Cursor Tuning Help!

This cursor is processing one row per second, all it is doing is appending a value to a column. There are 847,000 rows and I can't leave the query to run for 10 days! help!

CREATE procedure [dbo].sp_USR_TEMP_SESSIONAL_ATTENDANCE_APPENDasbegin DECLARE @I_UPN varchar(13) DECLARE @I_SURNAME varchar(50) DECLARE @I_FORENAME varchar(50) DECLARE @I_DOB datetime DECLARE @I_GENDER varchar(1) DECLARE @I_LEA varchar(3) DECLARE @I_DFES varchar(4) DECLARE @I_ATTEND_YEAR varchar(4) DECLARE @I_WEEK_BEGINNING datetime DECLARE @I_ATTEND_CODES varchar(14)declare @cnt intset nocount ondeclare cur CURSORfor select upn, surname, forename, dob, gender, '353' as lea, dfes, attend_year, week_beginning, attend_codes from tmpATTEND_IMPORTfor read onlyopen curfetch from cur into @I_UPN, @I_SURNAME, @I_FORENAME, @I_DOB, @I_GENDER, @I_LEA, @I_DFES, @I_ATTEND_YEAR, @I_WEEK_BEGINNING, @I_ATTEND_CODEStruncate table tmpATTEND_IMPORT_APPENDEDwhile @@fetch_status = 0 begin set @cnt = (select count(*) as cnt from tmpATTEND_IMPORT_APPENDED where upn = @I_UPN and surname = @I_SURNAME and forename = @I_FORENAME and dob = @I_DOB and gender = @I_GENDER and lea = @I_LEA and dfes = @I_DFES and attend_year = @I_ATTEND_YEAR)if @cnt = 0 insert tmpATTEND_IMPORT_APPENDED( upn, surname, forename, dob, gender, lea, dfes, attend_year, week_beginning, attend_codes) values ( @I_UPN, @I_SURNAME, @I_FORENAME, @I_DOB, @I_GENDER, @I_LEA, @I_DFES, @I_ATTEND_YEAR, @I_WEEK_BEGINNING, @I_ATTEND_CODES)else update tmpATTEND_IMPORT_APPENDED set attend_codes = attend_codes+@I_ATTEND_CODES where upn = @I_UPN and surname = @I_SURNAME and forename = @I_FORENAME and dob = @I_DOB and gender = @I_GENDER and lea = @I_LEA and dfes = @I_DFES and attend_year = @I_ATTEND_YEARfetch next from cur into @I_UPN, @I_SURNAME, @I_FORENAME, @I_DOB, @I_GENDER, @I_LEA, @I_DFES, @I_ATTEND_YEAR, @I_WEEK_BEGINNING, @I_ATTEND_CODESendclose curdeallocate curendGO