new concept of hydrogen production methods

Scientists generates hydrogen as energy source from ethanol and sunlight

A team of researchers from Universitat Politecnica De Catalunya  the university of Aber deen (Scotland ) and university of Auckland ( New Zea-land ) uses ethanol and sunlight to generate hydrogen as a energy source. The result of study have been published in natural chemistry.

Jordi Llorca  director institute of energy technology and researcher  at Universitat Politecnica De  Catalunya’  Nano engineering research centre, is one of authors of study, which represents a major step towards using hydrogen as an alternative to fossil fuels. In the frame work of research, a fully scalable photo catalyst  was created that makes the hydrogen production process simpler  and cheaper as it takes place at ambient temperature and pressure.

The solid photo catalyst is placed in a container with ethanol and exposed ultra violet by agitation, stimulating the most energetic part of the solar spectrum. The devise contained a titanium dioxide semiconductor that in contact with sunlight generates electrons captured by metallic  gold nano  particles, which reacts with alcohol molecules to produce hydrogen. According to Llorca, the semiconductor’s structure and the contact with nano particles are crucial features in the design of the photo catalyst.

The amount of hydrogen and energy developed depends on the amount of catalyst used and area exposed to solar radiation. Researchers have generated up to 5 liters of hydrogen  per  kilogram of catalyst in one minute. If 9 kg of catalyst were  put in a ethanol tank and exposed to sunlight and hydrogen generated were used to power fuel cell, 3 kw of electricity would be obtained, an amount similar to that which is used in a home.

Llorca plans to design reactors with real life applications such as providing electricity to home, which he sees as an important step towards introducing hydrogen as an energy vector and gradually gaining independence from fossil fuels. One of advantages of hydrogen compared to electricity it can be stored. An Economical process based or renewable resources until now, solar generated hydrogen technique have largely relied on water. However , despite water being cheap and abundant , these  techniques  have gamer-ed   poor results and  material required is expensive. As alternative researchers suggested  using ethanol , a renewable and economical resources that is easily obtained from agriculture and forest waste ( 100 grams of glucose generates approximately 50 grams of ethanol). The photo catalyst is also much cheaper and simpler to use than materials employed in techniques with water as it uses very small gold particles a ranging in size from 2 to 12 nanometer ( 1 meter =1 Million nano metres ). The nano particles capture the free electrons generated when titanium oxide- used as a support base- comes into contact with sunlight.

During process, which is based on solar energy, the team also discovered that the size gold particles has no influence on production of hydrogen, unlike what occurs during wide spread process in which the catalyst  powder must be heated  to reaction temperature( Usually over 500 degree Celsius ) and therefore incurs an energy cost. In addition the catalyst more durable because it works at ambient temperature and pressure.

New green technology for hydrogen production

Researcher Mohamed Halabi  of Eind hoven  university of technology demonstrates a proof of a concept for new and green technology to produce high purity hydrogen from natural gas. This allows hydrogen to be produced in an elegant technique at much lower temperatures,  and without releasing carbon-dioxide into atmosphere.

Hydrogen is a valuable feed stock for petro- chemical industry and it may play a big role in the energy supply of future, as a green, non polluting and efficient energy carrier. If it is burnt, only water is formed. However , the conventional technology for hydrogen production from natural gas (steam reforming) is a high energy intensive process, operated at high processes ( up to 25 bar) and high temperature ( 850 degree Celsius ) with multistage subsequent separation and purification units. Moreover huge amount of CO2  have to be handled in post -processing steps.
T U Eind hoven has now developed  a new  and improved technology called “ Sorption enhanced catalytic reforming methane “ using novel catalyst and hydro talcite  -based sorbent  as a new system of materials. Hydrogen is produced on the active catalyst- and co generated CO2 is effectively absorbed on sorbent, hence preventing any CO2 emissions to the atmosphere.

Halabi “ direct production of high purity hydrogen and fuel conversion greater than 99.5% is exponentially achieved at low temperature range ( 450-500 degree Celsius ) and at pressure of 4.5 bar  with low level carbon dioxides impurities” less than  100 ppm.  The enormous reduction of reactor size, material loading, catalyst , sorbent ratio, and energy requirements are beneficial key factors for success of concept over conventional technologies.

Small size hydrogen generation plants for residual or industrial application operated at a relatively low pressure, of less than 4.5 bar  seems  to be feasible.

Dr. Mohamed Halabi   received PhD on May 9 ,2011 at TV End hoven based on his dissertation “ sorption enhanced catalytic reforming methane for pure hydrogen production-experimental and modeling “. He  conducted his research at the laboratory of chemical reactor engineering under supervision of prof . Jaap Schouton.

United States nuclear policy after Fukushima crises

United States nuclear policy after Fukushima nuclear crises

Brief details about  United States nuclear policy

While the U.S. has more private sector participation in the production civil nuclear power than any other nation, the government is heavily involved through safety and environmental regulations, R&D funding, and setting national energy goals .

The commitment to nuclear power as part of the U.S.’s long term energy policy strategy continuous with Obama administration, but there has been a reduction in some nuclear programs as result of greater emphasis on alternative source.

This disposal and storage high level waste remain a major un resolved issue. The government remains more involved in commercial nuclear power than any other industry in U.S. There are lengthy detailed requirements for construction and operation of all reactors and conversion, enrichment, full fabrication. Mining and milling operations. The review process preceding the construction of new reactors can take 3-5 years. The U.S. government, though its own research  laboratories and projects at university and industrial facilities is main source of funding for advanced reactor and fuel cycle research. It also to provide incentives for building new plants through loan guarantees and tax credits, although owners have to raise their own capital. U.S. domestic energy policy is also closely linked to foreign, trade and defense policy on such matters as mitigating climate change and nuclear non-proliferation (of weapons).

As on January 2010 the nuclear regulatory commission (NRC) was reviewing 13 applications for combined construction and operating licenses( COLs)  to build 22 new reactors as well as for application for design certification for reactors.

State and local governments  also have a major impact on frame work and economics of nuclear power industries . De regulation  of electricity prices in some states in 1990 led greater concentration.

In February 2002, DOE announced nuclear power 2010 program a government industry, cost shared partnership to spur new construction of advanced current generation ( generation 111)  plants. The program provided matching funds for preparation of license application and encouraged the industry to make use  expedited licensing procedures, such as combined and construction and operating license(COL) process in seeking approvals from NRC. This initiative led to formation several utility consortia , formed to put together  proposals to receive matching funds for advanced plant application under COL process.

The Obama  administration FY 2010 budget request drastically reduced funding for nuclear power 2010 program with only 20 million dollars requested fiscal year versus 177.5 million dollars fiscal 2009. The budget cut brought U.S. congress which has final word on appropriations  allotted 105 million dollars FY 2010.

While the broad out lines of U.S. nuclear policy on matter such as energy independence and controlling carbon emissions remains same as each new administration brings shift in policy.


U.S. nuclear policy after Fukhushima  nuclear crises.

On March 11, 2011 a magnitude of earthquake and subsequent tsunami  hit Japan severely damaging cooling systems at Fukhushima nuclear reactors. Radiation leaks have led to an evacuation zone, a no-go area and traces radiation reaching east coast of U.S. The facts and developments reported in media continue to change until full scope and latest information of Fukhushima nuclear crises understood, it will be unclear which lessons the U.S.should learn from this nuclear disaster. In mean time there is issue of disposal of nuclear waste.

