Japan Need to Widen Evacuation Zone

A massive tsunami which resulted from the quake killed at least 11,417 lives, with 16,273 people still reported missing by police, three weeks on along with a massive nuclear crisis in Japan.

Recent  radioactive iodine levels in seawater near the plant reached a new record - 4,385 times the legal limit. It was the highest reading since the quake which hit the plant on 11 March.

UN nuclear monitors have advised Japan to consider expanding the evacuation zone around the stricken reactors at the Fukushima Daiichi plant.

An exclusion zone with a radius of 20km (12 miles) is currently in place but the UN says safe radiation limits have been exceeded 40km away.

Radioactive material may be leaking from the damaged plant continuously, the country's nuclear and industrial safety agency (Nisa) said. The plant's operator, Tokyo Electric Power (Tepco), announced on Wednesday that the four stricken reactors would be decommissioned.

Seawater Radioactive Readings of FUKUSHIMA 31/3/2011

According to Nuclear and industrial Safety Agency (NISA) the new radioactive iodine levels in seawater near the plant - 4,385 times the legal limit. Radioactive iodine was estimated to be 3,355 times the legal limit On Wednesday, while previously the figure had been put at 1,850 times the legal limit.

Radioactive iodine was blamed for the high incidence of thyroid cancer among children exposed to fallout from the Chernobyl nuclear disaster in 1986.

Nisa's director-general, Hidehiko Nishiyama, told reporters the new levels did not present a health risk because nearby residents had already been evacuated.

Officials point out that no fishing is allowed in the area. Because the radiation should disperse as it is carried away by the tides, they do not think there will be a serious threat to marine life.

Directional Drilling

An oil well is a general term for any boring through the Earth's surface designed to find and produce petroleum oil hydrocarbons. Usually some natural gas is produced along with the oil, and a well designed to produce mainly or only gas may be termed a gas well.

 The earliest oil wells were drilled percussively by hammering a cable tool into the earth. Soon after, cable tools were replaced with rotary drilling, which could drill boreholes to much greater depths and in less time. The record-depth Kola Borehole used non-rotary mud motor drilling to achieve a depth of over 12 000 meters (38,000 ft). Until the 1970s, most oil wells were vertical (although different lithology and mechanical imperfections cause most wells to deviate at least slightly from true vertical).

However, modern directional drilling technologies allow for strongly deviated wells which can, given sufficient depth and with the proper tools, actually become horizontal. 

This is of great value as the reservoir rocks which contain hydrocarbons are usually horizontal, or sub-horizontal; a horizontal wellbore placed in a production zone has more surface area in the production zone than a vertical well, resulting in a higher production rate.

The use of deviated and horizontal drilling has also made it possible to reach reservoirs several kilometers or miles away from the drilling location (extended reach drilling), allowing for the production of hydrocarbons located below locations that are either difficult to place a drilling rig on, environmentally sensitive, or populated.

Pozzolanic Chemistry in Cement

Pozzolana blended Portland cement produce a lower porosity concrete, which makes it more resistant to water absorption and spalling. It is also resistant to forms of corrosion induced by sulfates.At the basis of the Pozzolanic reaction stands a simple acid-base reaction between calcium hydroxide, also known as Portlandite, or (Ca(OH)2), and silicic acid (H4SiO4, or Si(OH)4). For simplifying, this reaction can be schematically represented as following:

Ca(OH)₂ + H₄SiO₄ —> Ca²⁺ + H₂SiO₄^2- + 2 H₂O —> CaH₂SiO₄· 2 H₂O

or summarized in abbreviated notation of cement chemists:

 

CH + SH —> CSH

The product of a general formula (CaH2SiO4 · 2 H2O ) formed is a calcium silicate hydrate, also abbreviated as CSH in cement chemist words. The ratio Ca/Si, or C/S, and the number of water molecules can vary also the above mentioned stoichiometry may differ slightly.

As the density of CSH is lower than that of portlandite and pure silica, a consequence of this reaction is a swelling of the reaction products. This reaction may also occur with time in concrete between alkaline cement porewater and poorly-crystalline silica aggregates. This delayed process is also known as alkali silica reaction, or alkali-aggregate reaction, and may seriously damage concrete structures because the resulting volumetric expansion is also responsible for spalling and decrease of the concrete strength.

