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Workers Try to Make Nuke Plant Y2K-Proof
By Kathryn Herzog
February 17, 1999
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Of all the alarming scenarios related to possible computer failures in the year 2000, perhaps most critical to public health is the safety of America's 103 nuclear-power plants. The Nuclear Regulatory Commission says the Y2K computer bug poses little threat to safety systems at nuclear reactors. But some nuclear power opponents say the utilities back-up plans for Y2K are not good enough to ensure the public's safety

WHEN THE MONTICELLO NUCLEAR-POWER PLANT WAS BUILT IN THE 1960s, Y2K was still a distant concept. Most of the electronics used in the plant predate the modern computer chip, which might cause Y2K problems. Workers at the plant say they've checked and rechecked thousands of plant components to prepare for any Y2K problems and ensure safety. But ultimately, it may be the simplest technology within the plant that causes the biggest problems.

Russell Van Dell is the Manager of Computer and Information Systems at NSP's Monticello plant.

Van Dell: We're right now standing in one of the diesel-generator compartments of the plant. These are very reliable. These are the same ones that are used down on the railroads. They're General Motors' diesels, they're some of the best made. These are as about as good as you can get, there wouldn't be anything finer.
The Monticello plant has two enormous diesel generators on site. If the plant loses its power source, these diesel generators would kick on. A nuclear-power plant, always needs a constant source of off-site electricity to keep the reactor core and the radioactive waste cool. Without power, the diesel generators are the plant's emergency backup to prevent a nuclear meltdown.

NSP's Van Dell says the generators are constantly tested and checked for malfunctions
Van Dell: They'll be ready to go. If there is a problem either within our plant or outside of the plant, they'll be ready to go just like any other day of the year. They're ready to perform their function and keep the core safe.
Critics of nuclear power say the backup generators are not enough to ensure the public's safety. Michael Mariotte is Executive Director of the Nuclear Information Resource Service or NIRS. The Washington-based nuclear-watchdog group has filed emergency petitions with the Nuclear Regulatory Commission to bring in additional sources of backup power in case the generators fail. Mariotte says there 's some question about how reliable rarely-used backup systems will be in the event of an emergency.
Mariotte: The problem is these generators are often unreliable and they are often out of service. The Nuclear Regulatory Commission has stated that these diesel generators have a 95% reliability rating. Our own research has shown that's just not the case. In fact, along with our petition we submitted a nine-page document just listing the problems that have occurred in these generators over just the past two years.
Mariotte says utilities across the country have experienced problems getting the generators to start up properly. NSP's Van Dell says the generators are routinely tested and can start up in less than 10 seconds. Still Mariotte says an additional backup is necessary.
Mariotte: If we had regional blackouts, and I'm not saying it's a probability, it's a possibility - if you had regional electric grid failure for example in the upper Midwest or Great Lakes areas, you could have as many as 10, 12, maybe two-dozen reactors all of a sudden sitting there without power.
Mariotte says the odds of all generators working are slim. NIRS wants the Nuclear Regulatory Commission to insist that all utilities can prove their generators are operable, have a 60 day supply of diesel fuel and backup power source on site by December first. Otherwise, Mariotte says the nuclear plants should be shut down until utilities can prove their reactors are ready for Y2K. The Monticello plant currently has a seven-day fuel supply and Van Dell says there are no plans to bring in any backup power source.

When computer engineers at the Monticello plant began looking for possible Y2K problems, they started with a database of more than 42,000 items - including radiation monitoring, security systems and emergency shutdown systems.

Standing in the plants main computer center, NSP's Van Dell says workers have now narrowed their search to about 500 items and he says the nuclear-power plant is on track to deal with the Y2K issue.

But workers have found Y2K-sensitive components that are related to overall plant safety.

For example, Van Dell says systems that control the level of water in the reactor core could be Y2K-sensitive. But, like other systems in a nuclear plant, there are backups.

NSP is now planning for the "what ifs". What if after all their testing of reactor parts, something is still affected by Y2K? Emergency plans are a standard requirement at nuclear-power plants. But with Y2K, workers are creating backup plans for systems they've already checked and rechecked.

One example is radiation monitoring.

Not only does Y2K threaten the health of the reactor, but also the health of plant workers. At various points throughout the plant, radiation-monitoring stations check workers' exposure levels. NSP's Van Dell says the monitors have been examined and are expected to work come the year 2000. But some of plants newest technologies, may pose problems.
Van Dell: The concern with Y2K and these is that these were purchased here in recent years. They're not part of the original equipment at the plant. It's a much-improved technology over what they used to use but they're also computer-based so there's microchips in these things that control these things and perform this function.
Van Dell says the plant will perform Y2K drills this spring and fall, possibly involving the city of Monticello police and emergency-service workers. Van Dell says one drill may include area schools to see how quickly children could be evacuated.

The NRC wants nuclear reactors like Monticello to be Y2K-compliant by July first. NSP says its confident it will meet or beat that deadline.

Kathryn Herzog covers issues in central Minnesota for Minnesota Public Radio. You can reach her at