PaintSquare.com
      | Connect Follow us on Twitter Like us on Facebook
About | Subscribe | Advertise
  

 

Get Paint BidTracker's Bridge Painting Opportunities of 2015

Paint and Coatings Industry News

Main News Page


NRC Challenged on Plant Corrosion

Wednesday, December 7, 2011

More items for Program/Project Management

Comment | More

Repeated stress corrosion cracking of stainless-steel components at a Michigan nuclear plant has a congressman asking federal regulators why they continue to allow use of the metal in such applications.

A Nuclear Regulatory Commission investigation into a service water pump failure that recently shut down the Palisades Nuclear Plant has traced the problem to the same intergranular stress corrosion cracking (IGSCC) that caused the same pump to fail in 2009.

 Palisades Nuclear Plant near South Haven, MI

 NRC

The same service water pump failed twice for the same reason in two years at Palisades Nuclear Plant, near South Haven, MI. The plant’s license was renewed in 2007, through 2031.

In an Inspection Report  issued Nov. 29, the NRC classified the discovery as a so-called “White” finding, indicating an issue “with low-to-moderate increased safety significance.”

However, the NRC issued no violations, despite what one congressman says is a long history of such problems at multiple facilities.

‘Well-Known History’

“I am concerned that this failure is the latest in a string of similar incidents at Palisades and other nuclear power plants over the last two decades, and may be related to the continued use of types 410 and 416 martensitic stainless steel (410SS and 416SS), which are used in components of SW pumps at nuclear power plants,” Rep. Edward Markey (D-MA), senior member of the House Energy and Commerce Committee, wrote last week to NRC chairman Greg Jaczko.

“The pumps are critical to reactor safety, and I am concerned that despite a well-known history of problems related to the vulnerability of these metals to intergranular stress corrosion cracking (IGSCC), they continue to be used and continue to cause failures in U.S. nuclear power plants.”

Markey says the metals’ vulnerability to IGSCC has been documented by the NRC and in scientific and industry operating literature.

Embrittlement Problems

The NRC’s finding says that the plant operator, Entergy Nuclear Operations Inc., “failed to take into consideration significant operating experience from as early as 1993 and as late as 2010 that linked IGSCC susceptibility of 410 and 416 stainless steels to temper embrittlement.”

Clearly, then, Markey says, making the information available to plant operators has not been sufficient to ensure the safe use of these metals. So why not issue relevant requirements?

The lack of mandates is “particularly alarming” since a 2007 NRC Information Notice characterized the pump cracking problem as difficult to detect, even with testing, he says.

“Operating experience also shows that pump shaft failures and coupling failures can result in sudden total loss of flow before standard performance monitoring techniques alert plant staff to the impending failure,” the 2007 NRC Notice states, according to Markey.

Operator Report

Entergy reported that the pump was inoperable for a month before it failed.

The report notes that the 416SS metal was installed in a 2007 design specification change. 

“Personnel involved in the design change process did not have sufficient metallurgical knowledge,” the report says. “Palisades did not obtain an adequate technical review by personnel with expertise in metallurgy.”

The report says that the choice of 416SS did not account for the corrosive Lake Michigan environment.

Questions and Requests

Markey requested that NRC provide a number of documents by Jan. 6. That includes a list of all plants that use 410SS and 416SS components and a list of their uses.

Noting that NRC moved in 2005 to increase inspections at plants that used another metal (steel Alloy 600) susceptible to degradation, he asks: “Will you initiate a similar review for the 410SS and 416SS steels used in pump components? If not, why not?”

Finally, he asks what actions the NRC will take to address the integrity of the 410SS and 416SS pump components now in use.

“If no such actions are planned,” he adds, “why not?”

Concrete Problems

The steel corrosion issue arose just days after the NRC issued a system-wide warning on the risk of concrete cracking and degradation at its facilities.

In that case, the agency was responding to a problem at the control building of the Seabrook Station Nuclear Plant in New Hampshire.

The concrete problem was laid to Alkali-Silica Reaction-induced (ASR) degradation, which occurs when alkalis—usually from cement—react with certain types of silica in the aggregate, in the presence of moisture.

   

Tagged categories: Corrosion; Cracking; Nuclear Power Plants; Regulations; Stainless steel

Comment from Tom Schwerdt, (12/8/2011, 8:40 AM)

Sounds like the nuclear industry (or at least some specific plants) really needs some materials experts. Continuing to specify a grade of steel which is known to fail is not just risky, it is financially backward as well. Plant shutdowns to replace a pump every couple of years instead of finding the root cause and addressing it is just.... shortsighted.


Comment Join the Conversation:

Sign in to our community to add your comments.

SAFE Systems, Inc.
Portable Blast &
Recovery Equipment

Trailer or skid mounted blast and recovery equipment. Systems designed for maximum versatility, environmental compliance
and overall cost savings.
Call 1-800-634-7278


Termarust Technologies
Termarust (HR CSA) Chemically Stops
Active Corrosion

Arch truss treated with Termarust's (HR CSA) in 2003. This steel arch bridge is rust free on all surfaces including the crevice corroded joints and connections.


U.S. Zinc
Historic Reliability. Innovative Performance.

We offer custom grades and packaging of zinc dust, oxide, metal and fines, U.S. Zinc provides direct shipping to locations worldwide. U.S. Zinc – Helping the world work™


Blastox/The TDJ Group, Inc.
Blastox - One Step
Lead Abatement

Don't waste $$ on added labor steps with other methods. Don't mix, meter or apply at the job-site. Avoid strict hazardous waste rules.
Let your painters paint!


HoldTight Solutions Inc.
NO FLASH RUST -
NO CONTAMINANTS

Our HoldTight®102 salt remover & flash rush inhibitor prevents flash rust by removing surface contaminants.
Contact us for your nearest distributor. (800) 319.8802 sales@holdtight.com


Armorthane
Polyurethane and Polyurea Sprayed-On Protection

Buy POLYURETHANE or POLYUREA coatings and spray equipment for years of proven chemical resistance, water- and weather-proofing, and structural improvements.


BASF
New resins from BASF will have metals loving water:

Excellent corrosion resistance, low VOC, high gloss, thin films basf.us/industrialcoatings
polyorders@basf.com
800-231-7868


International Paint LLC

International Paint Engineered Coatings

Learn about our solutions for:
  • Structural Steel
  • Piping & Equipment
  • Storage Tanks
  • Pressure Vessels
  • Secondary Containment


    Elcometer, Inc.
    Durability & Design meet
    Performance & Reliability

    Elcometer 319 Dewpoint Meter
    View the technical data on the Elcometer Dewpoint meter.

  •  
     
     
    Technology Publishing

    The Technology Publishing Network

    The Journal of Protective Coatings & Linings (JPCL) PaintSquare
    Durability + Design Paint BidTracker

     
    EXPLORE:      JPCL   |   PaintSquare News   |   Interact   |   Buying Guides   |   Webinars   |   Resources   |   Classifieds
    REGISTER AND SUBSCRIBE:      Free PaintSquare Registration   |   Subscribe to JPCL   |   Subscribe to PaintSquare News
    MORE:      About PaintSquare.com   |   Privacy policy   |   Terms & conditions   |   Site Map   |   Search   |   Contact Us
     

    © Copyright 2000-2015, Technology Publishing / PaintSquare, All rights reserved
    2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951; Tel 1-412-431-8300; Fax 1-412-431-5428; E-mail webmaster@paintsquare.com