MPR Associates is an American engineering services firm founded in Washington, DC in September 1964 by three former Naval Reactors engineers and headquartered in Alexandria, Virginia, whose engineers co-authored the SPARC shielding proceedings.
Harry Mandil, Robert Panoff and Theodore Rockwell left Admiral Rickover's naval nuclear propulsion program after fifteen years to start the firm, and its early portfolio ran to plant design and evaluation, reactor core and component design, containment and 📝shielding work, and the Navy's SUBSAFE submarine safety program. MPR provided technical leadership on the Loss-of-Fluid Test facility in 1973, was the first to visually observe failed fuel at Three Mile Island Unit 2 in 1982, and in 1990 removed fifteen metal specimens from that reactor's lower head to determine how molten fuel had interacted with the vessel steel. The firm moved to 320 King Street in Old Town Alexandria in 1992 and now works across nuclear technologies, power and energy, transmission and distribution, health and life sciences, and federal programs, with offices added in Houston, Connecticut and the Boston area.
Its appearance in the Commonwealth Fusion Systems record is 📝The SPARC Neutronics and Shielding Papers, seven Transactions of the American Nuclear Society proceedings from 2022 and 2023 carrying five MPR-affiliated authors. Ryanne Kennedy is a co-author on six of the seven, including the variance-reduction study led by 📝Andrea Saltos; Michael Saitta led a deterministic analysis of a deep shield with penetrations, and Joshua Jones led the neutronics models for evaluating shielding in the 📝SPARC facility. By the 2024 Review of Scientific Instruments SPARC diagnostics overviews, Kennedy is deposited with a Commonwealth Fusion Systems affiliation rather than an MPR one.
The public record ends there. MPR's own site describes no 📝fusion practice — its nuclear technologies page lists licensing strategy, core physics support, criticality safety analysis, ASME code work and component design, and the word appears nowhere on the firm's site or in its news archive. What is documented is a nuclear and mechanical engineering services firm whose staff contributed to SPARC's neutronics and shielding analysis.