Areva Resources Canada is involved in uranium exploration, mining and milling. At its McClean Lake mine and mill site in northern Saskatchewan, Canada, the company produces 10 million pounds of yellowcake annually. With plans in place to expand capacity to produce up to 24 million pounds each year, Areva had some very specific reasons to upgrade its Provox control system, which had been in place since the facility was built in the mid 1990s. It chose the Emerson Process Solutions DeltaV system, and is now interested in adding Emerson’s intrinsically safe (IS) CHARMs technology.
“The mine site is very remote,” said Brian Burkowsky, account manager with Spartan Controls, which provides engineering services to Areva. “The area has no daily FedEx or UPS shipments, so Areva wanted to ensure its technology was reliable.” Burkowsky was speaking at the 2012 Emerson Global Users Exchange in Anaheim.
Areva’s migration to DeltaV began in steps starting in 2005. The driving idea behind the migration was to implement DeltaV for new areas of the plant as it expanded, while maintaining existing Provox systems until full conversion. Data dumps from the Provox system into DeltaV were conducted to ensure existing tuning values were implemented in the new DeltaV system, so that migration would maintain like-for-like operation.
Overall, the migration project had five principal goals:
• One set of DeltaV controllers for the existing solvent extraction plant as well as a new one, which will be built in the 2013/2014 timeframe. “Having one set of controls for both plants reduced control system hardware costs by 10 percent,” said Chad Sewell, P.E., electrical engineer, Areva Resources Canada.
• Maintain or reduce control system footprint. “With CHARMs, we went from needing 10 termination panels to only needing 8 — a 20 percent reduction in space requirements,” noted Sewell.
• Increase spare I/O capacity. The Provox system had 16 I/O points, CHARMs has 24, which increases I/O capacity by 50 percent. “There are now seven I/O card slots available for future expansion,” Sewell said.
•减少停机时间与系统installat有关ion. Migration was done terminal by terminal; the back panels stayed in place with just the Provox terminal panels being removed as the DeltaV panels were installed. DeltaV Explorer was used to commission HART I/O using AutoSense to re-connect HART devices. For the 200 I/O points so far migrated, it took 50 percent less time to migrate than was expected. “We budgeted for the process to take 5 days and it only took 2 and a half days,” said Sewell.
• Maintain facility’s hazardous rating. This was enabled by the IS circuitry built into CHARMs.
Thus far, Areva has achieved a 24 percent costs savings in comparison to total funds approved for the project, according to Burkowsky. Future plans for the migration include using DeltaV CHARMs for field marshalling, upgrading PLCs to CHARMs, and using Ethernet for motor control.
