Waste Treatment and Immobilization Plant (WTP) and Direct Feed Low-Activity Waste Strategic Planning
The WTP is a first-of-a-kind project of immense scale and complexity. It will eliminate the environmental threat posed by 56 million gallons of nuclear waste currently stored at the Hanford Site. The 56 million gallons of waste are a byproduct of national defense plutonium-production efforts during World War II and the Cold War era. The waste resides in 177 aging underground tanks. Of these, more than 60 have leaked, contaminating the subsurface and threatening the Columbia River.
The WTP will use vitrification technology to stabilize the waste. Vitrification involves blending the waste with glass-forming materials and heating it to 2,100 degrees Fahrenheit (1,149 degrees Celsius). The molten mixture is poured into stainless steel canisters to cool and solidify. In this glass form, the waste is stable and impervious to the environment, and its radioactivity will safely dissipate over hundreds to thousands of years. The Low-Activity Waste (LAW) treated to meet regulatory requirements will be disposed of at the Interim Disposal Facility (IDF) on the Hanford Site. The High-Level Waste (HLW) containing long-lived radioisotopes will be stored on the Hanford Site pending final disposal decisions.
The WTP is the largest and most complex nuclear facility to be built in the U.S. in decades. The construction site spans 65 acres and includes four major nuclear facilities – Pretreatment, Low-Activity Waste (LAW) Vitrification, High-Level Waste (HLW) Vitrification and the Analytical Laboratory (Lab).
Currently, the WTP is being configured and commissioned to enable Direct Feed Low Activity Waste (DFLAW) processing while engineering, procurement, and construction of the Pretreatment and HLW facilities is completed.
Process Design and Improvement
An early WTP facilities review by an expert Enhanced Flowsheet Review Team (EFRT) identified several process risks associated with mixing, line plugging and pretreatment processes that required resolution to improve the operability and throughput performance of the WTP. Polestar led the oversight and coordination of a process throughput improvement team to conduct formal studies to address process capacity issues identified by the EFRT. Polestars efforts in collaboration with others resulted in projected throughput increases of twice the original design capacity and provided a path forward framework for other design and process improvements to reduce the risks to throughput and overall plant availability. In addition Polestar was selected to participate on a team of experts to evaluate and resolve persistent deficiencies in the flow-down of technical requirements from the project’s top-level documents to the implementing documents which resulted in hardware requirement traceability and inspection issues. Polestars efforts in collaboration with others on the team identified over 900 potential issues of varying potential impact that once resolved by the project significantly improved the confidence of equipment design and procurement.
Facilities Design and Operability
Polestar was selected to participate as process engineering, operations and maintenance experts to support a DOE sponsored design and operability review team for the Waste Treatment Plant (WTP) Low Activity Waste (LAW) and High-Level Waste (HLW) treatment facilities. The intent of the design and operability reviews was to provide DOE increased confidence in the design and operability of the LAW and HLW facilities for key mechanical and process systems. Completion of the HLW review was also a prerequisite to resumption of design and construction activities for the HLW facility. Polestar prepared the review plan that described the review approach, led the process and mechanical systems teams, participated on the HVAC team, prepared briefings for senior ORP and DOE-HQ management and prepared final review reports. Polestar also was the lead assessor for verifying underlying causes for many of the vulnerabilities for the HLW facility were adequately resolved. This included performing a series of surveillances for closure of programmatic issues for inadequate design execution and control, inadequate control system design, transfer of scope and risk to the commissioning phase, and inadequate consideration of maintenance and waste management requirements. The result of this work was considered by DOE to be a key element to the successful completion of the WTP project.
Project Performance Assessment
Polestar experts were selected to assist the ORP WTP Performance Assurance group for accomplishing oversight for completion of the WTP Project in accordance with multi-year integrated assessment plans. One of the plans verified the WTP effectively implemented extensive recovery efforts and corrective actions for addressing Quality Assurance and Design Control Management issues. The second oversight plan verified engineering, procurement, and construction completion for safety related systems for the Direct-Feed Low Activity Waste (DFLAW) facilities. In conjunction, Polestar provided technical expertise to support the ORP Senior Technical Authority for the WTP to develop strategies, evaluations and plans to ensure outstanding technical issues were fully evaluated and closed to support further WTP process design efforts. Polestar provided technical expertise to the ORP Nuclear Safety Division for expedited development and conditional approval of the LAW facility documented safety analysis and technical safety requirements documents. The support and expertise provided by Polestar has resulted in confirmation that the outstanding quality assurance and design control management issues were addressed, WTP technical issues were adequately closed, and DFLAW systems were completed to support commissioning and readiness activities.
DFLAW Mission Integration, Commissioning and Operational Readiness
Polestar was selected to participate on an inter-organizational technical proposal team tasked with identifying the optimum approach to startup, commissioning and turnover of the WTP facilities for operations which was a predecessor to the current Direct Feed Low-Activity Waste (DFLAW) technical approach and the Mission Integration organization. As a result, Polestar prepared and is currently supporting implementation of an integrated strategy to support the transition of the WTP in the DFLAW configuration to the operations phase. The strategy includes assessing the operational risks associated with spare parts and consumables, procurement of long-lead and high-risk items for the operational phase and coordination of operations phase optimization studies. Polestar is currently supporting procurement of a spare LAW melter and associated cooling panels, refractory and agitation bubblers. Optimization studies defined and coordinated by Polestar have identified a potential of over $500 million in potential savings.