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Foster, T.

Publications and source records attributed to Foster, T..

13 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Characterization Results For The July 2018 H-Tank Farm 2h Evaporator Overhead Samples

This report contains the radioanalytical results of the 2H evaporator overhead sample received at Savannah River National Laboratory (SRNL) on July 16, 2018. Specifically, concentrations of 137 Cs, 90 Sr, and 129 I are reported and compared to the corresponding Waste Acceptance Criteria (WAC) limits of the Effluent Treatment Project (ETP) Waste Water Collection Tank (WWCT) (rev. 6). The radionuclide concentrations in the sample were found to be in compliance with the ETP WAC limits.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

H i Kinematics and Mass Distribution of Messier 33

A new deep H i survey of the galaxy Messier 33 is presented, based on observations obtained at the Dominion Radio Astrophysical Observatory. We observe a perturbed outer gas distribution and kinematics in M33, and confirm the disk warping as a significant twist of the major axis of the velocity field, although no strong tilt is measured, in agreement with previous work. Evidence for a new low-brightness H i component with anomalous velocity is reported. It harbors a large velocity scatter, as its kinematics both exceeds and lags the rotation of the disk, and leaks in the forbidden velocity zone of apparent counterrotation. The observations also reveal wide and multiple-peak H i profiles that can be partly explained by crowded orbits in the framework of the warp model. Asymmetric motions are identified in the velocity field as possible signatures of a lopsided potential and the warp. The mass distribution modeling of the hybrid Hα–H i rotation curve favors a cuspy dark matter halo with a concentration in disagreement with the ΛCDM dark halo mass–concentration relationship. The total mass enclosed in 23 kpc is 8 10{sup 10} M{sub ⊙}, of which 11% are stars and gas. At the virial radius of the cuspy halo, the resulting total mass is 5 10{sup 11} M{sub ⊙}, but with a baryonic mass fraction of only 2%. This strongly suggests a more realistic radius encompassing the total mass of M33 that is well smaller than the virial radius of the halo, possibly comparable to the size of the H i disk.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

Dissolution flowsheet for high flux isotope reactor fuel

As part of the Spent Nuclear Fuel (SNF) processing campaign, H-Canyon is planning to begin dissolving High Flux Isotope Reactor (HFIR) fuel in late FY17 or early FY18. Each HFIR fuel core contains inner and outer fuel elements which were fabricated from uranium oxide (U 3 O 8 ) dispersed in a continuous Al phase using traditional powder metallurgy techniques. Fuels fabricated in this manner, like other SNF’s processed in H-Canyon, dissolve by the same general mechanisms with similar gas generation rates and the production of H 2 . The HFIR fuel cores will be dissolved and the recovered U will be down-blended into low-enriched U. HFIR fuel was previously processed in H-Canyon using a unique insert in both the 6.1D and 6.4D dissolvers. Multiple cores will be charged to the same dissolver solution maximizing the concentration of dissolved Al. The objective of this study was to identify flowsheet conditions through literature review and laboratory experimentation to safely and efficiently dissolve the HFIR fuel in H-Canyon. Laboratory-scale experiments were performed to evaluate the dissolution of HFIR fuel using both Al 1100 and Al 6061 T6 alloy coupons. The Al 1100 alloy was considered a representative surrogate which provided an upper bound on the generation of flammable (i.e., H 2 ) gas during the dissolution process. The dissolution of the Al 6061 T6 alloy proceeded at a slower rate than the Al 1100 alloy and was used to verify that the target Al concentration in solution could be achieved for the selected Hg concentration. Mass spectrometry and Raman spectroscopy were used to provide continuous monitoring of the concentration of H 2 and other permanent gases in the dissolution offgas allowing the development of H 2 generation rate profiles. The H 2 generation rates were subsequently used to evaluate if a full HFIR core could be dissolved in an H-Canyon dissolver without exceeding 60% of the calculated lower flammability limit (LFL) for H 2 at a given Hg concentration.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2015

A CGPS look at the spiral structure of the outer Milky Way. I. Distances and velocities to star-forming regions

