MATERIALS TESTING REACTOR-ENGINEERING TEST REACTOR TECHNICAL BRANCHES QUARTERLY REPORT, JANUARY 1-MARCH 31, 1961

Technical Report · Fri Jun 30 00:00:00 EDT 1961

DOI:https://doi.org/10.2172/4843202· OSTI ID:4843202

Large values of reactivity encountered in ETRC measurements of ETR core loadings ( approximately 10% DELTA k/k) can be more accurately predicted as a result of the development of a continuous function equation from distributed Poison equations. The behavior of air pulsers for the Idaho Chemical Processing Plant was studied by an improved analog computer which attempts to handle non- linearities in the system. Fuel and boron content were calculated for replacement of ARMF sub-assemblies. Preliminary measurements indicated no serious error from the use of boron in the RMF as a standard of neutron absorption. MUFT-R cross section libraries are now available for some 25 elements. Tubular thorium slug permissible irradiation flux levels were calculated. Calculations were made of the optimum enrichment of spiked thorium samples to be irradiated in testing a breeder concept. In connection with the use of nickel as a fast flux monitor, it was discovered that the 9.1-hr isomer of Co/sup 58/ has a thermal cross section of approx equal 170,000 b. Irradiated sample fuel plates containing UO/sub 2/ dispersed in Al showed good dimensional stability, but revealed reaction zones around fuel particles. Revised estimates show EGCR fuel sample burnup under ETR irradiation to be 30% less than previously estimated: irradiations of remaining samples will be extended to compensate. Total neutron cross section data were determined for Pa/sup 231/ from 0.015 to 2000 ev, for Pa/sup 241/ from 0.02 to 2000 ev, and for a combination of Au/sup 198/ and Au/sup 199/ from 0.01 to 0.4 ev. The scattering cross section of U/sup 233/ from 2 to 20 ev was determined. Investigation of the ratio of asymmetric to symmetric fission of U/sup 235/ as a function of neutron energy was continued. The yield ratios of two isomeric pairs (Ag/sup 110/ -- Ag/sup 110//sup m/ and Ir/ sup 192/ -- Ir/sup 1/< s9>s/sup 2m/) formed by neutron activation were determined and the thermal neutron cross sections for activation of iridium isotopes were measured. The energies of two low abundance gamma rays in 40.6-d Pm/sup 148/ were determined. Data on the inelastic scattering of slow neutrons by methane, Santowax-R, terphenyls, and propane were reduced to curves. Differential scattering cross sections sigma (E/sub 0/, epsilon , theta ) with respect to energy change epsilon and scattering angle theta were calculated for several incident neutron energies E/sub 0/ using the Kreiger-Nelkin approximation. Low frequency vibrations in olefinic hydrocarbons were calculated by treating the CH/ sub 2/ and CH groups as rigid units capable only of translational and rotational motions. Observation was made of the growth of the Y/sup 90/ ground state activity from the decay of an activity with a half life of approximately 3.14 hr which provides further evidence that the latter activity arises from the decay of an isomeric level in Y/sup 90/. Branching ratios for alpha decay of Pu and Pu were calculated. A spin of 4+ was assigned as probable to the 1.57Mev state in Mo/sup 94/. Spin and parity assignments were made for all of the Sm/sup 148/ states excited in the decay of 41-d Pm/sup 148/. Average cross sections for a fission neutron spectrum were measured for the reaction K/sup 41/(n, gamma )K/sup 42/ (9.5 plus or minus 0.9 mb) Na/sup 23/(n, gamma )Na/sup 24/ (0.53 plus or minus 0.05 mb), and K/sup 41/(n,p) Ar/sup 41/ (1.2 plus or minus 0.1 mb). A number of programs for the IBM-650 were completed and placed in the program library for general use. These include a double precision normal equation generator, a predictor-corrector method for differential equations, and a program for the numerical inversion of Laplace transforms. A successful procedure for estimating the optimum overrelaxation constant was added to the steady state temperature program, TDTP. A computer program to automate the design of flat plate fuel elements was written. (auth)

• Research Organization: Phillips Petroleum Co. Atomic Energy Div., Idaho Falls, Idaho
• DOE Contract Number: AT(10-1)-205
• NSA Number: NSA-15-028861
• OSTI ID: 4843202
• Report Number(s): IDO-16695
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-61
• Country of Publication: United States
• Language: English

Related Subjects

GENERAL AND MISCELLANEOUS
ABSORPTION
ACTIVATION
AIR
ALKENES
ALPHA DECAY
ALUMINUM
ANALOG SYSTEMS
ARGON 41
BORON
BRANCHING RATIO
BREEDING
BURNUP
CHEMICAL REACTIONS
COBALT 58
COMPUTERS
CONFIGURATION
CROSS SECTIONS
DECAY
DIFFERENTIAL EQUATIONS
DIGITAL SYSTEMS
DISPERSIONS
EFFICIENCY
EGCR
ENERGY
ENERGY LEVELS
ENRICHMENT
EPITHERMAL NEUTRONS
ERRORS
ETR
EXCITATION
FISSION
FUEL ELEMENTS
FUELS
GAMMA RADIATION
GENERATORS
GOLD 198
GOLD 199
IBM 650
IRIDIUM 192
IRIDIUM ISOTOPES
IRRADIATION
ISOMERS
KRIEGER-NELKIN THEORY
LAPLACE TRANSFORM
MATRICES
MEASURED VALUES
METHANE
METHYLENE RADICALS
METHYLIDENE RADICALS
MOLYBDENUM 94
MOTION
MUF