Geothermal Energy Facts: Geothermal Energy Pros and Cons

There is much talk about climate change, and the search for viable renewable energy sources. Everyone knows about the likes of solar, wind and wave power. But fewer have heard of geothermal, or know how does geothermal energy work. So here are some geothermal energy facts, which may help you understand the benefits and restrictions of geothermal energy.

How Does Geothermal Energy Work

The principle of this form of energy is quite simple. The ground beneath our feet gets heated by the sun on a daily basis. However, it is also a great insulator, and so retains a vast amount of this heat as stored energy. The idea is that pipes are run through a fairly large area of ground several feet down, where the temperature is more constant. Then, water is passed through the pipes, heating it.

The primary use for this type of energy is heating, as a regulated temperature can be achieved constantly with little variation dependent on time of year. It can also be used over larger areas to provide hot water, but this needs more time in the ground so more pipework and a greater area.

The Pohutu Geyser in New Zealand erupts with a natural blast of the Earth's interior heat.

Geothermal Energy Pros and Cons

The advantages of geothermal energy are that once the initial investment is paid for, and energy is relatively free. And it's clean. There is little or no reliance on power from gas or electricity to provide heat, which is one of the main uses of energy in the home. The main need for electricity to run this system is for pumps to pump the water through the system. The advantages of geothermal energy are that it is cheap, once the ground works are done, and incredibly green energy. There are no emissions from the provision of heat for the home and water.

 Use of Geothermal Reservoir as power Generation

The disadvantages of geothermal energy are the initial expense and the amount of land required. It can cost thousands to dig out the land and lay the pipes. This is one of the geothermal energy problems and why it is not widely used. Another of the disadvantages about geothermal energy is that it requires a fair sized piece of land to implement. People with a fair-sized garden will be ok, but it is not possible to install in the yard of a Victorian terrace.

One possibility that some people use is a new system where pilings are drilled into the ground, with the pipe work in the foundations. Because pilings go much deeper into the ground, they gain the distance that is required underground to heat the water. This is great for new build homes, but obviously cannot be achieved in older homes.

How Many People Use Geothermal Energy

Because of the initial costs and need for space, geothermal energy is not widely used. It is becoming more popular in single builds however, and could provide an efficient method for providing heat for buildings such as apartments and new build housing estates through district heating systems or individual heating through pipes in the pilings. Because it is so expensive, it is unlikely that house building companies will install the systems in homes in the near future. But hopefully it could become the way we provide all our heat energy needs in the future.

Update of FUKUSHIMA Crisis(30/3/2011)

The massive 9.0-magnitude quake and the tsunami on 11 March have killed more than 11,000 people, with at least 16,700 people still missing across north-eastern Japan along with a massive Nuclear crisis. Today’s update of this crisis are:

*  Reactor 1: Damage to the core from cooling problems. Building holed by gas explosion. Highly radioactive water detected in reactor

* Reactor 2: Damage to the core from cooling problems. Building holed by gas blast; containment damage suspected. Highly radioactive water detected in reactor and adjoining tunnel

* Reactor 3: Damage to the core from cooling problems. Building holed by gas blast; containment damage possible. Spent fuel pond partly refilled with water after running low. Highly radioactive water detected in reactor

* Reactor 4: Reactor shut down prior to quake. Fires and explosion in spent fuel pond; water level partly restored

* Reactors 5 & 6: Reactors shut down. Temperature of spent fuel pools now lowered after rising high

Rising Radioactivity of Fukushima Seawater

According to Japan's nuclear safety agency, test performed earlier on water in one section near the Fukushima Daiichi plant's reactor 1 indicated the iodine level at 1,850 times the legal limit which is now  found at 3,355 times the legal limit.

However, an official said the iodine would have deteriorated considerably by the time it reached people. Radioactive materials are measured by scientists in half-lives, or the time it takes to halve the radiation through natural decay.

"Iodine 131 has a half-life of eight days, and even considering its concentration in marine life, it will have deteriorated considerably by the time it reaches people," Hidehiko Nishiyama, deputy director-general of Japan's nuclear safety agency told a news conference.

