A proposed aging management program for alkali silica reactions in a nuclear power plant
Introduction
It is a matter of public record that Seabrook nuclear power plant (NPP) appears to be suffering from alkali silica reaction (ASR) in a localized zone of its subbasement. Drawing exclusively from publicly available information from the Agency wide Document Access and Management System (ADAMS), the authors provide an unsolicited personal and independent opinion on the management of this problem based primarily on the senior author's experience with ASR (Saouma and Perotti, 2006, Saouma et al., 2007, Saouma et al., 2014, Puatatsananon and Saouma, 2013, Saouma, 2013).
First ASR will be briefly explained, then the presence of ASR in nuclear power plants will be discussed, followed by the role of irradiation on ASR. Issues pertaining to the life-extension of NPP will be discussed in general, followed by a factual presentation of the role of ASR in Seabrook NPP (as published in ADMAS). The paper will conclude with the authors personal comments on some of the actions presently taken, and finally what they would personally recommend.
Section snippets
What is ASR
ASR was first identified by Stanton (1940) as a cause for concrete deterioration and is likely the leading cause of dam concrete deterioration. This slowly evolving internal concrete damage causes millions of dollars in damage worldwide, given that no (economically) feasible method is available to stop the reaction. More recently, there has been evidence of ASR in nuclear power plants (see below).
Alkali–silica reaction is an acid–base one. The acid reactant is silica in the solid state, the
ASR in nuclear power plants
Despite the lack of publicity, some nuclear power plants reactors are starting to show signs of ASR.
In Japan, the (reinforced concrete) turbine generator foundation at Ikata No. 1 NPP (owned by Shihoku Electric Power) exhibits ASR expansion and has thus been the subject of many studies. Takatura et al. (2005a) reports on the field investigation work underway: location, extent of cracking, variation in concrete elastic modulus and compressive strength, expansion in sufficient detail to
Role of irradiation on ASR
It has long been known that irradiation affects concrete properties; the classical work by Hilsdorf et al. (1978) remains pertinent today given the complexity of conducting supportive experiments.
The possibility that nuclear irradiation can significantly increase the reactivity of silica-rich aggregates (hence the potential for ASR) was first raised by Ichikawa and Koizumi (2002). Let's begin by the author's summary of the state of knowledge in 2002:
- •
Gamma rays do not affect concrete properties
Life extension
According to the Atomic Energy Act of 1954 (NUREG-0980, 2013), and Nuclear Regulatory Commission (NRC) regulations, the operating licenses for commercial power reactors are issued for 40 years and can be renewed for an additional 20 years, with no limit to the number of renewals. The original 40-year license term was selected on the basis of economic and antitrust considerations rather than technical limitations. Henceforth, many plants have sought (and obtained) a 20-year life extension. In
Reported issue
This section will provide detailed information on the first reported nuclear power plant in the U.S. known to possibly suffer from ASR. All information reported has been gathered exclusively from the ADAMS, the official record-keeping system through which the U.S. Nuclear Regulatory Commission provides access to publicly available documents. It is worth mentioning that ML121250588 (2012) does outline the regulatory framework and general acceptance criterion for NRC oversight and review.
- Description
NextEra
Conclusions
In summary, the authors agree that indeed “Seabrook ASR affected structures are operable but degraded” (ML121220109, 2012), however given the uncertainty of the rate and extent of degradation a major challenge is to anticipate the evolution of the reaction, and more importantly, its impact on the structural integrity of the reactor (both serviceability and strength). Answer to this critical question requires an uncompromising understanding of the State of the Art to properly and safely propose
References (84)
- et al.
Lattice discrete particle modeling (LDPM) of alkali silica reaction (ASR) deterioration of concrete structures
Cement Concrete Compos.
(2013) - et al.
Laboratory assessment of alkali contribution by aggregates to concrete and application to concrete structures affected by alkali–silica reactivity
Cement Concrete Res.
(2002) Chemistry of alkali–silica reaction and testing of aggregates
Cement Concrete Compos.
(2005)- et al.
Rapid evaluation of alkali–silica reactivity of aggregates using a nonlinear resonance spectroscopy technique
Cement Concrete Res.
(2010) - et al.
Alkali release from feldspars into pore solutions
Cement Concrete Res.
(2003) - et al.
Thermodynamic and kineic approach to the alkali-silica reaction: Part I. Concepts
Cement Concrete Res.
(1992) - et al.
Comprehensive concrete fracture tests: description and results
Eng. Fract. Mech.
(2013) - et al.
Modified model of alkali-silica reaction
Cement and Concrete Research
(2007) - et al.
Effect of applied stresses on alkali–silica reaction induced expansions?
Cement Concrete Res.
