Dynamics of agency governance: Evidence from the Nuclear safety sector

Public organizations are compound bodies characterized by competing endogenous dynamics of governance. This study makes two main contributions. First, it contributes to an organizational approach to studies of public policy and administration by conceptualizing compound agency governance. Second, by determining how variation in agency governance reflects endogenous organizational factors. Based on a study of the Norwegian Radiation and Nuclear Safety Authority (DSA), two observations are highlighted: Firstly, DSA staff are torn between two competing behavioural logics: A governmental and a transnational logic. Moreover, portfolios of core state powers are more closely monitored by parent ministries than portfolios that relate to non-core state powers. Secondly, the study suggests that organizational factors are vital determents in balancing behavioral logics in agency governance.

VVUQ of a thermal-hydraulic multi-scale tool on unprotected loss of flow accident in SFR reactor

Within the framework of the French 4th-generation Sodium-cooled Fast Reactor safety assessment, methodology on VVUQ (Verification, Validation, Uncertainty Quantification) is conducted to demonstrate that the CEA's thermal-hydraulic Scientific Computation Tools (SCTs) are effective and operational for design and safety studies purposes on this type of reactor. This VVUQ-based qualification is a regulatory requirement from the French Nuclear Safety Authority (NSA). In this paper, the current practice of VVUQ approach application for a SFR accidental transient is described with regard to the NSA requirements. It constitutes the first practical, progressively improvable approach. As the SCT is qualified for a given version on a given scenario, the transient related to a total unprotected station blackout has been selected. As it is a very complex multi-scale transient, the SCT MATHYS (which is a coupling of the CATHARE2 tool at system scale, TrioMC tool at component scale and TrioCFD tool at local scale) is used. This paper presents the preliminary VVUQ application to the qualification of this tool on this selected transient. In addition, this work underlines some feedback on design and R&D aspects that should be addressed in the future to improve the SCT.

Why declare events? What to draw from experience feedback?

Issue In France, the reporting of significant radiation events for nuclear activities is a mandatory system since July 2007 following the accident of oncology in Epinal. Later, the directive 2013/59/EURATOM states that Members of the European Union shall ensure that a system of experience feedback is in place for the dissemination of lessons. In France, it was implemented in 2011 through the publication of a newsletter, “Patient safety: Paving the way for progress” on radiotherapy, it is now extended to medical imaging. Until 2015 the number of reported events was stable but steadily decreasing in radiotherapy since 2016. Lack of time to report, lack of awareness and training of doctors, fear of consequences in terms of communication on the establishment that reports and in terms of control by the ASN following the report may explain the decrease. Educational actions need to be lead to reaffirm the objectives of reporting and reinforce the interest of experience feedback. The French Nuclear Safety Authority decide to focus a newsletter on international reporting systems and Experience feedback based on the reflections of a French institutional working group. Results According to professionals it is sometimes difficult to report an event with impact on patients, easier to work on near miss and even easier to work on events happening elsewhere. Reporting an incident is thus a collective action. The experience feedback process allows learning in order to improve practices in the future and address three aspects: Benchmarking, Prospective risk analysis for the techniques/devices which have never been used in a centre, Analysis of concrete cases during feedback experience meetings. The limit of the current systems is the difficulty in finding precise information due to shortcomings in its structure. A simplified system is needed. Lessons Reporting events on websites highlight new events and enable the solutions implemented elsewhere to be disseminated in our own networks. Key messages Reporting adverse events or near miss has a collective impact. Experience feedback allows dissemination of lessons and prevents incidents.

Impact of Deviations Handling on Outages

Based on the information provided by the operators, IRSN experts select and analyze different deviations presenting a possible generic nature which could affect the safety of power plants. Some of these deviations result in non-compliance (NC) with the safety requirements. To maintain an acceptable level of safety, an operator has to implement corrective measures for any situation of non-compliance with safety requirements. IRSN, the Technical Support Organization of the French Nuclear Authority, analyzes the different deviations to assess the impacts on the concerned NPPs safety. Based on the impact on safety, measures should be applied immediately or during the next outages, on a reactor or on several of them. The permanent corrective measures schedule is defined taking into account the “NC” safety impact. However, for some of the “NCs”, it can be difficult to define and implement swift permanent corrective measures, especially when the lack of compliance affects several similar units and requires a design change. This paper explains the French approach of deviations treatment and specifically the relationship between the Nuclear Safety Authority, the Technical Support Organization, IRSN and the Licensee, EDF during an outage.

Statement of the French Safety Authority Concerning the Behaviour of 900 MWe PWR RPV Between 30 and 40 Years in Operation

The French 900 MWe reactor pressure vessel (RPV) integrity demonstration was reviewed in 2010 by the French Nuclear Safety Authority (ASN), together with its technical support organisation, the French Institute for Radiation Protection and Nuclear Safety (IRSN). The purpose was to decide whether these 3-loop PWR RPV’s are able to remain in service for ten years after their third decennial outage (VD3). ASN and IRSN examined the demonstration developed by Electricite´ De France (EDF) in order to ensure the compliance of in-service RPV behaviour with regulatory requirements and to check the validity of the calculations and hypotheses that were used for that purpose. The analysis aimed notably at ensuring that the results of every calculation step were conservative and that regulatory safety margins were applied. The calculations made by EDF showed that regulatory criteria were met until the provisional deadline of their fourth decennial outage (VD4). Thus ASN considered that the serviceability of all 900 MWe PWR RPV’s is guaranteed throughout the decade following the VD3 of the reactors, considering that EDF respects ASN demands with a view to comfort safety margins.