Assuming ...

• File #1 always contains the same number of field per record
• You're using *NIX
• You only need to create an output file from the conjoined files

Then join(1) and sort(1) are your friends e.g.

sort file1 > file1.sorted
sort file2 | join -1 10 -2 1 file1.sorted - | tee file3
[download]

e.g. :

$ echo "SimpsonH","Homer","Simpson","NULL","648","0","218 555","Nuclea
+r Control","Nuclear Operator","111" > file1
$ echo "111","BurnsM" > file2
$ join -t, -1 10 -2 1 file1 file2
111,SimpsonH,Homer,Simpson,NULL,648,0,218 555,Nuclear Control,Nuclear 
+Operator,BurnsM
[download]

as required