(2006) - et al.
Mixed mode fracture of cementitious bimaterial interfaces: Part I. Experimental results?
Eng. Fract. Mech.
(1998)
Building Code Requirements for Reinforced Concrete (ACI 318-83)
The static and fatigue strength of reinforced concrete beams affected by alkali–silica reaction?
ACI Mater. J.
Minimum Design Loads for Buildings and Other Structures. Technical Report
Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
Lab to Test Seabrook's Concrete Problems
Approaches developed by edf with respect to the apprehension of risks of internal expansion of the concrete on nuclear structures: Management of operating power plants and prevention for new power plants.
Next-Generation Performance-Based Seismic Design Guidelines. Technical Report
Report on the Diagnostics, Prognosis, and Mitigation of Alkali–Silica Reaction (ASR) in Transportation Structures. Technical Report FHWA-HIF-09-004
FHWA ASR Reference Center
Ageing management of French NPP civil work structures
Seabrook Station Nuclear Plant License Advancing
Numerical simulation of concrete deterioration: Part I. Chloride diffusion?
ACI Mater. J.
Numerical simulation of concrete deterioration: Part II. Steel corrosion and concrete fracture?
ACI Mater. J.
Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements?
Cement Concrete Res.
The Effects of Nuclear Radiation on the Mechanical Properties of Concrete. Technical Report SP 55-10
Effect of nuclear radiation on alkali–silica reaction?
J. Nucl. Sci. Technol.
Possibility of radiation-induced degradation of concrete by alkali–silica reaction of aggregates?
J. Nucl. Sci. Technol.
Shear strength of ASR-deteriorated RC members and shear reinforcing effect of repair by adding rebar.
Behavior of concrete under biaxial stresses?
ASCE J. Eng. Mech. Div.
Apports Combinés de l’Experimentation et de la Modélisation àla Comprehension del’Alcali-Réaction et de ses Effets Mécaniques
Assessment of alkali–silica reaction damage through quantification of concrete nonlinearity
Mater. Struct.
Flexural and shear capacity of PRC beams damaged by combined deterioration due to ASR and corrosion
Evaluation of crack propagation in ASR damaged concrete based on image analysis.
Structural Assessment of Seabrook Station. Technical Report ML121160349
Impact of Alkali Silica Reaction on Seabrook Concrete Structure. Technical Report ML121160422
Meeting Summary Regarding Concrete Degradation Held on April 23, 2012. Technical Report ML121220109
Cited by (25)
Evaluation of ASR in concrete using acoustic emission and deep learning
2021, Nuclear Engineering and DesignCitation Excerpt :The gel exerts pressure on the aggregate and cement matrix, and causes cracking. The common structures, which are exposed to ASR are bridges (Bach et al., 1993; Bakker, 2008; Clark, 1989; Schmidt et al., 2014), concrete dams (Campos et al., 2018; Plusquellec et al., 2018), nuclear power plants, and nuclear waste containments (Saouma and Hariri-Ardebili, 2014; Soltangharaei et al., 2018a; Takakura et al., 2005; Tcherner and Aziz, 2009). Because of the safety and radioprotection functions of concrete structures in nuclear power plant, the effects of ASR to current and long-term operations must be thoroughly addressed.
A hybrid FE-based predictive framework for ASR-affected structures coupled with accelerated experiments
2021, Engineering StructuresCitation Excerpt :Alkali silica reaction (ASR) is an acid-base reaction, first identified by Stanton [1] as a cause for concrete deterioration. It includes concrete expansion, material degradation, and subsequently slowly evolving internal concrete damage causing millions of dollars in damage worldwide to the structure and infra-structures [2]. The concept of ASR was a hot topic over the past 30 years, and thousands of papers were published each one addressing a particular complexity of this phenomenon (among them diagnosis and prognosis).
Ultimate pressure capacity of nuclear reactor containment buildings under unaged and aged conditions
2018, Nuclear Engineering and DesignCitation Excerpt :Sulfate attack is a chemical reaction between sulfate ions such as sodium sulfate or magnesium sulfate and calcium-silicate-hydrate (C-S-H) or concrete paste (Lee et al., 2005). Alkali-silica reaction is a reaction between silica in the solid state and potassium/or sodium hydroxide, forming a calcium potassium silicate hydrate or calcium sodium silicate hydrate (Saouma and Ardebili, 2014). These two typical degradation mechanisms affect the mechanical properties of concrete (Lee et al., 2005).
Condition assessment and management protocols for concrete infrastructure affected by internal swelling reactions: Challenge and research needs
2023, Life-Cycle of Structures and Infrastructure Systems - Proceedings of the 8th International Symposium on Life-Cycle Civil Engineering, IALCCE 2023