Technical Basis for Proposed Revisions to ASME Code Case N-513 and Some Applications to Moderate Energy Piping

2006 ◽  
Author(s):  
Robert O. McGill ◽  
Nathaniel G. Cofie ◽  
Russell C. Cipolla ◽  
Guy DeBoo
Keyword(s):  
Original Version ◽  
System Operation ◽  
Short Term ◽  
Safety Issues ◽  
Asme Code ◽  
Moderate Energy ◽  
Technical Basis ◽  
Planar Flaw

Code Case N-513 provides evaluation rules and criteria for temporary acceptance of flaws, including through-wall flaws, in moderate energy piping. The application of the Code Case is restricted to Class 2 and 3 systems, so that safety issues regarding short-term system operation are minimized. The first version of the Code Case was published in 2000. Since then, there have been two revisions to the Code Case (N-513-1 [1] and N-513-2 [2]) that have been published by ASME. There is currently work underway to incorporate additional changes to the Code Case to make it easier to apply to through-wall, nonplanar flaws. The technical basis for the original version of the Code Case and the first revision, N-513-1, has been previously published [3]. This paper provides the technical basis for the changes in the second revision of the Code Case, N-513-2, and the proposed changes to a third revision. These changes specifically address exceptions taken by the NRC in the first version of the Code Case and more importantly provide flaw evaluation rules for through-wall, nonplanar flaws. The flaw evaluation rules for through-wall, nonplanar flaws are based on ASME Code Section III branch reinforcement rules and also a quasi planar flaw approach. These developments are described in the paper. In addition, practical examples involving the application of the Code Case to through-wall, nonplanar flaws are also provided.

Technical Basis for Proposed Fifth Revision to ASME Code Case N-513

2018 ◽  
Author(s):  
Dylan Cimock ◽  
Eric J. Houston ◽  
Russell C. Cipolla ◽  
Robert O. McGill
Keyword(s):  
Gate Valve ◽  
Evaluation Procedure ◽  
Straight Pipe ◽  
System Operation ◽  
Short Term ◽  
Valve Body ◽  
Safety Issues ◽  
Asme Code ◽  
Moderate Energy ◽  
Technical Basis

Code Case N-513 provides evaluation rules and criteria for temporary acceptance of flaws, including through-wall flaws, in moderate energy piping. The application of the Code Case is restricted to moderate energy, Class 2 and 3 systems, so that safety issues regarding short-term, degraded system operation are minimized. The first version of the Code Case was published in 1997. Since then, there have been four revisions to augment and clarify the evaluation requirements and acceptance criteria of the Code Case that have been published by ASME. The technical bases for the original version of the Code Case and the four revisions have been previously published [1, 2, and 3]. There is currently work underway to incorporate additional changes to the Code Case and this paper provides the technical basis for the changes proposed in a fifth revision. These changes include clarification for buried piping, investigation of various radii used in the Code Case, removal of the 0.1 limit on the flexibility characteristic for elbow flaw evaluation, and an update of the stress intensity factor parameters for circumferential through-wall flaws. In addition, a new flaw evaluation procedure is given for through-wall flaws in gate valve body ends. This procedure evaluates flaws in the end of the valve body as if in straight pipe. These changes and their technical bases are described in this paper. Clarifications and changes deemed editorial are not documented in this paper.

Technical Basis for Proposed ASME Code Case Based on N-513 for Higher Pressure Applications

2017 ◽  
Author(s):  
Robert O. McGill ◽  
Ronald J. Janowiak ◽  
Eric J. Houston ◽  
Do Jun Shim
Keyword(s):  
Structural Integrity ◽  
Temperature Limit ◽  
System Operation ◽  
Short Term ◽  
Safety Issues ◽  
Asme Code ◽  
Moderate Energy ◽  
Technical Basis ◽  
Thrust Forces ◽  
Case Based

Code Case N-513 provides evaluation rules and criteria for temporary acceptance of flaws, including through-wall flaws, in moderate energy piping. The application of the Code Case is restricted to Class 2 and 3 systems, so that safety issues regarding short-term system operation are minimized. The first version of the Code Case was published in 2000. Since then, there have been four revisions to the Code Case that have been published by ASME. The technical bases for the original version of the Code Case and the four revisions have been previously published. There is currently work underway to employ the methods given in N-513 for a new and separate Code Case for higher pressure piping applications. This paper provides the technical basis for the proposed Code Case that includes a structural integrity evaluation and consideration of potential jet thrust forces. In addition, discussion is provided on additional Code Case requirements considering the application to higher pressure systems in order to bolster defense-in-depth. Note that the proposed Code Case still maintains the temperature limit given in N-513.

