B. R. Sehgal Professor Emeritus, Nuclear Power Safety (NPS) Royal Institute of Technology (KTH)

1. Presentation at the ERMSAR Meeting Karlsruhe, Germany, June 12-14,2007EXCELLENCE SPREADING ACTIVITIESinSARNET NETWORK B. R. Sehgal Professor Emeritus, Nuclear Power Safety (NPS) Royal Institute of Technology (KTH) AlbaNova University Center 106 91 Stockholm e-mail: bsehgal@safety.sci.kth.se

2. Objectives of the Program • Excellence Spreading Program is 3 years old. It is funded at a low-level but its objectives are important for the future impact of SARNET. The objectives are: - preserve, nurture and disseminate the knowledge gained since TMI-2 in LWR Severe Accident (SA) phenomenology, methodology and practice. - educate and train young researchers and students so that there is a cadre of trained persons who can continue to maintain and improve the high standards of safety that have been achieved over the last 20 years.

3. Program Elements • Consistent with the objectives outlined, the Excellence-spreading Program consists of the following program-elements: - development of a text book embodying what has been learnt so far about the SAs, - education of young researchers and students through the conduct of annual courses, providing both the presentation material and the lecture notes in text format, - training of young researchers and students through actual hands-on research work in the various experimental and the analysis-development projects that are being conducted in the SARNET Network. This involves the mobility of researchers and students from their own institutions to those of other partners for periods of a few weeks to several months.

4. The Text Book - 1 • The text book has been entitled, “LWR Severe Accident Safety”. An outline of the book was presented in the 2005 ERMSAR meeting. It follows the the SA scenario, preceded by a historical review of the LWR safety. The book length has been initially fixed at 400 pages; however there is some flexibility. • The first lecture course given in January 2006 also followed the progression of a SA, i.e. early in-vessel, late in-vessel, ex-vessel; branching into early and late containment failure, respectively with processes of steam explosion, hydrogen combustion, DCH, and MCCI, melt/debris coolability. These topics were complemented by source term, PSA, issue resolution, environmental impact, severe accident management and new designs. • Writing of the text lecture notes by the various lecturers has served as a practice run for the text book. Some additional topics will also be covered in the book, e.g., (1) structural aspects of containment failure, (2) description of models in ASTEC and MELCOR Codes, (3) SA progression for BWRs and CANDUS, (4) mechanistic modles for detailed description of key processes, (5) ATWS.

5. The Text Book - 2 • All the topics have been assigned to various experts. Writing is proceeding on most of the SA topics and some parts of the book have already been written. Leaders have been assigned for the major sections of the SA phenomenology. • We believe that the SA safety book will be a premier product of SARNET. The authors of the various subchapters are chosen to be those who are: - most knowledgable of literature on the subject - critical in evaluation and comprehensive in approach - cognizant of how their part fits in the whole picture - not advertising the research work they or their institution performed. • The schedule calls for the final draft of the book to be completed by January 2008 after extensive editing and review. The goal is to have the book published and available by August 2008, which is perhaps the completion date for SARNET-1.

6. Development of Courses - 1 • Two courses have been conducted so far. The first course on severe accident phenomenology (SAP) was focussed on students and young researchers while the second was focussed on engineers working in the industry (vendors, utilities, TSOs, regulatory bodies). • The program of the first course is shown in Table 1 showing lecture titles and lecturers, who were from the partner organisations. A tour of experimental facilities in Cadarache was provided. The course was held in January 2006. • The first course was a great success with 87 attendees and 15 lecturers. A photograph of attendees is shown . About 80% of the attendees were from EU countries and the rest from other parts of the World. There were 5 researchers from China, 4 from Pakistan and others from Russia, US, Canada and other countries. The attendees graded the course as 3.49/4. • The second course was also held in Cadarache in March 2007. The course lecture program is shown in Table 2. A significant addition in this course was the lectures on BWRs. There was also a lecture on the plant instrumentation. This course had 38 attendees, with a significant fraction coming from Canada.

7. SCHEDULE OF SAP COURSE IN 2006 Table 1

8. PARTICIPANTS

9. SCHEDULE OF SAP COURSE IN 2007 Table 2

10. Development of Courses - 2 • A third course is currently under preparation for delivery in March 2008. This course will be in collaboration with OECD/NEA, who want to describe results of some of the severe accident projects that they have organised over the years. • The course is tentatively entitled “Severe Accident analysis, Applications and Management Guidelines”. The course objective is to teach the students, researchers and nuclear safety engineers how to determine consequences (source-term) for SA scenarios for PWRs and BWRs. The consequence determination is part of the PSA-2 effort. The applications of ASTEC and MELCOR codes will bedescribed along with models in these codes. The second focus of the course is SAM and development of SAM guidelines to prevent a SA from occurring and to mitigate its consequences if it ever occurs. The attendees will learn how the management measures were decided on and how the analyses and the codes helped in designing the SAM measures. This can be demonstrated in particular for the prevention of the early failure of the containment. The measures for reduction of the ex-vessel consequences as practised in AP-1000, EPR and VVER-1000 will also be analysed through models and codes.

11. The Mobility Program • The Mobility Program consists of: - student summer internships - research delegation at the laboratory of a SARNET partner. • The procedure of application and approval has been established. The research to be conducted should be in the SARNET framework. The delegating and the host organisations agree on a work scope for the delegate, which has to be approved by the SARNET topical and excellence-spreading coordinators. • The mobility program in the third year had a better response than in earlier years. There were a total of 12 mobility actions in 2006-2007. This is shown in Table 3. We should note that there was a much greater number of female delegates coming from Eastern Europe and from Spain. • It is however, quite clear that there is not a large pool of young engineers in our field and we cannot hope to have a very large number of mobility actions. • As for the last year, the coordinator for excellence-spreading is trying to connect the delegates together with research projects offered by several institutions.

13. Dissemination of SARNET Research Results The SARNET Network needs greater visibility. This year, it is proposed to send brochures and newsletters to various industry organisations (vendors, utilities, TSOs, regulatory bodies) in Europe and other countries, describing the significant results in SA research that have been achieved in the first 3 years of the operations of SARNET Network.

14. Conclusions • The Excellence-spreading Program has set itself quite high goals, which will enhance the impact of the SARNET Network on the future of the nuclear enterprise in Europe. In particular, the text-book will be a legacy. It will help in preserving knowledge and in promoting the education of present and future students and researchers in reactor safety. The mobility program will promote European integration, since the students and researchers trained under this program will become the future links for collaboration between and among the different European universities and research laboratories.