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Title: The effect of dilution on the gas retention behavior of Tank 241-SY- 103 waste

Abstract

Twenty-five of the 177 underground waste storage tanks on the Hanford Site have been placed on the Flammable Gas watch list. These 25 tanks, containing high-level waste generated during plutonium and uranium processing, have been identified as potentially capable of accumulating flammable gases above the lower flammability limit (Babad et al. 1991). In the case of Tanks 241-SY-101 and 241-SY-103, it has been proposed that diluting the tank waste may mitigate this hazard (Hudson et al. 1995; Stewart et al. 1994). The effect of dilution on the ability of waste from Tank 241-SY-103 to accumulate gas was studied at Pacific Northwest National Laboratory. A similar study has been completed for waste from Tank 241-SY-101 (Bredt et al. 1995). Because of the additional waste-storage volume available in Tank 241-SY-103 and because the waste is assumed to be similar to that currently in Tank 241-SY-101, Tank 241-SY-103 became the target for a demonstration of passive mitigation through in-tank dilution. In 1994, plans for the in-tank dilution demonstration were deferred pending a decision on whether to pursue dilution as a mitigation strategy. However, because Tank 241-SY-103 is an early retrieval target, determination of how waste properties vary with dilution will still be required.

Authors:
;
Publication Date:
Research Org.:
Pacific Northwest Lab., Richland, WA (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
192554
Report Number(s):
PNL-10893
ON: DE96004519; TRN: 96:008230
DOE Contract Number:
AC06-76RL01830
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Jan 1996
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; GASES; FLAMMABILITY; HIGH-LEVEL RADIOACTIVE WASTES; RADIOACTIVE WASTE STORAGE; TANKS; RETENTION; SAMPLING; MONITORING

Citation Formats

Bredt, P.R., and Tingey, S.M.. The effect of dilution on the gas retention behavior of Tank 241-SY- 103 waste. United States: N. p., 1996. Web. doi:10.2172/192554.
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Bredt, P.R., & Tingey, S.M.. The effect of dilution on the gas retention behavior of Tank 241-SY- 103 waste. United States. doi:10.2172/192554.
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Bredt, P.R., and Tingey, S.M.. Mon . "The effect of dilution on the gas retention behavior of Tank 241-SY- 103 waste". United States. doi:10.2172/192554. https://www.osti.gov/servlets/purl/192554.
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@article{osti_192554,
title = {The effect of dilution on the gas retention behavior of Tank 241-SY- 103 waste},
author = {Bredt, P.R. and Tingey, S.M.},
abstractNote = {Twenty-five of the 177 underground waste storage tanks on the Hanford Site have been placed on the Flammable Gas watch list. These 25 tanks, containing high-level waste generated during plutonium and uranium processing, have been identified as potentially capable of accumulating flammable gases above the lower flammability limit (Babad et al. 1991). In the case of Tanks 241-SY-101 and 241-SY-103, it has been proposed that diluting the tank waste may mitigate this hazard (Hudson et al. 1995; Stewart et al. 1994). The effect of dilution on the ability of waste from Tank 241-SY-103 to accumulate gas was studied at Pacific Northwest National Laboratory. A similar study has been completed for waste from Tank 241-SY-101 (Bredt et al. 1995). Because of the additional waste-storage volume available in Tank 241-SY-103 and because the waste is assumed to be similar to that currently in Tank 241-SY-101, Tank 241-SY-103 became the target for a demonstration of passive mitigation through in-tank dilution. In 1994, plans for the in-tank dilution demonstration were deferred pending a decision on whether to pursue dilution as a mitigation strategy. However, because Tank 241-SY-103 is an early retrieval target, determination of how waste properties vary with dilution will still be required.},
doi = {10.2172/192554},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 1996},
month = {Mon Jan 01 00:00:00 EST 1996}
}
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Technical Report:
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DOI:  10.2172/192554
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  • ; ;
    The effect of dilution on gas retention in waste from Tank 241-SY-101 was investigated. A composite sample was prepared from material collected during the Window ``C`` and Window ``E`` sampling events. The composite contained material from both the convective and nonconvective layer in the proportions existing in the tank. Operation of the mixer pump in Tank 241-SY-101 has homogenized the tank material, and dilution of the current waste would require additional mixing; therefore, no attempt was made to use unhomogenized tank waste to prepare the composite. The composite was diluted with 2 M NaOH at ratios of 0.5:1, 0.75: 1,more » 1:1, and 3:1 per volume (2 M NaOH:tank waste).« less

