More from UWC 2020: Round 2

Decommissioning projects—the same but different

The end goals for any nuclear power plant decommissioning are generally the same: Remove and store the spent nuclear fuel and high-level waste, dismantle the unwanted buildings and structures, and ship the low-level waste and other debris off-site for disposal. Each decontamination and decommissioning project, however, is unique and poses its own set of challenges and solutions.

The UWC Decommissioning-sponsored panel session “Status of Decommissioning Projects in Progress and Completed to Date,” organized by Gerry van Noordennen of EnergySolutions, provided a broad overview of nuclear power D&D projects both past and current. The session focused on major differences between a plant’s original decommissioning plan and the realities of how things turned out during actual project execution.

• Vermont Yankee: Billy Reid, program manager for NorthStar Nuclear Decommissioning, and Corey Daniels, NorthStar Vermont Yankee ISFSI manager, provided an update of the decommissioning of Entergy’s Vermont Yankee plant, which shut down in 2014. Daniels said that NorthStar has a target of completing major decommissioning of Vermont Yankee by 2026. “We are ahead of that with a bit of margin,” he said.
• Daniels also highlighted NorthStar’s Target Zero safety program, which aims for zero workplace accidents. Target Zero, he said, is more than a slogan for the company, adding that 450,000 person-hours have been worked so far in decommissioning Vermont Yankee without a loss-time accident occurring. “We go slow to go fast,” he said
• La Crosse Boiling Water Reactor: Space limitations at the LACBWR site along the Mississippi River in western Wisconsin proved challenging to its decommissioning, said Joseph Nowak, project director for LaCrosseSolutions, an EnergySolutions subsidiary. Challenges included the demolition of an exhaust stack that was more than 300 feet in height. Because the reactor shared space with an operational fossil fuel plant, the stack could not simply be knocked down. Instead, it had to be dismantled from the top down.
• Decommissioning work at LACBWR was completed last year, and LaCrosseSolutions is currently working with the Nuclear Regulatory Commission on addressing final site closure reports. Nowak said he expects that the site license will be turned back over to owner Dairyland Power Cooperative later this year.
• Fort Calhoun: Owned and operated by the Omaha Public Power District (OPPD), the Fort Calhoun station was shut down in October 2016. The single-unit pressurized water reactor was moved to the NRC’s DECON status two years later, and OPPD has the goal of receiving license termination approval in 2026, said Tim Uehling, senior director of FCS Decommissioning. Uehling noted that the campaign to move Fort Calhoun’s spent nuclear fuel to dry storage was completed in May of this year.
• While OPPD has contracted EnergySolutions to decommission Fort Calhoun, the district will control the project and make key decommissioning decisions, Uehling said. “We felt that maintaining OPPD control was the best way to honor our community,” he said, adding that controlling the project also benefits OPPD employees.
• Humboldt Bay: Similar to LACBWR, the decommissioning of the Humboldt Bay nuclear reactor in northern California was constrained by the site’s size, noted Kristin Zaitz, engineering manager for Pacific Gas and Electric Company. Zaitz also said that Humboldt Bay’s unique features, with a reactor vessel located below grade in an area with a high water table, required flexibility in implementing a decommissioning plan. “Expect surprises and be flexible,” she said. Remediation of Humboldt Bay-3, a 63-MWe boiling water reactor, was completed in July 2019.
• Zaitz also stressed the importance of planning for safety. “Safety is not something you get lucky in. It’s something you plan for and pay for,” she said.
• San Onofre: The last of the session presentations, on the San Onofre Nuclear Generating Station, was delivered by Lou Bosch, plant manager of Southern California Edison San Onofre. Bosch highlighted a recent milestone in the decommissioning of San Onofre—the transfer of the plant’s spent nuclear fuel from wet to dry storage, which was completed on August 7. With 73 spent fuel canisters moved to San Onofre’s dry storage pad (an additional 50 canisters were already in storage on a separate pad), it was the largest dry storage campaign completed in the United States, Bosch said.
• Bosch also noted that while decommissioning projects are, in essence, the same, there are many different models for managing the work. “It is extremely important to find the right model that fits your plant,” he advised.

Human factors playing a role in control room modernization

As plants modernize their control rooms and new plants are designed, human factors, conduct of operations, and task analysis become key factors in ensuring continued safe operations. Ken Thomas of Idaho National Laboratory organized a session in the UWC Technology and Innovation track to discuss current research and innovative projects.

The panel, entitled “Insights into DOE Research, Human Factor Engineering Strategy for Phased Main Control Room Modernization and Cutting Edge Technology,” featured Katya Le Blanc, a senior human factors scientist at INL; Cindy Rivera, a digital modifications engineer at Arizona Public Service; Ron Boring, a distinguished scientist and manager at INL; and Ryan Flamand, supervisor of plant operations for NuScale.