Half-lives range from fractions of a second to billions of years.

Iodine 131 was blamed for the high incidence of thyroid cancer among children exposed to fallout from the Chernobyl nuclear disaster in 1986.

Alongside uranium, other elements of greater concern are those with much longer half-lives. These include caesium, which is easily taken up by plants and animals and can be inhaled through dust, ruthenium, strontium and plutonium.

Workers at Japan's quake-hit nuclear plant are trying to prevent radioactive water from seeping into the sea.

Highly radioactive liquid has been found inside and outside several reactor buildings.

Small amounts of plutonium have also been detected in soil at the plant - the latest indication that one of the reactors suffered a partial meltdown.

Plant operator Tepco and the safety agency say the exact source of the radioactive leak is unknown. But, like the discovery of plutonium, the high levels of radiation found inside and outside reactor buildings are likely to have come from melted fuel rods.

Theories for the leak centre on two possibilities: steam is flowing from the core into the reactor housing and escaping through cracks, or the contaminated material is leaking from the damaged walls of the water-filled pressure control pool beneath the No 2 reactor.

The plutonium - used in the fuel mix in the No 3 reactor - is not at levels that threaten human health, officials said.

Engineers are battling to restore power and restart the cooling systems at the stricken nuclear plant.

Update of FUKUSHIMA Crisis(29 /3/2011)

The massive 9.0-magnitude quake and the tsunami on 11 March have killed more than 11,000 people, with at least 16,700 people still missing across north-eastern Japan along with a massive Nuclear crisis. Today’s update of this crisis are:

• Reactor 1: Damage to the core from cooling problems. Building holed by gas explosion. Highly radioactive water detected in reactor
• Reactor 2: Damage to the core from cooling problems. Building holed by gas blast; containment damage suspected. Highly radioactive water detected in reactor and adjoining tunnel
• Reactor 3: Damage to the core from cooling problems. Building holed by gas blast; containment damage possible. Spent fuel pond partly refilled with water after running low. Highly radioactive water detected in reactor
• Reactor 4: Reactor shut down prior to quake. Fires and explosion in spent fuel pond; water level partly restored
• Reactors 5 & 6: Reactors shut down. Temperature of spent fuel pools now lowered after rising high
• Plutonium: Found at five locations in soil - levels said to represent no danger to human health

Underwater Setting Property of Pozzolana

Pozzolana is a aluminous and siliceous material which reacts with calcium hydroxide in the presence of water. This forms compounds possessing cementitious properties at room temperature which have the ability to set underwater. It transformed the possibilities for making concrete structures, although it took the Romans some time to discover its full potential. Typically it was mixed two-to-one with lime just prior to mixing with water. The Roman port at Cosa was built of Pozzolana that was poured underwater, apparently using a long tube to carefully lay it up without allowing sea water to mix with it. The three piers are still visible today, with the underwater portions in generally excellent condition even after more than 2100 years.

Modern pozzolanic cements are a mix of natural or industrial pozzolans and Portland cement. In addition to underwater use, the high alkalinity of pozzolana makes it especially resistant to common forms of corrosion from sulfates. Once fully hardened, the Portland cement-Pozzolana blend may be stronger than Portland cement, due to its lower porosity, which also makes it more resistant to water absorption and spalling. 

Solid Content in Drilling Mud

Solid content is a fraction total solid in drilling mud, and it always increased while drilling ahead because of drilling solid (cuttings), mud chemical additives and weighting material. When we talk about the solid content, we always mean soluble and insoluble content in the drilling fluid system.

There are three types of solid contents as listed below:

- Soluble material such as salt

- Insoluble high gravity solid (HGS) as weighting agents (barite, calcium carbonate, hematite, etc.)

