Office for Nuclear Regulation

Sample statistics relating to cancer incidents near nuclear sites

Date released
11 June 2021
Request number
Release of information under
Freedom of Information Act 2000

Information requested

A few years ago when I worked in nuclear power we used to read stories in the Press where our power stations were blamed for greater-than-average incidences of cancers near our sites.

The averages that were quoted were national averages and could not be applied directly to small populations near our sites.

I understand in principle that the smaller the sample, the greater can be the variation from the national average without being ‘abnormal’. However I can’t remember the maths to prove this.

At the time, someone in the Nuclear Installations Inspectorate (NII) published an excellent booklet explaining in plain English how large sample statistics related to small sample results.

I’d very much like to see this booklet again, so please could you tell me if it is in your archives, and advise me how I could have a copy.

Information released

We have conducted a thorough search of our document management systems based on the information you have provided, and we can confirm that under Section 1 of the FOIA, we do not hold the information in scope of your request.

However, if you are able to provide more specific details in relation to the document, such as the title and the publication year, we would be happy to conduct a further search.

Exemptions applied


PIT (Public Interest Test) if applicable