Measurements obtained during three periods of HRT operations indicated that the xenon poison fraction was approximately 0.010. The technique used was based on mass spectrographic analyses of the stable xenon isotopes in the reactor off-gas stream. Models proposed to explain the measurements show that xenon, which is formed primarily by decay of iodine adsorbed on the pipe walls, is held up on the walls, out of the circulating stream, for an average period of about eight hours. (auth)

Molten fluoride salts, because of their radiation stability and ability to contain both Th and U, offer important advantages as high-temperature fuel solutions for nuclear reactors and as media suitable for nuclear fuel processing. Both applications have stimulated experimental and theoretical studies of the corrosion processes by which molten salt mixtures attack potential reactor materials. Corrosion experiments with fluoride salts which were conducted in support of the Molten-Salt Reactor E xperiment and analytical methods employed to interpret corrosion and masstransfer behavior in this reactor system are discussed. The products of corrosion of metals by fluoride melts are soluble in the molten salt; accordingly passivation is precluded and corrosion depends directly on the thermodynamic driving force of the corrosion reactions. Compatibility of the container metal and molten salt, therefore, demands the selection of salt constituents which are not appreciably reduced by useful structural alloys and the development of container materials whose components are in near thermodynamic equilibrium with the salt medium. Utilizing information gained in corrosion testing of commercial alloys and in fundamental interpretations of the corrosion process, an alloy development program was conducted to provide a high temperature container material that combined corrosion resistance with useful mechanical properties. The program …

The Molten Salt Reactor Experiment design, component development, and engineering analysis is discussed. Materials studies for the Molten-Salt Reactor Program including metallurgy, in-pile tests, chemistry, engineering research, and fuel processing are described. (M.C.G.)

The report comprises seven sections. A separate abstract was prepared for each section. (J.R.D.)

Thermoluminescence in potassium dihydrogen phosphate (KDP) induced by Co/ sup 60/ gamma irradiation at liquid nitrogen temperature (-198 deg C) was investigated. Glow curves in the temperature range --196 to 0 deg C were measured for a series of gamma exposure dosages ranging from 10/sup 4/ roentgen to 5 x 10/sup 6/ roentgen. The heating rate used for glow curve measurements was 12 deg C per minute. Twice recrystallized Mallinckrodt reagent grade potassium dihydrogen phosphate, with a grain size between 100 and 170 mesh, was used for most samples. In the case of the powder samples, the glow curve for an exposure dose of 10/sup 4/ roentgen exhibited two peaks in this temperature range, one at approximately --78 deg C and the other at approximately -146 deg C. The -78 deg C peak split into two distinct peaks with increasing dosage. At still higher doses an additional peak at about -9 deg C became evident. This peak may, however, be due to aluminum oxide. Calculation of the trap depth, E, and the frequency factor, s, associated with the --78 deg C peak, by the approximate method of Grossweiner yielded values of 0.485 ev and 9.97 x 10/sup 10/ sec/sup -1/ …

Tests of Cambridge absolute filters, Model Sl-071, specified for use in the GCR-ORR Loop No. 2 as full-flow, primary coolant fiiters were completed. kD.O.P/ (dioctylphthalate) efficiency tests were performed on three filters in the as-received condition, on two filters following canning and thermal cycling, and on one of the canned fiIters following bsking out. None of the three units met the design criteria of 99.97% efficiency for removal of 0.3 micron particles in the as-received condition. The postthermal cycle efficiencies of the canned fiIters were slightly higher than their respective as-received efficiencies. At the corapletion of testing, the two fiiters canned for installation in the reactor facility had measured efficiencies of 99.855% and 99.93%. These values were judged acceptable for the intended application/su The thermal cycling of the two canned filters and the subsequent baking out of one of these units demonstrated that a limited amount of off-gas products would be given off/su Pressure drop tests were performed on the canned fiiters with instrument air (ambient temperature, atmospheric pressure) over a flow rate range of 150 to 530 lb/hr. Curves of pressure drop across each fiIter versus Reynolds number were plotted for air and He. (auth)

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 maximum stress calculated for the SMl-1 reactor vessel closure studs occurs during operation at full power. This value is 27,180 psi of which 19,800 psi is tension and 7380 psi bending. This stress does not include a stress concentration factor for effect of threads. It was eonservatively assumed the studs were initially tightened to a code allowable stress of 20,000 psi as specified in the ASME Code rather than the lesser stress obtained by the normal operating procedure. The maximum calculated stress occurs at the outside surface of the cover where the stress ranges from 318 psi in tension to 90,660 psi in compression. The alternating stress is 50,000 psi. According to the Navy Code for a stress range of 50,000 psi, the eover material ean safely undergo a maximum of 1600 cycles. It was estimated that the SM-1 will go through approximately 000 startup and shutdown cycles during a 20-yr life period, so the calculated stress is regarded as safe. For a transient eondition of 30 deg F/hr during heat-up, approximate temperature differences between the inside and outside surfaces of the cover were obtained. Temperature differentials between the inside and outside surfaces of the cover are increased by …

Dense partricles of ThO/sub 2/-UO/sub 2/ were prepared by a sol-gel process and vibratorily compacted into metal tubes to a density approaching 9.0 g/ cc. The steps in this method are all simple and can be carried out behind shielding, which is necessary for refabricating U/sup 233/ fuels. The sol-gel process consists of preparing a hydrous thoria sol, adding the U/sup 233/ as nitrate solution, evaporating to a gel, and finally calcining to almost theoretically dense oxide particles at orly 1150 deg C. The sol-gel-prepared oxide, after being sized, was compacted with a simple, inexpensive pneumatic vibrator. (auth)

Research was continued during the report period on the use of isotope neutron sources for producing short-lived radioisotopes. Experiments with a newly constructed betacounting cell are reported in which a 50-curie Be--Po neutron source was used. Study of the radiation chemistry of polymers was continued concerning the effects of polymer structure on free-radical formation. Free-radical formation in several additional polymers was studied. Preliminary work is also reported in an investigation of internal irradiation effects on the chemical activity of catalysts. (J.R.D.)

