The current upper limit of hydrostatic test pressure in KT-3 of ASME Sec. VIII Division 3 is determined by general yielding through the thickness obtained by Nadai’s equation with a design factor of 0.866 (= 1.732/2). On the other hand, the upper limit of hydrostatic test pressure in 4.1.6 of the ASME Sec. VIII Division 2 is determined by general yielding through the thickness with a design factor of 0.95. In cases where a ratio of hydrostatic test pressure to design pressure of 1.43 similar to PED (Pressure Equipment Directive) is requested, the upper limit of hydrostatic test pressure may be critical for vessel design when material with a ratio of yield strength to tensile strength less than 0.7 is used. In order to satisfy the requirements in KT-3, it is necessary to decrease design pressure or increase wall thickness. Therefore, it is proposed to change the design factor of intermediate strength materials to obtain the upper limit of hydrostatic test pressure. In this paper, a new design factor to obtain the upper limit of hydrostatic test pressure is proposed and the validity of this proposal was investigated by burst test results and elastic-plastic analysis.

The paper describes the general approach followed by AFCEN, the French Society for Design, Construction and In-Service Inspection Rules for Nuclear Island Components, in developing the RCC-M code from the technical and organizational points of views. The changes that the RCC-M Subcommittee has introduced into the 2016 Edition of RCC-M code are explained and commented upon. The main activities of the RCC-M Subcommittee have been in achieving and demonstrating conformity of the code with French regulation and making comparisons with other codes and standards. The paper highlights how industrial experience is being integrated into the RCC-M code and how conformity with the essential safety requirements of the European Pressure Equipment Directive has been demonstrated. The processes for updates, interpretations or inquiries are also addressed.

The paper will cover the general approach of welding requirements in RCC-M 2012Ad2014[1], from a technical and quality point of view. It will be clarified how EN standards has been taken in account, mainly due to developments pushed by Pressure Equipment Directive (97/23/EC)[2] in Europe. It will be explained how nuclear activities for welding need to restrain the use of standards developed firstly for the needs of non nuclear industries. New ISO/ EN standards related to welding (ISO 9606-1, ISO 15614-1, ISO 3834) will be considered, and how they may lead to international cohabitation, compatibilities or harmonization, between nuclear codes.

The bolted joint by its simple nature, can be tightened by anyone who can lift a spanner. This has led over the years to a lack of respect and the acceptance of un-managed assembly and tightening. The results have been lack of control over the key goal — a joint that performs reliably and safely in service. ASME has recently updated a number of key standards such as PCC-1-2010 [1] and a parallel initiative is ongoing in Europe [2]. Both have the same end goal to recognize the importance and need for careful control and diligent application of standards for bolted joints on critical pressurized systems. The paper will compare the developments in Europe with those in ASME and state the case for continued development and application of standards to reduce the level of leakage and failures associated with bolted flanged joints. Under Europe Safety Directives there is a growing recognition that the Pressure Equipment Directive [3] does not treat the bolted joint equally with the Welded joint this anomaly will be explained in the paper.

The experimental nuclear power reactor based on the fusion principle, tested in the framework of the international project ITER, will be installed in France. In Europe, all pressure equipments must comply with the Pressure Equipment Directive 97/23/CE (PED) and satisfy the Essential Safety Requirements (ESRs) set out in its Annex I. For pressure equipments not conforming to European harmonized standards it must be demonstrated that all ESRs are satisfied. Nuclear pressure equipments are not within the scope of PED but those installed on the French soil must comply with the French Order dated December 2005 on nuclear pressure equipment (ESPN). As far as ESRs are concerned, ESPN gives complementary requirements to PED. For this international project and for sake of consistency, ASME Codes were chosen for the construction of all pressure equipments. For each selected Code, its compliance with PED and ESPN legislations has been examined. All applicable ESRs have been identified as “totally”, partially” or “not complied” together with the paragraph of the Code under review that fulfill the ESR. When needed complementary specifications were established. This presentation focuses on the ASME BPV Code Section VIII Division 2 and on the B31.3 Code, excluding Level N1 nuclear equipment aspects.

