Nuclear War

Tritium "EXIT" signs are radioactive, which is what makes them glow without plugging them in...

From the Nuclear Regulatory Comission Website's Tritium Fact Sheet:
"Tritium is a radioactive isotope of hydrogen that typically is produced in nuclear reactors or high-energy accelerators. It decays at a rate of about five percent per year (half of it decays in about 12 years). Tritium’s decay makes it necessary for routine replenishing in U.S. nuclear weapons. The United States has not produced tritium since 1988, when the Department of Energy's (DOE's) production facility site in South Carolina closed. Immediate tritium needs are being met by recycling tritium from dismantled U.S. nuclear weapons. According to DOE, resumption of tritium production is essential for maintaining the U.S. nuclear weapons stockpile."

No mention of whether supplies for EXIT signs are running out at this time.

item 22, on the Berkeley City Council's Agenda for last Tuesday:

a. Phase-Out of Tritium Exit Signs, from: Community Environmental Advisory Commission (PDF, 92 KB)

The City Councill passed the above resolution on it's consent calandar (in other words, without debate) this week, along with the plan from the city manager to implement the recommendations:

Berkeley won't buy any new Tritium Exit Signs, they're gonna count all of the tritium exit signs that are in city buildings before November, and they're gonna train city employees how to recognize the particular signs and dispose of them properly. According to this company selling an alternative EXIT sign technology, most of the radio active signs end up illegally thrown out in the garbage.

All of this, by the way, has little to do with the real Tritium News of the day.: NRC to investigate tritium leaks at Indian Point, elsewhere

NRC on Tritium and the "leaks."