Back to 2007 listNuclear Reactor Shut Down for the Purpose of Inspecting Extraction Steam Check Valve No.1 (A) on Hamaoka Nuclear Power Station Reactor No.5
February 16, 2007
Chubu Electric Power Co., Inc.
Water drops were confirmed to be leaking from the bonnet flange on extraction steam check valve No.1 (A) (*2) during regulated operations (*1) (adjustment operations) at the rated heat output of reactor No.5 at the Hamaoka Nuclear Power Station (rated electrical output of 1.38 million kW) on February 12, and the leak was halted through extra tightening.
It was discovered afterwards that the gasket (*3) attached to the flange did not match specifications. The relevant gasket is scheduled to be replaced, once a replacement unit has been arranged and all other preparations have been put in place.
The above circumstances have not resulted in the external leak of any radioactivity.
Since all of the required preparations have been made, the reactor will be shut down tomorrow and work will begin on replacing the relevant valve gasket.
Assuming the work proceeds according to plan, the reactor is scheduled to be restarted on February 19 and adjustment operations resumed.
*1: Regulated operations at a rated heat output of approximately 1.3 million kW with a pressure plate installed.
*2: Extraction steam check valves are installed to prevent the backflow of extracted steam (vapor) when the turbine is tripped, etc.
Extracted steam is vapor supplied to the feed water heater from the high-pressure turbine and low-pressure turbine to improve the heat efficiency of the plant.
*3: Gaskets are parts attached to the flange joints to provide them with air-tightness.
Hamaoka No. 5 Reactor System Overview
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