As  Japanese authorities continue their efforts to get back the nuclear reactors Fukhusima  Daiichi, questions are being raised the future of nuclear energy in United States. Making broad policy decision before Fakhushuma crises is fully analyzed risks enacting reforms that do advance safety and create unnecessary  barriers or creating hurdles to American nuclear power.

Only two months after earthquake  and tsunami, facts are changing and information difficult to verify. U.S.authorities  don’t have necessary technical data how calamity happened in Japan to reform American nuclear industry.

The U.S. has an effective multifaceted regulatory regime that had already addressed many of mistakes and difficult situations that Fukushima seem to have exposed including earthquake and tsunami preparedness and necessary modifications to aged reactors to meet new evolving safety guide lines. On the other hand the accident should raise objections about  America’ s lack of nuclear waste disposal plan.

Earthquakes and tsunamis

While building nuclear reactor that withstand earthquake and tsunami is a new issue to Americans, but U.S.nuclear industry and NRC have enough geological data to face such nuclear crises.

U.S. nuclear regulatory commission mandate that  the most powerful earthquakes ever  recorded for their nuclear plant sites but also withstand most powerful earthquake that geologists think possible for each site.

Current Fukushima earthquake and tsunami under the strict scrutiny and NRC may issue new guide lines in due course.

Further policy makers must recognize reactors owners are highly motivated to maintain safety precautions better preparedness to ensure public safety. Under current U.S. policy the plant operators set to enforce high safety standards - and allow nuclear reactor owner to decide and take necessary steps to avoid radiation leakage and how best to meet them. 

The Mark 1 containment

According to the nuclear energy institute 23 U.S. boiling water reactors share same basic  containment design the Mark 1, as the Fukushima reactors in Japan. The history of Mark 1 containment design in the U.S. is a testament to the effectiveness of American system of nuclear regulation for maintaining public health and safety problems,

The industry responded by forming a Mark 1 reactor owner group to determine how to change the design to address safety concerns, the plants were modified accordingly.

To supply off-site power and water to reactors and fuel pool have been developed in the event of on site power is lost. Hardened containment venting has been added to every plant to ensure that pressure can be safely released from containment should there be system break down.

Nuclear fuel

The problem with spent fuel pools at Fukhushima  high light one area where  policy need reviewed and up dated. Japan in sufficiently prepared to respond to loss of water in the used fuel pools. The loss of water allowed some of used fuel rods to be exposed which resulted increase in radio active releases and additional problems to plant operators. While actual causes may be known later, it seems some water may have been lost during earthquake and that pool integrity was likely compromised during hydrogen explosions. Radiation then spiked as a result of rods being exposed, making emergency response very difficult.

It is unlikely that such a chain events could occur  in U.S. nuclear power plants due to action taken after post 9/11, the U.S. nuclear industry has carried out additional safety precautions against explosions and accidental fires.

In Japan, France or U.S. used fuel is removed from reactors once in 18 to 24 months. Once the fuel is removed it is placed into used fuel pools for further cooling. After 5 years most advanced nuclear nations reprocess fuel again , whereas the 1982 U.S. policy act as amended, mandates that federal government dispose of commercial nuclear waste by placing it in respiratory at Yucca Mountain , Nevada. But federal government defaulted their regulation. The Obama administration exacerbated the situation by attempting to Yucca program without proposing any alternatives to dispose plan for used fuel.

Result U.S. power plants are being forced to collect most spent fuel in pools than they were ever engineered to hold. The federal  regulators at NRC license commercial nuclear facilities and operators , develop regulations, and provide over sight and enforcement of these regulations. This process is supplemented by private regulation. After Three Mile Island accident, the nuclear industry created the institute  for nuclear power operations (INPO) a non-profit, independent private organization that promotes safety and reliability at nuclear power plants. INPO also provides technical and management assistance nuclear industry.

It is suggested president and congress insist NRC finish and review to construct and operate used fuel repository at Yucca Mountain.

Lessons have already emerged  from Fukhushima that can help guide U.S. policy makers clearly Americas approach to nuclear waste management. Simultaneously an early comparison of U.S. and Japanese approaches to safety at commercial nuclear power plants will give better  picture about the nuclear industry in U.S and its policy.  

Japan 9.0 Tohoku-Oki earthquake and surprising findings

Japan 9.0 Tohoku -Oki Earthquake Surprising findings about energy distribution over fault slip and stress accumulation- nuclear energy

When the magnitude 9.0 Tohoku-Oki earth quake and resulting tsunami struck off north east coast of Japan on March 11, they caused wide spread destruction and death. Using observations from dense regional geodetic net work ( allowing measurements of earth movements to be gathered from GPS satellite data) globally distributed broad bank seismographic net work, and open ocean tsunamic  data, researchers have begun to construct numerous models that describe how earth moved that day.

Now a study led by researchers at California institute of technology ( Caltech) published on line in May 19 issue of science express, explains the first large set of observational data from this rare mega thrust event.

“ this  event is best recorded great earthquake over “ says Mark Simon professor of geophysics at Caltech’s seismological laboratory and lead author of study. For scientists  working  to improve infrastructure and prevent loss of life through better application of seismological data, observations from event will help inform future research priorities.

Simons  says one of most interesting findings of data analysis was spatial compactness of the event. The mega thrust  earth quake occurred at subduction  zone where pacific plates dips below Japan. The length of fault that experienced significant slip during the Tohoku earthquake was about 250 kilometers about half what would be conventionally expected for an event of this magnitude.

Future more, the area where fault slipped the most- 30 meters or more -happened within 50-60 kilometer long segment. “ This is not some thing we have documented before “ says Simons.

“I am sure it has happened in the past, but technology has advanced only past 10 to 15 years to the point where we can measure these slips much more accelerately  through GPS and other data.”

For Jean Paul Ampuero assistant professor of seismology at Caltech’s seismological laboratory who studies earthquake dynamics, the most significant finding was that high-and low frequency seismic waves can come different areas of fault. “The high frequency seismic waves in the Tohoku earth quake were generated much closer to coast away from area of the slip where we saw low frequency waves. “ he says. Simons says there are two factors controlling behavior : one is because the larger amount of stress ( which is what generates high frequency waves ) was found at edges of slip not near centre of where fault began to break. He compares to finding to what happens when rip of piece of paper in half. “ The highest  amount of stress are not found where paper has not been torn” he explains. “ We  had previously thought high frequency energy was an indicator of fault slippage , but it did not correlate in our models of this event . “

Equally important is how the fault reacts to these stress concentrations it appears that only deeper, segments of fault respond to these stresses by producing high frequency energy.

Ampuero says the implications of these observation of mechanical properties of tectonic faults need to be further explored and integrated in physical models of earthquake,  which will help scientists better quantify earthquake hazards.

“ We learn from each significant earth quake, especially if earthquake is large and recorded by sensors” says Ampuero. “The Tohoku earthquake was recorded by up words of 10 times more sensors at near fault distances than any other earthquake. This provide a sharper and robust view of earthquake rupture processes and their effects.”

For seismologist Hiro  Kanamori Cal techs professor of Geo-physics, Emeritus who was in Japan at the time of earthquake and has been studying the region many years, the most significant finding was that large slip occurred near Japan trench. While smaller earthquakes have happened in the area, it was believed that relatively soft material of sea floor would not support large amount of stress. “ The amount of strain associated with large displacement is nearly 5 to 10 times larger than we normally see in large mega thrust earth quakes “ he notes. “It has been generally thought that rocks near Japan trench could not accommodate such large elastic strain.”

