I'm assuming you're referring to the series The Heavy Water War?

Anyhow, the series is correct in that the USAAF did indeed carry out a series of bombing raids against the Vemork Hydroelectric Plant after Operation Gunnerside, the follow up to the failed Freshman operation, had taken place. Operation Gunnerside, which took place in February 1944, was ultimately successful in getting a commando team into the plant and sabotaging it's heavy water production equipment as well as the entire supply of heavy water produced at the plant during the occupation.

While the damage that resulted from the Gunnerside raid was significant, it wasn't irreparable, and the Germans were eventually able to get the plant up and running again a few months after the raid took place.

The Allies, relying on local intelligence as well as aerial reconnaissance, determined that a follow up commando raid would likely fail due to increased security at the plant after the success of Operation Gunnerside. So nine months after the Gunnerside Operation, the USAAF conducted three daylight raids against the plant. The first heavy air raid dropped a payload of about 711 bombs, though the majority missed the plant itself. Follow up raids took place on the 16th and 18th of November, which were more successful in dropping their payloads onto the plant. While the bombing itself did not completely destroy or impede the Germany's ability to produce heavy water at the plant, it did convince them that it was time to move the critical heavy water production equipment and stockpiles to Germany.

In February 1944, the Germans attempted to ship the remaining heavy water supply to Germany. However, the British, having learned of the heavy water shipment, dispatched a commando who had remained in Norway to intercept the shipment and ensure that it did not reach Germany. The commando was successful, as he and his team were able to successfully plant explosives that sank the ferry that was carrying the heavy water shipment bound for Germany as it crossed Lake Tinn.

As far as how accurate the series is, I'd say overall it does a pretty good job of getting the majority of the facts right but that it does occasionally suffer from events being overly dramatized or embellished for the sake of drama. Most of the criticism I've seen is levied at how the series handled it's depiction of Heisenberg, as well as how antagonistic the USAAF General is towards the Norwegians and the British when they push back on the initial attempts to carry out bombing raids rather than commando raids.

Sources:

The Heavy Water Raid: The Race for the Atom Bomb 1942–1944 by Poulsson Jens-Anton

The Making of the Atomic Bomb by Richard Rhodes

Assault In Norway: Sabotaging the Nazi Nuclear Program by Thomas Gallagher