METHOD FOR EXTRACTING UNDERWATER FOREIGN MATTERS FOR NUCLEAR POWER STATION

摘要

A method for extracting underwater foreign matters for a nuclear power station, comprising the following steps: step 1) a pumping pipeline (1) pumps foreign matters and cooling water in a reactor vessel through a pumping opening (2) formed in the bottom end of the pumping pipeline (1) under the pumping effect of a water pump (5) disposed in a pumping pipeline (1); step 2) the foreign matters and the cooling water pass through an electric valve (3) disposed at the joint of the upper part of the pumping opening (2) and the pumping pipeline (1); step 3) the foreign matters and the cooling water passing through the electric valve (3) are filtered by a filter screen (4) disposed under the water pump (5), the cooling water pass through the filter screen (4), and the foreign matters touch the filter screen (4) and trigger a touch switch (6) disposed on the filter screen (4) so that the touch switch (6) is turned on; and step 4) after the touch switch (6) is triggered to be turned on, the electric valve (3) is controlled to be closed, and the foreign matters are stopped in the pumping pipeline (1) between the filter screen (4) and the valve (10) of the electric valve (3). The whole extraction method is convenient to operate, and can be operated in a blind manner even the specific position of foreign matters in the reactor vessel is not known.