News Release > Entergy Nuclear announces leadership moves at plants, headquarters

For Immediate Release

Entergy Nuclear announces leadership moves at plants, headquarters


(From top, L-R) Joe Sullivan, Doug Pehrson, Brad Wertz, Mandy Halter, Dave Oertling, John Ferrick
(From top, L-R) Joe Sullivan, Doug Pehrson, Brad Wertz, Mandy Halter, Dave Oertling, John Ferrick

Transitions are critical to company’s continued success

JACKSON, Miss. – Entergy Nuclear recently announced several leadership moves at its nuclear plants in Arkansas and Louisiana, as well as its headquarters operations in Jackson, Miss.

Joe Sullivan, Entergy site vice president at Arkansas Nuclear One in Russellville, has been named site vice president at Waterford 3 Steam Electric Station in Killona, La. Sullivan replaces John Ferrick who will transition to fleet vice president, outage services at company headquarters in Jackson, Miss.

Doug Pehrson, currently Entergy general manager of plant operations at ANO, becomes the new site vice president at ANO, while Brad Wertz will take on the general manager role.

Concurrently, Mandy Halter, general manager at Waterford 3 in Killona, La., will transition to a company leadership role in Jackson, Miss. representing the nuclear fleet. Dave Oertling, currently Waterford 3 regulatory and performance improvement director, will become the new Waterford 3 general manager.

“I want to congratulate each of these outstanding nuclear professionals as they take on their new roles.  I also want to thank them for their many contributions in their former roles,” said John Dinelli, Entergy Nuclear chief operating officer. “Entergy values empowerment and engagement across our workforce, and the fact that our people can step into new and important roles is critical to our continued success.”

Joe Sullivan

Sullivan has held senior leadership roles, including the general manager, fleet operations at Echelon, Entergy’s nuclear headquarters, and general manager of plant operations at Cooper Nuclear Station in Brownville, Neb. Prior to coming to Entergy, Sullivan served in various positions of increasing responsibility at three nuclear sites in the northeast. He was also a U.S. Nuclear Regulatory Commission license examiner and inspector, and was an on-shift senior reactor operator at Calvert Cliffs and Salem generating stations in Maryland and New Jersey respectively. He is a graduate of the U.S. Naval Academy.

Doug Pehrson

Prior to assuming the general manager role, Pehrson was the operations director and senior manager of maintenance at ANO. Throughout his career, Pehrson held several positions in operations at ANO, including reactor operator, shift technical advisor, control room supervisor, shift manager and Unit 1 operations manager shift. Pehrson, who served in the U.S. Navy, holds a bachelor’s in nuclear engineering technology from Thomas Edison State University. He holds a master’s in business administration from LSU.

Brad Wertz

Before taking his current assignment, Wertz was the general manager at Grand Gulf Nuclear Station in Port Gibson, Miss., worked in regulatory assurance and was senior manager, operations. In 2006, Wertz joined Entergy at the James A. Fitzpatrick Nuclear Power Plant in New York. He began his career in 2001 working for Bechtel-Bettis Atomic Power Laboratories in Pittsburgh, Pa. Wertz holds a bachelor’s degree in chemical engineering from Bucknell.

Mandy Halter

Halter joined Entergy in 2017 as vice president of regulatory assurance after a career with the U.S. Nuclear Regulatory Commission. With that agency, she held various positions, including senior resident inspector stationed at nuclear power plants, working up to policy advisor to the presidential-appointed NRC chair. Prior to the NRC, Halter served for 11 years as an officer in the U.S. Nuclear Navy, where she drove the largest warships, operated a nuclear reactor onboard an aircraft carrier, and trained future officers at two accredited universities. Halter earned a bachelor’s in chemistry from the Naval Academy and two master’s degrees, one in engineering management from Old Dominion University and the other from Villanova University in business administration. In her career with Entergy, Halter also worked in regulatory assurance and was acting general manager at Grand Gulf, and was general manager at Waterford 3.

Dave Oertling

Oertling returned to his Louisiana roots in 2022 when he joined Waterford 3 as the director of regulatory and performance improvement. Previously, Oertling served as the director of operations at ANO. Oertling began his Entergy career in 1997 as a non-licensed operator and went on to become a qualified reactor operator, operations training instructor, control room supervisor, shift manager and assistant operations manager. He was a senior license holder for ANO Unit 2 from 2019 to 2020. Prior to his career at Entergy, Oertling served eight years in the United States Navy.

About Entergy

Entergy Nuclear, headquartered in Jackson, Mississippi, is a subsidiary of Entergy Corporation. Entergy Nuclear owns, operates and supports a fleet of five reactors in four locations, generating enough clean, carbon-free electricity to power millions of homes. Entergy (NYSE: ETR) is a Fortune 500 company that powers life for 3 million customers through our operating companies in Arkansas, Louisiana, Mississippi and Texas. We’re investing in the reliability and resilience of the energy system while helping our region transition to cleaner, more efficient energy solutions. With roots in our communities for more than 100 years, Entergy is a nationally recognized leader in sustainability and corporate citizenship. Since 2018, we have delivered more than $100 million in economic benefits each year to local communities through philanthropy, volunteerism and advocacy. Entergy is headquartered in New Orleans, Louisiana, and has approximately 12,000 employees. Learn more at and follow @Entergy on social media. #WePowerLife