Digital Instrumentation and Control Systems Upgrades in Current Generation Nuclear Power Plants

2010 ◽  
Author(s):  
Steven A. Arndt
Keyword(s):  
United States ◽  
Cyber Security ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Plant Protection ◽  
The United States ◽  
Regulatory Compliance ◽  
Digital Systems

Over the past 20 years, the nuclear power industry in the United States (U.S.) has been slowly replacing old, obsolete, and difficult-to-maintain analog technology for its nuclear power plant protection, control, and instrumentation systems with digital systems. The advantages of digital technology, including more accurate and stable measurements and the ability to improve diagnostics capability and system reliability, have led to an ever increasing move to complete these upgrades. Because of the difficulties with establishing digital systems safety based on analysis or tests, the safety demonstration for these systems relies heavily on establishing the quality of the design and development of the hardware and software. In the United States, the U.S. Nuclear Regulatory Commission (NRC) has established detailed guidelines for establishing and documenting an appropriate safety demonstration for digital systems in NUREG-0800, “Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition,” Chapter 7, “Instrumentation and Controls,” Revision 5, issued March 2007 [1], and in a number of regulatory guides and interim staff guidance documents. However, despite the fact that the United States has a well-defined review process, a number of significant challenges associated with the design, licensing, and implementation of upgrades to digital systems for U.S. plants have emerged. Among these challenges have been problems with the quality of the systems and the supporting software verification and validation (V&V) processes, challenges with determining the optimum balance between the enhanced capabilities for the new systems and the desire to maintain system simplicity, challenges with cyber security, and challenges with developing the information needed to support the review of new systems for regulatory compliance.

scholarly journals Az atomerőművek üzemidejének meghosszabbítása az Egyesült Államokban és Magyarországon

2020 ◽  
Vol 15 (28) ◽  
pp. 344-375
Author(s):  
Anita Paulovics
Keyword(s):  
United States ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Operation Time ◽  
The United States ◽  
Legal Regulation ◽  
Time Limit ◽  
Energy Strategy ◽  
The Usa

This paper is about the legal regulation of the extension of the operation time of nuclear power plants.  In Hungary the most important document in this respect has been the National Energy Strategy analyzed in the paper. In Hungary, the legal regulation of the extension of the time limit of the operation-permit of nuclear power plants is modelled on that of the United States. For this reason, the paper examines the rules in force in the USA on the extension of the operation time.  It could be of interest for several European countries considering to extend the operation time of their nuclear power plants.

The Outline of the Five-Percent Power Uprate Project in Tokai-2

2010 ◽  
Author(s):  
Hitoshi Ohata ◽  
Toshikazu Nishibata ◽  
Tetsuya Onose
Keyword(s):  
United States ◽  
Electric Power ◽  
Power Output ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Thermal Power ◽  
The United States ◽  
European Countries ◽  
Electric Power Output

Reactor thermal power uprate (Power uprate) of operating light water reactors has long successful experiences in many nuclear power plants in the United States of America and European countries since late 1970’s. And it will be also introduced in Japan soon. This paper mainly describes the outline of the attempt of five-percent reactor thermal power uprate of Tokai No.2 Nuclear Power Station (Tokai-2) operated by the Japan Atomic Power Company (JAPC). It will be the leading case in Japan. Tokai-2 is GE type Boiling Water Reactor (BWR) of 1100 MW licensed electric power output and it commenced commercial operation in November 28, 1978. Power uprate is an effective approach for increasing electric power output. And it is recognized as one of the measures for effective and efficient use of existing Japanese operating nuclear power plants. It can contribute to inexpensive and stable electric power supply increase. Especially “Stretch Power Uprate (SPU)” requires only minor equipment modification or component replacement. It is also a countermeasure against global warming. Therefore it is a common theme to be accomplished in the near future for both Japanese electric power companies and government. JAPC started feasibility studies on power uprate in 2003. And in 2007, JAPC established a plan to achieve five-percent power uprate in Tokai-2 and announced this project to the public. This is a leading attempt in the Japanese electric power companies and it is the first case under the current Japanese regulatory requirements. In this plan, JAPC reflected lessons learned from preceding nuclear power plants in the United States and European countries, and tried to make most use of the performance of existing systems and components in Tokai-2 which have been periodically or timely renewed by utilizing more reliable and efficient design. JAPC plans to submit application documents to amend current License for Reactor Establishment Permit shortly. It will contain a complete set of revised safety analysis results based on the uprated reactor thermal power condition. Successful introduction of Tokai-2 power uprate will contribute to the establishment of regulatory process for power uprate in Japan and following attempts by other Japanese electric power companies.

