DRAMA WHICH WE DON’T WANT TO SEE...!!!

During the contract awarding phase for our 1^st NPP, everyone seems happy, positive, and optimistic. The team started huge. Everyone wants their slice. Everyone is happy to gain profit.

Halfway during the construction of our NPP...As problems emerge and tension rises,the team gets smaller.



During the operational phase, things got wild and out of control.

We wish and hope for continuous support from every Malaysians to make sure that our  NPP is an engineering marvel. 1 MALAYSIA!!!

BLOG SUMMARY

I’ve received several complaints saying that they want to read but they don’t know which post to read. Also several questions were asked repeatedly. Hence I decided to help out by posting a synopsis on several posts I’ve made so far.

·      If you are interested to know what are the desired condition to run a nuclear reactor in physics which is reactor criticality state, please read post entitled = class on 28^th September.....Posted on 29/9/2010

·      If you want to read a soft article (light and easy) on Chernobyl incident, please read post entitled = Chernobyl.....Posted on 29/9/2010

·      If you want to know in depth about Pressurized Water Reactor condition, please read post entitled = Why we don’t want a moderator to boil in a PWR.....Posted on 30/9/2010

·      If you are concern about can Malaysia run a NPP, green energy, and applications of renewable energy such as solar, wind, tidal, and geothermal in Malaysia, please read post entitled = Topic B for 30^th October.....Posted on 1/10/2010

·      If you are interested to know what factors that affect stability (desired condition) of reactor, please read post entitled = Class Summary on 5^th October 2010.....Posted on 6/10/2010

·      If you are interested to read in details about Chernobyl in terms of Xenon and reactivity, please read post entitled = Chernobyl Continuity.....Posted on 6/10/2010

·      If you prefer myth about radiation in Bandar Baru Bangi, please read post entitled = Topic 13^th October 2010.....Posted on 13/10/2010

·      If you want to know why people fear NPP, please read post entitled = Topic 14^th October 2010.....Posted on 13/10/2010

·      If you want to have an Idea of where is it suitable to build NPP in Malaysia and how far can a radiation travels, please read post entitled = Nadia Aaron asked.....Posted on 16/10/2010

·      If you want to know about safety concerns related to NPP, please read post entitled = Final Class Review: Things that you might want to know.....Posted on 20/10/2010

·      If you want to know about Nuclear fuel and waste management, please read post entitled = Nuclear Fuel and Waste.....Posted on 26/10/2010

Owh owh I’ve just realized that I had actually post a lot. No wonder people argue they are lazy to read it. For additional information you could read recent updates and also older post. Please do not hesitate to post comments even in the old posts as we check it regularly. Your comment is most welcome and we value it. Apparently our readers are knowledgeable thus this blog seems to self sustain even when we are not around. Readers, please pursue your knowledge in Nuclear Power Plant. Don't stop here. You can use it to score in MEHB513, or propose for your Final Year Project, or for your post graduate studies, or even a wealthy carrier.

Nuclear Fuel and Waste

Regarding waste management, I can assure you that it is tedious and I would prefer pass my notes to you rather than posting it here. As how paranoid the safety implementation in a NPP, same goes with its wastes. They created a standard codes to build virtually an indestructible “dustbins” and I’m not joking or lying. Then these “dustbins” are buried deep in the earth within a fortress of thick concrete. Again I remind you, Malaysia agreed to NPT or NNPT which means that IAEA will stuck their nose in this matter as well if we have a NPP (Read post entitled: Things that you might want to know.....Posted on 20/10/2010 for IAEA and NPT or NNPT). That’s why I prefer buying the complete package offered by the Russians -They design the NPP, they build the NPP, we run the NPP, and they take back ALL of its waste either from building phase, assembly phase, operating phase, and even depleted fuel. - This is cheaper considering we only need one NPP and the waste is small rather than we have to build an underground fortress and indestructible “dustbins” which complies with the strict paranoid standards. We only require one nuclear reactor in Malaysia so cut the chase and buying is more reasonable solution.

Regarding Nuclear Fuel. In Malaysia we have no Uranium discovered yet for mining. Even if we have our own Uranium source, by nature it is 99.3% Uranium 238 which is fertile and 0.7% Uranium 235 which is fissile. We want to have fission means that we prefer fissile which concludes that in a block of rock containing Uranium, only 0.7% is the one we want. So here comes the processing part which is called enrichment. NPT or NNPT remember? Enrichment needs to abide the NPT or NNPT article. I prefer not to explain further as it is not feasible in Malaysia. Better we simply buy it rather than producing it. Why? In Russia, there is a NPP with 4 reactors. Guess what? 3 of the reactor are used just to empower the enrichment plant using gasses diffusion process. Imagine up to 3000Mw. We only require one nuclear reactor in Malaysia so cut the chase and buying is more reasonable solution. In addition, 95% of depleted fuel can be recycled to produce MOX fuel. Uranium from mining is called Yellowcake before convert into HEX fuel.

