Solving Sellafield’s 4 Ds problem

The Nuclear Regulatory Commission has issued the draft report, Consolidated Decommissioning Guidance, Characterization, Survey, and Determination of Radiological Criteria (NUREG-1757, Volume 2, Revision 2), with a request for comments by February 8.

NUREG-1757, which is intended for use by applicants, licensees, and the NRC staff, was last updated in 2006. This latest revision addresses lessons learned and experience gained from the review of license termination plans, decommissioning plans, and final status surveys for licensees undergoing license termination since then.

Notice of the draft NUREG was published in the December 8 Federal Register.

The Deepsea Delta oil-drilling platform in the North Sea. Photo: Wikimedia Commons

Nuclear decommissioning projects can benefit from the lessons learned in the fossil fuel industry, according to a December 8 Reuters Events post that draws heavily from an article published in the ANS magazine Radwaste Solutions.

Reuters reporter Paul Day interviewed the authors of “Tapping Nonnuclear Knowledge,” which appeared in the Fall 2020 issue of RS and examines research being done on cross-sector learning between nuclear and oil and gas decommissioning projects, particularly the mega projects of decommissioning nuclear power plants and offshore oil rigs.

Orano's Alain Vandercruyssen signs a cooperation agreement with KHNP on December 4. Photo: ORANO

With the signing of a cooperation agreement by Orano and Korea Hydro & Nuclear Power at KHNP’s headquarters in Gyeongju on December 4, France and South Korea are poised to enhance collaboration in the decontamination and decommissioning of nuclear facilities, particularly in South Korea and Europe.

Orano said that the collaboration will give it access to the expertise of KHNP engineers, as well as to KHNP’s network of providers of nuclear engineering services, particularly in the fields of robotics, process industrialization, and quality.

KHNP, in return, will benefit from Orano’s experience in preparing and carrying out nuclear dismantling, with the company providing technical assistance and supplying skills and training. South Korean engineers will be included in the Orano dismantling and services teams.

The Nuclear Regulatory Commission has approved the transfer of the license for Unit 2 of the Three Mile Island nuclear power plant from FirstEnergy Companies to TMI-2 Solutions, a subsidiary of Utah-based EnergySolutions. The approval, announced on December 2, is effective immediately, and the license will be amended to reflect the new ownership once the sale of TMI-2 is completed.

Indian Point’s licenses will transfer to Holtec for decommissioning after the plant shuts down in 2021. Photo: Entergy Nuclear

The transfer of the Indian Point nuclear power plant licenses from Entergy to Holtec International, as owner, and Holtec Decommissioning International (HDI), as decommissioning operator, has been approved by the Nuclear Regulatory Commission. The license transfers follow the transfer of the licenses of the Oyster Creek nuclear plant from Exelon and the Pilgrim plant from Entergy to Holtec in mid-2019. As with the Oyster Creek and Pilgrim plants, Holtec and HDI intend to expedite the decommissioning and dismantling of Indian Point.

Indian Point’s three pressurized water reactors are located in Buchanan, N.Y., approximately 24 miles north of New York City. Units 1 and 2 have been permanently shut down, in 1974 and 2020, respectively, and Unit 3 is scheduled to be shut down in April 2021. The license transfer also includes the plant’s independent spent fuel storage installation (ISFSI).

Diakont technicians prepare an NDE inspection robot for deployment into a diesel tank. Photos: Diakont

Robotics and remote systems have been used for supporting nuclear facilities since the dawn of the atomic age. Early commercial nuclear plants implemented varying levels of automation and remote operation, such as maintenance activities performed on the reactor pressure vessel and steam generators. Over the past several decades, there has been a steady progression toward incorporating more advanced remote operations into nuclear plants to improve their efficiency and safety. One of the primary forces driving the adoption of robotic tooling in U.S. nuclear power plants is money.

The economic model for the U.S. operating fleet has changed considerably over the past 10 to 12 years. Regulations in the nuclear industry have rarely decreased and, more often than not, have increased. This has led to nuclear plants in certain energy markets being hindered financially and thus needing to find ways to optimize their operations to do more with the resources they have. At the same time, the reliability and flexibility of robotics and automated systems have been increasing while their costs have been decreasing, making robotic systems much safer and more available to use. This has helped drive utilities to explore new ways of using robotics to overcome the obstacles they are facing. One of the obstacles that power plants have been tackling has been shortening the duration of their refueling outages to decrease their costs and increase their revenue.

