The process criteria proposed use of the existing organic wash column, 10, as a stripping column for the neptunium accumulation and isolation cycles. It is now proposed to employ a new processing concept which will permit the use of the scrub section of the neptunium extraction column, 1S, for neptunium stripping thereby obviating the use of the 10 Column. This proposed new scheme will provide increased neptunium stripping efficiency and greater processing flexibility for the 1S Column. The revision will require four new jumpers, but will permit the deletion of eight jumpers required for the original proposal. This document discusses the technical bases and incentives for the proposed change and presents revised flow diagrams and jumper routings.

None

None

The longitudinal (axial) flux distribution in the Hanford production reactors quite closely approximates a ``chopped`` cosine. Consequently, any longitudinally uniform charge placed in a reactor will produce a daughter product with a specific activity distribution which also approximates a cosine. Such a distribution has an average-to-maximum specific activity of about 0.7 and is not desirable when product uniformity is required.

Neutron activation analysis provides the extremely high sensitivity necessary for the measurement of many trace elements. Activation techniques are presently being used to measure the concentrations of various undesirable parent isotopes in reactor process tubing, slug jackets and their corrosion film, and in process vater and vater treatment chemicals. The interpretation of results from activation analysis are sometimes complicated by the fact that a given radioisotope may be produced by fission neutrons (threshold reactions) from other elements as well as by the more common thermal neutron (n,{gamma}) reactions. Shielding the sample with cadmium prior to irradiation or irradiating in the graphite reflector will minimize the contributions from thermal or fission neutrons, respectively. The purpose of this study has been to measure the ratios and magnitudes of the thermal and fission fluxes in process tubing and to compare these with values at locations where neutron activations can be performed. Also, it was of interest to measure the ratios and magnitudes of the thermal and fission fluxes from a point in the lattice to a point well into the graphite reflector, and to determine if the fission neutron spectrum as measured by two threshold reactions, changes appreciably over this region. These data …

Canning bath Al-Si, supplied from offsite vendors and reclaimed lathe turnings in the 313 building, is used in the production of I & E fuel elements. A study was made of the effect of increasing the Ni content to over 0.5% in the canning baths, in order that all of the X-8001 scrap could be reclaimed. Effect on bond quality, weld integrity, and canning bath operation was studied. Based on adverse weld quality, slight loss in reactivity, and potential for furnace channel plugging, it is recommended that the present Ni specification of 0.5% maximum remain unchanged.

Process tube and fuel jacket failures due to corrosion are recurring problems in the operation of nuclear reactors and are generally accentuated by coolant temperature increases. Water mixer fuel pieces which mix the subchannel flow streams are used in the production reactor fuel columns to reduce peripheral and hole-to-annulus coolant temperature disparities and, thus, to reduce corrosion problems. The mixer in current use is approximately two inches long and is attached to a six inch fuel piece. This fuel element with attached mixer is generally placed as the seventh fuel element from the downstream end of the charge. A new miser design has been proposed and is shown. Its basic operation is similar to that of the present design (H-3-17493) in that it exchanges the flow stream in the central hole with fluid in the annulus. The standard mixer utilizes circular interchannels to perform the fluid interchange, whereas, the new mixer uses larger channels of rectangular cross-section. The purpose of this study was to evaluate the mixing effectiveness and pressure loss characteristic of this new mixer and to compare it with the performance of the standard mixer.

Experiments have been conducted in the Hydraulics Laboratory, at the request of IPD`s Mechanical Development-A Operation, to determine the energy losses of various enlarged outlet fitting combinations. These experiments were conducted an steady state runs and allow the determination of the normal operating point (flow rate) of a reactor process channel under selected conditions of front header pressure and fuel charge. No attempt is made to make a mechanical or economic evaluation of the particular fitting combinations, although observations were noted which might bear on this evaluation. It is very important for the reader to bear in mind that changing outlet fittings will definitely affect the reactor tube power limits and outlet vater temperature limits. The size of the outlet fittings largely determines the present outlet temperature limits of the old reactors. The flow characteristics of these present fittings cause some degree of pressurization to suppress boiling on the fuel charge and also cause dual Panellit trip protection for certain flow changes and for power surges. Enlargement of the outlet fittings may actually reduce the allowable outlet coolant temperature limits. Since these effects cannot be determined on the apparatus used in these experiments, a complete discussion of this point is …