SRNS—Nuclear Safety and Criticality Safety Technical Support Services

Sigma Science provided nuclear safety and criticality safety subject matter experts (SMEs) and engineers to the Savannah River Nuclear Solutions (SRNS) Nuclear and Criticality Safety Engineering (N&CSE) department, supporting the Savannah River Plutonium Processing Facility (SRPPF). Sigma provided these services under a three-year $2.4 million subcontract with Longenecker & Associates, awarded in Aug 2019. The contract scope called for the performance of complex nuclear safety and criticality safety activities to achieve critical decision (CD-1) approval for the SRPPF.

Key activities included:

• Developing preliminary consolidated hazards analysis and a conceptual safety design report.
• Providing technical assistance in developing nuclear safety documents, analyses, and related technical support documentation.
• Developing preliminary nuclear criticality safety evaluations, criticality parameter studies, and criticality parameter sensitivity studies.
• Ensuring nuclear safety documents complied with the requirements of 10 CFR 830, “Nuclear Safety Management,” DOE Order 413.3B, “Program and Project Management for the Acquisition of Capital Assets,” DOE Order 420.1C, “Facility Safety,” and DOE-STD-1189-2016, “Integration of Safety into the Design Process.”
• Addressed various DOE-NNSA stakeholder comments and questions regarding nuclear safety deliverables.
• Performed safety analysis and control development for the Surplus Plutonium Disposition (SPD) Project.

Key contract accomplishments include:

• Serving as members of the SRNS nuclear safety team responsible for developing and documenting a comprehensive nuclear hazard analysis for the SRPPF.
• Authoring substantial portions of the SRPPF Conceptual Safety Design Report, including the accident analysis, that was subsequently approved by NNSA.
• Authoring formal analyses and technical reports on flammable gas explosion hazards and plutonium-iron eutectic formation, supporting SRPPF safety basis development.