KAERI/TR-3051/2005 Basic Design of the Cold Neutron Research Facility in HANARO September 2005 Development of Cold Neutron Research Facility and Utilization Technology Korea Atomic Energy Research Institute 1 KAERI/TR-3051/2005 Basic Design of the Cold Neutron Research Facility in HANARO September 2005 Project: Development of Cold Neutron Research Facility and Utilization Technology Project Manager: H. R. Kim Project Team: K.H. Lee, Y.K. Kim, S.H. Ahn, Y.G. Cho, C.I. Chang, C.O. Choi, Y.J. Kim, J.W. Choi, J.J. Ha, K.Y. Han, S.H. Han, Y.S. Han, S.R. Hwang, H.S. Jeong, J.T. Jung, H.I. Kwon, B.S. Kim, M.S. Kim, S.H. Kim, H.R. Kim, B.C. Lee, Y.S. Lee, J.H. Lee, S.Y. Oh, J.H. Park, Y.C. Park, J.S. Ryu, Y.J. Yu, S.I. Wu 2 Contents 1. Introduction ·································································································1 1.1 Project Objective and Scope ·····························································································1 1.2 Design Requirement, Principle and Criteria ······································································2 1.2.1 User Requirements ·····································································································2 1.2.2 Safety Requirements ··································································································2 1.3 Project Schedule ·················································································································3 2. Basic Design of Moderator Cell ································································ 5 2.1 Calculation Method and Modeling ·····················································································6 2.2 Moderator Selection ··········································································································8 2.3 Nuclear Design of Moderator Cell ·····················································································9 2.3.1 Moderator Cell Shape Optimization ·········································································· 10 2.3.2 Effect of Void Fraction ······························································································· 15 2.3.3 Gain Factor and Maxwellian Distribution ·································································· 16 2.4 Nuclear Heating Rate and Neutron Flux ········································································· 17 2.4.1 Design and Fabrication of Measurement Device ······················································ 18 2.4.2 Heating Rate and Neutron Flux Measurements ······················································· 21 2.4.3 Heat Load Analysis ··································································································· 24 References ···························································································································· 27 3. Basic Design of In-pool Assembly ··························································29 3.1 Materials Selection ··········································································································29 3.1.1 General Materials Consideration ················································································29 3.1.2 Materials Selection for the Moderator Cell ································································29 3.1.3 Materials Selection for the Vacuum Chamber ··························································31 3.1.4 Conclusions ···············································································································33 3.2 In-pool Assembly Design and Layout ··············································································33 3.2.1 Design Requirements ·······························································································33 3.2.2 In-pool Assembly Design and Layout ········································································34 3.3 Structural Analysis of In-pool Assembly ··········································································39 3.3.1 Configuration of In-pool Pressure Assembly ·····························································39 3.3.2 Structural analysis of In-pool Pressure Vessel ··························································41 3.3.2.1 ASME Code Acceptance Criteria ·····································································41 3.3.2.2 Combined Load ·······························································································41 3 3.3.2.3 Stress and Buckling Analysis of In-pool Pressure Vessel ·······························42 3.3.2.4 Fatigue and Fracture Evaluation ·····································································44 3.3.3. Conclusion ···············································································································44 3.4 Measurement of CN Hole Dimension ··············································································44 3.4.1 Measurement Method ·······························································································44 3.4.2 Measurement Results and Verification ·····································································46 3.5 Water Film and Installation Concept ···············································································48 3.5.1 Thickness of Water Film ····························································································48 3.5.2 Installation Concept ···································································································49 3.6 Shielding of In-pool Assembly ·························································································50 3.7 Inspection of Fabricated Moderator Cell ·········································································51 3.7.1 Microstructure Examination ······················································································51 3.7.2 Tensile Test ···············································································································53 References ····························································································································55 4. Thermo-siphon Mock-up Test ·································································56 4.1 Purposes of the Mock-up Test ························································································56 4.2 Small-scale Mock-up Test ·······························································································57 4.3 Full-scale Mock-up Test ···································································································61 4.3.1 Thermal Hydraulic Analysis ······················································································61 4.3.2 Full-scale Mock-up Test ····························································································66 4.4 Conclusion ·······················································································································70 References ····························································································································71 5. Systems and Structures for Cold Neutron Source ································73 5.1 Classification of Structures, Systems and Components ·················································73 5.1.1 Safety Class ··············································································································74 5.1.1.1 Safety Class 1 (SC-1) ······················································································74 5.1.1.2 Safety Class 2 (SC-2) ······················································································75 5.1.1.3 Safety Class 3 (SC-3) ······················································································75 5.1.1.4 Non-nuclear Safety (NNS) ···············································································76 5.1.2 Seismic Category ······································································································76 5.1.2.1 Seismic Category l ···························································································76 5.1.2.2 Seismic Category II ·························································································77 5.1.2.3 Non-seismic Category (commercial) ·······························································77 5.1.3 Quality Class ·············································································································77 4 5.1.3.1 Quality Class Q ································································································77 5.1.3.2 Quality Class T ································································································78 5.1.3.3 Quality Class S ································································································78 5.1.4 Electrical Classification ·····························································································78 5.1.4.1 Class 1E ··········································································································78 5.1.4.2 Non-class 1E ···································································································79 5.1.5 Relationship between Safety Class and Code Class ················································79 5.1.6 Classifications and its Bases ····················································································80