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The Next Fukushima

M1Abrams

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China admits nuclear emergency response ‘inadequate’ as safety concerns halt construction of two Guangdong reactors


PUBLISHED : Wednesday, 27 January, 2016, 6:56pm
UPDATED : Thursday, 28 January, 2016, 3:45pm

Stephen Chen
[email protected]

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Work on two new reactors at the joint Sino-French Taishan Nuclear Power Station in Guangdong province has been halted over safety fears. File photo: AFP

China admitted on Wednesday its nuclear emergency response mechanism is “inadequate” for coping with “new situations and challenges” arising from its nuclear power plants.

The central government also said it had halted construction of two new-generation nuclear reactors in Guangdong province, because of safety concerns, but vowed that they would not be abandoned.

It said it also plans to build floating nuclear power stations – facilities that are like a huge buoy, with a nuclear reactor built inside, which can be moved from one area of sea to another.

as it seeks to triple its nuclear power generation capacity in five years.

In its first white paper on nuclear emergency response, published on Wednesday, Beijing said the existing disaster response programme was “inadequate” to cope with “new situation and challenges”.

“Facing the new situation and new challenges of the nuclear sector, China’s nuclear emergency response [system] still has certain inadequacies in terms of technology, equipment, human resources, capacity and standards, the white paper said.

The paper has proposed a series of measures to boost nuclear safety and said China had learned lessons from previous disasters, especially the Fukushima nuclear disaster in Japan in March 2011, when a tsunami sparked the meltdown of three nuclear reactors and the release of radioactive materials into the air.

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An aerial view of Japan’s stricken Fukushima Dai-Ichi power plant reactor, including smoke rising from one reactor (left), following the meltdown of three of its reactors after a tsunami in March 2011. Photo: AFP

Concerns over nuclear safety in Hong Kong and Macau have caught particular attention of the central government. A section in the white paper was dedicated to the issue with promise to “answer public concerns in time” and “clear the doubts”.

Xu Dazhe, chairman of the China Atomic Energy Authority, told a press conference on Wednesday that the construction of the two European Pressurised Reactors in Taishan, in Guangdong, had been delayed owing to safety concerns.

French nuclear safety authorities reported last year that a possible manufacturing defect might lead to unexpected spreading of cracks on the reactor vessel which contained the nuclear chain reactions.

The Taishan plant had been delayed because “we treat nuclear safety as top priority,” Xu said. “If there is a problem, we must fully investigate it before continuing other works,” Xu said.

However, Xu ruled out the possibility that the Taishan plant would be abandoned.

China’s nuclear power generation capacity would reach 58 gigawatts by 2020, which meant that the country would have nearly tripled its current capacity of 20GW in less than half a decade, the paper said.

Xu said the nation currently had 30 nuclear reactors in operation, with a capacity of 28.3GW and another 24 reactors with capacity of 26.7GW were under construction.

Authorities were planning to build a “marine floating power station”, which would go through “careful and scientific feasibility review”, he said.

“China is devoted to building itself into maritime power so we will definitely make full use of ocean resources,” he said.

The release of the paper coincided with the meeting on Wednesday of US Secretary of State John Kerry with top Chinese leaders to discuss North Korea’s nuclear programme, ahead of an expected trip by President Xi Jinping to the US for a nuclear security summit in March.

China will also speed up the drafting of a nuclear safety law and atomic energy law, and plans to establish a new national nuclear emergency rescue team of about 300 members. The nation’s armed forces will be involved.

Professor Li Qiang, a nuclear safety researcher at the Chinese Academy of Sciences’ Institute of Modern Physics, in Lanzhou, said he was glad that the government had realised the shortcomings in its nuclear disaster response system.

“Generally speaking, our hardware and software is 10 to 20 years behind some developed countries in the West,” he said.

“The construction of nuclear power plants and the build-up of disaster response system must be carried out simultaneously. Ignoring the later may lead to serious consequences,” Li added.

China has launched some of the world’s most ambitious projects on nuclear power. Government research institutes have been given tight deadlines to develop next-generation nuclear technology such as fast neutron, molten salt and accelerator driven reactors.

State-owned nuclear companies are also trying to sell their technology and reactors to other countries, including Britain, while considering controversial projects such as building a floating nuclear power plant in the South China Sea to provide remote islands in disputed waters.



 

motormafia

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Ever since Fukujima the reactor designers and regulatory authorities must had realized that reactor designs and construction can not be left as they are and need to add effective emergency shutdown capabilities and facilities, no matter how costly.

It is proven that the single regular cooling system can not be left as the sole system to take care of the duty. When anything unexpected knocked out the cooling system's function, there MUST be something else to fall back to. Can not leave the reactors to just melt down like Fukujima.

