1. Human Intrusion and Future Human Actions in relation to Disposal of Radioactive Waste TM 42929 September 24, 2012 Presented by: L. Bailey on behalf of NEA Prepared by: G. Kwong 1 IAEA TM 42929, Vienna

2. Background (1) The NEA began their evaluation of human intrusion in projects carried out in the late 80’s and in the 90’s.  In 1989, OECD NEA organized a workshop on Risks Associated with Future Human Intrusion at Radioactive Waste Disposal Sites;  Workshop resulted with the formation of a working group to assess future human actions at radioactive waste disposal sites in 1990.  The Working Group put together a catalogue of future human active assessments in 1993. 2 IAEA TM 42929, Vienna

3. Background (2) In 1995, published Report “Future human actions at disposal sites” i. Describes main issues concerning the treatment of future human actions; ii. Discusses means to reduce the risks associated with future human actions; and iii. Presents a general framework for the quantitative consideration of future human actions in radioactive waste disposal programmes. iv. Established the principle that protection should not focus on “advertent” intruder 3 IAEA TM 42929, Vienna

4. Background (3) Areas that were not addressed in the 1995 report: i. No considerations on the regulatory policy aspects of future human actions; ii. No explicit coverage on near-surface disposal of LLW; iii. No considerations on the long-term consequences of human actions taken during the pre-closure period. Recommendations:  Further discussion of regulatory policies for judging the risks associated;  Develop a set of methodological principles for the construction of human action scenarios;  Develop an internationally reviewed database of FEP for safety assessments;  Develop an international archive of radioactive waste repositories;  Develop durable marker systems. 4IAEA TM 42929, Vienna

5. Background (4) Based on recommendations identified, human intrusion has been continually evaluated in various NEA initiatives. E.g.: i. Considering Timescales in the Post-closure Safety of Geological Disposal of Radioactive Waste, 2009;  Human evolutionary changes over long time frames were discussed. Complementary lines of arguments were also evaluated. ii. International experiences in safety cases: results of the INTESC project, 2009;  Human intrusion was considered in monitoring, performance confirmation and long- term science programmes. iii. Methods for Safety Assessment of Geological Disposal Facilities for Radioactive Waste (MeSA), 2011  In developing scenarios for the safety case and in compilation of safety relevant FEPs, various possible future human actions which may impair the performance of the disposal system were analyzed. 5IAEA TM 42929, Vienna

6. Key Conclusions from these projects  Human intrusion scenarios, developed for enhancing robustness of the safety case, shall consider inputs from all national stakeholders;  A range of approaches have been used in safety assessment of the different national programmes for addressing human intrusion;  The degree of regulatory requirements of the approaches used (to address human intrusion in the safety assessment) also varies considerably among national programmes;  Importantly, the NEA International FEP database addresses also future human actions and behaviours. 6IAEA TM 42929, Vienna

7. More specific and current work activities (1) From the drawn conclusions, human intrusion was further explored in a NEA Regulators’ Forum (RF) workshop entitled “Towards Transparent, Proportionate and Deliverable Regulation for Geological Disposal”, held in Tokyo, in 2009. Specifically, the WS discussed these issues: i. Approaches used to deal with human actions; ii. Analysis of human intrusion scenarios; iii. Means to reduce probabilities of human activities in the vicinity of the disposal site (e.g. markers) 7IAEA TM 42929, Vienna

8. More specific and current work activities (2) Key findings of the 2009 Workshop:  Reduction of the likelihood and the consequences of intrusion are important goals;  Measures are required to assure information maintenance over a long time period;  The results of human intrusion scenarios should be used in safety cases to demonstrate robustness, rather than regulation compliance. More work is also needed on criteria and indicators;  More regulatory guidance is needed in the field of human intrusion aspects. 8IAEA TM 42929, Vienna

