japanese standards. There are reports of higher than normal levels (though below allowable levels) of radioactive iodine and caesium-137 in water supplies away from the site in regions including Tokyo (traces of iodine). Tap water in Fukushima is found to have higher than allowed levels of radioactive iodine.

Sunday, 20 March 2011 (Day 10)

The spent fuel pool temperatures at units 5 and 6 are reported to be decreasing. Units 5 and 6 reach cold shutdown conditions. Crews continue to spray seawater into the unit 3 spent fuel pool. Forty tonnes of seawater have been injected into the unit 2 spent fuel pool. The unit 2 temporary power centre is powered by offsite sources.

Monday, 21 March 2011 (Day 11)

Offsite power is available to units 1, 2, 5 and 6. Power from units 1 and 2 is diverted to a temporary distribution system. Testing of equipment affected by the earthquake and tsunami begins at units 1 and 2. Power to unit 5 is switched from the unit 6 EDG to offsite power. A government directive is issued requesting relevant businesses and individuals to suspend shipment of spinach, kakina (a green vegetable) and raw milk for the time being.

Tuesday, 22 March 2011 (Day 12)

Offsite electrical power is currently available at units 3 and 4, so all six units now have external power. Testing of components continues before reconnecting power at units 1 and 2. Units 5 and 6 are in cold shutdown with cooling of the spent fuel pools continuing. Sampling of seawater downstream of the units 1, 2, 3 and 4 discharge canal detects levels of radioactive iodine (131) and caesium (134 and 137) that exceed regulatory limits.

Wednesday, 23 March 2011 (Day 13)

Crews continue to spray water into the spent fuel pools of units 3 and 4. Work to recover power for units 1 through 6 is in progress. Integrity checks of electrical equipment is ongoing in each unit and must be completed before restoring power. Lighting is restored in the main control room of unit 3. External electrical power is replaced by an emergency diesel generator in units 5 and 6.

Thursday, 24 March 2011 (Day 14)

The unit 1 reactor almost reaches 400°C, exceeding its design value of 302°C; core cooling is thus increased. Work is temporarily suspended when black smoke is observed at unit 3. No increase in radiation levels are observed. Vapour or steam is observed coming from units 1, 2, 3 and 4, marking the first time that steam is observed coming from unit 1. Three workers installing electrical cables in the unit 3 turbine building are exposed to high levels of radiation and contamination. Two workers are sent to the hospital and are suspected to have received burns from high-level beta radiation. Three workers are exposed to radiation doses between 170mSv/hr and 180mSv/hr. TEPCO now reports that 17 workers have received a dose of 100mSv or more.

Friday, 25 March 2011 (Day 15)

External electrical power to the main control room at unit 2 will be available today. Unit 1 reactor temperature decreases from about 400°C to 204.5°C as of 06:00. TEPCO suspects that nuclear fuel in the reactor or spent nuclear fuel in the pool has been damaged and that water contaminated with high radioactivity has leaked to the workspace. Surface temperatures of units 1, 2, 3 and 4 are below 20°C. The surface temperature of the spent fuel pool at unit 3 has dropped to 31°C from 56°C on the previous day.

Saturday, 26 March 2011 (Day 16)

Crews switch from spraying seawater to spraying fresh water with a boric acid injection in the unit 2 and 3 reactor pressure vessels, and from using fire engine pumps to electrical pumps. Lights in the control rooms of units 2 and 3 are restored, with lights now available in the control rooms of units 1, 2 and 3.

Sunday, 27 March 2011 (Day 17)

Periodic water spraying using a concrete pump truck continues for the unit 4 spent fuel pool. TEPCO reduces the amount of water injected into the unit 2 reactor to avoid leakages to the turbine building.

Monday, 28 March 2011 (Day 18)

Plutonium is detected in the soil of the Fukushima Dai-ichi NPP site. The detected level poses no threat to public health. TEPCO faces challenges in cooling the reactor cores as crews try to prevent leakages to the turbine buildings. Water found in the turbine buildings of units 1, 2 and 3 contains radioactive substances. The level of radiation on the surface of water puddles is more than 1 000 mSv/h in unit 2, 750 mSv/h in unit 3 and 60 mSv/h in unit 1. High levels of radiation are reported in water in a trench outside the turbine building near unit 2.

Tuesday, 29 March 2011 (Day 19)

Crews switch from spraying seawater to spraying fresh water with a boric acid injection in the unit 1 reactor vessel, and from using fire engine pumps to electrical pumps.

Wednesday, 30 March 2011 (Day 20)

Crews switch from spraying seawater to fresh water into the reactors of units 2 and 3 in order to cool the reactor cores. White smoke is observed at units 1, 2, 3 and 4. Water is again sprayed into the spent fuel pool at unit 4.

Thursday, 31 March 2011 (Day 21)

Fresh water supplies are replenished from water barged to the site. This fresh water will replenish the filtered water being used to cool the reactors. Water is sprayed into the spent fuel pools at units 1 and 3. Results of the analysis of water samples taken from the turbine building sub drains on 30 March 2011 find detectable levels of fission products.

Friday, 1 April 2011 (Day 22)

Fresh water is injected into the spent fuel pool at unit 2. Water is sprayed into the spent fuel pool at unit 4 using a concrete pumping truck.

