scholarly journals An Assessment of Simplified vs. Detailed Methodologies for SSI Analyses of Deeply Embedded Structures

2004 ◽  
Author(s):  
J. Xu ◽  
C. Miller ◽  
C. Hofmayer ◽  
H. Graves
Keyword(s):  
Performance Assessment ◽  
Nuclear Power ◽  
National Laboratory ◽  
Response Spectra ◽  
Nuclear Regulatory Commission ◽  
Brookhaven National Laboratory ◽  
Beam Model ◽  
Simplified Approach ◽  
Embedded Structures ◽  
Different Depths

Sponsored by the US Nuclear Regulatory Commission (NRC), Brookhaven National Laboratory (BNL) is carrying out a research program to develop a technical basis to support the safety evaluation of deeply embedded and/or buried (DEB) structures as proposed for advanced reactor designs. In this program, the methods and computer programs established for the assessment of soil-structure interaction (SSI) effects for the current generation of light water reactors are evaluated to determine their applicability and adequacy in capturing the seismic behavior of DEB structures. This paper presents an assessment of the simplified vs. detailed methodologies for seismic analyses of DEB structures. In this assessment, a lump-mass beam model is used for the simplified approach and a finite element representation is employed for the detailed method. A typical containment structure embedded in a soil profile representative of a typical nuclear power plant site was utilized, considering various embedment depths from shallow to full burial. BNL used the CARES program for the simplified model and the SASSI2000 program for the detailed analyses. The calculated response spectra at the key locations of the DEB structure are used for the performance assessment of the applied methods for different depths of burial. Included in the paper are: 1) the description of both the simplified and detailed models for the SSI analyses of the DEB structure, 2) the comparison of the analysis results for the different depths of burial between the two methods, and 3) the performance assessment of the analysis methodologies for SSI analyses of DEB structures. The resulting assessment from this study has indicated that simplified methods may be capable of capturing the seismic response for much deeper embedded structures than would be normally allowed by the standard practice.

scholarly journals An Approach for Assessing Structural Uplifting Using Blast Motions

2008 ◽  
Author(s):  
Jinsuo Nie ◽  
Jim Xu ◽  
Charles H. Hofmayer ◽  
Syed A. Ali
Keyword(s):  
Coal Mine ◽  
Nuclear Power ◽  
Large Scale ◽  
Ground Motions ◽  
National Laboratory ◽  
Field Tests ◽  
Field Measurements ◽  
Nuclear Regulatory Commission ◽  
Brookhaven National Laboratory ◽  
Ground Acceleration

When a nuclear power plant (NPP) structure is subjected to beyond-design-basis seismic motions, a localized nonlinear effect on the soil-structure system is attributed to separations between the structure and the surrounding soils such as basemat uplift. Experiments involving field tests for real seismic events are usually difficult because of the low probability for large earthquakes at any particular site. To this end, the magnitudes of blast-induced ground motions at a coal mine have been found to be predicatable and can reach very large values. An approach has been developed to investigate whether the strong ground motions recorded at this coal mine can be used to evaluate the basemat uplift effect. This approach involves the use of a scaled ground motion to establish the relationship between the basemat uplift and the peak ground acceleration (PGA). This paper summarizes the field measurements for the ground motions at a coal mine by the Japan Nuclear Safety Organization (JNES) and a method using large scale finite element analyses for basemat uplift assessment performed by Brookhaven National Laboratory for the US Nuclear Regulatory Commission.

scholarly journals Review of Practice for Deeply Embedded/Buried NPP Structures Subject to Seismic Loadings

2004 ◽  
Author(s):  
J. Xu ◽  
C. Miller ◽  
C. Hofmayer ◽  
H. Graves
Keyword(s):  
National Laboratory ◽  
Earth Pressure ◽  
Nuclear Regulatory Commission ◽  
Brookhaven National Laboratory ◽  
Nuclear Containment ◽  
The Us ◽  
Reactor Building ◽  
Seismic Loadings ◽  
Knowledge And Practice ◽  
Regulatory Commission

