is granted at the same time as Section 2 Consent. However, the Secretary of State may attach conditions, as he thinks appropriate, in regard to the planning approval.

Following receipt of Section 2 Consent and financial sanction, the CEGB proceeds with the design and con­ struction of the project. Figure 1.3 shows the typical timescale for power station planning and early con­ struction.

An important part of the investigation programme is consultation with Ministerial and Local Authorities and other statutory bodies such as Water Authorities. As part of the procedure for ensuring that all parties are fully aware of agreements which have been negotiated and which must be observed during the station design and construction period, a document called ‘Station Development Particulars’ is issued, which records all discussions and agreements with parties and also con­ tains a schedule of statutory consents which must be obtained.

The Station Development Particulars also contain a technical section dealing with the transmission connec­ tions and parameters of the main plant, particularly the generator transformer, so that they are properly matched to the transmission system. The details cover matters such as power factor, synchronous impedance, frequency regulation, the dynamic response of the unit to change in load demand and guidelines on the elec­ trical auxiliary system to ensure that this is a reliable network.

Site selection and investigation

2Site selection and investigation

2.1Basic site requirements

A power station is simply a factory for the conversion of the energy stored in the fuel into electrical energy. The basic requirements for a power station are, there­ fore, similar to those of any other factory:

•A supply of raw material at a competitive cost (fuel).

•Access to the markets for its products (transmis­ sion).

•A labour force of the size and quality required.

•Means of disposal for any trade effluent or by­ product.

•Land for construction and operation.

The raw material from which electricity is made in a thermal power station can be coal, oil, uranium or natural gas. Electricity, the main product, has its own access to centres of consumption through the transmis­ sion and distribution system. By-products are ash or irradiated uranium fuel elements and the economic disposal of the former is often a major consideration. The trade effluents are the large quantities of heat, the disposal of which generally requires very large quanti­ ties of water which, for cost reasons, must be available close to the site. The products of combustion, in the

Power station^siting arttb-site layout

form of large volumes of flue gases, must also be dispersed without contravening the national clean air policy or causing atmospheric pollution.

The main technical requirements of sites for nuclear and coal-fired stations of the size being considered currently are summarised in Table 1.1.

Chapter 1

2.2 Area of search for initial site selection

In densely-dcvelopji countries like England and Wales, suitable pow^station sites are difficult to find. Many of the best sites have already been used for one

purpose or another and more and more of the undevel­ oped areas are being conserved. In fact some 12% is built on, while over 40% is given statutory protection; on the coast, the respective figures are 25% and 60% (see Fig 1.4). Nevertheless the CEGB must be able to

Further limitations are imposed on the CEGB in rts search for suitable sites by the lack of actual "empty spaces" available. As this map illustrates, much of the land which meets the technical requirements is statutorily protected • (or example m the form of National Parks. Areas ol Outstanding Natural

Beauty and National Nature Reserves. The difficulty can be only partly overcome by re-using existing sites.

BUILT UP AREAS

NATIONAL PARKS

AREAS OF OUTSTANDING BEAUTY

GREEN BELT

FOREST PARKS

AREAS OF GREAT LANDSCAPE,

HISTORIC. OR SCIENTIFIC VALUE

Site selection and investigation

meet the need for new stations as foreseen by its estimates of future demand.

The considerable length of time that is required to plan and construct a station and the regular revision of future demand estimates means that it is wise for the