This paper describes the changes made to existing version of the Structural Design Criteria for In-vessel Components (SDC-IC) within the ITER project, as a result of the revision and update process carried out recently. Several ITER components, referred to as In-vessel Components, are located inside the ITER Vacuum Vessel: (a) Blanket System: shields the Vessel and Magnets from heat and neutron fluxes; (b) Divertor: extracts heat, helium ash and impurities from the plasma; (c) Fuelling: gas injection system to introduce fuel into the Vacuum Vessel; (d) Ion Cyclotron Heating & Current Drive System: transfers energy to the plasma by electromagnetic radiation; (e) Electron Cyclotron Heating & Current Drive System: uses radio waves to heat to the plasma; (f) Neutral Beam Heating & Current Drive System: accelerates Deuterium particles into the plasma; (g) Lower Hybrid Heating & Current Drive System: drives electric current into the plasma; (h) Diagnostics: measurement systems to control plasma performance, and further understand plasma physics; (i) Test Blankets: demonstrate techniques for ensuring tritium production within the tokamak. ITER In-vessel Components will be subjected to special operating and environmental conditions (neutron radiation, high heat fluxes, electromagnetic forces, etc.). The effects of irradiation on them, including embrittlement, swelling and creep, are not addressed in the existing commercial codes. These conditions are different from conditions in fission reactors and create challenging issues related to the design of these components. For this reason the Structural Design Criteria for ITER In-vessel Components (SDC-IC) [1] was developed for design purposes. SDC-IC was based mainly on the RCC-MR [2] code, and included rules for assessment of effect of neutron irradiation. In 2008 some issues were identified: (1) Some parts had not been fully prepared to cover all needed areas for design; (2) Some important topics needed to be improved; (3) New editions of codes on pressure equipment had been published; (4) No manufacturing rules were included, so consistency between manufacturing rules to be used and design rules in SDC-IC needed to be demonstrated; (5) Compliance with the ESP (French Decree concerning the Pressure Equipment Directive 97/23/EC for non-nuclear pressure vessels) [3] and ESPN (French Order applicable for pressure vessels intended for nuclear facilities) [4] needed to be addressed. The work carried out for Fusion For Energy (European Union’s Joint Undertaking for ITER) is: (a) Modification of design rules, incorporating rules from recently developed codes, and development of specific design rules to cover ITER specific issues and operational conditions; (b) Demonstration of consistency between design rules in SDC-IC and european standards used for manufacturing, in particular EN 13445 [5]; identifying areas where consistency is not provided; (c) Assessment of the compliance with the Essential Safety Requirements of the French Regulations (ESP and ESPN).

The design and construction rules for mechanical components of LWR nuclear islands (RCC-M) constantly evolve to reflect the needs of the industry with the objective to fulfill the regulatory demands. Each year, an addendum is thus prepared by Afcen. The December 2008 addendum includes in particular new grades for products procurement, evolutions on destructive and non destructive examination provisions, consideration of new editions of standards, improvements of text for an easier application. For a better consistency with regulatory demands, technical code requirements have been updated (pressure test, overpressure protection, examination requirements or material properties), and in certain cases, provisions have been shifted in non-mandatory appendices established for various regulatory contexts for a better adaptation to applications abroad. In parallel, the conditions for consistency with the European Pressure Equipment Directive (PED) and the French Nuclear Pressure Equipment regulation (ESPN Order dated December 12, 2005) have been deepened and a comparison work was done in the context of the MDEP (Multinational Design Evaluation Procedure initiative of OECD) with equivalent ASME code provisions. The paper will present the content of the 2008 addendum of RCC-M, and the present status of these two studies on regulatory conformance and international comparisons, as well as some orientations for further evolutions.

