High-quality welds with suitable properties for long-time elevated-temperature nuclear service are among the most critical needs in today's welding technology. Safe, reliable, and economic generation of future power depends on welded construction in systems such as Liquid Metal Fast Breeder Reactors (LMFBRs). Rapid thermal transients in LMFBR systems at coolant temperatures around 590 to 650/sup 0/C (1000 to 1200/sup 0/F) could cause creep and creep-fatigue damage that is not encountered in lower temperature reactor systems. The undesirable consequences of interaction between the two working fluids - sodium and steam - in the steam generators are also of major concern. Thus sound welds that have excellent reliability over a 30-year service life are essential. Several programs are actively underway at ORNL to satisfy this critical need and selected portions of three of these programs are discussed briefly.

A series of small scale experiments was conducted to evaluate TATB PBX blending. These included (1) washing a small quantity of LLL B9 PBX to remove dust, (2) reworking a portion of the LLL B9 lot, and (3) blending some LLL B7 PBX in the 30-litre reactor duplicating as nearly as possible the same conditions as were used for LLL B9 blending. Results from this limited study do not clearly define and isolate problem areas; however, the indications are sufficiently strong to warrant a change in our blending procedure. These changes have been made.

Although the multiple fission process is important at high neutron energies, most of the evaluations available today do not include these individual fission cross sections or their associated fission spectra. The representations used in the Los Alamos and Livermore libraries are described and calculations compared with 14-MeV integral experiments available on /sup 235/U, /sup 238/U, and /sup 239/Pu. Further work is needed to clearly delineate the specific problems in order to propose unique solutions.

Dose and exposure intercomparisons on a national or international basis have become an important component of quality assurance in the practice of good radiotherapy. A high degree of accuracy of ..gamma.. and x radiation dosimetry is essential in our international society, where medical information is so readily exchanged and used. The value of accurate dosimetry lies mainly in the avoidance of complications in normal tissue and an optimal degree of tumor control.

A consistent parametric calculation of a number of reactor types has been carried out to compare various methods of characterizing work energy from core-disruptive accidents. While the best method of characterizing damage is to do an explicit calculation of the actual energy partition, the finite expansion to the cover gas volume is a better measure of damage for parametric studies. Also, an inspection of the calculations done reveals the small fraction of total energy generated in an excursion which actually appears as system damage. Typical efficiencies for excursions calculated are 0.5 to 2.0 percent.

A two-day workshop was held on August 5 and 6, 1976, to discuss phase space damping (''cooling'') of particle beams. Two cooling techniques have been developed: in stochastic cooling the spread of amplitudes in a beam is reduced by a feedback signal derived from the statistical fluctuations in the beam; in electron cooling an electron beam having the same mean velocity as the heavy particle (proton or antiproton) beam coincides with the heavy beam in part of the orbit. Viewed in the center-of-mass system, the electrons are ''cold'' and the protons ''hot'', and in the approach to thermal equilibrium the protons are cooled down; in the lab system this means their fluctuations from the mean are reduced. Both these cooling techniques are discussed, especially with a view to their application to the production of intense high-quality antiproton beams suitable for colliding beam physics.

Documentation of the discussion held as a group and subsequently, in three subsections of solar and conventional power generation, industrial/agricultural process heat, and building heating and cooling is presented. In each section, the discussions are summarized to bring together the common aspects of the problems. (MHR)

Thirty marine scientists involved in Energy Research and Development Administration (ERDA)-supported marine research on the west coast of the United States met March 17-19, 1976, at the Asilomar Conference Center, Monterey, California. The objective of this workshop was to define the elements of an integrated research program that would contribute to a better knowledge of the potential impact of pollutants on coastal ecosystems from energy-related fuel cycles. One of the long-range objectives of the Division of Biomedical and Environmental Research in ERDA is to support research on processes and mechanisms that occur in the coastal waters that would allow assessment of the impact of energy technology fuel cycles, i.e., nuclear, oil and gas, coal, and solar. Additionally, the research has an objective of providing a basic environmental data base which will aid in the technological development and deployment of energy supply systems. While the research is not designed for the purposes of standard setting or for regulatory processes; nevertheless, it may, in the long term, contribute to a better basis for setting standards that are in the balanced best interest of both energy production and the preservation of our valuable coastal ecosystems. It was recognized that other Federal agencies also …

Separate abstracts were prepared for the 71 papers presented. (JFP)

Problems of sample preparation can be avoided by analyzing the solids as slurries. A sealed sample cell with a belt-driven stirrer was constructed for use with the GE XRD-3 spectrometer. A problem arose owing to radiolytic gas; an open, bottom-window cell would solve the problem. A ThO/sub 2/ analysis was carried out; the ThO/sub 2/ assay was observed to increase with prolonged x-ray exposure. (DLC)

Accurate taping patterns are essential in paper and plastic lapped underground cables. A newly developed radiographic system makes it possible to examine the structure of cables and splices in a nondestructive manner. This technique appears to be an effective tool for use in both the monitoring of the accuracy of lapping techniques and as an aid in locating defective portions of existing cables. A discussion of the method and some preliminary results are reported.

Flash x-ray radiography is presently being evaluated as a possible diagnostic technique for monitoring fuel motion in LMFBR Safety Test Facilities. X-ray radiographs have been obtained on film of various reactor core configurations with 30-MeV bremsstrahlung filtered through as much as 100-mm thickness of steel which was used to simulate the reactor containment vessels. These pictures demonstrate that the transmitted x-rays retain sufficient information to satisfy the spatial resolution and areal density requirements not only for small arrays but also for a full subassembly. Electro-optical imaging systems, rather than film, and modern linac x-ray sources are being considered in order to satisfy the additional repetition rate requirement of nearly 10/sup 3/ pictures per second during extreme reactor power transients. The imaging systems presently under consideration are described and the experimentally determined detector sensitivity and x-ray source intensity required for the one system studied most extensively are presented.

The 5f electron spectra in NpO/sub 2/ and PuO/sub 2/ were studied by XPS. Using intensity measurements and multiplet structure, the configuration 5f/sup 3/ was assigned to NpO/sub 2/. Although NpO/sub 2/ exhibits anamolous magnetic behavior similar to TmSe (a valence fluctuation system), XPS results do not support the valence fluctuation model for NpO/sub 2/.

The hereditary disease Xeroderma Pigmentosum (XP) is characterized by a high sensitivity to sunlight and the appearance at an early age of nonmelanoma skin cancer. The prevalence of both nonmelanoma and malignant melanoma among a population of XP individuals is several orders of magnitude greater than in the general population. The connection between photobiology and cancer arises because cells of XP individuals are defective in one or more of the mechanisms for repairing UV damage to DNA. The repair mechanisms are outlined schematically and discussed.

The purpose of this work is to develop a zero-dimensional group collapsing capability that will enhance the applicability of ERDA's format and super-group standardization efforts. New physics algorithms are introduced which allow an exact collapsing to a subset group structure.