Transportation of either nuclear waste or fuel abides the same extremely safe standards designed by the experts nuclear industry. Yes again, it might sounds like paranoid. Let me give you a clue, you have to construct a ship designed specifically for transportation of nuclear waste which I had mentioned just now being placed in an indestructible "dustbins".  Russian package includes transportation and thus we can lay our hands of this matter.

I do apologize if this post is less informative as I personally think this matter is not suitable for most Malaysians to know in depth. But obviously it is extremely important for Malaysians who are keen to join this industry.

Faradilla asked...

Is it possible to built NPP in Malaysia? Do we have expertise in this field and how about the cost to have NPP?? It’s very expensive.What a waste rite??

I've mentioned some regarding this matter in my post entitled Topic B for 30^th October.....Posted on 1/10/2010. Maybe you could spend some time to read through my posts. We don't have the expertise to build our own NPP, same goes to most other countries. Out of 30 countries with NPP, 60 considering or building NPP, only 5 countries have this expertise. The game plan works this way, we buy the NPP then we run it on our own. Though not yet an expert, we do have sufficient knowledge and expertise to operate one.

As for the cost, to build one costs between 1 to 3 Billion USD (RM 3.5 Billion to 10.5). If you draw a cash flow diagram for NPP, even if you only consider useful life to be 40 years, NPP would emerge as the undisputed champion. If you have no idea of how a cash flow diagram works, MARR, IRR, ROI… does it rings any bell? If not then put it this way. Spend RM150,000 to buy a Honda Civic Hybrid or RM80,000 for a Honda City. Comparing both in terms of fuel consumption with same usage rate for 20 years and the Hybrid would be the champ. NPP is expensive in terms of its initial cost but its production cost; say for 1000MW of power, it requires 1km² of land area compared to 100km² of Photovoltaic Solar Panels. Hence it is the cheapest and cleanest compared to any other power production method.

UNITEN students should be aware that our upcoming Solar Ranger 2 plans to use the best PV solar panel which costs roughly rm350,000 for 1.2m² (Price is ONLY for PV solar panel. Exclude inverter and battery or everything else) so if anyone from UNITEN tries to argue saying PV solar is cheap, please join the Solar Ranger 2 crew by contacting Assoc Prof Dr Azree Idris, or Mr Zafri Baharuddin, or Mr Mikhail Fong Abdullah, or Assoc Prof Ir Dr Hanim Salleh. Forgive if i'm wrong but I can assure you that my figures are close.

JASON FRANCIS asked...

I'll try to represent my team to answer these questions. I'll answer in accordance to my understandings. Hope it would be sufficient.Is it possible to revert global warming and climate change?
No one could say 100% sure though it might be possible to revert back but it is 100% sure that it won’t worsen. Truth is emission of Green House gases in area with relative humidity in excessive of 60% such as Malaysia has almost zero contribution towards global warming.

The problem is that at our current rate, earth temperature will increase 2 degrees centigrade within 15 to 20 years from now and this could increase probability of species extinction. What scientist had recently discovered is that there are massive amount of methane hydrate lying on our sea bed. If the earth temperature increases by 6 degrees centigrade, this frozen methane could melt down and released to our ozone. The effect is 5 to 10 times more compared to other greenhouse gasses if I'm not mistaken. That's why it is important for humans to drastically reduce the production of green house gasses by any means whereby the major contribution is from transportation (22%) and energy production (16%). Looking at the ever increasing energy demand, nuclear is the most efficient and significant way to achieve it without sacrificing our leisure comfort style of living.

Final Class Review: Things that you might want to know

First of all, I would like to emphasize that my previous post said that “rumours said that it would be build in Negeri Sembilan”. See the word rumours there? Besides, I’m quite sure our government is keen to build it at least 20km radius away from residential area or otherwise they might lose in the next general election.

A lot of people keep asking the questions related to NPP safety issue. The truth is it is better for you guys to concern on road safety issue rather than NPP. My classmates had done an amazing job posting stuffs related to safety and thus I believe most of you already knew the facts such as 5 layers barrier which consists of the uranium fuel pellet ceramic shell, zirconium fuel cladding, 20cm hardened steel reactor pressure vessel, 4cm steel sheet containment vessel, and  1 meter thick concrete containment building. Even if a plane crashes into it, the worst case is that ONLY the 5^th layer which is the 1m concrete containment building got damage.  

