Both of those have solutions: natural circulation, and turbo-electric drive. Natural circulation is seen on the Ohio class submarines[0], in which the heat gradient inside the reactor is enough to cause it to circulate without powering a pump to move it around. It only works well at low power, but if you're trying to make a good imitation of a hole in the water, that's enough. And it's not like the Gotland-class is any better at going fast.
Turbo-electric propulsion was seen on the USS Tullibee[1]. It definitely was an advantage, in terms of making the submarine quieter. But it had a disadvantage in being heavier than the machinery required for geared drive.
And the USN wants nuclear submarines. A Gotland had a pair of 75kW generators onboard for power/propulsion. A S9G reactor drives a 30MW pumpjet on a Virginia class. SSNs can go faster when necessary, and have more power available to run all their systems.
[0] https://en.wikipedia.org/wiki/S8G_reactor [1] https://en.wikipedia.org/wiki/USS_Tullibee_(SSN-597)