STUDI PENENTUAN TITIK KRITIS BEJANA TEKAN REAKTOR PWR TERHADAP TEMPERATUR DAN TEKANAN DENGAN SIMULASI MSC NASTRAN
By : PRIMA WIJAYA KEDOH
Faculties : Fakultas Teknik
Department : S1 Teknik Mesin
This research has analyzed temperature and pressure effect on the reactor pressure vesselís top wall. Itís very important, due to itís function as radioactive materials barrier during nuclear reaction and also is one of the most critical structure in reactor safety priority. Most common problem that usual appears were, how much temperature and pressure effect to reactor pressure vesselís wall. This purpose was characteristic and critical point of the reactor pressure vesselís wall, in order to satisfy safety based on ASME III standard. Simulation method with MSC Nastran software has been used, include pre-process by MSC Patran software: 1) geometry design of reactor pressure vessel as input, 2) mesh geometry model, 3) insert material properties SA533 grade B1, 4) boundary condition load or define constraint and load, solver: load and constraint by MSC Nastran software and post-process: resulted by MSC Patran software. While applied three reactor condition: design condition as the highest operation limit at temperature 343.33?C and pressure at 17.1 MPa, normal operation condition at temperature 288?C and pressure at 15.51 MPa and hydrostatic test condition to check leakage on the reactor pressure vessel at temperature 48?C and pressure at 21.37MPa. Independent and dependent variables were temperature, pressure, reactor pressure vessel type and properties material also von mises stress. Simulation has shown characteristic and critical point result of reactor pressure vessel due to the temperature, pressure and combination load both temperature and pressure. The highest Von mises stresses (?í) were around nozzle inlet and nozzle outlet area. Due to temperature load at design condition was 38.5 MPa, at operated condition was 31.7 MPa and at hydrostatic tested condition was 2.31 MPa. Due to pressure load at design condition was 413 MPa, at operated condition was 375 MPa and hydrostatic tested condition was 516 MPa. Due to combination load at design condition was 409 MPa, at operated condition was 371 MPa and at hydrostatic tested condition was 516 MPa. Von mises stress (?í) result compared against allowable stress due to temperature load at design condition was 5.57%, at operated condition was 4.59% and at hydrostatic tested condition was 0.33%, due to pressure load at design condition was 59.85%, at operated condition was 54.34% and at hydrostatic tested condition was 74.78%, due to combination load at design condition was 59.27%, at operated condition was 53.76% and at hydrostatic tested condition was 74.78%. Von mises stresses (?í) from three simulation condition results were still qualified, where the allowable stress (?s) was 690 MPa. Based on analyzed result, can be concluded that reactor pressure vessel was proper to use up to highest design condition at temperature 343.33?C and pressure at 17,1 MPa. Besides that, used MSC Nastran software simulation was very effective and efficient in nuclear reactor pressure vesselís ability analyzed, which is dangerous and difficult enough.
Keyword : Pressure vessel, Reactor PWR, Von mises, Simulation, MSC Nastran.