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Title: Statistical analysis of the DWPF prototypic sampler

Abstract

The DWPF process will be controlled using assay measurements on samples of feed slurry. These slurries are radioactive, and thus will be sampled remotely. A Hydraguard{trademark} pump-driven sampler system will be used as the remote sampling device. A prototype Hydraguard{trademark} sampler has been studied in a full-scale mock-up of a DWPF process vessel. Two issues were of dominant interest: (1) what accuracy and precision can be provided by such a pump-driven sampler in the face of the slurry rheology; and, if the Hydraguard{trademark} sample accurately represents the slurry in its local area, (2) is the slurry homogeneous enough throughout for it to represent the entire vessel? To determine Hydraguard{trademark} Accuracy, a Grab Sampler of simpler mechanism was used as reference. This (Low) Grab Sampler was located as near to the intake port of the Hydraguard{trademark} as could be arranged. To determine Homogeneity, a second (High) Grab Sampler was located above the first. The data necessary to these determinations comes from the measurement system, so its important variables also affect the results. Thus, the design of the test involved not just Sampling variables, but also some of the Measurement variables as well. However, the main concern was the Sampler and notmore » the Measurement System, so the test design included only such measurement variables as could not be circumvented (Vials, Dissolution Method, and Aliquoting). The test was executed by, or under the direct oversight of, expert technologists. It thus did not explore the many important particulars of ``routine`` plant operations (such as Remote Sample Preparation or Laboratory Shift Operation).« less

Authors:
; ; ;
Publication Date:
Research Org.:
Westinghouse Savannah River Co., Aiken, SC (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10131456
Report Number(s):
WSRC-MS-91-163; CONF-9104256-12
ON: DE92009761
DOE Contract Number:
AC09-89SR18035
Resource Type:
Technical Report
Resource Relation:
Conference: Symposium on nuclear waste management,Cincinnati, OH (United States),28 Apr - 2 May 1991; Other Information: PBD: [1991]
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; 47 OTHER INSTRUMENTATION; RADIOACTIVE WASTES; SAMPLING; SAMPLERS; CALIBRATION; RADIOACTIVE WASTE PROCESSING; SLURRIES; RHEOLOGY; ACCURACY; EXPERIMENT PLANNING; RESEARCH PROGRAMS; COMPARATIVE EVALUATIONS; DISSOLUTION; GAUSSIAN PROCESSES; PARAMETRIC ANALYSIS; STATISTICAL MODELS; STATISTICAL DATA; LABORATORY EQUIPMENT; 052001; 440800; WASTE PROCESSING; MISCELLANEOUS INSTRUMENTATION

Citation Formats

Postles, R.L., Reeve, C.P., Jenkins, W.J., and Bickford, D.F. Statistical analysis of the DWPF prototypic sampler. United States: N. p., 1991. Web. doi:10.2172/10131456.
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Postles, R.L., Reeve, C.P., Jenkins, W.J., & Bickford, D.F. Statistical analysis of the DWPF prototypic sampler. United States. doi:10.2172/10131456.
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Postles, R.L., Reeve, C.P., Jenkins, W.J., and Bickford, D.F. Tue . "Statistical analysis of the DWPF prototypic sampler". United States. doi:10.2172/10131456. https://www.osti.gov/servlets/purl/10131456.
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@article{osti_10131456,
title = {Statistical analysis of the DWPF prototypic sampler},
author = {Postles, R.L. and Reeve, C.P. and Jenkins, W.J. and Bickford, D.F.},
abstractNote = {The DWPF process will be controlled using assay measurements on samples of feed slurry. These slurries are radioactive, and thus will be sampled remotely. A Hydraguard{trademark} pump-driven sampler system will be used as the remote sampling device. A prototype Hydraguard{trademark} sampler has been studied in a full-scale mock-up of a DWPF process vessel. Two issues were of dominant interest: (1) what accuracy and precision can be provided by such a pump-driven sampler in the face of the slurry rheology; and, if the Hydraguard{trademark} sample accurately represents the slurry in its local area, (2) is the slurry homogeneous enough throughout for it to represent the entire vessel? To determine Hydraguard{trademark} Accuracy, a Grab Sampler of simpler mechanism was used as reference. This (Low) Grab Sampler was located as near to the intake port of the Hydraguard{trademark} as could be arranged. To determine Homogeneity, a second (High) Grab Sampler was located above the first. The data necessary to these determinations comes from the measurement system, so its important variables also affect the results. Thus, the design of the test involved not just Sampling variables, but also some of the Measurement variables as well. However, the main concern was the Sampler and not the Measurement System, so the test design included only such measurement variables as could not be circumvented (Vials, Dissolution Method, and Aliquoting). The test was executed by, or under the direct oversight of, expert technologists. It thus did not explore the many important particulars of ``routine`` plant operations (such as Remote Sample Preparation or Laboratory Shift Operation).},
doi = {10.2172/10131456},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Dec 31 00:00:00 EST 1991},
month = {Tue Dec 31 00:00:00 EST 1991}
}
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Technical Report:
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DOI:  10.2172/10131456
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  • ; ; ; ...
    The DWPF process will be controlled using assay measurements on samples of feed slurry. These slurries are radioactive, and thus will be sampled remotely. A Hydraguard{trademark} pump-driven sampler system will be used as the remote sampling device. A prototype Hydraguard{trademark} sampler has been studied in a full-scale mock-up of a DWPF process vessel. Two issues were of dominant interest: (1) what accuracy and precision can be provided by such a pump-driven sampler in the face of the slurry rheology; and, if the Hydraguard{trademark} sample accurately represents the slurry in its local area, (2) is the slurry homogeneous enough throughout formore » it to represent the entire vessel To determine Hydraguard{trademark} Accuracy, a Grab Sampler of simpler mechanism was used as reference. This (Low) Grab Sampler was located as near to the intake port of the Hydraguard{trademark} as could be arranged. To determine Homogeneity, a second (High) Grab Sampler was located above the first. The data necessary to these determinations comes from the measurement system, so its important variables also affect the results. Thus, the design of the test involved not just Sampling variables, but also some of the Measurement variables as well. However, the main concern was the Sampler and not the Measurement System, so the test design included only such measurement variables as could not be circumvented (Vials, Dissolution Method, and Aliquoting). The test was executed by, or under the direct oversight of, expert technologists. It thus did not explore the many important particulars of routine'' plant operations (such as Remote Sample Preparation or Laboratory Shift Operation).« less

