It has been known for a hundred years that formaldehyde polymerizes to carbohydrate substances in alkaline media. Although the reaction has long attracted much attention, only recently has a detailed qualitative analysis of the products been carried out by chromatographic methods. We have started to re-examine this reaction by combining chromatography with radioactive tracer techniques in the hope of refining the quantitative aspects of the analysis. Our particular interest has been to develop methods for determining the relative proportions of ribose and ribulose in the mixtures of sugars formed in basic media, as well as under other polymerizing conditions. The finding of large amounts of these sugars might help to explain the occurrence of ribose as the only basic sugar in the fundamental replicating molecules--the nucleic acids. Formaldehyde is thought to have been present in the primitive reducing atmosphere which existed before life first appeared. The ribonucleic acids must have appeared in the constitution of reproducing systems at a very early stage in the development of living organisms. In this study, the polymerizations of formaldehyde were carried out in calcium hydroxide suspensions at 40{sup o}. Aliquots of the reaction mixtures were withdrawn at after various time intervals and the alkali …

In order to evaluate entry into the atmosphere of an oblate (equatorial bulge) earth a standard atmosphere was used in conjunction with the standard rotating oblate spheroid. The density variation encountered in any one polar orbit around the earth will vary by about a factor of ten, due to oblateness. Therefore, the important effects on the re-entry trajectory are atmospheric density and oblateness of the earth. The SNAP configuration burn up characteristics will differ considerably between the steep (6/sup 0/) entry of the NASA Scout test and the orbital decay trajectory. However, the test can verify heat transfer rates on the actual configuration, and by proper calculation of material response, the actual decay breakup prediction can be improved.

In recent months, several process tubes installed during 1961 have been removed and examined out-of-pile in connection with Tube Corrosion Monitor Studies.1 Most of the tubes were believed to be uniform-wall .080in.-nominal-rib-height tubes. The ex-reactor dimensional measurements obtained near the inlet flange showed,that the tubes did not have uniform walls or .08011 nominal rib heights. Subsequently, dimensional measurements were obtained on approximately 200 new process tubes in an effort to determine the extent of dimensional variations in new process tubes as received from the vendors. The effects of the variations on tube corrosion and tube life are discussed in this report.

Localized cladding instability or necking has resulted in failures of the Zr-2 cladding of rod cluster and tubular fuel elements and fuel rods in NaK filled capsules. The cause of this non-uniform cladding strain is thought to be a combination of the effects of irradiation and nonuniform cladding thickness. To determine the influence of these two factors and that of temperature on the susceptibility to failure, and to obtain data related to cladding thickness tolerances for the NPR fuel elements an irradiation experiment was designed. This experiment consisted of eighteen capsules each containing three Zr-2 clad uranium rods. Cladding thickness variations of up to 25 percent were introduced in the cladding by machining ``grooves`` longitudinally on the outer surface. The temperatures of the cladding were established by the thickness of the capsule wall. These capsules, charged in DR Reactor in October 1961, were prematurely discharged after five days irradiation because of a rupture. The cause of the rupture was established to be overheating and accelerated corrosion of the Zr-2 capsule body as a result of inadequate coolant to the capsule surface.

The fuel element for the test described in this report has been designed to extend the total exposure capability of metallic uranium fuel by altering the type of cladding deformations produced by uranium swelling. In a tabular fuel element of cylindrical geometry, irradiation-induced uranium swelling can cause splitting of the outer clad or buckling of the inner clad. With a fluted outer surface on a cylindrical element, a large amount of swelling may be accommodated by bending of the exterior cladding without the tensile strains which produce localized necking and failure. In addition, the fluted shape, by reducing the restraint on the fuel may direct the volume increases to the outer surface and decrease the likelihood of inner buckling. For this test, the fluted surface concept has been adapted to a tubular element that nominally fulfills the requirements for N-reactor fuel. It is desired to observe the performance of an element with this geometry at an exposure that will produce about 5 percent swelling. It is requested., therefore, that GEH 10-67 and GEH 10-68 be irradiated to an exposure of about 3000 MWD/T in the 6{times}6 M-3 Loop of the ETR.

This report summarizes the results obtained in the experimental measurement of the reactor heat extracted by the coolant during two different scrams of the DR Reactor. These tests were conducted with the reactor flow carefully controlled to establish different reactor coolant temperatures following the scram. During normal reactor scrams, which have been used in the past to measure the reactor heat output, a high coolant flow was maintained. Consequently, the coolant outlet temperature dropped very quickly from an operating value of 90 to 95 C down to 20 to 30 C following the scram. Under emergency conditions, however, with only the last ditch emergency flow available, the coolant outlet temperature could remain as high as 80 to 90 C. This condition could prevail because of the small amount of last ditch flow available, and could last for 5 to as long as 70 minutes after the reactor scram.