Valve Failure Leads to White Finding at Dresden Nuclear Power Unit

Valve Failure Leads to White Finding at Dresden Nuclear Power Unit

The U.S. Nuclear Regulatory Commission (NRC) issued a white finding of low to moderate safety significance to Unit 2 of the Dresden Nuclear Power Station in Illinois.
In February, one of four valves in the reactor vessel depressurization and overpressure protection safety system failed a required maintenance test. A subsequent review showed that the valve failed because of improper reassembly during the last required test and maintenance in 2013 and increased vibration of plant components resulting from an extended power uprate. The valve failure happened while the plant was shut down and there was no impact on the public’s health or safety.
The safety system controls pressure in the reactor in certain accident conditions. Earlier this year, Exelon (NYSE: EXC) replaced all four valves with a more robust design successfully used at other plants to prevent damage from increased vibration following an uprate project. The uprate project was completed in 2009, and it is known to increase vibration levels on certain plant components, including valves in the depressurization and overpressure protection system. NRC inspectors determined that workers failed to develop effective installation and maintenance procedures and guidance to prevent valve damage in light of the new operating conditions.
Subscribe to Nuclear Power International magazine.

Did You Like this Article? Get All the Energy Industry News Delivered to Your Inbox

Subscribe to an email newsletter today at no cost and receive the latest news and information.

 Subscribe Now


The Time is Right for Optimum Reliability: Capital-Intensive Industries and Asset Performance Management

Imagine a plant that is no longer at risk of a random shutdown. Imagine not worrying about losing...

Going Digital: The New Normal in Oil & Gas

In this whitepaper you will learn how Keystone Engineering, ONGC, and Saipem are using software t...

Maximizing Operational Excellence

In a recent survey conducted by PennEnergy Research, 70% of surveyed energy industry professional...

Leveraging the Power of Information in the Energy Industry

Information Governance is about more than compliance. It’s about using your information to drive ...