Summary of Lecture Series

According to energy consumption map, about 38% energy resources from entire world have been used to generate electricity. This electricity comes from hydro, biomass, geothermal, wind, solar, nuclear, coal and natural gases. The other sources such as petroleum and natural gases go to industrial, commercial, residential, light-duty vehicle, freight and air craft. Nuclear only used for generating electricity which is about 8.13% from total portion of energy resources. The energy consumption in form of transportation, industry, agriculture, domestic and food the day by day is keep increasing according to The British Royal Commission on Environmental Pollution. With the increasing of demand in electricity, the minimum demand (base load) is about 10,258 MW. The latest peak demand is about 15037 MW. How do meet the base load 10,258 MW demand? This base load needs to be supplied by coal, gas and hydro.

All this conventional technologies produce the CO₂ green house gases by process of combustion. This green house gases clearly is not good for our world.  These green gases will make the effect of the earth’s surface warming because it is preventing the infrared radiation from passes through the atmosphere and lost in space. The average concentration of CO₂ today is about 388.15 parts per million (ppm). We must remember that, the breakaway emission of CO₂ is 450 ppm!! With the current population growth, in year 2025, the number of 450 ppm will be achieved. We cannot live anymore when we achieved that number. We are getting closer and closer.

 Increase in carbon concentration is related with the increase in temperature. When the temperature goes up, the temperature at North Atlantic and the Southern Ocean will also goes up. Again, we must remember that this place is the coolest place in our world. This place is the important part of thermahaline circle or The Great Conveyor Belt. What will happen if the heart of this Great Conveyor Belt is affected? We must highlight that, all the phenomenon, the climate change in this world is related with this Great Conveyor Belt. The hot wind is circulated around the world followed this conveyor path and the hot wind is cooled at the North Atlantic and Southern Ocean. We cannot let the heart of Great Conveyor Belt be effected by the rise of temperature. So we have to turn to green energy.

Recovery of uranium for non-conventional Malaysian sources

In this topic, we will learn that the security of uranium fuel supply is an important aspect for countries which that using nuclear power energy. The alternative sources of uranium are identified from the present conventional uranium mines with respect to the present of high demand for nuclear power and uranium. Futhermore, this topic will also describes about the material such as Xenotime(YPO₄) which is a yttrium phosphate mineral is a recovered by product from tin mining industry. Unlike another rare earth mineral called monazite, there is higher content of uranium in Xenotime as to that of thorium. For our knowledge, there are about 1-2% U₃O₈ found in this material and the highest compared to the other tin by product minerals.

The process that we called a “hydrometallurgy” was developed by researcher to produce uranium and yttrium oxide concentrates. This process involved alkaline fusion, acid leaching and frictional precipitation stages. The inclusion fractional precipitation stage in the process enables to separate yttrium from the uranium. Previously, the uranium contaminated organic DEHPA was sent to Malaysian Nuclear Agency for storage and disposal when the Asian Rare Earth plant in Lahat Datu, Perak was closed in year 1996. As we can know that, DEHPA was used as a solvent extraction solvent for separation of light and heavy rare earth elements. There is about 31,500 liters of this waste and EDXRF analysis show that the uranium content is 990 ppm and the total rare earth content is 25,890 ppm present in this waste.

Hence, the distribution coefficient and separation factors for these elements were determined so as to conduct an efficient stripping process. The Malaysian tin by product minerals are also known to be contaminated with radioactive elements. For our general information, the uranium content in Malaysian Zircon mineral ranges from 0.06-0.18% U₃O₈ and Malaysian ilmenite from 0.01-0.07% U₃O₈. As this radioactive elements is found to be contaminated both of the surface  as well as in the crystals, physical and chemical processes were developed to remove them.

The operation and maintenance of electron beam machines from nuclear Malaysia’s experiment.

First of all, we known that the first high energy electron beam machine (EPS3000) was installed in Nuclear Malaysia around 1991. At the beginning, it was a prototype machine that produced by Nissin High Voltage (NHV) with variable energies from 0.5 to 3.0 MeV and maximum power of 90 kWatt. The machine was initially used and operated for research purposes but later the irradiation service was opened for local industries.

