Progress report for the Piqua Reactor Operations Analysis Program describing observations and analyses at the Piqua Nuclear Power Facility (PNPF). The program goals are to monitor operations and collect data in order to ensure that the plant's operation is safe, to improve design and performance, to evaluate the performance and lifetime of the plant's components and systems, to evaluate plant safety and safeguards, and to disseminate all information to the scientific community.

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Tests were conducted to evaluate the performance of a 10-in. flow controller in sodium at temperatures up to 1200 deg F. Torque tube reliability was determined by extensive mechanical cycling tests and further checking with a helium mass-spectrometer leak detector. Flow control performance and valve vibration characteristics were tested and evaluated and flow rate limits were established. The valve assembly was subjected to a thermal shock test program simulated to represent the most severe conditions likely to be encountered during a minimum l0-yr lifetime. (auth)

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As a part of the effort to establish the vapor pressure of /sup 3/He as the international temperature scale between 0.3 and 3.2 deg K, the manometric contections from /sup 4/He to /sup 3/He are being determined. The results of a single run did not agree with the predicted values. Calculations indicated that a two to one thermal diffusion column cascade is more efficient than a three to one cascade for separation of neon isotopes. Gaseous impurities in neon were reduced from 3.40 to 0.26% by passing the impure gas through a charcoal trap at liquid nitrogen temperature. About 15 liters of gas containing 9% /sup 78/Kr and /sup 80/Kr were accumulated. Calculations to determine the shape factors for the thermal diffusion system were completed. A six-stage cascade system was converted to an eight-stage cascade system of ten hot-wire and concentric-tube columns. Prior to the conversion the sixstage system enriched natural methane to 74%. Additionally, 74% of that enriched methane product was mass 17. The concentric-tube columns completed the purification of a commercially enriched methane from 60% to over 90% /sup 13/C in the total carbon, About eight grams of the methane product were accumulated. A method was developed for …

A diffusion couple technique was developed and standardized for the purpose of obtaining meaningful data regarding the diffusion kinetics of the Al-- Ni--U system. The technique entailed hot pressing under a dynamic vacuum and subsequent isothermal soaking treatments within evacuated quartz tubes for periods of 10 to 7000 hr at temperatures of 850, 750, 850, andd 950 deg F. In addition, the nickel barrier bond between Type 1100 aluminum cladding and cast U- 3.5% Mo fuel alloy was metallographically examined on four fuel cylinders fabricated according to Piqua procedure. One cylinder was inspected in the as fabricated'' conditions, and the three others after 1000, 2000, and 4000 hr of isothemnal soaking in Santowax OMP at 750 deg F in an autoclave under 100 psig of nitrogen. The following conclusions were obtained: 1) The penetration of aluminum into nickel followed a parabolic relationship with time. The penetration coefficient was graphically determined as a function of temperature. 2) The nickel penetration data generated by the diffusion couple technique were slightly higher thand those derived from the cylinder bond study. The maximum discrepancy was 20%. This disagreement was attributed to the geometry of the tubular specimens and to the interface displacements which occurred …