See explanation

See explanation.

The answer to this relies on your definitions. The answer is yes but I will dig into it a bit more.

If you are interested in the SPEED of the object, the speed remains constant in uniform and so you might argue that it is not .

However, the definition of acceleration is the rate of change of VELOCITY so we need to consider the direction of motion as well as the magnitude of the velocity.

As an object travels in a circular path, it is constantly changing direction. This means that the velocity is changing (if you resolve vertically and horizontally you will see this). If velocity is constantly changing, this must mean that the object in uniform circular motion is accelerating.

But is the acceleration constant?

The force acting on the object is constant in uniform circular motion and equal to ##mv^2/r## (This only need the magnitude of the velocity, the direction is not important as the velocity is squared)

If we assume that the mass is constant:

##a = F/m = (mv^2/r) /m => a = v^2/r##

As the velocity is squared, the direction has no effect so this number will always be constant as the magnitude of velocity remains the same throughout, therefore acceleration is constant in uniform circular motion.