Apart from the EPS3000, a smaller and self –shielded Curetron was also installed. It was having energy around 200 keV and maximum power about 0.4 kWatt. By the way, the machine is used only for surface curing or coating related research. The operation of the both machine have carried out by local technician. However, at the earlier stage, the major maintenance works were conducted by designated engineers that provided by the manufacturers.

Over time and experience gained, most of the maintenance are now being carried out by the local engineers and technician. In late 2009, a new 1 MeV, 50 kWatt manufactured by BNP of Russia was installed to complement the current  irradiation service. Lastly we can conclude, this is a different type of EB machine but in term of operational safety and maintenance, the requirements are almost similar.

Why is having a nuclear power plant in your local area is A GREAT IDEA?

Nowadays, the nuclear energy is the greenest energy in the Earth. It is greener as we compared with the other power generating plant in Malaysia. Other construction of power plant is using high amount of concrete to build the structure. As we know, concrete will release high amount of carbon dioxide in the air. For example, now we have under construction Bakun Dam located at Sungai Balui Sarawak. This dam will be the tallest concrete dam in the world and becoming one of the largest dams in Asia. The dam has about 16.71 million cubic meters of filled volume and catchment area about 14,750 km square. The gross storage capacity is 43,800 million cubic meters. Can you imagine how much concrete is required to build this dam? How much carbon dioxide will be released by the concrete? How much environmental creatures need to be sacrificed with that large amount of catchment area? Absolutely, having the nuclear power plant is A GREAT IDEA.

As we can see from TNB itself, but not from political view, TNB actually not completely produce the electricity itself. TNB also depends to the other producer such as IPP (Independent Power Plant). The IPP is owned by individual party such as Tan Sri Al-Bukhary, Vincent Tan and so forth. Because of that, TNB need to buy the electricity from them, then TNB sell to us. We can see that, the price of electricity is indirectly depends from other producer. Then Malaysian life will be affected with the rise of fuel cost and operation cost of IPP. As an alternative, the nuclear energy is more profitable than other energy production. This could help to reduce the electricity cost and the Malaysian should think about it. Absolutely, having the nuclear power plant is A GREAT IDEA

Control Rod

Hi.Today we would like to talk about control rod.As mention before,control rod is one of the main component of nuclear reactor.As we all know,the nuclear power plant can generate the tremendous power,heat and energy through the nuclear fission.However,we need to control it in predictable manner.The failure of controlling control rod will cause the incident like the Chernobyle disaster and Stationary Low-Power Reactor Number One explosion.Control rod can be made using chemical elements which can control the rate of fission of uranium.

Actually,why the nuclear reactor need to control? It is important to make sure the reaction is sustained rather than to start the chain reaction.In case of emergency situations such as a sudden mechanical or structural damage, the reactor needs to be shut down quickly in order to prevent any major disaster like Chernobyl which could be very costly in terms of loss to life and environment.Without having the nuclear reactor in control, the control rod might be melted down. 

The control rod can absorb the amount of neutron to control the nuclear fission reaction.So the material being used in control rod must having high neutron absorbing capacity. Commonly material used are cadmium, boron, iridium and hafnium. For PWR nuclear reactor,the control rod is place on top of reactor but for BWR nuclear reactor,it is place at the bottom. This is because the stim generated inside the BWR reactor will push the control rod if control rod is place on top.

Advantage of having Nuclear Energy in the future.

In the world today, many countries, especially big, heavily industrialized nations rely on nuclear power to satisfy their country’s energy needs. Such nations require huge amounts of energy to run their country. Various

consumers of energy and electricity include industries, residences, commercial establishments, military assets, governmental buildings, agriculture, transport and so on.

 Massive usage of electricity on developed country.

Especially in extremely populated countries, there are in extremely high demand. The bitter truth is, it is just not possible to fill in such a high demand with just conventional sources of energy, countries look toward unconventional sources of energy such as solar, wind and nuclear energy. The yield of solar and wind energy is not that high. Nuclear energy is the answer for sustainable electric source in the future.

