Impact on new plants
It's one thing to limp along with existing nuclear plants if it's just a matter of cost, and lacking evidence that performance is uncompromised. But it's easy to envision the day when the NRC rejects or delays a combined construction and operating license (COL) application for a new unit because the proposed plant's control system does not conform to the agency's requirements.
For example, the NRC requires that you "design the system for all 'anticipated faults.' " To the commission, that means that you must determine what the anticipated faults for your digital system are, instead of simply assuming that they are similar to the ones of your analog system. Such an exercise could greatly prolong the effort and time required to support a COL application.
Key recommendations
First, treat the issue of digital I&C at nuclear plants with the urgency it deserves. The impact of I&C on the safety, reliability, and performance of the plant is far greater than its relatively small portion of the maintenance and capital upgrade budget would suggest. This "tail," truly, can "wag the dog." The worldwide nuclear industry—which is effectively "all for one, and one for all" when it comes to suffering from an accident at any plant—can ill afford the consequences of waiting for the smoking gun to create urgency.
Second, utilities have to become better at specifying digital I&C systems and managing the projects. In the same vein, realistic schedules and time frames are required. As the unfolding experience overseas shows, these projects may need time frames of 10 to 15 years, not two to three years. Sharper pencils are needed for the business cases to support these projects as well. Owner/operators should be encouraged to drill down with the budgetary process to illuminate the real problems.
Third, let's not assume we have to reinvent the wheel. It's a global market out there. Nuclear plant designers and operators in other countries are applying digital control systems within regulatory frameworks at least as strict as ours, and without major incident. Instead of participating in insular task forces, U.S. nuclear utilities need to partner with their counterparts that have successfully applied digital controls. Appropriate NRC officials should meet with their counterparts overseas. Something analogous to a "sister city" partnership program could be implemented, facilitated by the United States Energy Association (which has a program like this for other purposes), the DOE, or NEI.
Fourth, U.S. utilities need to give I&C staffs the latitude to expand their horizons. Few I&C engineers and managers have the budget or time to participate in outreach and industry-level education and training activities associated with new technologies and projects overseas. Operating staffs have been pared to the bone. Today, designers and engineers at the plants are tackling emergent work on a day-to-day crash basis, with little regard for next week, much less next year. This has to change. Operating companies can consider partnering with outside firms that have the people and expertise to manage the longer-term direction for I&C systems.
Finally, the regulatory framework must shift from a cookbook approach to "learn and interpret," at least for I&C systems. The existing framework may have been effective for what we might call the post–Three Mile Island phase of the industry, to ensure that the large fleet of existing plants met the highest standards for safety and reliability. It may be time to acknowledge that the regulatory framework used to ensure excellence in operations may not be appropriate for guaranteeing that the best plant designs are being implemented for the new fleet.
The I&C industry has come a long way from the 1970s and 1980s, but the U.S. nuclear industry and regulatory community have not. Almost all other industries—including aviation, fossil power, and petrochemical—benefit from digital-based control and safety systems. It's about time the nuclear industry got out of the ditch and on the road again.
—Tim Hurst is one of POWER's new contributing editors and president of Hurst Technologies Corp. (www.hcinc.com), a consulting engineering firm specializing in I&C systems for nuclear and fossil-fueled power stations. He can be reached at 979-849-5068 or timh@hursttech.com.
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