The development of nuclear reactors and other nuclear particle sources has given the analyst a new analysis method which can be successfully applied to the determination of microgram and submicrogram quantities of many elements. Known as "radioactivation analysis", this method is one in which an "activation" by some type of nuclear reaction is used to produce a radioactive isotope of the element to be determined. Since this radioisotope decays with its own characteristic radiations and half-life, it is possible to make radioactivation analysis a very specific analysis. Chemical separations of the radioisotope are employed whenever necessary and its radioactivity measured by some type of radiation counter.

An analog simulation is made of the HRP in-pile slurry loop in the LITR. The radiolytic gas pressure in the pressurizer is determined. This pressure is a result of the generation of radiolytic gas in the loop core. A graphical result is obtained showing the effect of catalyst activity and pressurizer flow rate on the pressure rise from radiolytic gas. The thermal behavior of the system is studied, and the response to various controller settings is predicted. Controller settings very near optimum for the actual process were recommended from the analog study,

On 3/14/60 the Applied Physics Corporation was awarded a subcontract for the design and development of a high-temperature high-pressure spectrophotometer system based on the Cary Model 14pm Spectrophotometer insofar as possible, and consistent with our specifications, No. CTD-2, December 16, 1959.

An experiment was performed at the ORR in order to find a good fission chamber location. Two locations on the pool side of the reactor tank were explored with a one inch diameter fission chamber. The thermal neutron flux attention was found to vary nearly exponentially with distance, and no shadowing effect could be seen during a reactor startup. The fission products high gamma flux could be discriminated without difficulties. Both positions seem to be adequate to locate a reactor control fission channel.

A stimulation study of the deign as of June 1960 of the gas-cooled ORR Loop No. 1 was made using the ORNL analog computer. The proposed method of temperature control is evaluated, and the dynamic behavior of the loop for accidents and component failures is presented in graphical form.

Equipoise-2, a two-dimensional, two-group neutron-diffusion code in R-Z geometry, has been programmed for the IBM-7090 computer. This code was designed to permit the running of large numbers of cases without requiring excessive machine time. Typical running times are of the order of one to three minutes per case for a 1000-point problems. The maximum number of mesh points that can be used is 1444.

Simon (1960) has given a general steady state theory of plasma accumulation (without energy losses) in an OGRA device. Such a device is fed by injection of energetic molecular ions which dissociate to produce trapped protons. Initial trapping is achieved by dissociation in the background gas. Such a device is usually characterized by a critical input current of critical plasma density (a function of input current) above which plasma density builds up to a value limited by Coulomb-scattering losses. For a regime of operation of current interest at Oak Ridge National Laboratory (600-kev hydrogen molecular ion injection and dissociation, highly efficient ion-pumping action of the trapped plasma), extremely simple approximate formulas have been derived which describe with a fair degree of accuracy the critical current of density for plasma build-up.

This report is a working document of the UB AEC Nuclear Cross Sections Advisory Group and is issued about twice a year for the purpose of stimulating important cross section measurements. The requests listed in this report have originated from various Atomic Energy Commission contractors, the Advisory Committee on Reactor Physics, and the Nuclear Cross Sections Advisory Group. The distribution is limited to members of the US Nuclear Cross Sections Advisory Group (NCSAG), the US Advisory Committee on Reactor Physics (ACRP), the Tripartite Nuclear Cross Sections Committee (TNCC), the European-American Nuclear Data Committee (EANDC), to US AEC off-site contractors, and to the requestors and measurers of the cross sections listed in this report. The contents of this document are not to be republished in part or in full without special permission of the chairman of the NCSAG, The unpublished data which appear in this report must not be quoted in publications without permission of the experimenter.

A short-term study was made to investigate the removal of radioiodine vapor from air-steam mixtures as could occur immediately following a nuclear incident in a pressurized water reactor. Activated charcoal traps, designed to simulate a small section of a commercial charcoal canister, were tested at gas velocities of 23.9 to 74.9 ft/min over the temperature range of 75 to 118°C. The iodine removal efficiency was found to range from 99.80 to 99.4% with an average of 99.9%. One test performed at a temperature of 105°C and with gas velocity of 290 ft/min indicated that the iodine removal efficiency was reduced to 99.54%. Activated charcoal exhibits a high efficiency for iodine vapor removal under these test conditions and appears suitable for application in the decontamination of air-steam mixtures.

The attached paper is a translation of a rough draft of the paper, "Operating Experience of the APS-1", presented by M. Minashin in Russian at the IAEA Conference on Small and Medium Power Reactors, Vienna, Austria, September 5-9, 1960.

The hazard of Sr^90 arises in part from its fixation by phosphates in the skeletal system. It is natural then to consider compounds and minerals associated with the phosphate anion for applications in waste disposal. Calcium phosphate floc formation is widely used as a method for removing strontium from contaminated water. Also, calcerous soils are said to be effective for removing strontium from low-level wasters containing dissolved phosphates. It is suggested that one the mechanisms involved in strontium removal is the formation of calcium phosphate (apatite), with strontium substituting isomorphously.

