Cause Analysis of the Acetylene Produced in Main Transformer Phase B in LNPS

In the analysis of main transformer phase B of unit 2 in Ling’ao Nuclear Power Station（LNPS） by chromatography,acetylene was found.In order to carry out the inside check,the main transformer had been stopped and restored after necessary maintenances.But shortly,0.86 μL·L^-1 acetylene was measured,so the transformer had to be replaced for the safe operation in a new cycle.The paper analyzed the most possible causes based on the check results after lifting the tank of transformer,and the new corrective measurements and the considerations were provided to improve the transformer reliability.