Hi Hannah
bpdu protechtion or loop protect unable prevent broadcast packet
loop protech prevent loop on your local network
bpdu protech prevent connection unauthorized (edge switch ,access point,router etc.) network device on your local network.
if you want prevent excessive broadcast packet
you can use broadcast limit command
ProCurve Switch 3500-24(eth-20)# broadcast-limit
<0-99> Enter an integer number for the 'broadcast-limit'
command/parameter.