[en] Guidelines for evaluating potential surface facilities to be used for the storage of high-level radioactive wastes on the Nevada Test Site in southern Nevada include the consideration of the potential for flooding. Those floods that are considered to constitute the principal flood hazards for these facilities are the 100- and 500-year floods, and the maximum potential flood. Flood-prone areas for the three floods with present natural-channel conditions were defined for the eastern part of Jackass Flats in the southwestern part of the Nevada Test Site. The 100-year flood-prone areas would closely parallel most stream channels with very few occurrences of out-of-bank flooding between adjacent channels. Out-of-bank flooding would occur at depths of less than 2 feet with mean velocities as much as 7 feet per second. Channel flood depths would range from 1 to 9 feet and mean velocities would range from 3 to 9 feet per second. The 500-year flood would exceed the discharge capacities of all channels except for Topopah Wash and some channels in the upstream reaches of a few tributaries. Out-of-bank flows between adjacent channels would occur at depths as much as 3 feet with mean velocities of more than 7 feet per second. Channel flood depths would range from 1 to 12 feet and mean velocities would range from 3 to 13 feet per second. The maximum potential flood would inundate most of the study area. Excluded areas would be those located immediately east of the upstream reach of Topopah Wash and between upstream channel reaches of some tributaries. Out-of-bank flows between adjacent channels would occur at depths as much as 5 feet with mean velocities as much s 13 feet per second. Channel flood depth would range from 2 to 23 feet and mean velocities would range from 4 to 26 feet per second

[en] We have seen what little is known about how strand breakage and nucleotide damage contribute to overall lethality in phage or phage DNA irradiated under direct action conditions and indirect action conditions and assayed in repair-proficient bacteria. Repair-deficient organisms would naturally display abnormal sensitivity to those lesions affected by the defective repair system. Most bacteria, including those used in the studies cited here, have no known double-strand break repair. Organisms such as Micrococcus radiodurans and (at least some) mammalian cells which possess repair capability for double-strand breaks, can be expected to show less double-strand break sensitivity, providing the breaks are repaired with fidelity. (It is also interesting to speculate about the possibility for new discoveries of repair systems acting on the as yet uncharacterized, but obviously very important, other nucleotide damage). The nature and LET dependence of lethal non-break nucleotide events has scarcely been investigated, and the problem badly needs clever new ideas and better physical and chemical probes

No abstract available

[en] Increased cost of lead is promoting enhanced usage of common building materials for shielding in diagnostic medical and dental facilities where only a few half-value layers (HVLs) are needed. Attenuation of primary beam X-ray photons in gypsum wallboard as a function of kVp, filtration, and wallboard thickness have been measured. Findings, obtained using a Victoreen 555 with an 0.1 DAS probe in poor geometry, are substantially in agreement with the sparse data in the literature but extend to thicker wall configurations and different kVp and filtration parameters. These findings are of value in maximizing the benefit/cost ratio for diagnostic shielding, and strengthen the conviction that, where used for shielding purposes, common building materials must be installed carefully and HVL-depth dependence considered thoroughly. (author)

[en] A common use for Gammacell 220 (Atomic Energy of Canada, Ltd.) drawer-type ⁶⁰Co irradiators is to deliver doses of hundreds or thousands of rads to a variety of biological specimens ranging from mammalian cell suspensions to whole animals such as mice or hamsters. With high ⁶⁰Co loading such exposures may require only a few seconds even with attenuators present. Since absorbed dose typically is calculated on the basis of time spent in the center of the radiation field, and automatic timers typically begin timing only when the specimen reaches the center of the radiation field, radiation absorbed during transit can significantly modify the dose expected from standard calculations when the irradiation time is short. We measured the magnitude and position dependence of Gamma-cell 220 drawer transit doses with film dosimetry, and obtained data permitting calculation of actual samples dose for different ⁶⁰Co loadings and for off-center sample positioning. (author)

[en] Separate abstracts were prepared for the 21 papers in the proceedings of the Health Physics Society 1981 Summer School on Reactor Health Physics

No abstract available

No abstract available

[en] Guidelines are suggested for baccalaureate health physics program content based on the schema used in a prior publication. The Guidelines assume a program with a primary emphasis on generalized health physics and presuppose an institutional breadth coursework requirement. Methods of strengthening areas of current general weakness are proposed, and one version of a coursework model is presented. Comments to the author and the Manpower and Professional Education Committee of the Health Physics Society are welcomed

[en] Herpes simplex viruses and cytomegaloviruses were ⁶⁰Co γ-irradiated at -76⁰C and a dose-rate of 6.5 to 7.0 krad/min. The low irradiation temperature was chosen to minimize damage to surface antigens by radiation-induced radicals. Comparisons were made of the survival of propagative ability and the antigenicity of irradiated virus. The survival curves were consistent with single-hit exponential inactivation kinetics, and a virus-specific immune response was induced after a single immunization with completely inactivated virus. The titre of antibody reached was comparable to that expected after a single inoculation of viable virus and the inactivated virus could function as a stimulating antigen in a lymphocyte transformation assay. The results indicate that the antigenic components on individual virions remain largely intact after irradiation. (U.K.)