09 فروردین 1403
مهدي ثقفي

مهدی ثقفی

مرتبه علمی: استادیار
نشانی: آذربایجان شرقی - بناب - دانشگاه بناب
تحصیلات: دکترای تخصصی / مهندسی هسته ای
تلفن: 041-61811621
دانشکده: دانشکده فنی و مهندسی
گروه: گروه مهندسی مکانیک

مشخصات پژوهش

عنوان
Analysis of Thermohydraulic Limits during WWER-1000 Nuclear Power Plants Heat-up Using RELAP5 System Code
نوع پژوهش مقاله ارائه شده
کلیدواژه‌ها
Heat-up, WWER-1000, RELAP5, Thermohydraulic
پژوهشگران مهدی ثقفی (نفر اول)، جلیل جعفری (نفر دوم)

چکیده

Plant heat-up is a process which all operating systems such as primary coolant circuit, pressurizer, primary and secondary sides of the steam generators and etc. are transferred from a cold shutdown to a hot standby status. During plant heat-up, some thermohydraulic limitations such as maximum and minimum allowable pressure and maximum rate of increase in pressure and temperature which are recommended by plant commissioning program and NPP safety related documents should be considered. Maximum allowable pressure prevents brittle fracture in reactor vessel, Minimum allowable pressure in the inlet of the reactor coolant pumps (RCPs) prevent pump cavitations and maximum allowable rate of increase in temperature and pressure respectively prevent thermal and mechanical shocks. Thus, tuning pressure and temperature increasing rates during plant heat-up is important from plant safety point of view. The RELAP5 system code was used to model and analysis the behavior of WWER-1000 plants during heat-up. In plant heat-up, at first the primary circuit pressure increases by injection of N2 gas into pressurizer in order to providing minimum required NPSH for operation of the RCPs. After short time RCPs are turned on to operate which increase the primary coolant circuit temperature through friction losses. At a time which specified by heat-up procedure the pressurizer heaters are turning on to increase the primary circuit pressure. Heat transfer from primary to secondary side in the steam generators causes increasing of the secondary side temperature and pressure. Temperature and pressure of primary and secondary circuits increase until plant reaches to hot standby condition. The results show that the thermohydraulic parameters during plant heat-up are in an acceptable range and have a good agreement with available data in technical documents.