Working Party on Criticality (WPC)

Latest News

WPC Continuing Professional Development Webinar:

Next webinar: 1-2pm 5 July 2022 'An Introduction to Cyclone - Monte Carlo Data Processing and Validation', Stewart Hay, Cerberus Nuclear

The webinars are open to anyone with an interest in criticality safety. Contact, or for further details or for an invitation to the webinar series.

UK Award Winners at American Nuclear Society (ANS) Nuclear Criticality Safety Division (NCSD) Topical Meeting

At the ANS NCSD topical meeting in June both Amy van der Vyver (pictured left) and Katrina Christaki (right) won awards for their presentations.

Amy, a trainee criticality safety assessor at Sellafield Ltd, presented 'Establishing the UK Working Party on Criticality Webinar Series to Support Continuing Professional Development'. The paper was co-authored by Emma Williams (UK National Nuclear Laboratory). Amy and Emma helped instigate the WPC webinar series in March 2021 and have jointly coordinated it since.

Katrina, from Cerberus Nuclear, presented 'CARTA -- Criticality Safety Virtual Reality Training Aid, Recent Developments'. Katrina and Stewart Hay also enabled numerous meeting attendees to try out the CARTA virtual reality headset to see its potential as a criticality safety training tool .

Congratulations to both Amy and Katrina.

Criticality Awareness and Training Resources: Links have been added to a series of videos and other material providing criticality awareness and also more detailed training resources.

Links to WPC Good Practice Guides: Links have been added below to enable general access to published WPC Good Practice Guides.

December 2021 - added:

Forthcoming Events

1pm 5 July 2022 WPC Webinar - 'An Introduction to Cyclone - Monte Carlo Processing and Validation', Stewart Hay (Cerberus Nuclear)

13-15 Sept 2022 ANSWERS Seminar

14 Sept 2022 WPC Meeting

1-6 October 2023 International Conference on Nuclear Criticality Safety (ICNC), Sendai, Japan

Who We Are

The Working Party on Criticality (WPC) is a non-executive UK national committee focussing on criticality safety issues up to, but not including, experimental and in-core power reactor operations. WPC is a formal sub-group of the Safety Directors Forum. The issues considered are relevant to fabrication, transportation, storage and other operations relating to nuclear materials (e.g. new build, enrichment, reprocessing, decommissioning and long-term waste management).

  • WPC Scope and Objectives

  • WPC Members

    • WPC members comprise Nuclear Site Licensees and other organisations with an interest in criticality safety.

  • WPC Sub-groups

    • WPC has a number of sub-groups to cover specific topic areas. Participation in sub-groups is not restricted to WPC members. Contact for details. Current groups include:

      • Criticality Assessment of Fissile Wastes

      • Nuclear Codes and Data

      • Fault Analysis techniques

      • Learning from Experience

      • Organisational Criticality Health

      • Criticality Emergency Planning

      • Transport Criticality assessment

      • ISO criticality standards development

      • Criticality Handbooks

  • Continuing Professional Development

    • WPC run an annual workshop to provide opportunities for less experienced practitioners to gain experience on a wide range of technical issues. The workshops also provide an opportunity to improve communication between less experienced members of the criticality community. Participation in workshops is open to all with an interest in criticality safety, not just WPC members.

    • Since March 2021 WPC have hosting monthly webinars. These are run as hour long sessions, which enables a main speaker to cover a specific topic of interest and allows time for questions and further discussion. To date, presenters from a variety of UK licensed sites and consultancies and from the UK regulating body have taken part in the series. Typically, there are 50-100 attendees for each webinar. Topics covered include Learning From Experience (LFE) for criticality inspections, criticality safety of deep geological disposal and application of criticality ‘hand methods’.

  • WPC Papers Since the 1970s over 290 WPC papers have produced. These cover a range of topics from:

What is Criticality Safety?

For a brief introduction to what criticality safety is all about see the following: What is Criticality Safety?