On this page you will find detail of each Regulatory Observation and the associated Resolution Plan.
| Regulatory Observation title | RO ref. | RO res plan ref. | Closure letter |
|---|---|---|---|
| Avoidance of Fracture - Margins Based on the Size of Crack-Like Defects | RO-ABWR-0001 | RO-ABWR-0001 res plan | RO-ABWR-0001 closure letter |
| CRD Penetration Design | RO-ABWR-0002 | RO-ABWR-0002 res plan | RO-ABWR-0002 closure letter |
| RPV Design | RO-ABWR-0003 | RO-ABWR-0003 res plan | RO-ABWR-0003 closure letter |
| Material/Forging/Weld/Clad Specifications for RPV Pressure Boundary | RO-ABWR-0004 | RO-ABWR-0004 res plan | RO-ABWR-0004 closure letter |
| Hitachi-GE Nuclear Energy Human Factors Specialist Resource and Organisation | RO-ABWR-0005 | RO-ABWR-0005 res plan | RO-ABWR-0005 closure letter |
| Source Terms | RO-ABWR-0006 | RO-ABWR-0006 res plan | RO-ABWR-0006 closure letter |
| Spurious C&I Failures as Design Basis Initiating Events | RO-ABWR-0007 | RO-ABWR-0007 res plan | RO-ABWR-0007 closure letter |
| Common cause failure of electrical distribution systems | RO-ABWR-0008 | RO-ABWR-0008 res plan | RO-ABWR-0008 closure letter |
| Analysis of Loss of Offsite Power Events | RO-ABWR-0009 | RO-ABWR-0009 res plan | RO-ABWR-0009 closure letter |
| Design Basis Analysis of Essential Services and Support Systems | RO-ABWR-0010 | RO-ABWR-0010 res plan | RO-ABWR-0010 closure letter |
| Safety Case for Spent Fuel Pool and Fuel Route | RO-ABWR-0011 | RO-ABWR-0011 res plan | RO-ABWR-0011 closure letter |
| Presence of Single Doors on Class 1 Nuclear Safety Barriers | RO-ABWR-0012 | RO-ABWR-0012 res plan | RO-ABWR-0012 closure letter |
| Probabilistic Safety Analysis: Project Plan and Delivery | RO-ABWR-0013 | RO-ABWR-0013 res plan | RO-ABWR-0013 closure letter |
| Radiological Protection Safety Case: Project Plan and Delivery | RO-ABWR-0014 | RO-ABWR-0014 res plan | RO-ABWR-0014 closure letter |
| Mechanical engineering SSCs qualification and layout provision | RO-ABWR-0015 | RO-ABWR-0015 res plan | RO-ABWR-0015 closure letter |
| Mechanical Engineering Design Process Arrangement | RO-ABWR-0016 | RO-ABWR-0016 res plan | RO-ABWR-0016 closure letter |
| Nuclear Ventilation Codes and Standards | RO-ABWR-0017 | RO-ABWR-0017 res plan | RO-ABWR-0017 closure letter |
| Examination, Inspection Maintenance and Testing (EIM&T) Isolations and Configurations | RO-ABWR-0018 | RO-ABWR-0018 res plan | RO-ABWR-0018 closure letter |
| Reactor Chemistry Safety Case: Strategy, Plan and Delivery | RO-ABWR-0019 | RO-ABWR-0019 res plan | RO-ABWR-0019 closure letter |
| Internal Hazards Safety Case for the Main Steam Tunnel Room | RO-ABWR-0020 | RO-ABWR-0020 res plan | RO-ABWR-0020 closure letter |
| Limits and conditions of operation for Interim Dry Fuel Storage | RO-ABWR-0021 | RO-ABWR-0021 res plan | RO-ABWR-0021 closure letter |
| Primary Cooling System Chemistry ALARP | RO-ABWR-0022 | RO-ABWR-0022 res plan | RO-ABWR-0022 closure letter |
| Severe Accident Safety Case | RO-ABWR-0023 | RO-ABWR-0023 res plan | RO-ABWR-0023 closure letter |
| Human Reliability Analysis – Error of Commission / misdiagnosis | RO-ABWR-0024 | RO-ABWR-0024 res plan | RO-ABWR-0024 closure letter |
| Hitachi-GE Nuclear Energy Ltd. Safety Case Process and Capability | RO-ABWR-0025 | RO-ABWR-0025 res plan | RO-ABWR-0025 closure letter |
| Back-up Building C & I | RO-ABWR-0026 | RO-ABWR-0026 res plan | RO-ABWR-0026 closure letter |
| Hardwired Back Up System | RO-ABWR-0027 | RO-ABWR-0027 res plan | RO-ABWR-0027 closure letter |
| Safety System Logic & Control (SSLC) Class 1 HMI | RO-ABWR-0028 | RO-ABWR-0028 res plan | RO-ABWR-0028 closure letter |
| SSLC Production Excellence | RO-ABWR-0029 | RO-ABWR-0029 res plan | RO-ABWR-0029 closure letter |
