Development of A Risk Informed Approach to D&D Priority Setting Forensic Evaluation of D&D at Oak Ridge with a Focus on K 25 and K 27 James H. Clarke Henry Mayer Charles W. Powers
A Risk Informed Approach to Setting Priorities for D&D Investigators: J. H. Clarke (lead), C. W. Powers, H. Mayer, D. S. Kosson Project Objective: The purpose of this task is to provide strategic assistance to the Department of Energy regarding understanding and providing a risk-informed template to evaluate the mission trade-offs associated with accelerating vs. delaying specific D&D projects - and D&D generically. The goal is an approach that enables comparative evaluation of D&D priority or D&D in combination with, for example, soil & GW challenges. Relevance and Impact to DOE: D&D is an essential element of the DOE-EM mission in terms of mission completion, asset revitalization and life-cycle cost. Significant investment has been made in D&D at specific sites particularly using dedicated UE and ARRA funds and both are running out of resources. Still, often D&D is deferred without clear recognition of the potential for increased risks and costs due to delay. Additionally, opportunities for improved safety and reduced costs are not clear. And often the role of D&D in either enabling or prohibiting implementation of other EM works is poorly understood. Clarification of these issues through the thorough and independent testing of the hypothesis that better characterization to provide data analogous to other EM activities will best clarify when to give specific D&D projects priority in an environment where risk-informed decision making is likely to increase in importance. Accomplishments: Gained willingness of diverse site & contractor personnel to interact and explain the (quite different) bases for how they prioritize D&D at their sites and involve regulators in the priority-setting and project implementation process Early Accomplishments: Presentations to the American Nuclear Society-September 2010 and October 2011-well received as the project began to focus more specifically on a template for better prioritizing D&D projects White paper now a matter of intense discussion with EM particularly as to whether the focus should be generic or 2 on improved characterization and specific projects.
Overview EM continues to pursue its cleanup objectives within the overall framework of achieving the greatest risk reduction benefit per radioactive content (wastes that contain the highest concentrations of radionuclides) overlaying regulatory compliance commitments and best business practices to maximize cleanup progress. To support this approach, EM has prioritized its cleanup activities: Activities to maintain a safe, secure, and compliant posture in the EM complex Radioactive tank waste stabilization, treatment, and disposal Spent (used) nuclear fuel storage, receipt, and disposition Special nuclear material consolidation, stabilization, and disposition High risk soil and groundwater remediation Transuranic and mixed/low level waste disposition Soil and groundwater remediation Excess facilities deactivation and decommissioning Source: 2012 DOE EM Congressional Budget Request, emphasis added
Three Major Factors Do or Should Drive D&D Prioritization Cost Risk Exogenous Factors* * Factors entering or originating from outside the D&D system or project
Observations D&D activities get funded and implemented when an exogenous factor propels D&D work into the forefront. Exogenous factors tend to be episodic and relatively short lived; as a result, D&D work is not a coherent, cost effective and risk informed program of EM activity. Absent a more complete algorithm for D&D program planning and advocacy the future D&D processes will not be significantly different. Risk informed remediation decision making involves evaluations of various remedial alternatives focused primarily on what is the best approach. Risk informed D&D decision making, in many respects, is more complicated because the focus is on both what (e.g., safe storage vs. demolition vs. entombment and various combinations) and also on when (now vs. later vs. never). As a result of categorizing D&D projects as non time critical removals the RI/FS or other kinds of environmental assessments are essentially bypassed. Consequently, much of the information needed to make a risk informed comparison with other types of projects e.g., soil and ground water remediation, and waste management, is not available.
An example: Co ordination D&D with Groundwater Cleanup to Achieve Area wide Closures at Savannah River the P Area Risk Footprint Reduction goals linked to Availability of ARRA Funds Exogenous Factors Integrated Cost
ETTP and K 25/K27 D&D Oak Ridge Gaseous Diffusion Plants to produce enriched Uranium built at Oak Ridge (1944), Paducah (1951) & Portsmouth (1952) ETTP = total ORGDP (640 acres, 340 buildings) K 25 and K 27 primary GDPs at ETTP K 25 and K 27 closed and placed in standby mode 1964; placed in shutdown status 1987 K 25 D&D started 2003; ETTP cleanup to be completed by 2008 (BJ contract, ETTP 2002)
K 25/K 27 D&D Estimated Cost at Completion Millions of Dollars $1,600 $1,400 BJ Estimate + OR EM 2012 Worksheet $1,200 $1,000 $800 BJ 2007 Re Baseline $600 BJ 2004 Worksheet $400 $200 $0 2003 2004 2005 2006 2007 2008 2009 2010 2011
K 25: Largest D&D to Date 1 mile long; 40 acre footprint; U shaped building on four levels; built in 18 months 60 years old when D&D began in 2003; unused for almost 40 years 54 Units containing heavy process equipment and contaminated with U 238, weapons grade U 235, U 234 and UF 6, Tc 99, mercury, PCBs & asbestos Physical deterioration worker accident 2006 D&D completion expected 2014 (11 yrs) at cost exceeding $1 billion (3 times K25/K27 estimate)
K 25: What Happened? BJ and DOE 2003 contract based on top down cost target; rising costs hidden by moving dollars within total contract, and K 25/K 27 aggregate Structural deterioration and 2006 employee accident caused major investment in safety equipment and reduced use of humans Insufficient characterization; Reduced funding; Criticality Incredible; Increased unit buffers; Constant resequencing; 2007 separation from K 27; Weak project management
K 27: A Repeat??? Constructed 1945, similar in structure to K 25; 9 acre footprint; total 1.1 sq.ft. floor area on 4 levels Closed 40 yrs; contains same processing equipment and contaminates as K 25 (lower enriched U235, but still criticality capable) Roof in poor condition; Rainwater entering building through roof holes spreading contamination Poured concrete versus pre cast floors that failed in K 25, but water causing severe spalling reducing load capacity Estimate more than 50% of roof could fall on operating floor within 5 years D&D to start 2014, completed in 2 yrs at $300 million cost
Summary Observations and Recommendations Deferral of D&D can have significant negative consequences with respect to Increasing safety issues and cost (K 25 and K 27 at OR). In order for D&D projects to compete on a level playing field additional information comparable to that generated in an RI investigation is needed. The persistent inability to accurately and therefore credibly estimate the cost of large projects saps the will to initiate large D&D projects. In many cases, D&D should be linked to soil and groundwater so that an integrated assessment can be performed. The current approach to defining performance metrics for D&D is not risk informed. A score is obtained only when the project achieves its designated end state. Credit should be given when risk reduction measures are taken, e.g., removal of hazardous internals.