…we now believe that the series ordering phase will begin in the earlier part of the next century… the development programme will be geared to this timescale… The Government and the Atomic Energy Authority have been having exploratory discussions with other countries to establish… the potential for collaborating with other countries as a means of securing the maximum benefits from this vital development programme.

Not everyone was convinced. Even Nuclear Engineering International had doubts. In February 1983, it declared:

The large amounts of money being spent worldwide by the nuclear industry on the development of fast breeder reactors is becoming increasingly difficult to justify… Will it ever be possible to recoup the vast sums that have been spent and the much greater sums that will need to be spent before the fast reactor can become a commercial option for electricity utilities? … Uranium will not be suddenly exhausted or become excessively expensive… There will be plenty of time to identify the trend… But perhaps of greater significance to fast reactor economics than the availability of uranium is the fact that with advances in techniques for the storage of irradiated fuel from light-water reactors utilities can avoid reprocessing. The uncertain and growing costs of reprocessing are then properly loaded on the fast reactor… In these circumstances fast reactors may never be economic… Evangelical fervour is not a substitute for sound technical argument.

In February 1984 the Comptroller and Auditor General published a terse report entitled "Development of Nuclear Power," expressing unease about the AEA’s financial performance; and the House of Commons Committee of Public Accounts looked into the matter. The committee chairman asked AEA chairman Sir Peter Hirsch "the estimated total cost of development" of the fast breeder. Sir Peter replied: "We have spent so far about £2400 million in 1982-83 prices. The forward development programme, assuming a certain profit for it, again in 1982-83 prices, is estimated to be £1300 million, the total being £3700 million." Asked "What have you got for all this money?" Hirsch continued:

The main thing we have got is that we have got the expertise in the UK to go forward to build a CDFR and then have a commercial programme.

For that money we shall be, we are, in the position to give the UK the option of having a fast reactor capability for producing electricity. We have done a cost benefit analysis of what the country would get out of it, making certain assumptions. Assuming that commercialization of the fast reactor starts in about 2015 and you have a programme of building fast reactors of 1.25 gigawatts electrical for about 30 years, you can estimate, admittedly on making certain assumptions of uranium price escalation, that you would expect benefits of several billions of pounds compared to the cost you would have to pay if you got the electricity from PWRs…

On 19 July 1984, the Select Committee on Energy pointed out the real import of Hirsch’s evidence:

Since 1955-56 some £2400m (in 1982-83 money values) has been voted for fast reactor R&D, and in the twenty years since 1962-63 real expenditure has remained remarkably steady at between £85m and £120m a year. In evidence to the Committee of Public Accounts on 2 April 1984, the Chairman of the UKAEA estimated that a further 25-30 years and additional R&D expenditure of £1300m (in 1982-83 prices) will be needed to reach the stage ‘where one hopes to obtain a commercial station’. To this figure must be added £2 billion construction costs for a commercial demonstration reactor and £300 million for reprocessing facilities, giving total estimated further expenditure of £3.3 billion and a cumulative figure of £5.7 billion. This implies that at present the fast reactor is roughly halfway through a perceived 60-year research, development and demonstration programme…