Some people questioned why use an aircraft as an example? What if someone drop a nuclear bomb instead? This is because if someone dropped a nuclear bomb, you might concern on the nuclear bomb itself rather than the NPP. Nuclear bombs have over 90% of uranium enrichment whilst NPP have only 3%. What about earthquakes? What about tsunami or tornado or other natural occurrence disaster? NPP is built directly on the rock stratum which means at least around 50 to 100 meters below ground level. Still can’t get the relationship? Earthquake tremors in the subsoil which is the ground level are 2–3 times greater than tremors in the rock stratum as the weak structure of the subsoil amplifies earthquake tremors. In addition, Low centre of gravity also means better stability. For further understandings, you could read on mechanical resonance and couple harmonic resonance. It is actually proven that natural occurrence disaster is like an ant pinching your toes for NPP by looking at Japan, a nation well known as earthquakes and tsunami prone. In addition, United States of America with its hurricane or tornado prone.

Ok enough on the external part. If you take a look into the internal part, you might say that these guys who designed the NPP are more than paranoid. I believe that there is no need for me to mention it in depth so I’ll give some simple example. Instead of 1 pump required to safely operate the reactor, there are 2 more pumps available for use in case of emergency. But pumps normally run on electricity, what if the electricity fails? Then comes the auxiliary power, 4 diesel generator placed in two different building is available to manage this issue. Then what if there is insufficient water supply? Then we have water supply from at least 2 different sources. If the reactor overheats, then we have the emergency core cooling system (ECCS). You can read it from my classmates’ blog if you wish to know more on ECCS. As for me, I’ll stop here. What I can conclude is that for the reactor safety, every possible threat is considered beyond possibilities. They plan for the worst but expect for the best. This includes the fuel and waste management.

Here comes the best part. Some people quoted “I know that everything is done and maintained at extremely high standards, but that is for developed countries. I’m not convinced with Malaysia”. The best thing about NPP is that actually you don’t have to trust your government or even your own people (if you prefer not to) for this case. Malaysia is had signed The Treaty on the Non - Proliferation of Nuclear Weapons or also known as Nuclear Non-Proliferation Treaty (NPT or NNPT). You could read the treaty for 2005 at

http://www.un.org/en/conf/npt/2005/npttreaty.html.

You could even search elsewhere if you prefer. This means that we are and never will be alone. We have almost the whole world working together to ensure NPP safety as for them “one accident anywhere means accident everywhere”. The International Atomic Energy Agency (IAEA) will closely monitor and inspect everything related to nuclear in countries that had agreed on NPT or NNPT. Fuel waste management... There is a shortcut to overcome this matter as the Russians offer a complete package. They design the NPP, they build the NPP, we run the NPP, and they take back ALL of its waste either from building phase, assembly phase, operating phase, and even depleted fuel. Which reactor is not a great deal. Basically all we need to do is get most Malaysians to agree, equip our citizens with basic knowledge, develop more expertise in this field, and pay around RM3.5 billion initial cost.  Don’t look at that RM3.5 billion.... Recently our government announced RM12 billion for solar energy development which is more than 3 times the amount for the NPP.

nuke_2010.wmv

Nadia Aaron asked...

Where is it going to be build in Malaysia?

If our neighbouring countries had a NPP reactor blow, will the radiation reach us?

Where to build? Borneo (Sabah or Sarawak)... Not a chance. There's already BAKUN over there to supply electricity. Well not yet but sooner. Ok, suppose our NPP is built in Borneo, how are we supposed to send the electricity to the peninsular where the demand is at peak? Transmission cables ya... Distance more than 1000km so we should use underwater sea cable. Can you imagine how much power loss will occur within 1000km cable? Suppose we increase the power. P=VI. Increase voltage? Not a chance. If there's a leakage then imagine 1000V or more in water. Increase current. Possible but high current flow would produce a strong electromagnetic field around it which could damage the eco system. Perhaps my colleague taking EE could explain more on this as it is neither my expertise nor preferences. It is actually not possible to do such a thing for now. Even if we manage it, the cost will be too high hence leaded to loss rather than profit. Profit (loss) = Total Revenue - Total Cost. I actually heard rumours saying we already have a spot for our NPP. It should be near the sea for the cooling loop system and easy transportation. Not around north east coast (Kelantan, Pahang, Johor, Terengganu) as it will be too "exposed". So the nominations are Penang,kedah, Perlis, Selangor, Perak, Negeri Sembilan, Melaka, and Johor. Owh ya Penang, Kedah and Perlis have a Tsunami history and hence can be excluded. Melaka also as its sea shore are too dense. I think the rumours stated Negeri Sembilan.

