The initial turbine non-nuclear steam roll-up is an important test during nuclear power plant startup. The purpose of the test is to discover and solve turbine problem before reactor achieve critical. The benefit of this test is milestone may be shorter and save time. Use AP1000 equipments design parameters to calculate the basement of this test, by the way, we can find a safe method to startup.
In this test, the heat is produced by reactor coolant pumps and PZR heaters. During roll-up, to avoid critical zones of turbine and reduce thermal stress, we hold on some speed points. At low speed period we can make up heat to make sure we can achieve the purpose of this test. So the calorimetric balance between primary side and second side is very important.
Non-nuclear steam has many benefits for nuclear power plant startup. First, the secondary loop completes build before the primary system, but as one of the most important equipments, turbine must be examined to make sure it can roll-up and operation without no disease, so before primary system equipments installation finished we can save lots of time to solve turbine problems; the second one, during this duration, all of equipments of primary system can perform their function in the first time, we also make sure system function can perform correctly and timely. So, as a big picture, the milestone of startup can be shorter by replace nuclear steam rolling-up the turbine.