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Fatigue-crack propagation behavior of Inconel 718

Description: The techniques of linear-elastic fracture mechanics were used to characterize the effect of several variables (temperature, environment, cyclic frequency, stress ratio, and heat-treatment variations) upon the fatigue-crack growth behavior of Inconel 718 base metal and weldments. Relevant crack growth data on this alloy from other laboratories is also presented. (33 fig, 39 references) (auth)
Date: September 1, 1975
Creator: James, L.A.
Partner: UNT Libraries Government Documents Department

Evaluation of the effects of an integral fin spacer design on predicted fuel pin and subassembly duct performance

Description: The effect of an integrally finned fuel pin cladding design on LMFBR subassembly performance has been evaluated. Effects on thermal/hydraulics, fuel pin lifetime and duct lifetime are considered. Results are presented for 19, 61 and 217 pin subassemblies.
Date: January 1, 1976
Creator: Sutherland, W.H.; Cantley, D.A.; McCurry, D.C. & Parker, M.B.
Partner: UNT Libraries Government Documents Department

Hypothetical core disruptive accident

Description: The hypothetical core disruptive accident in an LMFBR is discussed under the following main headings: reactor dynamics; mechanical consequences; and post- accident heat removal. 79 references. (DCC)
Date: July 1, 1975
Creator: Simpson, D.E.
Partner: UNT Libraries Government Documents Department

Effect of temperature on the fatigue-crack propagation behavior of A-286 steel

Description: The techniques of linear-elastic fracture mechanics were used to characterize the effect of temperature upon the fatigue-crack growth behavior of A-286 steel in an air environment over the temperature range of 75--1000$sup 0$F. In general, the fatigue-crack growth rate increased with increasing temperature. Two material forms were tested: 0.5 inch-thick strip material and 1.5 inch- diameter bar. Two different crack orientations were tested in each product form. In general, no significant differences in crack growth behavior were noted between product forms nor between the different crack orientations. (auth)
Date: April 30, 1976
Creator: James, L.A.
Partner: UNT Libraries Government Documents Department

Development of ultrasonic methods for examining stainless steel welds. Interim progress report

Description: Spurious ultrasonic (UT) signals obtained during the examination of austenitic stainless steel welds in LMFBR components have emphasized the need to develop more effective UT methods to supplement the examination processes presently employed during fabrication, and for use during subsequent in-service inspection of LMFBR plants. This interim report documents the first year's effort on a program that was designed to investigate this problem and develop viable solutions. Sixty-eight weld samples were acquired, cataloged, and subjected to a series of ultrasonic, radiographic, and metallographic examination procedures. It was determined that although spurious UT noise signals could usually be associated with major dendritic grain growth patterns, the existence and magnitude of some of the observed noise signals could not be explained simply on the basis of dendritic microstructure. The results obtained during application of a series of ultrasonic and radiographic characterization procedures are included, in addition to photomicrographs and photomicrographic montages taken in the vicinity of numerous sites which produced ultrasonic noise signals of various amplitudes. A concurrent investigation was conducted to evaluate the performance of conventional ultrasonic examination procedures. These results are compared with the laboratory investigation results, and a brief outline of future work planned under this program is presented. (auth)
Date: November 1, 1975
Creator: Peterson, R.O.; Spanner, J.C. & Mech, S.J.
Partner: UNT Libraries Government Documents Department

EBR-II 75D, high power dosimetry test

Description: Preliminary analysis has been completed for twelve midplane sets irradiated in the EBR-II Run 75D high power dosimetry test. Results indicate changes that have occurred in the EBR-II core environment since previous dosimetry test measurements made before the substitution of the stainless steel reflector for the depleted uranium blanket. Large flux variations were also noted outside the core depending on the composition (fuel vs. structural) of neighboring core subassemblies. (auth)
Date: December 1, 1975
Creator: Lippincott, E.P.; Ulseth, J.A.; Kellogg, L.S.; Davis, A.I. & McElroy, W.N.
Partner: UNT Libraries Government Documents Department

Feasibility of evaluating the integrity of FTR duct to end fixture welds using acoustic emission monitoring