9. More specific and current work activities (3) NEA’s involvement in developing new ICRP Publication  Publication is the latest guidance on geological disposal of long- lived solid radioactive waste; In particular, the ICRP adopted the NEA’s concept of oversight, a concept developed in the NEA R&R project  Inadvertent human intrusion is addressed in Section 4.3.4 [ICRP ref 4838-8963-9177, July 21, 2011 version, http://www.icrp.org/docs/Radiological_protection_in_geological_dis posal.pdf]. Specifically, human intrusion scenarios as well as how direct and indirect passive oversights can be employed to reduce the possibility of inadvertent human intrusion are discussed. Human action scenarios are for discussing robustness not regulatory compliance. http://www.icrp.org/docs/Radiological_protection_in_geological_dis posal.pdf 9IAEA TM 42929, Vienna

10. More specific and current work activities (4) NEA’s Concept of Oversight (1)  In this concept, there is societal willingness and actions to keep a watchful eye on the disposed waste after closure. Regulators and others have to decide what they plan to do.  Potential human intrusion scenarios are ideally pushed forward into the no oversight period (often assumed to go beyond 500 years) (1) Glossary of Key Terms of the RK&M Project, [http://www.oecd- nea.org/rwm/docs/2011/rwm2011-14.pdf] 10IAEA TM 42929, Vienna

11. More specific and current work activities (5) Records, Knowledge, and Memory (RK&M) Project  An international project created by the NEA RWMC to address the preservation of RK&M across generations.  Measures for records and memory keeping shall reduce the risks of human intrusion, as concluded in a recent RK&M workshop (Sept 2012) project.  A recent survey within the NEA IGSC (July 2012) confirms that human intrusion is a concern for the post-closure safety case. Many national programmes assume that RK&M will be preserved for a few hundred years, during which, human intrusion will not occur.  In the social and cultural context of the RK&M Project, various aspects of human behaviour leading to loss or misuse of records are identified and evaluated. 11IAEA TM 42929, Vienna

12. More specific and current work activities (6) Observations in a recent NEA organized peer review :  In the 2011 peer review of SKB’s post-closure safety case, the review concluded that “SKB does not draw any strong conclusions from the assessment of future human actions…”  The review suggested various areas of memory keeping (e.g. creating reservoirs of knowledge, identify site using permanent monuments or durable markers ; record archives at regional and national agencies, centres of interest, etc), to be developed as examples of best available technology (BAT), which will reduce the risk of human intrusion.  Review report: http://www.oecd-nea.org/rwm/docs/2012/rwm- peer2012-2.pdf 12IAEA TM 42929, Vienna

13. More specific and current work activities (7) Current work on Monitoring Geological Disposal Facilities  Monitoring is a form of oversight activity  An overview document summarizing the key issues of monitoring deep geological disposal facilities is under development.  In this report, monitoring in the vicinity of the disposal system is discussed as a means to reduce risk of human intrusion and to its verify effects, should it ever happen.  Report is anticipated to be issued in Q2, 2013. 13IAEA TM 42929, Vienna

14. NEA Reports on Human Intrusion 14 1. Risks associated with human intrusion at radioactive waste disposal sites, NEA workshop, June 1989 2. Catalogue of future human action assessments in radioactive waste repository safety assessment undertaken by OECD member countries 1993. 3. Future human actions at disposal sites, 1995 [http://www.oecd- nea.org/rwm/reports/1995/nea6431-human-actions.pdf] 4.Considering timescales in the post-closure safety of geological disposal of radioactive waste, 2009. 5.International experiences in safety cases: results of the INTESC project, 2009. [http://www.oecd-nea.org/rwm/reports/2009/nea6251-INTESC-eng.pdf] 6.Towards Transparent, Proportionate and Deliverable Regulation for Geological Disposal, Workshop Proceedings, Tokyo, Japan, 2009 [http://www.oecd- nea.org/rwm/docs/2009/rwm-rf2009-1.pdf] 7.Methods for Safety Assessment of Geological Disposal Facilities for Radioactive Waste (MeSA), 2011 [http://www.oecd-nea.org/rwm/reports/2012/nea6923- MESA-initiative.pdf] IAEA TM 42929, Vienna