- Insoluble low gravity solid (LGS) or drilled solid as particles from cuttings

The drill solids are the worst content in the drilling fluid because it gradually deteriorates mud properties. Moreover, if its particle size is less than 5 microns, they could not be removed by mechanical methods, and they will stay in the mud forever. Generally, thye will take 6-7 percent of total mud volume. Since the drilled solid content is very important, it must be checked daily. For good drilling practices, the drilled solid should be tested twice a day by retorting. The upper limit of the drill solid faction should be 6-7 % by volume or approximately 55 – 60 pound per barrels. Please remember that this figure is general rule of thumb. Practically, you can operate the drilling operation with more solid content for a while but over all performance will be gradually down.

There is another value besides the LGS and HGS that you must contemplate is the average density of solids in the drilling mud. I will explain why this figure is important and what it tells us. The weighting materials as barite, Calcium Carbonate, etc have a specific gravity value about 4.2. However, the drilled solids as clay and silt have a less specific gravity about 2.6. The average density means the relative concentrations of both the weighting agent and the drilled solid. Normally, the acceptable value of the average solid density is about 3.8 or higher. If you see this value below 3.8, it indicates that there may be too much low gravity solid in the mud.

The operational impacts of solid content are as follows:

Equivalent Circulating Density (ECD) – The ECD will be higher if the solid content increases, regardless of whether High Gravity Solid (HGS) or Low Gravity Solid (LGS). As you may know, excessive ECD will lead to formation fracture and a loss circulation issue.

Differential Sticking – The filter cake can be thick and sticky, if there are a lot of low gravity solids in the drilling mud. When there is thick mud cake, you will have high potential to get differentially stuck across permeable formations.

Rate of penetration – High concentration of the solid content will affect the overall rate of penetration. As you know, there are three solid contents added into the system. The first two contents are weighting material and chemicals which we really need them in the drilling fluid. For this part, we cannot reduce their content in the mud because they are essential to for mud properties. The last one is the drill solid that we are able to control by mechanical methods. Therefore, in order to optimum ROP, you need to control the amount of drilled solid in the mud.

Surge/swab pressure – The excessive surge and swab pressures are resulted from the high amount of solid contents in the fluid system.

Pozzolanic ash, Green Binding Foundation used in Concrete and Structural Designs

Pozzolanic ash ,also known as Pozzolana is a constructive residue collected from the Biosphere system which is often used as a road base and as a material for producing concrete block for commercial uses.Hence it is also referred to as a fine volcanic ash, originally found in Italy, and there are a few sites who had done some research that showcased some varieties of pozzolana and these all can be obtained from the volcanic regions of Italy.

 

 Types of pozzolanic

  a. black 

  b.white

  c.grey

  d.red

Pozzolana is a siliceous and aluminous chemical substance which responds to calcium hydroxide in the occurrence of water in order to create compounds obtaining cementite components at room temperature and that have the capability to set under water. It transformed the chances for producing concrete structures, even though it took the Romans a while to determine its full potential.

Recent pozzolanic cements are a combination of natural pozzolans and Portland cement.The advanced alkalinity of pozzolana causes it to become more proofed against common corrosion from sulfates. Once completely solidified, the Pozzolana cement blend may perhaps be stronger than Portland cement, because of its low porosity, that also can make it more protected from water absorption and spalling.

Commercial resources of materials with Pozzolanic properties:

• Class F -fly ash from coal-fired power plants
• Silica fume from silicon production
• Rice husk ash from rice paddy-fields
• Metakaolin from oil sand operation
• Class C (calcareous) fly ash
• Ground granulated blast furnace slag 

Pozzolanic effect

Within the foundation of the Pozzolanic's kind of reaction appears to be an effective acid-base effect between calcium hydroxide also called Portlandite and silicic acid.

General formula (CaH2SiO4 • 2 H2O)

What's good about Pozzolanic ash:

• Is actually used as supplemental cementitious materials
• Many commercial and gardening by-products are pozzolanic
• Widely-used to lessen the measure of cement used within concrete

Issues Concerned

Sustainable Development aims to succeed in:

• Producing materials and products with sustainability as a primary goal
• Expanding developed products to replace less sustainable or non-renewable unprocessed trash
• Recycling suitable waste materials

Pozzolana, scoria and lava (pyroclastic material) on the external crater slope.
Avachinsky volcano (altitude - 2650 meters above sea level)

Environmental Efficiency concerns:

• Reducing green-house gases from business oriented firms and industrialized emissions
• Reducing CO2emission, which is certainly one of the primary contributors to global warming

Pozzolanic substances have long demonstrated their toughness in producing good performance concrete .This work examines the possibilities of pozzolanic ash as being a total substitution for ordinary cement. This exploration considered the appropriateness for the construction of less expensive houses and buildings.