Saturday, 2 April 2011 (Day 23)

Water is sprayed into the spent fuel pools at units 1 and 3 using a concrete pumping truck. A second barge arrives at the site with additional fresh water to replenish the filtered water being used to cool the reactors. Dose levels exceeding 1 000 mSv/h are detected in the pit where supply cables are stored near the intake for unit 2. A 20 cm crack is found on the side of this pit where water is flowing out. Efforts begin to seal the pit to minimise further leakage of water into the environment.

Sunday, 3 April 2011 (Day 24)

Fresh water is injected into the reactors at units 1, 2 and 3 using electrical pumps that are powered by an off-site source. Water is sprayed into the spent fuel pool at unit 4 using a concrete pumping truck. Efforts to seal the crack in the pit near the unit 2 intake do not reduce the leakage. Additional actions are planned to seal the crack.

Monday, 4 April 2011 (Day 25)

TEPCO announces the decision to discharge approximately 11.5 tonnes of water with low levels of radioactivity into the sea. This discharge is necessary to allow the treatment of more highly contaminated water being collected in other locations at the plant. The estimated dose to the public from this discharge is about 0.6 mSv per year for residents eating fish and seaweed from the adjacent area. This dose is about a quarter of the annual dose received by the public from natural sources.

Tuesday, 5 April 2011 (Day 25)

Water is sprayed into the spent fuel pool at unit 4 using a concrete pumping truck. The location of the leakage from the pit near the unit 2 intake structure is identified. Crews attempt to seal the leak path to minimise the uncontrolled release of contaminated water from the plant.

Wednesday, 6 April 2011 (Day 26)

The leakage of contaminated water to the sea from the pit near the unit 2 intake structure is stopped. Crews prepare to inject nitrogen gas into the unit 1 reactor containment vessel. Nitrogen gas is used to mitigate the build-up of hydrogen and oxygen mixture in the plant that could become explosive.

Thursday, 7 April 2011 (Day 27)

A magnitude 7.1 earthquake (aftershock) occurs near the Fukushima Dai-ichi nuclear power plant. This is the largest aftershock since the magnitude 9.0 earthquake on 11 March 2011. The impacts to ongoing activities at the plant are minimal. No changes in radiation levels or spread of contamination are noted following the aftershock. Cooling water is injected into the spent fuel pools at units 2 and 4.

Last reviewed: 8 April 2011

Safe Haven?

And to think, the reactor plants were designed for a Tsunami of 17 feet which was thought far and above any conceivable flood! That was based on the best scientific thought considering historical evidence. But, in their area, they experienced flooding to 45 feet.

The roof of this building in Minamisanriku, Japan was a designated safe haven, but it proved insufficiently high. Around ten people managed to cling to life there, but twenty others were swept away. -- By Asian Disaster Reduction Center

It's my understanding, that the public was also instructed that they'd find protection hiding behind Tsunami walls. We now know that these walls were no where near the height which were needed, and those who sought protection there, were the first to perish.

It's back to the drawing boards.

Unmanned Drone Aircraft Photos

Thanks to Ron Prudhomme for providing these new photos were taken from an unmanned drone aircraft, with the exception of the before photo. Captions are as provided.

Imagine, the control room operators were without lighting for almost two weeks. Oooops, the two control room photos are reversed in sequence.

This Sept. 18, 2010 aerial photo shows the Fukushima Dai-ichi nuclear complex in Okumamachi, northern Japan. (Unknown source)

In this photo released by Nuclear and Industrial Safety Agency, Tokyo Electric Power Co. workers collect data in the control room for Unit 1 and Unit 2 at the tsunami-crippled Fukushima Dai-ichi nuclear power plant in Okumamachi, Fukushima Prefecture, Japan, Wednesday, March 23, 2011. (Nuclear and Industrial Safety Agency)

In this photo released by Tokyo Electric Power Co. via Kyodo News, lighting becomes available Thursday, March 24, 2011 in the control room of Unit 1 reactor at the tsunami-damaged Fukushima Dai-ichi nuclear power plant in Okumamachi, Fukushima Prefecture, Japan. (Tokyo Electric Power Co. via Kyodo News) JAPAN OUT, MANDATORY CREDIT, NO LICENSING IN CHINA, HONG KONG, JAPAN, SOUTH KOREA AND FRANCE

In this March 20, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, the crippled Fukushima Dai-ichi nuclear power plant is seen in Okumamachi, Fukushima prefecture, northern Japan. From top to bottom: Unit 1, Unit 2, Unit 3 and Unit 4. (Air Photo Service Co. Ltd., Japan)

More Tsunami Photos

Here are additional pictures of the scenes in Japan, post-accident.

First is a front on photo of the wall of water screaming ashore followed by two showing damaged reactor building. Think of it, water weighs 62 pounds per cubic foot.

Then we view a squad of para military rescue workers marching in the snow.

A quite unique shot of electrical workers effecting repairs to electrical sub-station lines.

Incredible new video of tsunami flooding Japanese town

Watch this incredible new video of the tsunami in Japan as it completely washes over a town.

In less than 6 minutes the flooding waters reach over 20 feet above ground level. Note the long green warehouse sitting in mid-stream get washed away. Unreal!