Motivated by many design considerations, several conceptual designs for advanced reactors have proposed that the entire reactor building and a significant portion of the steam generator building will be either partially or completely embedded below grade. For the analysis of seismic events, the soil-structure interaction (SSI) effect and passive earth pressure for these types of deeply embedded structures will have a significant influence on the predicted seismic response. Sponsored by the US Nuclear Regulatory Commission (NRC), Brookhaven National Laboratory (BNL) is carrying out a research program to assess the significance of these proposed design features for advanced reactors, and to evaluate the existing analytical methods to determine their applicability and adequacy in capturing the seismic behavior of the proposed designs. This paper summarizes a literature review performed by BNL to determine the state of knowledge and practice for seismic analyses of deeply embedded and/or buried (DEB) nuclear containment type structures. Included in the paper is BNL’s review of the open literature of existing standards, tests, and practices that have been used in the design and analysis of DEB structures. The paper also provides BNL’s evaluation of available codes and guidelines with respect to seismic design practice of DEB structures. Based on BNL’s review, a discussion is provided to highlight the applicability of the existing technologies for seismic analyses of DEB structures and to identify gaps that may exist in knowledge and potential issues that may require better understanding and further research.

Overview of Seismic Issues in Design Certification and Combined License Application Reviews

2009 ◽  
Author(s):  
Jim Xu ◽  
Sujit Samaddar
Keyword(s):  
Seismic Design ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Response Spectra ◽  
Nuclear Regulatory Commission ◽  
Lessons Learned ◽  
Site Specific ◽  
License Application ◽  
Standard Design

The U.S. Nuclear Regulatory Commission (NRC) established a new process for licensing nuclear power plants under Title 10 of the Code of Federal Regulations (10 CFR) Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants,” which provides requirements for early site permits (ESPs), standard design certifications (DCs), and combined license (COL) applications. In this process, an application for a COL may incorporate by reference a DC, an ESP, both, or neither. This approach allows for early resolution of safety and environmental issues. The COL review will not reconsider the safety issues resolved by the DC and ESP processes. However, a COL application that incorporates a DC by reference needs to demonstrate that pertinent site-specific parameters are confined within the safety envelopes established by the DC. This paper provides an overview of site parameters related to seismic designs and associated seismic issues encountered in DC and COL application reviews using the 10 CFR Part 52 process. Since DCs treat the seismic design and analysis of nuclear power plant (NPP) structures, systems, and components (SSC) as bounding to future potential sites, the design ground motions and associated site parameters are often conservatively specified, representing envelopes of site-specific seismic hazards and parameters. For a COL applicant to incorporate a DC by reference, it needs to demonstrate that the site-specific hazard in terms of ground motion response spectra (GMRS) is enveloped by the certified design response spectra of the DC. It also needs to demonstrate that the site-specific seismic parameters, such as foundation-bearing capacities, soil profiles, and the like, are confined within the site parameter envelopes established by the DC. For the noncertified portion of the plant SSCs, the COL applicant should perform the seismic design and analysis with respect to the site-specific GMRS and associated site parameters. This paper discusses the seismic issues encountered in the safety reviews of DC and COL applications. Practical issues dealing with comparing site-specific features to the standard designs and lessons learned are also discussed.

Immersion and Leach Tests on Solidified Decontamination Wastes From Dresden Unit 1

1981 ◽  
Vol 6 ◽  
Author(s):  
Robert E. Barletta ◽  
Jay W. Adams ◽  
Richard E. Davis
Keyword(s):  
Nuclear Power ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Sample Volume ◽  
Deionized Water ◽  
Organic Liquids ◽  
Weight Changes ◽  
Release Rates ◽  
Saturated Water ◽  
Water Saturated

ABSTRACTIn order to provide technical support to the NRC, Brookhaven National Laboratory has performed leach tests and immersion tests using organic liquids and organic saturated water of concentrated decontamination waste solidified using a vinyl ester-styrene binder.The leach tests measured the release of Fe, Ni, and Co from these forms in deionized water, groundwater, and seawater. After 64 days, the mean fraction released normalized by V/S for iron was 5.1 ± 1.9 × 10−3 cm in deionized water, 7.1 ± 1.1 × 10−3 cm in groundwater, and 9.0 ± 3.2 × 10−3 cm in seawater. For nickel, 64 day release rates observed were 4.6 ± 1.6 × 10−3 cm, 4.6 ± 1.0 × 10−3 cm, and 5.9 ± 0.6 × 10−3 cm in deionized water, groundwater, and seawater, respectively. After 50 days, the 59 Fe release rates were 5.9 ± 0.7 × 10−3, 4.8 ± 2.4 × 10−3, and 2.8 ± 1.0 × 10−3 cm in deionized water, groundwater, and seawater, respectively. For 60Co, the 50 day releases in the three respective leaching media were 6.0 ± 1.7 × 10−3 cm, 6.8 ± 1.0 × 10−3 cm, and 2.3 ± 0.2 × 10−3 cm.Immersion tests of waste forms prepared at a solidification demonstration held at the Dresden Nuclear Power Station were conducted in toluene, xylene, and water saturated with toluene and xylene. During immersion of samples in the pure organics, large changes in sample volume and weight were observed. Total weight changes of 9.6 ± 0.3% and 21.6 ± 0.7% were observed after 839 hours of immersion in xylene and toluene, respectively. Air drying of the samples led to an overall weight loss of 23.5 ± 0.7% for xylene and 35.6 ± 0.6% for toluene. Qualitatively, similar changes were observed for immersion tests using organic saturated water. Severe sample deterioration was observed in this case, however. The cause of this deterioration is not known.

