By Pascal Sabatier, regional marketing manager, Honeywell Field Solutions
With general concerns about global oil supply, along with growing awareness of the dangerous effects of carbon dioxide emissions, most national authorities have launched programs to extend the life of existing nuclear power plants. However, as technology changes, much of the installed equipment is becoming obsolete. Furthermore, the efforts needed to keep current equipment in working order increase every year, largely due to the rising cost of spare parts, the gradual disappearance of manufacturers’ expertise and the growing lack of compatible hardware.
In many industries, replacing the outdated control room with a modern distributed control system (DCS) would be the most effective way of updating and future-proofing a facility. However, due to the extremely high level of quality and security measures required in the nuclear industry, replacing the whole control room is not a feasible option as the costs associated with the development, installation and certification are prohibitive in most cases. In addition, the level of investment required to train all personnel on an entirely new platform would further increase the downtime needed for installation and tests, significantly impacting plant operations.
Instead, replacing individual instruments without drastically modifying the existing control room structure is often the most flexible solution. For example, in the field of data acquisition, the numerous paper chart recorders still used in the control rooms are on the front line. However, problems associated with obsolescence, along with the mounting cost of consumables add to the other known drawbacks of the recorders, including:
- The high cost of paper charts storage and the difficulty of finding and processing old data
- The reliance on mechanical factors for precise measurement and the correct interpretation of trends on paper charts
- The unreliable nature of paper charts, which is caused by a large number of moving parts that make them prone to failure
A paperless DIN recorder.
As a result, replacing paper recorders with updated technology is common practice in most energy production facilities today. Modern paperless recorders are mechanically and electrically compatible with the older instruments, which makes one-to-one replacements simple and straightforward. Paper charts can easily be replaced with highly visible LCD screens and the devices can be configured according to the needs of the operators. This can greatly improve visibility into operations and requires no additional retraining.
Overall, the foremost condition for a nuclear control room is a product’s ability to provide a level of security and reliability suited to the application where it is installed, something an off-the-shelf product can provide. And, these types of products also enable organizations to choose from several manufacturers, while also making for easy upgrades and transitions when technology changes and evolves.
Developing new “nuclear-specific” equipment raises two major issues. First, the business opportunities are small, preventing operators and manufacturers from efficiently covering the development costs through a high volume of installations. This, in turn, keeps the cost of the equipment high. Also, after just a few years, component obsolescence can raise further problems.
Commercial-grade components, in contrast, do not have these issues. In numerous aspects, the improvements in technology, manufacturing standards and industrial know-how have brought the equipment to a level roughly equivalent to that of “military grade” equipment of the 70s. Improvements include:
- Use of surface mount components (SMC) with better temperature ratings and resistance to shocks and vibrations
- Meeting European directives of low voltage and electromagnetic compatibility, which push manufacturers to improve the electrical characteristics of products
- Setup of quality insurance programs like ISO9000 or 10CFRpart50, which are now commonplace
- Use of micro-processor-based and solid-state memory technology that allows for the creation of machines without any moving parts, improving reliability.
Adhering to Safety
Standard methods should be used to make sure commercial-grade components offer the necessary level of safety. These methods include risk and performance analysis tests. The few nuclear certification bodies that carry out these tests have recently seen a modification in their methods. In addition to technical analyses and tests, they also take into consideration the track record of the manufacturer and its products. The relationship between the manufacturer and the certification body may have changed, but their independence from each other remains a necessary condition to the validity of the analysis.
A Honeywell electronic recorder.
Requirements for Results
Overall, nuclear power plant control rooms require technology—including paperless recorders—that are built around three priorities: data safety, ease of use and ease of commissioning. As such, technology should meet the following specifications when it comes to these priorities:
Data safety: Process data should be encrypted and stored in an electronic memory based on flash technology, which can then be transferred onto a computer. This allows for saving by duplication in several locations, without risking the loss of any information. This also enables easy searching and makes data readily available for different services or for providing to regulation authorities. And, by encrypting data, it cannot be accessed or modified.
Ease of use: The graphic interface of nuclear control room technology should be fully configurable to easily meet the needs of operators. Data verification must also be quick and easy to perform, and the technology should eliminate the need to unroll and roll paper chart.
Ease of commissioning: DIN-sized recorders can replace 100-mm paper chart recorders, making commissioning much simpler than previous technology. These recorders also can be fitted with the same connector as the paper recorders they replace, greatly reducing installation time.
In addition, many applications enable recorders to be connected together in a local ethernet network, which enables data collection and clock synchronization without manual intervention. This also enables easy real-time communications, as well as archiving, searching, analysis, printing and exporting data to other software tools.
After roughly 20 years of existence, electronic data recorders are at a point now where they can provide unprecedented reliability and assurance for the operators by offering precision, data analysis tools, easy-to-understand interfaces and silent operations, among other features, that are now widely accepted in the industry. This technology has reached its maturity and is now safe and reliable enough to be widely installed in nuclear applications.
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