Notice the onlookers on the 6th floor of the building opposite.

http://www.chicagotribune.com/news/nationworld/sns-viral-video-japan-tsunami-washes-away-town,0,4582163.htmlstory

U.S. Nuclear Plants Withstand Severe Events

Here is an interesting discussion of where we stand in the United States regarding severe incidents at nuclear plants.

Note, in the image the vent piping, #2, which allows depressurization of the primary containment. This post Three Mile Island, lessons learned modification was apparently not incorporated at these Japanese plants.

Note also, in the upper right hand corner of the image, a pictorial of a ventilation system in the secondary containment which exhausts through charcoal and other filters to the atmosphere. Unfortunately, this equipment is usually not hardened for severe events, nor supplied with emergency electric power.

If either of these two systems had been operable at Fukashima, destruction of the secondary buildings by hydrogen explosions, may have been averted.

U.S. Nuclear Power Plants Reconfirming Safety, Response Programs in Light of Japan Situation

U.S. Nuclear Plants Withstand Severe Events

Recent experience with earthquakes in California, Hurricane Andrew in Florida and Katrina in New Orleans repeatedly demonstrate that U.S. nuclear plants can withstand severe natural events. In each case, safety systems functioned as designed, operators responded effectively and emergency training proved successful.

When Hurricane Katrina struck New Orleans and the Gulf Coast, the devastation overwhelmed the resources of local, state and federal authorities. Katrina resulted in 1,800 deaths, damage exceeding $100 billion and millions without electric power. Entergy’s Waterford 3 nuclear energy station was in the path of the hurricane and lost offsite power, but the plant’s backup diesel generators started immediately and powered vital reactor systems for nearly five days until offsite power was restored.

The plant lost offsite communications except for satellite phones, the company’s corporate headquarters in New Orleans was evacuated and employee homes were destroyed. Yet Waterford 3 was restarted after a detailed check of plant systems, and the electricity produced there was vital to the area’s restoration. The company said information shared by the nuclear industry helped Waterford 3 prepare for the storm.

More Tsunami Photos

Deaths confirmed at Fukushima Daiichi

03 April 2011

Two workers missing since the natural disasters of 11 March have now been found dead in the turbine building of Fukushima Daiichi unit 4.

Kazuhito Kokubo and Yoshiki Terashima, aged 24 and 21 respectively, were found in the '-1' level of unit 4's turbine hall. The chairman of Tokyo Electric Power Company, Tsunehisa Katsumata, said they had been "working to protect the safety of the Fukushima power station after the earthquake and tsunami." Similar basement levels of other reactors on the site have been found to be flooded, possibly by tsunami water flowing through cabling trenches close to the seafront.

One worker also died at Fukushina Daini after suffering serious injuries and becoming trapped in the crane operating console of the exhaust stack of one of the units during the earthquake.

Like many coastal zones in northeastern Japan, the area near the nuclear power plant was utterly devastated. See image.

These three are the only deaths at nuclear power plants from the earthquake, tsunami and subsequent nuclear emergency. No effects on health or significant contamination cases have been identified among the general public evacuated from the area. The tsunami travelled up to five kilometres inland in Fukushima prefecture, causing a 1113 deaths with 4626 more people still missing. The totals for Japan as a whole are 12,087 dead and 15,552 missing as of today.

Among the 370 workers working to bring stability to the damaged reactor units of the Daiichi plant, 21 have so far experienced radiation doses of over 100 millisieverts.

Normally nuclear workers are allowed to receive a dose of 20 millisieverts over a whole year, although in practice they often receive very much less. If that limit is exceeded in any year, the worker cannot undertake nuclear duties for the remainder.

In emergency circumstances safety regulators allow workers to receive up to 100 millisieverts with the same conditions applying, that they must leave the site should that limit be reached. The 100 millisievert level is roughly the point at which health effects from radiation become more likely. Below this it is statistically difficult to connect radiation dose to cancer rates, but above this the relationship starts to become apparent when looking at a large group.

Japanese authorities have authorised exposures of up to 250 millisieverts in the efforts to bring the Fukushima situation under full control. So far no-one has been exposed to these levels.

Researched and written by World Nuclear News

Accident Chronology

Here is a nice tabular chronology of Units 1- 4.

Again, double click on images to enlarge.

Conversion dope: MpaG & Mpaabs. These are metric units of pressure. One Mega Pascal, Mpa, in English units, equals 145 pounds/sq. in.

MpaG, is gage pressure, Mpaabs, is absolute pressure.

Gage pressure + 14.5 = Absolute Pressure.

The Fukushima Event

[Emergency System Schematic, Two identical, full capacity systems termed Div. 1, Div. 2, either will perform the required safety functions. The Japanese HPCS pumps were driven by steam-turbines, not a dedicated diesel generator set as depicted.]

The following excellent information is taken from this website: http://klickitat.org/nucleartourist/fukushima.htm

This explains where the hydrogen gas came from, to relieve pressure within the reactor system, we were previously told the operators were venting to the containment. This, a poor translation from the Japanese language. This discussion clears that up, and that the gases in the primary containment were vented to the reactor building, secondary containment. Too bad they could not vent to the main plant vent through the filters provided. This would have prevented the hydrogen excursions destroying the upper structures of the reactor buildings.

Time will tell.

"The Fukushima event is slowly building to become the most significant event in the history of nuclear power. During the next couple of days, I will be working to update this page to cover all aspects of this event and also to relate this event to US reactors. Please stop back when you can."

