Sanders Engineering Consultants

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Charlotta Sanders is a senior nuclear engineer with more than 25 years of experience spanning commercial nuclear power, national laboratories, international organizations, and advanced academic research. As the owner of Sanders Engineering and a licensed Professional Nuclear Engineer in Nevada and Idaho, she provides deep technical expertise in reactor physics, radiation protection and shielding, nuclear criticality safety, nuclear waste management, probabilistic risk assessment, and Monte Carlo methods. Her career includes nearly a decade of safety and design leadership for the U.S. geological repository program at Yucca Mountain, extensive consulting support to utilities, fuel cycle facilities, and federal agencies, and international engagement through the World Nuclear Association and the International Atomic Energy Agency. 

Charlotta has authored more than 50 technical publications, including multiple U.S. NUREGs, and co‑authored the Elsevier book Nuclear Waste Management Strategies – An International Perspective. In parallel with her consulting practice, she serves as a part‑time Associate Research Professor at the University of Nevada, Las Vegas, where she teaches graduate‑level courses in criticality safety, reactor physics, radiation protection, PRA, and Monte Carlo methods, and leads research on spent fuel behavior and advanced fuel cycle modeling. Her work is distinguished by rigorous technical analysis, regulatory fluency, and a long record of supporting safe, practical, and innovative nuclear solutions.

Arzu Alpan is a senior nuclear engineer with more than twenty‑two years of experience spanning commercial nuclear power, national laboratory research, and international standards development, with deep expertise in radiation transport, shielding, reactor dosimetry, and aging management of reactor materials. Her career includes over fourteen years at Westinghouse Electric Company—where she led deterministic radiation transport analyses, fluence evaluations supporting aging effects on reactor materials, cross‑section library development, and shielding design—and more than eight years at Oak Ridge National Laboratory, where she served as Group Leader for the Nuclear Transmutation and Decay Physics Group, Chair of the Nuclear Energy and Fuel Cycle Division Software Quality Assurance Board, and Lead for the Shielding Leadership Initiative.

Arzu has been principal investigator for multiple U.S. Nuclear Regulatory Commission programs, including SCALE 6.3 shielding validation and extended‑enrichment/high‑burnup spent fuel analysis, and has contributed extensively to radiation evaluation methodologies for concrete biological shield and reactor pressure vessel extended beltline regions for nuclear power plant life‑extension. A long‑standing leader in the American Nuclear Society and a project leader and expert member within ISO and ANSI/ANS standards committees, she has shaped national and international guidance on neutron and gamma‑ray cross sections, shielding methods, and reactor physics. Dr. Alpan’s work is distinguished by rigorous technical depth, multidisciplinary leadership, and a sustained record of advancing radiation transport science and nuclear safety.

  Fakhrul Islam is a nuclear engineer with seven years of hands‑on experience in advanced reactor core design, reactor physics modeling, multiphysics simulation, and safety analysis across commercial, startup, and national laboratory environments. His work spans core design and safety‑basis restoration for the Palisades restart, reload thermal‑hydraulic analysis at Framatome, and first‑principles neutronics and multiphysics development for Valar Atomics’ prototype microreactor. Dr. Islam has executed coupled neutronics‑thermal‑hydraulics evaluations, startup and power‑ascension physics testing support, and licensing‑basis analyses aligned with NRC General Design Criteria and DOE‑STD safety frameworks. His technical portfolio includes extensive experience with SCALE/TRITON, OpenMC, STAR‑CCM+, MOOSE, GOTHIC, MCNP, and high‑performance computing environments, as well as development of safety cases, PIRTs, and conceptual design safety reports for next‑generation reactor systems. He has authored federal funding proposals ranging from early‑stage R&D to $300M‑class programs, taught university‑level nuclear engineering, and contributed to verification and validation of ORNL’s advanced radiation transport tools. Dr. Islam holds a Ph.D. in Nuclear Engineering focused on microreactor design and safety analysis and is co‑inventor of a patented compact mobile reactor system, bringing a modern, innovation‑driven perspective to reactor design and nuclear safety challenges. 

