Effect of barriers on sodium mist deposition on LMFBR components.

Abstract

Tests were made to evaluate the effect of two barriers (a convection barrier and a drip receiver) against sodium mist deposition on LMFBR conponents in the cover gas space. Two models of LMFBR rotating shield plugs (1,800 mm in height, 680 and 850 mm in diameter) and a sodium test tank were manufactured for this purpose, and the mist deposition rate on the walls of these models was measured both in the cases with and without a barrier. The sodium pool temperature during the test was 580°C. In parallel with these tests, the relation between the form of deposit and the wall temperature was examined to determine the critical wall temperature above which deposits do not accumulate. This was conducted by exposing a vertical stainless steel cylinder to cover gas entrained with mist over 500°C sodium for 30 to 1,000 h. The test results revealed that the barriers functioned effectively, and they reduced the local deposition rate near top of the annulus by three orders of magnitude relative to the cases without a ...