A Review of the Current State of FPGA Systems in Nuclear Instrumentation and Control

Author(s):  
Phillip McNelles ◽  
Lixuan Lu

A Field Programmable Gate Array, or FPGA, is a form of integrated circuit that is programmed (configured) after it has been built. These devices have recently become a topic of interest for various applications in the nuclear field. Most of the recent work put into these FPGA systems is for the purpose of Instrumentation and Control (I&C) systems, but other applications include health physics, particle detectors, and pulse measurement systems. These new FPGA based systems are thought of as possible replacements for older, analog systems that are commonly used in Nuclear Power Plants (NPPs). Many of these systems are becoming obsolete, and it can be difficult to repair and maintain them. FPGAs possess certain advantages over traditional analog circuits, as well as microprocessors, for nuclear I&C applications. This paper provides an extensive literature survey on the current research into FPGA-based systems in NPP applications, such as shutdown systems, neutron monitors, and feedwater controls. Current plans and plans for future FPGA implementations are also discussed. Research from different countries in North America, Europe and Asia is discussed, covering a variety of NPP types (CANDU, Pressurized Water Reactors, Boiling Water Reactors, etc.). The main companies and organizations involved in the FPGA research and development are examined, and a direction for future research is presented.

Author(s):  
Jo¨rg Viermann ◽  
Andreas Friske ◽  
Jo¨rg Radzuweit

During operation of a Nuclear Power Plant components inside the RPV get irradiated. Irradiation has an effect on physical properties of these components. Some components have to be replaced after certain neutron doses or respectively after a certain operating time of the plant. Such components are for instance water channels and control rods from Boiling Water Reactors (BWR) or control elements, poisoning elements and flow restrictors from Pressurized Water Reactors (PWR). Most of these components are stored in the fuel pool for a certain time after replacement. Then they have to be packaged for further treatment or for disposal. More than 25 years ago GNS developed a system for disposal of irradiated core components which was based on a waste container suitable for transport, storage and disposal of Intermediate Level Waste (ILW), the so-called MOSAIK® cask. The MOSAIK® family of casks is subject of a separate presentation at the ICEM 09 conference.


Author(s):  
Phillip McNelles ◽  
Lixuan Lu ◽  
Marc-James Abi-Jaoude

A field-programmable gate array (FPGA) is a type of integrated circuit that is programmed after being manufactured. These FPGA-based systems are considered to be viable alternatives to replace many obsolete instrumentation and control (I&C) systems that are used in nuclear plants. This paper describes an FPGA-based lab-scale implementation of a postaccident monitoring system (PAMS), for a Westinghouse AP1000 reactor. This system will monitor vital parameters in the event of a serious reactor accident. The system reliability was analyzed using the dynamic flowgraph methodology (DFM). DFM was applied to fine-tune the design parameters by determining the potential causes of faults in the design.


2013 ◽  
Vol 10 (2) ◽  
pp. 6-10 ◽  
Author(s):  
Petr Pospíšil

Abstract Some commercial nuclear power plants have been permanently shut down to date and decommissioned using dismantling methods. Other operating plants have decided to undergo an upgrade process that includes replacement of reactor internals. In both cases, there is a need to perform a segmentation of the reactor vessel internals with proven methods for long term waste disposal. Westinghouse has developed several concepts to dismantle reactor internals based on safe and reliable techniques, including plasma arc cutting (PAC), abrasive waterjet cutting (AWJC), metal disintegration machining (MDM), or mechanical cutting. Mechanical cutting has been used by Westinghouse since 1999 for both Pressurized Water Reactors (PWR’s) and Boiling Water Reactors (BWR’s) and its process has been continuously improved over the years. The complexity of the work requires well designed and reliable tools. Different band saws, disc saws, tube cutters and shearing tools have been developed to cut the reactor internals. All of those equipments are hydraulically driven which is very suitable for submerged applications. Westinghouse experience in mechanical cutting has demonstrated that it is an excellent technique for segmentation of internals. In summary, the purpose of this paper will be to provide an overview of the Westinghouse mechanical segmentation process, based on actual experience from the work that has been completed to date.


