Some light interesting reading~ 3:58 PM

Just surfing when I saw this one, look quite interesting considering Fast Reactor is still something new. For those who totally lost, Fast Reactor make use of fast neutron instead of normally slow (or as they called it, thermal) region.

The book is written by the two leading engineers and Argonne National Laboratory Associate Directors behind the integral fast reactor,  Dr. Charles E. Till and Dr. Yoon Il Chang

More about the book is given at its CreateSpace publishing page, and you can purchase it at Amazon.com but it will cost you US$18 though. Yet, I think it's a must have for those who really love into FR stuff~

news: Plentiful Energy – The book that tells the story of the Integral Fast Reactor

Survey Result 10:31 PM

Here's the result from our survey, which is about general public acceptance of nuclear power plant in Malaysia (click on the image to zoom in) -

From our result statistic, we found that majority of the respondents are aware of the nuclear power generation. They know what nuclear can give and help they in energy source. Some also respond positively on the waste, the carbon emission, an the safety. Other than that, some also still with their principle, not supporting nuclear. It is understood as the effect of nuclear bombing and explosion showed a great impact in the affected society. Ours my be taking some lesson, avoiding the same from happening towards our own.

The question about feed in tariff, it is quite as expected as we got most " No"  for the question "Are you willing to pay more to support renewable energy and by how much in tariff increase" . In my humble opinion, Malaysian should change their mind. Most of them. Wanting cheap energy but never want to pay more. Well i seriously not putting any blame of Malaysians themselves. Maybe the salary itself does not enough or maybe the lame perception is permanently passed by generation to generation. 

I am not capable to comment more on the recent energy and power status in Malaysia. It is more political that we thought. 

To conclude, I found that Malaysian is not fully blinded from the positiveness of nuclear power. But still a lot more need to do to convince people on nuclear. For the future generation. - msanne 

General Public Opinion on Malaysia Nuclear Power Plant 10:28 PM

Floating Nuclear Power Plant 12:00 PM

Have you ever heard of floating nuclear power plant? Russia has made such a big, significant step in designing the new nuclear power plant. This new nuclear power plant was designed after the cooperation between Indonesia and Russia.

[source of image]

news credited to RIANOVOSTI, Russia

Nuke Fact #4 7:00 PM

Nuclear Waste Storage – Nuclear waste is just like another industrial and medical waste, which will go through certain phase, carefully to avoid any leakage to the environment. For sure nuclear waste is not like any other normal waste. Take a look at this simple explanations of waste management in info graphic .

The underground facility storage is not anywhere near the residential area. It is somewhere far away from public present. People need to thrust this waste management to accept nuclear energy.

Typical Malaysian Misconceptions 8:30 PM

The post is quite lengthy but please take your time to read. I hope we can exchange thoughts about this matter. 

Thanks - nesca

-----------------------------------------------------

Like what I mentioned in our first post;

We are always afraid of the things we do not know. We are quick to judge, criticize and even hate the unknowns without fully understanding the causes. It is not entirely our fault to have fear. In fact, it is fear that helps us to differentiate between good and bad. But we must not cloud our visions by relying on fear alone. One must learn and think wisely before making any action. 

• Everyone is afraid of nuclear. In fact everyone will have the same image of mushroom clouds in Hiroshima & Nagasaki whenever the word is mentioned. Why would anyone use nuclear for energy generation when there are other safer alternatives available for people to choose. Why play the risk?

• All this while, I was like that too. I always favour hydro-power power plant over the others. Like everyone else, I'm afraid of the word nuclear itself. Nuclear means bomb. And bomb means destruction. It resembles doomsday.

• Well, that's what I thought until I take a nuclear subject for my degree study. It's an elective subject by the way so why would you think I choose this to fill my degree credit hours eh? To be honest, I'm just curious.

• And that curiosity alone leads me to view nuclear in a different way. Nuclear is essential. It's the future and it will be the main source of energy to all of us. Yes, I admit we have other alternatives to generate electricity; photovoltaic solar power (PV), hydro-power, biomass, wind, geothermal and wave.

• But one must realize, these source of energy are not available to every country. They are limited only to the lucky ones. Taking Malaysia for example, we can only use solar, hydro-power and biomass. We are not located in Pacific Ring of Fire region so geothermal is out. Wind is not constant and strong enough to turn the turbine blades since the country is surrounded by neighbouring islands and mountains. With no wind, of course there will be no waves.

