Saturday, October 22, 2011

China shifts targets for new nuclear plants

The country is still the most aggressive builder of reactors on the planet

The China Nuclear Energy Association (CNEA) told the Bloomberg financial wire service this week that it will cut its targets for building new nuclear reactors by about 10%.  Li Yongjiang, VP of CENA, said in an interview in Hong Kong, where he is attending an energy conference, that capacity will target 60-70 GWe by the end of this decade. Previously, China has announced targets of 80 GWE or greater.

China halted approvals of new nuclear power plants following the Fukushima crisis in Japan last March.  The government has issued several statements about the safety reviews of both existing plants and proposed new builds.  Most recently, Zhao Chengkun, VCP of CNEA, said the reviews were completed in August.  However, the results of the reviews have not been made public.

While China has said it will resume approvals of new reactors in 2012, it may have resumed the process coincident with the completion of the safety reviews.  The difference is that new projects with generation II designs will not go forward.

Near term goals set for 2015

Zhao said that while the overall target is being scaled back, the near term accomplishments are expected to develop 40 GWe of nuclear capacity by 2015 instead of 2020.  He added that none of China's coastal reactor sites would be vulnerable to a tsunami or the type of earthquake that hit Fukushima.

China is moving some of its new sites inland which will require improvements to transportation infrastructure.  Coastal projects have the advantage of allowing large components like reactor pressure vessels to be delivery by barge.

The main areas of safety concern in China are with its second-generation designs.  Most likely, Chinese officials will not approve any new projects referencing them.

At the nuclear conference in Hong Kong, Takuya Hattori, president of the Japan Atomic Industrial Forum, said the root causes of the Fukushima disaster were bureaucratic complacency, insufficient accident protection, unclear division of responsibility in emergency management, lack of government leadership, and inconsistent release of information by TEPCO to the government and the public.

In a statement last June  Zhao noted that the Chinese government should further improve systems of environmental monitoring and emergency responses. It should also strengthen public education about nuclear knowledge and build the capability of public emergency responses for people who live around nuclear plants.

Profile of China's nuclear program

China has 14 nuclear reactors in operation with more than two dozen planned or under construction.  Six of them are so-called 'third-generation' plants with advanced safety features. All of these reactors are imports - four from Westinghouse and two from Areva.  China plans to build an additional 50 reactors most of which will be generation III designs adapted through licensing of technology from the current round of imports.

The World Nuclear Association notes in its profile of China's nuclear program that achieving self-sufficiency in design and construction of reactors is one of the nation's main goals.  China has also said it will begin a program to export a generation III design starting perhaps as early as 2013, but first it must ramp up domestic staffing for construction and for nuclear safety oversight.  Also, it has to get a handle on quality assurance on manufacturing of nuclear components.  In response, Chinese universities are ramping up their programs to include hands-on training at reactor project sites.
Prior coverage on this blog

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Notes on the new template

After some experimentation, I’ve updated my blog template from the original of January 2007.  This is a more modern and even a bit austere in design. I think it is easy on the eyes and certainly helps set off the content. 

It moves the buttons and ads to the right which means, since we read left to right, you start with content, and not with ads, on the left side of the page.

I experimented with a Wordpress blog since I work with one at ANS Nuclear CafĂ©.  Wordpress has a lot to offer, but industry literature says that if you move platforms, it can take some time for your readers to catch up.   

Blogger has been improving with a new interface and better templates so that’s why I stayed with it.

Hopefully, no one will be too startled on a Saturday.  Comments are welcome.

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Friday, October 21, 2011

Dominion and NRC set path to re-start North Anna

A safety evaluation review and decision are expected in November

epicenterThe NRC's review of the effects of the August 23 earthquake on Dominion's North Anna power station is coming to a logical and reasonable close. The agency says the staff is writing a safety evaluation review that could result in a re-start decision letter by mid-November.

At a meeting of the full commission on October 21, NRC staff presented the findings of an Advanced Inspection Team (AIT). That report was completed Oct 3.

The NRC wrote in its "FAQ" about the earthquake . . . "ground motion experienced by plant structures . . . may have exceeded design [but] does not appear to appreciably encroach on built-in seismic design margin of safety related structures and components."

The bottom line is that the plant responded well to the event with no apparent damage to safety significant systems nor to other systems and buildings generally.

NRC official Martin J. Virgilio told the Richmond Times Dispatch Oct 18, “The plant actually rode it [the earthquake] out pretty well.”

Not moving tons of paper

Dominion VP Eugene Grecheck told this blog in an exclusive interview immediately following the NRC’s Oct 21 meeting that "the utility is pleased we don't have to re-analyze the entire plant."

He added that the NRC commissioners asked good questions during the Oct 21 meeting focused on technical reports provided by staff.