The researchers are still unsure why such a large strain was able to accumulate in this a  area. One possibility is that either the sub ducting sea floor or upper plate or (both)have some unusual such as regions that were formerly under water mountain ranges on the pacific plate-that have now been consumed by subduction zone and cause the plates to get stuck and build up stress.

“ Because of this local strengthening - what ever its cause- the pacific plate and Okhotsk plate had been pinned together for long time, probably 500 to 1000 years and finally failed this magnitude 9.0 event. Says Kanamori. “ Hopefully , detailed geophysical studies of sea floor structure will eventually clarify the mechanism of local strengthening in this area. “

Somans says researchers knew very little about area where earthquake occurred because of limited historical data.

Instead of saying large earth quake probably would not happen there, we should have said that we did not know” he says. Similarly he says the area just south of where fault slipped is similar position, researchers don’t  yet know what might do in the future.

“It is important to note that we are not in predicting an earthquake here “ emphasizes Simons  . “ However we don’t have data on the area, and therefore should focus attention there, given its proximity to Tokyo.”

He says that the relatively new Japan’s seafloor observation systems will prove very useful in scientists attempt to learn more about area.

“Our  study is first foray into what is an enormous quantity of available data “ says Simon s. “ there will be lot more information coming out this event, all which will help us to learn more in order to help inform infrastructure  and safety procedures.”

The work was funded by the Gordon and Betty Moose Foundation, national science foundation grants; the southern California earthquake centre and NASA international research and technology development program.

Effect of massive earthquake on nuclear energy

The observation data from this rare mega thrust earth quake which was lot of bearing on nuclear plants situated Fukushima Daiichi in Japan. The event that occurred is best recorded great earthquake over . Present observations will help avoiding loss of life and destruction and nuclear radiation leakage through better application with seismic data available and also for future conclusion in designing new nuclear reactors.

The technology has developed and advanced last 15 years though we now to  take care such mega thrust earth quake which can prevent  mass damage and develop latest safety technology available to take care precautions to nuclear reactors in event of disaster   . Researchers knew very little about area where earthquake occurred because of limited historical data. Now data is available for scientists and nuclear engineers to develop safety techniques for nuclear reactors in the event of core melting. 

Hence nuclear scientists and engineers to develop and design latest 111 stage nuclear reactors that can with standard massive earthquakes instead of finding faults on nuclear energy which is a safe and clean source energy. Such type of earthquake normally may occur  rare or once thousand years or so. Because of  such disaster we cannot run away and post phone our nuclear program since which  is  safely proved tested technologically developed  energy .      .

ecomic situation in india

India economic situation in India.

India’s growth and economic situation improved due to increased industrial activity ( increased exports ) and bumper agriculture production during last one year.

India’s  foreign exchange reserves are 305, 477 million dollars as on 31.03.2011 as compared to China’s foreign exchange reserves 2,622,000 million dollars as December 2010 and United States foreign exchange reserves 142,925 million dollars as on April 2011.

The strategy to be followed to  promote export policy and to improve balance payment situation. India’s more imports, higher growth of G.D. P., the performance in industrial sectors seems to be clear bearing on imports. Grater industrial activity is seen to be associated with high growth in imports in country.

India’s industrial out put registered a sharp rise in March beating analysis estimates and alloying for more concern  of growth. Exports also maintained the growth tempo surging more than expected.

Factory out put as measured by index of industrial production (IIP) rose 7.3 per cent in March from year earlier almost double the revised 3.7 per cent expansion in February according to data.

Economists cautioned that  growth at best would remain at this level in near future because of rising borrowing costs would dampen demand.

“ We remain hesitant in accepting current industrial print  as sign of consistent strength in near future “ a financial analyst said. Improved growth in manufacturing sector in March is more an indicator of continued volatility in growth sector for last few months .” another financial analyst said.

Capital goods out put recovered in March  after contracting  for three straight months rising an annual  12.9 per cent. But experts said reading should not be interpreted as rise in investments.  “ the face and extent of investment pull up seems over stated “ said Deepali Bhargva chief economist with ING Vysya Bank. She attributed the revival in production capital goods to “ lax growth in first half year which needed to be made up in last quarter.

Amidst the middle east turmoil and series of natural disasters in Japan, India has still managed to perform fairing well at export front.

In 2010-2011 India’s exports went up by 37.5 percent which is fastest growth they have seen since they gained their independence from U.K. in 1947. Due to nations efforts to diversify their markets and increase trade within its region it shipped 245.9 billion dollars goods to other countries. This number went beyond the government  initial goal for year 200 billion dollars. With the strength of past year behind then government set an even higher goals of 450 billion  dollars for 2013-2014 which will be rise 25 % rise in export. In March alone the nation set out 29.I billion dollars worth goods which is highest amount for any single month performance. This is a great news for India after their exports fell by 3.5 % in 2009-2010 because of international financial crises.

Globalization of Indian economy

The process of globalization of Indian economy is irreversible and opening  of India economy has to be managed in a manner so as to derive maximum benefits from world markets. The process should be to strengthen the potential Indian industry to compete efficiently in world markets.

In this context it is suggested there is need to bring about a phased reduction in import tariff to bring them in line with developing countries so that our industry more competitive on world markets. It is further suggested that this with realistic market determined exchange could be helpful in reducing cost of production and give incentive to modernize industry. Simultaneously steps will have to be taken to strengthen  the anti dumping machinery to ensure that domestic industry is not subject to unfair competition.
 It is obvious from above that maintenance of balance payments stability is paramount important that  and this will require achieving high rates of export growth. Exchange rate is one important determinant  of export performance and it is essential to ensure that exchange rate remains supportive of export effort and development process simultaneously.

RBI pegged gross domestic growth (G.D.P. ) at 8 per cent for current financial year- lower than government projection of 9 per cent “ perhaps the threshold for inflation is 5%” RBI Governor Subbara Rao said.

India priority sector for public and private partnership

In the budget 2011-2012 finance minister Pranab  Mukherji had announced setting up the funds through special purpose vehicles for attracting foreign investment in infrastructure sector “ to attract foreign funds for financing of infrastructure, I propose to create special vehicles in the form of notified infrastructure funds

The plan is to invest 1 trillion dollars in ports, highways, power utilities and telecoms infrastructure in next five years. A comprehensive policy frame work for public private partnership in building of physical infrastructure and social sections such as health and education is also on the anvil. Mukherji said “ I will lay down guide lines for entry of private players and implementation of infrastructure projects. 

The union budget 2011-12 has given major attention to infrastructure and real estate sector. Finance minister is giving due important to the second largest employment generating sector of Indian economy real estate  sector. The market has welcomed the reduction of fiscal deficit target. For  the real estate sector  & infra sector, there are six major factors.

1. Priority of house loan limit raised.
This will certainly help the lower income group of buyers who plan to buy a home through bank loans. As last budget it was directed that every bank has to maintain 20%  of the loans to this priority sector, this is definitely a boost for sector as it will increase demand.
2. Interest subvention of 1 per cent on housing loans raised to 15 lakhs
Interest subvention is basically an interest subsidy given by government on loans. Here subsidy of 1%  for loans up to 15 lakhs on housing costing not more than 25 lakhs is definitely a giant leap so as to boost the demand for affordable housing.