The computer program which performs spatial reconstruction of events photographed in a bubble chamber is required to eliminate human and digitizer errors. It recognizes and corrects for single nuclear scatterings in the presence of multiple Coulomb scatterings. Momentum components are determined and kinematic constraints are applied. Measured parameters are performed into special reference frames and quantities of physical interest are calculated. Results are stored in a tape file containing all events of one reaction type.

A modification of the Bridgeman anvils is described. This modification permits studies to be made to a load of 400 kbars, about twice that previously available.

The relative yield of neutral photopions from various elements was determined as a function of the quantum limit energy of the Berkeley synchrotron. Single decay photons from neutral pions were observed at 45, 90, and 135 deg to the incident bremsstrahlung in the laboratory system. Mean free paths for neutral pions in nuclear matter were obtained, an optical model prediction of the photopion yields based upon pion-nucleus scattering data was confirmed, and the presence of coherent pion production in the forward direction was detected.

"An algorithm for the generation of feasible schedules and the computation of the completion times of the job operations of feasible schedule is presented. Using this algorithm, the distribution of schedule times over the set of feasible schedule—or a subset of feasible schedules—was determined for technological orderings that could occur in a general machine shop. These distributions are found to be approximately normal. Biasing techniques corresponding to “first come first serve,” random choice of jobs ready at each machine and combinations of these two extremes were used to compute distributions of schedule times."

"The loss of particles through a cusp of a particular containment geometry utilizing cusped magnetic field lies is considered. A velocity space loss criterion analogous to the loss cone in the mirror machine is derived. The effect of a uniform longitudinal magnetic field perpendicular to the containing field is considered and a loss criterion is derived. The effect of the longitudinal field is to decrease cusp losses.

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"In our original proposal it was pointed out that we had obtained, b the successive treatment of adrenochrome with mineral acid and thiosemicarbazide, a black material which proved to be effective in preventing vascular damage cause by snake venom, radiation and thermal burns. Since the effectiveness of this preparation varied widely with different samples it was suspected that the product did not have a uniform composition. As a results of the inability of effect a separation or purification of the black product we decided to try some pure compounds related to adrenochrome. Some results obtained were reported in our proposal to renew contract AT(301\-1)-2242. Other results will be reported in the body of this report."

"This report describes two experiments performed in an effort to supply evidence for the universality of the V-A theory in weak interactions and for the law of conservation of leptons. In this first part the production rate of B to the 12th by the absorption of negative mu mesons in carbon was measured. From the amplitudes of the muon decay curve and the boron decay curve the rate was calculated to be (5.8 plus or minus 1.3) x 10 to the 3rd sec -1, in agreement with the hypothesis of a universal V_A theory. In the second part an attempt was made to measure the helicity of negative mu mesons by stopping longitudinally polarized muons in a carbon target and observing the electron asymmetry in the β-decay of the spin-1 B to the 12th. The results of this part were inconclusive, a consequence attributed to a short boron thermal relaxation time."

"With careful attention to details, tritium assays of satisfactory accuracy have been achieved on low activity standard samples by dry combustion and liquid scintillations counting of the product water.This method is faster, more accurate and dependable than the zinc fusion-ion chamber method fro low level tritium assays. At 380 degrees C, tritium loses from hydrocarbon tracers by isotopic exchange is significant and must be corrected for in tracer measurements at this elevated temperature."

"A new phenomenon which can, under certain circumstances, account for anomalous magnetic and spectral behavior of planar nickel(II) complexes has been discovered. This is a molecular association of the solute molecules in solvents of low coordinating power. It is shown that the magnetic moment and spectrum of bis(2.6-dimethyl1-3,5-heptanediono)nickel(II), Ni(DIBM)z, dissolved in toluene, are dependent upon both temperature and concentration.

"Additional mixtures of polymers and multi-unsaturated monomers have been prepared, irradiated and the gel content determined. The gel content determination of crosslinked polyolefins has been investigated in detail. The multi-unsaturated monomers used and radiation conditions applied up to this time have not given significant gel contents for polypropylene. the polypropylene resin used has been characterized by differential extraction."

An experiment has been performed using nuclear emulsions to measure the neutron flux and energy spectrum from a thick uranium target bombarded by 18-Mev electrons. The total integrated flux of 3.6 x 10(-4) neutrons/electron found here is considerably lower than the figure reported by other investigators. We attribute this discrepancy primarily to a wandering of the electron beam. The neutron spectrum should be unaffected. In addition to the expected peak at 1 Mev the energy spectrum shows a secondary peak at about 5 Mev. The shape of the experimental spectrum excluding this secondary peak, is fitted theoretically by a combination of the "evaporative" and "resonance direct" effects.

A title list of 119 reports published between 1952 to mid 1960 is given.