Wednesday, 4 April 2012

Safety of Nuclear Power Plant

The main component of Nuclear Power Plant (NPP) is nuclear reactor.  Nuclear reactor is an engineering device, in which nuclear fuel and structural materials are arranged such that a self-sustained fission chain reaction can occur in a controlled manner.

In term of nuclear reactor safety, there are two categories consist of :
  1. Multiple Barriers
  2. Defense-In-Depth.

Multiple Barriers is used to prevent the radioactive materials to the atmosphere where this particular radioactive materials causes radiological hazard to the individual, social, and environmental.
radiological hazard is adverse heath effects of radiation.

Meanwhile, Defense-In-Depth is acting to prevent accidents and mitigate the consequences.  The approaches are Multiple Physical Barriers and Multiple Level Protection.

Multiple Physical Barriers consists of five components which are fuel pellet, fuel cladding, Reactor Containment Structure (RCS) Boundary, Containment, and Exclusion Area Boundary (EAB).

[Figure 1: Multiple Physical Barriers][1]


[Figure 2: Multiple Physical Barriers][1]

Multiple Level Protection consist of five levels where from level 1 till level 5.


[Table 1: Multiple Level Protection of Nuclear Reactor][1]


Reference:
  1. Monograph by Assoc. Prof. Dr. Nasri A. Hamid.  Reactor Safety. Universiti Tenaga Nasional (UNITEN).  Semester 3 2011/2012.

Online Survey

[Please click at this link: http://www.surveymonkey.com/s/3HGK2XW]


This is a survey conducted by a group of students from Universiti Tenaga Nasional (UNITEN), to gauge the level of public awareness regarding power generation in Malaysia. Your inputs are highly beneficial to our study and will be treated with respect and confidentiality. We thank you in advance for your support and collaboration.



Brought to you by NukeTech


Which one is Nuclear Reactor?

People today get confuse about the nuclear reactor structure.  
Most of them thought that the tallest building is the nuclear.  
In fact, the tallest building is the cooling tower while the nuclear reactor is located next to the cooling tower.

[Arrow shows the nuclear reactor building while the tallest building is cooling tower] [1]


Basically, cooling tower is used to condense the spent steam back to water in the closed system.
The water was taken from nearby lake or river.
The cooling process forming condensation cloud where people often misunderstood.

[Figure above indicates to us the exact structure of nuclear reactor and cooling tower in a Nuclear Power Plant (NPP)][1]


Reference:

  1. Monograph by Assoc. Prof. Dr. Nasri A. Hamid. Nuclear Power Plant Systems and Components.  Universiti Tenaga Nasional (UNITEN).  Semester 3 2011/2012.



Tuesday, 3 April 2012

IS NUCLEAR ENERGY SAFE?



An energy source heats water to make steam; steam turns a turbine; the turbine generates electricity. But a nuclear reactor differs from fossil fuel-based plants in that it doesn’t burn anything and doesn’t produce any carbon-dioxide emissions. Zero. However, it’s based on radioactive materials and it produces radioactive waste. That’s where the concerns lie. I think it’s fair to say that whenever the topic of nuclear energy comes up, the question of its safety is high on the list of discussion points.



It’s a complicated topic, but to give you some food for thought, I interviewed a person from either side of the issue. First, I spoke with Tom Kauffman, senior media relations manager for the Nuclear Energy Institute in Washington, D.C. Kauffman has been in the industry for more than two decades, held a senior reactor operator license and was at Three Mile Island when the accident occurred in 1979. Out of that conversation, I came up with a list of questions, which I emailed to Edwin Lyman.
Lyman is a senior staff scientist at the Union of Concerned Scientists in Washington, D.C. His research focuses on the prevention of nuclear proliferation and nuclear terrorism, and prior to working at the UCS, he was the president of the Nuclear Control Institute. Lyman emailed his answers.
Below are Kauffman’s and Lyman’s responses to some of the main safety concerns hovering over the future of nuclear energy. Neither one saw the other’s answers, as I did not want them to debate each other, but rather provide information about these issues from their point of view. Since I spoke with Kauffman first, I’ll put his answers first. Here are their responses to this controversial issue:
Oftentimes the topic of Chernobyl comes up when nuclear energy is mentioned. Could a Chernobyl-type accident happen in the United States at a nuclear power plant?
Kauffman: No. A Chernobyl-type accident can’t happen in the United States. It’s physically impossible. The reactor was a completely different design. All of the U.S. nuclear plants are self-limiting. They can’t run out of control and explode. The Chernobyl reactor wasn’t self-limiting. That design is banned in the United States and in most other nations. People who bring it up are using it as a scare tactic. My Subaru is as likely to blow up like Chernobyl as one of our nuclear reactors.
Lyman: The short answer is yes. An accident resulting in a large radiological release to the environment comparable to or worse than that of Chernobyl could definitely occur at a U.S. nuclear power plant. While the particular accident mechanism resulting in a catastrophic release of radioactivity would be different for a U.S. light-water reactor than for a Chernobyl-type reactor, the outcome could be similar. The Nuclear Regulatory Commission has a policy that if a core-melt accident occurs (such as the one at Three Mile Island in 1979), then the probability that the event could result in a large radiological release should be less than 10 percent.
According to computer simulations, some U.S. reactors would comfortably meet this limit, while it is less clear for others. Some reactor-containment buildings could be ruptured by a hydrogen explosion, for example. In addition, when a plant is down for a refueling outage, the containment building is open to the environment, but the fuel remains hot and is still vulnerable to melting if cooling is interrupted. And finally, terrorists with the tactical skill to attack a nuclear plant would find it fairly easy to blow a hole in the containment building.

