Assuring the human resources for severe accident management and environmental remediation Ian McKinley & Susie Hardie
Introduction By their very nature, severe accidents tend to be unique in terms of their development and impact, while resultant environmental remediation is dependent on site-specific conditions and requirements. This complicates planning and, in particular, the assurance of required human resources (HR). As was seen for the Fukushima Daiichi ( 1F ) case, the availability of teams with the required expertise is a key constraint on effective management of radioactive contamination. What can we learn from 1F (and other accidents / remediation responses) to ensure better preparation for future incidents?
1F lessons learned The combination of an enormous earthquake, a huge tsunami and melt-down of three reactors went beyond the worst case scenario of Japan s well-established natural hazard response system. In retrospect, common-mode failure of nuclear defence in depth was predictable if hazards had been evaluated in a more holistic manner, utilising the multi-disciplinary knowledge base available. Modern knowledge management tools can help identify such Black Swans, develop credible perturbation scenarios and identify required counter-measures / responses. A critical aspect of response management is assuring availability of required HR
The challenges For accidents involving extensive radioactive contamination, effective response requires teams with expertise to: quantify the distribution of key radionuclides (RNs) in the environment assess likely future RN redistribution determine radiological hazards / develop response plans communicate with all stakeholders Coordination is a particular challenge, often complicated by conflicting requirements in the case of regional disasters, political interference and disinformation by nuclear opponent groups. Even if major accident probability is very low, the consequences are so large that response coordinators should be trained for a fully representative range of scenarios.
Environmental monitoring A sufficiently accurate & complete map of contamination must be provided as a pre-requisite to guide responses, possibly under difficult conditions and extreme time pressure: Based on pre-existing monitoring network, if available Aerial measurements essential for larger areas (conventional / drone) Must be complemented by measurements on the ground (mobile / point) and comprehensive sampling for lab analysis Integration / intercalibration / database management key problem (especially as the number of involved groups / organisations increases) Sampling in complex environments requires practical expertise...
Modelling Natural environments are dynamic and it is critical to assess likely future redistribution: Requires efficient input and processing of monitoring data Multidisciplinary: radiochemical components must be integrated with biology / microbiology, climate / weather, human actions,... Can be based on existing models, but essential to tailor to individual boundary conditions Assumptions must be clearly understood and uncertainties must be explicitly stated Wherever possible, models should be tested (verification / validation), ideally based on analogue test cases 137 Cs (Bq kg -1 ) 0 0 500 1000 1500 2000 2500 Depth (cm) 5 10 Chernobyl 1986 Bomb fallout peak 1963 15
Hazard assessment RN distributions may be the main output from monitoring / modelling, but realistic assessment of associated hazards must be determined as a basis to guide responses Is evacuation necessary? Do benefits balance the known detriments? What controls on use of local water / produce / resources are required? What remediation is required? Are there specific advantages for rapid / delayed action?
Response planning May be usefully broken down into: Immediate actions taken during the development of the accident Short-term plans mobilisation of resources required to minimise impacts over periods of days, weeks, months... Long-term plans response required to restore environment to acceptable level, potentially extending over years or decades Cost / benefit analysis is critically important to optimise actions: Continually assess effectiveness and modify responses based on experience Ensure that use of resources for radiological response is appropriate considering other demands following a major accident Fully consider all waste management issues!
Communication Technical audiences: Output must be made openly available, clearly identifying associated uncertainties, as rapidly as possible Ensure consistency between specialists and generalists Decision makers & general public: Results should be put in context by experienced generalists Actions against disinformation extremely important!
Coordination Coordination requires a team capable of rapidly grasping the significance of an accident and effectively managing responses Depends on an unusually wide knowledge base, covering past severe accidents, experience with different kinds of remediation, waste management, socio-political aspects,... Background can be gained by wide experience coupled by training for a representative range of scenarios Can be facilitated by advanced KM tools, particularly to foster lateral thinking during both scenario definition and formulation of responses
HR management The required expert teams for support work vary considerably for different scenarios it is impossible to maintain such resources only for the case of very unlikely events. Most of the radiochemists (or other scientists) involved re-assigned from other work: Rapid identification of staff available and their expertise will facilitate the extent, speed and quality of the work carried out Training of radiochemists should be widened to allow more flexibility in their work role, e.g.: general principles of environmental monitoring, site cleanup and waste management could well be applied to environmental chemists in general, as it may well be that the next major environmental accident involves chemotoxins rather than radionuclides. Key 1F lessons (off-site) documented by JAEA
Conclusions and future perspective Future radiological accidents and demands to clean up legacy contamination are inevitable Planning to assure required HR is prudent BUT should not be based on preconceptions from past accidents may be initiated by volcanoes / climate change / human actions rather than tsunamis; may involve sources other than power reactors (e.g. military / back-end facilities) As with 1F, even accidents with a nuclear component may be dominated by nonnuclear impacts This is increasingly likely as a result of global population growth, with major conurbations and sensitive industrial infrastructure expanding into areas with significant natural hazard risks and competition for key resources (e.g. water) increasing the risks of regional conflicts.
Assuring effective use of HR Best use of limited human resources requires making appropriate support and training tools available; these can be relatively easily and cheaply developed especially if part of an international collaboration. Additionally, such limitations can be reduced by mobilising resources on a regional / international rather than national level which is especially important for countries with smaller nuclear programmes. NB bodies like IAEA too bureaucratic to be effective: supply only panels of gurus who may be more of a disruption than a help This needs to be facilitated by developing internal legislation and agreements / procedures for international cooperation in advance after an accident happens it is too late!
Acknowledgements Our perspective on the 1F accident developed from a number of collaborative projects involving many Japanese colleagues, who are too numerous to name but are all gratefully acknowledged ian@mckinleyconsulting.ch 들어주셔서감사합니다 shardie@intera.com