NRC spokesman Scott Burnell confirmed to this blog Oct 21 that following a public meeting in Mineral, VA, on November 1 to review the agency's findings, that staff will write the safety evaluation review and prepare the decision letter. If all goes well, it seems reasonable to think North Anna could be back in the business of providing power to its customers by Thanksgiving.

seismograph2 The August 23 earthquake that shut down the nuclear reactors at Dominion's North Anna power station created questions throughout the nuclear industry about how the reactor would be re-started given the amount of ground acceleration it experienced from the event.

As it turns out, the seismic design basis for the plant assumes an event duration of 15-30 seconds when in fact the actual duration was less than five seconds.

See also Indiana UniversityEarthquake Measurement

The two nuclear reactors at North Anna Power Station in Mineral, Va., automatically shut down following a 5.8 magnitude earthquake in Central Virginia on Aug. 23, 2011, at 1:51 p.m. ET. The epicenter was approximately 11 miles west-southwest from the station.

The earthquake’s vibrations exceeded North Anna’s design analysis at some frequencies, but no significant damage has been seen. Analysis shows that the earthquake’s intensity and duration were not sufficient to cause significant damage at the station.

Reason the reactors shut down

Nuclear reactor simulator (ANL)So why did the reactor trip? Grecheck says that the reactors shut down because instruments at the plant detected a negative flux and a corresponding drop in power of greater than five percent. Vibration of the reactor core from the earthquake caused changes in the characteristics of the coolant and its moderation of the neutrons.

See also WNNReactor Core Simulation” [image right]

Assuming all goes well and the safety evaluation review and resulting decision by the NRC allow Dominion to re-start its reactors, what does the decision mean for the future of seismic information and the design basis for nuclear reactors in the U.S.?

For starters, the Electric Power Research Institute (EPRI) in cooperation with the U.S. Geologic Survey and the NRC are developing new models to assess earthquake effects on reactors especially those on the east coast. Grecheck points out that current models are mostly based on west coast seismic information. See also New York Times "After quake, Virginia nuclear plant takes stock"

"The east coast rock is different," Grecheck said, "It's tighter and the waves travel further from the center of a quake." See also CNN "Why quake rang like a bell"

earthquakeNRC spoksman Burnell says that a generic information document, GI-199 (NRC briefing slides) will incorporate the new EPRI models and be complete by the end of 2011.

The full technical document is out for public review. Grecheck said Dominion hasn't finished the calculations that are part of its technical assessment of the model yet so it is too early to comment on it.

The issue of how plants ride out seismic events is one of seven key issues for the NRC following its review of the Fukushima crisis. On October 20 the NRC staff provided a proposal to the Commission that selected seven recommendations as most appropriate for immediate action.

The recommendations cover issues including the loss of all A/C electrical power at a reactor (also called “station blackout”), reviews of seismic and flooding hazards, emergency equipment and plant staff training.

Speed over time

The most important point in Dominion's briefing of the NRC commissioners on Oct 21, Grecheck said, is that while measuring acceleration is important, duration must also be taken into account when assessing whether a seismic event exceeds a reactor's design basis.

Grecheck said he's not anticipating major changes in the instrumentation of plants to measure seismic effects.

"It would be helpful to get all the information in one place at one time more quickly," he said.

Power may be back on soon

Overall, Grecheck expressed a certain amount of relief that the end of the post earthquake review is in sight.

Dominion told the Richmond Times Dispatch Oct 21 it has spent about $21 million to ensure the North Anna nuclear power station is safe to operate again. The cost of replacement power has been in the range of $1-2 million/day.

North Anna generates 1,806 MW from its two units — enough electricity to power 450,000 homes. Unit 1 began commercial operation in June, 1978 and Unit 2 followed in December 1980.

Dominion submitted a Combined Operating License (COL) application to the Nuclear Regulatory Commission on Nov. 27, 2007. If approved, the COL will give the company permission to build and operate the new nuclear unit, called North Anna 3.

On the Web

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Thursday, October 20, 2011

UK nuclear safety report clears way for new build

Energy Secretary Chris Huhne delivers Mike Weightman’s report to Parliament

There is no reason to stop or slow down the develop of new nuclear power stations or change the selected sites for them says a report issued Oct 10 by the U.K. Office of Nuclear Regulation.

A 300-page final report prepared by safety expert Mike Weightman (right) reviewed the events that took place at Fukushima, Japan. 

It says that the U.K. is taking the right steps to address the design basis for new nuclear facilities including issues like earthquakes and floods. (video interview)

The report emphasized that there is no fundamental weakness in the U.K. nuclear reactor licensing program or in the safety assessment principles and processes that support it.

Read the full details exclusively at the ANS Nuclear Cafe online now.

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