Simulation of Hanford Tank 241-C-106 Waste Release into Tank 241-Y-102

Recknagle, KP; Onishi, Yasuo

doi:10.2172/6799

Cited by 18 publications

(33 citation statements)

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“…It is noteworthy that the radial velocity is ≈0.1 km s −1 at r ∼ 0.1 pc, in excellent agreement with the observed infall motions of L1544 by Tafalla et al (1998). The predicted radial velocities also compare well with the observed infall motions near the starless molecular cloud core MC27 in Taurus, where speeds of 0.2-0.3 km s −1 have been detected at r 2000-3000 au (∼10 −2 pc) (Onishi, Mizuno & Fukui 1999). The radial velocities outside the supercritical core, where the gas is magnetically supported, remain subsonic by a factor of a few.…”

Section: Velocitiessupporting

confidence: 80%

The non-isothermal stage of magnetic star formation - II. Results

Kunz

Mouschovias

2010

Monthly Notices of the Royal Astronomical Society

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In a previous paper we formulated the problem of the formation and evolution of fragments (or cores) in magnetically supported, self‐gravitating molecular clouds in axisymmetric geometry, accounting for the effects of ambipolar diffusion and Ohmic dissipation, grain chemistry and dynamics, and radiative transfer. Here, we present results of star formation simulations that accurately track the evolution of a protostellar fragment over 11 orders of magnitude in density (from 300 to ≈ 1014 cm−3), i.e. from the early ambipolar‐diffusion‐initiated fragmentation phase, through the magnetically supercritical, dynamical‐contraction phase and the subsequent magnetic decoupling stage, to the formation of a protostellar core in near hydrostatic equilibrium. As found by Fiedler & Mouschovias, gravitationally‐driven ambipolar diffusion leads to the formation and subsequent dynamic contraction of a magnetically supercritical core. Moreover, we find that ambipolar diffusion, not Ohmic dissipation, is responsible for decoupling all the species except the electrons from the magnetic field, by a density of ≈ 3 × 1012 cm−3. Magnetic decoupling precedes the formation of a central stellar object and ultimately gives rise to a concentration of magnetic flux (a ‘magnetic wall’) outside the hydrostatic core – as also found by Tassis & Mouschovias through a different approach. At approximately the same density at which Ohmic dissipation becomes more important than ambipolar diffusion (>rsim 7 × 1012 cm−3), the grains carry most of the electric charge as well as the electric current. The prestellar core remains disc like down to radii ∼ 10 au, inside which thermal pressure becomes important. The magnetic flux problem of star formation is resolved for at least strongly magnetic newborn stars by this stage of the evolution, i.e. by a central density ≈ 1014 cm−3. The hydrostatic core has radius ≈ 2 au, density ≈ 1014 cm−3, temperature ≈ 300 K, magnetic field strength ≈ 0.2 G, magnetic flux ≈ 5 × 1026 Mx, luminosity ∼ 10−3 L⊙ and mass ∼ 10−2 M⊙.

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Section: Velocitiessupporting

confidence: 80%

The non-isothermal stage of magnetic star formation - II. Results

Kunz

Mouschovias

2010

Monthly Notices of the Royal Astronomical Society

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“…• mobilization and mixing of sediment in SY-102 • concentration of plutonium in the pump housings in AZ-101 during sediment mobilization and mixing (Onishi and Recknagle 1997b) • adequacy of a single mixer pump to fully mix wastes in AP-102 and AP-104 (Onishi and Recknagle 1998) • ability of a densitometer in AY-102 to represent the mass of solids transferred during retrieval of C-106 (Onishi and Recknagle 1999) • mobilization and mixing of sediment in AZ-102 (Onishi et al 2000) • mobilization and mixing of sediment in AN-105 after transfer and dilution (Onishi et al 2003a) • feasibility of a single mixer pump to adequately mobilize and mix AN-101 (Onishi et al 2003b) • liquid waste mixing of S-112 and SY-101 (Onishi et al 2003c) • feasibility of a single mixer pump to adequately mobilize and mix AY-102 (Onishi and Wells 2004).…”

Section: Cfd Studiesmentioning

confidence: 99%

The Role of Cohesive Particle Interactions on Solids Uniformity and Mobilization During Jet Mixing: Testing Recommendations