Author(s):  
M. S. Kalsi ◽  
Patricio Alvarez ◽  
Thomas White ◽  
Micheal Green

A previous paper [1] describes the key features of an innovative gate valve design that was developed to overcome seat leakage problems, high maintenance costs as well as issues identified in the Nuclear Regulatory Commission (NRC) Generic Letters 89-10, 95-07 and 96-05 with conventional gate valves [2,3,4]. The earlier paper was published within a year after the new design valves were installed at the Pilgrim Nuclear Plant — the plant that took the initiative to form a teaming arrangement as described in [1] which facilitated this innovative development. The current paper documents the successful performance history of 22 years at the Pilgrim plant, as well as performance history at several other nuclear power plants where these valves have been installed for many years in containment isolation service that requires operation under pipe rupture conditions and require tight shut-off in both Pressurized Water Reactors (PWRs) and Boiling Water Reactors (BWRs). The performance history of the new valve has shown to provide significant performance advantage by eliminating the chronic leakage problems and high maintenance costs in these critical service applications. This paper includes a summary of the design, analysis and separate effects testing described in detail in the earlier paper. Flow loop testing was performed on these valves under normal plant operation, various thermal binding and pressure locking scenarios, and accident/pipe rupture conditions. The valve was designed, analyzed and tested to satisfy the requirements of ANSI B16.41 [9]; it also satisfies the requirements of ASME QME 1-2012 [10]. The results of the long-term performance history including any degradation observed and its root cause are summarized in the paper. Paper published with permission.


Author(s):  
Andriy Kovalenko ◽  
Ievgen Babeshko ◽  
Viktor Tokarev ◽  
Kostiantyn Leontiiev

This chapter describes an element base of new generation for NPP I&C, namely field programmable gate array (FPGA), and peculiarities of the FPGA application for designing safety critical systems. FPGA chips are modern complex electronic components that have been applied in nuclear power plants (NPPs) instrumentation and control systems (I&CSs) during the last 15-17 years. The advantages and some risks caused by application of the FPGA technology are analyzed. Safety assessment techniques of FPGA-based I&CSs and experience of their creation are described. The FPGA-based platform RadICS and its application for development of NPP I&CS is described.


Author(s):  
Jaehyun Cho ◽  
Yong-Hoon Shin ◽  
Il Soon Hwang

Although the current Pressurized Water Reactors (PWRs) have significantly contributed to the global energy supply, PWRs have not been considered as a trustworthy energy solution owing to its several problems; spent nuclear fuels (SNFs), nuclear safety, and nuclear economy. In order to overcome these problems, lead-bismuth eutectic (LBE) fully passive cooling Small Modular Reactor (SMR) system is suggested. It is possible to not only provide the solution of the problem of SNFs through the transmutation feature of LBE coolant, but also increase the safety and economy through the concepts of the natural circulation cooling SMRs. It is necessary to maximize the advantages (safety and economy) of this type of Nuclear Power Plants for several applications in future. Accordingly, objective of the study is to maximize the reactor core power while the limitations of shipping size, materials endurance, long-burning criticality as well as safety under Beyond Design Basis Events must be satisfied. Design limitations of natural circulating LBE-cooling SMRs are researched and power maximization method is developed based on obtained design limitations. It is expected that the results are contributed to reactor design stage with providing several insights to designers as well as the methods for design optimization of other type of SMRs.


Author(s):  
Jeffrey C. Poehler ◽  
Gary L. Stevens ◽  
Anees A. Udyawar ◽  
Amy Freed