The Pilgrim nuclear power plant was shut down in May 2019. Photo: Entergy Energy

The Nuclear Regulatory Commission has denied a request by the antinuclear group Pilgrim Watch for a hearing in the transfer of the Pilgrim nuclear power plant’s license from Entergy to a subsidiary of Holtec International for decommissioning. The NRC commissioners issued the order denying Pilgrim Watch’s petition to intervene and request a hearing on November 12.

Pilgrim Watch submitted its petition against the transfer of Pilgrim’s license from Entergy to Holtec Decommissioning International in February 2019. The NRC staff, however, approved the transfer in August 2019, while the petition was still under review. NRC regulations allow staff to approve a license transfer under the condition that the commissioners may later move to “rescind, modify, or condition the approved transfer based on the outcome of any post-effectiveness hearing on the license transfer application.”

A separate petition against the license transfer submitted by the state of Massachusetts was withdrawn in June, following a settlement agreement between the state and Holtec.

Pilgrim permanently ceased operations in May 2019. Holtec plans to decommission the plant (with the exception of the independent spent fuel storage installation) on an eight-year schedule to permit partial site release by the NRC.

The Zephyr system uses probes for steam generator inspections. Photos: APS

The Palo Verde Nuclear Generating Station, a three-unit pressurized water reactor plant operated by Arizona Public Service Company, has started using an inspection technology relatively new to the nuclear industry. The technology, called smart pigs (an acronym for “piping inline gauges”), has previously been employed by oil and gas companies for inspecting and cleaning underground pipes. After testing and analyzing smart pig products from several companies, Palo Verde’s underground piping consultant, Dan Wittas, selected a smart pig suitable for navigating the tight-radius bends in the plant’s spray pond piping. The spray pond system consists of piping, a pump, and a reservoir where hot water (from the Palo Verde plant) is cooled before reuse by pumping it through spray nozzles into the cooler air. Smart pigs work by using the water’s flow through the piping to move an inspection tool within the pipe itself. The technology replaces the previous method of pipe inspection, in which various relatively small sections of piping were unearthed and directly inspected, and were considered to be representative examples of the overall piping condition. In contrast, the smart pigs obtain corrosion levels for the length of piping traveled through and allow a corrosion baseline to be established.

Ratliff

Harris

When Floyd Harris began working at Duke Energy’s Brunswick nuclear plant about 24 years ago as a radiation protection technician, robotics and remote monitoring were considered tools for radiation protection and nothing more. Now, teams from across the site, including engineering, maintenance, and operations, rely on the system of robots and cameras Harris is responsible for. “If you want to put those technologies under one umbrella,” says Harris, who now holds the title of nuclear station scientist, “it would be monitoring plant conditions.”

That monitoring is critical to effective plant maintenance. As Plant Manager Jay Ratliff explains, the goal is to “find a problem before it finds us” and ensure safety and reliability. Nuclear News Staff Writer Susan Gallier talked with Ratliff and Harris about how robotics and remote systems are deployed to meet those goals.

At Brunswick, which hosts GE-designed boiling water reactors in Southport, N.C., ingenuity and hard work have produced a novel remote dosimetry turnstile to control access to high-radiation areas, an extensive network to handle data from monitoring cameras, rapid fleetwide access to camera feeds to support collaboration, and new applications for robots and drones.

The Nuclear Regulatory Commission has rejected a petition by Three Mile Island Alert (TMIA) challenging Exelon’s request to revise its site emergency plan for the closed Three Mile Island nuclear power plant in Pennsylvania. Exelon submitted a request to the NRC to amend its TMI-1 license to reflect the reduced risks of the defueled reactor, which was permanently shut down in September 2019.

In an order issued on October 8, the NRC commissioners upheld a decision by an NRC Atomic Safety and Licensing Board denying TMIA’s petition to intervene and request a hearing in the license amendment request. That decision, issued on January 23, 2020, found that the antinuclear group had not established standing in the case and that its contentions were inadmissible.