In the context of the issuing of the European Pressure Equipment Directive (PED) the objective of which is to suppress trade barriers within the European Union, a new regulation has been issued in France for nuclear pressure equipment. This text makes reference to the Decree transposing the PED, while completing these provisions by supplementary requirements having the objective to provide a very high level of integrity guarantee for equipments which are the most important for safety, and to cover the prevention of radioactive release risks. Referencing the PED, and including specific provisions, the Ministerial Order implies that Codes and specifications should be updated in the following two domains: • that of the conformity of Codes and Standards used, generally inspired from the ASME Code Section III, with the essential safety requirements of the PED, • that of the respect of the complementary provisions brought by the new Order applying to nuclear pressure equipments (ESPN). This paper presents the more significant conclusions of this work and the resulting amendments of the RCC-M Code, introduced by the 2007 edition to that Code. It also presents the main evolutions integrated in the 2007 edition of the RCC-M to cover projects needs and integrate the consequences of the evolutions of standards to which the code refers. As a general rule, the RCC-M makes the largest use of European and ISO standards in order to facilitate its application in various industrial and regulatory contexts.

Standardization related to the European Pressure Equipment Directive 97/23/EC (PED) is of considerable importance. European Member States must permit the placing on the market of pressure equipment and assemblies at the date of application of this Directive since 29 May 2002, and permit such equipment and assemblies to be put into service since this date. The economic significance of the pressure equipment sector for the common European market is made clear by the fact, that approximately every tenth subject presently dealt with by the European Standardization Committee (CEN) is directly or indirectly linked to the PED. On a European level, a total of 19 Technical Committees in CEN and 9 Technical Committees in ECISS (European Committee for Iron and Steel Standardization) are involved in standardization relating to the Directive 97/23/EC. Three committees are dealing with flanges, gaskets, bolts and valves. On a international level two technical committees standardize flanges and bolts.

The Pressure Equipment Directive (97/23/EC) [PED] was adopted by the European Parliament and the European Council in May 1997. Following a two-and-a-half year transition phase, the PED became mandatory on May 29, 2002. Its purpose is to harmonize national laws of Member States regarding the design, manufacture, testing and conformity assessment of pressure equipment and their assemblies, and thus ensure the free placing on the market and putting into service of pressure equipment within the European Economic Area.

The harmonized standard EN 13445 [1] provides the means by which a manufacturer can claim presumption of conformity to the essential safety requirements of the Pressure Equipment Directive. In addition, it aims to bring together the best available European pressure vessel technology in a single unified document. Use of this standard however, has still to be established in an industry which has been slow to accept change, especially when other well-known codes remain in use. This paper highlights the main technical differences between EN 13445-3 and other international standards (principally PD5500 [2] and ASME VIII [3]) and considers the implications for industry, research organisations and the various code-writing bodies.

Development of the European Pressure Equipment Directive 97/23/EC, better known as the “PED was set into motion on April 19, 1994 when the European Parliament delivered its opinion at the first reading on the proposal for a “European Parliament and Council Directive on the approximation of the laws of the Member States concerning pressure equipment”. The Parliament and Council adopted the Directive, bearing that official title, on May 29, 1997. On May 29, 2002, the PED became mandatory in the countries of the European Economic Area (EEA).

Publication of the main European pressure equipment standards in May 2002 coincided with the end of the transition period for introduction of the Pressure Equipment Directive. This comprehensive series of standards, replacing the many former national standards in Europe, extends to some 300 standards and another 600 supporting standards. Completing the program and further developing these standards continues to involve extensive collaborative effort, selecting the best practices from the enlarged European Union and elsewhere in the world. Account is being taken of technical and commercial considerations, design by analysis techniques, and best practices in permanent joining, non-destructive testing and materials manufacture. In addition, research work has been carried out to justify or confirm radical approaches to the entire process of design, manufacture, installation and operation of pressure equipment. This paper updates the further progress with some of the standards, in particular in relation to the use of aluminium and cast iron materials in pressure vessels, test pressures, further developments in the use of design techniques, and aspects of creep design. Mention is also made of the ways in which practical experience is being fed back into the standards-making processes to ensure that economic aspects continue to be balanced with safety considerations within an overall structured intellectual framework.