Progress Energy will blast the emergency sirens at the Shearon Harris nuclear plant Tuesday in a quarterly test of the plant's public warning system.

The 83 sirens will be sounded at full volume for about three minutes sometime between 10 a.m. and 11 a.m. The tests are conducted every three months.

Progress operates 83 sirens, mounted on 50-foot towers, within the 10-mile Emergency Planning Zone surrounding the nuclear plant located in southwestern Wake County. The area includes the towns of Apex, Holly Springs, Fuquay-Varina, Moncure and New Hill.

Remain Calm.

All is well.

If you're on the Duke University campus Wednesday or Thursday, you may be startled by a blaring emergency alarm. University officials ask that you do NOT call 911; they're simply testing the new emergency response system they purchased recently.

The tests will be conducted Wednesday from 2 to 4:30 p.m., and Thursday from 8 a.m. to 4:30 p.m.

Sirens will sound intermittently. If you're outside on campus or close to it you may hear loud tones and live and recorded messages.

Fear not, Dookies: That blaring siren you may hear this month is only a test.

Duke this summer is joining a number of universities installing outdoor alarm and alert systems to use in case of campus emergency - a response to last year's massacre at Virginia Tech. 

The university has been installing the systems in recent months and will be testing them in July. Aaron Graves, Duke's security chief, told me this week the specific times of the tests aren't yet known, but will be done throughout the month.