• What about solar? Here in Universiti Tenaga Nasional (UNITEN) we have 3 PV panels for that and guess what? The panels are supposed to generate 3kWh but our panels can only produce around 1-2kWh even when the sun is shining brightly. Surely, many factors contribute to this. The panels might not be efficient enough. Plus we have high humidity, clouds, rains and no sunlight at night; they affect the energy generation.

Nuclear FAQ

Cherenkov Effect (the blog) has discussed much on what nuclear is all about so this time I'll try to explain some misconceptions regarding the matter:

Nuclear power plants produce harmful radioactive waste while other forms of electrical generation do not.

Mining for coal brings uranium to the surface of earth. That radioactivity can have a greater effect on the environment than nuclear waste. In fact every mining activity releases radioactivity from the ground to the atmosphere. We can't escape this.

Radiation causes cancer. Thus, it cannot be used to cure cancer.

Excessive radiation can cause cancer. However, utilizing the destructive power of radiation on cancerous cells can cure cancer. Radiation occurs everywhere. Read this article to lighten your worries.

Once a material is radioactive it is radioactive forever.

One can physically remove the radioactive particles from the material or wait for it to decay. Some radioactive decay in a short time while other decays might last longer than 10,000 years. 

Are current nuclear power plants unsafe?

Probably so. They were also build 30+ years ago with technology that was even older. We must not compare Fukushima's incident to the new to be build nuclear power plant. 

Can nuclear plants be built and run safely?

Yes. Every submarine and all but one Aircraft Carrier in the United States Navy is run by nuclear reactors. They are berthed at such places as San Diego, Bremerton, King's Bay, and Norfolk Virginia. In over 50+ years there has never been an accident or discharge involving contaminat­ed materials of any significant level -taken from comments here. 

Ok... Let's forget about coal and petroleum. Renewable Energy can cover the electricity demands. It's clean and it's the future.

By 2030 the world energy consumptio­n is going to grow by 50%, renewables alone are not going to cut it especially because right now they're contributi­on is in the single digits compare to 20% of nuclear -taken from comments here. 

States and locales that don't have the wind for windmills, or open space for solar will be forced to burn or buy from elsewhere. Transmission of clean power into these regions will be required to stay clean, even though transmissi­on too has its dirty impacts. Environmen­talists need to be open to this logic, and show a willingnes­s to compromise for the lesser of the evils, and not block the cleaner alternativ­es because they are not perfect.

Malaysia is rich with enough water dams to run the country. We have Bakun dam. More possible sites have been found too.

Indeed. We are blessed with enough rains and rivers to set up hydro-power plants. The question is, are we willing to sacrifice the forest to build one? A big area is needed to hold the water for the dam. Villagers and animals need to be relocated to another area. Bakun dam can produce 2GWh of energy which is enough for Borneo island consumption. 

But we have to understand the possibility of connecting Peninsular and Borneo. Construction cost of building underwater cable can reach up to RM 12 million per kilometre and the cables will be laid across our neighbouring countries. Political views might interfere the process. 

The cost to build a nuclear power plant is too expensive and takes too much time. 20 years to build.

So do with other power plants. The current power supply is enough for now but we're not sure about tomorrow. We are living in a modern world, we use smartphones and advanced computers everyday. The plan to build nuclear power plant in Malaysia is to ensure the stability and constant supply of electricity in the future.

Haih.. I'm not really sure about this nuclear technology. I'm afraid about the consequences. Who knows what might happen?

So am I and all of us. We can't escape the risk. In fact, other energy power plants share the same fate too. Every action comes with consequences. What we can do is to explore and study the options carefully (when I say carefully, I mean in every aspect, theoretically and practically). We have the best engineers, let's put our faith in their hands. Join forums and discussions about nuclear power plant.

Learn the facts, be relevant and reasonable. Have an open mind.

Nuke Fact #3 9:00 AM

Hello ! I’m back with latest info grafic! This info grafic will conclude three major nuclear accident in world history which is, Kyshtym, Chernobyl, and Fukushima.

The time interval for each accident is quite a duration. Plus they are also still running with old design. Get knowing about the new design and you will know how modern nuclear reactor looks like. Not even a plane can crush it.