Gauglitz¹,

Wells²,

Bamberger³

et al. 2010

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Executive SummaryRadioactive waste that is currently stored in large underground tanks at the Hanford Site will be staged in selected double-shell tanks (DSTs) and then transferred to the Waste Treatment and Immobilization Plant (WTP). Before being transferred, the waste will be mixed, sampled, and characterized to determine if the waste composition meets the waste feed specifications. Washington River Protection Solutions (WRPS) is conducting a Tank Mixing and Sampling Demonstration Program to determine the mixing effectiveness of the current baseline mixing system that uses two jet mixer pumps to mobilize and mix waste in DSTs and to determine the adequacy of the planned sampling method. The overall purpose of the demonstration program is to mitigate the technical risk associated with the mixing and sampling systems meeting the feed certification requirements for transferring waste to the WTP.A critical aspect of meeting the feed certification requirements is ensuring that the collected samples will adequately represent the contents of the tank and that all batches of transferred waste are sufficiently uniform so that they all are equivalent to the characterized samples. However, the tank waste contains slurries of solid particles that settle and may become progressively more concentrated towards the bottom of the tank. Obtaining a perfectly uniform distribution of waste in the DSTs with a mixing system may not be possible. To determine how close this ideal can be approached, the expected performance of the DST mixing and sampling systems must be quantified. There have been a number of laboratory studies and full-scale tank farm studies that evaluated mixing behavior; these studies are discussed later in this report. However, these studies do not provide adequate quantitative information to evaluate the performance of the planned sampling and the batch uniformity. Accordingly, WRPS' demonstration program is focusing specifically on quantifying the uniformity of samples and batch transferred material to reduce the technical risk associated with these systems.The first phase of the demonstration program is to conduct scaled tests that appropriately match fullscale behavior and to evaluate sampling methodologies and the uniformity of batch transfers. The initial scaled testing will use non-cohesive particles where the particles do not have cohesive interactions that would cause the particles to stick together. The purpose of this report is to analyze existing data and evaluate whether scaled mixing tests with cohesive simulants are needed to meet the overall objectives of the small-scale mixing demonstration program. This evaluation will focus on estimating the role of cohesive particle interactions on various physical phenomena that occur in parts of the mixing process. A specific focus of the evaluation will be on the uniformity of suspended solids in the mixed region.The evaluation shows that cohesive particle interaction will have multiple effects through a number of different mechanisms. Some of the effects ...

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“…The line-of-sight component of the magnetic field is measured using Zeeman observations (Crutcher et al, 1993). L1521F (MC27; Codella et al, 1997;Onishi et al, 1999;Lee et al, 2001) is located in the Taurus starforming region at a distance of 140 pc (Loinard et al, 2005;Torres et al, 2007). This core contains a very low luminosity object (VeLLO) L1521F-IRS with bolometric luminosty of L = 0.05 L ⊙ (Terebey et al, 2006;Bourke et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

First Sub-parsec-scale Mapping of Magnetic Fields in the Vicinity of a Very-low-luminosity Object, L1521F-IRS

Soam

Lee

Andersson

et al. 2019

ApJ

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L1521F is found to be forming multiple cores and it is cited as an example of the densest core with an embedded VeLLO in a highly dynamical environment. We present the core-scale magnetic fields (B-fields) in the near vicinity of the VeLLO L1521F-IRS using submm polarization measurements at 850 µm using JCMT POL-2. This is the first attempt to use high-sensitivity observations to map the sub-parsec scale B-fields in a core with a VeLLO. The B-fields are ordered and very well connected to the parsec-scale field geometry seen in our earlier optical polarization observations and the large-scale structure seen in Planck dust polarization. The core scale B-field strength estimated using Davis-Chandrasekhar-Fermi relation is 330 ± 100 µG which is more than ten times of the value we obtained in the envelope (envelope in this paper is "core envelope"). This indicates that B-fields are getting stronger on smaller scales. The magnetic energies are found to be 1 to 2 orders of magnitude higher than non-thermal kinetic energies in the envelope and core. This suggests that magnetic fields are more important than turbulence in the energy budget of L1521F. The mass-to-flux ratio of 2.3±0.7 suggests that the core is magnetically-supercritical. The degree of polarization is steadily decreasing towards the denser part of the core with a power law slope of -0.86.

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Simulation of Hanford Tank 241-C-106 Waste Release into Tank 241-Y-102

Cited by 18 publications

References 0 publications

The non-isothermal stage of magnetic star formation - II. Results

The non-isothermal stage of magnetic star formation - II. Results

The Role of Cohesive Particle Interactions on Solids Uniformity and Mobilization During Jet Mixing: Testing Recommendations

First Sub-parsec-scale Mapping of Magnetic Fields in the Vicinity of a Very-low-luminosity Object, L1521F-IRS

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