Naomi Senehi: Is it correct that you are the former CEO of Chalk River Labs?
1:32 Bob Walker: Bob Walker was first the CEO of the parent Atomic Energy of Canada Limited (AECL), and subsequently, Canadian Nuclear Laboratories. The main site for Canadian Nuclear Laboratories is at Chalk River. Bob Walker, a born and raised Canadian, spent most of his professional career in Ontario. When the AECL was restructured in 2015, Bob Walker retired, but does continue some governance work with universities and private sector. He has also worked with university think tanks and to write in the space of small modular reactors (SMR’s). SMR’s can be game changers for Canada and the world, but will require the nuclear industry to change in fundamental ways.
4:24 Bob Walker: In the mid-1970’s, Bob Walker was studying radiation effects in materials as part of his engineering graduate studies at McMaster University in Ontario. He looked at the effects of neutron damage from fusion reactions on the first wall of a containment vessel for a fusion reactor, and gravitated to studying the effects of ionizing radiation on semiconducting materials. In the 70’s, a new method was created to build very small semiconductor devices using ion implantation. This implantation process damages the crystalline structure of the semiconductor and Walker focused on learning about that damage. After graduation, Bob Walker moved into the defense science world, working as a defense scientist in one of Canada’s maritime defense laboratories, where he eventually transitioned into management and executive roles.
7:00 Bob Walker: Bob Walker started his career created SONAR systems for Canada’s Navy and Air Force. In the 1990’s, Walker managed one of the nine defense labs and moved back into the corporate office in Ottawa for the defense research and development organization, eventually becoming the CEO. Walker also served as the Chief Scientist for the Department of National Defense and for the Canadian Forces. While preparing for retirement, Walker was approached about joining the Atomic Energy of Canada Limited (AECL) as the Senior Vice President.
8:04 Bob Walker: The Atomic Energy of Canada Limited (AECL) is a crown corporation in Canada, which is a public sector business that operates with a private sector business model in a public policy area. AECL was created after World War II in 1952 and is the home of the Canada reactor technology and operates a number of laboratories, the biggest being Chalk River. The government decided it was time to restructure the AECL and approached Bob Walker, who had a science background and knowledge of government machinery, to serve as an executive responsible for running the labs. Walker led the Chalk River Lab for five years.
10:20 Bob Walker: About a decade ago, the nuclear power industry in Canada was facing some headwinds. AECL, the big player in nuclear technology development, was in the business of selling Canada reactors around the world and had periods of time that were not commercially successful. At the same time, the Chalk River Labs, whose assets and liabilities were owned by the government and home to the National Research Universal Reactor (NRU) research reactor, was in an unscheduled shutdown for 15 months while repairs were made to the NRU containment vessel. This reactor was also a major producer of medical isotopes for the global market, bringing significant price increases in healthcare around the world. The government decided it was time to take half of AECL and sell the CANDU reactor division into the private sector, to SNC Lavalin. When the sale was completed in 2011, Walker became the CEO of the residual AECL, which was now predominately the nuclear laboratories. In 2013, the government decided to move the nuclear laboratories into a government-owned, contractor-operated (GOCO) model, similar to how U.S. labs are managed. In 2013, a GOCO was created for the operation of the laboratories and packaged into a company called Canadian Nuclear Laboratories (CNL). Canada’s nuclear industry is in a better place than a decade ago, with the restructuring of AECL, new investments by federal government in CNL, and refurbishment of the CANDU fleet underway.
16:48 Bob Walker: Ontario has CANDU reactors at three nuclear facilities, two of which are being refurbished. The four reactors at Darlington is owned by Ontario Power Generation (OPG) and the eight reactors at the Bruce Power site have or are going under refurbishment, with funding from both public and private sectors. Due to this work, Ontario is getting an extension of clean technology for another 30 years at a very competitive price.
18:51 Bob Walker: AECL’s role has always been in the design, development, and construct of the reactors, but is not focused on operation, however it does support the operators. In Canada, nuclear power currently provides 15% of the electricity supply, and in the province of Ontario, nuclear provides 60%. New Brunswick also has a CANDU reactor, which pulls approximately 30% of its electricity from nuclear power.
20:30 Bob Walker: Canada reactors, either CANDU reactors or reactors built based on the CANDU design, exist in Romania, Argentina, China, South Korea, India, and Pakistan. About 10% of the global fleet of nuclear power reactors are CANDU reactors that originated in the research and development completed at the Chalk River Labs.