Allocation of 58,000 crores   to Bharat Nirman  projects

This is a very good move by union government towards rural development of our country. As the project also for employment generation includes development of rural housing, this allocation is going to help developers in developing quality housing projects in rural parts of India.

Creation of infra debt fund to boost infra funding
It has become a very tough task to get loan from banks for infrastructure projects. Also after latest scams, banks are now reluctant to lend this sectors. This infrastructure debt fund will certainly ease entire procedure and will help us securing regular inflow of funds for our on going new projects. Plan to allow limit infra bonds up to 25 billion dollars for entire infrastructure sector, I think this is the most important step taken by honorable finance minister. This will solve the funding problem on the entire sector up to great extent.

India’ s defense expenditure

India plans to reduce defense import bill from present 40,000 crores (8.938 billion dollars) to 20,000 crores (4.69 billion dollars) minister for defense M.M. Pallam Raju  said recently. Presently the defense import bill constitutes around 65 per cent of total defense budget. The total budget for defense is around 6o,ooo crores (  13.4 billion dollars). Of this we import 60 to 65 percent equipment and 35 to 40 percent is made indigenous only. The ground is being created to reverse the percentage over a period. This is not possible to achieve through PSU though we need private sector to achieve this. 

During 2012-2017 five year plan India aim to generate 100,000 MW of electricity from all energy sources including nuclear power.

No doubt that creation infrastructure debt fund and investing ports , high ways, power utilities including high voltage transmission lines and telecoms infrastructure in next five years will generate employment and improve foreign investment in India.

But India’s challenging problem for government is poverty, and creation of employment  to educated youth including providing employment to uneducated agriculture lab our. However national rural employment scheme of Government of India providing work for agriculture lab-our though its benefits are not visible.

Government should invest in the following sector to improve economic conditions of people in India and this improve India’s  growth .

. Provision of liberalized loans and development of small scale industries in rural areas like China which investing heavily on small scale industries for growth of country.

. Technology development and assisting qualified engineers to explore research and development for catering necessary engineering equipment and machinery spares to defense as a import substitution as this sector is not received enough encouragement from government of India.

. It is essential government to improve  and invest massive capital for building adequate railway lines which improve travel and moment of goods and also help creation employment for educated youth.

Government should invest on job oriented technical education  which will reduce un employment.

Government should take loans from world bank and Asian development bank for improving agriculture yields by research and development to increase agriculture production and good agriculture practices overall to reduce cost of food which will benefit poor..

new storage proposal for U.S. nuclear waste

New storage  proposal for U.S. Nuclear source to be unpopular

No U.S. politician ever lost an election by opposing a nuclear waste dump. That’s  why the latest report on from U.S. department of energy commission will end up in the same garbage can as proposal to build a nuclear  waste dump at Yucca Mountain in Nevada.

The latest idea is build one or more above ground storage facilities made of enough concrete and steel to resist a potential terrorist attack and to store the spent fuel supply for decades. Courts have ruled out the law establishing Yucca Mountain requires the DOE to show that spent fuel could be safely  stored there for a million years. The best the department could do was 10,000 years. A million years then 10,000 years  now about 120 years. What happens after that is anybody’s guess and somebody elses problem.

The political beauty of this solution is that it kicks the can down road a really long ways. It also prevents the DOE and congress from having to consider doing things differently.

In U.S. virtually all spent nuclear fuel is stored in casks above ground out or cooling ponds located at the reactor sites. There are 104 operating reactors in U.S. and more than 100 disposal sites. The cooling ponds are similar to the ponds that began leaking and then over heating at Fukushima Daiichi reactors.

France which generates about 80 % of its electricity from nuclear power, and the Japan and U.K. all recycle and reprocess most of their spent fuel. Reprocessing is not illegal in U.S.,but there is no nuclear  reprocessing plant in the U.S. but it was deemed and cleaner years ago to use only new fuel rods in the U.S.  reactors. It is probably still cheaper to use new uranium.

A nuclear reactor design could also make Terra Power LLC is working on traveling wave reactor that could use a small amount of low-enriched uranium to start up and then fuelled with depleted uranium, which is a by product of standard enrichment process. This company claims its reactors could run for decade on depleted  uranium, reducing dramatically the amount of nuclear waste.

There are about 700,000 metric tons of this low -level nuclear material lying around U.S. and Terra Power claims that mere 8 metric ton could generate 25 million megawatts annually. The company’s  original backers included Bill Gates and Nathan Myhrvold  of Micro Soft and now include venture capitalist Vinod  Khosla  a founder of Sun Micro Systems and driving force behind Kir Inc - bio fuel company that recently filed for an I.P.O.

Any of these solution, though will take time. Even if Yucca Mountain had been approved construction would have taken about 10 years. Building above ground storage as the DOE commission recommends, would take about long. So would designing and building Terra power reactor with commercial development 15 years off.

In wake of disaster in Japan, no plan to do any thing about nuclear power in the U.S. is likely find support. If any thing  most of support will be shutting the existing power plants down as their licenses expire. How U.S. will replace that approximately 20 per cent of total U.S. generation is an unanswered question. Solar or wind or geo thermal or something else or all combined not likely to meet  demand.

The answer is to develop latest nuclear reactors with  safety parameters and continue to educate operators and technicians on latest safety guide lines while operating nuclear reactors and  it is  advised to U.S. for investing heavily  on safe latest nuclear technology  instead of running away from global proved and reliable accepted  nuclear technology.
  

china nuclear power

China nuclear power

China has 13 nuclear reactors in operation, more than 25 under construction and more about to start  construction soon. Additional reactors planned including some of world’s most advanced to give more than ten fold increasing in nuclear capacity at least 8o Gwe  by 2020, 200 Gwe by 2030 and 400 Gwe  by 2050.

Most of mainland’s  china electricity is produced from fossil fuels ( 80 percent from coal ) 2 % from oil 1 % from gas in 2006) and hydro power 15 %. Two large Hydro projects are recent additions. Three Gorges of 18.2 Gwe  and yellow River of 15.8 Gwe . Rapid growth in demand has given rise to power shortages , and reliance on fossil fuel has led to much air pollution. The economic loss due to pollution is put up by world bank at almost 6% of G.D.P.

Chinas domestic electricity production in 2009 was 3643 billion Kwh , 6 % higher than the 3450 billion Kwh  in 2008, which was 5.8 %  more than 2007 ( 3260 billion Kwh )

Installed generating capacity had grown by end of 2010 to 962 Gwe, up 10 % on previous years 874 Gwe which was 10.2 % above 2008 figure of 793 Gwe . At the end of 2010( fossil fuelled  capacity mostly coal reached 707 Gwe , and hydro capacity was 213 Gwe  and wind capacity reached 31GWe . Mean while investment in electricity dropped 8.5 % CNY 705 billion ( 107 billion dollars ) for the year. Capacity growth is expected to slow reaching about 1600 Gwe in 2020. 

These capacity increase figures are all  the more remarkable considering the forced retired of small inefficient coal fired plants ; 26 Gwe of there was closed in 2009 and 11 Gwe in 2010, making 71 Gwe  closed since 2006, cutting annual coal consumption by about 82 million tonnes and annual carbon dioxide emissions by some by some 165 million tons. China was well advanced in developing and deploying super critical and ultra super critical coal plants, as well as moving quickly to design and deploy technology for integrated (coal gasification combined cycle(IGCC) plants.

