Cosmogenic nuclides such as 14C, 10Be, and 36Cl are produced by cosmic rays in the atmosphere. Extreme solar energetic particle (SEP) events can produce cosmogenic nuclides in amounts that greatly exceed the background level. Several candidates of extreme SEP events have been reported in 14C, 10Be and 36Cl data, since the discovery of the first SEP event candidate in 774 CE. We continue to search for past extreme SEP events mainly using 14C data over the last ~10,000 years. In this presentation, reported SEP event candidates in cosmogenic nuclide data and new event searches will be introduced.