Reference :
1. IS NUCLEAR ENERGY SAFE?, Discovery News from world wide website : http://news.discovery.com/tech/is-nuclear-energy-safe.html

A Primer on Nuclear Safety: 1.3.3 Heat, Water, Steam, Mistakes


          Homer Simpson is wedded in the public mind to the issue of nuclear safety. We of course know that Homer is a reactor operator, and we know that Homer is going to make mistakes. Much of the Simpson’s humor comes from a wedding of the horrifying and the funny, and the jokes that link Homer’s professional lapses, with nuclear safety, are perfect examples of that link. We know that Homer is going to make mistakes, and that his job means that his mistakes can cause things to go horribly wrong. Some where in the back of their mind, most Simpson viewers, are probably aware that in the real world Homer would not get a job as a nuclear plant operator. Without that awareness watching Homer operate the reactor would simply be horrifying, not funny. Never-the-less in a back corner of their mind people wonder if there might be truth in the Homer Simpson image. The Canadian cartoon showing Homer advising Canadian Prime Minister Stephen Harper on nuclear safety plays off the Homer Simpson nuclear worker joke. In a way it this cartoon is the perfect expression of manipulative nuclear safety disinformation campaigns of anti-nuclear groups like Greenpeace. Nuclear safety occupied the minds of some of the 20th centuries finest scientist, and they fought for it with great integrity. Alvin Weinberg who was fired for his stand over nuclear safety,was surely the anthesis of Homer Simpson.

Homer Simpson was perhaps a little more representative of the Soviet nuclear workers. We have seen from the Soviet naval experience that reactor accidents can happen because of human error. How is it possible to manufacture a reactor which is built with such fundamental flaws, that cooling water fails to reach part of the core during the shake down cruise? The answer is quite simple. Give the reactor manufacturer an order that the reactor must be completed by a given date no matter what. Contingencies enter into the manufacturing process. A flue epidemic strikes the factors staff, and a third of the workers are home sick for two weeks. The remaining staff does the best that it can, but they have a deadline to keep, and the reactor goes out the door incomplete. A parts supplier fails to supply a vital part, that must be installed by a certain date if the reactor is to be completed on time. The part does not arrive, and the order is given to complete the reactor without it. A factory worker and his supervisor stay out late after work drinking. They both come to work the next morning very hung over. The worker fails to complete his assigned task for the day because of his hang over. The supervisor is too hung over to check on his subordinates work, and marks the tasks as complete.

There are ways for factory management to prevent such defective things from being manufactured. Just ask the Japanese. But not even the Japanese finish every project on time. The Japanese know that management staff and the workers must be well trained, and management and the factory staff must be motivated to do their job properly. The Japanese believe that there must also be a top to bottom commitment to quality control. For the Soviets, the words “quality control” were the punch line of a joke about the follies of the Capitalist system.

Of course, in order to build safe reactors, reactors must be designed safe. There is something basically wrong with the design of a reactor which goes critical if the pressure vessel lid is opened incorrectly. Even if there is a fundamental defect in the reactor design, once that defect is demonstrated through a criticality incident, and partial core melt down, it is inexcusable that the design flaw not be corrected. Yet we see the same design flaw leading to Soviet naval reactor accidents over and over. In contrast the United States Navy has never had in its entire history of naval reactor operations, a single incident of accidental criticality, followed by a partial core melt down.

During the 1960’s nuclear safety researchers had determined that major nuclear asccidents could occure due to unlikely sets of occurrences, none of which by itself could trigger a major accident, but which in an extremely unlikely combination of events could lead to disaster. Unlikely is not impossible, and it is even possible to calculate the odds of those unlikely events happening and a major reactor accident taking place. This lead to a new concept of nuclear safety, one which involved probabilistic risk assessment. Think of this in terms of a poker bet on drawing an inside straight.