We present a new catalog of spectrophotometric distances and line of sight systemic velocities to 103 H ii regions between 90{sup ∘}⩽ℓ⩽195{sup ∘} (longitude quadrants II and part of III). Two new velocities for each region are independently measured using 1 arcmin resolution 21 cm H i and 2.6 mm {sup 12}CO line maps (from the Canadian Galactic Plane Survey and Five College Radio Astronomy Observatory Outer Galaxy Surveys) that show where gaseous shells are observed around the periphery of the ionized gas. Known and neighboring O- and B-type stars with published UBV photometry and MK classifications are overlaid onto 21 cm continuum maps, and those stars observed within the boundary of the H ii emission (and whose distance is not more than three times the standard deviation of the others) are used to calculate new mean stellar distances to each of the 103 nebulae. Using this approach of excluding distance outliers from the mean distance to a group of many stars in each H ii region lessens the impact of anomalous reddening for certain individuals. The standard deviation of individual stellar distances in a cluster is typically 20% per stellar distance, and the error in the mean distance to the cluster is typically ±10%. Final mean distances of nine common objects with very long baseline interferometry parallax distances show a 1:1 correspondence. Further, comparison with previous catalogs of H ii regions in these quadrants shows a 50% reduction in scatter for the distance to Perseus spiral arm objects in the same region, and a reduction by ∼1/√2 in scatter around a common angular velocity relative to the Sun Ω−Ω{sub 0}(km s{sup −1} kpc{sup −1}). The purpose of the catalog is to provide a foundation for more detailed large-scale Galactic spiral structure and dynamics (rotation curve, density wave streaming) studies in the 2nd and 3rd quadrants, which from the Sun’s location is the most favorably viewed section of the Galaxy.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Results of Hg Speciation Testing on 2Q15 Tank 50 WAC and Cs-Decontaminated Tank 21 Waste Samples

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team. The fourth shipment of samples was designated to include 2Q15 Tank 50 WAC material (HTF-50-15-39) collected on April 7, 2015, and Tank 21 material (HTF-21-15-32, HTF-21-15-36, and HTF-21-15-37) the first collected on March 9 and the second two collected on April 6, 2015. The combined samples were subjected to Cs-decontamination through the use of MCU solvent. Samples were collected with the minimum possible free headspace and refrigerated prior to final dilution.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Results of Hg Speciation Testing on 2Q15 Tank 50 WAC and Cs-Decontaminated Tank 21 Waste Samples (Rev.1)

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team. The fourth shipment of samples was designated to include 2Q15 Tank 50 WAC material (HTF-50-15-39) collected on April 7, 2015, and Tank 21 material (HTF-21-15-32, HTF-21-15-36, and HTF-21-15-37) the first collected on March 9 and the second two collected on April 6, 2015. The combined samples were subjected to Cs-decontamination through the use of MCU solvent. Samples were collected with the minimum possible free headspace and refrigerated prior to final dilution.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Results of HG Speciation Testing on Tank 43 and 2H Evaporator Overhead Tank (OHT-2) Materials

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team. The eighth shipment of samples was designated to include two Tank 43 (2H Evaporator System Feed Tank) samples: a surface sample (HTF-43-15-52) and a variable depth sample taken at 161” (HTF-43-15-54). The third sample submitted was from the 2H Evaporator Overhead Tank (OHT) #2. All samples were received by SRNL on May 11, 2015. The OHT-2 was not placed in the SRNL Shielded Cells but was instead placed in a refrigerator in 773-A, B-wing upon receipt and kept at 4°C. The Tank 43 samples were left in their stainless steel dip bottles until they were opened and an aliquot of each diluted 1:10 with Eurofins deionized water on June 3, 2015. Following initial dilution in the Shielded Cells, the diluted Tank 43 samples were immediately moved to refrigeration and kept in the dark until prepared for shipment to Eurofins.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

SCM Paste Samples Exposed To Aggressive Solutions. Cementitious Barriers Partnership

