What did Lewis Wolpert mean when he stated that ‘reliable scientific knowledge is value-free and has no moral or ethical value’ (p. 1254)?  ?

He means that facts are facts. When science learned that the leaves fall off the trees when the weather gets cold because there's a thin layer of cells in the stem that die off in the cold, that was just fact-- no moral judgement. But the argument comes about when scientists ignore the possible consequences of their discoveries. At least one of the developers of the atomic bomb later regretted that he had contributed to that discovery after the bombs were used on Japan.