Toward strategies for protecting cooling and service water systems (CSWS) from overgrowth by colonial invertebrates with resting stages in their life cycle:Plumatella emarginata(Tentaculata) and UV - control vs. combating.Part II. Statoblast

2018 ◽  
Vol 51 (1) ◽  
pp. 44
Author(s):  
M. I. Orlova ◽  
E. V. Strogova ◽  
T. Lichi ◽  
M. A. Lurie ◽  
V. V. Kuz’min ◽  
...  
Keyword(s):  
Water Systems ◽  
Resting Stages ◽  
Service Water

Long Term Performance of PE4710 Materials in Disinfectant Treated Nuclear Raw Water Systems

2013 ◽  
Author(s):  
Alexander M. Summe ◽  
Douglas P. Munson ◽  
Kenneth Oliphant ◽  
Sarah Chung
Keyword(s):  
Power Plants ◽  
Slow Crack Growth ◽  
Life Time ◽  
Water Systems ◽  
Superior Performance ◽  
Mechanical Degradation ◽  
Service Water ◽  
Long Term Performance ◽  
Term Performance

Degradation of service water systems is a major issue facing nuclear power plants and many plants will require repair or replacement of existing carbon steel piping components. High-density polyethylene (HDPE) has been used in non-safety service water systems for over ten years and has demonstrated superior performance. However, there still exist knowledge gaps around material properties, inspectability, and long-term performance. Specifically, there is a lack of insight on the aging of HDPE piping in disinfectant treated service water systems. This paper summarizes the methodology and results of predicting the expected life time of HDPE piping exposed to oxidizing biocides in numerous end-use scenarios. The aging mechanism of concern is Stage III Chemical-Mechanical degradation, where the polymer is oxidized by biocides and then experiences slow crack growth (SCG). An Aging Model is used to provide general predictions of pipe service life. The results were analyzed for trends and limiting or sensitive operating parameters were identified. For most applications, the specific resin used in the model demonstrated good performance for lifetimes of well over 40 years.

Service Water Life Cycle Management

2008 ◽  
Author(s):  
Eric J. Houston ◽  
Arlene S. Rahn ◽  
George J. Licina
Keyword(s):  
Nuclear Power ◽  
Deterministic Model ◽  
Operating Time ◽  
Water System ◽  
Water Systems ◽  
Most Probable Number ◽  
Probable Number ◽  
System Integrity ◽  
Service Water ◽  
Water Piping

Nuclear plant service water systems are a critical part of the facility’s infrastructure. System integrity and performance are vital for plant reliability and essential to achieving a plant life of 40 years and beyond. Corrosion, fouling (macrofouling, microfouling and sedimentation) and other effects that are detrimental to the reliability of the service water system led to the issue of NRC Generic Letter 89-13 “Service Water System Problems Affecting Safety-Related Equipment.” This generic letter continues to be a fundamental guideline for safety related service water systems at all U.S. nuclear plants. The low temperature and pressure service water piping systems are primarily degraded by corrosion. Because of the complexity and random nature of corrosion processes, it is nearly impossible to develop a mathematically deterministic model that accurately predicts pipe wall loss. However, if statistical distributions are used to describe the various corrosion processes, mathematical algorithms that incorporate all of the distributions, iterated a statistically significant number of times, can be used to forecast the most probable number of leaks. This paper predicts the condition of service water piping at Kewaunee Nuclear Power Plant using the described model and includes the expected number of through-wall leaks as a function of operating time.

Technical Basis for Maximum Allowable Indentation Depths in HDPE Pipes for Proposed ASME Section III Code Case on Alternative Requirements to Appendix XXVI for Inspection and Repair

2019 ◽  
Author(s):  
Douglas Scarth ◽  
Prabhat Krishnaswamy ◽  
Phillip Rush ◽  
Douglas Munson
Keyword(s):  
High Density Polyethylene ◽  
Large Diameter ◽  
Cooling Water ◽  
Water Systems ◽  
Parent Material ◽  
Surface Conditions ◽  
Service Water ◽  
Piping Systems ◽  
Technical Basis ◽  
Hdpe Pipes

Abstract Mandatory Appendix XXVI of Section III of the ASME B&PV Code contains rules for the construction of Class 3 polyethylene pressure piping systems. The scope is limited to buried portions of Class 3 service water or buried portions of Class 3 cooling water systems, consisting of PE4710 High Density Polyethylene (HDPE) materials. The minimum Pennsylvania Notched Test (PENT) rating for the HDPE material is 2,000 hours. Appendix XXVI contains acceptance standards for the maximum allowable depths of gouges, cuts or other surface conditions that are characterized as indentations. The acceptance standards are considered to be very restrictive, in particular for large diameter HDPE pipes. Less restrictive maximum allowable indentation depths for pipes with a minimum PENT rating of 2,000 hours were developed based on use of results from tests performed on pressurized HDPE pipes containing flaws in the parent material. These maximum allowable indentation depths were implemented into the new Section III Code Case N-891 on alternative requirements to Appendix XXVI for inspection and repair. The technical basis for the maximum allowable indentation depths is described in this paper.