Description: A method of applying real-time acoustic emission (AE) source location to evaluate the integrity of duct-to-end fixture welds was developed and evaluated using the HEDL R8-4 AE monitor coupled with a PDP-8e minicomputer. Operational software was developed to control the system's data acquisition, storage, and display functions. Performance was evaluated on the basis of comparisons between AE source location data and subsequent destructive examination of six duct-to- transition ring qualification welds. Ten separate discontinuities seen in the metallography performed at 35 locations along these welds correlated with the averaged acoustic emission activity revealed by the AE source location maps. This relationship is not presently considered to be usable as a system calibration method however, because of the limited range of discontinuity lengths (from 0.0003 to 0.004 in. long) that were correlated. The presence of six other discontinuities, found in regions showing low levels of emission activity, indicated that significant stress risers can go undetected under the conditions investigated. (auth)
Date: November 1, 1975
Creator: Trantow, R.L.
Partner: UNT Libraries Government Documents Department

Design and performance of a microwave strain measuring system for materials tests

Description: Excellent sensitivity and accuracy in the measurement of deformation occurring in materials tests have been achieved with a newly developed microwave frequency sensor and instrumentation system with possible application for strain tests inside nuclear reactors. The strain sensor comprises a microwave cavity resonating in the circular TE 113 and TM 110 modes. Detection of axial strain occurs due to the changes of resonant frequency incurred by cavity length changes. Axial strain sensitivity for the TE 113 mode was 6 x 10$sup -6$ per MHz, whereas radial dimensions of the cavity were related to frequency of the TM 110 mode. Aperture coupling of the cavity to the end wall of K/sub a/ band waveguide provided signal excitation of the two monitored modes. Phase locked frequency stability enabled digital count/display of resonant frequencies to within 70 kHz at 35 GHz. Room temperature tension test results demonstrate a strain measuring sensitivity (+- 1 x 10$sup -6$) and accuracy (+ -1 percent of the measured value) equivalent to those of electrical resistance strain gages. The system yields accurate measurements of elastic strains as well as small departures from elastic response and hysteresis behavior during unloading and reloading. Creep test results confirm that measurement sensitivity and accuracy are retained in elevated temperature tests. Strain response on loading, subsequent creep deformation and creep recovery after unloading can all be measured in detail. Stability of microwave sensor calibration after exposure for 22 x 10$sup 6$ seconds at temperatures from 728$sup 0$K to 866$sup 0$K is shown to be excellent.
Date: December 1, 1975
Creator: Billeter, T.R. & Blackburn, L.D.
Partner: UNT Libraries Government Documents Department

Feasibility study on infrared electro-thermal NDE of stainless steel

Description: Electro-thermal examination, a branch of thermal testing (TT), is a promising method being developed for NDE of stainless steel welds. This report describes the first phase of development; i.e., preliminary demonstration and laboratory evaluation of the method's sensitivity to notches in Type 304 stainless steel plate specimens. It also includes a description of the basic principles, together with a description of the hardware and experimental results showing that electrical discharge machined notches down to 0.16 cm (0.06 in.) long x 0.08 cm (0.03 in.) deep were detected. A qualitative technique for interpreting the test results to determine whether defects are at the surface or deeper within the material is demonstrated. (auth)
Date: November 1, 1975
Creator: Green, D.R. & Hassberger, J.A.
Partner: UNT Libraries Government Documents Department

Compilation of data and descriptions for United States and foreign liquid metal fast breeder reactors

Description: This document is a compilation of design and engineering information pertaining to liquid metal cooled fast breeder reactors which have operated, are operating, or are currently under construction, in the United States and abroad. All data has been taken from publicly available documents, journals, and books. (auth)
Date: August 1, 1975
Creator: Appleby, E.R.
Partner: UNT Libraries Government Documents Department

Some findings from FFTF piping and component design analyses

Description: A number of questions that have been commonly raised during elevated temperature design of FFTF components and pipelines are identified and discussed. Although the questions do not lend themselves to simple answers, some guidance based on analysis findings is given. Based upon the limited data developed, uniaxial stress relaxation data can give a reasonable pattern of structural creep damage as a function of time. However, the creep damage magnitude may be as much as a factor of two too low. Other geometries and/or loading may show much larger variations between the uniaxial and complex hardware creep damage response. (auth)
Date: September 1, 1975
Creator: Severud, L.K.; Weiner, E.O. & Winkel, B.V.
Partner: UNT Libraries Government Documents Department