The Northern fleet runs a number of service ships that reload and unload nuclear fuel at sea as well as transport radwaste and spent nuclear fuel (SNF) back to harbour. A number of these ships were used for collecting radwaste and dumping at sea prior to the London Convention of 1993. The Northern Fleet has six tankers liquid radioactive waste (LRW) and seven that are used for transporting SNF. A number of the vessels are also used as storage points for both LRW and SNF.