The Ferranti mainframes mentioned in the article are probably Argus 700 machines developed in 1968/9 [1] Amazing that such tech was still running important infrastructure only a decade ago.
They absolutely are Argus 700's, and a lot of the design of the systems is in the public domain.
> The computer system consists of a network of computer nodes, based on the Ferranti Argus 700 range of computers, assigned to each reactor unit, except where common station facilities are required. For each reactor unit, the computer system provides both data processing and automatic control functions. For essential data capture, control and display to the CCR operators, the processor hardware is duplicated. These are termed Level 1 systems and are shown in Figures 1 and 2. Single
processor systems which collect data not considered essential for continued unit operation are termed Level 2 systems. Figure 3 illustrates the Level 2 computer system for both units. Torness NFS probably has the most complex computer configuration of any operating nuclear power station. The auto control "supersystem" consists of, per reactor, ten input multiplexing computers ("muxes"), eleven control computers (CCOI, CCO2 to CCI 1) and a dual online/ standby supervisory computer ("CS"). Each of these computers is a node in the hierarchical control supersystem shown schematically in Figure 2.
The training simulators used custom hardware from Marconi Simulation as well - a long long time ago I didn't get to job to work on them at Torness.
Mind you I did end up on an academic project that included modelling of Hunterston, so I got the "behind the scenes" tour there that Charlie got for Torness.
The Project Manager from Scottish Nuclear had worked on the construction of Torness and he lots of interesting stories.
1. http://www.computinghistory.org.uk/det/16225/Ferranti-Argus-...