Yes there is. If you look at the Trap Viewer on your Orion server (Start | All Programs | SolarWinds Orion | Syslog and SNMP traps | Trap Viewer), go to File | Settings. On the General tab there is a setting that allows you to retain trap messages for how many days. Your options are from 1 to 5000 days.
You should also look at the validity of the messages you are receiving.Do you need to reive them all ? What Severity do you really want ? You can create filter rules based on this in the trap Viewer also.
Thank you for the answers setting the days will help.
Also i created a filter to filter out those messages because they really were not necessary.