Principal/Lead Nuclear Engineer

OverviewAs a Principal/Lead Nuclear Engineer at MPR, you'll work across advanced fission reactors, operating nuclear plants, and research facilities — bringing your expertise to a diverse range of technologies and reactor concepts. Consulting means no two projects are the same: different clients, different challenges, different problems to solve. It's the kind of breadth that keeps the work engaging and your skills continuously growing.Your role will primarily focus on providing subject matter expertise and mentorship to the next generation of nuclear engineering experts and leveraging your experience and connections to capture cutting edge project for MPR. Specifically, your expertise will be invaluable to achieve:Serving as a subject matter expert on a wide array of nuclear engineering projectsHelp expand MPR’s network within the nuclear industry, andProvide mentorship and guidance to the next generation of nuclear engineers.Because of MPR’s role as trusted partner for virtually all cutting edge advanced nuclear suppliers, project workload will vary significantly over time. Some examples of the types of projects you could support include:Independent evaluation of advanced reactor designs (molten salt, sodium-cooled fast reactors, high-temperature gas reactors, microreactors)Fusion device thermal and radiological designOperating nuclear plant engineering support and analysis (PWR, BWR fleet)Research and test facility design and safety analysisLoss of coolant accident analysis and source term evaluation across reactor typesNovel fuel form and component qualification for multiple technologiesCriticality safety evaluations for DOE facilitiesIndependent, technology comparison studies for utilities and investorsThe role requires deep expertise in or an ability to quickly master several nuclear engineering related topics, including neutronics, thermal hydraulics, shielding, fuel and nuclear materials, and radiological consequence evaluation combined with strong communication skills, adherence to best practices, and an eye for growing MPR's portfolio.Duties/ResponsibilitiesTypical duties for the role will vary based on project and workload at MPR, but will likely include an array of the following:Technical ExpertiseDevelop design/analytical solutions for complex technical challenges across diverse reactor technologies andOversee MPR engineers performing neutronics simulations and core design: criticality safety evaluations, critical core configurations, fuel cycle management, activation calculations, radiation detection and shielding analyses: alarm setpoint determination, shielding optimization, ALARA implementation, dosimetry calculationsReview and validate work performed by other MPR engineersChallenge vendor assumptions and verify results using first principles thinkingBusiness DevelopmentIdentify and pursue opportunities to grow MPR's project portfolio with existing and new clientsTake a lead role in client and stakeholder interactions by effectively communicating technical resultsMentorshipCoach and mentor engineers through execution of complex nuclear analysis work spanning different technical domains and lead by exampleWork with MPR leadership to identify pathways for junior engineers to growQualificationsCompetitive candidates will have most of the following:EducationBachelor's degree in Nuclear Engineering or Mechanical Engineering with nuclear concentrationAdvanced degree (MS or PhD) is a plus but not requiredTechnical Experience15+ years of nuclear engineering experience with demonstrated expertise across multiple technical areas (neutronics, thermal-hydraulics, radiation detection, shielding, radiological consequence evaluation)Proficiency with common nuclear engineering software: MCNP, SCALE, ORIGEN, RELAP, or equivalent toolsFamiliarity with both light water and non-light water reactor designs, or fusion device thermal and radiological designsExperience developing test plans for novel nuclear designs (new fuel forms, components, etc.)Strong understanding of NRC regulations and guidance for reactor analysis (e.g., loss of coolant accident analysis methods, source term, licensing basis)Strong analytical skills grounded in first principles—not just software proficiency or vendor-specific methodologiesAbility to work across engineering disciplines to evaluate all facets of technical problemsDeep understanding of nuclear physics, thermal-hydraulics, materials behavior, and radiological phenomenaLeadership & Communication SkillsExcellent verbal and written communication skills—you can explain complex nuclear phenomena to clients, regulators, and non-specialistsExperience presenting at industry conferences and engaging with external audiencesProven ability to oversee and mentor less experienced engineers and building teamsAbility to manage multiple concurrent projects across different reactor technologies and teamsDemonstrated success building and maintaining client relationshipsExperience identifying and pursuing new business opportunitiesMotivated to tackle unfamiliar problems and take on new responsibilitiesPersistent, questioning attitude—and the ability to accept that in othersStrong time management and organizational skillsReceptive to constructive feedback and continuous improvementPreferred ExperienceSimilar lead/subject matter expertise from previous job experienceDirect experience with NRC licensing processes and regulatory interactionsPublished technical work or conference presentationsTrack record of successful business development in the nuclear industryExperience evaluating multiple competing reactor technologiesRequiredThis position must meet Export Control compliance requirements, therefore a “US Person” as defined by 22 C.F.R. § 120.15 is required. “US Person” includes US Citizen, lawful permanent resident, refugee, or asylee.Locations: Alexandria VA (HQ), East Lyme CT, Burlington MA, or Salt Lake City UTPosition Type: Full-time, exemptTravel: 10-20% as required by project assignments, including client sites, test facilities, regulatory meetings, and visits between MPR officesWork Environment: Collaborative and technically rigorous—you'll lead multiple concurrent projects across different reactor technologies, mentor engineers across technical domains, and continuously expand your expertise while maintaining independence from vendor-specific approachesAbout MPRFounded in 1964, MPR Associates provides independent engineering and consulting services to clients in the power and energy, federal, and life sciences sectors. The firm operates throughout the United States and internationally, making challenging projects successful by delivering safe and reliable technical solutions across the entire project lifecycle. Our independence from any single technology vendor or corporate parent allows us to provide objective technical advice and maintain broad expertise across the nuclear industry.What truly sets MPR apart from our peers is:The Work: Work across multiple reactor technologies—advanced fission, fusion, operating plants, and research facilities—rather than narrowing into one vendor's design. You'll serve as an independent technical authority using first-principles problem-solving, not repetitive vendor-specific calculations. A broad client base means direct interaction with reactor developers, plant owners, regulators, and research institutions—and insulation from the fate of any single technology. You'll also have autonomy to identify and pursue new projects that align with your expertise and interests.The Culture Technical rigor and first-principles thinking define MPR's approach—not vendor procedures or corporate mandates. You'll work alongside bright, motivated engineers and project managers across mechanical, civil, electrical, chemical, and materials disciplines. Questioning attitudes and constructive feedback are valued here; technical accuracy matters more than hierarchy. It's a high-performance culture built on trust and respect since 1964.Career Development Establish yourself as a recognized technical authority across nuclear engineering, not just within one reactor concept. You'll maintain technical breadth that keeps you relevant regardless of which technologies succeed commercially while growing as a leader through mentorship, project management, client engagement, and business developmentMPR Associates, Inc. is an equal opportunity and affirmative action employer, who participates in E-Verify. All qualified applicants will receive consideration for employment without regard to race, color, national origin, sex, religion, age, disability, veteran’s status, sexual orientation, gender identity, genetic information or any other classification as required by applicable laws. MPR is a certified Virginia Values Veterans (V3) employer.Job SummaryJob ID: 2026-1490Category: EngineerType: Full-Time