  • This report is prepared as part of Technical/QA Task Plan WSRC-RP-97-351 which was issued in response to Technical Task Request HLW/DWPF/TTR-970132 submitted by DWPF. Presented in this report is a statistical analysis of DWPF Mock-up test data for evaluation of two new analytical methods which use insert samples from the existing HydragardTM sampler. The first is a new hydrofluoric acid based method called the Cold Chemical Method (Cold Chem) and the second is a modified fusion method.Either new DWPF analytical method could result in a two to three fold improvement in sample analysis time.Both new methods use the existing HydragardTMmore » sampler to collect a smaller insert sample from the process sampling system. The insert testing methodology applies to the DWPF Slurry Mix Evaporator (SME) and the Melter Feed Tank (MFT) samples.The insert sample is named after the initial trials which placed the container inside the sample (peanut) vials. Samples in small 3 ml containers (Inserts) are analyzed by either the cold chemical method or a modified fusion method. The current analytical method uses a HydragardTM sample station to obtain nearly full 15 ml peanut vials. The samples are prepared by a multi-step process for Inductively Coupled Plasma (ICP) analysis by drying, vitrification, grinding and finally dissolution by either mixed acid or fusion. In contrast, the insert sample is placed directly in the dissolution vessel, thus eliminating the drying, vitrification and grinding operations for the Cold chem method. Although the modified fusion still requires drying and calcine conversion, the process is rapid due to the decreased sample size and that no vitrification step is required.A slurry feed simulant material was acquired from the TNX pilot facility from the test run designated as PX-7.The Mock-up test data were gathered on the basis of a statistical design presented in SRT-SCS-97004 (Rev. 0). Simulant PX-7 samples were taken in the DWPF Analytical Cell Mock-up Facility using 3 ml inserts and 15 ml peanut vials. A number of the insert samples were analyzed by Cold Chem and compared with full peanut vial samples analyzed by the current methods. The remaining inserts were analyzed by the modified fusion method, for comparison to the current method, and also to obtain a calcine correction factor. The simulant was within 40 - 42 wt% solids in order to provide a rheology within the DWPF design range. The rheology at 42 wt% was approximately 47 dynes/cm2 yield stress at 251/4C.« less

