An Evaluation of the PBF LOFT Lead Rod Test Results Concerning Surface Thermocouple Perturbation Effects (open access)

An Evaluation of the PBF LOFT Lead Rod Test Results Concerning Surface Thermocouple Perturbation Effects

The purpose of the Power Burst Facility Loss of Fluid Test (PBF LOFT) Lead Rod (LLR) Test program was to provide experimental data to characterize the mechanical behavior of LOFT type nuclear fuel rods under loss of coolant accident (LOCA) conditions, simulating the test conditions expected for the LOFT Power Ascension (L2) Test series. Although the LLR tests were not explicitly designed to evaluate cladding surface thermocouple perturbation effects, comparison of the Linear Variable Differential Transformer (LVDT) data for rods instrumented with and without cladding thermocouples provided pertinent information concerning the effects of cladding thermocouples on the time to DNB and time to quench data. Documentation and review of this data is presented in the following report. It will be shown that most of the LLR data indicate that the cladding surface thermocouples did not enhance the rewetting characteristics of the rods they are attached to, even though other evidence shows that the surface clad thermocouples did quench early. Finally, in order to accurately interpret and understand the limitations of the LVDT instrumentation, upon which thermocouple perturbation effects were evaluated, an analysis of the LVDT data as well as a review of the atypical response events that occurred during the …
Date: February 8, 1980
Creator: Carboneau, M. L. & Tolman, E. L.
System: The UNT Digital Library
Modeling of beam focusing and kink instability for colliding relativistic electron and positron beams (open access)

Modeling of beam focusing and kink instability for colliding relativistic electron and positron beams

A simulation code has been developed and exercised to study the time evolution and resultant liminosity of intersecting pulses of electrons and positrons. Under the extreme conditions of high current and small radius recently proposed for the SLAC facility, the pulses mutually pinch to a smaller mean radius than that achieved by free flight alone. The effective luminosity is enhanced by a factor of approx. 3 in the best case, corresponding to zero initial emittance and pulse length equal 1/4 the mean betatron wavelength. Gaussian profiles in the longitudinal and transverse coordinates are preferred over flat profiles in order to minimize disruptive oscillations in radius which reduce luminosity. A second potential source of disruption is the kink instability. This is always present to some degree during the interaction of opposed pulses. However, the maximum growth rate is only one half the angular betatron frequency and therefore mode growth is limited to a very low level if the pulses are short compared with a betatron wavelength.
Date: February 8, 1980
Creator: Fawley, W. M. & Lee, E. P.
System: The UNT Digital Library
Total pion cross section measurements. Annual progress report, January 1, 1979-December 31, 1979 (open access)

Total pion cross section measurements. Annual progress report, January 1, 1979-December 31, 1979

The principal effort has been devoted to the data analysis for the pion-nucleus total cross section experiment. Forward scattering amplitudes have been obtained for ..pi..+- mesons on Al, /sup 40/Ca, Cu, Sn, Ho, and Pb. These results are given. Work is continuing on the data reduction for the remaining targets.
Date: February 8, 1980
Creator: Jakobson, M. J. & Jeppesen, R. H.
System: The UNT Digital Library
Demonstration of energy conservation for multi-deck board dryers. Phase I. Final report (open access)

Demonstration of energy conservation for multi-deck board dryers. Phase I. Final report

A study was made to determine the feasibility of recover and reuse of low level heat from the exhausts of multi-deck dryers used to dry boards in the building materials industry. There are approximately 1000 dryers of this type in the USA, with no heat recovery equipment. These dryers are used in the manufacture of: roof insulation board, ceiling tile and panel stock, wood fiber sheathing, gypsum board, and veneer plywood. Pilot scale tests and analyses show that heat recovery designs utilizing several types of heat exchange equipment are feasible. These include the following: indirect contact air-to-air heat exchangers for preheating combustion air for the dryer furnaces; direct contact air-to-water heat exchangers using water sprays to heat process water; and indirect contact air-to-liquid heat exchangers to heat recirculating liquid in a plant building heating system. The systems recommended for design and installation at the Rockdale plant include all three of the types of heat exchangers. The preliminary estimate for the installed cost for these systems at the Rockdale plant is $565,000 (1979 dllars). Annual heat recovery of 186,000 million Btu is projected with a value of $545,000 using gas costs of $3.00 per million Btu. Payback based on a discounted …
Date: February 8, 1980
Creator: unknown
System: The UNT Digital Library