Side‐looking underground radar (SLUR): Physical modeling and case history

Geophysics ◽  
1998 ◽  
Vol 63 (6) ◽  
pp. 1925-1932 ◽  
Author(s):  
Jeffrey J. Daniels ◽  
James Brower
Keyword(s):  
Cross Sections ◽  
Ground Penetrating Radar ◽  
Physical Modeling ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Plan View ◽  
Different Depths ◽  
Ground Penetrating ◽  
Oriented Object ◽  
Horizontal Layers

A modification of conventional surface ground‐penetrating radar (GPR) was conceived, tested, and successfully applied in the field at Brookhaven National Laboratory (BNL) to investigate waste pits. The modified GPR method consists of making measurements along a traverse line in a sloping trench with the radar’s antenna oriented at an angle of up to 45° from the horizontal. The direction of propagation of the electromagnetic field for this configuration is not vertical, and the amount of energy scattered from objects that are oriented vertically relative to the energy scattered from horizontal layers is increased. This fundamental feature of side‐looking underground radar (SLUR) measurements is illustrated by physical modeling. Measurements made along parallel trenches that are offset at different distances from a vertically oriented object provides GPR cross‐sections with a primary plane of investigation that intersects the vertical feature at different depths. SLUR was used at BNL in conjunction with conventional surface GPR measurements (displayed as 3-D blocks and plan‐view time slices) to enhance the vertical definition and improve the depth estimates of the waste pits.

Seismic Fragility Analysis of a Condensate Storage Tank With Multiple Uncertain Degradation Scenarios

2012 ◽  
Author(s):  
Jinsuo R. Nie ◽  
Joseph I. Braverman ◽  
Charles H. Hofmayer ◽  
Young-Sun Choun ◽  
Min Kyu Kim ◽  
...  
Keyword(s):  
Storage Tank ◽  
Nuclear Power ◽  
Power Plants ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Passive Components ◽  
Age Related ◽  
Effects Of Aging

The Korea Atomic Energy Research Institute (KAERI) and Brookhaven National Laboratory (BNL) are continuing a collaborative effort to achieve a better understanding of the effects of aging on the performance of structures and passive components (SPCs) in nuclear power plants (NPPs). This paper presents a seismic fragility analysis of a condensate storage tank (CST) with multiple degradation scenarios that are treated in a non-perfectly correlated manner. The analysis utilizes a set of optimum Latin Hypercube samples to characterize the deterioration behavior of the fragility capacity as a function of age-related degradations. This study is an addition to the previous study summarized in an ICONE19 paper entitled “Seismic Fragility Analysis of a Degraded Condensate Storage Tank” [1], which considered individual degradation scenarios and multiple degradations occurring in a perfectly correlated manner.

scholarly journals Characteristics of the Vertical and Horizontal Response Spectra of Earthquakes in the Jeju Island Region

2021 ◽  
Vol 11 (22) ◽  
pp. 10690
Author(s):  
Jun-Kyoung Kim ◽  
Soung-Hoon Wee ◽  
Seong-Hwa Yoo ◽  
Kwang-Hee Kim
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Strong Dependence ◽  
Response Spectra ◽  
Nuclear Regulatory Commission ◽  
The United States ◽  
Jeju Island ◽  
Ground Acceleration ◽  
Resonance Frequencies ◽  
Earthquake Series

