If you want to clear the log easily, enter the following in Windows Terminal:

wevtutil cl 'Microsoft-Windows-Windows Defender/Operational'

Hello Fred. Were you aware that you can limit the size of this event log? If you right-click 'Operational' (in the left pane) then select 'Properties' you can set the maximum log size.

You may want to include that in your post.

Thank you!