UHF Changes in Pittsburgh?

I recently spotted an entry to the Radio Reference database showing a "new" federal UHF trunked system. You can check out the entry here:

http://www.radioreference.com/apps/db/?sid=7445

The system is not new, and for you Fed Files readers, it appeared in the March, 2006 column. It belongs to the  National Nuclear Security Administration Bechtel Bettis Navy Reactor Facility in West Mifflin, PA a suburb of Pittsburgh. You can see more about this facility at these web sites:

http://www.nnsa.doe.gov/siteoffices.htm#pittnaval 

http://www.bettislab.com/

The entry in the Radio Reference database indicates that they may have changed some frequencies in the system since I last monitored it. Originally I had it using these channels:

406.9750 MHz

407.1375 MHz

407.3875 MHz

407.7875 MHz

408.1750 MHz

New new listing has added a frequency of 406.3375 MHz and deleted the 407.1375 MHz channel. Probably some additional re-shuffling of the federal UHF assignments.