Gas monitoring systems in support of Waste tank 241-SY-101 hydrogen mitigation task

Twenty-four hazardous waste storage tanks at the Hanford Site in Richland Washington,,are identified as having the potential to build up gases, including hydrogen, nitrous oxide and ammonia, to a flammable level. Because this behavior was not addressed adequately by the facility Safety Analyses, the US Department of Energy (DOE) declared an Unreviewed Safety Question, placing the tanks on a Flammable Gas Watch List. Westinghouse Hanford Company (WHC) identified Waste tank 241-SY-101 (SY-101) as presenting the most serious safety concern. Generated gases collect in the sludge layer near the bottom of the tank. The accumulation creates a buoyancy that eventually overcomes the density and bonding strength of the bottom layer. When this happens, the gases detach and travel upward through a liquid layer to the vapor space above the tank crust. This event typically occurs at 90-day intervals and is completed within a couple hours. This allows a rapid buildup of hydrogen to potentially flammable levels in the tank vapor space

Clean option: An alternative strategy for Hanford Tank Waste Remediation. Volume 1, Overview

Plans for remediation of the Hanford underground storage tanks are currently undergoing reevaluation. As part of this process, many options are being considered for the Tank Waste Remediation System (MRS). The ``clean option`` described here proposes an aggressive waste processing strategy to achieve the three ma or objectives: Greatly reduce the volume of high-level waste (HLW) to lessen demands on geologic repository space; decrease by several orders of magnitude the amount of radioactivity and toxicity now in the waste tanks that will be left permanently onsite as low-level solid waste (LLW); and accomplish the first two objectives without significantly increasing the total amount of waste for disposal. The study discussed here focuses on process chemistry, as it provides the foundation for achieving the clean option objectives. Because demonstrated separation steps have been identified and connected in a way that meets these objectives, the study concludes that the process chemistry rests on a firm technical basis

TWRS hydrogen mitigation gas characterization system design and fabrication engineering task plan

The flammable gas watch-list (FGWL) tanks, which have demonstrated a gas release event (GRE) exceeding 0.625% hydrogen by volume will require additional characterization. The purpose of this additional characterization is to accurately measure the flammable and hazardous gas compositions and resulting lower flammability limit (LFL) of the tank vapor space during baseline and GRE emissions. Data from this characterization will help determine methods to resolve the unreviewed safety questions for the FGWL tanks. This document details organization responsibilities and engineering requirements for the design and fabrication of two gas characterization systems used to monitor flammable gas watch-list tanks

Gas characterization system functional design criteria

This is the functional design criteria for the gas characterization systems being placed on selected flammable gas watch-list tanks in support of the hydrogen mitigation tests

Assessment of the performance potential of the martensitic alloy HT-9 for liquid-metal fast-breeder-reactor applications

Martensitic stainless steels appear to provide attractive alternatives to austenitic stainless steels for liquid metal fast breeder reactors (LMFBR). The United States National Cladding/Duct (NCD) Materials Development Program has selected Sandvik alloy HT-9 (12CrMoW) as one of six prime candidate alloys for advanced in-core structural materials having very high peak burnup capabilities. The NCD program, since 1974, has been accumulating engineering data for HT-9. Properties include swelling, irradiation creep and microstructure as a function of fluence, postirradiation mechanical properties, thermal creep, sodium compatibility and hardware fabrication technology. Tests results are presented

Length changes in FTR prototypic cladding irradiated in EBR-II to 1 x 10/sup 22/ N/CM/sup 2/, E > 0. 1 MeV (PIN B-65)(RM-24)

Swelling in prototypic FTR cladding and duct specimens is being determined from a series of three irradiations designed to cover a range of temperatures approximately 800 to 1500/sup 0/F and peak fluences of approximately 1 x 10/sup 22/, 6 x 10/sup 22/, and 1 x 10/sup 23/ n/cm/sup 2/. The length change measurements for the low fluence irradiation have been completed and are summarized in this report. No swelling, only shrinkage, was found in the 20 percent cold worked Type 316 stainless steel cladding specimens. This shrinkage is of the same magnitude and has the same temperature dependency as unirradiated, control samples. Annealed specimens did swell slightly. Details of the experiment and analysis are given