In concurrent flow of two phase mixtures there exists a velocity difference between the vapor and liquid phases. This difference in velocity is known as the slip velocity. The prediction of slip is the subject of Part I. In boiling systems there is some heat transfer rate at which nucleste boiling becomes unstable. At this point the separate bubbles coalesce forming an insulating vapor film on the heat transfer surface resulting in the destruction, or burnout, of the heater. The prediction of the conditions causing burnout is the subject of Part II.

The General Electric Company is designing and building a 180,000 kilowatt nuclear power plant for the Commonwealth Edison Company at a site 47 miles southwest of Chicago. The construction permit was issued on May 4, 1956 but is subject to submittal to the Commission of a final hazards summary report and a finding by the Commission that the final design provides reasonable assurances that the health and safety of the public will not be endangered by operation of the reactor in accordance with the specified procedures.