Tony Benn wrote his obituary in 1993:
"Kelvin Tallent Spencer, scientist: born 7 July 1898; MC 1918; CBE 1950; Chief Scientist, Ministry of Power 1954-59; Kt 1959; married 1927 Phoebe Wills (died 1989; one son); died 28 February 1993. He served, and was decorated for gallantry, in the First World War, played a large role in the development of the post-war aircraft industry, and in 1952 moved to become the Chief Scientist at the Ministry of Fuel and Power where he supervised the early work on the formulation of Britain's new civil nuclear programme...
"Later, as a result of his own experience and concern at certain safety aspects of this programme (in particular the accidental fire at Windscale in 1957), Spencer in his retirement in the Sixties, concluded that he had been wrong and that the whole nuclear power policy should be scrapped, a view which I later came to share. When, as Energy Secretary, I decided to convene a representative weekend conference at Sunningdale in 1977 to discuss policy I asked civil servants to invite Kelvin Spencer, hoping that he would be a counter-balance to the conventional view.
"I was strongly advised against inviting him, by senior civil servants, on the grounds that he was senile. A scandalous charge to make against a man of immense experience whose only problem for Whitehall was that he had taken a line that was unacceptable to the nuclear lobby, which was, at the time, deeply entrenched at the heart of government.
"Kelvin Spencer came to the conference and it was there that I met him - a wise, experienced and kindly man whose interests extended well beyond technology of energy to the widest social and political implications of any decision that might be made. He was clear, modest and incisive and made a formidable contributions to our discussions that weekend.
"Later I met him again on various occasions and he retained that combination of sharp intellect and humane sensitivity that is so rarely to be found in one person. He was always shrewd and generous in the presentation of his arguments but there is no doubt that he was a victim of the same sort of marginalisation that is used to exclude anyone whose views do not fit into the establishment consensus of the day. In short he was treated as a dissident, whose isolation was intended as a punishment for his defection from what had become a central item of almost religious belief among top people - that nuclear power was the right and proper course to be followed.
"As a result of his principled stand he won the respect and affection of the younger generation who suspected that the 'Atoms for Peace' programme was really a thin cover for the development of nuclear weapons, and was unsafe and far more expensive than coal - as it is." 
Resources and articles
- independent Obituary: Sir Kelvin Spencer , organizational web page, accessed September 2, 2012.