This report summarizes experimental work performed by SIMCO Technologies Inc. (SIMCO) as part of the Cementitious Barriers Partnership (CBP) project. The test series followed an experimental program dedicated to the study of ordinary Portland cement (OPC) hydrated cement pastes exposed to aggressive solutions. In the present study, the scope is extended to hydrated cement pastes incorporating supplementary cementitious materials (SCM) such as fly ash and ground granulated blast furnace slag (GGBFS). Also, the range of aggressive contact solutions was expanded. The experimental program aimed at testing aggressive contact solutions that more closely mimic the chemical composition of saltstone pore solution. Five different solutions, some of which incorporated high levels of carbonate and nitrate, were placed in contact with four different hydrated cement paste mixes. In all solutions, 150 mmol/L of SO 4 2– (14 400 ppm) were present. The solutions included different pH conditions and different sodium content. Two paste mixes were equivalent to Vault 1/4 and Vault 2 concrete mixes used at SRS in storage structures. Two additional paste mixes, cast at the same water-to-cement ratio and using the same cements but without SCMs, were also tested. The damage evolution in samples was monitored using ultrasonic pulse velocity (UPV) and mass measurements. After three and twelve months of exposure conditions, samples were taken out of solution containers and analyzed to perform migration tests and porosity measurements. Globally, results were in line with the previous study and confirmed that high pH may limit the formation of some deleterious phases like gypsum. In this case, ettringite may form but is not necessarily associated with damage. However, the high concentration of sodium may be associated with the formation of an AFm-like mineral called U-phase. The most significant evidences of damage were all associated with the Vault 2 paste analog. This material proved very sensitive to high pH. All measurement techniques used to monitor and evaluate damage to samples indicated significant alterations to this mix when immersed in contact solutions containing sodium hydroxide. It was hypothesized that the low cement content, combined with high silica content coming from silica fume, fly ash and GGBFS led to the presence unreacted silica. It is possible that the pozzolanic reaction of these SCMs could not be activated due to the low alkali content, a direct consequence of low cement content. In this scenario, the material end up having a lot of silica available to react upon contact with sodium hydroxide, possibly forming a gel that may be similar to the gel formed in alkali-silica reactions. This scenario needs further experimental confirmation, but it may well explain the poor behavior of mix PV2 in presence of NaOH.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

A RELATION BETWEEN THE WARM NEUTRAL AND IONIZED MEDIA OBSERVED IN THE CANADIAN GALACTIC PLANE SURVEY

We report on a comparison between 21 cm rotation measure (RM) and the optically thin atomic hydrogen column density (N{sub H{sub I}}({tau} {yields} 0)) measured toward unresolved extragalactic sources in the Galactic plane of the northern sky. H I column densities integrated to the Galactic edge are measured immediately surrounding each of nearly 2000 sources in 1 arcmin 21 cm line data, and are compared to RMs observed from polarized emission of each source. RM data are binned in column density bins 4 Multiplication-Sign 10{sup 20} cm{sup -2} wide, and one observes a strong relationship between the number of hydrogen atoms in a 1 cm{sup 2} column through the plane and the mean RM along the same line of sight and path length. The relationship is linear over one order of magnitude (from 0.8 to 14 Multiplication-Sign 10{sup 21} atoms cm{sup -2}) of column densities, with a constant RM/N{sub H{sub I}}{approx} -23.2 {+-} 2.3 rad m{sup -2}/10{sup 21} atoms cm{sup -2}, and a positive RM of 45.0 {+-} 13.8 rad m{sup -2} in the presence of no atomic hydrogen. This slope is used to calculate a mean volume-averaged magnetic field in the second quadrant of (B{sub Parallel-To }) {approx}1.0 {+-} 0.1 {mu}G directed away from the Sun, assuming an ionization fraction of 8% (consistent with the warm-neutral medium; WNM). The remarkable consistency between this field and (B) = 1.2 {mu}G found with the same RM sources and a Galactic model of dispersion measures (DMs) suggests that electrons in the partially ionized WNM are mainly responsible for pulsar DMs, and thus the partially ionized WNM is the dominant form of the magneto-ionic interstellar medium.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1978

Variable mixer propulsion cycle

A design technique, method and apparatus are delineated for controlling the bypass gas stream pressure and varying the bypass ratio of a mixed flow gas turbine engine in order to achieve improved performance. The disclosed embodiments each include a mixing device for combining the core and bypass gas streams. The variable area mixing device permits the static pressures of the core and bypass streams to be balanced prior to mixing at widely varying bypass stream pressure levels. The mixed flow gas turbine engine therefore operates efficiently over a wide range of bypass ratios and the dynamic pressure of the bypass stream is maintained at a level which will keep the engine inlet airflow matched to an optimum design level throughout a wide range of engine thrust settings.

Rundell, D. J.↗
NASA NTRS1977

Variable cycle gas turbine engines

A technique, method, and apparatus were designed for varying the bypass ratio and modulating the flow of a gas turbine engine in order to achieve improved mixed mission performance. Embodiments include gas flow control system for management of core and bypass stream pressure comprising diverter valve means downstream of the core engine to selectively mix or separate the core and bypass exhaust streams. The flow control system may also include variable geometry means for maintaining the engine inlet airflow at a matched design level at all flight velocities. Earth preferred embodiment thus may be converted from a high specific thrust mixed flow cycle at supersonic velocities to a lower specific thrust separated flow turbofan system at subsonic velocities with a high degree of flow variability in each mode of operation.

Johnson, J. E.↗