August 7, 2002

Embedded Linux VPN Appliance

Miles Gillham writes: "Full article with pictures located at Case Study - Remote analysis of Steam Generator inspection data from the Pt Lepreau Nuclear Facility using Snap Gear's VPN through the Internet

SnapGear products trusted to support critical path remote data transfer and analysis

The first known successful use of a VPN (Virtual Private Network) to transmit an entire ECT (Eddy Current Test) inspection of Steam Generators during a regularly scheduled Nuclear Plant Outage using the Internet was recently completed using a Snap Gear appliance. Large file binary Steam Generator inspection data was transmitted from New Brunswick Power's Point Lepreau Nuclear Power Station in Canada to a specialized data analysis team located in the small town of Snoqualmie, WA USA.

The implementation of this new technology represents a landmark step in security, remote access, ease of use, and cost-effectiveness towards meeting the requirements of this routine yet critical process. Traditionally, transfer of ECT data for remote analysis would have been facilitated through the use of an expensive Point-to-Point (P-P) dedicated T1 connection set-up specifically for the duration of the inspection process (typically lasting from 2 to 6 weeks). However, with the use of Snap Gear's PRO+ VPN router, the connection was securely linked via the existing internet backbone at a fraction of the cost and unlike the P-P T1 solution remained available for continued use to support the inspection and analysis of the plant.s auxiliary systems or for less critical special analytics scheduled to be performed after re-start of the power plant.

The on-site inspection processes were performed by Babcock & Wilcox, Canada. The large file binary format inspection data produced from the Eddy Current, a non-destructive testing technique, was spooled via Snap Gear's VPN Firewall Appliance through the internet to Snoqualmie, Washington for specialized data analysis. After the data was evaluated by industry certified analysts at Verner & James, Inc. (, the results were then transmitted back to B&W Canada at the Point Lepreau Power Station site via the same secure VPN circuit.

"We are extremely pleased with the performance of the VPN and our decision to use it," said Mary Addario, the inspection Project Manager for Babcock & Wilcox, Canada. Mary was an early proponent of using the VPN to transmit inspection data as a solution to increase flexibility while saving inspection cost for her customers. As a result of the successful Pt. Lepreau experience Ms. Addario has seen her vision come true.

Doug Calender, co-founder of Verner & James, Inc. said "We knew there had to be a way to use the internet backbone as a medium to securely transfer Eddy Current data and save our customers money. Remote data analysis depends upon a high bandwidth, reliable, secure and seamless connection to the site facility. Snap Gear's hardware provided exactly what we needed."

Patrick Oliver, site Project Manager for Babcock & Wilcox wrote:

"I am pleased to announce that the first time attempt at remote data analysis using VPN (Virtual Private Networking) technology has been a total success. In the past, the standard procedure for transferring ECT data to a remote site was to use a "point to point" T-1 line. This requires purchasing dedicated bandwidth from one or many telecommunication companies to complete the link. This was an expensive configuration that also required a long lead-time to initiate."

"For the 2002 outage, Verner and James proposed that we use VPN to transfer the ECT data from Pt. Lepreau for primary and secondary analysis. The advantage to VPN over the T-1 is that typically, a dedicated T-1 link is not required. In fact, VPN can utilize the site's existing high bandwidth Internet connection. The VPN then uses the internet cloud for transferring its encrypted data, therefore saving the utility the expense of purchasing a T-1 that would, in this case, span the entire continent.

Originally, our plan was to utilize Pt. Lepreau.s internal network to access the Internet. Unfortunately, we discovered that our crew trailers were too far away from the Administration building to connect the site's network. Therefore, we were required to purchase a dedicated T-1 which connected us directly to the Internet. Verner and James utilized their existing internal network and Internet as they have ample bandwidth to support it. The purchase of the T-1 at Pt. Lepreau did add an extra expense that we weren't expecting but the cost overall was still a fraction of what a point-to-point T-1 would have cost.

Under the above-mentioned configuration, the VPN performed flawlessly. We only had one isolated incident when the data slowed to an unacceptable level. It was determined that the cause was a brief loss of service (the actual Internet connection) which caused the VPN Router's buffer to reach capacity. A simple reboot of the router which took a couple of seconds corrected the problem and everything was back to normal."

About the Pt Lepreau Reactor

The reactor at Pt Lepreau on the Bay of Fundy, New Brunswick, Canada is a 640-700MegaWatt facility that achieved initial criticality in July 1982 with commercial operation commencing in February 1983.

The reactor is a CANDU (CANadian Deuterium Uranium) model which is a unique design, the CANDU system uses deuterium oxide (heavy water) as moderator and natural uranium as fuel.

The core of the nuclear steam supply system of a CANDU 6 power plant is a large cylindrical vessel called the calandria. This vessel is filled with cool, low-pressure heavy water. The vessel houses 380 horizontal tubes, loaded with natural uranium fuel bundles.

With the uranium fuel surrounded by heavy water, chain reaction fission takes place, releasing energy in the form of heat. The heat is transferred to a second heavy water system pumped at high pressure through the tubes to steam generators. There its heat is transferred to ordinary water which boils to become the steam that drives the turbine generator.


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