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In heat exchangers, in which the walls are heated by intemal heat sources, it is possible for wall temperatures greater than the mean to occur in the corners of noncircular flow Passages. Thus in a square or triangular passage low velocities occur in the corners, and the resulting decrease in the heat transfer coefficient produces higher temperatures in the walls at these locations. A generalized analysis is presented taking into account the variation in the heat transfer coefficient along the surface, by which it is possible to compute local temperatures in the walls of noncircular flow passages in the vicinity of the corners. Computations have been made for a representative component composed of a honey comb of rectangular passages. The resulting temperature at the hottest point is approximately 125 deg F greater than the unifomn plate temperature. This analysis is based on a 90 deg angle between the plate and retaining plate, and a uniforn source distribution throughout all plates. Had the angle between the primary plate and retaining plate been much less than 90 deg on both sides, then the resulting local temperature rise would be several times the above value. If the primary plate and retaining plate are …

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Higher operating levels in the 100 Area piles have caused alarming increases in pile effluent activity and pressure drop through the process tubes. Projected additional increases in power level may not be possible unless the problems of film formation and pile effluent activity are overcome. Although a solution to these problems is not the responsibility of the Power Division, we do not have an interest in seeing that any proposed solution meets the test of operational practicability. Consequently, this was written in order that pertinent water treatment information may be readily available.

The Pu in one batch (160 gms) is precipitated in a purification hood and waste supernatant is then transferred to the storage tank in one of the recovery hoods. Under normal process conditions a small amount of Pu remains in the supernatant. However, it is possible, though extremely unlikely, that the entire 160 grams would be transferred to the waste storage tank. The supernatants are transferred to an evaporator where they are concentrated. This evaporator has dimensions approximately the same as those of the storage tank, however, as concentration proceeds, the remaining solution can pass to a geometry more favorable for a chain reaction. There should be definite assurance before evaporation is begun that the amount of Pu in the evaporator does not exceed 160 grams. It is concluded that there is no objection, from a nuclear safety standpoint, to the discontinuance of analysis of the supernatants.