Radiation could actually be transferred in almost every possible way you could think of. It only depends on its intensity, shielding, and distance. Chernobyl incident occur in Ukraine, Europe. In several days, the United States of America detected that the radiation reached them followed by Japan. That’s just a simple indication on how far and how fast it can spread. It actually depends on the source radiation intensity where the intensity decreases as distance increase. We are talking about Indonesia and Thailand.

Thank you for your question. A good one actually. Thanks for everyone who had been reading this blog. Thank you all for your precious comments. We do appreciate it but please read through all article posted in this blog before asking as some questions were asked repeatedly. I know it’s kind of boring but that’s why I said just read through or even glance through . Thank you.

Topic for 14th October

How am I suppose to expect readers to get excited with my posts if even myself thinks it's boring. Never mind, people differs in taste and preferences.

Thoughts for the day

We live in a world full of lies. Great people are the ones who can tell lies yet no one can deny. The greatest people are those who can tell lies, not only you can’t deny it but you agrees with it. You can meet most of these great people in the political and business world.

Some example is that how you felt safe when boarding an airplane or when you drive a Volvo or how you felt secure saving your money in a bank.

The truth is that there is nothing in this world that you could say 100% safe yet you choose to be deceived in order to live or otherwise you’ll live in paranoia. The world is harsh. Concluding all the above, Malaysia needs a spokesman… A great one that could deceive us by saying NPP is 100% safe.

Malaysian government concerns about the citizens fear of NPP. Why fear?

Humans by nature fear something that we can’t truly understand, predict, nor control. We don’t fear nuclear power plant (NPP) but its radiation. Why is that? Nuclear scientist and engineers understands about radiation. They also can control and predict it within some limitations so why fear is still creeping? Because it is something that we can’t hear, neither smell, touch, feel, nor see. It’s a mystical killer that we can’t comprehend with.

So if we want to build one, we have to find a way to reduce or even eliminate fear among Malaysians. I suppose that if our government provides each house with a radiometer, then the fear could ease of. With it, people thought that they actually have some senses to detect radioactive. Or even build a 1 meter thick concrete fortress for each residential area in case of a nuclear reactor blows, well that’s paranoid actually. The thing is our neighboring countries (Thailand and Indonesia) are seriously considering having a nuclear power plant (NPP) by 2025. Say the worst that you fear occurs to their NPP, and then we will still be affected by the radiation leak even though we don’t have one.
What we need is some optimistic whereby our leaders can set a good example and influence Malaysians by living in the closest residential area where the NPP is built. If a nation that had been struck by 2 nuclear bombs could still appreciate NPP, then it’s time we learn from them.

All I'm saying is my personal thoughts. No hard feelings.

Topic 13th October 2010

Sorry to consolidate several posts in one go (dated 13^th October) as I will be extremely busy for the week and maybe for the upcoming weeks as well due to my Final Year Project.  It’s been a while since my last post and before this all my post are quite lengthy with some technical information blended together. In fact I hesitate on anyone out there who actually read it. This time I’ll make my posts light and easy. Said that before… As my colleagues had done some interesting job posting pure facts and technical information, today I would post some general issues and nothing much on technical information. (Excuses as to be honest, currently I am lazy to use my brain and hence I wrote down spontaneous thoughts).

Is it myths or fact?

I’ve heard this ever since I was in primary school. Universiti Kebangsaan Malaysia (UKM) has the highest rate of staffs diagnosed to have cancer in Malaysia. They believe that it had something to do with Malaysian Institute of Nuclear Technology (MINT) which is located less than 20km away from UKM. If MINT is emitting substantial amount of radioactive, why didn’t their employees suffer the same consequences? Ask staffs in UKM and their answer would be “people working at MINT are equipped with sufficient protective gears to reduce radioactive exposures while UKM staffs have none of these”. It absolutely makes sense.

But remarkably when you look deep into residential area around MINT (Bandar Baru Bangi, Teras Jernang, Bangi Lama,etc), the statement doesn’t make sense. The numbers of people diagnosed with cancer among these permanent residents are significantly low. They don’t have any protective gears or live in a 1 meter concrete fortress. Maybe electronic devices or any equipments or even the soil in UKM is the source of radiation, which is if you insist to put the blame on radiation.

Class on 12th October 2010

Topic covered today was related to nuclear fuel. We were supposed to do some research via internet about why did the price of Uranium dropped significantly around 1970’s but I am lazy to do some research on that so I guess I’ll put it on hold for now. You could read it from my clasmates' blog instead.

As a replacement, I would just like to nag a bit about this whole course. Here I go… A wise man once said that people who had never done any mistakes in their lives are the ones who actually didn’t do anything. The statement is not completely true from my point of view as we can actually learn from others’ mistakes as well. The truth is we do learn best from our own mistakes but unfortunately we don’t live long enough to do all the mistakes and learn from it plus some mistakes cost too much to bare and thus learning from others’ mistakes is the best alternative. Having said this, take Chernobyl incident as an example. It is a devastating event for the nuclear power plant industry and human history. But looking things from another perspective, the incident is a major breakthrough in nuclear power plant studies. Learning from others’ mistakes ya.

