All defender go out evry round im plat 2 and dont like this kids style of play <| sep |> Yeah they need to clean this up . Separate it properly into each campaign by name , each coop commander , each MP race , and each arcade map obviously they can ' t show every arcade map in the settings so I guess access those from the arcade maps page in the arcade . <| sep |> Yeah you do ! I live in OT so the gurus are a convenient place when I need it , but Empire is right by Bull Moose so it ' s not bad . <| sep |> One of the concerns is with vessel Nil Ductility Temperature NDT . NDT is the point at which metal goes from ductile bendableflexible to brittle . If you ever look at the experiment where a banana is put in liquid nitrogen then shatters like glass , that ' s an extreme form of crossing the NDT point and what we are afraid of in the nuclear industry . The reference NDT is basically the actual NDT plus a safety margin . For my plant it ' s 70 degF , so we have a 70 degF margin on top of our actual NDT . We are never allowed to operate the reactor or pressurize it below RTNDT with some specific testing exemptions when we are in cold shutdown . A reactor needs to be above its RTNDT to pressurize the core . As the vessel ages and is embrittled by neutrons , RTNDT gets higher . It also rises as a result of thermal stressshock done to the core during transient operation , and partially as a result of chemical embrittlement . We measure RTNDT using test samples in the reactor which are periodically removed and destructively tested for their Upper shelf energy and NDT points . The other thing that is looked at now a days , is crack propagation . It ' s a matter of fact that micro cracks exist to some extent all over pressure vessels , especially in the nozzles and dissimilar metal welds . There are a number of ways to control this , and one of them is to ensure the injection of cold water is minimized when it does happen . So warming the ECCS injection temperature can help with these issues . The other thing it can help with is low temperature over pressure protection , and with stress on the vessel for events where the RCS goes water solid .