January 15, 2007

Tow nuclear power I&C out of the "digital ditch"

Tim Hurst, Hurst Technologies Corp.

Last year—whether you attended the ISA/EPRI Power Industry Symposium in June, the American Nuclear Society (ANS) Utility Working Conference in August, the EPRI/Nuclear Energy Institute (NEI) Digital I&C and Control Room Licensing Issues Workshop in the spring, or the Fifth International Topical Meeting on Nuclear Plant Instrumentation, Controls, and Human-Machine Interface Technology embedded in the ANS Winter Annual Meeting—one thing was clear: The application of digital I&C technology at U.S. nuclear plants is not going well.

 

EPRI's Ray Torok calls the differences between modern digital and traditional analog controls the "digital delta." One thing Torok notes is a tendency of plant owner/operators to "recycle analog specs" when articulating requirements for new systems. In a surprisingly candid presentation at ANS in Albuquerque, Tricia Bolian of AREVA NP Inc. conceded that most modernization programs in the U.S. are on hold. Initial project scopes were too ambitious and performance across vendors and projects has been poor. AREVA NP, a joint venture of AREVA's Framatome subsidiary and Siemens AG, was involved in at least three of the high-profile digital instrumentation and controls (I&C) upgrades.

When you consider that the issue also potentially affects new reactors seeking licenses, Torok's "delta" starts to feel more like a "ditch." In "DOE NP2010 Nuclear Power Plant Construction Infrastructure Assessment," a report prepared by MPR Associates Inc. and issued in October 2005, the lead conclusion in the executive summary reads as follows: "A significant threat to the successful construction of GEN III+ units [the next generation of reactors now seeking license for new projects] is the design and approval of the digital plant control systems."

And yet, all around the world, digital I&C retrofits and new plant applications seem to be progressing with greater expediency:

• John Stevens of Doosan/HF Controls observed in his presentation at ANS in Albuquerque that by 2010, the Republic of Korea will have 8,000 MW of nuclear capacity operating with various forms of nonsafety and safety-related digital I&C systems. For the most part, Korean plants apply U.S. standards from beginning to the end of the project.
• In Finland, the Loviisa plant (Figure 1), with two 1970s-vintage pressurized water reactors (PWRs), is getting a complete digital makeover of its I&C systems and human/machine interface that will take 10 years to complete. The new Olkiluoto European pressurized water reactor (EPWR) now under construction (Figure 2) also will feature fully integrated digital I&C systems.
• The Paks station in Hungary, with four VVER Soviet-designed reactors, underwent a four-year digital safety I&C upgrade.
• Switzerland is implementing, over a 14- to 16-year period, a program at the Leipstadt plant that includes replacing process computers, nonsafety I&C, safety-related I&C, and reactor protection systems, redesigning the main control room, and installing a new simulator.
• In Japan, the advanced boiler water reactor (ABWR) plants built over the past 10 years use highly integrated digital I&C systems to improve overall plant productivity, efficiency, and safety. Digital I&C systems are used for both safety-related and nonsafety-related control and protection functions. The systems have operated over the past decade with what is regarded as a high degree of success.

 

 

 

 

Many experts at the aforementioned meetings concede that the U.S. industry has been "treading water" on digital I&C since the early 1990s, when the concepts began proliferating widely. Although important upgrade projects have been conducted, the lack of definitive success means little commercial progress can be claimed.

Not only is U.S. activity stalled, but the rest of the world is surging ahead, affecting the American nuclear power's industry's ability to compete. How long can operating staffs and their service providers maintain, replace, reverse-engineer, or otherwise make do with obsolescent equipment? What will it take for those involved in new plants to understand the gravity of this issue? A greater sense of urgency is needed to advance the industry beyond the conference sessions, task forces, and working groups of the last 15 years to developing real solutions and making tangible progress.
 

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