  • ; ; ; ...
    Research at Pacific Northwest National Laboratory (PNNL) has probed the physical mechanisms and waste properties that contribute to the retention and release of flammable gases from radioactive waste stored in underground tanks at Hanford. This study was conducted for Westinghouse Hanford Company as part of the PNNL Flammable Gas Project. The wastes contained in the tanks are mixes of radioactive and chemical products, and some of these wastes are known to generate mixtures of flammable gases, including hydrogen, nitrous oxide, and ammonia. Because these gases are flammable, their retention and episodic release pose a number of safety concerns.

  • ;
    The Hanford Site has 149 single-shell tanks (SSTs) and 28 double-shell tanks (DSTs) containing radioactive wastes that are complex mixes of radioactive and chemical products. Some of these wastes are known to generate mixtures of flammable gases, including hydrogen, nitrous oxide, and ammonia. Nineteen of these SSTs and six of the DSTs have been placed on the Flammable Gas Watch List because they are known or suspected, in all but one case, to retain these flammable gases. Because these gases are flammable, their retention and episodic release pose a number of safety concerns. Understanding the physical mechanisms and waste propertiesmore » that contribute to the retention and release of these gases will help to resolve the Flammable Gas Safety Issue. The strength of the waste plays a central role in the mechanisms of both bubble retention and bubble release. While recent in-situ measurements from the ball rheometer have provided results for five of the DSTs, waste strength measurements are typically not available for any of the SSTs or for the DSTs that have not been characterized with the ball rheometer. The overall purpose of this study is to develop a method to obtain strength estimates for actual wastes from observations of the wastes` behavior during extrusion from core samplers. The first objective of the study was to quantify waste behavior during horizontal extrusion by documenting the extrusion behavior of simulants with known strengths; the second was to estimate the strength of actual waste based on these simulant standards. Results showed a reproducible extrusion behavior for bentonite clay and kaolin/Ludox{reg_sign} simulants over strengths ranging from 30 to 6,500 Pa. The extrusion behavior was documented with both video recordings and still images. Based on these visual standards, strength estimates were made for wastes from DSTs 241-SY-103, 241-AW-101, and 241-AN-103 and SST 241-S-102.« less

  • Tank 241-SY-103 is on the Flammable Gas Watch List. The waste in this tank behaves similarly to that in tank 241-Sy-101. Both show slurry growth and periodic surface level drops. However, the surface level drops are much smaller than those in tank 101-SY. A standard hydrogen monitoring system (SHMS) was recently installed in tank 103-SY, and waste auger samples were recently taken. This document covers the characterization results to date for the auger samples, and the behavior of the tank waste during both steady state periods and gas release events.

  • ; ; ; ...
    This report summarizes progress made in evaluating mechanisms by which flammable gases are generated in Hanford double-shell tank wastes, based on the results of laboratory tests using actual waste from Tank 241-SY-103. The objective of this work is to establish the identity and stoichiometry of degradation products formed in actual tank wastes by thermal and radiolytic processes as a function of temperature. The focus of the gas generation tests on Tank 241-SY-103 samples is first the effect of temperature on gas generation (volume and composition). Secondly, gas generation from irradiation of Tank 241-SY-103 samples at the corresponding temperatures as themore » thermal-only treatments will be measured in the presence of an external radiation source (using a {sup 137}Cs capsule). The organic content will be measured on a representative sample prior to gas generation experiments and again at the termination of heating and irradiation. The gas generation will be related to the extent of organic species consumption during heating. Described in this report are experimental methods used for producing and measuring gases generated at various temperatures from highly radioactive actual tank waste, and results of gas generation from Tank 241-SY-103 waste taken from its convective layer. The accurate measurement of gas generation rates from actual waste from highly radioactive waste tanks is needed to assess the potential for producing and storing flammable gases within the waste tanks. This report addresses the gas generation capacity of the waste from the convective layer of Tank 241-SY-103, a waste tank listed on the Flammable Gas Watch List due to its potential for flammable gas accumulation above the flammability limit.« less