Bill Gates join hand with China for New Nuclear Reactor 11:55 PM

picture by goocleantech.pcmag.com

Bill Gate who is Microsoft Corp. co-founder is looking forward in develop new kind of nuclear reactor with China. On the talk at China's Ministry of Science and Technology, Gates said the new type of nuclear reactor going to be very cost low, very safe and generate little waste. He add that no need human action to remain save all the time since these new type design take safety to a new level. In this project, Gate funded company , TerraPower will be working with China to develop the technology that cost $5 billion for research and development in next 5 years. The claimed was confirmed by Sun Qin, the general manager of state-owned China National Nuclear Corporation(CNNC) in last week media.

This join hand will enhanced the growth of nuclear improvement especially in safety aspect and waste issued. Moreover, Bill Gate had vision in alleviate poverty by this cooperation. He pointed that nuclear technology can benefits the local people into alleviate poverty and growth the economic barrier. Nuclear not as bad as people thought. Nuclear can strengthen the economic, build up social life and create international relation among country. A package of superiority comes with nuclear technology. It is win-win situation for local people and also nation itself.

Lets view the nuclear as opportunity not a threat. Realize the positive impact it could brought instead asking for radiation leakage. Change the usual thought so the benefits can be experienced. Think wisely before judging as what Bill Gate do now.

Greenpeace in France spread "Safe Nuclear Power Doesn't Exist" 1:39 AM

by en.tangrinews.kz.

5 disember 2011

France nuclear reactor Nogent Sur Seine, 95 kilometer from Paris was intruded by Greenpeace activists on Monday. They aims is to review the safety measurement of nuclear reactor. The activist success on breaking Nogent sur Seine clearly validate that safety precaution by France authorities narrow on possible natural disaster and not human factor.

The safety installation in nuclear power plant was too vulnerable and Greenpeace activist show how easy to get in nuclear heart hence unfurled a banned saying " Safe Nuclear Power Doesn't Exist" on the doom of one reactor. They also manage to paint danger sign on the building on the roof of one reactor. 4 activist involved in these nuisance was arrested by police.

picture by news.yahoo.com

These act was irresponsible behaviour and could danger them self. However, their intention for evaluating safety and security measurement have raised question and doubt on security system in nuclear power plant. Now, the news has spread and France nuclear reactor will struggling to perpetuate their existent.

Socialist candidate Francois Hollande has agreed a deal with the country's Greens to push to reduce France's reliance on nuclear energy to 50% by shutting down 24 nuclear reactors by 2025. As all aware, France is the country that most relies on nuclear energy with 1/3 France power comes from nuclear energy.

This incident was not their first move. They had done this before in Belleville nuclear power plant 3 years ago. Let watch the video in Belleville sur Loire, France on 27 march 2007.

Nuclear activists create drama in Germany 4:23 PM

,

picture by www.voanews.com

25 november 2011- thousand of activists swarmed the track along the train's final destination in Dannenberg, German. Protesters claimed that the waste transports could endanger the environment and population if there were to be an accident en route. There are pictures resemble the day drama on the day of Greenpeace which support the peaceful protes condemned violence along the road train from Areva facilities, France to Dannenberg, Germany before unload onto truck for final 20 kilometer leg of the journey by road to the Gorleben storage facility on the River Elbe. The transportation is important to repository the nuclear waste. The trains was late leaving Areva nuclear processing facility near Normandy on Wednesday because police clashed with hundred protestors trying to stop it in Valognes. Police fired tear gas and used batoon to keep protestors from occupying the tracks.

picture by www.voanwes.com

France has forecast this activist will swarmed Germany when the trains enter and alert Germany on the activist activity. Therefore, Germany has deployed 19, 000 police officers to secure the shipment in Germany. The reason of this protest due to the adverse event if there are accident on the route. However, this protestors whose claimed themself as Greenpeace already cross the boundary by condemned violent instead of peaceful protest.Their behaviour can create a dangerous situation to the public and themself.

In fact, the trains path suppose to be restricted due to the potential radiation and hazard that can be exposed by the waste nuclear. Can you imagine if there are lunatic anti - nuclear do some aggressive action such as throwing small bomb, stopping the train, and other crazy behaviour that can merely cause severe incident. Just look at the peaceful protest they claimed to have which turn into violent action. They cannot guarantee for their union actions! These counteraction can be beyond control. They should just let the waste nuclear had a safe journey to the Gorleben. This is more better for everyone and the danger can be avoid.

