Hinkley Point, reactor

Fig. 4. A typical advanced gas-cooled reactor graphite core (Hinkley Point B under construction) [11].

Two members of the Working Group visited Hinkley Point B on 12-13 February 1987 to study some of the normal and emergency operational procedures on an Advanced Gas-cooled Reactor station. 

This expierience has demonstrated Hinkley Point B s dDility to obtain necessary in-reactor insp>ection information in the above dome region in the absence of man oi-try. 

A manipulator display and guidance system has been successfully developed and commissioned on the Hinkley Point B Above Dome Manipulator and used without an in reactor observer. 

At time of writing, Electricite de France (EDF) is about to make a decision to finally commit fuUy to the constraction of a large new twin pressurized water reactor (PWR) at Hinkley Point, Somerset, in the UK. The plant will be two European Pressurized water Reactors (EPRs), designed by Areva and built by EDF. Similar plants are already in construction at Olkiluoto (Finland), Flamanville (Normandy, France), and Taishan (China). 

Hinkley point is located on the north coast of Somerset on the Bristol Channel, some 8 miles north-west of Bridgewater. The A station consists of two reactors housed in steel spherical pressure vessels of 67 ft diameter, made of plates 3 in. thick. Each reactor has six boilers. Generating plant consists of six 3.5 MW turbo alternators and three 33 MW turbo alternators to provide auxiliary supplies. Total output of the station is 500 MW, which is fed into the 75 kV Supergrid system running between Melksham and Taunton. 

HAY, J. D. and EADIE, D. McD. The prestressed concrete pressure vessels for Hinkley Point B and Hunterston B . Paper No. SM.ll 1/31. Symposium on Advanced and High Temperature Gas-cooled Reactors. Jillich, Germany, October, 1968. 

The first two of the AGR stations, Hinkley Point B and Hunterston B, came on line in 1976. The success of the program will depend on the avoidance of further corrosion or vibration damage, particularly in the extremely complicated region above the reactor core, where repair work would be exceptionally difficult. 

Some industrial examples (Table 2) demonstrate these differences between gas-cooled and liquid-cooled nuclear reactors. The General Atomics gas-cooled HTGR (the GT-MHR) has a AT across the reactor core of 359 C, while the British Advanced Gas-Cooled Reactor (Hinkley Point B) has a AT of 355 C. Liquid-cooled reactors t5q)ically have much-smaller temperature increases across the reactor core. The Point Beach pressurized-water reactor (PWR) has a AT across the reactor core of 20 C, while the French liquid-metal fast reactor (Super Phenix) has a AT of 150 C. A liquid-cooled reactor can deliver all of its heat with small temperature differences (20 to 150 C) between (1) the hottest temperatures in the reactor coolant, piping, and heat exchangers and (2) the maximum temperature of the chemical reagents in the H2 production facility. 

Although Hinkley Point was the CEGB s third reactor, it too suffered from a redesign of the core following the Windscale incident, delaying the project by around a year or so. Also as a consequence of the incident, the CEGB decided that reactor number 2 should be fitted with a great deal more instrumentation than would be necessary... 

A follow-up paper a little later in 1967 tried a similar exercise, but included the tender price for the HinWey Point AGR bid for comparison. Hinkley B had two reactors each of 625 MW (E). The cost of the 350 MW SGHWR was scaled up to an equivalent size. The Hinkley B tender price was quoted at 75.44 million whereas the equivalent SGHWR was costed at 50.13 million. Hinkley B would cost very much more than its tender price, but with the inflation of the 1970s it would be difficult to compare the final cost with the tender price. 

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