When I start to turn the wheel to the right and the car starts to move, I get a repetitive clunking sound. It isn't the brakes, but it sounds expensive. any ideas?

It's a clicking sound and the boot is torn.

The bad news - it's the CV joint
The good news - this is a pretty easy repair
fcpgroton has axles for $105 ready to go, new
boots and all.
http://www.fcpgroton.com/volvo850driveline.htm

Check out the below link from bay 13
http://www.volvospeed.com/Repair/FWDbearingHub.php

while the instructions are for a wheel bearing
the first steps are the same for the axle, then
take the axle support mounting bolts out
and the axle should come out pretty easily.
Slide the new one in and proceed in the reverse
order.

Good luck with it!
--
1990 240DL - 209K, 1989 Ranger 241K, Gone but not forgotten 1994 855

Turn the car to the right under light power
does it go click, click, click.
Under heavy acceleration on a right turn
is the click, click, click louder?
Does it speed up as the car accelerates?

This sounds like the symptoms of a failing
constant velocity joint to me. Jack up the
car and inspect the boot of the outer CV
joint on the right side. Still intact?

Is it a click or a low pitched clunk?
--
1990 240DL - 209K, 1989 Ranger 241K, Gone but not forgotten 1994 855

This is a well known problem and will require some grease on the wheel stops.
--
1998 Volvo S70