Starting Out in Nuclear (0:52)
(0:52-15:46) Robert explains how he first became interested in nuclear while studying mechanical engineering and his early career.
What did you study in school?
(0:52) Robert Mallozzi is the Regional Technology Director of Retubing, Maintenance, and Inspection at SNC-Lavalin. During college he studied mechanical engineering at McMaster University in Ontario, Canada. He also has his master’s degree in mechanical engineering.
Why did you get your master’s degree?
(1:09) During undergrad, Robert worked on nuclear research in the labs. When he was approached by a professor to continue his research with a master’s degree he thought it seemed like the right move for him. He even out to tour a real reactor as a student. The pool-bed type of reactor is still being used at McMaster University.
Walk me through your career.
(3:29) Robert started his career working on steam generators and stress analysis. For the next decade of his career Robert worked in inspections and performed maintenance and repairs on reactors. During that time he traveled to all of the CANDU sites and lead the teams performing inspections and repairs. A lot of the issues he dealt with were the replacement of components that weren’t meant to be replaced.
What kind of training did you have to go through?
(10:34) First, Robert went through training on the reactors themselves and learned about the components and systems. He also went through extensive safety training for zoning and hazards.
Inspecting and Retubing CANDU Reactors (16:58)
(16:58-20:59) Robert explains his background as a CANDU reactor inspector.
How frequently do you conduct inspections?
(16:58) Depending on the component and reactor, inspections take place every three or so years. Sometimes regulatory requirements need more frequent inspections. Some components will be inspected every year, depending on the life of the reactor, history, and the regulatory requirements.
Do you inspect reactors more as they get older?
(17:00) Typically, yes. The older the reactor gets and the closer it gets to the end of its life means it needs to be monitored more frequently. CANDU reactors have a 25 year first life. Then they go through the process of refurbishment or retubing. This can generally extend the reactor’s life about another 25 years. However, this 25 plus 25 operating life was not the original intent for CANDU reactors.
(21:00-47:13) Robert describes the process and timeline of refurbishment projects.
Why was refurbishment not part of the original CANDU design?
(21:00) Robert wasn’t around during the CANDU design process, but he thinks that the technology for refurbishment is so innovative that it just didn’t exist back when CANDU reactors were first created. For example, refurbishment includes a lot of robotics. There has also been technology invented to reduce the volume of the old components so smaller volumes of radioactive components have to be put into long term storage.
After your decade working in inspections, what did you do next?
(23:54) Next, Robert landed in New Brunswick working on the refurbishment of the CANDU reactor there. He then took a position looking after all of the systems for retubing the reactors. Basically process engineering to remove and inspect the reactor components.
What does a retubing look like from start to finish?
(25:48) The first step is to install tool control system platforms all around the reactor, these hold up the programmable logic controllers. Sometimes Robert would install cranes or temporary doorways in the building to get the tools in and out. Then each platform would have an automated worktable installed, each of which would perform different functions. All of the systems are controlled by a human technician but from farther away from the reactor in the control room. They control the robotic systems located inside the reactors.
How many days does refurbishment take?
(36:20) It depends on the reactor, but several months, 18 to 24 according to Robert. And once the retubing team is finished with replacing the fuel channels and all of the components are back together, and the tooling system has been removed, that is when the reactor systems get recommissioned. That process can take anywhere between three and nine months.
If we build a lot of new nuclear reactors, they’ll likely all need to be refurbished around the same time in 25 years. Where will we get the energy from during that period of time?
(38:26) In Ontario, one unit was built at a time. And now, that’s the same way they’re being refurbished. For example, at Darlington they’re refurbishing each unit separately to avoid having to shut down all four at one time.
Future of Nuclear Refurbishment
(47:14-54:45) Robert gives his take on the future of nuclear.
It’s important to have a mixture of different types of engineers working on these projects, how do you see the future of nuclear changing?
(47:14) Robert has seen a lot of computer programmers coming to the nuclear field and he thinks there’s going to be an increased need for that skillset. But the world of automation and logic control programming is expanding.
What is the main purpose of retubing?
(48:43) Overtime, the pressure tubes in the reactor grow, sag, and elongate with irradiation. They were only designed to grow a certain amount before they no longer remain on the bearings of the fuel channel.
How is the growth measured?
(49:34) As part of inspection programs, measurements are taken by the refueling machines to measure length.
Now, in your career, are you still very hands on during these processes or do you play more of a managerial role?
(50:18) Robert does a bit of both, he leads the retubing and inspection staff, but he also works to continue developing and supporting systems in the field. He contributes to the design review process. He also goes down to the laboratory at least once a day to check in on things that are developing. Robert’s staff numbers about 215 and more than half are in the lab; the other half are in the field. He currently has about 30 projects ongoing in the lab. They could be large refurbishment projects or smaller inspection contracts. His team works on a lot of inspection tooling.
After decades in this field, do you support nuclear?
(53:20) From day one Robert supported the nuclear industry and wanted to be part of it ever since he went on to get his master’s degree. He wanted to understand the problems the nuclear industry was facing. Robert hopes the nuclear field grows and public understanding of the technology increases, especially how green it is.