Support on Accident Chemistry for UK HPR1000

The purposes of this contract are to provide ONR with independent advice on the safety significance of relevant accident chemistry effects, which are applicable to the UK HPR1000 design. This should include consideration of the latest standards, guidance and relevant good practice regarding the accident chemistry of pressurised water reactors (PWRs). Furthermore, the contractor will need to provide on-going expert advice and support to ONR in its assessment of the accident chemistry aspects of the UK HPR1000 generic design and safety case during Step 3 of GDA. During Step 3 of GDA, the main focus of this work will be fission product behaviour and mitigation, LOCA and SG Tube Rupture, however, it is understood that this will include, by necessity, some reference to the other chemistry-relevant aspects considered below. The contractor is required to identify, evaluate and collate the latest available guidance, standards and relevant good practice (RGP), as applicable to the accident chemistry of PWRs. ONR commissioned similar studies during the GDAs of UK EPR™ and AP1000®. They should be considered as the baseline for this activity. The TSC is expected to take that work as one of the inputs and together with their own skills, knowledge, experience and resources etc., focus on providing either brief confirmatory statements regarding the current applicability of that already established baseline, or explain any gaps between the latest approaches in PWR accident chemistry and the baseline, including commentary on their likely overall significance, as appropriate.