Layered Protection at Power Plants
The Editorial Team | Date:
Security at power plants visibly deters and detects. With various technologies on-site and guards constantly patrolling, power plants are heavily protected against unauthorized entry. A&S explores critical areas and the systems deployed.
Power plant security can be divided into several levels. Depending on the facility, critical exterior areas include vehicular entrances, perimeter fence lines, pump houses and switch yards, said Darryl Polowaniuk, Manager of Security and Fire Safety Solutions at Johnson Controls. Perimeters can be protected using microwave sensors, direct burial detection, fence line detection, video surveillance with thermal imaging and guard patrols.
Entrance areas are generally protected through checkpoints, serpentines or vehicle gates integrated with access control and video surveillance for verification, Polowaniuk said.
Internal are as critical to operations include the main and subsidiary control centers, IT data rooms, telecom rooms, stores and warehouses where critical spares may be located, and computer rooms controlling plant process control systems, said Dale Zahn, VP of Business Development at Intellibind Technologies. These areas are often protected by access control, video surveillance and intrusion alarms.
Most power plants were built well before IP development, which means that changes and upgrades require budgeting, Zahn said.
Analog systems are based on standardized and accepted measures. With emerging technologies, many IP-based systems have yet to reach their full potential, Polowaniuk said.
Advances in reliability, fault tolerance and redundant solutions are pushing old systems to evolve to IP, said Javier Prieto, Security Leader for Spain and Portugal, Honeywell Building Solutions. Some Spanish nuclear plants have already evolved to using IP-based systems.
Network technologies are used for remote surveillance and expansion. A power plant requiring more coverage around water areas may install cameras across a small body of water. Analog cameras would need extensive cabling to accomplish this. "The cost is much lower to install network cameras over long distances," said Aluisio Figueiredo, COO of Intelligent Security Systems.
Open platform software supports various types of encoders, so the video system is less vendor-specific. "Most systems today are hybrid, with analog cameras and digital transmission and storage," said Anantharam Varayur, Director of Webcom Information Technology. "Customers can purchase any camera to replace broken ones and still use the same encoder."
An impediment to IP is the prevalence of legacy equipment. "Building systems like lifts or escalators, and plant and manufacturing equipment, are still based on serial or analog interfaces," said Richard Lack, Sales and Marketing Director at ASL Safety and Security. For full integration, management platforms must support both IP and analog systems.
"It is not a question of why users won't move to IP, it's that they are not always presented with viable options," Lack said. "The systems in use are still working and were approved years ago."
Fiber optics and wireless are common at power plants. "Remote locations use more fiber backbone, whereas closed environments tend to use reserved wireless frequencies," Figueiredo said.
In most plants, two LANs run separately. Surveillance footage is generally transmitted to a LAN not connected to the campus-wide network, Varayur said.
From cameras to encoders, analog transmission is preferred because power plants use specially armored coaxial cables. "UTP or STP cables, connecting megapixel network cameras, do not have this special protection, and in such electrically-charged environment, these cables are subjected to more interference," Varayur said.
Perimeters are protected by up to three lines of defense. "Critical functionality includes the flexibility to be able to set the alarm locally, while allowing for central monitoring, simple identification of the origin of an alarm and reliable verification," said experts from Siemens Building Technologies in a prepared statement.
Typical perimeter defenses include sensor cables on meshed fences, microwave barriers between the fence and protected building, and video surveillance to confirm and verify, said Fabrizio Leonardi, Marketing Director of CIAS.
Electronic sensors on fences can comprise an electronic card with specialized components that detect movement or vibration, said Martin Kowen, Export Director, GM Advanced Fencing and Security Technologies. "Each sensor has an ID and actively communicates with the system processing card, to know the exact location of the intrusion attempt."
Industry-acceptable false alarm rates are usually less than five false alarms per kilometer in a month, Kowen said. False alarms can be lowered by sensors interpreting anomalies. "If there is wind on the protected site, then data readings from each sensor will all change proportionally. This unified change in data reading will not cause a false alarm to sound," Kowen said.
Products based on fuzzy logic analysis measure and compare typical stored signals with the size, shape and rate of change of new signals, Leonardi said. Events that generate an alarm are date- and time-stamped, stored in memory and can be analyzed in real time.
Buried cables are often used between fences for detection. "We encountered major issues because buried cable sensors are easily affected from the electrically-charged grounds characteristic of many plants," said Hagai Katz, Senior VP of Marketing at Magal S3.
For outdoor perimeter equipment, power plants require lightning protection. If lightning strikes near the system, capacitors can charge and take the load, Katz said. It is important that outdoor systems are linked to uninterruptable power supplies.
Post-mounted radars integrated with cameras for verification can detect and track people or vehicles moving into detection zones, said Jason Burger, Sales and Marketing Manager at Navtech Radar. The control room can display information on an aerial map with corresponding video images.
Radar paired with video surveillance can better protect perimeters via wide-area tracking, Katz said.
Access control systems oversee exits and gates, including vehicle entrances, pipes, tunnels, employee gates, maintenance points, control rooms and so on, Katz said. Each gate has a different protection — car entrances may have a physical gate with cameras, LPR and guards. Conveyer belts could be protected by thermal cameras to watch for intruders climbing onto the belt and entering the plant.
Access control systems can be active and run up to 100,000 badges a day, said Kevin Pearman, Account Manager, Integrated Security and Building Management Systems, Bytes Systems Integration. Proximity or smart cards allow staff to access to buildings, and biometric technologies are used at critical areas to protect against identity theft. At major access control points, physical barriers are used, including turnstiles and heavy doors, coupled with X-ray baggage checks and radiation scanners at nuclear plants.
Access control is probably the oldest installed equipment at power plants, making upgrades a challenge. "Security managers have no desire to replace old equipment with new IP-based systems, but they would like the benefits of being able to open the door remotely and mapping out its status on a map," Figueiredo said. Protocol analyzers, essentially sensors deployed on doors, are substitutes when SDKs are not available. They can be used to integrate systems running on serial or RS-232 communication.
Adding biometrics is easier than linking existing systems. "If you're dealing with old technology, you run the risk of looking for manufacturers who aren't even in business anymore," Figueiredo said. "Integrating sophisticated technology like fingerprint or facial recognition biometrics gives you a huge advantage: direct support from the manufacturer."
Video Verification and Monitoring
A large mix of mostly analog cameras is installed at power plants. Fixed, PTZ, day and night, infrared, thermal, and higher resolution cameras monitor perimeter and indoor areas.
Real-time surveillance is mandatory. As systems are used to verify events at perimeter and access points, video footage must be transmitted at 30 fps, Figueiredo said.
Users are replacing broken cameras with higher resolution ones. "520 TVL is a minimum, and we are seeing more requests for megapixel cameras," Figueiredo said. For the most part, however, security managers are still learning about the benefits of megapixel and HD cameras.
Storage is vital — footage needs to be kept at least a month. The emphasis is on backup and redundancy.
Evacuation and Safety
Apart from security, safety is a primary concern. Power plants must have reliable voice alarm and evacuation systems to notify employees about airborne contaminants and other critical events.
Nuclear facilities often use voice alarm systems with confidence tones — a series of tone-generated blips broadcasted every 15 seconds indicate that the building evacuation system is operational. "If staff don't hear that confidence tone, immediate evacuation is necessary," Lack said.
In Europe, new legislation allows manufacturers to use field-proven IP-based routing rather than analog. "Voice alarm systems can now sit on the same physical network as the other subsystems," Lack said.