DOUGLAS M. CHAPIN (1940-2024)

BY M. CORRADINI

DOUGLAS MCCALL CHAPIN, an international leader in nuclear reactor engineering and safety and retired principal officer of MPR Associates, Inc., died on May 3, 2024. He was 83.

Doug was born in Atlanta in 1940 to Lloyd Walter Chapin and Carolina McCall Chapin. He attended North Fulton High School, where he played basketball and excelled in science and mathematics. He attended Duke University as a Navy Reserve Officers’ Training Corps student and earned a bachelor’s degree in electrical engineering in 1962. While serving in the Navy, he earned a master’s degree in applied science from George Washington University. After retiring from the Navy, he went on to earn a Ph.D. in nuclear studies in chemical engineering from Princeton University in 1968.

Doug was an industry leader and international expert in power engineering. During his Navy years, he worked as part of the Naval Reactors Program to accelerate the development of the “Nuclear Navy” under Admiral Hyman Rickover (NAE 1967). After leaving the Navy, he joined the Washington, D.C.-area engineering firm MPR Associates, Inc., and began a five-decade career that took him around the globe. He eventually rose to lead the company as a principal officer.

His influence on MPR was outsized. When the firm’s founders chose to retire, Doug seamlessly stepped into the role of principal officer. As the industry holder of the Rickover legacy of excellence, MPR carries high expectations for the technical and engineering performance of its staff. Doug embraced that responsibility — not only maintaining the legacy but strengthening it and empowering others at MPR to do the same. During his tenure as principal officer, MPR grew fourfold. Under his leadership, the company transitioned from a boutique firm serving a handful of clients to a nationally recognized leader in technical and engineering services for the U.S. nuclear industry. MPR regularly supported every nuclear power plant in the country, as well as all major nuclear steam supply system vendors.

Recognizing the evolving energy landscape and the changing needs of clients and society, Doug led MPR’s expansion beyond nuclear energy. The firm broadened its work to include all forms of power and energy, strategic engagements with the U.S. Department of Energy (DOE), Department of Defense, and Department of Homeland Security, and even breakthroughs in the health and life sciences sector—developing innovative medical products. He was not only the longest-serving principal officer in MPR’s history; his vision and leadership were instrumental to the firm’s evolution and continued success during a period of transformation.

He set the standard for and served as a model “professional engineer” in every sense. His leadership and mentoring were invaluable to the next generation of MPR leaders, whom he continually challenged to strive for excellence and to deliver impactful solutions to meet society’s greatest needs. Ted Rockwell (NAE 2001) — the “R” in MPR — famously said nearly 60 years ago: “We have made exceptional efforts to bring into the company only persons with outstanding qualities or potential, both as engineers and as human beings.” Doug was a living example of that vision, and his impact on MPR cannot be overstated.

Doug’s contributions to commercial nuclear reactor safety were immeasurable. He served as MPR’s project leader for the design, construction, and testing of the Loss of Fluid Test (LOFT) facility in Idaho. The extensive research conducted at LOFT — sponsored first by the U.S. Nuclear Regulatory Commission and later by the Organization for Economic Cooperation and Development (OECD) — provided critical insights into large break loss-of-coolant accident phenomena and the effectiveness of emergency core cooling systems. LOFT provided key benchmark data that validated the thermal hydraulic safety analysis computer codes used by nuclear engineers worldwide.

Doug was also in high demand as an advisor on nuclear power operations as well as research and development for the DOE and international organizations. He served as a longtime member of the DOE’s Nuclear Energy Advisory Committee and its subcommittee on nuclear reactor technology for more than a dozen years. That group played a crucial role in shaping the DOE’s long-term research plans for advanced reactor fuel, instrumentation, and component technologies. In 2011, he was invited to join an international group tasked with developing safety recommendations for the Fukushima Daiichi nuclear reactor site in Japan after it was severely damaged in an earthquake and tsunami. He also served on and led numerous technical committees, review panels, and advisory boards within the nuclear engineering field.

Among his many notable awards and achievements, Doug was elected to the National Academy of Engineering in 2002. In 2014, he received the prestigious Don Miller Award from the American Nuclear Society, recognizing outstanding contributions to engineering, research and development, licensing, or project achievements in the fields of nuclear instrumentation, control, and human-machine interface technologies worldwide.

Doug met “Joanie” Stewart during a freshman social at Duke University. They married in 1962 and established a loving home in Falls Church, Virginia. While they adored their children and grandchildren, their shared passion was traveling the world—visiting more than 40 countries over the decades. Among their favorite adventures were exploring Machu Picchu, going on African safaris, swimming in the Amazon River, and traveling extensively through New Zealand and Australia.

Doug overcame polio at a young age, which fueled a lifelong commitment to staying active. He was an avid sportsman, playing basketball in his youth, long-distance bicycling in mid-life, and walking daily in his later years. He enjoyed all local sporting events, but it was Major League Baseball’s Washington Nationals who truly captured his heart after they arrived in D.C. in 2005. Their World Series championship in 2019 brought him particular joy.

Doug faced life’s challenges with perseverance, humility, and quiet effectiveness. He embodied the highest ideals of a professional engineer. His friends and colleagues are deeply grateful for the honor of having known and worked alongside him. He will be greatly missed.

Doug is survived by his beloved wife of more than 60 years, Joan Kay (Stewart); his brother, Lloyd Walter Chapin Jr., and wife, Louise, of St. Petersburg, Florida; his children, Douglas McCall Jr. of Minneapolis; Jennifer Kay of Gainesville, Virginia; Timothy Stewart of Tallahassee, Florida; and Andrew Vincent and wife, Regina, of Fairfax, Virginia. “Grandpa Doug” is also survived by 11 amazing grandchildren: Ellen, Sarah, Sydney, Christopher, Justin, McCall, Liam, Oliver, Tamsin, Eamon, and Rhys.