A new NASA-developed material the space agency calls a ``superplastic'' is getting a tough but work-a-day commercial test. The plastic, LaRC-SI, is being tried as a coating for metal and concrete components in two Virginia nuclear power plants. If it works there, it will be put to work in other generating facilities, both nuclear and fossil fuel, researchers expect.
LaRC-SI is being applied in test areas in service-water pipes in an effort to reduce the frequency of costly maintenance. Now, the pipes must be cleaned regularly to remove hydroids, small organisms that live in lake and river water and attach themselves to the inside surfaces of pipes.
``The hydroids affect the plant's thermal efficiency, slightly lowering the electrical output of the generators,'' said Robert S. Saun-ders, vice president of nuclear operations at Virginia Power, a Richmond-based utility with 1.9 million customers. ``Hydroids are not a safety issue,'' he added.
Saunders said dollar savings in the utility's operations and maintenance account could amount to ``hundreds of thousands a year and have a tremendous rippling effect through the company and industry.''
NASA describes LaRC-SI as an amorphous thermoplastic that can withstand elevated temperatures and harsh conditions that would degrade or destroy conventional plastics. It can be sprayed as a protective coating on materials such as complex circuitry.
It also can be combined with compounds such as graphite, ceramics and metals to create a hybrid material with characteristics of both, according to the National Aeronautics and Space Administration.
``If you mix graphite with it, it will feel like metal, not plastic,'' said Rob Bryant, the researcher who invented the material at NASA-Langley Research Center in Hampton, Va. ``If you combine it with a ceramic powder it will feel like ceramic.
``Or, you can leave it alone as a plastic. You can make gears out of it, use it in electronic circuitry or spray it for a protective coating. It's very versatile.''
Because LaRC-SI is self-binding, other materials can be incorporated into the resin to create parts with unique characteristics. Depending on the other material, those characteristics include increased hardness, lower coefficient of thermal expansion, decreased friction, and higher compressive strength and wear resistance, Bryant said at a news conference late in March.
LaRC-SI can be injection or compression molded. It does not become soluble at temperatures above its softening point - which means it can bond itself to substances such as pipe, ceramics or other plastics, Bryant said.
The $100,000 worth of material to be used in the nuclear plants is being produced by NASA at Hampton and sold to Virginia Power.
If the test project warrants, commercial quantities will be produced by an as-yet-unselected private company.
NASA said it will provide the technology. Virginia Polytechnic Institute and State University in Blacksburg will test the material to develop a final product and application process.
