Version 1.0, May 2015 BASIC PROFESSIONAL TRAINING COURSE Module XX Regulatory control Case Study This material was prepared by the IAEA and co-funded by the European Union.

Basic Professional Training Course; Module XX Regulatory control Regulatory Assessment of Operating Experience at an NPP Students should be given a task to outline a draft guide on how to evaluate the Feedback of Operating Experience (FOE) following an event at an NPP and conduct regulatory oversight. This guidance should reflect the main steps in the FOE process that should take place at a NPP and which should be verified by regulatory inspection. Students should be divided into working groups. Each group should be given 2 – 3 hours to complete the task. In a plenary, each group should present their results to be compared among them. The following slides give guidance to the lecturer on what to expect from each working group.

Basic Professional Training Course; Module XX Regulatory control The Event While cleaning the condensate polishers, the secondary feedwater pumps failed and the turbine tripped. The reactor shutdown but the auxiliary feedwater pumps failed to operate. The temperature and pressure of the primary coolant rose to the point where the pilot operated valve at the top of the pressuriser opened. The operators manually activated the auxiliary feedwater pumps, and the pressuriser valve closed.

Basic Professional Training Course; Module XX Regulatory control The Task Each student should start by ensuring that the guidance identifies the seven steps in the FOE process. For each one the guidance should identify the key elements of the activities that should be performed. For example, the first step is data collection. For this step, the guidance should cover: − When data collection should start; − What information should be collected; − How the information should be collected;

Basic Professional Training Course; Module XX Regulatory control Regulatory Inspection Review The regulatory inspection should verify if the FOE process at a NPP consists of the following steps: 1. Data Collection; 2. Data Review; 3. Event Analysis; 4. Root Cause Determination; 5. Validation of Root and Contributing Causes; 6. Corrective Action; 7. Event Reporting;

Basic Professional Training Course; Module XX Regulatory control Regulatory Inspection Review – cont. 1. Regulatory inspection should verify if the guidance on data collection following an event covers the following: − Data collection starts immediately following an event or identified problem; − Information collected consists of: − Conditions before, during and after the event, − Personnel involved and their actions (for possible future interviews), − Environmental factors, − Photos of the area, − Any physical evidence such as failed equipment; − Means of gathering information: − Interviews and walk-throughs with personnel involved, − Reviewing records (see the next slide for details), − Reviewing similar experience from other plants;

Basic Professional Training Course; Module XX Regulatory control Reviewing records − The regulatory inspection should examine the extent to which the records consist of the following: − Operating log books, − Maintenance, Inspection or Surveillance records, − Computer process data, − Procedures and instructions, − Work orders, − FSAR and Technical Specifications, − Equipment Manuals, − Drawings and flow charts, − Equipment history records, − Functional tests and specifications, − Meeting minutes and correspondence, − Plant reliability data, − Radiological survey data;

Basic Professional Training Course; Module XX Regulatory control Regulatory Inspection Review – cont. 2. Regulatory inspection should verify if Data Review guidance covers the following: − Determination of the safety significance of the event and if root cause analysis is needed; − If root cause analysis is not required data should be stored for trend analysis and as a minimum the following data should be entered into the plant data base: − Event causal factors, − Component location and systems affected, − Work group involved;

Basic Professional Training Course; Module XX Regulatory control Regulatory Inspection Review – cont. 3. Regulatory inspection should verify if Event Analysis guidance covers the following: − Reconstruction of what happened; − Many techniques can be used but the most common once are: − Event and Causal Factor Charting (ECFC) – to establish the sequence of events, − Fault Tree analysis – used when problem is known but causes are not clear, − Change Analysis – compare situation before and after the event, − Barrier Analysis – which barriers were broken, − Human Performance Evaluation – to determine human performance/error;

Basic Professional Training Course; Module XX Regulatory control Regulatory Inspection Review – cont. 4. Regulatory inspection should verify if Root cause determination guidance covers the following: − Identification of a root cause that is well defined. One possible/common definition is that “the root cause is a fundamental cause that, if corrected, will prevent recurrence of an event or adverse condition.” − Many techniques can be used to determine the root cause like among others: − ASSET, − MORT, − HPES, − MTO;

Basic Professional Training Course; Module XX Regulatory control Regulatory Inspection Review – cont. 5. Regulatory inspection should verify if Validation of Root and Contributing Causes guidance covers the following: − To validate the root and contributing causes in the sense that their removal will prevent recurrence, the following has to be determined: − If the causes were not present, the event would have not occurred; − If causes are corrected the event or similar condition will not recur;

Basic Professional Training Course; Module XX Regulatory control Regulatory Inspection Review – cont. 6. Regulatory inspection should verify if Corrective Actions guidance covers the following: − For each identified root cause a corrective action has to be determined − Corrective actions must: − Prevent recurrence of the same or similar events and conditions, − Be within the capability of the plant to implement, − Be such that they do not introduce additional risks; − Corrective actions must be further: − Prioritized based on their safety significance, − Entered into the plant schedule, − Implemented in a timely manner;

Basic Professional Training Course; Module XX Regulatory control Regulatory Inspection Review – cont. 7. Regulatory inspection should verify if the Event Reporting guidance covers the following: − The event report should be disseminated to: − Plant management, − All personnel involved, − To the RB if the reporting criteria are met, − To the International Reporting Schemes (IAEA, WANO) if the reporting criteria are met; The views expressed in this document do not necessarily reflect the views of the European Commission.