Provision of a technical seminar on safety analysis of high temperature gas-cooled reactor technology

ONR is seeking to engage one of the Technical Support Contractors (TSC) appointed on Lot 1 of its Technical Support Framework. The TSC is required to produce a training seminar to reflect ONR's needs. The basis of this training seminar is as per ONR's identified needs outlined below: HTGR fault identification studies/outcomes and general progression of challenging transients considered in HTGR safety analysis; An overview of the key phenomena associated specifically with safety analysis of HTGR technology; Thermal hydraulic behaviour; Core oxidation behaviour; HTGR neutronics and inherent core reactivity response; A summary of the current knowledge level of these phenomena, including identification of key experimental facilities used to validate computer models and any significant areas of uncertainty / knowledge gaps; An overview of available HTGR safety systems and passive features, their design, level of technical maturity and deployment, and performance in fault conditions: Shutdown systems and reactivity control features; Decay heat removal; Containment systems and barriers. Key safety parameters and how they are monitored; Safety Analysis; covering key faults and hazards, accident sequences, acceptance criteria (including fuel limits), status of hazard analysis, available modelling tools / computer codes; for the following key fault sequences, amongst others: Air and water ingress accidents (air ingress to include: chimney effect, dynamic stability and isobaric pumping); Depressurised Loss of Forced Circulation (DLOFC) accidents with failure of decay heat removal system; Double-ended Guillotine Break (DEGB) of hot gas duct; and Anticipated Transient Without SCRAM (ATWS). An overview of how key Structures, Systems and Components (SSCs) are protected against direct and indirect effects (internal hazards) in light of the above Source terms in normal operations (coolant and dust activity) and accident conditions Graphite dust behaviour, including: generation; distribution and settling; clean-up options, including helium purification system; and mobility in transients. TRISO fuel behaviour in accident conditions, including: experiments and OPEX; failure mechanisms; core degradation during a major depressurisation fault with air ingress; radionuclides bypassing SiC barrier. Case Studies: Example application of computer codes to support safety analysis for a recent HTGR design; Status of deployment; knowledge gaps, research and development activities