Safety programmes are primarily directed at avoiding nuclear criticality accidents. However, the possibility of such accidents exists and the consequences can be life-threatening. For facilities that are judged to have a credible criticality accident risk, this necessitates advance planning, practice in planned emergency responses, and verification of readiness. Two distinct phases are identified:

  • The emergency preparedness phase, that needs to be enforced continuously
  • The emergency response phase that needs only to be activated when it is indicated that a criticality accident could be developing, could be occurring or could have occurred.

As underlined by Neal Harris, ISO11320:2011 Project Leader, and Calvin Hopper, Working Group Convener, "At nuclear facilities, safety and anticipation are priorities. The new ISO standard, ISO11320:2011, provides criteria for emergency preparedness and response to minimize consequences due to a nuclear criticality accident."

ISO11320:2011 applies to a site with one or more facilities which might contain significant quantities and concentrations of fissile material. The extent to which this standard needs to be applied depends on the overall criticality risk presented by the facilities at the site.

ISO11320:2011 was developed by ISO/TC85, Nuclear energy, nuclear technologies, and radiological protection, subcommittee SC5, Nuclear fuel cycle, working group WG 8, Standardization of calculations, procedures and practices related to criticality safety. It is available from ISO national member institutes (see the complete list with contact details. It may also be obtained directly from the ISO Central Secretariat, price 66 Swiss francs, through the ISO Store or by contacting the Marketing, Communication & Information department.