[en] A supplemental stress analysis of the LOFT Downcomer Instrumentation Assembly (DIA) has been completed in accordance with the stress requirements of Section III of the ASME Code. Both thermal loads, due to LOCE and operating conditions, and fluid loads were considered. The following conclusions were made: (1) Inconel 600 is an acceptable material for the pressure tubes. (2) The flowmeter can be attached to the DIA with ¹/₄-inch diameter, SA-193 type B8M screws. They should be lubricated with two coats of Neolube and torqued to 1.25 ft-lbs. This applies to all of the screws attaching the flowmeter to the DIA. As an alterative, SA-453, grade 600 screws may be used. They should be coated with 2 coats of Neolube and torqued to 4.9 ft-lbs (4.5 ft-lbs is acceptable). (3) The method of mounting the instrument leads and the pressure tubes is adequate