Next-Generation Monitor Combats Nuclear Threats

As a competitive skier in his youth, James Ely learned the rewards of perseverance. Now, he is utilizing his focus and steadfastness to develop a next-generation online enrichment monitor nearly 10 years after reviewing the specifications of the first one.

In August, Ely and a team from the Pacific Northwest National Laboratory (PNNL) conducted a site visit for a test at the International Atomic Energy Agency (IAEA) Centre of Excellence for Safeguards and Non-Proliferation in the United Kingdom.

The PNNL-developed UF6 Gas Enrichment Sensor (UGES) prototype is the next generation of a previous enrichment monitoring device—namely the Online Enrichment Monitor (OLEM). UGES will increase the accuracy of uranium measurements and reduce analysis time and cost in comparison to its predecessor. This new device continues to support the goals of ensuring nuclear materials are used for peaceful purposes and safeguards against the threats of nuclear weapons from foreign adversaries.

Inception of the invention

The OLEM measures amounts of gaseous uranium, also referred to as uranium hexafluoride or UF6, as it flows through the pipes of an enrichment plant. UF6 is a critical component of the enrichment process for fuel in nuclear power plants and in nuclear weapons.

In 2016, the world was introduced to the first OLEM device when the IAEA installed the device at the Natanz Fuel Enrichment Plant in Iran. It was created by a research team led by Oak Ridge National Laboratory (ORNL) and Los Alamos National Laboratory, with support from PNNL.

At the time, Ely, a nuclear physicist, was on leave from PNNL to complete a 3-year assignment with the IAEA Division of Safeguards Technical and Scientific Services.

After joining the IAEA in 2013, Ely led the team that assessed, reviewed, and evaluated the OLEM to ensure its viability. Little did he know that he would be leading the creation and testing of the next-generation OLEM prototype nearly 10 years later.

“I led the team at the IAEA that took the ORNL prototype through an engineering development cycle to limited production units and was instrumental in the deployment, installation, and commissioning of the system,” he said. “It was one of my professional highlights to see it through the IAEA process.”

Monitoring uranium use 

Being remarkably familiar with the OLEM system gave Ely an advantage in understanding its strengths and weaknesses. He said the current OLEM can be affected over time from deposits in the pipe, leading to increased uncertainties in measuring UF6 gas enrichment. Additional time and effort are needed to analyze the data of the deposit effects on the current OLEM.

Weighing less than 30 pounds and smaller than a briefcase, PNNL’s new UGES prototype addresses both limitations of calculating enrichment deposits and timely data analysis.

“The signals (for the gas and the deposits) are the same and the current OLEM data can be used to estimate the deposit contribution and subtract it out,” said Ely. “But this process requires additional data analysis and expert data analysts, and it results in more uncertainty in the enrichment values, making it a two-step data processing approach.”

The new prototype uses an array of detectors with two different collimators, replacing the single gamma ray detector in the current OLEM model. The different collimators allow the UGES prototype to provide real-time measurements of the UF6 gas and deposits separately, reducing analysis time and increasing precision.

In addition, this next-generation OLEM is about half the size and weight of the current OLEM, which allows for easier installation and maintenance.

Using this modified, dual-collimator approach with an array of cadmium-zinc-telluride detectors, the UGES prototype has been built and tested in a lab environment at PNNL.

“After testing the UGES at the Centre and demonstrating the improved capability, we hope the prototype will be turned into an engineered system in the field,” said Ely. “The field data will be significant to show that it will work properly when installed. We want to work closely with the IAEA to develop a system that could be authorized and deployed for use in their safeguards mission.”

Eye on the prize

For Ely, having a penchant for patience and perseverance were rooted in his upbringing on a cattle ranch and then as a competitive cross-country skier.

He spent years competing on snow slopes across the Pacific Northwest before he turned his focus to engineering and physics. He credits a nuclear physics class in college for steering him toward a career in national security.

Ely, who joined PNNL in 2002, has dedicated his career to nuclear nonproliferation and has been recognized by the U.S. Department of Energy.

“I’ve seen firsthand how valuable the OLEM technology has been for the IAEA in supporting nuclear safeguards for a safer world,” said Ely. “To develop and test a next-generation prototype is definitely professionally rewarding, as well as benefiting the IAEA and the safeguards mission.”

The testing of the UGES prototype will occur during the upcoming months, allowing time for deposits to build up in the pipes. The researchers at PNNL will assess the performance of the equipment and analyze the data, working collaboratively with the IAEA.