The Three Mile Island accident was to prove the probabilistic theory of nuclear safety theory correct. The nuclear research community began to take a view of nuclear safety with focused on probabilities rather than certainties, and began to feel that safety approaches that were based on simple A causes B models of potential accidents failed to capture the whole picture. The Navy thought in terms of the A causes B theory, a theory that had worked for them. The Navy, in addition, thought that the safety concerns of the civilian scientist was damaging the future of a civilian nuclear industry. There is in fact little doubt that the AEC nuclear safety controversy of the 1960′s and early 1970′, little understood by the public, and largely ignored by historians,was to have profoundly adverse consequences for the future public reputation of nuclear safety.

Paradoxically one of the effects of Milton Shaw’s assault on the nuclear safety community, was the shutting down of research by nuclear safety researchers like George Parker. What was lost when Parker’s research was terminated was the knowledge that that even serious reactor accidents might not lead to major human disasters.

Reference : 

1. A Primer on Nuclear Safety: 1.3.3 Heat, Water, Steam, Mistakes. Energy From Thorium. from world      wide website : http://energyfromthorium.com/2008/06/24/a-primer-on-nuclear-safety-1-3-3-heat-water-steam-mistakes/

Monday, 2 April 2012

Nuclear and Beach

1. Beach located near to Kenting Nuclear Power Plant, Taiwan [1]


2. Beach at San Onofre Nuclear Generating Station, Pacific Coast of California, US [2][3] 


3. Nanwan beach is located beside of the Taipower' third nuclear power station, Taiwan [4]




4. Taiwan's fourth Nuclear Power Plant is near to Fulong Beach, Taiwan [5]

below are other pictures of NPP located near to the beach:

References:

  1. Taiwan: Country's Nuclear Power Plants Are High Risk (2011).  Global Voices, from World Wide web:  http://globalvoicesonline.org/2011/03/16/taiwan-countrys-nuclear-power-plants-are-high-risk/
  2. San Onofre nuclear plant reports more testing failures (2012).  Los Angeles Times, from World Wide web:  http://theocnow.com/author/los-angeles-times/page/5/
  3. "Human Error at San Onofre nuclear plant" (2008).  San Onofre Beach News & Recreation, from World Wide web:  http://www.sanonofrebeach.org/?p=1533
  4. Welcome to Taiwan's nuclear beach (2009).  Global Post, from World Wide web:  http://www.globalpost.com/dispatch/china-and-its-neighbors/090727/welcome-taiwans-nuclear-beach
  5. The cost of nuclear power (2011).  David on Formosa, from World Wide web:  http://blog.taiwan-guide.org/2011/03/cost-nuclear-power/



"Learn from Fukushima nuke disaster", DPM of Malaysia



SEOUL: THE world must learn from the mistakes made in Fukushima.
Deputy Prime Minister Tan Sri Muhyiddin Yassin, in addressing more than 50 of the world's top leaders yesterday, said even though the Fukushima incident last year had raised questions about the viability of a nuclear power programme, Malaysia sees that time and the circumstances of greater global energy demands will lead more and more countries towards nuclear energy.

As such, he said, all nations must agree to the cardinal principles underlying the activities related to the peaceful uses of nuclear energy.

[Tan Sri Muhyiddin Yassin (third row) during group photography session]

Muhyiddin said all states must exercise full transparency in nuclear programmes and subject them to the full scope of the International Atomic Energy Agency (IAEA) safeguards and verification.

He also said all nations should adhere to the provisions of the Nuclear Non-Proliferation Treaty and gain the confidence and trust of the international community over the peaceful nature of their respective nuclear programmes.

He was speaking at the second plenary session of the Seoul Nuclear Security Summit 2012 (NSS), attended by 52 world leaders and the heads of five international organisations.

Speaking to Malaysian media later, Muhyiddin said these were the measures Malaysia was following, even though it had yet to decide on whether to move towards the use of nuclear energy.

"In Malaysia, we are transparent. We have given our assurances that we will study every aspect of nuclear energy before deciding. We have brought in international consultants and the IAEA and will adhere to whatever they say before we even decide on whether to go ahead."

Muhyiddin said he had stressed this during his intervention at the leaders' working lunch yesterday.
On its part, Malaysia reiterated the call made by Prime Minister Datuk Seri Najib Razak when he attended the first NSS in Washington, DC, in 2010.

"We reiterate our call... for countries to seriously consider the establishment of a UN convention on nuclear security that would, inter alia, legally mandate and strengthen the IAEA to promote and ensure nuclear security universally," Muhyiddin told the leaders in the plenary session.

On the next summit, two years from now in the Netherlands, he hoped more progress would be made towards the agreements arrived at as early as the Washington NSS, especially regarding the security of nuclear material.

Meanwhile, 53 leaders including Muhyiddin adopted the Seoul Communique of which the aspects included the fundamental responsibility of states to maintain security of nuclear materials through effective legislative and regulatory framework. (Source: New Straits Times)




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