At this point the event has been classified as an INES Level 5 accident. Although antinuclear proponents, e.g. Greenpeace, disagree, neither the IAEA nor the US Nuclear Regulatory Commission currently disagree with Japan's assessment. [Such a designation is rather academic]

As of April 2, radiation levels at locations around the Fukushima plant were trending downward. US Energy Secretary Chu estimated that 70% of the Unit 1 and 33% of the Unit 2 core had melted NY Times, April 1). The Japanese agencies have also reported concrete cracks that may provide at least one path for radioactive releases to the sea (washington Post, April 2). [DOE Sect'y. Chu hasn't a clue as to what's going on in the nuclear field]

An excellent Nuclear Crisis in Japan seminar presentation was recently provided by Dr. Alan Hanson on March 21 at the Stanford University's Freeman Spogli Institute for International Studies. It should be noted that this presentation presents an analysis based on information received to date. [Click on URL cited above]

Typical BWR Mark 1 Plant Layout

Here, reproduced from an ORNL report which itself used an original GE plant layout diagram is a new illustration for this blog. This is a BWR plant with a Mk I containment like at Fukushima Daiichi, but which shows a turbine building and typical layout. Now, this overall plant layout shown has the turbine building rotated 90 degrees as compared with Fukushima Daiichi. On the plant shown below, the turbine building is "end on" to the reactor building. However, this might help some folks who are wishing they could at least somehow picture what's going on inside the plants now that the turbine buildings, condensers, and pipe tunnels or "trenches" are making headlines. Keep this in mind when you look at the pic -- the features don't match Fukushima of course but it's a good general representation. [Double click on image to enlarge]

Japan's coast guard rescues dog from floating roof

KESENNUMA, JAPAN — Japan's coast guard has rescued a dog drifting on a rooftop off the country's coast, three weeks after a tsunami ravaged the northeast.

It was unclear how long the dog had been at sea when a helicopter crew spotted it Friday more than a mile (two kilometers) off the town of Kesennuma.

It took several hours to capture the dog because it scampered across other floating wreckage when it saw officers winching down from the chopper.

Officials said Saturday that the dog's blackish collar gives no clues about its owner. After the rescue, the dog kept quiet and ate biscuits and sausages on a patrol boat.

By Julie Makinen and Thomas H. Maugh II, Los Angeles Times

April 3, 2011, 7:51 a.m.

Officials of the Tokyo Electric Power Co. said Sunday that they had retrieved two bodies from the power plant last Wednesday. The men had rushed into the control room during the earthquake and were killed in the tsunami that followed.

NO, NO, NO, this is typical of the c_____ we get from the Main Stream Press. These two men were plant operators whose duty is to roam around the plant checking and observing the operation of equipment.

What I have been able to learn is that they were out in the turbine building when the Tsunami hit and sought shelter in a room in the basement area.

I learn that they were found with external injuries, most likely caused by being bounced around by the rushing water.

They were no way near the control room.

Here is what the Japanese Nuclear Energy Institute reports:

Missing Workers Found

Tokyo Electric Power Company has confirmed that two TEPCO employees who had been missing since the tsunami occurred on March 11 were found dead March 30 in the basement of the turbine building of reactor 4.

What's Next?

Now what? We're home free, not so? We're cooling the reactor, what more do you want me to do?

So solly Papa San, where go heat?

Good heavens, where's my Thermodynamic hat? Of course, the incoming water turns to steam.

Where go steam, Papa San?

The steam pipe of course!

But steam pipe valve closed, Papa San?

Oh, well, steam pressure then rises. That is, until very high, enough to open relief valve.

Ah so, where go steam now, Papa San?

Well, yes, the Torus suppression pool, where it is sub-cooled back to water.

But Papa San, what to do when big round pool filled?

Oh my good heavens, something has to give. Not in my pay grade. Sayonara.

Up the Creek Sans Paddle

So, here we are, our turbine has tripped, reactor scrammed, emergency diesel generator shutdown, steam turbine driven emergency feed pump shutdown, the reactor starting to heat up, the whole plant flooded out, operators cannot access emergency equipment, no electricity to power anything except battery powered control room instrumentation, and not much of that.

Even with a source of electrical power, it's of no avail as all required equipment is flood damaged, as well, most likely, inaccessible.

Isolated from the outside world for the present. Looking outside, we see nothing but desolation!

We're truly Up the creek, sans paddle/s.

What now? Nothing in the manuals for this. None-the-less, we've got to get water into the reactor, but how?

I, along with many other arm chair engineers have been pondering this problem since day one.

Here is what I would be considering.

The only source of boiler quality water, is that in the Condensate storage tank, however, it's been mainly depleted by the steam emergency feed pump. We have no means of restarting and controlling it. And then, there's only a limited amount of water remaining in the tank.

We have the fire protection system which is pressurized, I assume, with fresh water. This I would assume is no longer pressurized, thus unavailable.

We've the whole Pacific Ocean in our backyard, but how to get it into the reactor? It's use will destroy the reactors, but, now, that cannot be our concern. Release of massive amounts of radioactivity to the environs which would result from an uncooled reactor has to be our only concern.

Now, it's the seawater, or nothing. The decision is easy.

