Can a semiconductor device discharge power capacitors
To discharge a 5000 uF capacitor in 2 seconds you need a resistor of about 400 Ohms, RC = 2.

200 V through 400 Ohms is just 0.5 A peak. Take 200 Ohms, so any 1-A transistor (in saturated mode) can discharge the capacitor with absolutely no problem, with little to no heat dissipation. The resistor might be some big one, with peak dissipation of 200 W. And the transistor should hold 200 V, which is no problem as well.

Addendum: To discharge the cap in 500 ms you need a 50-Ohm resistor, and a 4-A transistor. If you have a 20-mOhms 50-A transistor, you can do it with a 5 Ohm resistor. I would still insist on using a resistor, because it is much easier to have a resistor to dissipate power, than a transistor. I am lazy to calculate power, but I think this one will work: