Reported radioactivity in the Low-Intensity Test Reactor (LITR) water coolant traceable to uranium contamination on the surfaces of the alclad uranium-- aluminum plate-tyne fuel element led to an investigation to determine the sources of uranium contamination on the fuel plate surfaces. Two possible contributors to surface contamination are external sources such as rolling-mill equipment, the most obvious, and diffusion of uranium from the uranium-aluminum alloy fuel into the aluminum cladding. This diffusion is likely because of the 600 deg C heat treatments used in the conventional fabrication process. Uranium determinations based on neutron activation analysis of machined layers from fuel plate surfaces showed that rolling-mill equipment, contaminated with highly enriched uranium, was responsible for transferring as much as 180 ppm U to plate surfaces. By careful practice where cleanliness is emphasized, surface contamination can be reduced to 0.6 ppm U/sup 235/. The residue remaining on the plate surface may be accounted for by diffusion of uranium from the fuel alloy into and through the cladding of the fuel plate. Data obtained from preliminary diffusion studies permitted a good estimate to be made of the diffusion coefficient of uranium into aluminum at 600 deg C: 2.5 x 10/sup -8/ cm//sec. To …

The graphite movement which has occurred at the various reactors has been characterized by two problems: (1) Crooked channels and (2) cracks and miscellaneous voids where pieces of blocks are missing. Of these problems, the cracks and voids have been the most serious in the case of ball drops. Alleviation of the crooked channels can sometimes be accomplished by graphite removal methods such as broaching, but unless some method is found to prevent the balls from entering cracks, the total effect of a ball drop would still be intolerable. Of the two methods of closing the cracks, a paste caulking procedure is anticipated to be less expensive than sleeving, both in terms of cost of the operation and the number of process tube channels which might be lost. If the VSR channel does not require drastic straightening or entry of large tooling, satisfactory caulking can be done without removal of the step plug. ``Poison`` chain may be considered as an alternative to caulking or sleeving for those outer VSR channels where the sole use of balls is for ``total control`` rather than ``speed of control.`` The objectives of this test are (1) to authorize the experimental crack filling of one …

The objective of Production Test IP-725 was to investigate the reaction rate between graphite and carbon dioxide in F Reactor at a temperature 50 C higher than that currently permitted by Process Standards. After approval of the test, the temperature limit was increased from 650 to 700 C. After approximately three weeks of operation with the-higher temperature limit, the reactor was shut down and the graphite oxidation monitor samples which had been inserted for this test were discharged and measured. It is believed that sufficient data have row been obtained from the first phase of the test to warrant investigation at an even higher temperatures. It is therefore the objective of the supplement described in this report to raise the graphite temperature limit at F Reactor by an additional 50 C to a limit of 750 C.

The existing Hanford production reactors are enveloped by a graphite reflector, a cast iron thermal shield, and a biological shield consisting either of laminations of iron and masonite or of high density concrete. Cooling tubes were bonded into grooves in the cast iron thermal shield blocks with lead. As the graphite moderator continues to contract as a function of exposure, it is felt that the bond between the cooling tubes and the top cast iron blocks will be broken since these blocks are supported by the graphite. In the limit, the cooling tubes undoubtedly will pull from the grooves and be suspended between the cast iron and the top biological shield. In this event the effectiveness of the cooling system will be impaired severely, yet it will be necessary to limit the maximum temperature in (and the temperature gradient through) the top biological shield to assure its integrity. The calculations reported herein were made to provide heat generation rates in the shield complex as a function of fringe poison so that temperature distributions could be calculated for various postulated conditions of the cooling system. Thus, it should be possible to estimate the potential for controlling shield temperatures with fringe poison …

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Declassified 28 Aug 1973. W--20 vol% U0/sub 2/ honeycomb structures were successfully made by two fabrication methods. One method involved stacking of individual unsintered hexagonal tubes, followed by isostatic pressing and sintering. The other method formed the unsintered honeycomb as a unit which was then sintered. The sintered structures, eonsisting of a close array of 1-1/2 in. long hexagonal channels, had densities ranging from 94 to >97% of theoretical. In addition to honeycomb fabrication, two methods are described for cladding the interior honeycomb surfaces to prevent U0/sub 2/ loss during high-temperature operation. (7 tables, 32 figures). (auth)

Two simultaneous effects occur during the irradiation of polycrystnlline graphite which account for the observed dimensional instability. The first is a disordering of the crystallites which results in an expansion parallel to the c axis and a contraction parallel to the a axis. This process is highly temperature dependent and at room temperature is the principal effect. The second effect is a nonannealable contraction, which acts primarily in the transverse direction in anisotropic nuclear graphite, and seems to occur primarily in the non-graphitic part of the polycrystalline structure. (auth)

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This two-dimensional photoelastic study was performed as a means of determining what effect a notch at the base of the flanges had on the strength of these parts. These notches were proposed as a means of clamping the shield and reflectors. The objective of this test was to determine the amount of increased stress in the flange and clamp at the required locations.

This report addresses the Bendix TPCV actuator presentation.

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From abstract: "The hydrides of group VB an VB elements, except CH4 and NH3, have been prepared and, except for PbH4 and BiH3, their mass spectra studied. Fragmentation patterns and appearance potentials of the positive ions from these hydrides are reported. The ions have been tested for excess kinetic energy and this energy was found to be negligible. The average M-H bond energies and the ΔHf° obtained from appearance potential data agree well with values obtained by other methods. Evidence is cited for the existence of distibine."

This technical report discusses the synthesis of vic-dioximes, the analysis of vic-dioximes, the structure of vic-dioximes, the structure of metal(II)-vic-dioxime complexes, and analytical applications of this research. The report includes tables and figures that accompany the report's contents and findings.

This technical report discusses processes to study the stability constants and intrinsic solubility of several Nickel(II)-vic-Dioxime complexes.