unable to stop powernap 2.21 Ubuntu 16.04.1

[David Partridge]

root@Charon:/var/log# powernapd
root@Charon:/var/log# cat powernap.log
2016-07-30_15:34:19 INFO Starting powernap
root@Charon:/var/log# ps -ef | grep powernap
root 12398 1 1 15:34 ? 00:00:00 /usr/bin/python /usr/sbin/powernapd
root 12602 4695 0 15:34 pts/1 00:00:00 grep --color=auto powernap
root@Charon:/var/log# kill 12398
root@Charon:/var/log# cat powernap.log
2016-07-30_15:34:19 INFO Starting powernap
2016-07-30_15:34:46 INFO Stopping powernap
root@Charon:/var/log# ps -ef | grep powernap
root 12398 1 0 15:34 ? 00:00:00 /usr/bin/python /usr/sbin/powernapd
root 12732 4695 0 15:35 pts/1 00:00:00 grep --color=auto powernap
root@Charon:/var/log#

As you can see it logs a message saying "Stopping powernap when sent a signal, but doesn't go away!

Cheers
Dave