Technical Justification and Choice for Remediation Methods

When out of normal material or very high activity is encountered in a Deactivation & Decommissioning (D&D) project, special considerations are needed. As the source term increases, the level of attention to planning, project cost and risk management must increase as well. WorleyParsons (WP) is engaged in identifying, screening and documenting (with follow on project design expected) the various remediation methods available to remove highly contaminated soils discovered under a hot cell. Soil dose rates have been measured in the 70 to 100 Sieverts/hour range, with radionuclide mix to be defined in mid to late summer 2011 from samples collected in June 2011. The scope of this project is to identify remedial techniques and removal methods (means and methods) and develop a set of technically implementable remedial alternatives (alternatives). These remedial alternatives will be screened by a Technical Panel consisting of WP and client experts using a WP defined screening process to narrow the list of alternatives. Transparency and un-biased choice of actions is key to owner and public confidence in the process and the choice of the ultimate path forward. The poster will show Phase 1 — how potential remedial techniques and removal methods (means and methods) were first identified, catalogued and initial screened. Following the initial screening, the remaining means and methods are combined to form an alternative — a stabilization means with a removal method are matched with a waste container to from an alternative. A rough order of magnitude (ROM) cost estimate and high level schedule are also developed for each alternative. In parallel with the above, screening criteria with associated design attributes were identified and given a weight factor and attribute value, which are then multiplied together and used to develop a decision matrix for the developed alternatives. Two parallel processes — screening criteria development and alternative development — are being pursued to allow better focus on each while not prejudicing the final alternative selection. Phase 2 actions — the expert panel - grade each alternative against the pre-approved screening criteria using the decision matrix that compiles results — real time but blind to the panel. The top two to four scores from this last effort will proceed to a pre-conceptual, conceptual design phase and the expert panel reconvened to make the final decision on the remediation methods to be used for removing the soil / contamination.