NRC eyes advanced reactor oversight program for new reactors

For roughly 25 years, the Nuclear Regulatory Commission has used the Reactor Oversight Process (ROP) to inspect and evaluate the existing fleet of operating nuclear power plants. With the likelihood there will be new nuclear power plants with reactor designs unlike those of the current fleet, the NRC is looking to adopt something similar for these new entries.

The regulatory agency held a public meeting on Wednesday to share more about its early plans to develop an Advanced Reactor Oversight Process, or AROP. The meeting provided NRC staff an opportunity to engage the public and stakeholders about the AROP and introduce this potential addition. As of now, discussions are preliminary, and no final regulatory decisions have been made.

About the proposal: If implemented, the AROP would build on the Advanced Reactor Construction Oversight Process (ARCOP), the framework applied for the construction of new nuclear facilities. Phil McKenna, deputy director of the NRC's Office of the Chief Nuclear Reactor Inspector (CNRI), said they are working on AROP now because the ADVANCE Act mandates the agency to complete its processes for microreactors by next summer.

"It's more efficient for us to do all advanced reactors and not just do microreactors," McKenna said.

NRC staff on Wednesday said much like ARCOP, the proposed AROP would revolve around five principles: a framework that is risk informed, performance based, technology inclusive, scalable, and licensing neutral that can be applied across new nuclear reactor and facilities while maintaining safety in its focus. The elements of any advanced reactor oversight program should continue to rely on performance monitoring, enforcement, and assessments.

According to Odunayo Ayegbusi, senior reactor operations engineer with the CNRI, the NRC gathered early industry input on the topic over the last couple of years. Feedback suggested an advanced reactor oversight program should do the following:

• Leverage research and test reactor oversight concepts.
• Account for novel features like prefabrication, simple designs, and remote capabilities.
• Have simplified methodologies.
• Provide a tech-inclusive alternative.
• Perform targeted inspections when performance indicators cross a certain threshold.
• Reduce the frequency of routine on-site inspections, should performance indicators continue demonstrating effectiveness.

A potential AROP also should leverage the existing ROP framework, which is based on three performance areas split into seven cornerstones: initiating events, mitigating systems, barrier integrity, emergency preparedness, public radiation, occupational radiation, and security.

Ayegbusi said the new framework could leverage this existing framework into something that is brand new, is identical to the ROP framework, or is a mix of old and new.

Concepts for AROP envision a matrix where the cornerstones and cornerstone-specific thresholds determine an advanced facility's level of oversight. According to the concepts presented on Wednesday, inspections would increase as oversight tiers increase in each cornerstone.

What happens next: Given that an AROP has yet to be finalized, questions remain on the scope of the proposal. As presented, AROP would target a broad range of reactor designs, ranging from non-light water reactors to small modular reactors to microreactors. For instance, one attendee on Wednesday asked whether the current fleet of AP1000 reactors at Vogtle and any future AP1000s would fall under the established ROP or AROP.

"The current existing AP1000 designs are under the ROP," said Ayegbusi. "As we develop the AROP, we will take that into consideration where the AP1000s should fall eventually."

Wednesday's meeting provided an early timeline of when to expect certain items regarding an AROP. By January, NRC staff should be finalizing high-level strategies and guidance. By March, staff will have a draft SECY on the topic. The SECY will be submitted to the Office of the Executive Director for Operations in April, with the SECY ultimately submitted to the NRC commissioners in May.

NRC staff said there will be future workshop sessions on AROP in the near future.