LET THE TRAIN HAVE THEIR SAFE JOURNEY!

News: Japan Halted New Nuclear Reactor 11:17 PM

FIGURE 1: Japan nuclear reactor current status by www.nuclear-org.co

On 1 disember 2011, Dailyonline Yumiuro reported that TEPCO is giving up new reactor at its Higashidori plant in notherm Japan due to financial difficulties after Fukushima crisis.. In fact, no companies have publicly announced they are giving up construction of planned new units. Therefore, TEPCO denied the Yumiuro report. The new nuclear reactor however, expected to start operation in March 2017 but been halted following the radiation crisis.

Currently Japan having issued with new energy policies. Japan Prime Minister predecessor Naoto Kwan, vowed Japan to off nuclear power and calling for a review of plans to boost nuclear capacity to meet over half of electricity demand by 2030. With nuclear reactor shut down for further inspection make Japan leak of power supply which is currently having 1/3 of maximum capasity(maximum=49, 110 megawatts). Only 16 reactors are running while other undergo a regular check up every 13 month.

The rise of nuclear radiation is now bring Japan in the tough road. They on the way on proposed new alternative which is renewable energy to replaced nuclear position. Some how this renewable energy cost higher price compared to nuclear. So, can Japan manage to pursue their effort in blocking nuclear energy by transform their energy production toward renewable energy with rise of electricity price? Do public willing to pay more which is double than current price ? It is an typical question to ask when it come to money. I think Japan need to overview their plan deeper and details to avoid troublesome in future.

Iran taking step to Nuclear Weapons 8:47 PM

q,

figure 1: typical implosion nuclear bom by www.nytimes.co

Iran post threat with it secret facility of producing nuclear bomb. Currently Iran is on the way to build enrichment facilities. From the facilities, their secretly build nuclear weapons. American and European officials believe Tehran is planning to build nuclear weapons. Iran's leadership says that its goal in developing a nuclear program is to generate electricity without dipping into the oil supply it prefers to sell abroad and provide fuel for medical reactors. The actual reason behind this nuclear bomb is:

• Iran scared of the fact that 5 out of 9 world's nuclear power are nearby or on its border
• Iran adopt nuclear hedging (protection security) by maintaining nuclear weapon as option to remain with nuclear treaty or agreement.
• attempt to become more self-reliant in arms and technology facing Iraq which has chemical weapon and nuclear weapon program.

picture of Mahmoud Ahmadinejad by www.theglobeandmail.com

Myself believe that Iran just trying to survive from nuclear threat from the border countries such as Iraq. The middle east country continuously post nation threat and create most of political issued by launching missile against them self. In order to survive, Iran choose by developing nuclear weapon. It is understanding if Iran just want to protect itself from being nuclear victims. However, their act toward nuclear weapons is not a correct ways in gained a solutions. This can lead more disasters than the solutions. Hence, nuclear bomb should NOT be a SOLUTION! Even Washington against Iran for developing secret facilities for preparing nuclear bomb. It is a fear to world security. Therefore, I against the Iran for nuclear weapons! Nuclear weapon does not solve anything but it can create WAR.. WAR..WAR people. Who knows maybe it can lead to WORLD WAR III..

Mixed Thoughts About Malaysia NPP 7:00 PM

Our government is trying to spread little by little about going nuclear in the future years. Many oppose as expected, although there are some agree for whatever it is, provided the energy is cheap. So I stumble upon a thought from our citizen about the matter. She's totally objecting nuclear and in her blog she questioned about;

1) Why are we throwing out so much money and expertise on a fuel that produces so much heat, which will requires a lot of water to cool it off, thus adding up to the lack of water for agriculture and basic utilities?

2) Why spend money on a fuel that produces a whole lot of toxic waste that we still don't know how to dispose without ever poisoning our land and our people?

I may be in the process of learning nuclear and how the plant works. But I will try to explain this matter from my point of view, with some help from what I've learnt in class. They are as follows;

1) Heat from nuclear power plant is never going to affect the agriculture and basic utilities. Here in Malaysia, we are surrounded by sea and yes, the sea water is one of the option for reactor cooling. To do this, the sea water (salt water) will be purified first before being used as a coolant for reactor cooling. After cooling is done, the water will be released to a reservoir. In our case, the sea nearby will become the reservoir. Unfortunately, no living creature will be able to survive the heat. This will happen to any energy power plant that uses sea water as coolant and reservoir, not just nuclear power plant.

