An End State Methodology for Identifying Technology Needs for Environmental Management, with an Example from the Hanford Site Tanks (1999) / Chapter Skim
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4 Results of an End State Based Analysis of Technology Development Needs for the Hanford Tanks
4 Results of an End State Based Analysis of Technology Development Needs for the Hanford Tanks
Pages 53-63
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From page 53... ...
As noted above, there are tentative criteria for some of the end states for the Hanford remediation system. However, to thoroughly identify waste remediation process technology needs, the end states must be completely defined and pertinent attributes of the end states must be described in terms that can be related to process steps.
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From page 54... ...
TECHNOLOGY DEVELOPMENT PROGRAM FOR HANFORD TANK WASTES The Site Technology Coordinating Group (STCG) for Hanford, which includes TWRS program representatives, identifies technology development needs for tank remediation.
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From page 55... ...
TECHNOLOGY ASSESSMENT FOR SELECTED FUNCTIONS OF THE SCENARIOS The three example Hanford waste tank remediation scenarios presented in Figure 4 in Chapter 3 were used to select four functions to illustrate the definition of requirements and technology development needs. The four functional process steps selected for further analysis are (see bold outlined boxes in Figure 5)
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From page 57... ...
As a result, a qualitative functional requirement is to sufficiently understand this operation so that these undesirable species are not formed in unacceptable amounts. Enhanced sludge washing has received a great deal of attention at Hanford because of its cost benefits and the avoidance of process complications (McConville, Johnson, and Derby, 1995, Orme, 19951.
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From page 58... ...
Vitrifier Offgas Processing Offgas processing will be required at venous process steps throughout the Hanford baseline scenario, and also In the committee's reference scenario shown in Figure 5. Ofigases from the HEW and LAW vitrifiers present formidable cleanup problems because of the high temperatures and the resultant decomposition and vaporization of a variety of chemicals (International Atomic Energy Agency, 1988~.
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From page 59... ...
In general, condensers and scrubbers are used to remove vaporized and entrained matenals from offgas streams (International Atomic Energy Agency, 1988, p.
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From page 60... ...
Unless changes to the waste are made, the stabilization agents must be compatible with highly alkaline waste, retain radionuclides, prevent tank collapse, and allow stabilized tanks to meet applicable performance criteria. Specific functional requirements have not yet been developed or postulated.
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From page 61... ...
Because of the greater inventory of radioactive toxic materials in the in situ disposal scenario than in the nearly empty tanks of the committee's reference scenario, we expect the functional requirements for the enhanced barrier system to be much more stringent than for the barrier system in the committee's reference scenario. As with stabilization of unretrieved tanks, translating this into specific quantitative functional requirements (e.g., maximum allowable water ingress and radionuclide release rates as a function of fume)
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From page 62... ...
The committee believes that enhanced barriers could contribute significantly to retention of Important mobile radionuclides on site and to making cost effective alternatives to the Hanford baseline flowsheet feasible. Enhanced barriers have been considered for use in the Hanford baseline, but apparently only research and development on the standard Hanford cap has been funded.
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From page 63... ...
In the case of the unique Hanford situation, where only one private sector contractor remains, this approach should be reassessed with a view toward providing incentives for private sector efficiency, improved technology for potential use by the private sector, and maintaining DOE expertise for the purpose of being able to better manage the privatization work and to provide a contingency option in case privatization fails. The committee also notes that technology development to meet the requirements of alternative scenarios is essentially non-existent.
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