21:22 Bob Walker: In the 1950’s, Canada decided to pursue civil nuclear power, but not nuclear weapons. As a consequence, Canada avoided the use of enrichment technologies, instead developing reactor designs that used CANDU, approximately 6%, of uranium. In order to use unenriched uranium, neutrons need to be slowed down, which is accomplished through the use of heavy water. Heavy water uses the deuterium ion of hydrogen instead of the regular hydrogen and has a higher cross-section for higher interaction. The CANDU reactor is a pressurized heavy water reactor and has a number of fuel channels in the calandria. Fuel bundles of CANDU are put inside the fuel channels, allowing the reactor can be fueled at power online. China is particularly interested in CANDU reactors because it can process multiple types of fuel, opening the possibility to utilize used fuel from their light water reactors.
26:35 Bob Walker: Canada, specifically Chalk River Labs, pioneered the methods for producing radioactive medical isotopes and distributing them globally. Technetium-99 is a decay product from molybdenum; moly-99 is a fission byproduct of the fission of uranium. The half life of these materials are very short, approximately six days for moly-99, requiring a carefully timed system. Supply is determined by the physics of the decay chain and there is essentially no storage. A number of reactors produce these isotopes, which are then sent to a purifying facility and shipped to hospitals, which had radiopharmacies where moly-99 decays. This larger research reactor ultimately became expensive to maintain, and It was found that the operating cost was not being recovered through the sale of isotopes around the world.
33:40 Bob Walker: By the time the National Research Universal Reactor (NRU) was being shut down, the capacity to produce moly-99 was about double the actual demand, providing a safe overhead for if any of the reactors were offline for repairs. Ontario Power Generation (OPG) and Bruce Power both stepped up to produce medical isotopes. OPG’s Darlington reactor is now producing moly-99. Bruce Power is producing another medical isotope, cobalt-60, that used to come out of NRU. It is used to sterilize medical equipment, used in approximately 80% of all sterilization.
36:42 Bob Walker: Since CANDU reactors are fueled online, fuel bundles can be put into reactors tailored to contain targets for producing medical isotopes. Nuclear is the heart of the health of many people around the world. Approximately one billion patients have been treated with isotopes coming out of the National Research Universal Reactor (NRU) over the years.
39:24 Bob Walker: Walker hears concerns about the safety, management, and transportation about nuclear waste. Radioactive medical isotopes are transported around the world every day, with minimal concerns about incidents or accidents.
40:34 Bob Walker: There is a technical and engineering solution for nuclear waste, but concerns tend to be more social or related to policy. In all countries with nuclear power, the ultimate solution for nuclear waste is to remove the radioactive waste from the biosphere and placing it in the geosphere. This allows materials to decay safely away from living things. The Nuclear Waste Management Organization (NWMO) was formed in the late 1990’s mandated to decide on a location for Canada’s deep geological repository for used fuel. The site must have the right geologic formation for the storage and there must be a willing host community. In Canada, fuel goes through the reactor once and is them moved into local storage on-site. Later, it will be transported to the repository. If electricity had not been produced with nuclear power in the past, it would have been produced with other methods that would have increased carbon in the atmosphere.
48:10 Bob Walker: Once can look as waste as a liability into the future, or as the end of a life cycle that has saved lives. There is a possibility that, as technology matures, the CANDU used fuel could be reprocessed. It is currently not economic to reuse that fuel. Some small modular reactor (SMR) designs are specifically targeted to use used CANDU fuel.
50:41 Bob Walker: After leaving AECL, Walker has engaged in writing and exploring the paradigm shifts as small modular reactors (SMR’s) take hold in the nuclear industry. Since the reactors are much smaller, they can be simpler, in terms of designs, and have lower unit costs. This has a number of implications in the accessibility of nuclear power to markets, especially smaller grids. The technology in the heart of the reactor embodies advanced technologies, often called Generation IV technologies, where are inherently safer, use less fuel, can be operated remotely, and have flexible loading scenarios. The modularity of the units allows factory production which could lead to shorter times and lower cost to construct. SMR’s introduce the potential for new markets, such as rural communities that are inaccessible to grids and currently use diesel generation. SMR’s could also provide an on-grid application, by replacing coal-fired or natural gas plants at a 1:1 ratio. These applications could normalize nuclear power by increasing the number of reactors around the world and bringing it closer to home for many people. There are approximately 400 operating nuclear reactors today. After SMR’s are deployed, there could be 10,000 nuclear reactors by 2050, bringing the fleet concept of nuclear reactors. This would also mean the development, construction, operation, and decommissioning of units may be happening all at once, contradicting the existing model for nuclear reactors.
1:01:50 Bob Walker: The industry needs to give communities voice as to how this shift to SMR’s should happen. New nuclear is about new technologies, but also about allowing nuclear to solve problems that matter to our communities, since energy problem is a problem along with climate change. There are a number of people who aren’t convinced nuclear power is the way to go. Analyzing the risks and benefits of nuclear energy bring an opportunity to make nuclear power a big part of the energy solution the world needs to have going forward. Canada has a unique combination of capability and markets the country offers.