2) As for the nuclear waste, it is nothing like the toxic waste we often see in the television. Uranium fuel will be recycled or reused for several times to its maximum point. To dispose, the uranium waste will be sealed properly and being transported to certain places which has no living things. The multiple barrier concept will be used too. Problem may occur when it comes to transporting the nuclear waste to the disposal area, no guarantee about the safety of the whole journey. The ultimate disposal of vitrified wastes, or of used fuel assemblies without reprocessing, requires their isolation from the environment for a long time. The most favoured method is burial in stable geological formations some 500 metres deep.

I will go into details with nuclear waste management in next post. Thank you

References : http://www.world-nuclear.org/education/wast.htm

Comparison Of Fossil Fuel and Nuclear Power 1:00 PM

There are lots of resources in generating energy to power up our daily live. The increase in the demand of energy has put a lots of challenges to fulfill the required needs in the century. Lots of consideration and comparison has been done to gain knowledge in generating energy. The table below are premised on the assumption facilities run with reasonable attention to environmental protection so far as routine operation and concern of waste management.

Table of comparison between Fossil Fuel and Nuclear Energy

[click table to enlarge]

** Question has been raise about the effect of krypton- 85from extensive reprocessing necessary for a breeder reactor system  on  cloud formation and hence potential climate change. However krypton- 85 can be removed from exhaust gases by cyrogenic cooling.

Further explanation and source at Institute For Energy and Environmental Research

Malaysia's Options for Power (Part 4) 8:30 PM

Biomass

Issues

• Small scale and intermittent - not enough to materially provide security of supply (not constant)
• Economically unattractive
• Wind - we live in a low wind speed region
• Biomass - fuel supply and transport issue

Possible Solutions

• Systematic promotion with proper policy and incentives for viability from government
• Focus on developing mini-hydro, solar, biomass and biogas
• Need feed-in tariff

Biomass helps to reduce landfills hills by reprocessing the waste to become biofuel. This biofuels will be burned to heat water and generate electricity, yeps the typical process of power generation. The problem with burning carbon is the product will be carbon dioxide gas. Don't forget the smokes too.

During our Renewable Energy lecture, we learnt that biomass suppliers (mostly palm plantation companies) prefer to sell their product to outsiders instead of generating their own power plant. It is more profitable of course. Same applies to our petroleum, remember?

To conclude things up, all I can say is, we have to sacrifice something in order to gain something unless we want to go back to the old days. I need my smartphone. I need my computer and of course I want to travel around the globe with ease. Think about it.

China will grow larger 9:00 PM

While we are still looking into nuclear as energy sources, China - a big player in both energy and economic power take a large step to go ahead with nuclear. Their target consist of three stages :-

• by 2030 - Fast Breed Reactor (FBR) in combination of Pressurized Water Reactor (PWR) will produce 200GWe
• around 2050 - combination of FBR and PWR output are expected to be doubled up to 400GWe 
• by 2100 - full replacement of fossil power plant and electricity are generated by means of nuclear plant instead. The expected output is 1500GWe

To achieve this target, China are looking into some new experimental design like Chinese Experimental Fast Reactor (CEFR) which utilize fast neutron instead - which means neutron doesn't need to be slow down first to achieve a controllable reaction and desired power output like Generation II and III reactors. Some other alternative reactors that China still looking into are:- 

• Chinese Demonstration Fast Reactors (CDFR) - similar to OKBM Afrikantov design. It uses ceramic MOX pallets fuel (breeding ratio of 1.2).
• Chinese Demonstration Fast Breed Reactors (CDFBR) - uses U-Pu-Zr fuel which has higher burn up and breeding ratio of 1.5. These are Generation IV reactors. 

Credit image goes to Xu Mi, Chief Engineer at CIAE : “Fast Reactor Technology Development for Sustainable Supply of Nuclear Energy in China (slide presentation)

So, looks like China is one step ahead to achieve a higher score in never-ending global energy race. With it's current economic growth, energy hunger on such a large scale is already expected. Let's hope we can catch up fast. 