If our lecturer takes a week or 2 during lectures, telling the story of this incident in sequence then relate it to the physics in accordance with its sequence, I’m quite sure that most of the students would appreciate or even understand more on balance of reactor, multiplication factor, reactivity (reactivity coefficients, positive and negative feedback), Xenon poisoning, and control rods. Better than teaching some tedious derivation and mathematical formula which I could assure that most of the students won’t use it for the rest of their natural life. Well how much could we actually cope within 4 months right? It’s better to have a few sharp blades rather than having thousands of blunt blades in our kitchen. Meaning that; let’s not focus too much on learning a lot but learn a bit which we can easily explore in depth. The course syllabus and notes were carefully thought out which is why it is very comprehensive, everything is important, but it is futile if students can’t cope up well. Students can’t even answer general questions asked by the public related to NPP. After all it is an introduction class.

Please don’t get me wrong, this is my personal point of view. I did enjoy attending this course. In fact, it is an exciting course that I only went absent once (which is during quiz 4) in the whole semester despite its harsh schedule (6pm to 730pm even during fasting month). Again, for those who are planning to take this course, don’t change your mind after reading this. If the teaching method doesn’t suits me well, it doesn’t mean that it won’t suits you. The lecturers are quite reasonable, flexible, and very open minded. In addition young and talented (Sir please don’t deduct marks sir please…)

Exam on 11th October 2010 Overview

This is my personal experience which I would like to share. On the last Monday, all students taking Introduction to Nuclear Power Plant in UNITEN had to undergo an extremely harsh test. Topic covered consists more than 500 slides. Imagine how harsh it is just to read through and understand that much amount of knowledge. Not to mention that words used in the slides are technical (Nuclear Jargons). We were quite providential though as our lecturers allow us to bring in one personal cheat sheet per test session, which is quite a useful way to “force” students to read almost everything.

That’s not where it ends though; imagine having an hour and a half test, take a break for 30 minutes then continues for another 2 more hours (total duration including 30 minutes break is 4 hours). Gosh the last time I undergo an examination with duration exceeding 3 hours is when I took my Engineering Drawing exam 7 years ago. Imagine 4 hours answering all subjective questions. From studies, basically normal human brains could focus over 90% of its capacity for 2 hours straight and that explains why most classes were scheduled to be less than 2 hours for a subject, final examinations were scheduled to be 2 hour and a half where 30 minutes extra is actually time for you to squeeze out something from your brains and do some checking, a F1 regulations state that a race could only last for 2 hours max (Despite that exceeding 2 hours of race would leave the driver dehydrated and cause internal damages due to the G-forces exerted on them).

How does it feel… For the 1^st session of the exam, everything feels great. Having a cheat sheet in addition with my understandings, answering was a breeze but entering the 2^nd session disaster strikes. My brain refuses to generate the answers even though I actually knew the answer, my fingers starts to hurt and trembling reluctant to write down anything, my eyes starts to haze (or fuzz or dusky or dim or blur or glaze) reluctant to read the questions nor my cheat sheet, my body temperature starts to fluctuate causing perspiration even in cold …. My whole body was against me. Amazingly the questions set up nicely with the time provided.

Ok I think that describes my experience enough. For those who are planning to take this course, don’t change your mind after reading this. The lecturers are quite reasonable and flexible. I’m sure they will improvise their assessment method in the future. Having 50% objective, 20% structural subjective, and 30% essay might be better. This is my personal prospective and doesn’t speak for the team or the class.

Basic of nuclear physics......

History of nuclear physics

So here...I post again about the basic of nuclear physics....hope you guys can understand a little bit of it....like me also...

@ The history of nuclear physics is

*  The discipline distinct from atomic physics starts with the discovery of radioactivity by Henri Becquerel in 1896,while investigating phosphorescence in uranium salts. The discovery of the electron by J. J. Thomson a year later was an indication that the atom had internal structure.
*  In 20th century the accepted model of the atom was J. J. Thomson's "plum pudding" model in which the atom was a large positively charged ball with small negatively charged electrons embedded inside of it. By the turn of the century physicists had also discovered three types of radiation coming from atoms, which they named alpha, beta, and gamma radiation. 

@ So,there are the best things that we must know about the nuclear physics.
Nuclear physics is the field of  
-atomic nuclei
-nuclear power
-nuclear weapons
-nuclear medicine
-magnetic resonance imaging
-material engineering
-ion implatation
-archaeology
-radiocarbon dating 


For this reason,it has been included under the same term in earlier times.

