Fun Facts #5

Did you know?

On December 2, 2011 is the 69th years anniversary of nuclear energy. Back in 1942 at this date, Enrico Fermi, Leo Szilard and their colleagues successfully achieved the first man made and controlled nuclear chain reaction. More interesting it was made in squash court of University of Chicago's Stagg Field.

Fermi also play major role in establishing the American Nuclear Society (ANS) in December 11, 1954.

Also on December 2, 1957, the first full scale commercial nuclear power plant in the world went full power in Shippingport, Pennsylvania.

A 1957 view of the Shipping port of Atomic Power Station

Top 10 Countries using Nuclear Power

Nowadays, nuclear energy has contributes a lot on generating power to meet the demands that is increasing each year. Although nuclear energy has created more fears to the public since Fukushima incident yet more nuclear power plant is expected to operate in the future. Nuclear energy may become an option to Malaysia and other countries which reach in energy resources. Some of countries may have nuclear energy as main power generating due to lack of energy resources. Below is the countries which highly depends on nuclear energy to generate power.

10. Hungary (37%)

9. Switzerland (39%)

8. Armenia (40%)

7. Slovenia (41%)

6. Sweden (42%)

5. Ukraine (47%)

4. Belgium (54%)
3. Slovakia (56%)

2. Lithuania (72%)

1. France (76%)

Nuclear Fuel Cycle

These are the various steps that together make up the entire Nuclear Fuel Cycle:

1. Mining and milling

Uranium is usually mined by either surface (open cut) or underground mining techniques, depending on the depth at which the ore body is found. In Australia the Ranger mine in the Northern Territory is open cut, while Olympic Dam in South Australia is an underground mine (which also produces copper, with some gold and silver). The newest Canadian mines are underground.

From these, the mined uranium ore is sent to a mill which is usually located close to the mine. At the mill the ore is crushed and ground to a fine slurry which is leached in sulfuric acid to allow the separation of uranium from the waste rock. It is then recovered from solution and precipitated as uranium oxide (U₃0₈) concentrate.*

* Sometimes this is known as "yellowcake", though it is finally khaki in colour.

Some mines, notably in the USA and Kazakhstan, use in situ leaching (ISL) to extract the uranium from the ore body underground and bring it to the surface in solution. It is recovered in much the same fashion.

U₃0₈ is the uranium product which is sold. About 200 tonnes is required to keep a large (1000 MWe) nuclear power reactor generating electricity for one year.

2. Conversion

Because uranium needs to be in the form of a gas before it can be enriched, the U₃0₈ is converted into the gas uranium hexafluoride (UF₆) at a conversion plant.

3. Enrichment

The vast majority of all nuclear power reactors in operation and under construction require 'enriched' uranium fuel in which the proportion of the U-235 isotope has been raised from the natural level of 0.7% to about 3.5% to 5%. The enrichment process removes about 85% of the U-238 by separating gaseous uranium hexafluoride into two streams: One stream is enriched to the required level and then passes to the next stage of the fuel cycle. The other stream is depleted in U-235 and is called 'tails'. It is mostly U-238*.

* Figures in the diagram assume enrichment to 3.5% U-235 and a tails assay of 0.25%. The 220t figure should be 172t (146 tU)

So little U-235 remains in the tails (usually less than 0.25%) that it is of no further use for energy, though such 'depleted uranium' is used in metal form in yacht keels, as counterweights, and as radiation shielding, since it is 1.7 times denser than lead.

Today's enrichment plants use the centrifuge process, with thousands of rapidly-spinning vertical tubes. A few older plants also continue. Research is being conducted into laser enrichment, which appears to be a promising new technology.

A small number of reactors, notably the Canadian CANDU reactors, do not require uranium to be enriched.

4. Fuel fabrication

Enriched UF₆ is transported to a fuel fabrication plant where it is converted to uranium dioxide (UO₂) powder and pressed into small pellets. These pellets are inserted into thin tubes, usually of a zirconium alloy (zircalloy) or stainless steel, to form fuel rods. The rods are then sealed and assembled in clusters to form fuel assemblies for use in the core of the nuclear reactor.

Some 27 tonnes of fresh fuel is required each year by a 1000 MWe reactor.

5. The nuclear reactor

Several hundred fuel assemblies make up the core of a reactor. For a reactor with an output of 1000 megawatts (MWe), the core would contain about 75 tonnes of low-enriched uranium. In the reactor core the U-235 isotope fissions or splits, producing heat in a continuous process called a chain reaction. The process depends on the presence of a moderator such as water or graphite, and is fully controlled.

