[en] Ten littermate miniature swine were used to determine the effect of a 2 week course of hyperbaric oxygenation applied immediately after an administered dose of 1800 rad of X-rays on the total collagen content, collagen synthesis rate and subcutaneous oxygen tension in irradiated and nonirradiated skin. Half of them received hyperbaric oxygenation and half were maintained on normal air at ambient pressure. The oxygen treated group had significantly lower total mature collagen content (p < .01) and collagen synthesis rate (p < .05) in the irradiated skin than in the nonirradiated skin at 240 days after X-ray exposures. The group on normal air showed no differences in collagen content, collagen synthesis rate and subcutaneous oxygen tension between irradiated and nonirradiated skin. Early changes in collagen content and rate of synthesis occurred in both treatment groups and were time-related. It is suggested that this reflects regular periodic changes in fibroblastic activity, possibly related to hair growth cycles

No abstract available

No abstract available

[en] Complete tabulated data of the mean velocity profiles, wall shear stress distribution and all components of the Reynolds stresses are presented for developed single-phase flow through a square-pitch rod array (p/d = 1.107) at Reynolds numbers of 22.6 x 10³, 46.3 x 10³ and 207.6 x 10³

No abstract available

[en] This study investigates motor-operated globe valve (MOV) performance in a liquid sodium environment as reported to the Centralized Reliability Data Organization (CREDO) from site representatives at several liquid metal reactors and liquid metal test facilities. The CREDO data base contains engineering histories for 179 motor-operated glove valves. Thirty nine failures have been documented for these components in over 8.7 million hours of operation. The most common MOV events were anomalies with the limit and torque switches, although human initiated problems were also frequent causes of failures. The failure data suggest that an improved preventive maintenance program with a higher frequency of inspection of the limit and torque switches should increase MOV availability and reliability. The event rate for all failure modes was computed as 4.47 events per 10⁸ operating hours by assuming a Poisson distribution of failure over valve operating time. The 5% and 95% confidence limits based on a chi-squared (χ²) probability distribution function were computed as 3.36 and 5.83 events per 10⁶ operating hours, respectively. The operating performance of these liquid metal MOVs was compared to similar data for MOVs in commercial light water reactors and was found to exhibit similar failure rates

[en] The adhesion of electrodeposited nickel to U-Nb alloys is of interest for joining materials by plating and for protection from corrosive environments. Because uranium alloys are passive, a surface preparation procedure such as etching in acid is necessary before plating to provide mechanical keying of the electrodeposit. When nitric acid has served as the etchant, there have been occasional violent reactions between the oxidizing acid and the alloy. We have observed that a sulfuric acid/hydrochloric acid etchant eliminates this problem. Furthermore, quantitative test data for nominal U-6 wt % Nb alloys plated with nickel demonstrated that with parts etched anodically in a solution of sulfuric and hydrochloric acids, high-strength bonds can be obtained; nominal shear and tensile bond strengths were 250 and 115 MN/m² respectively. Electrochemically etched U-Nb rods joined to 7075-T6 Al rods with thick nickel plating showed a nominal fracture stress in excess of 470 MN/m². Bare and Ni-plated tensile bars showed no significant changes in mechanical properties due to electrochemical etching and plating, but did exhibit changes due to Nb content and heat treatment

[en] A technique for avoiding cold-shut defects in deep, single-pass, electron beam welds is described and evaluated. Shims of an appropriate alloying metal are interleaved in the joint before welding, and during the welding process the shim is melted and mixed into the weld metal, lowering the solidification temperature and thus preventing the formation of cold-shuts. For uranium and some of its low-dilution alloys, the shim may be made of copper

[en] Shims of an appropriate alloying metal are interleaved in the joint before welding, and during the welding process, the shim is melted and mixed into the weld metal, lowering the solidification temperature and thus preventing the formation of cold-shuts. For uranium and some of its low-dilution alloys, the shim may be made of copper. 13 refs

[en] The authors report the results of their studies of the thermal expansion characteristics of hot- and warm-rolled α-U plate and hot-extruded pipe. The hot-rolled plate had a high coefficient of thermal expansion (CTE) in the rolling direction and a low CTE in the transverse direction. This trend was reversed in both as-warm-rolled plate and plate that was both warm rolled and annealed. In pipe that was hot extruded at large reduction ratios, it was possible to correlate the CTE for the extrusion, radial and circumferential directions with the CTE for rolling, transverse and normal directions in the hot-rolled plate. (Auth.)