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

0977-6Version 15 Model ParametersThe specification of spatially variable parameters for the additional vaults andparameters for each human intrusion and occupancy event is presented in this section.5.1 Spatially Variable Parameters5.1.1 Radionuclide InventoryThe radionuclide inventories for predicted disposals to Vaults 15 to 20 have beenprovided in two spreadsheets (Case A: PIER V_2_3_a 19 11 10 ART AH.xls and CaseB: PIER V_2_3_b 19 11 10 ART AH.xls). These cases represent two differentinventory cases as described by Paulley (2011):• Case A considers wastes currently identified in WIDRAM 09 as destined forLLWR, “LLWR 2” or the planned geological disposal facility. This additionalinventory does not include waste streams currently anticipated to be disposedof at Dounreay or other identified sites, but could amount to an additionalpackaged waste volume of 573,000 m 3 . A large fraction of this additionalvolume is from Stage 3 reactor decommissioning.• Case B considers, in addition, the disposal of solid LLW associated with ‘newbuild’ construction, operation and decommissioning. The identified inventoryis speculative and probably a cautious overestimate, but acts as a baseline foranalyses, and suggests an additional packaged waste volume of 730,000 m 3 .The radionuclide activities for each inventory case have been mapped to the modelgrid cells as indicated in Figure 3.1, and in Table A.2 (Case A) and Table A.3 (CaseB). Note that package stacking heights vary across the vaults to take account of spaceprovided by the cap profiling (see below).For the human intrusion assessment, the radionuclide activities for a vault have beenassumed to represent activities at the time of completion of disposals to that vault (i.e.radioactive decay to this time has been ignored). The vault filling completion dates,from which time decay has been assumed to begin, are as shown for each case inTable 5.1.Galson Sciences Ltd 13 21 March 2011