During the start-up and shutdown process of a 1 000 MW nuclear power unit

multiple equipment failures and unplanned downtime events related to the moisture separator reheater(MSR) system occurred.Analysis on the operating data and operating failures process shows that

the operation of MSR system has great influence on safe and stable operation of the turbine. The reheat steam temperature control mode of the MSR system needs to be optimized and the effect of over-limiting temperature variation of reheat tube plate on equipment reliability need to be evaluated. Because the drastic change of steam parameters is likely to cause deformation of the high/intermediate pressure cylinder body during the unit start/shutdown and low load operation

it is necessary to focus on the problem of cylinder deformation and rubbing caused by improper control of temperature control for MSR reheat steam.