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NRC Chairman says Westinghouse must address some issues with AP1000 reactor design

The US Nuclear Regulatory Commission (NRC) issued a statement saying that its efforts to confirm its review of Westinghouse’s amended AP1000 reactor (earlier post) design have resulted in the uncovering of additional technical issues.

NRC Chairman Gregory Jaczkow said that Westinghouse must resolve the issues before the NRC can consider finalizing NRC certification of the design. The agency will determine what impact this effort may have on the schedule for the AP1000 design amendment and related license application reviews after the staff examines the company’s response on these matters.

When the Commission approved issuance of the proposed certification rule earlier this year, the rule language noted the need for what, at the time, were additional calculations to confirm the staff’s technical analysis. That work has led to more questions regarding the AP1000’s shield building, as well as the peak accident pressures expected within containment.

The NRC said that it has made it clear to Westinghouse that it must prove to the agency’s satisfaction that the company has appropriately and completely documented the adequacy of the design. NRC staff will examine Westinghouse’s quality assurance and corrective actions programs as part of an inspection next week, and expects the company will submit additional information early next month.



The fact that Japan did not have cooling water and pumps on higher ground should bring some assumptions into question. Some designs are putting water on the roof so at least you have gravity feed for a bit if nothing else works.


Good idea SJC but reactors and associated buildings and equipment should be more resistant to Earth quakes and fires. Known Earth quake areas should be avoided. Japan (and the rest of the world) may have learned where not to build nuclear plants.

Stan Peterson

The Fukishima reactors handled the enormous earthquakes very well. Every one of the 51 reactors in Japan, shut down,"scrammed", as they should have done. The subsequent Wall of Water swept away some of the diesel electric emergency generators, at Fukishima.

The AP-1000 doesn't need these any longer, as the circulation has been redesigned to allow it to be done by normal thermal circulation, while the extra cooling feed water is placed in tanks above the reactors to flow into them by gravity, withut reliance on any power source.

This proves the foresight of the present generation of engineers and designers, and confirms that these new designs are what nuclear power plants should have been from the start.

So had the reactors at Fukishima been Gen III+ AP-1000 designs, they would have absorbed not only the Earthquake but the flooding by the Tsunami, without concern or damage.

The only concern that Fuskishima raised is the possible problems associated with storage of used reactor rods. The holding/cooling pools external to the reactors themselves, need a robustness that the reactor itself, now has achieved.

But it seems the Obama people are determined to sabotage nuclear energy by subversion and "permitoriums" also used to obstuct, delay, and prevent energy drilling, while maintaining their supposed interest in increasing energy supplies.


Actualy what we know now is the old big reactor design is OLD and we realy should go to modual tiny reactors that dont need cooling at all or to other modern designs that again dont ever need cooling. Such as pebblebed reactors and the like.

The good news is if what they are saying is true china will likely build the worlds first working fusion powerplant within 20 years...


I think we can to better, heavy water reactors and thorium can be much better at using uranium and even spent fuel rods, but there is always waste and danger.

The ocean wave did more to damage the reactors than the quake. Japan has 4 major sites on the ocean all with 6 reactors each that could have the same thing happen.

Most are old GE designs that were state of the art 40 years ago, but that was 40 years ago. Let's get smart about replacing those reactors with better designs. I am not a nuclear proponent, but realistically it is a source.


According to NYT, some of the factors that contribute to the Fukushima accident were the mechanical failures and design flaws in the emergency venting system which would relieve the pressure building inside the reactor:

"[o]ne reason the venting system at the plant ... did not work is that it relied on the same sources of electricity as the rest of the plant: backup generators that were in basements at the plant and vulnerable to tsunamis. But the earthquake may also have damaged the valves that are part of the venting system, preventing them from working even when operators tried to manually open them"

NYT: In Japan Reactor Failings, Danger Signs for the US


Non-Russian military reactors have safely run ships, even in typhoons, for hundreds of ship decades.

Perhaps I'm mistaken, but it seems like the three BIG power plant reactor accidents all had redundant cooling systems, but they were ALL wiped out/un-powered with reactor damage.

Can't one of those cooling systems pump cooling water from a SAFE, REMOTE location?

LOL, LA is watered by pumps and water hundreds of miles away.


When examining fault tolerance, you look for linkages. In this case the link with all the reactors on the beach was the ocean and the huge washed over ALL of them.

Nick Lyons

What I've learned since the Fukishima disaster:

1. Japan is one big earthquake zone. All its coastline is susceptible to tsunamis. Old technology, poorly maintained and poorly regulated nuclear power plants dotted around Japan and on her coasts is a formula for disaster, eventually.

2. Conventional nuclear power plants rely on redundant, complex cooling systems to keep the fuel safe. Murphy's law remains in full force, and these plants are an invitation to Murphy to show his stuff, by and by.

3. Back in the 1940s and 50s we chose to build enriched uranium power plants because they generated bomb-making material. Much safer thorium/molten salt type reactor designs were abandoned. Time to step back and rethink.


Thorium seems to be a much better way to go. There should be enough plutonium from recycling fuel rods to last a long time. You use it to make the U233 from thorium and no more long term waste.

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