First, what do we need? I would guess that we would need at least 3,000 gallons per minute (gpm) per reactor. My choice would be large marine salvage de-watering pumps. I would not believe that any are on site, or would I believe local fire stations would have these on hand. I could be wrong. There may be large industrial plants nearby which possess these pumps. But, it would take time to assess their availability and then obtain. Corporate headquarters would be the source to search, obtain, and deliver, helicopter would be the better choice as much of the highway infastructure is unusable.

Once a large pump, diesel driven arrives, which can draw suction from the seawater intake structures, and in place, how do we dispense the water? I would think there must be fire protection distribution manifolds available which we could connect to and from which the fire protection hard piping is run.

Now, how do we deliver water to the reactors? It seems that the only accessible path would be that of the High Pressure Coolant Injection system feedwater piping, that which is the steam-turbine driven pump system previously in operation.

The problem now is, how do we cross connect from the fire protection system? I would believe that an existing cross-connection capability, a no-no, to be non-existent. What then?

We would need to punch into the feedwater piping, which is most likely a fully welded system, that is, without flanges. However, the pump itself would most likely be flanged mounted on both discharge and suction sides.

One of these flanges must be broken, and a blind flange would need to be fabricated with a fire connection fitting welded on. We would need skilled craftsman, Pipefitter/Welders, the obvious choice. Plant operators do not possess these skills.

Connect a fire house, and viola!, we're ready to roll with sea water injection into the reactor.

Another Nuclear Primer

A nuclear primer from BarCap

Posted by Tracy Alloway on Mar 15 09:33.

Here’s a nice piece of research from Barclays Capital.

The UK bank has enlisted the help of a former nuclear safety employee to discuss events at Fukushima Daiichi, the Japanese nuclear plant hovering on the edge of meltdown. For what it’s worth, BarCap’s energy team doesn’t think there was an operator error at the plant — the force of the earthquake combined with the effect of the tsunami “simply exceeded what the plant was designed to withstand.”

Here’s their rundown:

Never, never, never allow the water level in a nuclear reactor to fall below the level of the fuel. This is the mantra pounded into the minds of nuclear power plant operators all over the world (one of the authors of this report used to provide such training at a commercial nuclear plant in the US). No doubt, such training was on the minds of the Japanese plant operators as they struggled to respond to the effects of the earthquake and tsunami last Friday.

It is hard to overemphasize the importance of the “keep the fuel covered” training and design of these plants. Under standard operating conditions, the reactor water in a pressurized water reactor (PWR) or boiling water reactor (BWR, the type of all the units affected in Japan by this event) contains only trace amounts of radioactive materials. A spill or venting of it is not a threat to public safety. All the highly radioactive materials remain inside the nuclear fuel, which itself is encased in tubes, around which the reactor cooling water flows. The nuclear reaction is easy and fast to stop. Indeed, all indications are that the Japanese reactors were safely shut down when the earthquake struck.

But the halting of the nuclear reaction is only step one in caring for a plant. A few percent of the thermal power output of the reactor is produced by the radioactive decay of the daughter products of the fission process (each uranium or plutonium atom that undergoes fission produces two new atoms, which are radioactive and therefore give off energy). When the reaction is stopped, this radioactive decay heat remains – leading to an ongoing need to provide cooling water to the reactor (in fact, used fuel must be cooled for a few years before it no longer needs to be surrounded by water). If the cooling water flow in a reactor is not maintained, the water will boil off, the heat will eventually cause the tubes surrounding the fuel (fuel cladding) to fail, and the subsequent over-heating of the fuel itself will cause the radioactive materials in the ceramic fuel to be liberated into surrounding water or steam in the reactor. Once this occurs, all water or steam drawn from the reactor, and water or steam vented inside the containment building (which houses the reactor) will be contaminated. The reactor creates a wide range of radioactive daughter products, and the commonly produced iodine and cesium in the reactor water or in the atmosphere (as has been reported) are indicators that the fuel has over-heated and at least partially melted.

Keep the fuel covered with water, and the fuel will not overheat, keeping the radioactive materials safely encased in the fuel. This concept is so ingrained in nuclear plant designers and the regulators of the industry that there are automated systems to provide this function, and backups to the automated systems, and backups for the backups, and contingencies for when even those are lost. Large emergency diesel generators (think of locomotives without wheels) are installed to provide the electricity to feed electric-driven pumps. Steam from the heat still generated in the reactor is used to pump water. The redundancy of the backup water and power systems provides the assurance that in a worst-case event, even though a plant might have been damaged by some external or internal event, operators will ensure that they keep the reactor fuel covered.

But, as previously noted: The central problem behind almost every hurdle faced by the workers at the Fukushima nuclear power plant has been – and remains – a lack of power supply. Since electricity was knocked out by the Tsunami it has been impossible to run the pumps that cool the reactor cores and circulate water around storage pools used to keep spent fuel rods cooled.

This old report seems to be in agreement with my thoughts on GE's Torus Light Bulb Mk. 1 design. It is not known if the Japanese adopted the hardened vent. It appears they did not.

March 14, 2011 6:00 AM

CHRIS KNAP

THE ORANGE COUNTY (CALIF.) REGISTER

There are 23 nuclear power plants operating in the U.S. using the same General Electric Mark 1 reactors as the Fukushima Daiichi Unit 1 that suffered a hydrogen explosion on Saturday and then again early Monday, according to a fact sheet just released by the Nuclear Information and Resource Service, a Maryland-based nuclear power watchdog group.

