A local resident recently called me to talk about the proposed Deep Geological Repository (DGR) for spent nuclear fuel here in South Bruce. It’s a favourite topic of mine, so I was happy to receive the call. This fellow asked me if I had seen a recent letter in the paper from Michelle Stein, and he wondered what I thought about it? I suspect lots of other people also read the answer, so I’d like to share my thoughts here.
Ms. Stein’s letter was published back in April this year, and it talks about the intended process of building the DGR, and how much water it will use. The process involves drilling shafts down some 600m – 800m through bedrock, then removing enough rock to build a whole network of hallways and storage rooms down there. It’s a lot of drilling, and a lot of rock has to come out, and they use water in the drilling process. Ms. Stein questions where they’re going to get all the water, and what the impact will be on the local aquifer, etc.
First off, I think this is exactly the sort of question residents should be thinking about, and although Ms. Stein and I don’t agree on everything, I think it’s important for local residents to have facts about this sort of thing. The NWMO scientists, in my opinion, have made a very convincing case that the many layers of engineered and natural barriers will permanently protect the spent fuel once it’s in the repository, but building the DGR is a different matter. This looks a lot like a mining operation, and they will be digging out a lot of rock, and bringing it a long way up to the surface. For comparison, the CN Tower is 553m high, and the DGR will likely be significantly deeper than that. Drilling that far down and then building a warehouse down there will take a lot of water each day, through at least part of the 10-year construction phase of the DGR.
The NWMO made a clarification on this issue, in the June 3 meeting of the South Bruce CLC, (Page 40 in the minutes if you want to dig for it). It turns out Ms. Stein’s numbers were off a bit, but she had the right idea. They said they now expect to use less than 300 cubic meters of water per day. That still doesn’t mean much to most of us, so I’ve done a bit of Google searching and some rough math, to compare it to something many of us can relate to.
It looks like the average dairy cow uses around 40 gallons of water per day. (Those in the industry likely have better numbers, but that one seems to be cited as an approximation.) 300 cubic meters is about 66,300 imperial gallons, which is about equivalent to the water use of 1658 cows. That’s about the equivalent water usage of 4 large dairy farms. For further context, a large tanker truck holds over 10,000 gallons, so it could take up to 7 trucks a day if they were going to haul all that water in from lake Huron.
Here in Bruce County, the handling of spent nuclear fuel is not new to us. We’ve been doing that safely and successfully for over 50 years. But deep mining operations are new to us, and we should learn as much as we can, before making a decision regarding the DGR. Let’s keep the dialogue going.