License Renewal in the U.S. and Plant Life Management (PLIM)

2003 ◽  
Author(s):  
Garry G. Young ◽  
Mark A. Rinckel
Keyword(s):  
United States ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
The United States ◽  
Nuclear Industry ◽  
Life Management ◽  
Technical Requirements ◽  
Plant Life ◽  
License Renewal

License renewal of operating nuclear power plants in the United States has become one of the most successful nuclear industry activities in the past few years. It is anticipated that over 90% of the 103 operating nuclear power plants in the United States will pursue license renewal and seek an additional 20 years of operation. Some plants may pursue operation to 80 years or longer since the license renewal rule does not limit the operating life of a nuclear power plant. The requirements for renewing the operating license of a nuclear reactor in the United States are contained in Nuclear Regulatory Commission (NRC) Regulation 10 CFR Part 54, which addresses general, technical, technical specification, and environmental requirements. The most labor intensive element of the requirements are the technical requirements, which include addressing an integrated plant assessment (IPA) and time limited aging analyses (TLAA). The cost of performing the needed reviews and obtaining a renewed license ranges between $10M to $15M. The license renewal rule focuses on aging of passive long-lived components and aging management programs that manage those structures and components. The aging management programs credited to manage aging include both existing programs (e.g., ASME Section XI) and a few new programs (e.g., Reactor Vessel Internals Aging Management Program). Commitments to aging management programs for license renewal may be implemented and tracked through a comprehensive plant life management (PLIM) program. PLIM is the process to integrated equipment aging management with other plant activities to maximize plant value. PLIM can save the operating plant a significant amount of money by effectively planning and implementing component refurbishment and replacement. The ultimate decision to seek license renewal and continue operation is based on PLIM, which considers aging, safety, and economics.

A New Paradigm: Cycling Operations at Nuclear Power Plants in the United States

2013 ◽  
Author(s):  
Steven Lefton ◽  
Nikhil Kumar ◽  
Douglas Hilleman ◽  
Dwight Agan
Keyword(s):  
United States ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
The United States ◽  
Nuclear Plant ◽  
New Paradigm ◽  
Renewable Integration ◽  
Load Following ◽  
Relative Damage

Nuclear power plants are no longer immune to cycling operation. While certain nuclear power plants in Europe have been performing load following operation, this type of operation has largely been avoided in the United States. Due to increasing contribution of nuclear generation in the mix, European operators were forced to make modifications to increase the maneuverability of their nuclear generation assets. However, in the United States, nuclear generation is still a relatively smaller contributor (19%), but with rapid increase in renewable generation, some nuclear plans are being asked to operate at reduced power and cycle to lower power levels. These shutdowns are typically of a short-term duration on a weekend or in periods of high renewable megawatt generation. With most future renewable integration studies advocating for increased flexibility on the grid, nuclear generation maneuverability will allow system operators with another resource to mitigate and reduce system costs. This paper presents the results of a detailed study of a 1,150 MW boiling water reactor (BWR) nuclear plant when cycled to low loads. The authors present the relative damage of cycling to various reduced power levels 80% to 15% power levels compared to a cold startup and shutdown of a nuclear plant. An assessment was made of the systems that had fatigue damage and costs. We also discuss some of the limitations of cycling that a nuclear plant has and present and discuss recommendations to reduce damage and costs.

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