This design, a General Electric Mark I, has been criticized by nuclear experts and even Nuclear Regulatory Commission staff for decades as being susceptible to explosion and containment failure.

According to NIRS, 35 of the 110 operational nuclear power reactors in the United States, are boiling water reactors (BWR). General Electric is the sole designer and manufacturer of BWRs in the United States. The BWR’s distinguishing feature is that the reactor vessel serves as the boiler for the nuclear steam supply system. The steam is generated in the reactor vessel by the controlled fissioning of enriched uranium fuel which passes directly to the turbogenerator to generate electricity.

The General Electric Mark 1 uses a smaller pressure suppression containment conceived as a cost-saving alternative to the larger reinforced concrete containments marketed by competitors.

San Onofre’s reactors are Pressurized Water Reactors (PWR) designed by Combustion Engineering. The PWRs use pressurized water as coolant instead of boiling the water directly in the containment vessel.

The reactors at Diablo Canyon, in Northern California, are also PWR’s, designed by Westinghouse.

A chilling NIRS fact sheet from 1996 essentially predicts what has happened in Japan in the last few days:

(The GE Mark I utilizes) a large inverted light-bulb-shaped steel structure called “the drywell” constructed of a steel liner and a concrete drywell shield wall enclosing the reactor vessel. The atmosphere of the drywell is connected through large diameter pipes to a large hollow doughnut-shaped pressure suppression pool called “the torus”, or wetwell, which is half-filled with water. In the event of a loss-of-coolant-accident (LOCA), steam would be released into the drywell and directed underwater in the torus where it is supposed to condense, thus suppressing a pressure buildup in the containment.

However, as early as 1972, Dr. Stephen Hanuaer, an Atomic Energy Commission safety official, recommended that the pressure suppression system be discontinued and any further designs not be accepted for construction permits. Shortly thereafter, three General Electric nuclear engineers publicly resigned their prestigious positions citing dangerous shortcomings in the GE design.

An NRC analysis of the potential failure of the Mark I under accident conditions concluded in a 1985 report that Mark I failure within the first few hours following core melt would appear rather likely.”

In 1986, Harold Denton, then the NRC’s top safety official, told an industry trade group that the “Mark I containment, especially being smaller with lower design pressure, in spite of the suppression pool, if you look at the WASH 1400 safety study, you’ll find something like a 90% probability of that containment failing.”

In order to protect the Mark I containment from a total rupture it was determined necessary to vent any high pressure buildup. As a result, an industry workgroup designed and installed the “direct torus vent system” at all Mark I reactors. Operated from the control room, the vent is a reinforced pipe installed in the torus and designed to release radioactive high pressure steam generated in a severe accident by allowing the unfiltered release directly to the atmosphere through the 300 foot vent stack.

Reactor operators now have the option by direct action to expose the public and the environment to unknown amounts of harmful radiation in order to “save containment.”

Read more: http://www.gazette.com/articles/reactors-114501-mark-failed.html#ixzz1IP8L5oeT

Status Update - April 2

Injection of water into the reactor vessels is now being shifted from sea to freshwater.

I have found reports that water injection is being provided at flow rates at around 2,000 gallons per minute average for reactors 1-3.

At #1 it is flowing through a feedwater line and in the other two through fire protection lines.

I do not understand the latter. However, it would seem to me that means were found to break into the feedwater system piping to effect cross connection from the fire protection system which, originally must have obtained sea water from the plants sea water intake structures through portable fire pumps.

Now, with U. S. Navy freshwater barges on-site, the use of sea water can be dispensed with.

Three Blind Mice

At about 4 am Saturday, March 12, operators determine that water level in Reactor #3 has dropped sufficiently to expose the core and in another hour they begin to vent the reactor vessel in unit 1 to the torus suspension pool. By 11 am, they begin venting on unit #2.

Suddenly, at 3;56 PM, the reactor building of unit #1 is rocked with a violent explosion. This was the result of the ignition of hydrogen which had been released into the structure. The evolution of hydrogen was undoubtely due to the oxidation of the zirconium cladding surrounding the fuel pellets.

Where this hydrogen came from has not been discovered. My best guess is that a previous hydrogen burn had occurred within and breaching the reactor containment, releasing further hydrogen gas into the reactor building. Previous studies were of the opinion that such an event in spent fuel pool would not occur before 100 hours or so after loss of cooling.

It is noteworthy to note that a similar hydrogen burn occurred some 10 hours into the incident at Three Mile Island . However, because of the enormous free volume within the containment, the resultant pressure rise reached only to a maximum of 28 psig. Reactor containment building are built to a design pressure of about 60 psig, but should be able to withstand twice that. By contrast with the PWR plants with a free volume of about 2 million cu. ft., the BWR containment here fits rather tightly, like a skirt around the reactor system.

Water, Water, Everywhere, But, Not a Drop For Use

Returning now to the timeline of events. It is now late in the afternoon of Friday. Manning the control rooms of the units are probably some 5 to 10 operators. In reactor #1 we most likely have a Control Room Supervisor, Senior Control Room Operator, Control Room Operator, and perhaps some four Plant Operators who roam around the plant making observations, checking equipment operation, etc. In units 3 & 4 and also 5 & 6, we most likely have central control rooms which might employ a second Control Room Operator.