  • The high-level radioactive waste currently stored in carbon steel tanks at the Savannah River Site (SRS) will be immobilized in a borosilicate glass in the Defense Waste Processing Facility (DWPF). The canistered waste will be sent to a geologic repository for final disposal. The Waste Acceptance Preliminary Specifications (WAPS) require the identification of any inorganic phases that may be present in the canister that may lead to internal corrosion of the canister or that could potentially adversely affect normal canister handling. During vitrification, volatilization of mixed (Na, K, Cs)Cl, (Na, K, Cs){sub 2}SO{sub 4}, (Na, K, Cs)BF{sub 4}, (Na, K){submore » 2}B{sub 4}O{sub 7} and (Na,K)CrO{sub 4} species from glass melt condensed in the melter off-gas and in the cyclone separator in the canister pour spout vacuum line. A full-scale DWPF prototypic canister filled during Campaign 10 of the SRS Scale Glass Melter was sectioned and examined. Mixed (NaK)CI, (NaK){sub 2}SO{sub 4}, (NaK) borates, and a (Na,K) fluoride phase (either NaF or Na{sub 2}BF{sub 4}) were identified on the interior canister walls, neck, and shoulder above the melt pour surface. Similar deposits were found on the glass melt surface and on glass fracture surfaces. Chromates were not found. Spinel crystals were found associated with the glass pour surface. Reference amounts of the halides and sulfates were found retained in the glass and the glass chemistry, including the distribution of the halides and sulfates, was homogeneous. In all cases where rust was observed, heavy metals (Zn, Ti, Sn) from the cutting blade/fluid were present indicating that the rust was a reaction product of the cutting fluid with glass and heat sensitized canister or with carbon-steel contamination on canister interior. Only minimal water vapor is present so that internal corrosion of the canister, will not occur.« less

  • The high-level radioactive waste currently stored in carbon steel tanks at the Savannah River Site (SRS) will be immobilized in a borosilicate glass in the Defense Waste Processing Facility (DWPF). The canistered waste will be sent to a geologic repository for final disposal. The Waste Acceptance Preliminary Specifications (WAPS) require the identification of any inorganic phases that may be present in the canister that may lead to internal corrosion of the canister or that could potentially adversely affect normal canister handling. During vitrification, volatilization of mixed (Na, K, Cs)Cl, (Na, K, Cs){sub 2}SO{sub 4}, (Na, K, Cs)BF{sub 4}, (Na, K){submore » 2}B{sub 4}O{sub 7} and (Na,K)CrO{sub 4} species from glass melt condensed in the melter off-gas and in the cyclone separator in the canister pour spout vacuum line. A full-scale DWPF prototypic canister filled during Campaign 10 of the SRS Scale Glass Melter was sectioned and examined. Mixed (NaK)CI, (NaK){sub 2}SO{sub 4}, (NaK) borates, and a (Na,K) fluoride phase (either NaF or Na{sub 2}BF{sub 4}) were identified on the interior canister walls, neck, and shoulder above the melt pour surface. Similar deposits were found on the glass melt surface and on glass fracture surfaces. Chromates were not found. Spinel crystals were found associated with the glass pour surface. Reference amounts of the halides and sulfates were found retained in the glass and the glass chemistry, including the distribution of the halides and sulfates, was homogeneous. In all cases where rust was observed, heavy metals (Zn, Ti, Sn) from the cutting blade/fluid were present indicating that the rust was a reaction product of the cutting fluid with glass and heat sensitized canister or with carbon-steel contamination on canister interior. Only minimal water vapor is present so that internal corrosion of the canister, will not occur.« less

  • The primary objective of this task is to determine just how representative Precipitate Reactor Bottom Tank (PRBT) samples taken from the Hydragard{trademark} prototypic liquid sampler are of the in-tank contents and also to determine the homogeneity of the in-tank contents. This shall be accomplished by a statistical design study sampling plan for paired contrasts of the analysis results of samples taken from: (1) the Hydragard{trademark} prototypic liquid sampler paired with the more fundamental grab sampler at the lower elevation for the Hydragard{trademark} prototypic liquid sampler accuracy and (2) the grab sampler at the lower elevation paired with the grab samplermore » at the upper elevation for the in-tank homogeneity. These measurements are paired together to sharpen the contrast so that, as nearly as possible, only the conditions of the effect under study will differ between the two. This split-plot'' arrangement provides increased precision for the contrast under study by canceling out common extraneous effects, thereby enabling the detection of smaller effects. The secondary objective of the task is to determine the level of influence of the major contributors to the overall uncertainty in the sample preparation and measurement process. These major steps include: preparation method (H{sub 2}SO{sub 4}-HF Titanium dissolution); aliquoting and dilution within a dissolution; measurement and long-term behavior of the ICP and AA instruments, as monitored by the measurement of standards and blanks embedded within each block of samples for the measurement sequence. This sampling task, therefore, is mostly devoted to determining the sampler characteristics and is not intended to provide a comprehensive estimate of the overall uncertainty affecting DWPF sample analysis in routine operation.« less