Spent nuclear fuels project characterization data quality objectives strategy

Lawrence, L.A.; Thornton, T.A.; Redus, Kenneth

doi:10.2172/10114576

Cited by 9 publications

(15 citation statements)

References 2 publications

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“…Past characterization campaigns for both fuel and sludge from K Basins have been governed by formal DQOs (e.g., Makenas 1998Makenas , 1999Makenas , and 2000. Methodology in the K Basin Project DQO Strategy Document (Lawrence 1994), used to select objectives for the present testing, is based on EPA guidance (EPA 1994) but modified for a project, such as K Basin Closure (KBC), seeking to determine bounding conditions to pick design, transportation, and mitigation alternatives. Therefore, the issues were limited to those raised by the independent review panel (Heywood 2006) pertaining to the oxidation process.…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal Testing of K Basin Sludge and N Reactor Fuel at Sludge Treatment Project Operating Conditions

Delegard¹,

Schmidt²,

Thornton³

2007

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Executive SummaryFive bench-scale tests (~50 ml each) were conducted in sealed, un-agitated reaction vessels using sludge samples collected from the K East Basin and particles/coupons of irradiated N Reactor fuel (also from the K Basins). These tests were designed to evaluate and understand the chemical changes that may be occurring under the hydrothermal conditions (e.g., 7 to 72 h at 185°C) of the Sludge Treatment Project (STP) corrosion process and the effects that any changes would have on sludge rheological properties. The two sludge formulations used in these tests were selected to represent nominal (vs. bounding) compositions of the two major sludge feed streams to the STP process. The scoping tests were not designed to evaluate engineering aspects of the process.The hydrothermal treatment affected the chemical and physical properties of the sludge. In each test, significant uranium compound phase changes were identified, resulting from dehydration and chemical oxidation and reduction reactions. Physical properties of the sludge were significantly altered from their initial, as-settled, sludge values including, shear strength, settled density, weight percent water, and gas retention.The high uranium content sludge (~70 wt% uranium) set up to form a very stiff solid that exhibited very high shear strength (120,000 to 170,000 Pa) after hydrothermal treatment at 185°C for 7 to 10 hours under static (unstirred) conditions. Shear strengths of untreated sludge range from about 270 to 8100 Pa. Also, the hydrothermal treatment reduced the water content in the settled sludge by about 20 wt%. The treated sludge was difficult to remove from the Teflon test vessels, with sludge firmly adhering to the Teflon vessel surfaces. The strength of the treated sludge was further evaluated by agitation in water. In a 600-ml beaker, with 400 ml water at ~30°C, the diameters of agglomerates were reduced by about 40 to 50% after 1 hour of agitation with a 5.08-cm (2-in.) diameter impeller rotated at a tip speed of 80 cm/s.Further static tests with lower uranium-content sludges (~16 wt% uranium) run 72 h at 185°C produced softer solids with 9,000 to 16,000 Pa shear strengths. While some sludge adhered to the Teflon liner, it was not tenaciously bound. The agglomerates from these tests were relatively weak and, in some cases, were disintegrated with a gentle stream of water. The water content in the settled sludge was not significantly affected by the hydrothermal treatment.Chemical phase alteration, observed by X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry, gave evidence that solids dissolution followed by precipitation was responsible for the increased strengths of the sludge products. The presence of organic ion exchange resin (OIER) and polymer flocculent (constituents known to be in K Basin sludge) in the lower uranium-content sludge did not appear to have a significant impact on the physical behavior of the post-treated sludge.Four irradiated uranium metal fuel coupons were included in on...

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Section: Introductionmentioning

confidence: 99%

Hydrothermal Testing of K Basin Sludge and N Reactor Fuel at Sludge Treatment Project Operating Conditions

Delegard¹,

Schmidt²,

Thornton³

2007

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“…Detailed characterization plans will be structured using the Data Quality Objective (DQO) process to support Path Forward project decisions (Lawrence et al 1994). …”

Section: Scopementioning

confidence: 99%

“…All SNF Project characterization sampling campaigns will be planned using the modified DQO process called out in SNF Project Characterization Data Quality Objectives Strategy (Lawrence et al 1994). The results of the DQO process will be documented, issued, and controlled as an…”

Section: Hnf-sd-snf-pln-010 Revmentioning

confidence: 99%

“…The SNF Project is fully committed to utilizing the DQO approach to define characterization needs (Lawrence et al 1994). The DQO process will govern the development of the individual Sampling and Analysis Plans (SAPS), examination strategy documents, test plans and instructions prepared for each series or group of examinations or measurements.…”

Section: Snf Project Supporting Document In Accordance With Requiremementioning

confidence: 99%

“…The responsible Lead Engineer will plan each SNF and sludge sampling campaign using the DQO process described in the Characterization Data Quality Objectives Strategy document (Lawrence et al 1994). Upon completion of the first six steps of the process, the Lead Engineer should be able to define the following information: List of the objectives or problems (decisions) that the sampling campaign must address Identify the problem resolution strategy for each of the listed objectives Define the technical information that must be collected or known in order for the objectives to be achieved Identify the logic (decision rule) that will be used to resolve the objectives with the information collected Identify the accuracy, precision, and representativeness (decision error) required of the results in order to make correct decisions…”

Section: Planning Scientific Investigationsmentioning

confidence: 99%

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