Hen party

The title “The Bachelorette Reunion: The Biggest Bachelorette Reunion in Bachelor History Ever!” may just be poking fun at the franchise’s flair for hyperbole, but the two-hour special is more than prepared to back up its claim with appearances from 12 former bachelorettes, including Minnesotan Becca Kufrin.

7 p.m. KSTP, Ch. 5

Darkness falls

Grim only begins to describe the tone in “Chernobyl,” a five-part miniseries on the 1986 nuclear accident and how Russian bureaucrats made matters even worse. The details behind the disaster get a little wonky, but even viewers that got C’s in high school chemistry will appreciate the urgent performances from Jared Harris, Emily Watson and Stellan Skarsgard.

8 p.m. HBO

I’ll drink to that

“State of the Union” may have a unique format — 10-minute episodes that revolve almost solely around a husband and wife catching a quick drink before their weekly counseling sessions — but the series resonates because of ol’ fashioned, witty dialogue penned by Nick Hornby (“High Fidelity”). Stars Rosamund Pike and Chris O’Dowd may not be the ideal married couple, but they’re just the kind of smart company you’d hope to run across at your local pub.

9 p.m. Sundance

Neal Justin