Abstract ASME Code, Section XI, Nonmandatory Appendix G (ASME-G) provides a methodology for determining pressure and temperature (P-T) limits to prevent non-ductile failure of nuclear reactor pressure vessels (RPVs). Low-Temperature Overpressure Protection (LTOP) refers to systems in nuclear power plants that are designed to prevent inadvertent challenges to the established P-T limits due to operational events such as unexpected mass or temperature additions to the reactor coolant system (RCS). These systems were generally added to commercial nuclear power plants in the 1970s and 1980s to address regulatory concerns related to LTOP events. LTOP systems typically limit the allowable system pressure to below a certain value during plant operation below the LTOP system enabling temperature. Major overpressurization of the RCS, if combined with a critical size crack, could result in a brittle failure of the RPV. Failure of the RPV could make it impossible to provide adequate coolant to the reactor core and result in a major core damage or core melt accident. This issue affected the design and operation of all pressurized water reactors (PWRs). This paper provides a description of an investigation and technical evaluation regarding LTOP setpoints that was performed to review the basis of ASME-G, Paragraph G-2215, “Allowable Pressure,” which includes provisions to address pressure and temperature limitations in the development of P-T curves that incorporate LTOP limits. First, high-level summaries of the LTOP issue and its resolution are provided. LTOP was a significant issue for pressurized water reactors (PWRs) starting in the 1970s, and there are many reports available within the U.S. Nuclear Regulatory Commission’s (NRC’s) documentation system for this topic, including Information Notices, Generic Letters, and NUREGs. Second, a particular aspect of LTOP as related to ASME-G requirements for LTOP is discussed. Lastly, a basis is provided to update Appendix G-2215 to state that LTOP setpoints are based on isothermal (steady-state) conditions. This paper was developed as part of a larger effort to document the technical bases behind ASME-G.


Author(s):  
William Server ◽  
Timothy Hardin ◽  
Milan Brumovsky´

The International Atomic Energy Agency (IAEA) has had a series of reactor pressure vessel (RPV) structural integrity programs that started back in the 1970s. These Coordinated Research Projects most recently have focused on use of the Master Curve fracture toughness testing approach for RPV and other ferritic steel components and on the issue of pressurized thermal shock (PTS) in operating pressurized water reactors. This paper will provide the current status for these projects and discuss the implications for improved safety of key ferritic steel components in nuclear power plants (NPPs).


Author(s):  
Claude Faidy

Two major Codes are used for Fitness for Service of Nuclear Power Plants: one is the ASME B&PV Code Section XI and the other one is the French RSE-M Code. Both of them are largely used in many countries, partially or totally. The last 2013 RSE-M covers “Mechanical Components of Pressurized Water Reactors (PWRs): - Pre-service and In-service inspection - Surveillance in operation or during shutdown - Flaw evaluation - Repairs-Replacements parts for plant in operation - Pressure tests The last 2013 ASME Section XI covers “Mechanical components and containment of Light Water Reactors (LWRs)” and has a larger scope with similar topics: more types of plants (PWR and Boiling Water Reactor-BWR), other components like metallic and concrete containments… The paper is a first comparison covering the scope, the jurisdiction, the general organization of each section, the major principles to develop In Service Inspection, Repair-Replacement activities, the flaw evaluation rules, the pressure test requirements, the surveillance procedures (monitoring…) and the connections with Design Codes… These Codes are extremely important for In-service inspection programs in particular and essential tools to justify long term operation of Nuclear Power Plants.


Author(s):  
Emmanuelle Julli ◽  
Bertrand Lantes

EDF’s network of nuclear power plants (NPP) comprises 58 pressurized water reactors. Solid waste arising during plant operation (mainly VLLW, LLW and ILW) are conditioned and sent either to interim storage, an off site treatment plant for additional processing (e.g. the Centraco incinerator or the melting facilities of SOCODEI) or directly to one of the two final repositories operated by ANDRA, the French national radioactive waste management agency. The tracking system allows: - the checking of waste package characteristics against acceptance criteria of the final disposal facilities or off site treatment facilities; and - the transmission of the waste package data to ANDRA and SOCODEI. Since 1992, the EDF computer application DRA has been run on networked computers at EDF and ANDRA, and more recently at SOCODEI. DRA is also a key element in the management of radioactive waste. It allows a large range of inter comparisons to be made between the NPPs in operation and is thus the principal tool used optimize technical and economic performance. After 15 years of use, DRA was technically obsolete and could no longer be successfully developed to meet evolving regulatory requirements. It was therefore decided to completely replace the DRA system and in so doing to introduce new functionality.


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