So,

@ The atoms of which every element of matter is composed have a nucleus at the center and electrons whirling about this nucleus that can be visualized as planets circling around a sun, though it is impossible to locate them precisely within the atom. 

@ The nuclei of atoms are composed of protons, which have a positive electrical charge, and neutrons, which are electrically neutral. Electrons are electrically negative and have a charge equal in magnitude to that of a proton. 

And also,

What is the Nuclear (fission) energy:

•The Commercially established since 1956 

 Calder Hall, gas-cooled Magnox NPP at Sellafield (UK), 50 MW  (later 200 MW)

• and Today: ~16% of world’s electricity generation (18% hydro, 66% fossil)

• Switzerland: ~40% (nearly all the rest: hydro)

This is about the structure of the atom (Rutherford’s model):

• Mass concentrated in the nucleus (mH/me ~ 1837)

• Nuclear charge: +Ze (Z: atomic number, e ~ 1.6.10-19 coulomb)

• Quantum mechanical basis for atomic, nuclear structure

• “Classical dimensions”: nucleus ~ 10-13 cm, atom ~ 10-8 cm

Energy units (1eV ~ 1.6.10-19 J)is the :

- Binding energy of outermost electrons ~ order of eV

– Energy involved in chemical reactions ~ same order

- Binding energy of nucleons (constituents of nucleus) ~ order of  MeV !

– Energy in nuclear reactions 106 times greater than in chemical.

This is the Often encountered in nuclear engineering:

- Nuclear fuel, activation of materials, fission products, wastes

- Fundamental law: (λ : decay constant)

- Units of (radio)activity:

- 1 curie (Ci) = 3.7 x 1010 dis/s (activity of 1 gm of Ra226)

- 1 becquerel (Bq) = 1 dis/s

- Example: 1 mCi = 10-3 Ci = 3.7 x 107 Bq = 37 MBq

Binding energy is the Mass defect???

Let's talk about mass defect and binding energy.Im actually not that person who can write and post this confidently...but I can  try my best to share my knowledge with u guys....so be cool, no offence......let just start the party...

Binding energy is the mechanical energy required to disassemble a whole into separate parts.

So,

Mass defect is the difference between the mass of the atom and the sum of the masses of its constituent parts.

Then,  Binding energy is  the amount of energy that must be supplied to a nucleus  to completely separate its nuclear particles.

And,

Binding energy is the energy equivalent of the mass defect.

Also,

 Mass defect can be calculated by using the equation below. 

  

Dm = [ Z(mp + me) + (A-Z)mn ] - Matom 

  

So,binding energy can be calculated by multiplying the mass defect by the factor of 931.5 MeV per amu.

The reader's and followers....

It is possible to convert  between mass and energy. Instead  of  two  separate  conservation  laws,  a  single  conservation  law states  that  the  sum  of  mass  and  energy  is  conserved.  

So with that...do you think that the binding energy is the mass defect???

  

I let you know that the decrease in mass will be accompanied by a corresponding increase in energy and vice versa.

Mass does not magically appear and disappear at random.....

So with this, can u imagine it? 

Topic B for 7th October 2010

Hi!! Guest what? This is actually my first official duty. Well more specifically after I created this blog. Hmm I found that my teammates’ posts are very lengthy so I want to diversify my post (not to say that I am good enough). My writing/post may not be as good as Mr. Story Teller or too technical as others’. This time I would like to post in a simplified point form format. Even though today’s post is relatively general topic but I prefer to keep my facts straight.hah..mind u that, if my post cause u perplexity or complexity and tend to drive u crazy..plz..plz..plz..

-Please refer to another source for further details-

Nuclear Power in the World Today

• The first commercial nuclear power stations started operation in the 1950s.
• There are now some 436 commercial nuclear power reactors operating in 30 countries, with 372,000 MWe of total capacity.
• They provide about 15% of the world's electricity as continuous, reliable base-load power, and their efficiency is increasing.
• 56 countries operate a total of about 250 research reactors and a further 220 nuclear reactors power ships and submarines.

The Economics of Nuclear Power

• Nuclear power is cost competitive with other forms of electricity generation, except where there is direct access to low-cost fossil fuels.
• Fuel costs for nuclear plants are a minor proportion of total generating costs, though capital costs are greater than those for coal-fired plants and much greater than those for gas-fired plants.
• In assessing the economics of nuclear power, decommissioning and waste disposal costs are taken into account.