Some of the U-238 in the reactor core is turned into plutonium and about half of this is also fissioned, providing about one third of the reactor's energy output.

As in fossil-fuel burning electricity generating plants, the heat is used to produce steam to drive a turbine and an electric generator, in this case producing about 7 billion kilowatt hours of electricity in one year.

To maintain efficient reactor performance, about one-third of the spent fuel is removed every year or 18 months, to be replaced with fresh fuel.

6. Used fuel storage

Storage pond for used fuel at UK reprocessing plant

Used fuel assemblies taken from the reactor core are highly radioactive and give off a lot of heat. They are therefore stored in special ponds which are usually located at the reactor site, to allow both their heat and radioactivity to decrease. The water in the ponds serves the dual purpose of acting as a barrier against radiation and dispersing the heat from the spent fuel.

Used fuel can be stored safely in these ponds for long periods. It can also be dry stored in engineered facilities, cooled by air. However, both kinds of storage are intended only as an interim step before the used fuel is either reprocessed or sent to final disposal. The longer it is stored, the easier it is to handle, due to decay of radioactivity.

There are two alternatives for used fuel:

• reprocessing to recover the usable portion of it
• long-term storage and final disposal without reprocessing.

7. Reprocessing

Used fuel still contains approximately 96% of its original uranium, of which the fissionable U-235 content has been reduced to less than 1%. About 3% of used fuel comprises waste products and the remaining 1% is plutonium (Pu) produced while the fuel was in the reactor and not "burned" then.

Reprocessing separates uranium and plutonium from waste products (and from the fuel assembly cladding) by chopping up the fuel rods and dissolving them in acid to separate the various materials. Recovered uranium can be returned to the conversion plant for conversion to uranium hexafluoride and subsequent re-enrichment. The reactor-grade plutonium can be blended with enriched uranium to produce a mixed oxide (MOX) fuel*, in a fuel fabrication plant.

* MOX fuel fabrication occurs at facilities in Belgium, France, Germany, UK, Russia and Japan, with more under construction. There have been 25 years of experience in this, and the first large-scale plant, Melox, commenced operation in France in 1995. Across Europe about 30 reactors are licensed to load 20-50% of their cores with MOX fuel and Japan plans to have one third of its 54 reactors using MOX by 2010.

The remaining 3% of high-level radioactive wastes (some 750 kg per year from a 1000 MWe reactor) can be stored in liquid form and subsequently solidified.

Reprocessing of used fuel occurs at facilities in Europe and Russia with capacity over 5000 tonnes per year and cumulative civilian experience of 90,000 tonnes over almost 40 years.

8. Vitrification

After reprocessing, the liquid high-level waste can be calcined (heated strongly) to produce a dry powder which is incorporated into borosilicate (Pyrex) glass to immobilise the waste. The glass is then poured into stainless steel canisters, each holding 400 kg of glass. A year's waste from a 1000 MWe reactor is contained in 5 tonnes of such glass, or about 12 canisters 1.3 metres high and 0.4 metres in diameter. These can be readily transported and stored, with appropriate shielding.

This is as far as the nuclear fuel cycle goes at present. The final disposal of vitrified high-level wastes, or the final disposal of spent fuel which has not been reprocessed used fuel, has not yet taken place.

Resource from World Nuclear Association

Fun Facts #4

Did you know that?

Discovery of Uranium

Uranium was discovered in 1789 by Martin Klaproth, a German chemist, who isolated an oxide of uranium while analyzing pitchblende samples from the Joachimsal silver mines in the former Kingdom of Bohemia located in the present day Czech Republic.

Discovery of Uranium Fissionability

It took until 1938 to discover that uranium could be split to release energy, that is fission. This was accomplished by Otto Hahn and Fritz Strassman.

Discovery of Uranium Radioactivity

Henri Antoine Becquerel discovered that uranium was radioactive in 1896.