Application Examples of ASME Code Case N-513 Implementation

2019 ◽  
Author(s):  
Robert O. McGill ◽  
Russell C. Cipolla ◽  
Eric J. Houston ◽  
Ronald J. Janowiak
Keyword(s):  
Gate Valve ◽  
Operating Experience ◽  
Straight Pipe ◽  
System Operation ◽  
Short Term ◽  
Valve Body ◽  
Safety Issues ◽  
Plant Safety ◽  
Asme Code ◽  
Moderate Energy

Abstract Code Case N-513 provides evaluation rules and criteria for temporary acceptance of flaws, including through-wall flaws, in moderate energy piping. The application of the Code Case is restricted to Class 2 and 3 systems, so that safety issues regarding short-term system operation are minimized. The first version of the Code Case was published in 1997. Since then, there have been five revisions to the Code Case that have been published by ASME. The Code Case has been used numerous times by utilities to avoid unscheduled shutdowns without impacting plant safety. Recent revisions of Code Case N-513 continue to expand its scope to piping components including elbows, reducers, branch tees and gate valve body ends. This paper provides three application examples of the Code Case implementation based on US plant operating experience. Specifically, detailed evaluations of through-wall leakage in straight pipe, a piping elbow and gate valve body end are provided. These examples will help facilitate Code Case implementation by future users.

Technical Basis for Proposed Fourth Revision to ASME Code Case N-513

2014 ◽  
Author(s):  
Robert O. McGill ◽  
Guy DeBoo ◽  
Russell C. Cipolla ◽  
Eric J. Houston
Keyword(s):  
Nuclear Regulatory Commission ◽  
Short Term ◽  
Safety Issues ◽  
Evaluation Procedures ◽  
The Us ◽  
Bent Pipe ◽  
Asme Code ◽  
Moderate Energy ◽  
Regulatory Commission ◽  
Technical Basis

Code Case N-513 provides evaluation rules and criteria for temporary acceptance of flaws, including through-wall flaws, in moderate energy piping. The application of the Code Case is restricted to moderate energy, Class 2 and 3 systems, so that safety issues regarding short-term, degraded system operation are minimized. The first version of the Code Case was published in 1997. Since then, there have been three revisions to augment and clarify the evaluation requirements and acceptance criteria of the Code Case that have been published by ASME. The technical bases for the original version of the Code Case and the three revisions have been previously published. There is currently work underway to incorporate additional changes to the Code Case and this paper provides the technical basis for the changes proposed in a fourth revision. These changes include addressing the current condition on the Code Case acceptance by the US Nuclear Regulatory Commission (NRC), clarification of the Code Case applicability limits and expansion of Code Case scope to additional piping components. New flaw evaluation procedures are given for through-wall flaws in elbows, bent pipe, reducers, expanders and branch tees. These procedures evaluate flaws in the piping components as if in straight pipe by adjusting hoop and axial stresses to account for the geometry differences. These changes and their technical bases are described in this paper.

Recent Applications of ASME Code Case N-513 for Evaluation of Nonplanar Leaking Flaws

2008 ◽  
Author(s):  
Robert O. McGill ◽  
Kari L. Den Herder ◽  
Daniel B. Patten ◽  
Steven P. Queen
Keyword(s):  
Evaluation Criteria ◽  
Nuclear Industry ◽  
Energy Class ◽  
Operating Cycle ◽  
Evaluation Procedures ◽  
Asme Code ◽  
Moderate Energy ◽  
Planar Flaw

ASME Code Case N-513, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping, provides evaluation rules for the temporary acceptance of flaws, including through-wall flaws, in moderate energy Class 2 or 3 piping without performing repair/replacement activities. The Code Case has gone through three revisions with the latest approved by ASME Section XI being N-513-2. The Code Case allows for evaluation of both planar and nonplanar flaws. The planar flaw evaluation uses the rules in Appendix C of ASME Section XI. The nonplanar flaw evaluation uses the procedure provided in Code Case N-480. This Code Case has been used widely in the nuclear industry ever since it was published. Its use is expected to grow with plant aging and especially since Revision 2 was recently endorsed by the NRC in Regulatory Guide 1.147 without condition. The paper describes three specific applications of the Code Case to accept leaking flaws in piping components for continued operation till the end of the operating cycle when repairs could be performed. The use of this Code Case thus avoided costly and unnecessary shutdown of the plants in these cases. The evaluation procedures using this Code Case for these instances are described in the paper.

