Former U.S. regulator questions small nuclear reactor technology

A former head of the United States' nuclear regulator is raising questions about the molten-salt technology that would be used in one model of proposed New Brunswick-made nuclear reactors.

The technology pitched by Saint John's Moltex Energy is key to its business case because, the company argues, it would reuse some of the nuclear waste from Point Lepreau and lower the long-term cost and radioactivity of storing the remainder.

But Allison Macfarlane, the former chairperson of the U.S. Nuclear Regulatory Commission and a specialist in the storage of nuclear waste, said no one has yet proven that it's possible or viable to reprocess nuclear waste and lower the cost and risks of storage.

"Nobody knows what the numbers are, and anybody who gives you numbers is selling you a bridge to nowhere because they don't know," said Macfarlane, now the director of the School of Public Policy and Global Affairs at the University of British Columbia.

"Nobody's really doing this right now. … Nobody has ever set up a molten salt reactor and used it to produce electricity."

Macfarlane said she couldn't comment specifically on Moltex, calling information about the company's technology "very vague."

But she said the general selling point for molten-salt technology is dubious.

"Nobody's been able to answer my questions yet on what all these wastes are and how much of them there are, and how heat-producing they are and what their compositions are," she said.

"My sense is that all of these reactor folks have not really paid a lot of attention to the back end of these fuel cycles," she said, referring to the long-term risks and costs of securely storing nuclear waste.


Moltex is one of two Saint John-based companies pitching small nuclear reactors as the next step for nuclear power in the province and as a non-carbon-dioxide emitting alternative to fossil fuel electricity generation.

Moltex North America CEO Rory O'Sullivan said the company's technology will allow it to affordably extract the most radioactive parts of the existing nuclear waste from the Point Lepreau Generating Station.

The waste is now stored in pellet form in silos near the plant and is inspected regularly.

The process would remove less than one per cent of the material to fuel the Moltex reactor and O'Sullivan said that would make the remainder less radioactive for a much shorter amount of time.

Existing plans for nuclear waste in Canada are to store it in an eventual permanent repository deep underground, where it would be secure for the hundreds of thousands of years it remained radioactive.

Reduced storage time and expense

O'Sullivan said extracting and removing the most radioactive parts would reduce the needed storage time to only hundreds of years, and therefore lower the long-term expense.

"The vast majority will have decayed within a couple of hundred years back down to regular natural levels," he said in an interview.

Brian Chisholm, CBC
Brian Chisholm, CBC

Estimates for storing what's called intermediate radioactive material are from a hundred to a thousandfold cheaper, he said.

"It's very different in cost, complexity, depth underground. … That's obviously a very big, very appealing factor."

There is no permanent repository for storing spent nuclear fuel deep underground. The Nuclear Waste Management Organization, a national agency, is looking at two sites in Ontario but there's been no decision on a location.

Shorter-term radioactivity complicates storage

Macfarlane said a shorter-term radioactivity life for waste would actually complicate its storage underground because it might lead to a facility that has to be funded and secured rather than sealed up and abandoned.

"That means that you believe that the institutions that exist to keep monitoring that ... will exist for hundreds of years, and I think that is a ridiculous assumption," she said.

"I'm looking at the United States, I'm seeing institutions crumbling in a matter of a few years. I have no faith that institutions can last that long and that there will be streams of money to maintain the safety and security of these facilities. That's why you will need a deep geologic repository for this material."

My response is: prove it. - Allison Macfarlane, nuclear waste expert

And she said that's assuming the technology will successfully extract all of the most radioactive material.

"They are assuming that they remove one hundred per cent of the difficult, radionuclides, the difficult isotopes, that complicate the waste," she said.

"My response is: prove it. Because if you leave five per cent, you have high-level waste that you're going to be dealing with. If you leave one per cent, you're going to have high-level waste that you're going to be dealing with. So sorry, that one doesn't fly with me."

Macfarlane, a geologist by training, raised doubts about molten-salt technology and waste issues in a 2018 paper she co-authored for the Bulletin of the Atomic Scientists. In the U.S., she questioned plans for a long-term nuclear waste repository at Yucca Mountain, Nev.

'Baffled' by environmental backlash

A New Brunswick group opposed to small modular reactors, or SMRs, the Coalition for Responsible Energy Development, has been pointing to her research as another reason to doubt their viability.

O'Sullivan said he is "personally very baffled and frustrated" by opposition to SMRs by anti-nuclear activists.

He said such activists have long complained about nuclear waste as a key concern "and we think we've finally got a solution that's cost effective to deal with it, and we're still getting this backlash. … We're environmentalists and we have this backlash."

ARC Nuclear, the other Saint John-based company working on SMRs, also plans to use some existing nuclear waste in its reactor design.

The company said in a statement Thursday that its technology "has successfully been demonstrated, therefore proven, at the engineering scale," but no one was available for an interview.

Nuclear power essential to reduced emissions

NB Power has predicted the creation of thousands of job and a $1 billion boost to the provincial economy if SMRs are built here. The utility did not respond to a request for comment on Moltex's plan for Point Lepreau's nuclear waste.

The previous Liberal government handed Moltex and ARC a total of $10 million to support their research and development.

The federal government said nuclear power is essential to Canada reducing its emissions but has not provided funding to the two Saint John companies.