1. April 20091Miguel Dapena TORE SUPRA Association Euratom-CEA On PP11 Safety Approach Requirement Analysis 1.Personal info 2.Introduction to the Procurement Package 11 3.Nuclear Safety & Regulatory Activities 4.Issues to consider on ITER nuclear safety 5.Proposed safety approach 6.Conclusion

2. April 20092Miguel Dapena TORE SUPRA Association Euratom-CEA 1 Personal info Miguel DAPENA FEBRER –25 years-old –Spanish –Engineering degree at ETSEIB-UPC, Barcelona Specialization on Nuclear Engineering –European Master of Science in Nuclear Engineering by ENEN –Working at FEEL-UPC EFDA Goal Oriented Training Program –3 years training program –Training on specific fusion subjects at a host Association –CEA, FZK, FZJ, HAS Consortium for Port Plug Engineering –Where am I ? Start date: January 2009 Training supervisor: Sophie SALASCA Subjects: Nuclear Safety, Neutronics, Nuclear Engineering for PPE GOTP - Port Plug Engineering

3. April 20093Miguel Dapena TORE SUPRA Association Euratom-CEA 2Introduction to the PP11 Equatorial Port Plug Port Interspace Port Cell What is a Port Plug Assembly Basic functions –Provide n,  shielding –Support BSM –Close VV ports providing 1st confinement barrier –Support and allocate diagnostics components & systems

4. April 20094Miguel Dapena TORE SUPRA Association Euratom-CEA License 2Introduction to the PP11 Design Port Plug Structure Design Vis/IR diagnostic (CEA) Altogether QA Which are the duties bound to PP11? Allocate & integrate all other diagnostics Manufacture & installation Testing Others… ITER = INB  Subject to the same strict norms as a regular fission plant

5. April 20095Miguel Dapena TORE SUPRA Association Euratom-CEA 3 Nuclear Safety & Regulatory Activities So, what does it mean that something has to be « licensed » ?  Licensing means that a part or the whole design is well demonstrated to be compliant with the rules and achieve the objectives imposed by a Regulatory Commission (ASN). But what kind of rules are those asked by the Regulatory Commission ?  Ultimate Safety Objective: “To protect people and the environment from harmful effects of ionizing radiation”  Technical Safety Objective: “To take all reasonably practicable measures to prevent accidents in nuclear installations and to mitigate their consequences, which could harm people or the environment”

6. April 20096Miguel Dapena TORE SUPRA Association Euratom-CEA 3 Nuclear Safety & Regulatory Activities How a design is assessed to be compliant with all those safety objectives and rules ? 1.Identify sources of radiation, toxicity, stored energy… that could threaten the safety objectives 2.Identify all systems provided in the design to guarantee safety 3.Identify all Postulated Initiating Events (PIE) that could lead to a sequence in which sources would threat safety objectives, even if its occurrence probability is very low 4.Guarantee that systems are capable to a.Prevent the occurrence accidents b.Mitigate the consequences of those accidents which safety systems are not capable to prevent 5.To be sure that there is an emergency plan in case all workers and near towns could be evacuated in case all previous measures fail High Level Waste from a Nuclear Power Plant As Low As Reasonably AchievableDefense in Depth ConfinementCooling Leak in confinement Sabotage in conf. Aircraft crash … Loss of Cooling Flow (pump break, pipe break, loss of electricity) Loss of heat exchange Out of expected range (DNB) Redundant, Independent and Diverse Safety Systems… Corium sinks, hydrogen recombiners/combustors,… Iodine pills, periodic emergency exercises, ready fleet of buses

7. April 20097Miguel Dapena TORE SUPRA Association Euratom-CEA 3 Nuclear Safety & Regulatory Activities But, ITER is an fusion experiment, and its amount of radioactivity will be several orders of magnitude below a regular fission plan !!  Regulatory Commission objectives & rules must be achieved no matter in what nuclear or radioactive installation  Historically, not to perform thorough and continuous safety assessments or neglecting (international) nuclear safety rules has led to commit terrible risks or even terrible accidents (1979) TMI USA (1999) TOKAIMURA Japan Everything has to be procedure Operator have to be thoroughly trained, even every several years Unexpected events

8. April 20098Miguel Dapena TORE SUPRA Association Euratom-CEA 3 Nuclear Safety & Regulatory Activities

9. April 20099Miguel Dapena TORE SUPRA Association Euratom-CEA There is no completed design of Port Plug Systems or Diagnostics yet  No final set of sources, PIEs, Safety System configuration, etc  Unknown design of other diagnostics  threating any Safety System? Regulatory Commission never licensed a fusion machine before  Huge amount of new (and unproven) technologies  reliability? Failure frequency? - Which could be the effect of a strong magnetic ? - How will be the embrittlement process on materials?  New field of reactor physics, kinematics & principle Life-cycle process unknown 4 Issues to consider So, what’s the problem? Why do we need a different safety approach for ITER?

10. April 200910Miguel Dapena TORE SUPRA Association Euratom-CEA 5 Proposed Safety Approach « So, do we need to stand sat until a final regulatory approach/design is established? » Objectives, Principles Guidelines Requirements Design Bear in mind that every stage should be as independent as possible on that one beneath Abstraction level DESCENDING DESIGN Method System engineering Method Functional design Systems design Components design Functional requirements System requirements Component requirements

11. April 200911Miguel Dapena TORE SUPRA Association Euratom-CEA « DESCENDING DESIGN » Method Objectives, Principles Guidelines Requirements Design 5 Proposed Safety Approach Objectives, Principles Requirements Guidelines Objectives: Requirements: Guidelines: Customer needs & expectations towards the project As simple & clear as possible Have to be enough & complete so that success can be achieved if those objectives are met Present necessary attributes, capabilities, qualities Feasible, Mandatory, Consistent, Observable They can be “purified” until having a requirement addressing to a unique need Compilation of know-how, good practices and recommendations to proceed with a design that meets the requirements Usually presented as a list of tasks and activities SHALLs SHOULDs Provide vacuum isolation between in-vessel and ex-vessel space Confinement barriers shall guarantee a leakrate lower than 10 -7 Pa.m 3 s -1 Vacuum Class materials and specific QA for those materials and parts should be used Descending Pressure cascade should be provided In-Operation leak test should be provided …

12. April 200912Miguel Dapena TORE SUPRA Association Euratom-CEA 4. Requirements/functional analyses 1.Gather needs from all stakeholders ITER / F4E IAEA / ASN etc Are needs towards the PP11 clear enough? …necessary and sufficient conditions to achieve success.. 3. Extract “imposed” requirements from stakeholders’ needs System engineering 5.Guides, Handbooks, manuals, know-how compilation 6.Design synthesis SAFETY Objectives, Principles Guidelines Requirements Design Objectives, Principles Requirements Guidelines 2.Define our objectives according to what has been said before 5 Proposed Safety Approach Work Plan proposal

13. April 200913Miguel Dapena TORE SUPRA Association Euratom-CEA 6 Conclusion ITER will be a Nuclear Installation needing to be licensed, as well as all its components There are still many uncertainties to perform safety assessments Safety assessments could use an scalable approach (Descending Design/System Engineering) to be applied since early stages of design Immediate steps: Stage at ITER Organization in the Safety Design and Integration Section  Gather ITER needs in relation with PP11 Stage at ENEA to be taught on MCNP calculations for Equatorial Port Plug  Neutronic assessments for PP11 Objective: Establishment of (preliminary) safety requirements for PP11

14. April 200914Miguel Dapena TORE SUPRA Association Euratom-CEA Thank you for your attention