Software helps manage change and compliance challenges in nuclear power facilities.
One reason complex systems are difficult to manage is that they naturally tend to evolve over time. For example, large infrastructure systems feature a mix of stable and rapidly changing elements. Changes may be triggered by wear and tear, the introduction of new technologies, new regulations, as a result of changing business conditions or a refined awareness of internal and external hazards. As modifications accumulate, systems based on almost identical designs will tend to diverge. Documentation tracking the changes that have been made becomes critical to operation efficiency, competitive advantage and personnel and equipment safety.
Configuration Management
The key to managing change in a complex environment is configuration management (CM). CM provides a method for effectively tracking and managing changes and ensuring conformance. Common sense best practices are at the heart of CM methods:
Changes to a configuration must be executed in a highly disciplined manner, with formal steps for developing and approving any changes to the system.
Proposed changes to a configuration must state what problem is being addressed, what resources will be needed, what outcome is desired and what will be impacted by the change.
An accurate, timely record of the system configuration must be kept and made available to all parties with a stake in planning, approving or executing a change.
No changes are allowed that could compromise the system’s ability to meet the needs that it was designed to address.
The Configuration Equilibrium
Complex facilities begin with documentation. Initiated with a contract, guided by requirements and specified by engineering drawings, a complex facility relies on solid documentation from its inception. Conformance to established requirements reduces schedule and cost risks and provides a foundation for safety through the life cycle of the facility. Once the facility is operational, changes immediately begin, and any divergence from the as-designed and as-built configurations requires careful tracking and maintenance in the documentation that reflects the physical facility to safely and efficiently operate.
Managing and documenting change is a natural outcome of successful configuration management. Information about the configuration must describe the current state of the facility and be detailed enough to support decision processes. Decisions made based on accurate information reduce business risk throughout the life cycle of the facility.
The Nuclear Power Industry Adopts CM
Nuclear facilities in North America feature a mix of new and old elements. The bulk of U.S. facilities were built between 1970 and 1990, well before CM became a popular discipline, and before CM certified software applications were available to aid in the management of complex configurations.
The U.S. nuclear industry faced many of the challenges that CM was designed to resolve. When operators began to take ownership of their new facilities, they found that these new installations came with less than thorough documentation. In addition, it quickly became apparent that the as-built configurations did not always match the as-designed—which in the nuclear industry was the critical design that was approved by the Nuclear Regulatory Commission (NRC).
Eventually, the U.S. Department of Energy would comment that “contractors at some of these plants had a less than stellar performance record regarding quality.1” Operators found themselves struggling to run these facilities safely and effectively and meet the expectations of regulators and the public.2
Figure 1. Configuration management method
Establishing a configuration equilibrium between the design requirements, the physical configuration and the supporting configuration (see Figure 1) became the key to meeting regulatory requirements and maintaining a safe working environment. This established CM as a key method at the heart of operational processes within nuclear facilities. Creating this equilibrium in retrospect was not an easy fix, but nuclear facilities have seen dramatic benefits through process improvements that have improved efficiency and safety.
Field Changes Reduced
CM’s technology has reduced a major source of cost overruns—the dreaded field change. A field change notice means something was missed. An unexpected problem has surfaced and must be resolved. In systems as complex as a nuclear facility, such surprises are never welcome. Field changes generate expensive delays and tie up personnel and resources while modification plans are developed, evaluated and approved. Even field changes identified during routine shutdowns are time consuming and expensive. If they are identified at other times and require an unplanned shutdown, the effects are exponentially more disruptive and challenging.
The CM method helps eliminate the information gaps and oversights that result in unwelcome field changes. It helps ensure the availability of accurate documentation underwriting requirements, physical equipment and even personnel training and certification. All these elements required to maintain a facility’s physical and operational configuration.
Now, CM-certified software applications are available that analyze this information. The software generates thorough change impact analysis reports to support decision making, regulatory compliance and safety.