The reason why nuclear energy is important for future energy consumption is

1) Nuclear reaction release tremendous amounts of energy. Nuclear energy is so immense that one nuclear plant may provide electricity for a really large area. Thus it is important to have nuclear reactor to sustain future energy demand. This will be a stepping stone for a country such as Malaysia to be recognized as a developed country.

2) Nuclear energy doesn't emit anything into the atmosphere like polluted air, smoke or anything of that sort. France, which has embraced nuclear power has some of the most cleanest air in the world. this is mostly because of the heavy use of nuclear energy and minimum dependence of coal or oil based power plants. Future energy demand will be so demanding that it will be a major concern on the environment if we keep on using fossil fuel as our main source of energy and Malaysia need to take part in preserving the global environment.

Nuclear reactor only emits steam into the air (left) while conventional reactor emits greenhouse gas into the air (right)

to be continue....

references:

1. http://www.buzzle.com/articles/advantages-and-disadvantages-of-nuclear-energy.html 
2.  http://www.planete-energies.com/content/nuclear-energy/future/advantages.html

Nuclear Power Plant

 

What is nuclear power plant (NPP)? Actually, it can be defined as an electrical generating facility using a nuclear reactor as its heat source to provide steam to a turbine generator. In our country Malaysia, there are many type of electricity-generating power station in Malaysia. The make use of hydro-power, gas-fired, coal-fired (combined gas/coal), oil fired, biomass and hybrid power are remain as the main sources to generate electricity. Our country has enough skilled labor to operate power plant. It is simple because we have experience about how to operate hydro-power, gas-fired, coal-fired and etc.The whole system of power plant including steam turbine generator also we are capable of. How about if we replace the others heat sources with nuclear reactor? The concept stills the same, the steam turbine generator still being used. The different is only the heat source. It is sound easy, but the acceptation of Malaysian about nuclear reactor need to be considered. They need to be provided with simple and true information about nuclear power plant. Nuclear reactor is a device in which nuclear fission may be sustained and controlled in self-supporting nuclear reactor. It is heart of a nuclear power plant. A fissionable material of fuel, a moderating material, a reflector to conserve escaping neutrons, provisions of removal heat, measuring and controlling instruments and protective devices are include as parts of nuclear reactor. Figure above shows the general idea how to use nuclear reactor to produce the electricity.

What are the major components of nuclear reactors? There are 5 major components of nuclear reactor as listed as below.

ª      Nuclear fuel

ª      Moderator

ª      Coolant

ª      Reactivity Control Material

ª      Structural Material

 The nuclear fuel is used to undergo nuclear fission by neutrons. It must have high thermal conductivity, irradiation, chemical stability and also excellent nuclear characteristics. The example fuel that can be used is uranium, etc. The moderator is used to reduce neutron energy by scattering without significant capture. It must have desirable characteristics to function efficiently such as large scattering cross section, small absorption cross section, large energy per collision and low atomic number. The example of moderator can be used are Deuterium, graphite and etc. For coolant, it is use to remove the fission heat from the primary heat source such as a reactor core or breeding blanket. The coolant must have excellent heat transfer, chemical stability, small pumping requirement, irradiation stability and abundance (low cost).The most natural coolant is water. The reactivity control material is needed to control the neutron flux in the core by absorbing neutrons. It can be done by using control rod. The structural material is used to maintain geometry. The structural must has high strength, ductility, corrosion resistance, small absorption cross section and high thermal and irradiation resistance. Zircaloy can be used as material.

 Picture above shows the basic components of nuclear power plant. The most common of nuclear reactor  type  that been used nowadays are Pressurize Water Reactor (PWR) and Boiling Water Reactor (BWR). The picture above shows the example of PWR nuclear reactor type.PWR and BWR and the other type of nuclear reactor that commonly used will be discussed in other post.

   
Reference
*Introduction to Nuclear Engineering  MEHB513