Estimated damages of Japan Quake

Yesterday Japan said the cost of the March 11 earthquake and tsunami could hit $309 billion, double the Kobe quake and nearly four times more than Hurricane Katrina.

The total cost from collapse or damage to houses, factories and infrastructure such as roads and bridges was estimated at 16 to 25 trillion en over the next three fiscal years, the Cabinet Office said.

The estimate does not account for wider issues such as how radiation from the stricken Fukushima nuclear plant crippled by the quake will affect food and water supply, amid a deepening food scare.

Seismic Energy Dissipation Devices

Energy dissipation technology is a new technology to improve earthquake resistance of structures. During an earthquake, a certain amount of energy is transferred to the building. While buildings can dissipate, or damp, this energy, the capacity to do so before becoming deformed or damaged is quite limited.

A building dissipates energy either by undergoing large-scale movement or by sustaining increased strains in key building elements such as columns and beams. Both of these processes eventually result in some degree of damage. Structural engineers can greatly decrease the seismic energy entering the building, and thus decrease building damage, by equipping a building with additional devices that have high damping capacity.

A number of damping devices have been developed. What follows are some representative examples:

 Dampers Mechanism 

1.    Friction Dampers utilize frictional forces to dissipate energy

X - Plate Metallic Damper

2.  Metallic Dampers utilize the deformation of metal elements within the damper 

3.  Viscoelastic Dampers utilize the controlled shearing of solids

 Metallic Damper

4.  Viscous Dampers utilize the forced movement (orificing) of fluids within the damper

Fluid Viscous Dampers

Damping Device Installed with Brace

Damping devices are often installed as part of bracing systems. Figure above shows one type of damper-brace arrangement, with one end attached to a column and one end attached to a floor beam.

Response of Base Isolated Buildings

The base-isolated building retains its original, rectangular shape. The base isolated building itself escapes the deformation and damage-which implies that the inertial forces acting on the base isolated building have been reduced. Experiments and observations of base-isolated buildings in earthquakes to as little as ¼ of the acceleration of comparable fixed-base buildings.

Acceleration is decreased because the base isolation system lengthens a buildings period of vibration, the time it takes for a building to rock back and forth and then back again. And in general, structures with longer periods of vibration tend to reduce acceleration, while those with shorter periods tend to increase or amplify acceleration.

Mackay School of Mines, University of Nevada - Reno, Nevada (retrofit)

Los Angeles City Hall, California (retrofit)

Oakland City Hall, California (retrofit)

Los Angeles County Fire Command & Control Facility, California

Foothill Communities Law & Justice Center, County of San Bernardino, California

San Francisco City Hall, California (retrofit)

Enigma of Nuclear radiation of the Fukushima Daiichi plant reactors in Japan

The reactors at the Fukushima Daiichi plant are boiling water reactors. The reactor which saw the explosion is Fukushima Daiichi 1. It was connected to the grid in November 1970, making it about 40 years old. There are six reactors at the Fukushima Daiichi site, of which unit 1 is the oldest, according to the World Nuclear Association.

How does a nuclear reactor of this kind work?

Uranium 235 -- the fuel inside a nuclear reactor -- undergoes nuclear fission. This process emits a lot of heat energy which produces steam, and that steam turns a turbine, generating electricity.

What happened to the nuclear reactors during the quake?

Three of the six reactors at the site were in operation when the earthquake hit. The reactors are designed to shut down automatically when a quake strikes, and emergency diesel generators began the task of pumping water around the reactors to cool them down. However, these stopped about an hour later. The failure of the back-up generators has been blamed on tsunami flooding by the International Atomic Energy Agency (IAEA.)

Sea water injection was started on Saturday, but then paused after a tsunami warning, according to the plant owners Tokyo Electric Power Company.

What could have caused the explosion at the plant?