Science is impure in two ways. There is not a 'pure' science. By this I mean that physics impinges on astronomy, on the one hand, and chemistry on biology on the other. And not only does each support its neighbors but derives sustenance from them. The same can be said of chemistry. Biology is, perhaps, the example par excellence today of an 'impure' science. Beyond this, there is no 'pure' science itself divorced from human values. The importance of science to the humanities and the humanities to science in their complementary contribution to the variety of human life grows daily. The need for men familiar with both is imperative. We are faced today with a social decision resulting from our progress in molecular genetics at least equal to, and probably greater than, that required of us twenty years ago with the maturity of nuclear power.

This technical report introduces "some approximations into the basic quantum mechanical theory" so that the theory of the covalent bond and the molecular orbital method "can be combined into one which will yield quantitative rather than qualitative binding energies and cohesive energies and also distinct energy levels and band structure." This approach will provide a common method "suitable to both solid state physicists and physical chemists, for calculating the energy levels in metals and complex molecules." This report also contains figures detailing the findings. (Quotations taken from introduction)

This report examines radiation damage in solids, looking particularly at calculations and experiments that can provide quantitative predictions of damage.

Technical report which reports a study of the effects of extinction upon diffuse x-ray measurements.

Technical report describes how glasses and crystals subjected to ionizing radiation develop absorption bands and become colored. The coloring of defects can be used to determine how nuclear reactor induced defects anneal out or disappear as an irradiated sample is heated.

Technical report on a study where the birefringence of irradiated polyethylene was observed as a function of temperature. The data is consistent with a mechanism in which crosslinking limits the growth and annealing of crystallites. Crosslinks formed in material which was oriented at the time the crosslinks were formed, results in an oriented gel. This effect explains the birefringence and the persistence of nucleation sites at high temperatures.

Technical report about a study in the use of galvanic cells using solid electrolytes to obtain thermodynamic data at high temperatures to study the free energy of formation of chlorides using Daniell cells where all components are solid. "The experimental techniques used are presented, including cell construction, preparation of anhydrous materials, and the handling of reactive metals and hydroscopic materials for galvanic cells." from the abstract. Results are presented for magnesium chloride, cerium chloride, uranium chloride, and thorium chloride, and are compared with other available data.

Technical report covering an extensive investigation of the nature of fission fragment "damage" in various metals. During the investigation electron micrographs of fission fragment tracks in the BNL Graphite Reactor fuel element cores were made.

In this technical report studies on the sites in the porphyyrin moiety for the binding of vitamin B12 by serum proteins are presented. "The binding capacity of serum for radio-hydroxocobalamin is compared to that for radio-cyanocobalamin, and th effect of subsequent binding of radio-cyanocobalamin by prior addition of non-radioactive analogues and sodium cyanide are presented.

Technical report summarizing the evidence that "the capacity for spontaneous tumor formation is certain Nicotiana hybrids is genetically controlled and that genetic change during plant development, i.d. somatic mutation, is not causal to tumor formation." from the introduction.

Technical report about the investigation of whether low kinetic energy nuclear fission fragment particles create tracks in thin films similar to the tracks created from total kinetic energy fragments in excess of 150 Mev. The research goal is to understand the mechanism of track formation.

Technical report that attempts to address the controversy regarding the activation energy for the process of annealing single interstitials in irradiated graphite. The experiments determined that "the activation energy for the process of annealing single interstitials in neutron irradiated graphite and the absolute rate of formation of displaced atoms have been determined..." from the abstract.

Technical report describing "the interaction of IAA, kinetin and GA upon tumor induction in Nicotiana hybrids." from the abstract.

The green photosynthetic bacteria are characterized by the presence of either chlorobium chlorophyll (bacterioviridin)-65o or chlorobium chlorophyll-66o (numerical designation based on the position of the red-absorption peak in ether) z. Most strains of Chlorobium contain chlorophyll-66o which has its major red peak between 74 ° and 75 ° m/~ in FiFo. KATZ AND WASSINK z first reported an additional minor absorption peak at 81o mF for Chlorobium limicola in vivo and a corresponding minor peak at 780 m F in ethanol extracts. LARSEN (Figs. 6-11 in ref. 3) also observed this 8Io-mF absorption band in another Chlorobium strain and a corresponding peak at 77 ° m/~ in acetone extracts. In strain L of C. thiosulfatophilum the minor red peak appears at 800 mF, clearly resolved from the main peak of chlorophyll-65o at about 725 m/~ (see refs. I, 4). We have observed the minor red peak once again in Chloropseudomonas ethylicum, strain 2K (refs. 5, 6), as a shoulder at about 81o mF on the side of the 75o-mF peak of chlorophyll-66o (ref. 7). The evidence presented in this paper indicates that the absorption peak appearing between 800 and 81o m/, in vivo does not belong to chlorophyll-65 o (or …