SENECA, S.C. — The digital revolution is finally reaching America's nuclear power plants.

Sometime in the next few weeks, technicians will finish installing digital controls for the operating and safety systems of a nuclear plant reactor in western South Carolina, a move being closely watched by other nuclear complexes.

In a nation where a digital blender can be bought for about $30 at Walmart, the Oconee Nuclear Station reactor will be the first of the 104 reactors in the United States not controlled with the same analog technology that brought the world cassette tapes and slide rules.

It has taken nuclear power plants so long to go digital because regulators wanted assurances the new control systems were as reliable as the old ones and could not be compromised by hackers.

“The systems in the plants right now, they are doing an excellent job. The plants are very safe — they've been doing their jobs for years,” said Joe Naser, technical executive with the Electric Power Research Institute.

The goal of going digital is to save money. Most systems in a nuclear power plant are monitors with four sensors. If two of them have out-of-whack readings, engineers often have to “trip” the plant, or shut it down, until the problem is resolved. If a nuclear plant sits idle for a day, it can cost a utility company more than $2 million. That isn't spare change, even for a company like North Carolina-based plant operator Duke Energy, which earned $1.3 billion in 2010.

Unlike a human engineer, who can only take in one measurement at a time from one instrument, the digital system takes in thousands of readings at any moment. The computer can instantly figure out if a sensor is broken and ignore it.

The nuclear plant digital systems will provide operators with much more data about plant operations and a level of precision impossible with an analog system, which often requires the movement of components to get things done.

The youngest nuclear plant in the U.S. went online with analog controls in 1996.