Due to increasing concern about quality of air and global warming nuclear power has been looked an alternative to coal power in china . China has two major nuclear power companies China national power corporation operating north east China and China Guangdong nuclear power group operating mainly in south east China. The people’s Republic of China is also involved in development of nuclear fission reactors though its participation in ITER project, having construction an experimental nuclear fission reactors as EAST located in Hefei, well as research and development into thorium fuel cycle as potential alternative means of nuclear fission.

Nuclear  power in china has important role, especially in coastal areas remote from coal fields and where the economy is developing rapidly. Generally nuclear plants can be built close to cent re demand, whereas suitable wind and hydro sites are remote from demand. Move to build nuclear power plants commenced in 1970 and about 2005 the industry moved to rapid development stage. Technology has been drawn from France, Canada and Russia  with local development based largely on the French element. The latest technology acquisition from U.S. ( VIA Westinghouse owned by Japan’s  Toshiba) and France. The Westinghouse AP 1000 is main basis of technology development in immediate future. 

During nuclear emergencies at Japan’s Fukushima nuclear power plant, China announced on 16th March 2011 that all nuclear power plant approvals were being frozen and that full safety check of existing reactors would be made. Although Zhang Li-jun vice minister  of environmental protection has indicated that china’s overall nuclear energy strategy would continue. Some commentators have suggested that additional safety related costs and public opinion could cause a rethink in favor of an expandable renewable energy program. In April  2011 CHINA daily reported that approvals for construction of nuclear power plants in marine areas have been suspended. 

Most nuclear power plants in china are located on the coast generally use sea water  for  cooling direct  once through cycle. New York Times has reported  that china is placing many of nuclear power plants near large cities and there is concern that  ten of millions of people could be exposed to radiation in the event of accident. China neighboring Guadong and Lingao nuclear power plants have around  28 million people within a 75 kilometer radius that covers Hong Kong.

Following  the Fukushima accident in March 2011 the state council announced on March 16 that it would suspend approvals for new nuclear power stations and conduct comprehensive safety checks of all nuclear projects including those under construction. About  34 reactors were already approved by central government  which 26 were being built. The Shidaowan HTR  though ready for first concrete was also differed.

Prior to 2008, the government planned to increase nuclear generating capacity to 40 GWe  by 2020( out of which total 1000 Gwe planned) with further 18GWe nuclear being under construction. However governments targets for nuclear power have been increasing. As of June 2010 official nuclear installed capacity projections were 70-80 Gwe by 2020, 200 Gwe by 2030 and  400-500 Gwe by 2050. China Daily in January 2011 quoted as senior official projecting 86 Gwe target by 2020.

In September 2010 China daily reported that China national power corporation (CNNC) alone plan to invest CNY 800 BILLION ( 120 Billion dollars) into nuclear energy projects by 2020. Total investment in nuclear power projects, in which CNNC will hold controlling stakes will reach CNY 500 BILLION ( 75 billion dollars by 2015, resulting in 40 Gwe on line according to CNNC. In order to fund company expansion project CNNC plans to list its subsidiary CNNC Nuclear Power Company limited in 2011 to attract strategy investors.

In January 2011 a report from state council research office ( SCRO) which makes independent policy recommendation to state council on strategic matters was published. While approving the enormous  progress made on many fronts, it cautioned concerning provincial  and corporate enthusiasm for nuclear power projects and said that the 2020 target to be restricted to 70 Gwe of new plants actually operating so as to avoid placing undue demand on quality issues in the supply chain. Another 30GWe could be under construction. It is emphasized that the priority need to be resolutely on generation 111 technology notably AP 1000 and derivatives. However ambitious status target to deploy AP 1000s with reduced foreign input had proved difficult and as a result more of generation 11 , CPR-1000 units are under construction or in order. Only china is building generation=11 units to day in such large numbers with 57 ( 53.14 Gwe ) on books.

SCRO said that reactors built today should operate for 50 to 60 years meaning on large fleet of Gen-11 UNITS still be in operation in the 2070s , when even Gen-111 reactors would have given way to Gen-1v  and perhaps even to commercial nuclear fission. The country should not be too large to avoid any perception of being below international standards of safety future, when most of worlds  Gen-11 reactors are retired. The SCRO noted the  100 fold increase  in probabilistic safety brought Gen-111 and that future generations would continue trend.

Energy hungry developing countries such as China and India , Mexico and Iran are moving forward on plans to build more nuclear power plants, even authorities around the world intensify safe inspection of existing plants after Japan’s  March 11 disaster.

Initial fears that erupted in the wake of crises, threatening to derail the nuclear renaissance of last several years have largely subsided. Many of the 30 plus countries with nuclear energy program continue to promote them as way to combat pollution and global warming-despite radiation risks and questions on what to do with nuclear waste.

India which has also stepped up safely measures is championing nuclear power as a clean and environmentally friendly alternative to polluting coal-fired power plants. It is aim to increase the share of nuclear energy from 3 per cent to 13 percent by 2030.   

global warming and nuclear energy

Global warming and nuclear energy

Current energy polices , if left as they are together with strong growth in energy demand would have disastrous impacts on climate since, according to 1EA,they would be accompanied by 50%  increase in green house gas emissions from energy sector by 2030, recognizing that sector accounts for two-third of total emissions today. The inter government panel on climate change (IPCC) considers that such an increase would trigger a global rise in temperature from 2 degree Celsius to 4 degree Celsius . According to the Stern  report, the cost of inaction in the face of situation could account for an minimum of  5 % of worlds gross domestic product (GDP) or even 20 % in more pessimistic scenario, while emissions reductions would cost only 1 % of world G.D.P.

This as part of its climate and energy package Europe has  set  a goal of cutting emissions by 20 % by 2020, compared with a 1990 baseline.

In 2005, European union set up a system to capture CO2 emissions by establishing the European trading system which recognizes the economic value of emission reduction.

Federal laws in United States such as energy independence and security act, the energy improvement and extension act and American recovery and reinvestment act, provide  financial support to companies that invest in carbon free energy sector or local resources of energy with added value. Three voluntary carbon emission permits trading exchanges- the regional green house gas initiative, the Midwestern green house gas accord and western climate initiative-are being established in 55 states and provinces in the Unites States, Mexico and Canada.

China , India and other emerging countries are also becoming key players in climate change fight. Their recent commitments to growth with less fossil energy are indicative of new understanding of risks associated with growing emissions.

China in particular announced its decision to invest 738  billion dollars in carbon free energies over 2011-2020 period. It has set up seven pilot carbon credit exchanges in Beijing,Shanghai , Tianjin, Wuhan, Kunming,Changsna  and Shenzhen and is perusing a 40% reduction in carbon intensity by 2020 compared with 2005. India launched an ambitious program to develop solar and nuclear energy with goal of 40 GW of new capacity in service by 2020, together with 20 % reduction in carbon intensity by 2020 compared with 2005. Several countries in Africa and  Middle East  have set up similar goals.

Today power generation accounts for 41 % of GHG emissions from energy sector ahead of transportation (23 %) and manufacturing (17% ) and potential for emission reduction is greater there. It is therefore vital to seek carbon-light energy mix which means developing renewable energies and nuclear power.

Anticipating depletion of fossil energy resources

The gradual depletion of hydro carbon resources is a major threat to global energy supply. According to the IEA new policies scenario, conventional oil production peak in 2006 and average price per barrel of oil reached 113 dollar by 2011 it self.