Radiation and Nuclear Energy

• Natural sources account for most of the radiation we all receive each year. Up to a quarter of that received is due to human activity and originates mainly from medical procedures. 
• The nuclear fuel cycle does not give rise to significant radiation exposure for members of the public.
• Radiation protection standards assume that any dose of radiation, no matter how small, involves a possible risk to human health. This deliberately conservative assumption is increasingly being questioned.

World Energy Needs and Nuclear Power

• The world will need greatly increased energy supply in the next 20 years, especially cleanly-generated electricity.
• Electricity demand is increasing much more rapidly than overall energy use and is likely to almost double from 2004 to 2030.
• Nuclear power provides about 15% of the world's electricity, almost 24% of electricity in OECD countries, and 34% in the EU. Its usage is increasing.
• Nuclear power is the most environmentally benign way of producing electricity on a large scale. Without it most of the world would have to rely almost entirely on fossil fuels for continuous, reliable supply of electricity.
• Renewable energy sources other than hydro have high generating costs but are helpful at the margin in providing clean power.

AGAIN....

-Please refer to another source for further details-

Control Rods-(Monday summary)

hye...hye...everyone.Today post is about Control Rods in reactor...so, let's read together.=)

What is control rods (CR)?

Control rods is a rod made of chemical elements capable to absorbing many neutron without fissioning themselves.They are used in nuclear reactor to control the rate of fission of Uranium and Plutonium.

Why control rods is important?

Control rods like a 'heart' in nuclear reactor.Because too few fission events can slow down and automatically stop the chain reaction.Too much fission can overheat the core and lead to a meltdown.That's why control rods is much important here.

Materials of control rods 

• Silver,Ag
• Indium,In
• Cadmium,Cd
• Boron,B
• Hafnium,Hf

How CR work?

Nuclear engineers and technicians precisely control the amount of fission taking place by inserting control rods (upper left) into the fuel assembly(red box). The rods are made of a substance that readily absorbs neutrons, like graphite or cadmium. When things get too hot, technicians lower a few control rods into the core. The rods sop up some of the ricocheting neutrons, and the fission process slows down. The reverse is also true: control rods are removed to rev up the fissioning.

When control rods are lifted from the fuel assembly, neutrons (from the natural decay of uranium) bounce around and bombard other uranium atoms, causing them to split. This process gives off more neutrons and causes more splitting. This is a chain reaction. The heat generated from all this fissioning is converted into steam, which turns a turbine, which turns a generator that produces electricity.

REMEMBER, If the reaction gets too hot, the control rods are re-inserted to absorb neutrons. With fewer neutrons around, there is less bombardment and fissioning. The core cools; energy output slows down. 

CR effectiveness

CR effectiveness is depends on the how many ratio of the flux at the location of the rod to the average flux in the reactor. Figure 1 show, when a reactor has one CR,the CR is must be place in center part of reactor core.The CR has a maximum effect when  if it is placed in the reactor where the flux is maximum. At point A,if additional rods are added to this simple reactor, the most effective location is where the flux is maximum.

Figure 1:Effect of control rod on radial flux distribution

The exact value of reactivity that each control rods depends upon the reactor design. The reactivity caused by control motion  is referred to as control rod worth.

Type of CR

• Integral CR worth ( 'S' shape)

Figure below show the result of a value of rate of change of control worth as a function of control rod position.

Figure 2: Integral CR Worth

Function of integral CR worth curve is to define the ρ change due CR movement between two position. The integral CR worth is the total reactivity worth of the rod at the particular degree of withdrawal and is usually defined to be the greatest when the rod is fully withdrawn.

• Differential CR Worth (Bell shape) 

For figure tell us it has very low values at top and bottom of the core and a maximum at the center of the core. The curve has bell shape because of CR worth related to n flux and n flux max.Also,n flux max is highest in center of the core.

Figure 3: Differential CR Worth

 

At the bottom of the core, where there are few neutrons, rod movement has little effects,so change in rod worth is very little.The effect become greater, when the rod approach the center on the core. Basically, from center to the top inverse of the rod per inch will applied here.

Example of Control Rods 

Figure 4: PWR fuel with control rod CLUSTER

              figure 4: BWR fuel with CROSS ROAD design

Basic knowledge about Xenon

On Monday classes, Mr.Shamsul touch a little about Xenon. So,now...I would like to write something here as our knowledge. Let's check it out!!!

Xenon?

From my research, Xenon is also called ' STRANGER'. It name originates from the Greek word ' XENON'. Xenon is colorless, orderless, highly unreactive gaseous ( found in minute quantities in the atmosphere).

Characteristics of Xenon

Element  :Xenon (Xe)

Atomic no  : 54

Atomic mass   : 131.29 amu

Melting point : -111.9° C (-161.25°K)

Boiling point  : -108.1°C ( -165.05°K)

Neutron in Xenon  : 77

Crystal Structure   : Cubic

Color of  Xenon    : Colorless

Periodic Table: Group 18 ( Noble gases)

Did you realize?