Replies to Tun Dr Mahathir from UPM student

Various response has been made regarding Tun Mahathir's view on nuclear power. A student (Muhammed Daniel) from Universiti Putra Malaysia (UPM) has reply on Tun Mahathir's view on nuclear energy. Below are his comment:-

Dr Mahathir,

As a student studying physics at UPM who grew up to admire your Vision 2020, I am very disappointed that such a good leader for Malaysia and developing countries has swallowed the unscientific anti-nuclear propaganda pushed by the green environmental movement. I have become convinced for some time that a Nuclear Malaysia is the way to achieve vision 2020 and beyond. However, I could not see a clear way forward. Last week I attended a public lecture at UKM by one of the founders of South Korea‘s peaceful nuclear program, Professor Dr Jong H. Kim. I came away from the talk convinced that South Korea’s 50 yeary peaceful nuclear program is the very best example for Malaysia to follow.

According to Prof Kim, “In the 1950’s we were a devastated and torn nation, we were destroyed by the war between North and South Korea.” Today, Korea is the 13th largest economy in the world, 6th biggest nuclear power producer in the world with $20 000 US per capita income. Not bad for a country who came 177th after the war in terms of economic power. In 56 years, they’ve not only managed to rise from the ashes of war but became a major player in the world economy.

How did they do it? Was it through efficient policy making? Help from the super-powers after the war perhaps? The key, according to Prof Jong was nuclear power.

This was due to the fact that economic growth is directly proportional to nuclear development. How so? More electricity enables more factories to be opened and a higher standard of living for the population. This in return generates diverse science and high technology driven sectors coupled with a comfortable living environment for the masses. The world we live in today is highly dependent upon electricity. We only have to imagine what our lives would be without electricity if there was a blackout for only a few hours. Long term security and resource availability is one of this century’s greatest concerns considering oil reserves in Malaysia will deplete within 20 years time (41 years for the world’s oil reserves) while the world’s coal supply is expected to deplete within the next 155 years. For uranium the picture is better with 233 years left if the current trend of world energy consumption persists. We have to remember that used uranium can be enriched to plutonium. If we combine this into the equation nuclear power can last a whole lot longer, up to 2000 years according to reputable estimates.

During the 1970’s, 77% of Korea’s power was from coal. In the 80’s, 10 years after the opening of Korea’s first nuclear power plant, Kori-1, nuclear power amounted to 9% of the total power produced. This figure shot up to 49% of power generated by nuclear in the 1990’s. Now here’s where it gets very interesting. During the 1950’s after the war, Korea’s GDP per capita was a meagre $876 US. Since the beginning of the nuclear power era in Korea during the 70’s, the figure rose to $1597 per capita. In 2007, the GDP was at an astonishing $20 000 per capita! Prof Kim merrily told the astounded audience that this was because Korea had 20 nuclear power plants. Each nuclear power plant essentially contributed to an increase of $1000 US per capita of GDP.

Where does Malaysia fit into all this, I began to wonder? Prof. Jong later shifted his lecture to the Malaysian aspect of it by describing the difference between our GDP and per capita income. Despite the fact Malaysia’s GDP is 1/5 of Korea’s, an interesting point to note is that our per capita income now stands at $15 000 compared to Korea’s $20 000 US. Not too bad, considering we got this far without having nuclear power. Imagine what Malaysia could do if we had nuclear power!

To put the case hands down for nuclear power, Dr Jong showed a final slide comparing the land in square miles required to build various alternative forms of energy. Top of the list for land requirement was biofuel. The land size of corn required to meet energy demands was bigger than Korea itself! Then came hydroelectric power which floods huge areas of land. Next, came generation of power through wind with 40-70 square miles of land required. Fourth place was photovoltaic cells i.e solar power with 40 square miles and last but not least nuclear power with 0.4 square miles of land required. It struck me yet again that the greenies are crazy. From these land use figures, nuclear is by far the most environment friendly source of power.

During the question time I asked how nuclear energy affected the monthly household electricity bill in Korea. Prof Kim said the electricity bill was greatly reduced and stabilised. For example, in 1950 prior to Korea’s nuclear age, their electric power output was 0.33TW hour and later rocketed up to 403 TW hour. A greater than 1000 fold increase in electric power output! Korea is not at the mercy of the oil and gas supply and demand equation because they rely upon heavy elements such as plutonium and uranium. This enabled the price of electricity to be scaled down due to its huge power output.

The important question of nuclear waste was also raised. “Korea initially had problems finding a suitable place for it. In the end we simply asked any regions of Korea which wanted to have the nuclear waste facility to submit their entries. Four areas submitted their entries where the winner went to the area with an 80% resident approval for building the nuclear waste management facility.

