The pioneering Compensation Agreement between BNFL and its signatory Staff and Trade Unions was introduced in 1982, initially limited to cases where a cancer had caused death. In 1987 the Agreement was extended to include cases where cancer had developed but not caused death and the United Kingdom Atomic Energy Authority joined with BNFL in operating the Agreement. It was originally recognised that the technical basis of the Agreement would require review, in order to benefit from the experience gained during the initial period of operation of the scheme and to permit the incorporation of revised estimates of the effects of ionising radiation. This review led to the revised `Technical Basis' described in this paper. Compared with the previous Technical Basis, it is expected that the revisions made will result in approximately twice as many awards being made with a shift in the distribution of awards in favour of the older age groups. The review is retrospective in that all previous claims will be re-assessed under the new Technical Basis and new or increased awards made under the terms of the Agreement.