Nickel Dust (Hansard, 25 April 1996)

§ Mr. Page

[holding answer 23 April 1996]: The vast majority of UK electricity generation arising from fossil fuels is based on coal or natural gas combustion. Nickel features as a trace element in coal, with a typical concentration of 20 ppm covering a range from 0.5 to 50 ppm, and is also present in fuel oil.

Nickel compounds, along with other trace elements which are released to air during electricity production, are generally associated with particulates. These are captured by particulate removal devices which, in large coal-fired generating plants, exhibit a typical removal efficiency greater than 99 per cent. Emission levels of nickel compounds arising from the combustion of fuel in power stations are not identified separately. Controls on these substances are applied indirectly through the regulation of particulate releases and there is little routine monitoring of such trace elements or reliable estimates of their release in the UK.

Preliminary estimates provided by the power generators to the Environment Agency indicate that release rates are in the range 9x10^-3 to 4x10^-2 grams per second—g/s—for coal-fired stations and to 3 to 5 g/s for oil-fired stations. These levels are greater than the "significant release rate" of 8x10^-3 g/s proposed by Her Majesty's Inspectorate of Pollution in 1995. The "significant release rate" provides guidance to operators on the level of release above which the substance should be considered in any environmental assessment submitted as part of an application for authorisation under integrated pollution control. The "significant release rate" supersedes but performs the same function as the "Action Level" proposed by HMIP in a consultation guidance document on best practical 222W environmental option—BPEO—assessment procedures in April 1994. Under typical operating conditions, releases of this magnitude might be expected to result in ambient air concentrations which are less than 2 per cent. of the environmental assessment level for nickel as an annual average.

In view of the preliminary nature of these estimates, the Environment Agency has asked the major operators to provide a written response by 1 October 1996 to demonstrate how reliable annual estimates are to be provided for a number of trace substances, including nickel compounds.