In this study, we evaluated the response spectra of 24 earthquake series, which includes 15 from the Kumamoto earthquake series and 9 from the Pohang earthquake series, and explored the effects of earthquake magnitude on the resonance frequencies of structures and buildings. Furthermore, the observations of this study were compared with the design response spectra, Regulatory Guide 1.60 (The United States Nuclear Regulatory Commission, 1973) for Korean nuclear power plants, and with the Korean Building Code (MOLIT, 2016, hereinafter referred to as KBC 2016) for general structures and buildings. The response spectra, after normalization with reference to the peak ground acceleration (PGA), were derived using a total of 423 horizontal and vertical accelerations. It was observed that the shapes of the horizontal and vertical response spectra were strongly dependent on the magnitude of the earthquake and the resonance frequency. Given the strong dependence of the response on the magnitude, it is suggested to consider magnitude > ML ~ 6.0 when establishing design response spectra. Compared to inland areas, a fairly higher amplitude of response at significantly lower frequency ranges could be attributed to the local geological environment of Jeju Island, which was formed by a surface volcano eruption and the distribution of unconsolidated Pleistocene marine sediments in the Jeju area. It is necessary to study the characteristic influence of layers with low shear wave velocity distributed in the Jeju region on seismic responses more rigorously while considering the frequency band and amplitudes at the surface of Jeju. The resonance frequencies of general low-rise and mid-rise buildings by the brief formula and those by design response spectra both suggested by KBC 2016 were overlapped, and these indicated that the seismic hazard could be much higher on general buildings in the Jeju region than in inland areas. Lastly, it is necessary to make the design standard criteria for Reg. Guide 1.60 and KBC 2016 more conservative in the lower frequency range of higher than 0.6 Hz and 2.0–6.0 Hz, respectively, which is significantly lower than those of the inland area, and to establish improved design response spectra with site-specific seismic design standards by referencing large amounts of qualitative data from the region around the Korean Peninsula.

Evaluation of Ultrasonic Phased-Array for Detection of Planar Flaws in High-Density Polyethylene (HDPE) Butt-Fusion Joints

2016 ◽  
Author(s):  
Matthew S. Prowant ◽  
Kayte M. Denslow ◽  
Traci L. Moran ◽  
Richard E. Jacob ◽  
Trenton S. Hartman ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Phased Array ◽  
National Laboratory ◽  
Cooling Water ◽  
Pacific Northwest National Laboratory ◽  
Nuclear Regulatory Commission ◽  
High Density

The desire to use high-density polyethylene (HDPE) piping in buried Class 3 service and cooling water systems in nuclear power plants is primarily motivated by the material’s high resistance to corrosion relative to that of steel alloys. The rules for construction of Class 3 HDPE pressure piping systems were originally published as an alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME BPVC) in ASME Code Case N-755 and were recently incorporated into the ASME BPVC Section III as Mandatory Appendix XXVI (2015 Edition). The requirements for HDPE examination are guided by criteria developed for metal pipe and are based on industry-led HDPE research and conservative calculations. Before HDPE piping will be generically approved for use in U.S. nuclear power plants, the U.S. Nuclear Regulatory Commission (NRC) must have independent verification of industry-led research used to develop ASME BPVC rules for HDPE piping. With regard to examination, the reliability of volumetric inspection techniques in detecting fusion joint fabrication flaws against Code requirements needs to be confirmed. As such, confirmatory research was performed at the Pacific Northwest National Laboratory (PNNL) from 2012 to 2015 to assess the ability of phased-array ultrasonic testing (PAUT) as a nondestructive evaluation (NDE) technique to detect planar flaws, represented by implanted stainless steel discs, within HDPE thermal butt-fusion joints. All HDPE material used in this study was commercially dedicated, 305 mm (12.0 in.) nominal diameter, dimension ratio (DR) 11, PE4710 pipe manufactured with Code-conforming resins, and fused by a qualified and experienced operator. Thermal butt-fusion joints were fabricated in accordance with or intentionally outside the standard fusing procedure specified in ASME BPVC. The implanted disc diameters ranged from 0.8–2.2 mm (0.03–0.09 in.) and the post-fabrication positions of the discs within the fusion joints were verified using normal- and angled-incidence X-ray radiography. Ultrasonic volumetric examinations were performed with the weld beads intact and the PA-UT probes operating in the standard transmit-receive longitudinal (TRL) configuration. The effects of probe aperture on the ability to detect the discs were evaluated using 128-, 64-, and 32-element PA-UT probe configurations. Results of the examinations for each of the three apertures used in this study will be discussed and compared based on disc detection using standard amplitude-based signal analysis that would typically be used with the ultrasonic volumetric examination methods found in ASME BPVC.

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