Charles Robinson is a senior Nuclear Criticality Safety Engineer with more than thirty years of experience supporting NRC‑licensed and DOE‑contracted nuclear processing facilities, specializing in criticality safety evaluations, chemical and process safety analysis, integrated safety assessments, and operational readiness. His career spans the U.S. Nuclear Regulatory Commission, BWX Technologies, DOE sites, national laboratories, and major enrichment and decommissioning projects, where he has performed and independently reviewed NCSEs, led hazards analyses, conducted inspections and investigations, and supported operational restarts for high‑consequence nuclear and chemical systems. Charles has deep expertise in Monte Carlo methods (SCALE/KENO), accident scenario development, IROFS evaluation, and the design of safety controls for complex nuclear processes. At Sanders Engineering, he provides specialized consulting to Urenco USA’s LEU+ enrichment expansion, developing regulatory‑quality analyses and serving as a subject matter expert in both criticality and chemical process safety. His earlier roles include serving as DOE’s departmental representative to the Defense Nuclear Facilities Safety Board, supporting LANL’s plutonium facility restart, and conducting safety analyses across multiple commercial and government nuclear sites. A licensed Professional Engineer and long‑standing member of ANS, AIChE, and ACS, Charles brings a rigorous, practical, and highly experienced perspective to nuclear safety challenges.

Josh Ordoñez is a nuclear engineer specializing in nuclear criticality safety and nuclear safety for NRC- and DOE-regulated facilities. His experience is focused around the preparation of NQA-1 deliverables in both an operations support capacity for existing production facilities and a design engineering capacity for new facility license applications.

At Westinghouse Electric Company, Josh performed spent fuel pool NCS calculations and sensitivity studies used in LARs for clientele transitioning to newly designed ATFs. At Urenco USA, he supported LEU enrichment operations by performing 70.72 evaluations, NCS analyses, configuration management reviews, hazard and accident analyses, SER-directed actions, and duties as acting ISA/NCS manager. At Los Alamos National Laboratory, Josh was a part of the defense production mission and prepared DOE-STD-3007 NCS evaluations of Pu/HEU fissionable material operations. At Bechtel Power Corporation, he contributed to the SAR of the Natrium advanced reactor project where he wrote atmospheric dispersion/dose consequence calculations and authored the Kemmerer Unit 1 radioactive waste management program.

Along with earning a B.S. in Nuclear Engineering from Texas A&M University, Josh has built his technical foundation through industry-recognized training programs such as the DOE NCSP and the ABS PHA Safety program. Throughout his career, he has applied regulator-aligned methods of simulating radiological and chemical consequence scenarios through modeling software such as MCNP, SCALE/KENO, MONK, RASCAL, and GASPAR II. Josh brings a strong understanding of the regulatory frameworks surrounding 10CFR50, 10CFR70, and 10CFR830 along with a demonstrated capability in developing technically-defensible and customer-focused solutions for unique nuclear engineering problems.

 Greg Tidd is a senior nuclear safety engineer with more than thirty years of experience across DOE 10 CFR 830 facilities, NRC 10 CFR 70 fuel‑cycle operations, and commercial nuclear power under 10 CFR 50, bringing unmatched depth in safety basis development, accident analysis, hazard evaluation, and regulatory compliance. His career spans major DOE sites—including Hanford, Savannah River, Pantex, Rocky Flats, Fernald, and INL—where he has prepared and reviewed DSAs, TSRs, USQ determinations, 70.72 evaluations, and Integrated Safety Analyses, serving as team lead, subject matter expert, and peer reviewer for high‑consequence nuclear operations. Greg has authored numerous NQA‑1‑compliant accident analyses, dispersion models, source term evaluations, fire and seismic consequence assessments, and probabilistic risk assessments, with technical capability covering RASCAL, ARCON96, CFAST, CAFTA, MicroShield, and a broad suite of engineering and modeling tools. His background includes leadership roles in nuclear logistics, system engineering, seismic qualification, and design engineering, as well as extensive experience resolving DNFSB issues, supporting operational readiness, and modernizing safety basis programs. With a foundation in physics from the U.S. Military Academy at West Point and decades of hands‑on work across the DOE complex and commercial nuclear sector, Greg brings rigorous analytical skill, deep regulatory fluency, and a proven record of delivering defensible, safety‑critical engineering solutions.