If you realize, Xenon is commonly used as photographic strobe light ( lens camera,alarm light, arc lamp and etc). 

Xenon-135
Xenon is occurring consist of nine stable isotopes. For Xenon-135 is produces as a result of nuclear fission and acts as a nuclear absorber in nuclear reactor.

How it produce?
Xe¹³⁵ is produced directly from fission and from the BETA decay of Tellurium-135, as shown below.
Xe-135 subsequently beta decays to Cesium-135 then to Barium-135. The half-lives are shown in BLUE below the line.

Te¹³⁵  ======>   I¹³⁵  ======>  Xe¹³⁵=======>  Cs¹³⁵  =======>   Ba¹³⁵ 

<0.5 min               6.7 hr         9.2 hr        2 x 10⁶ yr

How it destroy?
It has two ways to destroy:

1. By its own radioactivity decay ( half-life 9.169 hours)
2. By neutron absorption to Xe136

From the observation, it take time to produced and also take a long time to destroy...ermmmmm???What it means that?you think???
Opsss...I got to go. I hope this simple info will give all some knowledge...I will update more later...adiosss! :)

Chernobyl continuity...

Owh ya ya I did said before that I will post the physics behind Chernobyl incident right? Unfortunately my lecturer doesn't have time to explain so here's how... I’ve posts the event sequence including the large picture related to effects of reactivity feedbacks before right. Try pinning it or relating it to this post. Sequence is the same so should be easy game to play. This is an article from

http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/xenon.html

A major contribution to the sequence of events leading to the Chernobyl nuclear disaster was the failure to anticipate the effect of "xenon poisoning" on the rate of the nuclear fission reaction in the Chernobyl nuclear reactor.

Neutron absorption is the main activity which controls the rate of nuclear fission in a reactor - the ²³⁵U absorbs thermal neutrons in order to fission, and produces other neutrons in the process to trigger other fissions in the chain reaction. To control the chain reaction, neutron absorbers in the control rods limit the rate of reaction, and the moderator (graphite in the case of Chernobyl) slows down the fast neutrons to enable the reaction to be sustained. It is a delicate balancing act requiring detailed knowledge and careful control.

One of the extraordinary sequences in the operation of a fission reaction is that of the production of iodine-135 as a fission product and its subsequent decay into xenon-135. Iodine-135 is a rather common fission product, reportedly amounting to up to 6% of the fission products. It has a rather small probability for absorbing a neutron, so it is not in itself a significant factor in the reaction rate control. But it has a half-life of about 6.7 hours and decays into xenon-135 (half-life 9.2 hours). The xenon-135 has a very large cross-section for neutron absorption, about 3 million barns under reactor conditions! This compares to 400-600 barns for the uranium fission event.

In the normal operation of a nuclear reactor, the presence of the xenon-135 is dealt with in the balancing of the reaction rate. Iodine-135 is produced, decays into xenon-135 which absorbs neutrons and is thereby "burned away" in the established balance of the operating conditions. There is an equilibrium concentration of both iodine-135 and xenon-135. But when the power level was drastically lowered at the Chernobyl reactor, the xenon-135 concentration began to increase because the parent iodine-135 was near full-power equilibrium concentration to produce it and the neutron flux necessary to "burn it away" was not present. It would eventually peak and decrease, but with a 9.2 hour half-life, that decrease would come too late!

When the persons conducting the tests on the Chernobyl reactor tried to increase the power at some point in their tests, it would not respond. They apparently did not have the understanding that the failure to increase was due to the absorption of neutrons by the xenon, so they completely removed the control rods to force the increase. The increased power then burned away the xenon and also caused voids in the cooling water, both of which rapidly increased the reaction rate, driving it out of control.

The "xenon poisoning" of the reaction rate had been known for many years, having been dealt with in the original plutonium production reactors at Hanford, Washington. In fact, it was dealt with in the original Manhattan Project where it presented itself as a dilemma - the researchers expected a given configuration to maintain a chain reaction and it failed to do so. They found that they had to increase the fuel concentration to overcome the xenon poisoning. So the phenomenon had been dealt with from the earliest days of our experience with nuclear fission, and should have been known by anyone who was in control of a nuclear reactor.

See this is a very good article. I picked it as it suits my writing style. It is easy to understand for those who prefer story telling format like me. If anyone got offended as a result of me doing some copy paste, I do apologize. The reason is that I don’t have sufficient time and understandings plus I don’t want to rob and ruin a very beautiful article. Sharing is caring…

By the way, maybe I’ll write on control rods within this week if possible. Or maybe one of my colleagues will do it.