It is true, however that “peak oil” the actual level of hydro carbon reserves and future prices for hydro carbon are not in concrete. That is why it is important to start thinking about what  a “ post -petroleum “ society might look like, to ensure energy self-sufficiency  among nations and avoid the consequences of the evitable rise and volatility of oil or gas prices if demand were to increase too much.

“ We should leave oil before oil leave us “ is the Leit motif of Faith Birol  chief economist of IEA.





Investing to improve global power generation mix

Massive capital spending in the electricity sector and radical change in power  generation mix are required for reason out lined above. Rising demand for electricity, urgent effort to prevent climate change and declining fossil resources.

The IEA s world energy out look 2010 includes a new polices scenario that takes into consideration firm or planned policy commitments in countries around globe. The central scenario measures the impacts of then decisions on the energy sector,  compared with two scenarios used previously “ current polices scenario “  which assumes no major change in energy policy compared with situation at mid 2010 the scenario designed to limit concentration of green house gases in the atmosphere to 450 ppm (in CO2 equivalent ) thereby limiting the temperature increase on planet  to 2 degree Celsius .

Nuclear generating capacity would climb 80 % by 2035 in central scenario, when a significant share of existing reactor fleet would have to be replaced.

Nuclear power solutions for global energy challenges.

Nuclear power offers many advantages on the environmental, economic, strategic and operational levels.

. It help combat climate change
. It creates significant value locally and creates a large number of highly qualified jobs that  cannot be delocalized.
. It is cost competitive compared with other sources of base load electricity.
. It provides excellent  return on investment and limit electric rate hikes for consumer in times of sharply rising oil gas prices.
. It offers stable production cost with less uncertainty concerning electric rates.
. It consumes security of supply : nuclear fuel is easy to store and uranium resources are well distributed around globe, unlike oil & gas reserves, which are concentrated in Russia  and Middle east with Russia , Qatar, Saudi Arabia and Iran contributing more than two-thirds of worlds oil and gas reserves and
. Its offers heightened operational safety  performance particularity with new 111+ reactors developed by Areva including “ EPR “ reactor the Kerena reactor and ATMEA1 reactor.

Nuclear power is competitive

The correlation between nuclear engineering costs and price of uranium is very low now. The contribution of raw materials to the total cost of nuclear power (at present value ) is minimal and impact a doubling of uranium prices on the full cost of power generation in new power plants is only 5 % .

Conversely, the cost of fossil energies has very strong impact on the cost of electricity generated in thermal power plants fueled with coal, and the situation is even worse for gas. The price of carbon is important component in the cost structure of gas fired power plants, and even more so, for coal based fired plants but it has zero impact on the cost of nuclear power.

 Gas and oil prices reached historic levels and then fell shapely in 2010. Today trend is up again. Prices have not returned to 2008 levels yet because  of slow and uncertain economic recovery, but the consensus is that trend will rise in medium term due to increase in demand and shift from coal to natural gas and deletion of conventional resources.

Coal resources are more plentiful than those of oil and gas but demand for coal is also rising more sharply. Moreover the international trading in coal represents an increase in share of global consumption, illustrated growing dependency of some countries and pushing shipping costs as well. Coal prices have risen due to increased demand in Asia (China and India ) combined with export restrictions in certain producing countries (Indonesia and Vietnam) and spike in maritime freight costs. The price has remained same level 100 Euros per metric ton since October 2010. The global coal price will be driven by long term demand in Asia but also but also by the predictable drop in Australia production in 2011 in aftermath of catastrophic flooding in that country.

Carbon prices remained relatively stable in Europe in 2010, although generally higher than 2009. Increasing stringent commitments in terms of emission reduction will necessarily push carbon prices in countries where regulated carbon market has already been established while other countries ( developing countries, U.S. etc) carbon restrictions seem un avoidable in medium to long term.

The cost of gas or coal based electricity is difficult to predict, considering the historical volatility of commodity prices and uncertainty surrounding the price of carbon.

Another major advantage of nuclear power is security of supply it promises. Unlike  hydro carbon reserves which are concentrated in certain regions, uranium resources are found in OECD countries ( 39%) major emerging countries such as Brazil, Russia , India , china  and South Africa (26% ) and other part of world  ( 35% ).

Nuclear power offers enhanced safety and operating performance with latest generations of reactors.

Areva range of reactors offers a combination of capacities from 1000MWe to 1650 Mwe  and technologies suitable for each type of customer including pressurized water or boiling water reactors. These reactors also meet the most recent requirements in terms of nuclear safety, 

Nuclear safety
Designs  that drastically reduce the possibility of a serious accident and ensure that there would be no off site consequences ( core catcher  to confine the molten core, double containment building ability to with stand a large commercial air craft crash)

Competitiveness : reduction in fuel consumption and operation costs high availability  ( 92 %) over a 60 year operating life this maximizing power generation.

Environmental protection : reduction in the quality of fuel used and final waste.

After Fukushima nuclear accident in  Japan serious doubts in Asian countries initially about safety of   reactors after  several clarifications from nuclear scientists and engineers nuclear industry set to regain its importance . India has announced it go ahead implementing Jaithapur nuclear project with clear indication that nuclear power  is safe and clean energy.

off shore wind technology trends and economics

Off-shore wind technology trends  and economics

In common with other clean, renewable, domestic sources of energy, off shore wind power can help to build a diversified and geographically distributed coastal countries energy mix offering security against many energy supplies whether natural or man-made. Wind power also emits no carbon dioxide (CO2) or other harmful emissions that contribute to climate change, ground level pollution or public health uses.

Off-shore wind energy resources can significantly increase the wind industry contribution to the coastal countries clean energy portfolio.

The U.S. ,Europe and Asian countries are fortunate to posses a large assessable off-shore wind energy resources. Wind speeds tend to increase significantly with distance from land, so off-shore wind resources can generate more electricity than wind resources at adjacent land based -sites.

Off-shore wind technology status

Although Europe now has a decade of experience with off-shore wind projects in shallow water, technology  essentially evolved from land based wind energy systems. Significant opportunities remain for tailoring the technology to better address key differences in the off shore environment. These opportunities are multiplied when deep water floating system technology is considered which is now in the early stages of development.

The opportunities for advancing off shore wind technologies are accompanied by significant challenges. Turbine blades can be much longer without land based transportation and construction constraints,  however  enabling technology is needed to allow construction of blade greater than 70 meters in length. The blades may also allowed to rotate faster off shore, as blades noise is less likely to disturb human habitations. Faster rotors operate at lower torque, which means lighter, less costly drive chain components. Challenges unique to the off shore environment include resistance to corrosive salt waters, resilience to tropical and extra tropical storms and waves, and  co existence with marine life and activities. Greater distances from shore create challenges from increased water depth, exposure to more extreme open ocean conditions, long distance transmission on high voltage submarine cables, turbine maintenance at sea and accommodation of  maintenance personnel.

A primary challenge for off shore wind energy is cost reduction. Developing the necessary support infrastructure implies one time costs for customized  vessels, ports and harbor upgrades, new manufacturing facilities and work force training. In general  capital costs are twice high as land based, but this may to be partially off set by potentially higher energy yields-as much as 30 percent or more. 

As experienced with land based wind systems over the past decades, off shore wind costs are expected to drop with greater experience, increased deployment and improved technology. To make off shore wind energy most cost effective, some manufacturers are designing larger wind turbines capable of generating more electricity per turbine. Several manufacturers are considering 10 MW turbine designs, and program  such as up wind in European union, are developing tools to allow these large machines to emerge.

