Under the terms of the Fuel Supply Agreement with BNFL, AGR fuel is ordered twice a year for delivery to site some 15-21 months later. Although this task is performed centrally and is the responsibility of the CEGB’s Nuclear Operations Support Group (NOSG), individual stations estimate their anticipated needs by relating declared generation capability in the months ahead to the fuel cycle. The AGR can only continue to generate maximum power for two or three months without refuelling and therefore, as insurance against any interruptions which may occur to steady fuel supply, an extra ‘contingency allowance’ is built into the fuel order which guarantees a few months’ extra operational needs.

Road transport is used for the delivery of AGR fuel elements from BNFL’s Springfields works to the power station, whereupon the new fuel boxes (each containing 8 elements) are moved to the fuel store in a carefully controlled manner, according to the re­quirements of the relevant Criticality Certificates. As we have seen, the different parts of the fuel stores will each be covered by the requirements of Criticality Certificates, which wilt specify the necessary restric­tions and types of operation permitted as a conse­quence of Criticality Safety Assessments relating to the appropriate area. The certificates will state, for example, whether or not stacking of fuel boxes may take place and to what degree.