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Real-Time Monitoring of Low-Level Mixed-Waste Loading during Polyethylene Microencapsulation using Transient Infrared Spectroscopy (open access)

Real-Time Monitoring of Low-Level Mixed-Waste Loading during Polyethylene Microencapsulation using Transient Infrared Spectroscopy

In polyethylene microencapsulation, low-level mixed waste (LLMW) is homogenized with molten polyethylene and extruded into containers, resulting in a lighter, lower-volume waste form than cementation and grout methods produce. Additionally, the polyethylene-based waste form solidifies by cooling, with no risk of the waste interfering with cure, as may occur with cementation and grout processes. We have demonstrated real-time monitoring of the polyethylene encapsulation process stream using a noncontact device based on transient infrared spectroscopy (TIRS). TIRS can acquire mid-infrared spectra from solid or viscous liquid process streams, such as the molten, waste-loaded polyethylene stream that exits the microencapsulation extruder. The waste loading in the stream was determined from the TIRS spectra using partial least squares techniques. The monitor has been demonstrated during the polyethylene microencapsulation of nitrate-salt LLMW and its surrogate, molten salt oxidation LLMW and its surrogate, and flyash. The monitor typically achieved a standard error of prediction for the waste loading of about 1% by weight with an analysis time under 1 minute.
Date: April 15, 1999
Creator: Jones, Roger W.; Kalb, Paul D.; McClelland, John F. & Ochiai, Shukichi
System: The UNT Digital Library
From separations to reconstitution - a short history of Plutonium in the U.S. and Russia (open access)

From separations to reconstitution - a short history of Plutonium in the U.S. and Russia

During the cold war plutonium was produced in reactors in both the US and Russia. It was then separated from the residual uranium and fission products by a variety of precipitation processes, such as Bismuth Phosphate, Redox, Butex, Purex, etc. in the US and uranium acetate and Purex in Russia. After a period of time in the field, plutonium weapons were recycled and the plutonium re-purified and returned to weapons. purification was accomplished by a variety of aqueous and molten salt processes, such as nitric-hydrofluoric acid dissolution followed by anion exchange, Purex modifications, molten salt extraction, electrorefining, etc. in the US and nitric acid dissolution or sodium hydroxide fusion followed by anion exchange in Russia. At the end of the Cold War, plutonium production of weapons-grade plutonium was cut off in the US and is expected to be cut off in Russia shortly after the turn of the century. Now both countries are looking at methods to reconstitute plutonium with fission products to render it no longer useful for nuclear weapons. These methods include immobilization in a ceramic matrix and then encasement in fission product laden glass, irradiation of MOX fuel, and disposal as waste in WIPP in the US …
Date: April 15, 1999
Creator: Gray, L W
System: The UNT Digital Library
Technology Development, Validation, and Transfer Via the FAA Airworthiness Assurance Validation (open access)

Technology Development, Validation, and Transfer Via the FAA Airworthiness Assurance Validation

In 1991, the Federal Aviation Administration (FAA) established an Airworthiness Assurance NDI Validation Center (AANC) at Sandia National Laboratories. Its primary mission is to support technology development, validation, and transfer to industry in order to enhance the airworthiness and improve the aircraft maintenance practices of the U.S. commercial aviation industry. The Center conducts projects in a myriad of engineering disciplines. The results are placed in the public domain so that the industry at-large can reap the benefits of FAA-funded Research and Development efforts. To support the Center's goals, the FAA/AANC has set up a hangar facility at the Albuquerque International Airport which contains a collection of transport and commuter aircraft as well as other test specimens. The facility replicates a working maintenance environment by incorporating both the physical inspection difficulties as well as the environmental factors which influence maintenance reliability.
Date: April 15, 1999
Creator: Perry, Richard L.
System: The UNT Digital Library
Bunch cleaning strategies and experiments at the Advanced Photon Source. (open access)

Bunch cleaning strategies and experiments at the Advanced Photon Source.

The Advanced Photon Source (APS) design incorporated a positron accumulator ring (PAR) as part of the injector chain. In order to increase reliability and accommodate other uses of the injector, APS will run with electrons, eliminating the need for the PAR, provided another method of eliminating rf bucket pollution in the APS is found. Satellite bunches captured from an up to 30-ns-long beam from the linac need to be removed in the injector synchrotron and storage ring. The bunch cleaning method considered here relies on driving a stripline kicker with an amplitude modulated (AM) carrier signal where the carrier is at a revolution harmonic sideband corresponding to the vertical tune. The envelope waveform is phased so that all bunches except a single target bunch (eventually to be injected into the storage ring) are resonated vertically into a scraper. The kicker is designed with a large enough shunt impedance to remove satellite bunches from the injection energy of 0.4 GeV up to 1 GeV. Satellite bunch removal in the storage ring relies on the single bunch current tune shift resulting from the machine impedance. Small bunches remaining after initial preparation in the synchrotron may be removed by driving the beam vertically …
Date: April 15, 1999
Creator: Sereno, N. S.
System: The UNT Digital Library
Methods for incorporating effects of LWR coolant environment into ASME code fatigue evaluations. (open access)

Methods for incorporating effects of LWR coolant environment into ASME code fatigue evaluations.

The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Appendix I to Section HI of the Code specifies design fatigue curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Recent test data illustrate potentially significant effects of LWR environments on the fatigue resistance of carbon and low-alloy steels and austenitic stainless steels (SSs). Under certain loading and environmental conditions, fatigue lives of carbon and low-alloy steels can be a factor of {approx}70 lower in an LWR environment than in air. These results raise the issue of whether the design fatigue curves in Section III are appropriate for the intended purpose. This paper presents the two methods that have been proposed for incorporating the effects of LWR coolant environments into the ASME Code fatigue evaluations. The mechanisms of fatigue crack initiation in carbon and low-alloy steels and austenitic SSs in LWR environments are discussed.
Date: April 15, 1999
Creator: Chopra, O. K.
System: The UNT Digital Library
SITE-WIDE PHYSICAL INVENTORY TAKING AT IPPE. (open access)

SITE-WIDE PHYSICAL INVENTORY TAKING AT IPPE.

As part of the US-Russia Cooperative Program of Material Protection, Control and Accounting, staff members of the Institute of Physics and Power Engineering (IPPE) have implemented procedures for taking physical inventory of nuclear materials at many of the facilities within the IPPE site. These include both large facilities, with substantial inventories and requiring dedicated inventory equipment and computers, and small facilities, with smaller amounts of material and subject to inventory by portable equipment. The experience to date demonstrates good progress toward the goal of regular PITs for the most attractive nuclear materials at IPPE.
Date: April 15, 1999
Creator: Poplavko, V. Ya.
System: The UNT Digital Library