Technical Basis for Acceptance of Flaws in Moderate Energy Class 2 and 3 Vessels and Tanks

2004 ◽  
Author(s):  
Pat L. Strauch ◽  
Warren H. Bamford ◽  
Sushil K. Daftuar
Keyword(s):  
Structural Integrity ◽  
Growth Curves ◽  
Nuclear Regulatory Commission ◽  
Operating Conditions ◽  
Energy Class ◽  
Asme Code ◽  
Moderate Energy ◽  
Leakage Monitoring ◽  
Regulatory Commission ◽  
Technical Basis

New procedures and acceptance criteria for the evaluation of degradation, including through-wall flaws, in moderate energy Class 2 and 3 vessels and tanks have been prepared for implementation within Section XI of the ASME Code. The provisions are contained in a proposed Code Case and are focused on the structural integrity margin of the vessel or tank against gross failure. The assessment of the degraded condition is based on the flaw evaluation procedures already established in ASME Section XI. Additional provisions for periodic inspection and leakage monitoring are included to assure that analysis assumptions are conservative for the operating conditions. The precedent for permitting operation with degraded components was established in United States Nuclear Regulatory Commission (NRC) Generic Letter 90-05 and Code Case N-513-1 for piping, as well as several NRC-accepted plant-specific relief requests associated with leaking tanks. The technical basis for the procedures is presented, and the objectives and scope of its application are explained. The basis for the analytical procedures follows from evaluation rules contained in ASME Section XI, Appendix A. Other issues regarding consequences of leakage, growth of degradation, and augmented inspections and surveillance are also addressed, as well as reference crack growth curves for stress corrosion cracking for conditions appropriate for application of these procedures.

scholarly journals Pharmacokinetic Interactions of Maraviroc with Darunavir-Ritonavir, Etravirine, and Etravirine-Darunavir-Ritonavir in Healthy Volunteers: Results of Two Drug Interaction Trials

2011 ◽  
Vol 55 (5) ◽  
pp. 2290-2296 ◽  
Author(s):  
Thomas N. Kakuda ◽  
Samantha Abel ◽  
John Davis ◽  
Julia Hamlin ◽  
Monika Schöller-Gyüre ◽  
...  
Keyword(s):  
Steady State ◽  
Healthy Volunteers ◽  
Potent Inhibitor ◽  
Cytochrome P450 3A ◽  
Short Term ◽  
Two Phase ◽  
Time Curve ◽  
Safety Issues ◽  
Concentration Time ◽  
Crossover Studies

ABSTRACTThe effects of darunavir-ritonavir at 600 and 100 mg twice daily (b.i.d.) alone, 200 mg of etravirine b.i.d. alone, or 600 and 100 mg of darunavir-ritonavir b.i.d. with 200 mg etravirine b.i.d. at steady state on the steady-state pharmacokinetics of maraviroc, and vice versa, in healthy volunteers were investigated in two phase I, randomized, two-period crossover studies. Safety and tolerability were also assessed. Coadministration of 150 mg maraviroc b.i.d. with darunavir-ritonavir increased the area under the plasma concentration-time curve from 0 to 12 h (AUC12) for maraviroc 4.05-fold relative to 150 mg of maraviroc b.i.d. alone. Coadministration of 300 mg maraviroc b.i.d. with etravirine decreased the maraviroc AUC12by 53% relative to 300 mg maraviroc b.i.d. alone. Coadministration of 150 mg maraviroc b.i.d. with etravirine-darunavir-ritonavir increased the maraviroc AUC123.10-fold relative to 150 mg maraviroc b.i.d. alone. Maraviroc did not significantly affect the pharmacokinetics of etravirine, darunavir, or ritonavir. Short-term coadministration of maraviroc with darunavir-ritonavir, etravirine, or both was generally well tolerated, with no safety issues reported in either trial. Maraviroc can be coadministered with darunavir-ritonavir, etravirine, or etravirine-darunavir-ritonavir. Maraviroc should be dosed at 600 mg b.i.d. with etravirine in the absence of a potent inhibitor of cytochrome P450 3A (CYP3A) (i.e., a boosted protease inhibitor) or at 150 mg b.i.d. when coadministered with darunavir-ritonavir with or without etravirine.

Effects of Cladding on Reactor Pressure Vessel Integrity Based on the Revised PTS Rule (10 CFR 50.61)

2009 ◽  
Author(s):  
Vikram Marthandam ◽  
Timothy J. Griesbach ◽  
Jack Spanner
Keyword(s):  
Thermal Shock ◽  
Pressure Vessel ◽  
Historical Perspective ◽  
Pressurized Thermal Shock ◽  
Asme Code ◽  
Potential Benefits ◽  
Vessel Integrity ◽  
Technical Basis ◽  
Reactor Pressure

This paper provides a historical perspective of the effects of cladding and the analyses techniques used to evaluate the integrity of an RPV subjected to pressurized thermal shock (PTS) transients. A summary of the specific requirements of the draft revised PTS rule (10 CFR 50.61) and the role of cladding in the evaluation of the RPV integrity under the revised PTS Rule are discussed in detail. The technical basis for the revision of the PTS Rule is based on two main criteria: (1) NDE requirements and (2) Calculation of RTMAX-X and ΔT30. NDE requirements of the Rule include performing volumetric inspections using procedures, equipment and personnel qualified under ASME Section XI, Appendix VIII. The flaw density limits specified in the new Rule are more restrictive than those stipulated by Section XI of the ASME Code. The licensee is required to demonstrate by performing analysis based on the flaw size and density inputs that the through wall cracking frequency does not exceed 1E−6 per reactor year. Based on the understanding of the requirements of the revised PTS Rule, there may be an increase in the effort needed by the utility to meet these requirements. The potential benefits of the Rule for extending vessel life may be very large, but there are also some risks in using the Rule if flaws are detected in or near the cladding. This paper summarizes the potential impacts on operating plants that choose to request relief from existing PTS Rules by implementing the new PTS Rule.

