Refueling in the time of COVID-19
The coronavirus has turned daily life upside down for most industries, and keeping nuclear power stations running, maintained and refueled has proved its own challenge for operators.
Refueling has been a particularly acute headache, with the typically around 12- to 18-month fueling cycle of many plants involving crews of over a thousand technicians from far and wide descending on a facility and spending several weeks working in cramped, overheated conditions during the plant’s outage.
“It’s a huge undertaking normally, but when you add COVID-19 it becomes that much more challenging,” says Ken Holt, spokesman for Dominion Energy which presided over three outages in the spring.
“We first identified workers that were essential to the success of the outage and to the operation of the other unit, because they are all two unit sites, so while one is down the other is still operating.”
Dominion shut down three plants in the spring to refuel and immediately put a wide range of restrictions in place including testing workers identified as essential, restricting control room access, moving all meetings to virtual calls, installing temperature-monitoring stations and creating work pods of five or six people so as to limit interaction amongst the hundreds of visiting staff.
“There’s mandatory mask requirements, we bought thousands of gallons of hand sanitizer and we probably, at one point, had the largest collection of cleaning wipes on the east coast,” says Holt.
American Electric Power’s Senior Vice President and Chief Nuclear Officer Joel Gebbie notes that the spring outage helped to lay the ground work for the current refueling of its Cook Plant Unit 1, though added that, while in the spring the country was in lock down, the economy had since opened up, making onsite testing and measures especially important.
With some 850 refueling outage contractors traveling to the site (reduced from a normal influx of 1,200) the company added to day-to-day measures - temperature testing and daily health questionnaires - and gave full COVID-19 tests to all of the newcomers with a 24-48-hour turnaround.
At the Cook Plant, the team concentrated on physical distancing as a means to keep workers safe, constructing two, fully ventilated, temporary buildings within the plant grounds to space out its contractors, moved out its permanent staff into disused buildings on the site and separated its construction trade workers – electricians, millwrights and ironworkers – from its radiation protection technicians.
The cafeteria meanwhile has been closed to make way for 29 new, six-foot-by-six-foot picnic tables.
“It’s hot and sweaty in the plant, and the workers really like to get out if they can and take their mask off, so we got these giant picnic tables,” says Gebbie.
Planned Outages in the United States in 2020
(Source: Nuclear Energy Institute)
Delays and innovations
Some scheduled plans have been delayed but others have helped usher in new methods.
While the Cook Plant has deferred a regulatory surveillance integrated leak rate test, due every 20 years, with Nuclear Regulatory Commission (NRC) permission, the virus has also helped fast-track other planned changes including inspection by drones beneath the condensers under the main turbines and laser mapping.
“We think in the future we can use the laser mapping and remote cameras to do that inspection, so we don’t have people up on that scaffold too close to each other. We’ve been looking at that with an eye on not just keeping people further apart, but it will also affect and improve our costs going forward,” Gebbie said.
In Finland, the Senior Vice President of the Okiluoto Power Plant Jaana Isotalo said that, after having spent years planning this year’s two outages, due in May and June, the virus forced them to rethink and ditch some of the non-essential work. Planned work that was expected to take 25 days was over in just under 15 days.
“Every year we do some modifications for the power plant, but this year some of them have been postponed for the next outage. By doing this, we were able to the scope a bit smaller which also meant we needed less personnel on the site we needed to bring less people from abroad,” says Isotalo.
The plant would normally count on between 1,000 and 1,500 incoming workers but this year’s refueling round had just 730, with only 100 people from outside the country, all of whom had to quarantine for 14 days and were tested twice; on arrival in Finland and a week after arrival.
Meticulous time keeping brought workers to the plant at five minute intervals in the morning to avoid queues, 24-hour testing and the inclusion of other special arrangements in work places and rest areas have all played their part in the plant’s plans.
In some ways, the nuclear sector has been well prepared for a pandemic of an airborne contagious virus, already counting on the generalized use of personal protective equipment (PPE) and carefully planned protocol aimed at avoiding potential contamination.
“When you work inside, foreign material is a major concern for us. We don’t want any movement that makes for more loose particles in the station and that’s always been the case. Nuclear workers are very much used to these methods and tools and taking precautions, and during the pandemic we used those tools that we already had in place,” says Isotalo.
As measures have gone into effect at the plants, the regulators themselves have been working overtime to instill proper work practices while keeping up the essential labour of monitoring and keeping strict regulatory practices in place.
At the U.S. NRC, within 24 hours of the order to set up teleworking, 98% of the staff had moved out of their offices and set up elsewhere, no small feat for as many as 3,700 people connecting to the network on any given day.
By the end of August, the NRC had issued a total of 217 reactor licensing actions related to COVID-19 while also implementing a process that licensees could utilize to submit certain exemptions or relief requests through an online submittal portal on the NRC public web site, NRC Commissioners said during a September meeting.
The new working conditions at the NRC improved efficiency, said Craig Erlanger of the Office of Nuclear Reactor Regulation.
Since beginning telework, the average age of completed operating reactor licensing actions decreased from 237 days to 129 days, the average number of actions completed per month had increased from 70 to 102, while the average number of new submittals had increased from 60 to 102, he said.
Some of the review efficiencies could be attributed to the development of COVID-19 specifics guidance for staff, the use of templates and the use of a tiger team approach to conduct reviews while lower absenteeism also played a factor in the NRC’s ability to complete actions in shorter timeframes, according to Erlanger.
New tools also helped focus on what was important and what could be left for another time.
“My favorite tool, and the most simple and effective that could be used by any member of the working group, or when a discussion reached the point of diminishing returns is ELMO. Which means, Enough, Let's Move On. And so, we would,” said Mark Lombard the Lead of COVID-19 Task Force at the NRC.
By Paul Day