Baldwin TD and Hicks TW, Assessment Calculations for Human ...

0977-6Version 1allows for the application of project-specific procedures. For the development andapplication of the human intrusion assessment model, the following project-specificprocedures have been applied:• 0977-PSP2 GoldSim Model Verification, which is designed to ensure that theGoldSim implementation of the human intrusion model is appropriatelyverified for use to conduct assessment calculations.• 0977-PSP3 GoldSim Model Parameter Values, which aims to ensure thatparameter values for the human intrusion assessment are appropriatelyjustified, approved and documented.• 0977-PSP4 GoldSim Model Management System, which ensures that modeldevelopments, data sources and details of the model parameters used arerecorded, so that each code run can be repeated and the results reproduced.The procedure also ensures that there is an audit trail of code runs and resultsusage in project deliverables, such as reports and presentations.1.3 Report StructureHicks and Baldwin (2011) provided a review of potential future human intrusionevents, mathematical descriptions of radiological dose pathways for intruders andothers following intrusion, a description of the implementation of the human intrusionassessment model in GoldSim (GoldSim, 2009; 2010), and the results of assessmentcalculations for reference and alternative radioactive waste inventories for thetrenches and vaults up to construction of Vault 14. To avoid repetition, this reportrefers to Hicks and Baldwin (2011) for the detail of work in these areas and onlyreports the developments and model changes implemented to carry out assessmentcalculations for the extended repository (Vaults 15 to 20). The same potential humanintrusion events are assessed for both the reference and the extended repository cases,and the mathematical descriptions for the radiological dose pathways are unchanged.Section 2 of this report identifies the human intrusion cases and exposure pathwaysconsidered in the assessment model. The treatment of spatial variability in the humanintrusion assessment is discussed in Section 3. Section 4 discusses verification of thehuman intrusion model implementation in GoldSim. Section 5 discusses theparameters that relate to waste disposals, facility design and the exposure pathwaymodels; parameter values used in the model are listed in Appendix A. Section 6presents the results of the human intrusion assessment dose calculations and Section 7provides conclusions.Galson Sciences Ltd 3 21 March 2011