OPG gives media look inside nuclear waste management
"It's important to have regular meetings with municipal officials, the public and press so that you have confidence in what we're doing here," said Keith Mombourquette, Vice-President of Nuclear Waste Operation. "We are trying to be as transparent as possible."
He pointed out that low-level and intermediate-level waste from the Bruce, Darlington and Pickering has been safely stored, on an interim basis, at the Bruce site for 40 years. "The DGR will finally be a permanent storage unit for this waste," he said. "We have high-caliber, highly-trained people working for us and this is a quality operation. We're proud of this facility and the staff who run it."
Marie Wilson, OPG Media Relations Manager, said the DGR is currently in the Environmental Assessment (EA) stage, with guidelines expected soon. "Studies are being done and boreholes are being drilled to come up with evidence that the Bruce site is, in fact, the best area for the project. An Environmental Impact Study should be submitted to the review panel by late 2011, and EA approval and a construction license by the following year."
Construction of the facility is expected to take five years, and, once an operating license is approved, the facility should be up and running by 2018.
OPG spokesman, Kevin Orr, took the media on a tour of the control room where low-level waste is incinerated or compacted before being stored in one of several buildings above and below ground. About 95 per cent of the waste is low-level, such as mop heads, paper towels and rags, while five per cent is intermediate-level, such as resin liners. Nuclear waste that can't be compacted or burned, such as valves, pumps or large bars, are stored as they are.
"The waste is burned at 1,000 degrees Celsius and reduced to ash in the incinerator and everything is monitored from the time it enters the site until it is stored," said Orr. "The cost to incinerate low-level waste is $4,000 per cubic metre."
Before entering the used fuel dry storage facility, members of the press went through an extensive series of monitors including an explosives checker, a metal detector and several radiation monitors. Only then, were they allowed a close look at the containers and building where used (spent) fuel, from Bruce A and Bruce B generating stations only, is stored. Pickering and Darlington maintain their own used fuel storage at their sites.
The containers themselves have one half-inch layer of steel on the inside, followed by 20 inches of concrete and another one-inch layer of steel on the outside. Each weighs 73 tonnes when full, holds 384 used fuel bundles and costs $80,000 to $100,000. "They are built to last 50 years, but are expected to last twice as long, which is the time it will take for a permanent storage facility to be determined by the federal government," said Orr.
By 2009, OPG will have stored 1,000 dry used fuel containers at the three nuclear reactor sites in Ontario. The first dry storage building at the Bruce was completed in 2002 and can hold 500 containers. The second building was completed last year. OPG accepts about 65 containers per year from Bruce B and the same from Bruce A, once all four units have been refurbished.
Richard Heystee, manager of repository engineering with OPG, holds up a core sample of the Cobourg formation
13/01/2009 04:23 PM
In his presentation, Richard Heystee, Manager of Repository Engineering for the DGR, said, "The conceptual design has been updated and preliminary engineering will be done through 2009 and 2010. Thanks to discoveries made by borehole drilling and through the study of core samples, the DGR is now to be located 680 metres below the surface - 20 metres further down than originally planned, he said, in the northeast corner of the Bruce site, across from the waste management facility. It will be built within a stable limestone formation."
"A south panel of emplacement rooms will be for the low-level waste, while the north panel is for intermediate-level waste," said Heystee. "The surface building will be the same height as the reactor and house a receiving area, office and two vertical concrete-lined shafts leading to the repository below." According to Heystee, the next step is to come up with a conceptual drawing and make any changes to the design as required.
Mark Jensen, manager of geoscience with OPG, discusses core samples including the Queenston Shale and Cobourg formation at the media day Wednesday
Mark Jensen, Manager of Geoscience for the DGR, explained that, "The repository is actually being built 60 metres deeper than planned because that puts it in the best possible location - in a Cobourg rock formation, which is estimated to be 450 million to 490 million years old and seismically extremely stable." The original depth had been determined from historic gas and oil exploration drilling statistics but, once drilling began, it was found that the Cobourg formation ran deeper than expected.
Geophysicist Jim McLay (L) and senior engineer Dylan Luhowy of Ontario Power Generation, pose with a core sample from the area where the deep geologic repository is to be built
He added that the excitement, from a geology standpoint, is being able to study core samples drawn from the boreholes. "This is the first time in a long time that such samples have been taken from that depth." Several geologists and even local students, have been studying the remarkably intact core samples.
"The samples show just how good and tight the rock formation really
is," he added. "Below 100 metres, we were able to extract the core
intact and it was of excellent quality. We also discovered high salinity
water that cannot be used for any purpose. Other other words, we found
what we expected and that's good news."