• Le Blanc and Rivera delivered a presentation together about hybrid control rooms and Rivera’s work on digital modifications for the Palo Verde station. Rivera has relied on data from INL to assist in decision-making on a hybrid control concept for Palo Verde’s liquid radiological waste system upgrade.
• While analog instrumentation can be replaced, like for like, with a digital replica, any upgrade project offers an opportunity to improve human factors and efficiency. “In the nuclear industry we are a little bit behind other industries in integrating technology into our control rooms, so we can see what kind of technologies exist and how they’re being used before we’re able to actually implement them,” Le Blanc said.
• Control room design is not just a matter of opinion, according to Le Blanc. “We want to demonstrate that it improves performance,” she said. “The most direct way is to measure system performance. On top of that we also use eye tracking, which gives us a sense of how operators look for information. We can balance operator preferences with objective evidence that something works better.”
• Boring spoke about applying new technologies in today’s plants. With digital human–machine interfaces, “It’s no longer this two-dimensional concept, meaning control board inputs and outputs,” he said. “We’re trying out some of these ideas with reactors that haven’t been licensed yet, and the question is, why can’t we bring some of this technology back to our legacy plants? Can we use technology to sustain this industry and help us become more cost-competitive?”
• Like Le Blanc and Rivera, Boring urged investments in advanced control room technology rather than opting for like-for-like upgrades, explaining that a lot of the “heavy lifting” is done in the initial stages of any upgrade project. “I’d argue that the return on investment might be greater for advanced control rooms than for simple upgrades,” Boring said.
• Though with NuScale now, Flamand has worked as a reactor operator and senior reactor operator at the single-unit Palisades plant. NuScale’s planned 12-module plant with one digital control room represents quite a departure. The company is preparing to operate 12 reactors with a team of six operators: three senior reactor operators and three reactor operators.
• NuScale’s digital interfaces were planned to “minimize cross-talk and chatter” by using digital displays to give all operators access to the same information, while clearly showing who has responsibility for a given unit, Flamand said. Supervisors can review procedures in progress or after completion from their own workstations, without hovering over an operator’s shoulder.
• “The NuScale design supports us in the digital space by keeping controls non-safety,” Flamand said. “Everything you see that is digital is non-safety-related.” The design relies on natural circulation and an ultimate heat sink—all 12 reactors are submerged in a large reactor pool."

NRC Transformation

The UWC session “NRC Transformation” featured speakers from the Nuclear Regulatory Commission who discussed change activities that include agency-wide efforts to address cross-cutting aspects of culture, innovation, technology, and staff development. The change activities also include office-level elements focused on reactor licensing, oversight, and rulemaking.

The NRC is undertaking transformation to gain efficiencies in processes so that more time can be devoted to matters of greatest importance to the agency’s mission. The agency looks to manage evolving workloads and respond adeptly to emerging technology trends in the nuclear energy sector, develop a workforce that has the appropriate skills and tools to meet the mission needs, and use new approaches to data analytics to inform decision-making.

The session was sponsored by the Regulatory Relations and the Risk Management tracks and moderated by Ken Lowery of Southern Nuclear.