ASME Code-Case Proposal to Explicitly Quantify the Interaction Between the PWR Environment and Component Surface Finish

2017 ◽  
Author(s):  
Thomas Métais ◽  
Stéphan Courtin ◽  
Laurent De Baglion ◽  
Cédric Gourdin ◽  
Jean-Christophe Le Roux
Keyword(s):  
Fatigue Life ◽  
Surface Finish ◽  
Polished Surface ◽  
Design Curve ◽  
Fatigue Design ◽  
Wide Range ◽  
Asme Code ◽  
The Difference ◽  
The Uk ◽  
Technical Basis

Fatigue rules from ASME have undergone a significant change over the past decade, especially with the inclusion of the effects of BWR and PWR environments on the fatigue life of components. The incorporation of the environmental effects into the calculations is performed via an environmental factor, Fen, which is introduced in ASME BPV code-case N-792 [5], and depends on factors such as the temperature, dissolved oxygen and strain rate. Nevertheless, a wide range of factors, such as surface finish, have a deleterious impact on fatigue life, but their contribution to fatigue life is typically taken through the transition factors to build the fatigue design curve [2] and not in an explicit way, such as the Fen factor. The testing supporting the rules pertaining to Environmental Fatigue Correction Factor (Fen) Method in ASME BPV was performed on specimens with a polished surface finish and on the basis that the Fen factor was applicable without alteration of the historical practice of building the design curve through transition factors. The extensive amount of testing conducted and reported in References [2] and [7] (technical basis for ASME BPV current EAF rules) was used to propose a set of transition coefficients from the mean air curve to the design curve on one hand, and on the other hand to build a Fen factor expression, defined as the difference between the life in air and in PWR environments. The work initiated by AREVA in 2005 [9] [10] [11] demonstrated that there is a clear interaction between the two aggravating effects of surface finish and PWR environment for fatigue damage, which was not experimentally tested in the References [2] and [7]. These results have clearly been supported by testing carried out independently in the UK by Rolls-Royce and AMEC FW [12]. These results are all the more relevant as most NPP components do not have a polished surface finish. Most surfaces are either industrially polished or installed as-manufactured. It was concluded that this proposal could potentially be applicable to a wide range of components and could be of interest to a wider community. EDF/Areva/CEA have therefore authored a code-case introducing the Fen-threshold, a factor which explicitly quantifies the interaction between PWR environment and surface finish. This paper summarizes this proposal and provides the technical background and experimental work to justify this proposal.

scholarly journals Safety and Humoral Responses to SARS-CoV-2 mRNA Vaccination of Previously Infected and Naive Populations

2021 ◽  
Author(s):  
Shai Efrati ◽  
Merav Catalogna ◽  
Ramzia Abu Hamed ◽  
Amir Hadanny ◽  
Adina Bar-Chaim ◽  
...  
Keyword(s):  
Single Dose ◽  
Vaccine Dose ◽  
Medical Attention ◽  
Evaluation Procedure ◽  
Short Term ◽  
Serological Tests ◽  
Safety Issues ◽  
Infected Population ◽  
Group A ◽  
Humoral Responses

Abstract Since COVID-19 risk of reinfection is of great concern, the safety and efficacy of the mRNA-based vaccines in previously infected populations should be assessed. We studied 78 individuals previously infected with SARS-CoV-19, who received a single dose of BNT162b2 mRNA COVID-19 vaccine, and 1:2 ratio matched infection-naïve cohort who received two injections. The evaluation procedure included symptom monitoring, and serological tests. Among the post-infected population, the median IgG-S response after the first vaccine dose was 2260 AU/ml, compared to 238 AU/ml after the second vaccine injection in the infection naive group. A strong correlation was demonstrated between IgG-S level before vaccination, and the corresponding responses after a single vaccine dose (r = 0.8, p < 0.001) in the post infected population. Short-term severe symptoms that required medical attention were found in 6.8% among the post-infected individuals, while none were found in the infection naïve population. Our data suggest that a single vaccine dose is sufficient to induce an intense immune response in post-infected population regardless of seropositivity. Although some short-term safety issues were observed compared to the infection naïve population, a single dose regimen can be considered safe in post-infected populations.

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