Preconceptual Study of the Direct Feed High-Level Waste Concept

Company Performed Work:

AEM Consulting, LLC

Work Description:

The scope of work required preparation of a preconceptual engineering study for implementing the Direct Feed High Level Waste (DF HLW) concept proposed by WRPS as a strategic initiative.  The DF HLW concept is based providing the capability to feed from the Hanford Double Shell Tanks directly to the WTP HLW Vitrification Facility, by-passing the WTP Pretreatment Facility.  The DF HLW concept is proposed as an approach to gain early beneficial use of the HLW Vitrification Facility and mitigate potential delays in the Pretreatment Facility startup date.

A three (3) phase approach was proposed for the DF HLW concept, with each phase building on equipment installed by a previous phase.  Phase 1 is a hot startup configuration emphasizing minimal incremental equipment requirements to allow initial HLW glass production to occur at a reduced rate for an interim time period (nominal 0.5 canisters/day).  Phase 2 provides additional equipment to allow glass production at an increased rate and demonstrate the HLW Vitrification Facility throughput (nominal 2 canister/day).  Phase 1 and 2 concepts are based on providing the DF HLW capability for an interim time period and relies on activities in tank farms for any pretreatment of waste solids prior to being transferred to the HLW Vitrification Facility feed tanks.  Secondary liquid wastes generated by the vitrification facility off-gas system and are returned to the tank farms during Phase 1 and 2.  Phase 3 provides additional equipment to support the DF HLW capability throughout the balance of mission, complementing operation of the Pretreatment Facility.  The additional equipment is included to allow solids washing, caustic leaching, oxidative leaching, and slurry solids concentration adjustment for vitrification feeds without relying on activities in the tank farms.  Phase 3 is applicable after Pretreatment Facility startup and relies on the facility for processing secondary liquid waste generated by the HLW Vitrification Facility and DF HLW systems.

The scope of work included preparation of a process description for each phase of the initiative concept within context of the existing HLW vitrification process, including:

  • material balances to describe material flows;
  • time-cycle analysis based on the material balance to support sizing of vessels;
  • sizing of facility structures required to house the process equipment;
  • system implementation description, including integration with WTP operating phases;
  • presentation of capital and operating cost and implementation schedule estimates; and
  • identification of risk, safety and regulatory considerations, issues and uncertainties, and implementation impacts.
  • Tasks include:
  1. Prepare a functional breakdown of the DF HLW concept, with associated requirements, to define the basis for selecting unit operations included in each operating phase;
  2. Develop introductory material and a description of the baseline HLW Vitrification Facility operation;
  3. Develop narrative of the integration of the DF HLW concept with WTP flowsheets, structures, processes, schedules, and objectives;
  1. Consult with VSL to select relevant feed material for study basis;
  2. Prepare material balances for each phase and integrate time-cycle analysis within the context of the WTP;
  3. Estimate facility hazard category and maximum equipment dose rate;
  4. Develop a narrative description DF HLW facilities, systems, and process equipment, including a layout supporting each process phase;
  5. Develop a narrative description emphasizing WTP supporting systems and interfaces;
  6. Provide WRPS operating staff and consumable material estimates based on the process and facility descriptions;
  7. Develop concise capital and operating cost and schedule estimates for the implementation of each phase from input returned from WRPS;
  8. Develop tables and narrative summarizing risks identified during preparation of the DFHLW preconceptual engineering study.
  9. Document all calculations and required assumptions for each task; and

Start / End Date:

April 2012 through September 2012

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