I tried to find any anti-nuclear spin (no pun intended) there, but couldn't find any.
The fact that your spin-detector can't sense anything from the summary is indicative of greater problems.
But I digress. Let's begin with the title.
Another Crumbling Reactor Springs a Tritium Leak
Of the seven words in that title, three are designed to create a perception of the situation that is far worse than reality.
"Another": indicating more than one, or the latest in a series, or a connection to a greater ongoing situation. This is a spin word because it gives the impression that tritium leaks are special events that deserve special attention. This is not true. Reactors have been known for a very long time to create tritium and leak it, sometimes deliberately. CANDU reactors release tritium into the surrounding environment as a consequence of their design. They are allowed to do this because such leaks are not dangerous.
"Crumbling": indicating an advanced state of disrepair and decrepitude, a state of 'going to pieces', extreme unsoundness in structure or the inability to support it's own weight. This is a spin word because only a technical, literal definition of "crumbling" can apply to the reactor in question, the same definition that can be applied to anything, because everything not being created is in a state of entropic decay.
"Springs": indicating a sudden or forceful event. This is a spin word because it gives a false picture of what is plausibly taking place. Many reactors leak tritium as it diffuses through concrete and steel or in their cooling water. Any sudden or forceful leak of tritium would most likely be accompanied by a sudden and forceful leak of super-heated steam, which obviously hasn't happened.
Onto the summary.
"The decrepit nuclear reactor Vermont Yankee has sprung a radioactive leak similar to those at other poorly run reactors in Illinois (Braidwood, Byron and Dresden), Arizona (Palo Verde), and New York (Indian Point).
"Decrepit", "sprung" and "poorly run" are all loaded words. They make unsupported judgments about the reactor in question. The supposed problem is then also attributed to a number of other reactors the reader may or may not know about. This sentence assumes a problem and is constructed to make it appear to be widespread.
The use of the words "radioactive leak" is also spin, since anything radioactive escaping from anywhere can be counted. Dropping an ionizing smoke detector on the ground could be described as a "radioactive leak".
Greenpeace noted 3 years ago that radioactive tritium leaks even threaten Champagne from France.
This is spin, but it relies on the reader taking Greenpeace to be in a position of authority to make such judgments.
Tritium and its decay product helium 3 are incredibly valuable and there is currently a shortage of helium 3.
This is the only non-spin sentence in the summary. It may or may not be factually correct, I don't know, but it's stated as a fact and does not contain any loaded language I can see.
What, besides shutting down leaky old nuclear plants, could be done to better control release of tritium into the environment?"
The spin here is the loaded question which implies that the current release of tritium into the environment is a problem worthy of attention and further control.
So, yeah, there's the anti-nuclear spin. Lots of loaded words, ill-defined terms, misleading wording and an appeal to authority thrown in to boot.