Steve Additon brings more than forty-five years of experience in ensuring nuclear safety for Department of Energy (DOE) facilities, combining engineering insight with a sound understanding of nuclear safety fundamentals and requirements. He has served as a senior technical advisor and as a technical and program manager.
Since 1995, Mr. Additon’s focus has been on safety basis development and implementation, including Technical Safety Requirements (TSRs) and the related Unreviewed Safety Question (USQ) process at Rocky Flats, Idaho Cleanup Project, and Hanford Plateau Remediation. Also while at Hanford, he supported the DOE Office of River Protection by preparing complex Safety Evaluation Reports (SERs) for the Waste Treatment Project. While at Rocky Flats, he led the contractor efforts to resolve Defense Nuclear Facility Safety Board (DNFSB) issue 94-3 involving the seismic capability of Building 371 for its proposed plutonium storage mission. Earlier in his career, he led the DOE-sponsored Advanced Reactor Severe Accident Program supporting vendors and the Electric Power Research Institute in the application of severe accident insights from liquid metal design programs and sponsoring new research to support robust passive designs. He led root cause evaluation and collective significance determinations for construction quality issues affecting startup of Comanche Peak. Mr. Additon began his career as a system engineer and plant modeling analyst; he grew to lead the natural circulation design of the Fast Flux Test Facility, and performed the technical evaluation of the implications of the TMI accident for this diverse design.
Mr. Additon holds a B.S. in Mathematics and an M.S. in Nuclear Engineering from Carnegie-Mellon University, and an MBA from the University of Washington; he has had both L- and Q-clearances.
Mr. Additon consistently demonstrates quick comprehension of the keys to project success. At Hanford, he developed the new TSRs needed to support packaging and drying of the last remaining fuel material at the K-West Basin, made key contributions to the strategic plan for subsequent sludge removal, and led the safety basis team at the K-area cleanup site, providing necessary guidance to enhance performance. His Waste Treatment Plant SERs conveyed the bases for the approvals being granted and the known limitations to be addressed as the design progressed. At Idaho, he developed a a new safety compliance strategy that permitted the Radioactive Waste Management Complex to resume suspended waste retrieval and disposal; his implementing safety basis supported the successful operation of a succession of retrieval facilities meeting the waste removal objectives established with the State of Idaho.
At Rocky Flats, he maintained the evolving safety basis for Building 371 as D&D progressed to demolition, preparing hundreds of USQs and numerous safety basis updates in the process. The DNFSB accepted the resolution strategy for issue 94-3 that focused on practical upgrades rather than new design criteria judged inappropriate for an existing facility. Prior to that, he supported DOE-HQ on seismic policy drafting the report that set the stage for national consensus standards to replace the 1020 series; he was an author of ANSI/ANS 2.26 – the American National Standards Institute/American Nuclear Society Standard 2.26 – Categorization of Nuclear Facility Structures, Systems, and Components for Seismic Design. The Advanced Reactor Severe Accident Program sponsored unique experiments demonstrating the potential for cooling relocated core material on a vessel lower head as one part of its broader effort to support the development of severe accident design requirements appropriate for robust “passive” designs. Startup testing demonstrating that the Fast Flux Test Facility natural circulation capability was consistent with his design predictions.
Overall, Mr. Additon has sought and succeeded in challenging assignments that invited application of his technical, strategic, and oral and written communication skills. Mr. Additon has focused on ensuring safety and regulatory compliance with an eye to more practical approaches consistent with the facility mission.