Report documenting the progress of the Army Gas-Cooled Reactor Systems Program to develop a mobile nuclear power plant for military field operation.

Nucleon-meson cascade calculations were carried out and the dose as a function of depth was obtained for an 800-Mev proton beam incident on a shield. The physical properties used for the shielding medium are only a rough approximation to the properties of any particular medium. Muon, neutron, pion, and proton dose rates and fluxes are listed. (auth)

In a previous report nucleon-meson cascade calculations were carried out for several cases of interest in the design of the transverse shield for the proposed 45-Bev linear electron accelerator at Starford University. In this report results are given for several additional cases. Muon, neutron, pion, and proton intensities as function of energy and distance for varying angles are given. Corresponding doses are also included. (D.C.W.)

S>Critical studies of two fast reactor cores are described: one contains uranium and steel; the other contains uranium, steel, and sodium. Experimental results are given for fission ratio, central and edge reactivity coefficients, fuel bunching, average prompt neutron lifetime, and distributed worth measurements. (auth)

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Previous investigations that the pancreas is a radioresistant organ. Ivy in 1924 noted the presence of a fibrotic atrophic pancreas in a dog which had received one erythema dose to the epigastrium. Fisher in 1923 reported that four to five erythema doses delivered in a single application caused complete disappearance of the irradiated pancreatic remnant in about two months. These dogs died because of uncontrolled diabetes. One dog that received four erythema doses (possibly 200 r) was sacrificed after five months. At autopsy the irradiated pancreas had disappeared, but 275 mgm of regenerated pancreas were found at the base of the main duct and 100 mgm at the base of the accessory duct. Leven in 1933 implanted radon seeds into the pancreas. Dosages varied from 528 to 1584 millicurie hours. At postmorten the pancreas surrounding the seeds demonstrated fibrous atropy and foci of necrosis. The islets appeared normal but were relatively larger in size. Rauch in 1952 reported that dogs given 200 r in air over the pancreas on alternate days until a total of 1600 r was received failed to show any histological changes after two months. Lushbaugh and Spalding and Lushbaugh reported that over 1500 r of whole-body …

An isochronal differential-type microcalorimeter has been designed and constructed. As a result of its simple design it is very easy to handle the samples and assemble the calorimeter. Important to the operation of the calorimeter is a program, also working on the differential principle, that provides linear temperature rise of the samples. This calorimeter is used to measure very small energy releases such as those found in precipitation, stored energy, etc. It is demonstrated that the calorimeter is easily capable of measuring 0.0005 cal with a probable error of the order of 1% to 2%.

A kinetic study of the exchange of normal and radioactive bromine in graphite-bromine lamellar compounds has been made at temperatures of 30° to 50°C. Natural and synthetic graphite powders were investigated. Two alternative mechanisms for the exchange, volume diffusion and surface exchange, were considered. The data were in better agreement with the diffusion mechanism. Diffusion coefficients of 10 -9 to 10 -8 cm2/sec and an activation energy of 11 to 14 kcal/mole were calculated for the natural graphite powders. The diffusion coefficients increased with increasing bromine content. Reversibly absorbed bromine exchanged more rapidly than irreversibly absorbed bromine.

The Large Component Test Loop is a facility for ASCR providing experimental capacity for subjecting large components, such as moderator assemblies and control rods, to thermal gradients and transients at varying rates of sodium flow to simulate reactor operating conditions. Two separate loops are used for heating and cooling the sodium as the testing is performed. The 3-inch pump loop, modified to operate at 1200 deg F, was operated at a flow of 130 gpm and a head of 25 feet. The 6-inch pump loop, limited to 1000 deg F operation by materials of construction, was operated at a flow of 2000 gpm and head of 65 feet. The rest of the facility has operated satisfactorily at 1200 deg F. (auth)

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For an experiment to measure the magnetic moment of the Λ hyperon, it was necessary to extract the external beam of the Cosmotron with maximum efficiency and with minimum time duration. To accomplish this end, the standard external beam of the machine was supplemented with the Rapid Beam Ejector. It was found that, unfortunately, the ejection efficiency of the beam was less than normal when the RBE was used. Measurements of the ejection efficiency were made by irradiating polyethylene foils at the second focus of Beam 1 with 3 BeV protons. The external beam was tuned up and optimized in a standard manner. It was found that the ratio of the number of protons ejected with the RBE to the number ejected without the RBE was 0.3 in one run and 0.22 in another try. It was also observed that the RBE did not shift the position of the external proton beam focus to within ± 1/8 in.

This paper will first note briefly the place and status of radiobiotopical investigations with fast neutrons. The monoenergetic (fast) neutron technique employed at this laboratory will be then described and results of studies with various criteria-of-effect in the mouse will be reviewed. Finally, certain general patterns of response for these systems will be pointed out as functions of neutron energy.

