This report covers work done by the Pile Engineering Groups and work done on special assignments. Topics covered include: slug blistering and corrosion; graphite allocation to DR pile; slug molding; segmental discharge; Van Stone corrosion; flow laboratory modifications; downcomer at B pile; downcomer at D pile; annealing of pile graphite; replacement of pile atmosphere with CO{sub 2}; unit motion; beta experiment; can opening; slug annealing; new technical building, 300 area; and ruptured slugs.

Following the shutdown of the B Pile in March 1946 a method was devised for monitoring the sub-critical reactivity such that any significant change in neutron flux would be detected. This report summarizes the status of the unit until its start up in July 1948.

Using an apparatus described in a preceeding paper the reaction rate of the fluorination of UO/sub 2/ by HF was measured under the condition of a gradually increasing temperature. UF/sub 4/ made in this way did not show caking although final reaction temperatures ranged as high as 700 deg C. The rate of reaction was found to be greater than the rate measured under isothermal conditions at the highest temperature attained during the continuous increase as long as this final temperature was above 550 deg C. (auth)