| Embedded C&I subsystems and smart devices | RO-ABWR-0030 | RO-ABWR-0030 res plan | RO-ABWR-0030 closure letter |
| SSLC and Support System Architecture | RO-ABWR-0031 | RO-ABWR-0031 res plan | RO-ABWR-0031 closure letter |
| Safety System Logic & Control (SSLC) Design | RO-ABWR-0032 | RO-ABWR-0032 res plan | RO-ABWR-0032 closure letter |
| Human Reliability Analysis – Error of Commission / misdiagnosis | RO-ABWR-0033 | RO-ABWR-0033 res plan | RO-ABWR-0033 closure letter |
| Demonstrating the inclusion of a 'bottom drain line' in the UK ABWR design achieves inherent safety and reduces risks SFAIRP | RO-ABWR-0034 | RO-ABWR-0034 res plan | RO-ABWR-0034 closure letter |
| Robust justification for the materials selected for UK ABWR | RO-ABWR-0035 | RO-ABWR-0035 res plan | RO-ABWR-0035 closure letter |
| Demonstration that the approach taken to radioactive waste management reduces risks SFAIRP | RO-ABWR-0036 | RO-ABWR-0036 res plan | RO-ABWR-0036 closure letter |
| Safety Case for Faults not Directly Related to the Reactor | RO-ABWR-0037 | RO-ABWR-0037 res plan | RO-ABWR-0037 closure letter |
| Additional electrical power source | RO-ABWR-0038 | RO-ABWR-0038 res plan | RO-ABWR-0038 closure letter |
| UK learning from the Fukushima Dai-ichi events | RO-ABWR-0039 | RO-ABWR-0039 res plan | RO-ABWR-0039 closure letter |
| Probabilistic Safety Analysis: Identification of Applicable Internal Hazards | RO-ABWR-0040 | RO-ABWR-0040 res plan | RO-ABWR-0040 closure letter |
| Probabilistic Safety Analysis: Identification of Applicable External Hazards | RO-ABWR-0041 | RO-ABWR-0041 res plan | RO-ABWR-0041 closure letter |
| Probabilistic Safety Analysis (PSA) internal initiating events at power | RO-ABWR-0042 | RO-ABWR-0042 res plan | RO-ABWR-0042 closure letter |
| Demonstration of the adequacy of pH control in the Suppression Pool during accident conditions | RO-ABWR-0043 | RO-ABWR-0043 res plan | RO-ABWR-0043 closure letter |
| Demonstration UK ABWR has been designed to safely manage radiolysis gases generated under normal operations | RO-ABWR-0044 | RO-ABWR-0044 res plan | RO-ABWR-0044 closure letter |
| Operational Experience (OPEX) | RO-ABWR-0045 | RO-ABWR-0045 res plan | RO-ABWR-0045 closure letter |
| Containment Performance Analyses for Severe Accidents | RO-ABWR-0046 | RO-ABWR-0046 res plan | RO-ABWR-0046 closure letter |
| Mechanical Engineering – Wet Lifting Beams – Material of Construction | RO-ABWR-0047 | RO-ABWR-0047 res plan | RO-ABWR-0047 closure letter |
| Probabilistic Safety Analysis: Level 2 PSA methodology | RO-ABWR-0048 | RO-ABWR-0048 res plan | RO-ABWR-0048 closure letter |
| Mechanical Engineering – Dropped Load Counter Measures | RO-ABWR-0049 | RO-ABWR-0049 res plan | RO-ABWR-0049 closure letter |
| Mechanical Engineering – Crane control measures | RO-ABWR-0050 | RO-ABWR-0050 res plan | RO-ABWR-0050 closure letter |
| Mechanical Engineering – SSCs Qualification | RO-ABWR-0051 | RO-ABWR-0051 res plan | RO-ABWR-0051 closure letter |
| Mechanical Engineering - Design Process - SSCs' Detailed Design | RO-ABWR-0052 | RO-ABWR-0052 res plan | RO-ABWR-0052 closure letter |
| Probabilistic Safety Analysis (PSA) – level 1 and level 2 PSA for internal events during operation at power - System Analyses | RO-ABWR-0053 | RO-ABWR-0053 res plan | RO-ABWR-0053 closure letter |
| Chemical/Process Engineering Design Approach | RO-ABWR-0054 | RO-ABWR-0054 res plan | RO-ABWR-0054 closure letter |
| UK ABWR Generic Site Envelope - Seismic Hazard Definition | RO-ABWR-0055 | RO-ABWR-0055 res plan | RO-ABWR-0055 closure letter |
| Demonstration that adequate optioneering has been carried out for the removal of Spent Fuel from the Reactor Building | RO-ABWR-0056 | RO-ABWR-0056 res plan | RO-ABWR-0056 closure letter |
