I want sincerelly to say thankyou all. All comments from you all have been helpful.
I omitted some information just to avoid a large post.

UPS is not a posibility. Data must be retained locally because of certification constraints.
Similar systems use NVRAM device (maybe through PCIe) mounted as a HD.

I was trying to preclude the use of such a device.
Thank you all again, this forum REALLY help.