The differential cross sections for elastic scattering of 14-Mev neutrons from nitrogen and oxygen were measured in the angular range from 17 to 140 deg , using liquid targets and annular ring geometry. Inelastic scattering to the 2.31 and 3.95-Mev levels in N/sup 14/ and to the levels near 6 and 7 Mev in O/sup 16/ was investigated over a more restricted angular range. The 2.31-Mev level in N/sup 14/ was not excited appreciably, in disagreement with previously reported results. For both elements, the elastic scattering cross sections (determined to an accuracy of 10%) were found to be appreciably higher than the optical model predictions by Rjorklund and Fernbach for scatterirg angles larger than 70 deg . The inelastic cross sections measured are, within experimental accuracy, the same as the corresponding (p,p') cross sections. (auth)

The enzymolysis by α-chymotrypsin of the substrates, N-acetyl-L-tryptophane ethyl ester and N-acetyl-L-tyrosine ethyl ester, was followed by means of fluorescence whose intensity increased fourfold and threefold per mole respectively as substrate was transformed into amino acid. The assay by fluorescence was several orders of magnitude more sensitive than the assay by differential absorption spectra of these substances and was in agreement with it in those concentration regions where both methods overlap. To maintain linearity between concentration and fluorescence intensity, the concentration of substrate should be no greater than 10-4 M/1. In such solutions the rate of esterolysis could be followed with the enzyme at 10-11 M/1.

About 298,000 OIIIN aluminum components were received from Harvey for evaluation after major steps were take in the vendor`s plant to upgrade product quality. This material met HAPO specifications and was comparable to Alcoa control components. Finished fuel elements (non-bumper and bumper) canned in the test and control components are tabulated by uranium core type and canning month. Non-destructive and destructive test data did not show any differences in clad fuel elements attributable to component quality. Irradiation status of non-bumper and bumper fuel elements clad in Harvey improved components as of Dec. 31, 1962, is tabulated, as is a summary of ruptures. It was recommended that Harvey Aluminum Co. be allowed to bit competitively on all future Al component orders except for the KVN and KVE component models.

Information concerning the corrosive effects of water in power reactor moderator-coolant systems is presented. The information is based on investigations reported in the unclassified literature believed to be fairly complete to 1959, but less complete since then. The material is presented in sections on water decomposition, water chemistry, materials corrosion, corrosion product deposits, and radioactivity. It is noted that the report is presented as a part of a continuing program in development of less expensive materials for use in reactors. (J.R.D.)

The Doppler coefficient in thorium dispersed in graphite was measured in a reactor spectrum developed in the HTGR critical assembly, using a reactivity technique that compares the reactivity of a single cold element and a single hot element heated to 700 deg K. The considerable correction due to the small perturbation in neutron temperature resulting from the heating has been experimentally determined by auxiliary measurements. An activation technique has been used to check the results. In this activation technique, the thermal-base effect has also been experimentally subtracted by measuring the 1/v component of the captures at each temperature in vanadium. Measurements of the Doppler coefficient obtained by these two different techniques agree to within 10%. This agreement, demonstrated by applying both techniques for the first time in the same laboratory, shows that the previously reported spread of results and apparent disagreement between results of these two techniques are avoidable. The average Doppler coefficient for the temperature interval from 300 to 700 deg K, for a carbon-to-thorium ratio of about 50 in the thorium-bearing region, was measured to be 3.6 x 10/sup -4// deg C to within about 10% uncertainty. The measured results are in satisfactory agreement with calculated values. (auth)

Report concerning the protection offered against radioactive fallout offered by two types of structures at the Nevada Test Site. Differences between above ground and underground structures are measured and compared to data taken from actual fallout conditions.

The objectives of this production test are to confirm the KVNS fuel element design, determine the effect of support height on annulus coolant temperature distribution (R Value), evaluate the effect of eccentricity on KVNS fuel element irradiation behavior.

A half-plant low alum water treatment test began at F Reactor on January 16, 1963 at startup from the scheduled January 3 tube replacement outage. The test, which was prompted by results obtained from a statistical analysis of fuel ledge corrosion attack, will demonstrate whether or not high alum feed is responsible for increasing the frequency of ledge corrosion attack on fuel element surfaces. The effect will be evaluated by comparing visual examination results obtained from normal production fuel irradiated in two different alum treated process waters. This report discusses the results obtained from twenty fuel charges, ten from each side of F Reactor, which were discharged prior to the reduction in alum feed to establish the pre-test corrosion environment.

This study was undertaken to answer questions asked regarding the required rod stroke for control of modified Tory II-C reactors. All problems described were solved with the Angie code and based on Tory-II-C design problems, RZ 501 and RZ 502, representing hot and cold reactors respectively.

It has been known for many years that bone growth may be retarded by relatively large doses of therapeutic radiation. Similar doses of radiation have also shown retarded growth in animals. More recently, reports of studies of Japanese children exposed to the Atomic Bomb Detentions at Hiroshima and Nagasaki and Marshallese children exposed to radiation in the fallout accident of 1954 have indicated some impairment in their growth and development, possibly related to radiation exposure. Since the doses of radiation received by these children were lower than would be expected to produce retardation of bone growth by direct irradiation, it was considered that indirect mechanisms might play a part. This preliminary report summarizes investigations of possible indirect effects of X-irradiation in bone growth in rats.

The diffusion of lithium in aluminum was measured at various temperatures with diffusion couples of aluminum-LiAl. The activation energy, E, is 33.3 kcal/mol, and the diffusion factor, Do, is 4.5 cm{sup2}/sec. (auth)

Tritiated thymidine (H3TDR), a specific precursor of deoxyribonucleic acid (DNA), has proved to be a valuable tool in the study of in vivo cellular kinetics. Various methods of analysis have been used in autoradiographic investigations of proliferative patterns and time parameters in different cell lines.