Each reactor need to have environment independent and effectively automated system to pop out (extremely hot) fuel rods one by one, cool them down to safe temperature and in adequate isolation apart from one another, stored safely.

This needs spaces, and facilities, and therefore reactors can not be located so tightly packed together. it is too dangerous during emergencies, to have such a big concentration of eggs and baskets, altogether within a tight spot.

The existing layout of e.g. Fukujima is very efficient when there is no disaster, but a worst nightmare when everything flipped to the wrong side.

Reliable automated system must be capable of popping off uranium fuel rods one by one, rapidly cooled e.g. by liquid nitrogen, and shafted into a container made of Control Rod Material (boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning.) Then conveyed automatically into a safe storage facility provided by design of the nuke power plant, to hold all the fuel rods, adequately separated and isolated apart.

https://en.wikipedia.org/wiki/Control_rod

Speed and efficiency of such emergency shut down system must be adequate for entire plant facility and reliability must be regularly tested and verified periodically. The regulatory authority must be satisfied, that entire plant with each and every reactor can be put safely into an emergency shut down mode, with all the fuel rods separated apart and cooled down and in safe storage, even under condition of quake, flood, tsunami etc, the automated emergency shut down system must work.

Fukujima went into hopeless crap because all their fucking fuel rods were remained helplessly inside reactor to melt down. Reactor is such a disastrous concentration spot once cooling system is fucked up entirely. It is also hopeless to do recovery and clean up. The melted core inside, if you pumped any coolant inside you are spreading the dangerous contamination to a wider area. If you sealed it up, it is fucking nuclear time bomb. Each reactor is one time bomb and there are so many in that place, nuke engineers and experts don't know how to clean up that huge pile of crap.


They are slowly step by step now in Fukujima taking out the fuel rods that had not melted down. These are soaked in a deep pool. But the ones inside the melted core, is still no way:

http://inhabitat.com/tepcos-dangero...lear-fuel-assemblies-from-fukushima-imminent/
 
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motormafia

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http://nuclear-news.net/2015/07/15/...h-bottom-of-fukushima-reactor-documents-show/


Nuclear fuel core melted through bottom of Fukushima reactor – documents show


Fukushima-aerial-viewDocument shows nuclear fuel burned through bottom of containment vessel under Fukushima reactor — Official: Leakage we observed indicates melt-through by ‘shell attack’ — “This is a very big problem… fuel debris in the PCV is doing something bad” (VIDEO) http://enenews.com/official-documen...mail&utm_campaign=Feed:+ENENews+(Energy+News)
[Good diagrams]

Shunichi Suzuki, Tokyo Electric Power Co., 2014 IRID Symposium (emphasis added):

• Part 30 – “This is the current situation… This is Unit No. 1, this shows the the lower part of the PCV [primary containment vessel]… Based on the results of research so far… the ‘sand cushion drain’… water is leaking here, which means that this section above there is damaged — so that is highly possible. Therefore, this is a very big problem, because if this is damaged, then one possibility is that shell attackhas happened [see drawing by General Electric at bottom right]. So the debris in the PCV is doing something bad to this, so we have to take that into consideration for investigation.”

• Part 31 – “Unit 2… the water level [in the suppression chamber] and the water level in the torus room is about the same . What that means is that at the bottom [of the S/C], there could be a hole. Not only there, but also there is a pump room and there are other pipings here, so that needs needs to be considered as well when they conduct the investigation.”

• Part 42 – “Unit 1… there is little fuel remaining in the core… Fuel debris exists even outside the pedestal. Therefore we give priority to outside pedestal investigation. I talked about suppressionchamber earlier, shell attack has happened perhaps— I said that — shell attack in Unit 1 is something like this. Debris may exist around here so… there is some fuel that has penetrated outside the pedestal… If debris is outside the pedestal we can’t reach it, therefore we have to consider opening a side area – it’s very unique… Regarding Unit 2 and 3… in Unit 3 we presume that more fuel than we expected has fallen down to the PCV… we cannot deny the possibility that fuel has gone outside the pedestal.”

• Part 55 – “This is a MAAP example [computer code used for estimating fuel debris position]. Improvement points… the height is increasing, we had a single transfer path [for the molten fuel], but it is going to be multiple paths. And also debris, a uniform debris deposit was the assumption, now however asymmetrical distribution has to be considered. And alsodebris below the PCV bottom [see TEPCO drawing at middle right], the behavior has to be considered.”

• Part 95 – “The level of damage is high so it may not be able to stop water… and it may not be possible to fully cover the fuel debris. In such a case innovative approaches could be considered.”

See also: US gov’t analysis says Fukushima is more serious than ‘China Syndrome’ — Destroyed reactors suffered drywell shell melt-through, the worst type of containment failure

And: Image published by embassy in Japan shows Fukushima melted fuel deep underground

Watch Suzuki’s presentation here
 
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