Update on Code Case N-755 Revision Class 3 Polyethylene Piping

2009 ◽  
Author(s):  
Matthew G. Golliet
Keyword(s):  
United States ◽  
Nuclear Regulatory Commission ◽  
Water Systems ◽  
Polyethylene Pipe ◽  
Nuclear Plants ◽  
Service Water ◽  
Asme Code ◽  
Pipe Replacement ◽  
Regulatory Commission ◽  
Essential Service

Nuclear plants have received United States Nuclear Regulatory Commission (NRC) approval to use polyethylene pipe in safety related systems such as essential service water systems. ASME Code Case N-755 is the basis for the utility requests. ASME Nuclear Code committees are developing a revision to provide clarification to the code case requirements and address NRC concerns. Polyethylene pipe replacement projects provide a solution to the age degradation issues such as corrosion and fouling of buried carbon steel pipe.

Tensile Testing and Material Property Development of High Density Polyethylene Pipe Materials

2008 ◽  
Author(s):  
Timothy M. Adams ◽  
Siegrid Hall ◽  
Rudolph J. Scavuzzo ◽  
Douglas Munson ◽  
Jeffrey W. Andrasik ◽  
...  
Keyword(s):  
Pressure Vessel ◽  
High Density Polyethylene ◽  
Tensile Testing ◽  
Water Systems ◽  
High Density ◽  
Test Program ◽  
Polyethylene Pipe ◽  
Cell Class ◽  
Service Water ◽  
Division 1

Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. High Density Polyethylene pipe has been used in non-safety service water systems for over nine years and found to perform well, but it is not currently permitted in the ASME Section III Boiler and Pressure Vessel Code, Division 1 for use in nuclear safety-related systems. To assist in the implementation of High Density Polyethylene pipe in the ASME Boiler and Pressure Vessel Code, Section III, Division 1 for Safety Class 3 applications, EPRI initiated a High Density Polyethylene pipe and pipe material testing program. This test program includes tensile testing and fatigue testing of High Density Polyethylene piping and piping components and the development of slow crack growth data. To determine the material and engineering properties needed, extensive tensile testing of specimens cut from High Density Polyethylene pipe was conducted. The initial tensile test program was conducted on PE 3408 with cell classification 345464C and a second, not yet finalized, phase was added to test PE 4710 with cell classification 445474C. The data developed during the testing were used to establish ultimate strain, elastic moduli, yield stress and yield strain values for both new and aged materials. Because extruded HDPE properties vary in the hoop and axial directions and the properties are highly affected by temperature, specimens were cut in both the hoop and axial directions and were tested at temperatures ranging from 50° F to 180° F. This paper provides a description and overview of the PE 3408 cell class 345464C test program. In addition, an overview and summary of the test results for the PE 3408 cell class 345464C are provided.

Bending Fatigue Testing of Pipe and Piping Components Fabricated From High Density Polyethylene Materials

2012 ◽  
Author(s):  
Timothy M. Adams ◽  
Douglas Munson ◽  
Siegrid Hall ◽  
Jeffrey W. Andrasik
Keyword(s):  
Pressure Vessel ◽  
High Density Polyethylene ◽  
Fatigue Testing ◽  
Water Systems ◽  
Fatigue Tests ◽  
High Density ◽  
Test Program ◽  
Bending Fatigue ◽  
Service Water ◽  
Division 1

Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. High Density Polyethylene piping has been used in non-safety service water systems for over nine years and found to perform well, and is now permitted in the ASME Section III Boiler and Pressure Vessel Code, Division 1 for use in nuclear safety-related systems. To assist in this implementation of High Density Polyethylene piping in the ASME Boiler and Pressure Vessel Code, Section III, Division 1 for Safety Class 3 applications, Electric Power Research Institute initiated a testing program that includes tensile and fatigue testing of High Density Polyethylene piping and components and the development of data to evaluate slow crack growth that can emanate from surface scratches. Straight cantilever bending fatigue tests on PE 4710 pipe with a minimum cell classification of 445474C were previously conducted and the results presented at the 2008 PVP Conference in Chicago, Illinois. The tests were designed to comply with the requirements for fatigue testing given in Mandatory Appendix II of the ASME Boiler and Pressure Vessel Code, Section III, Division 1. Based on the straight pipe tests, Stress Intensification Factors can be calculated for other piping components. This paper reports on follow-on testing of PE 4710 cell classification 445574C piping components. The fatigue testing results showed one of the unique characteristics of High Density Polyethylene piping: a significant decrease in material stiffness from the first few test cycles to a lower value that remains almost constant until failure. Thus, Stress at Failure vs cycles at failure curves and Stress Intensification Factors were determined twice: first based on the initial cycle results and again at the midlife of the fatigue tests. This paper provides a description and overview of the test program, testing methods and materials tested. In addition, an overview and summary of the test program results are provided.

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