• Dan Dorman, deputy executive director for operations, noted that for the past decade the NRC has been responding to changes in the nuclear marketplace and how those changes impact the industry that the agency regulates. “Over that period, the NRC has reduced in size by about a third because of the things that are happening in the industry,” he said.
• For the past several years, the NRC’s leadership has focused on the need to strategically position the agency to adapt to the fundamental changes that are under way or are anticipated in the nuclear sector, Dorman added, saying, “The NRC adopted a transformation vision several years ago to become a modern, risk-informed regulator, to be prepared to regulate an industry that is innovative and has new technologies.”
• How will the NRC know that it has become a modern, risk-informed regulator? Dorman said that it’s when the agency makes sound decisions while accepting well-managed risks in decision-making; when it uses technology to work smarter, including using data analytics to highlight areas for regulatory attention and improvement; when it innovates and makes timely decisions that take into account different viewpoints and fully explored options; and when it maintains an engaged and highly skilled workforce now and in the future.
• Mirela Gavrilas, deputy director for reactor safety programs and mission support, talked about a risk initiative team (or, Be RiskSMART) formed within the NRC about 10 months ago to develop a framework that the agency could use to formalize risk-informed decision-making. She noted, however, that Be RiskSMART “was basically riding on the shoulders of the people who preceded us,” and she presented a timeline chart that stretched back to the 1970s, which showed the risk-informed decision-making events in the nuclear industry, starting with the Reactor Safety Study (WASH-1400) published 46 years ago.
• Gavrilas explained what the acronym part of the Be RiskSMART name stood for: Spot (what can go right or wrong, what the consequences are, and how likely it is for something to happen), Manage (what you can), Act (on a decision), Realize (the result), and Teach (others what you learned). SMART encompasses the five key principles of integrated risk-informed decision-making, she said, adding that the initiative is being introduced at the various levels of the NRC, and ideally every staffer would consider using it in their work.
• Shaun Anderson is the cofounder of Embark Venture Studio, which is the NRC Office of Nuclear Reactor Regulation’s dedicated resource for promoting and implementing innovation projects to benefit the nuclear reactor safety program, as well as other NRC groups.
• Embark’s primary goal is to remove barriers to innovation and launch initiatives that improve the way the NRC works to make the safe use of nuclear technology possible. It encourages staff to make real change. “I think it all comes down to getting out of the comfort zone and doing things a little bit differently,” he said.
• Anderson said that Embark has four departments: The Garage, which is Embark’s process improvement area; Neurology, which is about understanding risk, overcoming fear of failure, challenging the status quo, and breaking down barriers; Nextgen Data, which is about “embracing data and data analytics by developing some of the tools to manage our business at the NRC,” he said; and #HASHtagChange, which is about improving the experience of internal and external stakeholders.
• Jonathan Greives, chief of Projects Branch 4 in the Division of Reactor Projects in the NRC’s Region I, noted that the Reactor Oversight Process (ROP) has been and always will be risk-informed. “Continuous improvement is a key aspect of any risk-informed process,” he said.
• The ROP continues during the COVID-19 environment, Greives stressed. The NRC’s resident inspectors at nuclear plants moved to telework status at the start of the pandemic but came on-site initially once every three days. As the pandemic progressed, the NRC developed programs that allowed the agency’s managers to make database decisions on when to increase on-site inspector presence or to resume on-site team inspection activities.
• “I highlight these activities because I think it truly demonstrates the agility of our staff,” Greives said. “A number of the previous activities [such as] technology adoption in our risk-informed inspection program enabled us to very quickly adjust our activities in light of the public health emergency. We’re truly demonstrative of our work when becoming a modern risk-informed regulator.”

Exelon/DOE/INL Transformational Project

Sponsored by the Executive/Leadership track, this session served as a follow-up to the opening plenary and an earlier session by detailing the Transformational Change Project implemented by Exelon in cooperation with Idaho National Laboratory.

The session was sponsored by the Executive/Leadership track and was moderated by Craig Primer of INL.

• John Connelly, engineering manager of the Exelon Centralized Design Organization, presented material about the safety system modernization project that Exelon is undertaking at the Limerick nuclear plant in Pottstown, Pa. He said the time is right for modernization because original construction project systems are reaching the end of their service lives. In addition, he said the industry is facing significant economic challenges and must apply advanced technologies to ensure long-term sustainability.
• Replacing physical components of a system with digital software presents a “significant cost-reduction opportunity,” Connolly said. Exelon analyzed four of its safety-related systems (reactor protection, redundant reactivity control, nuclear steam supply shutoff, and emergency core cooling) and cut the number of safety-significant distinct components from roughly 2,400 to 600. “That’s 1,800 safety-significant components that can no longer fail because they no longer exist,” he said.
• Tying his presentation into the main UWC theme, Connelly said, “It truly is go time. The industry initiatives that we’ve been working on for several years now are finally coming to a convergence point that is pivotal in our ability to modernize.”
• Eric Benner, director of the Division of Engineering at the Office of Nuclear Regulation for the Nuclear Regulatory Commission, presented information about the NRC’s new approaches for licensing a safety-related digital instrumentation and control (I&C) upgrade. The NRC vision for digital I&C is “a clear regulatory structure with reduced regulatory uncertainty that enables expanded safe use of digital I&C in commercial nuclear reactors while continuing to ensure safety and security,” Benner said, quoting from NRC Commission Paper SECY-19-0112.
• Benner pointed to the issuing of NRC digital I&C interim staff guidance (ISG) 06 revision 2 as a recent licensing-related accomplishment for the NRC. The revision’s major change was to challenge the NRC to issue the licensing action much earlier in the developmental process for the digital I&C system. He also touted NRC Branch Technical Position 7-19, which uses a risk-informed graded approach to provide technical guidance to the staff for how it reviews a license application.
• Craig Primer, who leads INL’s plant modernization pathway, concluded the session with information about the transformational benefits of digital I&C modernization. He presented five key takeaways to support it.
• The takeaways were: maintaining legacy I&C systems is not the least-cost option; all I&C functions can be migrated to two standard platforms (safety and non-safety); licensing of safety I&C upgrades is not the barrier it was once thought to be; significant operator-performance improvement is available with control room digital technology; and future I&C obsolescence can be cost-effectively avoided with a life-cycle strategy.