Details on Nuclear plant operating extensions

Extending the life of nuclear reactors in the the United States with research from Oak Ridge National Lab

Comprehensive risk analysis provided by Oak Ridge National Laboratory researchers plays a crucial role in keeping billions of dollars of electricity generation on line – without compromising safety. In the absence of license renewal, more than 40 percent of the nation’s 104 nuclear power plant licenses will expire by 2015. The replacement cost value of electricity generation capacity being submitted by industry in 2007-2008 for 20-year extensions is close to $20 billion, according to Richard Bass of ORNL’s Computational Sciences and Engineering Division. The major concern is pressurized thermal shock, caused by either a rapid temperature or pressure change in the reactor vessel. This combined with the fact reactor vessels become embrittled over time increases the potential for a pre-existing crack to propagate through the vessel wall, causing failure. Using advanced risk-assessment engineering technologies and high-performance computing resources, ORNL provides the technical basis for the Nuclear Regulatory Commission to set standards used in the license renewal process. This research is funded by the NRC.

ORNL is also developing stainless steels that are stronger but five times cheaper than alternatives.

A new type of stainless steel alloy developed at Oak Ridge National Laboratory could allow for significantly increased operating temperatures and corresponding increases in efficiency in future energy production systems. The new alloys offer superior oxidation resistance compared to conventional stainless steels, without significant increased cost or decreased creep resistance (sagging at high temperature). What sets this proprietary material apart from other stainless steels is its ability to form protective aluminum oxide scales instead of chromium oxide scales. The combination of creep and oxidation resistance offered by these alloys previously was available only with nickel-base alloys, which are about five times more costly than the new stainless steels. This material also has potential applications in high-temperature (up to 800 degrees Celsius) chemical and process industry applications.

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