| Hitachi-GE's development of arrangements for the safety case to be met in practice | RO-ABWR-0057 | RO-ABWR-0057 res plan | RO-ABWR-0057 closure letter |
| Step 3 MSQA Improvement Actions | RO-ABWR-0058 | RO-ABWR-0058 res plan | RO-ABWR-0058 closure letter |
| Provision of Water Cooling for the RCCV Drywell Head of the UK ABWR | RO-ABWR-0059 | RO-ABWR-0059 res plan | RO-ABWR-0059 closure letter |
| Environmental impact of emissions to air from diesel generators | RO-ABWR-0060 | RO-ABWR-0060 res plan | RO-ABWR-0060 closure letter |
| Reactor Pressure Vessel Instrumentation Connections | RO-ABWR-0061 | RO-ABWR-0061 res plan | RO-ABWR-0061 closure letter |
| Testing and Maintenance of Safety Systems | RO-ABWR-0062 | RO-ABWR-0062 res plan | RO-ABWR-0062 closure letter |
| ABWR compliance with UK grid code | RO-ABWR-0063 | RO-ABWR-0063 res plan | RO-ABWR-0063 closure letter |
| Design approach to identification and provision of both permanent and temporary features necessary for the adequate control of radioactive contamination across the full lifetime of UKABWR | RO-ABWR-0064 | RO-ABWR-0064 res plan | RO-ABWR-0064 closure letter |
| Demonstration of adequate design and implementation of inherently safe techniques and structures to minimise radiation dose rates via through wall penetrations during all operating modes and for the lifetime of the facility, whilst being cognisant of design requirements relating to other discipline areas | RO-ABWR-0065 | RO-ABWR-0065 res plan | RO-ABWR-0065 closure letter |
| Demonstration of suitable and sufficient consideration of chemistry effects in fault analysis | RO-ABWR-0066 | RO-ABWR-0066 res plan | RO-ABWR-0066 closure letter |
| UK ABWR Generic Site Envelope - External Flooding and Beyond Design Basis events | RO-ABWR-0067 | RO-ABWR-0067 res plan | RO-ABWR-0067 closure letter |
| Civil Engineering Step 3 GDA Observation on Seismic Analysis Methodology | RO-ABWR-0068 | RO-ABWR-0068 res plan | RO-ABWR-0068 closure letter |
| HMI: Strategy, Application and Cognitive Issues | RO-ABWR-0069 | RO-ABWR-0069 res plan | RO-ABWR-0068 closure letter |
| Discharges to surface waters | RO-ABWR-0070 | RO-ABWR-0070 res plan | RO-ABWR-0070 closure letter |
| Turbine Gland Steam System: Discharges and Optimisation | RO-ABWR-0071 | RO-ABWR-0071 res plan | RO-ABWR-0071 closure letter |
| Suitable and sufficient consideration of chemistry control during UK ABWR commissioning | RO-ABWR-0072 | RO-ABWR-0072 res plan | RO-ABWR-0072 closure letter |
| Robust demonstration that the design of the UK ABWR off-gas system reduces risks SFAIRP | RO-ABWR-0073 | RO-ABWR-0073 res plan | RO-ABWR-0073 closure letter |
| 6.9kV Switchgear design for UK ABWR | RO-ABWR-0074 | RO-ABWR-0074 res plan | RO-ABWR-0074 closure letter |
| Robust demonstration that the design of the UK ABWR HVAC system has been adequately conceived and reduces risks SFAIRP | RO-ABWR-0075 | RO-ABWR-0075 res plan | RO-ABWR-0075 closure letter |
| PSA ALARP Demonstration and Optioneering | RO-ABWR-0076 | RO-ABWR-0076 res plan | RO-ABWR-0076 closure letter |
| Demonstration of adequate protection for Pellet-cladding Interaction in response to Control-rod Movement Faults | RO-ABWR-0077 | RO-ABWR-0077 res plan | RO-ABWR-0077 closure letter |
| Exceptions to Segregation | RO-ABWR-0078 | RO-ABWR-0078 res plan | RO-ABWR-0078 closure letter |
| Turbine Disintegration Safety Case | RO-ABWR-0079 | RO-ABWR-0079 res plan | RO-ABWR-0079 closure letter |
| Development of Spent Fuel Export Contingency Arrangements | RO-ABWR-0080 | RO-ABWR-0080 res plan | RO-ABWR-0080 closure letter |
| UK ABWR Sampling Capabilities | RO-ABWR-0081 | RO-ABWR-0081 res plan | RO-ABWR-0081 closure letter |
| Substantiation of the UK ABWR Class 1 Barriers against Internal Hazard Loads | RO-ABWR-0082 | RO-ABWR-0082 res plan | RO-ABWR-0082 closure letter |