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The Idaho National Laboratory (INL) has been at the forefront of developing methods to reduce the cost and schedule of deactivating spent fuel pools (SFP). Several pools have been deactivated at the INL using an underwater approach with divers. These projects provided a basis for the INL cooperation with the Dresden Nuclear Power Station Unit 1 SFP (Exelon Generation Company) deactivation. It represents the first time that a commercial nuclear power plant (NPP) SFP was decommissioned using this underwater coating process. This approach has advantages in many aspects, particularly in reducing airborne contamination and allowing safer, more cost effective deactivation. The INL pioneered underwater coating process was used to decommission three SFPs with a total combined pool volume of over 900,000 gallons. INL provided engineering support and shared project plans to successfully initiate the Dresden project. This report outlines the steps taken by INL and Exelon to decommission SFPs using the underwater coating process. The rationale used to select the underwater coating process and the advantages and disadvantages are described. Special circumstances are also discussed, such as the use of a remotely-operated underwater vehicle to visually and radiologically map the pool areas that were not readily accessible. A larger project, the INTEC-603 SFP in-situ (grouting) deactivation, is reviewed. Several specific areas where special equipment was employed are discussed and a Lessons Learned evaluation is included.

IN the initial stages of the biomineralization of abalone shells, a primer layer of oriented calcite crystals grows on a nucleating protein sheet1,2. The deposition of this primer is followed by an abrupt transition to c-axis-oriented crystals of aragonite, another crystalline form of calcium carbonate. The formation of each of the two crystal types is accompanied by the synthesis of specific polyanionic proteins1–3, suggesting that cooperative interactions between these proteins and the inorganic ions during crystal nucleation and growth control the phase of the deposited mineral and that differential expression of the proteins allows the organism to induce phase changes. It is known that soluble shell proteins can control crystal morphology4–10, but it has been suspected that the switch in phase—from calcite to aragonite—might require the deposition of a new nucleating protein sheet. Here we describe in vitro studies of the crystallization of calcium carbonate in the presence of soluble polyanionic proteins extracted from abalone shell. We find that these proteins alone are sufficient to control the crystal phase, allowing us to switch abruptly and sequentially between aragonite and calcite without the need for deposition of an intervening protein sheet. These results show that soluble organic components can exert greater control over hierarchical biomineral growth than hitherto suspected, offering the prospect of similar phase control in materials chemistry.

A test vehicle to obtain multiaxial failure envelopes for filamentary composites was designed. The test sample consisted of a filament-wound pressure vessel with the dome and tangent line regions of the chamber reinforced with low-modulus cast-epoxy pieces. Finite-element stress analysis was used to design the shape of the epoxy so that the maximum stress and strains and, thus, the failure, would occur in the cylindrical section of the chamber. The device was proven in initial tests.

The effect of dynamic loading on the stress-strain and failure characteristics of nugget sandstone was investigated at strain rates from 102 to 103 per second and confining pressures to 30 ksi. The apparatus developed for these experiments consists of a conventional split Hopkinson bar enclosed in a pressure vessel. The apparatus permitted determination and recording of all principal stresses and strains from the onset of loading to failure. A description of the experimental techniques used in obtaining data including the method of determining stress and strain, the method of reducing data, and use of various shaped projectiles to tailor the input-stress wave are reported together with experimental results for nugget sandstone. All rocks tested exhibited an increase in strength as the loading rate increased. The dynamic stress-strain curves were similar in shape to curves from quasi-static testing of the same material.

In bacterial conjugation in the Escherichia coli system, two cells with heterosexual properties, donor and receptor cells, form a temporary pair and DNA is transferred up to the amount of a whole bacterial chromosome which would represent, if stretched out, a 1 mm long molecule. The physical mode of DNA transfer between two cells which have tight cell walls and cytoplasmic membranes is far from clear.

A study of the diurnal migration and geographic extent of the deep layers of sound scatterers found in the ocean has been made with fathograms and oscillographic records of reverberation received with vertically directed projectors. The deep scattering layer was observed consistently throughout the area investigated. The principal features of the diurnal observations are the movement of the deep scattering layer toward the surface in the evening and away from the surface in the morning. Observations of the diurnal migration of plankton made during the acoustic observations indicates that the cause of the sound scattering is associated with organisms. Some observations indicate that the scatterers near the surface are found in “swarms” rather than in well‐defined strata. With conditions of strong downward refraction, the layer acts somewhat like a false bottom, giving rise to a pronounced increase of horizontal reverberation strength which is not observed in the absence of strong downward refraction. Forward scattering from the deep layer is observed in transmission measurements as a ragged “pip” following the signal.