Studying human error to improve safety

Los Alamos National Laboratory’s Mike Petrowski looks at the “why” to understand — and prevent — mistakes

October 19, 2023

Mike Petrowski works with employees at all levels of the Lab to help them prevent consequential mistakes.

Mike Petrowski, who works in performance assurance at Los Alamos National Laboratory, wants to understand the “why” behind our mistakes — at least the ones with serious consequences.

So in 1979, outside Harrisburg, Pennsylvania, when the Three Mile Island nuclear power plant reactor partially melted down and led to the release of radioactive material into the environment, experts leading the root cause analysis were inadvertently paving the way for Mike’s career.

Mike was only in high school at the time, but later, his career in the nuclear industry would intersect with the event, since Three Mile led to the U.S. Nuclear Regulatory Commission’s laser focus on the human element of disasters — or why people do what they do in high-hazard scenarios and how to create error-tolerant environments accordingly.

The field would become known as human performance improvement, which eventually became Mike’s professional purview. 

Creating an error-tolerant environment

With his natural curiosity, human performance — defined as “understanding how people interact with plants, processes and each other as part of a system to help manage risk and keep safe” — was an instant fit for Mike, who entered the field in the early 2000s amid a 30-year stint in the nuclear power industry, and then continued his journey when he moved to Los Alamos National Lab in 2016.

“Think about the variety of things we do here and the outcomes of those things,” Mike says, referring to the various groups he works with Lab-wide as well as the many inherent risks he works to mitigate.
Why people make mistakes

In Mike’s work with nearly every group at the Lab — including management and boots-on-the-ground employees — he leads trainings to raise awareness of what drives human error so it’s avoided. He also leads Learning Teams to evaluate factors in low-level incidents, with the intention of preventing a trend toward high-level incidents.

This methodology was credited by the Department of Energy in 2016, combined with ergonomic and process engineering changes, as a best practice for engaging employees and reducing injuries from 10-12 per year to three per year over a three-year period at one Lab facility.

Learning Teams formed after a realization that fact-finding missions, which occur after abnormal events to identify contributing deficiencies that should be avoided down the road, were found to have an unproductive intimidation factor. Fact findings typically involve all levels of management, including DOE site representatives and the Defense Nuclear Facilities Safety Board. 

“One of the main things I like about human performance is it’s about the people,” Mike says. “How do we make people successful in what they’re doing? Because no one likes to make mistakes. No one likes consequences. We’d rather be successful at what we do. Human performance improvement tools take human fallibility into account to help us have successful outcomes.”

The variety of the Lab’s work appeals to Mike because, according to human performance principles, humans aren’t good with boredom, repetition or distraction. It’s in those environments that people make mistakes. Fortunately, the nuclear industry now seeks out processes and systems so mistakes can be made safely in such environments, without extreme consequences.

“We make nuclear isotopes used in the medical industry. We learn about explosives. We’ve been involved in COVID-19 — tracking and projecting where it would spread to help local governments respond appropriately. We run the Mars rover from an office near Ashley Pond. We’re making pits,” Mike says, summing up some of the Lab’s challenging activities.


In training employees to prevent undesirable outcomes — primarily in jobs related to weapons research and production — Mike strives to understand and address the human element of mistakes.

“Humans are more fallible in error-likely situations, like when we’re in a hurry because of time pressures,” Mike says. “If we understand human nature, we appreciate what human performance improvement tools are trying to do for us.”

“One of the tools we use at the Lab is adherence to procedures,” Mike adds. “When we’re using procedures, we place-keep, just like you do at the grocery store when you mark things off your list so you don’t miss something or duplicate it.”

Another important tool, Mike says, is pausing when unsure. 

“It’s hard for people to stop,” he says. “We want to accomplish the outcome. So we try to overcome barriers to achieve, but that’s not always the best route. In our line of work, we don’t want to be guessing or trying. We want to be certain and know what to do.”

Applying curiosity wherever he goes

It’s not just the Lab and its various areas of excellence that Mike enjoys exploring. Most weekends and holidays, he takes to the open road and enjoys RV life with his wife, Jolene. He’s been to every state but three, and included on his list of retirement options is going full-time in his travel trailer.

Mike also contributes to the Lab’s Active Bystander Employee Resource Group, which aims to create a healthy workplace culture by empowering employees to reinforce positive behaviors and address negative ones by speaking up. 

In addition, Mike is lead observer for the Laboratory Operations Management Academy (LOMA) workshop — which teaches higher-level managers to understand and support first-line managers in internalizing and modeling Safe Conduct of Research principles — as well as its companion workshop for supervisors, the Laboratory Operations Supervisor Academy (LOSA). Mike is also lead observer for the LOSA Grad program.

In what’s left of his time, Mike contributes to the Energy Facility Contractors Group, whose mission is to “maximize DOE and NNSA mission success by sharing best practices and information.” Mike serves as lead for the group focused on human performance improvement.  

“As a nationally recognized HPI expert, Mike is highly sought after as a speaker and trainer on the subject and has been instrumental in sharing and incorporating HPI principles at LANL and beyond,” says Aimee Blanchard, his group leader. “Mike is a passionate professional who cares deeply about reducing accidents and events and keeping people safe.”