 

You can read more at : Summary of China's fast reactor programme by BraveNewClimate.com

Malaysia's Options for Power (Part 3) 8:30 PM

Peninsular Hydroelectric

Issues

• Remaining hydro resources are small (1725MW) and mainly for peak hours (2-3 hours operation a day)

Possible Solutions

• Developing Hulu Terengganu (250MW) and Ulu Jelai (372MW) to commission in 2013/2014
• To develop multi purpose scheme of Lebir and Nenggiri for flood mitigation, power etc.
• To systematically develop the remainder hydros

Peninsular's rivers are not big, maybe just nice for mini-hydroelectric dams. It's not enough to cater the needs, even our biggest hydroelectric dam, Bakun, can only generate 800/1000MW. TNB has to supply 15 000MW to Malaysians. Where to get the remaining?

Renewable Energy (RE) can be one of the alternatives to choose from but remember, we have to diversify our energy sources. RE power plants do not give much power either. We rely too much on coal and petroleum for the past few decades. It's now time to take action from our mistakes.

Malaysia's Options for Power (Part 2) 8:30 PM

Coal

Issues

• Over reliance on coal (40% of country's energy source)
• Supply risks (availability and politically)
• Price risks including FOREX
• Scarcity of suitable sites for future coal plants
• Environmental & climate change regulation

Possible Solutions

• Continuous strategic coal procurement
• Diversification to other sources of generation
• Strategic investment in coal mines
• Use of advanced technology to optimize and increase efficiency

Truth is, we don't have much coal. Yes, we have coal mines but the supply can't keep up with the demands. Thus we have to import from outside (Indonesia 72%, Australia 15%, Africa 13%). The price for coal is not the same every year. It fluctuates and of course it won't go down. That is if we are not troubled by politics or currency crisis. In 2010, our import is doubled from 9-11 million tonne to 19.9 million tonne. 

Burning coal is already bad for environment and yet we are burning money to charge our gadgets.

Malaysia's Options for Power (Part 1) 8:11 PM

Natural Gas

Issues

• Demand exceeds supply
• Depleting local gas supply
• Power sector gas supply uncertain beyond 2019
• Gas price not reflecting cost of supply - lack of incentive for new supply investment

Possible Solutions

• Further gas resource development from marginal fields and import of gas from Indonesia, JDA etc.
• Reconsidering of benefits & costs of future piped gas export to Singapore
• More sustainable basis for allocating gas for power & non-power sectors
• Leverage on Liquefied Natural Gas (LNG) terminals being built by Thailand and Singapore
• Development of LNG regas terminal in Peninsular Malaysia
• Remove subsidy gradually

When there's fuel, there's natural gas. Petronas has warned us about petroleum reserves which will dry out by 2020. The production will decline 10% each year. What will happen by then? Yeps, we have our own oil but since the grade is high, the oil is being sold to other countries. Of course this comes together with certain contracts (with Japan for example is 20 years).

Someone may mention about using palm oil as alternative. Same thing. Selling the oil is more profitable than using it for power generation. As always.. money comes first. Not everyone is willing to sacrifice for the benefit of all. Not yet.

Largest Explosions In Modern History 3:30 PM

First time when I've heard about nuclear is when someone mention nuclear bomb. And that phrase "nuclear" poked my interest to look into few largest most destructive explosion ever recorded in human history.

• Simple math and facts (in tons of TNT)
• Little Boy – 13 to 18 kilotons (exploded at Hiroshima during World War II)
• Fat Man – about 21 kilotons (exploded at Nagasaki during World War II)
• Tsar bomb – 50 megatons (most powerful nuclear bomb ever detonated). A three-stage H-bomb uses a fission bomb primary to compress a thermonuclear secondary, as in most H-bombs, and then uses energy from the resulting explosion to compress a much larger additional thermonuclear stage. It compromise of 3-stages which resulted most powerful nuclear explosion man ever made. 
• Krakatoa -  this one is not man made of course! But the explosion is considered to be the loudest sound ever heard in modern history (heard over 4,000 km away). The eruption was equivalent to 200 megatons of TNT. The volcano exploded in 1883, it killed more than 40,000 people.

Apparently mother nature rocks! Don't you think so? Here's a video of Tsar Bomb explosion.

More info here: Krakatoa, Tsar Bomb, Little Boy, Fat Man