Yes. With CYA=240 ppm, you'd need a MINIMUM chlorine level of 12. If you leave it there, you'll need to dose to about 20-25 ppm 1x per week, and let it drop to 12 before redosing. With a little practice, you'd be able to work out 1x per week dosing.
CYA=240 is a perfectly acceptable level to ME, but not to all the moderators here. Current recommendations are about 50 ppm for general use; 80 ppm for SWCGs, and 150 ppm if you are frequently gone and need to set up 1x per week treatment.
With a 25K gallon pool and CYA=240ppm, you'd need to drain 190/240 x 25K gal, or 19,000 gallons in order to be at 50 ppm when you've refilled. That's what most folks here will tell you do do, and it's what I would have recommended, 2 years ago.
What I currently would recommend is this:
1. Switch to a non-stabilized form of chlorine -- bleach, cal hypo or SWCG (If you need help on sources, let me know)
2. Add borax to the 60 ppm level (24 boxes of 20 Mule Team borax + 7 gallons of muriatic acid)
3. Let your CYA drop over the next few years.
4. Add chlorine 1x per week.
Going that route will give you extremely stable chemistry at very low cost, and you'll only have to dose 1x per week. If you have a sand filter, and use cal hypo -- I'll need to give you special instructions -- you will end up with VERY clear water.
If you do NOT want to switch to a non-stabilized form of chlorine, I'd recommend draining the pool completely since your stabilizer will start to rise as soon as you start adding chlorine.