The safety aspect of nuclear power raised important questions from the audience. Prof Kim’s response was straightforward, “The technical aspect of it has long gone been solved. It is relatively safe. If it wasn’t safe why would Korea build not only one but 20 nuclear power plants? What’s left for other countries is only the political will power to do so. We in Korea believe that in order to achieve something, we must have a strong will power to do so. We had a strong will considering our nation is now divided into two. It left a great impact on us to improve ourselves. If a plane was to be questioned on every single detail of it’s security, surely it won’t fly. The same goes with nuclear,” he assured us with a smile.

A professor from UPM asked whether the acceptance of nuclear power in the South was because of North Korea’s involvement in using nuclear for military purposes. “Not at all, I’ll show this satellite photo at night showing the difference between the South and North Korea,” he simply said. Indeed the difference was startling. The south was dazzling with countless dots of lights around the country while the North was pitch black with an exception of one dot. Yes, literally ONE dot. That one dot apparently Prof Kim joked belonged to the residential area of its “dictator”. Nevertheless, it clearly states the difference between a country that used nuclear for peaceful purposes and a country that used it for military purposes.

If South Korea can be recognised not only as a major economic power, but a major nuclear power producer isn’t it time we make more of a name for ourselves than merely rubber, palm oil, and the Petronas Twin Towers? Our Asian neighbours have done it. Vision 2020 is only 11 years away. What are we waiting for?

Muhammed Daniel

Tun Mahathir's View about Nuclear Power Plant for Malaysia

Former Prime Minister of Malaysia Tun Dr Mahathir Mohamad has his own views on using nuclear energy to generate power. Here's are his opinion regarding taken from his blog:-

NUCLEAR POWER

1. With the price of oil going up higher and higher, many in this country are thinking about power generation. At one time the Malaysian Government had decided on a four fuel policy for the generation of electric power. We wanted power plants to use either fuel oil, gas, coal or hydro power. We had excluded the use of nuclear power.

2. Why did we reject nuclear power?

3. I am not a nuclear scientist but I believe I know enough of the dangers of using nuclear (fissionable) material.


4. When Hiroshima and Nagasaki were atom-bombed, the scientists who invented the bombs thought that the destructive effect would be only from the huge explosion due to fissionable material. So did their victims - the Japanese.

5. As a result the Japanese entered the destroyed cities to carry out rescue work and to clean up.

6. It was only later that they realised that the residual radiation would cause a variety of radiation sickness and diseases. The radiation remained harmful for a long period after explosion. Even today there are people who had entered the bombed area in those days who are dying of a variety of diseases, including cancer, contracted through exposure to radiation from the Hiroshima and Nagasaki bombs.

7. I think we all know about the Chernobyl disaster in Russia. Despite thousands of tons of concrete being poured into the site, the power plant is still emitting dangerous radiation.

8. Besides this we should know that radioactive material used as fuel for power generation remain radioactive and dangerous to health after the fuel has been exhausted. The waste cannot be disposed anywhere, not by burial in the ground nor dumping in the sea. It can be reprocessed by certain countries only. This requires the dangerous material to be transported in special lead containers and carried by special ships. Most ports do not allow such ships to be berthed at their facilities. Reprocessing means that the nuclear material again becomes active and harmful to health.

9. The fact is that we do not know enough about radioactive nuclear material. Once it is processed it remains a source of danger forever.

10. We have some experience dealing with radioactive material. In Perak we have a site where we had buried by-products of tin mining (amang) which had been processed to become radioactive and which was used to colour television. We had poured tons of cement on the buried material. More than one square mile of the burial site is barred to humans. The site is still radioactive and dangerous.

11. If we have a nuclear plant, besides not being able to get rid of nuclear waste, we may have accidents which can endanger people living even far away because of the material being carried by water (ground water) and wind.

12. I think the authorities should rethink the idea of nuclear power plants. Scientists do not know enough about dealing with nuclear waste. They do not know enough about nuclear accidents and how to deal with them.

13. Until we do, it is far better if Malaysia avoids using nuclear power for electrical generation.

Fun Facts #3

Do you know?

Radiation from X-ray is also equivalent to the radiation release from nuclear power plant (0.05 mSv) yearly.

click image for better view

Fun Facts #2

Did you know?

The amount of hot air produced by the nuclear industry for a week is enough to heat 500,000 homes.

Fun Facts #1

Did you know?

A single uranium pellet about the size of a standard pencil eraser contains as much energy as 17,000 cubic feet of natural gas, 1,780 pounds of coal, or 149 gallons of oil.