Answer:
Yes (but not how you think)
Step-by-step explanation:
I'm assuming that you mean if nuclear fusion, where two atoms (in this case mostly hydrogen) fuse into one heavier atom, and release a lot of energy.
However, fusion happens when there is a tremendous amount of pressure or heat. This is found in the core
The 5 million degrees is found on the surface of the sun, but at the core, it is at 15 million degrees.
In addition, the pressure is so extreme that if forces atoms to become one, despite the fact they don't like being together (try finding 2 strong magnets and hold them so that they try to repel each other and try and make them touch, it's hard! Now imagine having to put a million of times the amount of strength!)
So, the sun is capable of nuclear fusion, but at the core, where it is 15 million degrees!
(fun fact: scientists are trying to build "mini-suns" called Fusion reactors to try and harvest the power of the sun!)