The choice of materials and other vessel design decisions necessary to provide the desired life expectancy for the FTR vessel are partially dependent upon estimates of the number and type of reactor shutdowns and startups which may be anticipated. Current estimates of these so-called "cycles" are given, including scram frequency, experimental outage frequency, standard shutdowns and startups, and rapid controlled shutdowns. Also discussed are abnormal heatup or cooldown, and tentative goals for temperature controls. MTR, ETR, and typical PRTR operating histories are tabulated.

The FTR vessel wall will be cooled with inlet primary coolant which bypasses the core and flows through an annulus formed by the vessel wall and the thermal barrier. heat transfer to the by-pass coolant stream is by raial conduction from the surrounding sodium pool through the thermal barrier wall. In the analysis, the temperature rise of the by-pass coolant stream was derived as a function of the wall thickness of the thermal barrier and the flow rate of the by-pass stream.

The major technical bases for the FFTF first core fuel assembly conceptual design are presented in four general categories: (1) thermal, (2) hydraulic, (3) structural and (4) performance-manufacturing design characteristics. Recommended design values and conceptual engineering drawings of the fuel pin and subassembly are included .

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Crawford Martin, regarding a legal question submitted for clarification;The legality of a state department head's decision to withhold insurance premium payments from the for salaries of employees for only one insurance company.

The following activities were conducted during the month of April 1969: continued effort toward completion of the detailed design of the PMC-2 converter, conducted technical liaison with Westinghouse with respect to the power cable specification, conducted potting test for evaluation of material suitable for SNAP-23A converter PMC-2 leak specification, and completed design of parts for the Weld Development Program. Test data evaluation and analysis were performed on the following long-term test devices during February 1969: experimental mockup converter No. 2 (EMC-2), experimental mockup converter No. 3 (EMC-3), prototype mockup converter No. 1B (PMC-1B), 10-couple modules 1 and 3, 10-couple modules 5 through 12 on design-of-experiments tests, 6-couple module 23A3, and converter 23 P-2.