In shallow water, the sub structure extends to sea floor , and includes monopoles, gravity basis and suction buckets. In transitional depth new technologies are being created or adopted from oil & gas industries, including jacket structures and multiple file  foundations which also extends sea floor. At same depth if no longer economically feasible to have rigid structure fixed to the sea floor, and floating  platform may be required. Three idealized concepts have risen for floating platform designs, including the semi submersible the spar buoy, and tension leg platform each which use different method for achieving static stability. Although it is not yet known which of these three designs will deliver the best system performance, designers seek plat form that are easy to install and minimize overall turbine loads. To determine the optimized design point advanced computer simulation models need to be developed and validated.


Economics off shore wind power

Off shore wind projects are analyzed in terms of initial  capital costs (ICC) as well as their life cycle costs, also known as the levelized cost of energy (LCOE)  . Cost profits of each type for U.S. market are difficult because of many regulatory and technical uncertainties and lack U.S. market experience . Although the European market is based a more developed supporting infrastructure and substantially different regulatory policy and physical environments, preliminary analysis of that experience provide some pluvial useful insight.

As in the case of land  based projects, the ICC for offshore wind power has been increasing over  time. Costs jumped approximately 55 percent between 2005 and 2007 leading to an estimated average capital investment of 4250 U.S. dollars per KW for an off shore wind project in 2010. The wind turbine it self contributes 44 percent of this total. In general capital costs are expected to increase with distance land and water depth and decreases as the size of project increases as result of economics of scale. As technology matures the prices expected to decline.

The LCOE calculations, or the cost of energy produced 20 year life of project, are based on average factors, many of which are currently unknown and must be projected. In addition ICC these include operations and maintenance(O&M) cost of the financing, amount of energy to be generated, long term system reliability and decommissioning costs.

O&M costs are higher for off shore wind turbines than land based turbines, primarily because of access issues. It is simply more difficult to perform work at sea. Although more research is needed to determine the range of these off shore O&M cost, some reports estimate they are two or three times higher than on land and can reach 20 percent to 30 percent of LCOE.

The LCOE for off shore wind is heavily influenced by the relatively high ICC and the cost of financing. A significant part of financing cost based on perception of financial risk and project uncertainties. These risk perceptions could potentially be lowered through research on virtually all of the factors that make up the LCOE for off shore wind, but larger impacts will come from confidence built on deployment experience.

Environmental socio economic risks

Risks associated with off shore wind energy are not as serious or potentially catastrophic compared with other energy technologies. Also wind turbines can be deployed relatively quickly to reduce green house gases, reduce other air emissions and help conserve water   resources. Potential risks in deploying off shore wind projects can typically be reduced through development and use of best management protection management principal. Although risks are site specific, research at European installed projects and U.S. base line studies are building knowledge base and helping to inform decision makers and public. 

Primary stake holder concern regarding off shore wind facilities include

Marine animal population : although European studies conducted to date suggest that the impact of off shore wind facilities on marine and animal populations are minimal.

Visual effects ;   coastal residents in view of an off shore wind farm may voice concern about visual impacts. More research is needed to better understand coastal communities and their ability to accept changes to the sea scrape.

Noise  : based on European studies and experience to date the most significant environmental impact stem from noise associated with pile driving during the construction phase. Mitigation strategies may be effective in reducing risk. Alternative technology can also implemented if appropriate to avoid some of pile driving activity.

Marine safety : the possibility of ship colliding with turbine poses a potentially significant risk to the marine environment from fuel leaks from disabled ship or human safety should turbine collapse. 

Finding and conclusions

Overall the opportunities for off shore wind are abundant, yet barriers and challenges are also significant. In the context greater energy, environmental and economic concern the nation faces, accelerating the deployment of off shore wind could have tremendous benefits for coastal based countries. Technological needs are generally focused on making off shore wind technology economically feasible and reliable and expanding the resource are to accommodate more regional diversity for future off shore projects. Prudent sitting strategies that involve stake holders at site would reduce potential risks. In short term reducing risk will stimulate economic growth accelerate permitting time frames and help address important aspect of  reducing global green house gases.

Nuclear energy and safety culture

Nuclear energy safety culture

Internationally the Atomic Energy Agency “ work with its member states and multiple partners world wide to promote safe, secure and peaceful operation of nuclear technologies. Some scientists say that the 2011 Japanese nuclear accidents have revealed that nuclear industry lacks sufficient over sight leading to renewed calls to redefine  the mandate of IAEA so that it can better police nuclear power plants world wide. There are several problems with IAEA says Najmedin Meshkata of university of southern California.

It recommends safety standards, but member states are not required to comply, it promotes nuclear energy, but it is the sole global organization over seeing nuclear energy industry, yet it is also weighed down by checking compliance with nuclear non-proliferation treaty (NPT)

Many nations utilizing nuclear power have special institutions over seeing and  regulating nuclear safety. Civilian nuclear safety in U.S. regulated by Nuclear Regulatory Commission (NRC). The safety of nuclear power plants and material controlled by U.S. Government for research, weapon production and those powering naval  vessel is not governed by the NRC. In U.K. nuclear safety is regulated by office of nuclear regulation (ONR) and defense nuclear safety regulator (DNSR). The Australian radiation and nuclear safety agency (ARPANSA) is the federal government body that monitor and identifies solar radiation and nuclear radiation risks in Australia. It is the main body dealing with ionizing and non -ionizing radiation and publishes material regarding radiation projection.

Other agencies include

. Canadian nuclear safety association
. Radiological protection institute of Ireland
. Federal atomic energy agency in Russia.
.Kemfysische  Dienst (NL)
. Pakistan nuclear regularity authority
. Bunde Samt for Strahlenschutz (DE)
. Atomic energy regulatory board (AERB) in India

Nuclear power plant

Nuclear power plants are some of most sophisticated and complex energy systems ever designed. Any complex system, no matter how well it is designed and engineered cannot be deemed failure proof Stephanie Cooke has reported.

The reactors themselves were enormous complex machines with an in calculable of things that could go wrong. When it is happened at Three Mile Island in 1979 another fault line in the nuclear world was exposed. One mal function led  to another and series of others until the core reactor it self began to melt and even the world’s most highly trained nuclear engineers did not know how to respond. The accident revealed serious deficiencies in a system that was meant to protect public health and safety.

A fundamental issue related to complexity is that nuclear power systems have exceedingly long life times. The time frame involved from the start of construction of a commercial nuclear power state though to safe disposal of its last radio active waste may be 100 to 150 years.

Failure mode of nuclear power plants

There are concern that a combination of human and mechanical error at nuclear facility could result in significance harm to people and environment.

Operating nuclear reactors contain large amounts of radio-active fission products which, if dispersed, can pose a direct radiation hazard contaminate soil and vegetation, and be ingested by humans and animals. Human exposure at high enough level can cause both short term illness and death and long term death by cancer and other diseases.

Nuclear reactors can fail in a variety of ways. Should the instability of nuclear materials generate un expected behavior, it may result in un controlled power excursion. Normally  the cooling system in a reactor is designed to be able to handle the excess heat this causes. However , should the reactor also experience a loss of coolant accident then the fuel may meet or cause the vessel it is contained in to over heat and melt. This event is called nuclear melt down.

After shutting down for some time the reactor still needs external energy to power its cooling systems. Normally this energy is provided by power grid that the plant is connected or by emergency diesel generators. Failure to provide power for cooling systems as happened in Fukushima can cause serious incidents.