Throughout the nuclear plant facilities, I would imagine many of the structures have been destroyed by the flooding waters, and many of the workers lost. Roads are filled with debris. The relief crew most likely lost their homes and/or lives, or were recovering their senses, gathering their bearing, or looking for family members.

All local fire stations and their crews may well have been lost. Those stations and crews surviving, had their hands full responding to emergency calls.

Within the control room, they have lighting, some instrumentation monitoring and control functions, all taking power from the station batteries.

There most immediate concern was the maintenance of emergency cooling water flow to the reactor vessels. This was being accomplished by the High Pressure Cooling Water System. However, the batteries are depleated just before 3 AM Saturday morning.

The plant operators are now, completely in the dark. We've water, water, everywhere, but no way to get any into the reactors.

The possibility existed that the local fire protection system was operable, but this seems unlikely, as the pumps provided were either damaged by the Tsunami, or without emergency electric power. Any diesel driven fire pumps would also most likely inoperable due to flooding.

How long before relief help arrived and headquarters was able to assemble their response team is unknown. It wouldn't have been easy!

In the meantime, water in the reactor vessels and spent fuel pools began to rise in the absence of the addition of water. There was no way, the operators could have accomplished a jury rigged supply.

They were now, totally in the blind, without the means to alleviate the situation.

Emergency Cooling Systems

There are two main emergency core cooling systems, each consisting of two separate & identical trains of components. Either train sets will satisfy their required functions.

As previously noted, upon the tripping of the main steam turbine, and scramming of the reactor, the High Pressure Cooling system actuated.

The high pressure coolant injection (HPCI) system is an independent emergency core cooling

system requiring no auxiliary ac power, plant air systems, or external cooling water systems for the purpose of providing make up water to the reactor vessel for core cooling under small and intermediate size loss of coolant accidents. The high pressure coolant injection system can supply make up water to the reactor vessel from above rated reactor pressure to a reactor pressure below that at which the low pressure emergency core cooling systems can inject.

The low pressure emergency core cooling systems consist of two separate and independent systems, the core spray system and the low pressure coolant injection (LPCI) mode of the residual heat removal system.

The core spray system consists of two separate and independent pumping loops, each capable

of pumping water from the suppression pool into the reactor vessel. Core cooling is accomplished by spraying water on top of the fuel assemblies.

The low pressure coolant injection mode of the residual heat removal system provides makeup water to the reactor vessel for core cooling under loss of coolant accident conditions. The residual heat removal system is a multipurpose system with several operational modes, each utilizing the same major pieces of equipment. The low pressure coolant injection mode is the dominant mode and normal valve lineup configuration of the residual heat removal system. The low pressure coolant injection mode operates automatically to restore and, if necessary, maintain the reactor vessel coolant inventory to preclude fuel cladding temperatures in excess of 2200EF. During low pressure coolant injection operation, the residual heat removal pumps take water from the suppression pool and discharge to the reactor vessel.

Nuclear Basics

Nuclear Basics

I have been asked to provide a layman's understanding of how a reactor works and how spent fuel elements are handled.

Commercial nuclear reactor plants are essentially, not unlike steam boiler power plants, with the exception that the heat which generates the steam which drives the turbine-generator unit, is produced by the fission of the uranium nuclear fuel. rather that a boiler powered by oil or natural gas.

For example, my first assignment in the industry was in 1965 when I was employed by the Bechtel Corporation as a mechanical start-up engineer at the San Onofre Nuclear Plant near San Clement, Ca. Of our six mechanical engineers, the Chief engineer and one other, were graduates of the California Maritime Academy at Vallejo, Ca., another from the U. S. Maritime Academy at Kings Point, N. Y., another from the New York Maritime Academy at Fort Schyler, N. Y., and then two of us from the Naval Academy. Both the Westinghouse Nuclear system and his Westinghouse Turbine erector Chief Engineers, were also Cal. Maritime graduates. My last two seagoing assignments in the Navy were as Chief Engineer on oil fired boiler ships. Maritime boiler/turbine plants differing mainly, only in size, compared to stationary power plants.

Control rods containing neutron absorbers are driven in and out of the core controlling the heating process and steam production.

Feedwater supplied to the reactor core, passing through the core region, is flashed to steam, thereafter, it is transported to the turbine where it gives up the energy contained in the steam through turbine blades. The steam exhausted from turbine enters a large chamber, called a condenser, where it passes over tubes cooled by sea water. The condensed cooled steam is returned through condensate and feedwater piping back to the reactor to continue the closed loop process.

The reactor core is usually comprised of three regions of uranium fuel rods packaged into fuel bundles, of different percentages of uranium 235, averaging about 3%.

In general, a third of the core is exchanged annually, the fuel removed, being placed in a spent fuel pool for continued cooling and covered with about 10 feet of water which provides the necessary shielding for the protection of plant workers.

Cooling of the spent fuel is provided by a closed loop system with the heat transfered to sea water through an heat exchanger.

As I remember, spent fuel pools were designed to contain 1-1/3 cores. This allows for the 1/3 core to cool sufficiently before being shipped off-site to a recycling facility. This also provides for the complete forced off-loading of a core load in the case of the need for work on the reactor vessel.

