Every year, nuclear utilities and vendors submit to NEI new and innovative practices they’ve developed to achieve better operations. NEI and a few industry folks analyze the submissions and hand out awards for the best new practices. The awards recognize industry employees in 14 categories—four vendor awards, nine process awards for innovation to improve safety, efficiency and nuclear plant performance, and one award for vision and leadership. This year there are a number of excellent innovations highlighted below. The full list of awards and descriptions can be found here.
Real-Time Method to Prevent Fuel Rod Defects
Tennessee Valley Authority (TVA) employees at the Browns Ferry nuclear energy facility in Alabama have been honored with the B. Ralph Sylvia “Best of the Best” Award for developing a state-of-the-art method to prevent reactor fuel rod defects. Using real-time stress monitoring of the sealed tubes that hold the uranium fuel pellets, a new methodology called XEDOR has proven highly effective.
Five years ago, the industry established a goal to eliminate by the end of 2010 fuel rod defects that could release radionuclides from fuel pellets. Some damage is caused by the interaction between fuel pellets and the metal tube material called cladding. The phenomenon can result in additional costs to utilities, affect plant operation and subject personnel performing repairs to additional radiation exposure.
Working with AREVA, the winning TVA team implemented a new methodology that performs real-time, on-line stress calculations for every six-inch fuel rod segment in all parts of the reactor core. It is the first method that can calculate how close fuel rods are to cladding damage, thus ensuring fuel integrity performance. The user-friendly methodology is incorporated into the core monitoring system, and provides the plant operating staff with fuel condition information that can be easily understood and applied. This method has reduced fuel leaks, increased reactor productivity, and avoided millions of dollars in additional costs.
Tungsten Radiation Shielding
Entergy employees at Arkansas Nuclear One won the Materials and Services Process Award for creating tungsten radiation shielding that effectively protects both equipment and personnel. The innovation has been used in Japan in response to the accident at the Fukushima Daiichi power station.
The new material shields piping and surfaces effectively and economically, and also has been fabricated into a radiation-shielding vest that workers wear—a breakthrough application. Made primarily from tungsten with iron metal powder immersed in a silicone polymer, the material is flexible, heat-resistant, nontoxic and nonhazardous.
The tungsten vest is a major advancement. Traditionally, the industry has only thought to “shield the source” of radiation. Now “shielding the person” can be done in a lightweight and effective way to reduce exposure on an individual level and provide industrial safety value. Tungsten shielding is twice as effective at lowering exposure rates as lead and saves more than $300,000 per maintenance outage.
Employees at Exelon Nuclear’s Clinton power station in Illinois are recipients of the Vision & Leadership Award for their pioneering development of the Isotope Test Assembly project. By simultaneously generating power and creating a widely used medical isotope—cobalt-60—the Exelon Nuclear team is addressing an urgent international medical need.
Cobalt-60 is used in noninvasive cancer therapy, with more than 15 million treatments each year in 80 countries. Cobalt-60 also is used in medical instrument sterilization, food preservation, package decontamination and pharmaceutical purification. The United States imports 95 percent of the cobalt isotopes that it uses for such purposes. To maintain a steady supply of isotopes to satisfy demand for necessary nuclear medicine procedures, the Exelon Nuclear’s team is working to create cobalt-60 in a commercial reactor during normal power generation.
To produce the isotope, cobalt-59 “targets” are added to some fuel assemblies in the reactor. During reactor operations, cobalt-59 atoms absorb neutrons and are transformed into cobalt-60 isotopes. The isotope rods are removed and shipped to a processing facility after several operating cycles. Cobalt-60 then is available for medical and other health and safety applications. The first commercial supply of cobalt-60 from Clinton will be available in 2014. Be sure to check out the rest of the awards.
A short video explaining the radiation shielding is below. As well, below is another short video explaining Exelon's medical isotopes project.