Because the heat generated can be tremendous immense pressure can build up in the reactor vessel, resulting in steam explosion, which happened  at Chernobyl. However  the reactor design used at Chernobyl was unique in many ways. For example it had a large positive void coefficient meaning a cooling failure caused reactor to power rapidly escalate. Typical reactor design have negative void coefficient a passively safe design. However this design may not protect from melt down if cooling system is damaged.

More importantly though the Chernobyl plant leaked a containment structure. Western reactors have this structure, which acts to contain radiation in the event of a failure. Containment structure are by design, some of strongest structure built by mankind. However during serious incidents engineers may need to vent the containment intentionally as other wise it would crack due to excess of pressure .

Vulnerability of nuclear plants attack

Nuclear power plants are generally considered hard targets. In U.S. plants are surrounded by double row of tall fences which electronically monitored. The plant grounds are patrolled by a sizable force of armed guards. The NRCs  design basis threat criteria for plant is a secret and so what size attacking force the plants are able to protect against is unknown.

However to scram (make emergency shut down) plant takes fewer than 5 seconds which unimpeded restart takes hours, severely hampering a terrorist force in a goal to release radioactivity.

The most important barrier against release of radioactivity in the event of an aircraft strike on a nuclear power plant is containment and its missile shield. Current NRC chair man Dale Klein has said  “ nuclear power plants inherently  robust structures that our studies show  provide adequate protection in hypothetical attack. The NRC has also taken actions that  require nuclear power plant operators to be able to manage large fires or explosions- no matter what has caused them.

In addition supporters point large  studies carried out by the U.S. Electric power research institute that tested robustness of both reactor and waste fuel storage and found they should be able to sustain a terrorist attack comparable to the September 11 terrorist attack in U.S. spent fuel is usually housed  inside plants “ protection zone “ or spent fuel shipping cask, stealing it for use dirty bomb is extremely difficult. Exposure to the intense radiation would almost certainly quickly incapacitated or kill any one who attempts to do so.

In September 2010, analysis of the stuxnet computer worm suggested that it was designed to sabotage a nuclear power plant. Such cyber attack would by pass the physical safe guards in place and so exploit demonstrates an important vulnerability.

Plant location

In many countries nuclear power plants are often located on the coast, in order to provide a ready source of cooling water for essential service water system. As a consequence the design needs to take risk of flooding and tsunami into account.
Failure to calculate the risk of flooding correctly leads to level 2 event on international nuclear event on the international nuclear event scale during 1999 Blayais  nuclear power plant flood, while flooding caused by 2011 Tohoku earth quake and tsunami lead to the Fukushima Daaichi nuclear accidents.

The design of plants located in seismically active zones to be taken into account. Japan , India china and U.S. are among countries to have plants in earth quake prone regions. Damage caused to Japan Kashiwazaki- Kariwa  nuclear power plant during 2007 Chuetsu offshore earthquake underlined concerns expressed by experts in Japan prior to Fukushima accidents, who have warned of domino -effect nuclear power plant earth quake disaster.

Nuclear safety system

The  primary objective of nuclear safety systems as defined by  nuclear regulatory commission are to shut down reactor, maintain it in shut down condition, and prevent release of radio active materials during events and accidents. These objective are accomplished using a variety of equipment, which part of different systems, of which each perform specific functions.

Hazards of nuclear material

Nuclear material may be hazardous if not properly handled or disposed of . Even when properly contained fission by products which are no longer useful to generate radioactive waste which must be properly disposed of. Spent nuclear fuel that is recently removed  from nuclear reactor will generate large amounts of decay heat which will require pumped water cooling for an year or more to prevent over heating. In addition material exposed to neutron radiation-present in nuclear reactors may become radioactive on its own right, or become contaminated with nuclear waste. Additionally toxic or dangerous chemicals may be used as a part of plant operation which need be properly handled and disposed off.

New nuclear technologies

The next nuclear power plants to be built will likely be generation 111 or 111+ design and few of such are already in operation in Japan. Generation iv  reactors would have greater improvements in safety. These designs are expected to be passively safe or nearly so, perhaps even inherently safe.

Some improvements made are having three sets of diesel generators and associated emergency core cooling systems rather than just one pair, having quench tanks (large cooled tanks) above the core that open into to automatically, having double containment ( one containment building inside another ) etc.

However safety risks may be the greatest when nuclear systems are newest, and operators have less experience with them. Nuclear engineer David Loch Baum explained that almost all serious nuclear accidents occurred with what was at the time the most recent technology. He argues that “ the problem with new reactors and accident is two fold. Scenarios arise that are impossible to plan  for simulations, and hence human mistakes.  As one director of U.S. RESEARCH laboratory put it “ fabrication, construction ,operation and maintenance of new reactors will face a steep learning curve. Advanced technologies will have a heightened a risk of accidents and mistakes. The technology is proven but people or not.

safety culture and human errors

one relatively prevalent notion in discussions of nuclear safety is that the safety culture. The international nuclear safety is that of safety advisory group defines term “ as personnel dedication accountability of all individuals engaged in any activity which has bearing on the safety of nuclear power plants. The goal is design systems that use human capabilities in appropriate ways, that protect systems from human frailties, and that protect human from hazardous associated with system.

At same time there is some evidence that operational practices are not easy to change. Operators  almost never follow instruction and written procedures exactly and “ violation of rules appear to be quite rational, given the  actual work load and timing constraints  under which the operator must do their job” many attempts to improve nuclear culture “ were compensated by people adopting to change in an unpredicted way.

An assessment conducted by commissariat Energy Atomique (CEA) in France concluded that no amount of technical innovation can eliminate risk of human induced errors associated with operation of nuclear power plants. Two types of mistakes were deemed most serious ; errors committed during field operators, such as maintenance and testing that can cause an accident and human errors made during small accidents that cascade to complete failure.

According to Mycle Schneider, reactors safety depends above all on a “ culture of security, including the quality of maintenance and training, the complete of the operator and work force and the rigor of regulating over sight. So better designed new reactor is not always safe one and older reactors are not necessary dangerous than new one. The 1978 Three Mile Island accident in U.S. occurred in a reactor that had started operation only three months earlier and Chernobyl disaster occurred only two years of operation. A serious loss of coolant occurred at French Civaux-1 reactor in 1998 less than five months after start up.

Experts say that the “ largest single internal factor determining the safety of a plant is the culture of security of regulators, operators and work force- and it is essential to create such a culture.

Core damage risk

The AP 1000 has maximum core damage frequency of 5.09X 10-7  per plant per year. The evolutionary power reactor (EPR) has a maximum core damage frequency 4x 10-7 per plant for year. General electric has recalculated maximum core damage frequency for year per plant for its power plant design.

BWR/4------ 1x10-5
BWR/6-------1x10-6
ABWR-------2x10-7
ESBWR------3X10-8

HEALTH IMPACTS

In spite of accidents studies have shown the nuclear deaths are mostly in uranium mining and that nuclear energy has generated for fewer deaths than the high pollution levels that result from the use of conventional fossil fuels.

The speed of nuclear construction program in China has raised safety concerns. The challenge for government and nuclear companies is to “ keep an eye on growing army of contracts and sub contractors who may be tempted to cut corners. China is advised to maintain nuclear safe guards in business culture where quality  and safety are some times sacrificed in favor of cost cutting, profits and corruption. China asked for  international assistance in training more nuclear power plant inspectors.