"If you take a fuel rod bundle out of a reactor and put it in a pool, you have to leave it for five years before you can take it out. They don't produce a lot of heat, but it is unrelenting," said Richard Lahey, who was General Electric's head of safety research for boiling water reactors when the company installed them at Fukushima.

Lessons Not Learned

Nuclear Energy Institute Report On Japan's Nuclear Reactors, March 30, 2011 (12 PM EDT)

WEDNESDAY, 30 MARCH 2011 12:44 PRESS RELEASE LATEST NATIONAL NEWS

Washington, D.C.--(ENEWSPF)--March 30, 2011 - UPDATE AS OF 12 P.M. EDT.

Operators of nuclear power stations in Japan have been urged to ensure their facilities have emergency power sources.

Industry Minister Banri Kaieda Wednesday attributed the nuclear emergency in Japan to the loss of cooling systems at the Fukushima Daiichi nuclear power plant, the Japan Atomic Industry Forum reported. He told utility companies they should have mobile generators on hand to cool their nuclear reactors as an added safety measure.

......

Ah so! Leave it to our politicians.

And what will we do with these mobile generators?

We already have redundant emergency diesel generators in place, all damaged along with the equipment for which they're to power!

What are they to be connected to when all switchgear is water damaged?

What will they power? All required emergency electric motor driven pumps have been water damaged.

What, what, what?

They appear to be of the same ilk as our Main [Lame] Stream Press!

Background

Shortly before 3 pm on the afternoon of Friday, March 11, a massive earthquake of approximately 9.0 magnitude struck offshore of Japan.

At the Fukushima Daichi plant, Units 1, 2 and 3 were in operation. The other three units were in various conditions of maintenance shutdown. As designed these three reactors shutdown automatically in response to the earthquake loads. Although, this earthquake exceeded by a large margin, the earthquake accelerations for which the reactors were designed, it appears that no adverse affect resulted.

1 Core with fuel rods

3 Equipment pool

5 Fuel storage pool; spent fuel area

8 Reactor pressure vessel

10 Secondary concrete shield wall

11 Free standing steel drywell

16 Vent header

17 Downcomer pipe

18 Water (wetwell)

20 Basement

21 Reactor building

22 Refuelling platform

24 Pressure supression chamber (runs in a torus around the reactor)

25 Vent (81 inch diameter)

26 Crane

27 Spent Fuel

29 Feedwater pipe

30 Steam pipe (to turbine-generator)

31 Control rod drives

39 Control rods

40 Steam separators (water normally goes to this level)

41 Steam dryer

The earthquake also caused the loss of electrical power from the national electrical grid. As a result, the redundant emergency diesel generators were activated on loss of external power which were provided to power all required emergency loads. Note, two full capacity diesel generator units are required at nuclear plants as required by the Single Failure Criterion design requirement. This requires that all emergency functions be available assuming a single failure of any given component.

Simultaneously, the emergency steam turbine driven feedwater pump was activated, providing feedwater cooling to the reactor vessels of units 1, 2 & 3.

Flowing through the reactor core fuel elements, this water was turned to steam by the residual heat remaining in the fuel rods. This steam, in turn, was directed downward into the torus water pool, where it was condensed.

Some 15 minutes later, The tsunami unleashed by the earthquake struck the Fukushima facility flooding out the emergency diesels, the electrical switchgear, and all the required electrical driven emergency pump motors.

With the loss of power from the grid and the damage to the diesel generators, the plant was now totally without power in which to drive emergency equipment. The only remaining emergency function remaining was the steam-driven pump which would only be functional for a few hours when the steam pressure had been reduced below working pressure.

At this time, emergency cooling water pumps should have been activated, but, had no electrical power available to power them, however, this would have been to no avail, as they had been damaged by the flooding waters.

Subsequently, without electric power, without cooling, the pressure within the nuclear units began to rise. This pressure buildup is the result of residual decay heat causing the coolant, which is not being circulated, to evaporate

The central problem behind almost every hurdle faced by the workers at the Fukushima nuclear power plant has been – and remains – a lack of power supply. Since electricity was knocked out by the Tsunami it has been impossible to run the pumps that cool the reactor cores and circulate water around storage pools used to keep spent fuel rods cooled.

Tsunami Aftermath

Here are three pictures which vividly portray the extent of the flooding caused by the earthquake induced Tsaunami.

Now, visualize the extend of the damage which occurred at the damaged reactors.

Like all Western nation reactor plants, these reactors were designed for a Tsaunami greater than ever recorded with the large margin given for uncertanties. In this case, they were designed for Tsaumi flooding of approximately 16 feet. We are now advised that the plant saw a water level of about 45 feet.

Tsunami

Among the natural phenomenon for which these plants were built, was an earthquake induced Tsunami.

Along some coastal areas of Japan where population density is high, Tsunami walls are extensively built as Tsunami protection. Japan is the more prominent country which has used tsunami walls to have protection against locally generated tsunami. These walls are of 4.5 metres. Theses walls are also designed to redirect water in the event of a Tsunami facilitating floodgates and channels.

Variations in height of protection in Japan varied, some up to 30 feet which appears to be based on local topographic features.

At these reactors, a design of about 16 feet was provided. This height was considered well above any conceivable scenerio. The actual wall estimated at the plant was about 45 feet.

Obviously, it's back to the drawing boards.

I understand that the San Onofre reactors at San Clemente are designed for a Tsunami of 30 feet. News to me.