Design Of A New Type Of Rector Sump Strainer Based On Distorted Model

Sump Strainer is key equipment of Nuclear Power Plant safety system, filter the debris of containment spray system and safety injection system and make sure normal operation of systems. In 1992, Barseb?ck Kraft AB Nuclear Power Plant came up a sump strainer blockage accident, caused a pump cavitation, and Reactor Spay System cannot be used. The accident made the function of Sump Strainer a new research hotspot for nuclear safety study. All of the advanced nuclear countries start to develop strategy research and design improvements.New type of sump strainer is consisted of filter frame and filter module. The filter modules are installed on the filter frame and several filter frame connection in series to a sump strainer. The new type of sump strainer should meet the requirement of flow rate and filter fineness and also to make sure the head loss of sump strainer is low enough to not make the pump cavitation which is head loss requirement.Sump strainer dimension and flow rate are very large, so the prototype test cannot be performed for operational and economical reasons. By using of similarity theory, the test model’s dimension is reduced and test parameters are reduced to confirm the model is geometry, motion and dynamics similarity with prototype. Based on distorted theory which the similarity is different for the three-dimensional physical dimension, a sump strainer distorted model is developed for sump strainer head loss test, it only reduced the length of prototype and keep the width, height and filter hole. Consider of sump strainer is consist of several same filter frames. A filter frame is chosen to be the distorted model. Using equation analysis method, the reduced value of flow rate, debris quantity can be calculated. The distorted model is approved to similar with prototype by similarity calculation.and is good at reductive property, economics and operability.According to test parameter and distorted model’s requirement, model test is carried out. Then according to sump strainer different work condition(full load condition and thin bed condition) and the different type of filter module(triple, double and single), a series of head loss tests are performed to verify the head loss of sump strainer, totally 7 different tests for different work condition and different filter module.Head loss test results verify that triple filter module will generate low head loss at thin bed condition and high head loss at full load condition, double filter module will generate high head loss at thin bed condition and low head loss at full load condition compare to triple filter module, single filter module will generate high head loss as small filter area. According to similarity factor of distorted model and prototype, the prototype’s head loss at work condition(120℃) can be calculated.