At one U.S. nuclear facility, introducing a CM software solution resulted in major improvements in its engineering processes. The task was not trivial, but the results provided a quick and obvious return on investment. By identifying discrepancies and potential problems in advance and planning for them in the facility’s maintenance program, field change notices dropped from 34 to seven in one year.
Steam Generators and Their Systems
Replacing a plant’s steam generator is among the most complex and costly modifications undertaken at most nuclear facilities. Generators represent millions of dollars of investment. Replacing an old unit may impact pumps, seals, piping, valves, cooling units, instrumentation and monitoring systems throughout the plant. In addition, the shutdown required for the replacement process costs the plant millions of dollars per day. The planning process is intense and lengthy.
A replacement project such as this is also fraught with safety hazards due not only to the physical size of the equipment but obviously to the safety implications involved in any nuclear activity. One way to mitigate these safety risks is to ensure that the modification conforms to the engineering specifications required by the design basis as well as the physical configurations of the existing equipment with which it must inter-operate. Using a CM solution to ensure that the new equipment is correctly designed reduces risks during the installation process and subsequent operation, dramatically reducing the amount of field modifications and rework needed.
Proper CM can also increase the return on asset investment. In the nuclear industry’s first decades, inadequate access to accurate information resulted in excess system wear. Nearly 20 percent of steam generators had to be replaced earlier than expected.3 A CM solution can help track maintenance requirements and proposed and actual modifications. It can also help ensure that the changes conform to the design basis of the larger system, reducing safety risks as well as penalties due to regulatory non-compliance.
Setting a Record
In 2005, the Ameren Callaway nuclear plant implemented a CM-certified software solution to support the replacement of four steam generators. The project involved a huge number of manufacturing and construction records, including 14 modification packages; 1,552 calculations; 26 specifications; and 2,884 drawings from multiple sources, including Framatome and the steam generator team (SGT). The software solution structured, indexed and transferred all these records seamlessly and was cited as a reason the generators were replaced in under 64 days.
Performance Improvement
Nuclear performance improvement encompasses a number of safety related processes including corrective action, behavior-based safety and operating experience. U.S. nuclear facilities have used the CM method to recognize system and procedural defects, documentation gaps and other conditions adverse to quality (CAQs). By ensuring accurate, accessible information, CM can also contribute to the effective processes that are needed to resolve CAQs promptly and safely by identifying performance trends and human factors that affect progress.
Regulators Provide the Proof
Constellation Energy piloted a complete performance improvement program based on a CM software solution at its R. E. Ginna plant. Since implementing this program, Ginna has undergone a full NRC 95002 inspection and, facilitated by the ease and visibility with which the CM solutions accesses accurate information, received a successful result of “No Significant Findings.”
The results of the NRC inspection are significant, because they indicate the strength of the safety culture that has been instilled throughout the Constellation Energy fleet. In an era of heightened regulatory diligence, it is an indication of process and procedural success if inspectors cannot find anything wrong.
If It Works for Nuclear…
The nuclear industry is possibly the most highly regulated industry in the world, and justly so. However, the business risk and safety mitigation benefits that CM offers can be applied at non-nuclear facilities as well. The CM method and technology can provide many benefits:
- They ensure that facility modifications are properly planned.
- CM method and technology support the implementation of efficient changes that meet the original objectives
- They establish a process to ensure that accurate documentation is available for oversight and as a basis for future planning
References:
- Introduction to Quality Assurance, Basics of Quality Assurance Dept. of Energy, p.11, Office of Environmental Management Office of Standards and Quality Assurance.
- A.I.1.Overall Requirements/Quality Standards and Records, from Notice of Issuance of Amendment to Regulations 10CFR50, “Licensing of Production and Utilization Facilities,” which adds an Appendix A, “General Design Criteria for Nuclear Power Plants.” Feb. 10, 1971, ML003674723.
- “Steam Generator Degradation and Its Impact on Continued Operation of Pressurized Water Reactors in the United States,” by Kenneth Chuck Wade Energy Information Administration/ Electric Power Monthly August, 1995.
Pumps & Systems, April 2012