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jrflowersyesterday at 6:17 PM2 repliesview on HN

> The Naval Nuclear Propulsion Program has over 7,500 reactor years of cumulative reactor operation, and nuclear powered ships have steamed over 175 million miles. Since the inception of the program, there has never been an accident involving a naval reactor nor a release of radioactivity to the environment which has adversely affected public health or safety.

https://www.nr-ha.org/history


Replies

crotetoday at 12:32 AM

The program led to the Three Mile Island accident, which is one of the largest releases of radioactivity in US history.

Naval reactors are inherently safer due to their small size and unlimited supply of cooling water. A meltdown is virtually impossible, worst-case scenario you could always use a firehose and a diesel pump to inject sea water into the reactor. On the other hand: you really don't want to overfill the reactor: a naval reactor "going solid" rips itself apart, killing the ship.

Commercial reactors are the exact opposite. Overfilling them is not a huge deal as there are plenty of ways to relieve pressure, but underfilling them can easily lead to a meltdown. Even after shutdown it needs active cooling for a decent while to prevent residual decay from overheating it.

The TMI reactor operators were trained on naval reactors, but they were operating a commercial reactor. During the incident they were too busy trying to prevent it from overfilling to notice that it was actually cooking itself dry - so they intentionally shut down the emergency cooling system!

So no, saying that the Navy Nuclear Propulsion Program has led to zero accidents is both wrong, and completely irrelevant to the subject here.

lolcyesterday at 8:02 PM

> ... which has adversely affected public health or safety.

Why would they tack that on at the end of a very long sentence? Because they don't want to talk about the loss of USS Scorpion. They mention the sub once on the whole page and even misspell it as "Scorpian". Would not trust them as a source.

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