* Nuclear Energy

The blast was not caused by damage to the nuclear reactor but by a pumping system that failed as crews tried to bring the reactor's temperature down, Chief Cabinet Secretary Yukio Edano said Saturday. He said the plant operator confirmed there was no damage to the steel container housing the reactor.

Malcolm Grimston, Associate Fellow for Energy, Environment and Development at London's Chatham House, said he believed the explosion had been caused by a build-up of pressure inside the inner containment of the reactor.

"Because they lost power to the water cooling system, they needed to vent the pressure that building up inside.

"My suspicion is that as the temperature inside the reactor was rising, some of the metal cans that surround the fuel may have burst and at high temperature, that fuel cladding can react with water to produce zirconium oxide and hydrogen.

"That hydrogen then will be part of the gases that need to be vented. That hydrogen then mixes with the surrounding air. Hydrogen and oxygen can then recombine explosively.

"So it seems while the explosion wasn't directly connected with the nuclear processes, it was indirectly connected, because the hydrogen was only present because of what was going on in the reactor core."

What is a meltdown, and can it be avoided here?

Japan's nuclear agency said there was a strong possibility that radioactive cesium detected at the plant after the blast was from the melting of a fuel rod.

Robert Alvarez, Senior Scholar at the U.S. Institute for Policy Studies, explained that a meltdown could happen when the water surrounding the core of the reactor boiled or leaked away, leaving the fuel rods exposed, allowing temperatures to rise to up to 5,000 degrees Fahrenheit.

"The radiation is so intense it's impossible to deal with it. The control room would be uninhabitable," he said. "Without cooling, cladding surrounding the fuel can ignite, and the fuel itself start to melt.

"Then you have a huge amount of radioactive gases and particles, and if the primary and secondary containment fails, you have a large amount of radioactive gases escaping into the environment."

Whether a meltdown happens in this case depends on whether the pumping and cooling system can be restored in time, and whether if a meltdown starts, the secondary containment is strong enough to stay intact, according to Alvarez.

"If the pumping system is down there won't be enough pressure or water inside to cool the fuel rods down," he said.

Spray Foam Insulation and Winnipeg

If this same wall assembly were insulated and sealed with a  single application of spray foam insulation, the result in Winnipeg would be significantly different.  Because spray foam insulation is manufactured on site, it conforms to every minute variance, nook and cranny in the building envelope.

It is a perfect, custom made fit.  Made up of billions of tiny, microscopic bubbles, it will never settle, sag, or move, it absolutely and completely seals a wall without any penetrations.

It conforms to electrical boxes, outlets, and recessed light cans, wrapping itself around and behind them to completely enclose them.  It is inches thick and not subject to any of the potential problems of a layer only 6 mil thick. 

Spray Foam insulation is not dependent on caulking, glue or sealants to act as an air barrier or vapor barrier and results in a wall assembly that is air tight, impenetrable to moisture, and has a stable R-Value much higher than fiberglass.  At an R value of 6 per inch, there is potentially R-33 available in a 2x6 cavity wall if super insulating is required.

Upper Mantle Heterogeneities of Japan

Some pieces of evidence suggesting the regional difference in seismic wave velocity and attenuation in the upper mantle beneath Japan were obtained in the 1930s (e.g., regional distribution of travel-time residuals; the absence of sScS phases near the epicenter of deep earthquakes). As early as 1918, K. Hasegawa reported that some earthquakes occurring on the Japan Sea side were felt only on the Pacific Ocean side. This strange phenomenon (abnormal distribution of seismic intensities) was studied in detail by T.

Ishikawa and others between 1926 and 1933. Katsumata (1960) remarked that the seismic waves passing through the seismogenic parts of the earth travel faster with less attenuation than the waves traveling through the aseismic parts.

Japanese Arc and the backarc Sea of Japan

In 1966, Utsu systematically studied the seismic intensity distributions for deep and shallow earthquakes around Japan and concluded that the Q contrast between deep seismic zone and the aseismic upper mantle beneath Japan reaches 10 times or more. He also obtained a 5% difference in velocities of both P and S waves. For more details on the heterogeneous structure of the island arcs of Japan, see a review paper by Utsu (1971).