NUREG/CR-6916

Hydraulic Transport of

Coating Debris

A Subtask of GSI-191

Naval Surface Warfare Center,

Carderock Division 

U.S. Nuclear Regulatory Commission

Office of Nuclear Regulatory Research

Washington, DC 20555-0001
 

 

 NUREG/CR-6916

Hydraulic Transport of

Coating Debris

A Subtask of GSI-191 

Manuscript Completed: October 2006

Date Published: December 2006

Principal Investigators: T. Fu and A. Fullerton1

Prepared by

A. Fullerton, T. Fu, D. Walker and J. Carneal1

Contributor:

J.A. Fort

2

Naval Surface Warfare Center, Carderock Division 1

9500 MacArthur Boulevard

West Bethesda, MD 20817

Pacific Northwest National Laboratory

2

902 Battelle Boulevard

Richland, WA 99352 

E. Geiger, NRC Project Manager

Prepared for

Division of Fuel, Engineering and Radiological Research 

Office of Nuclear Regulatory Research

U.S. Nuclear Regulatory Commission

Washington, DC 20555-0001

NRC Job Code N-6198 
ii 

Page Intentionally Blank. 
iii 

ABSTRACT 

Generic Safety Issue (GSI)-191 “Assessment of Debris Accumulation on PWR Sump 

Performance” raised the concern of debris transport to pressurized-water-reactor (PWR) sump 

screens following a loss-of-coolant accident (LOCA) and subsequent impact to emergency core 

cooling systems (ECCS) and containment spray systems (CSS) during ECCS sump 

recirculation. Failed coatings debris is one potential source for debris transported to the ECCS 

sump screens. This document describes a limited number of tests conducted to study the 

transportability of coatings debris (chips) in ambient temperature water, at specific conditions of 

uniform flow. It is intended that the transport parameters observed in these tests could be used 

as the basis for the evaluation of coating chip transport under plant specific conditions. The 

transport characteristics of coatings particulates were not examined in these experiments as 

fine particulate are assumed to transport. 

 

Five coating systems, typical of coatings applied to equipment and structures located in the 

contaminant buildings of PWR plants, were tested. The effects of chip size, shape, density, 

thickness, stream velocity, water saturation, and thermal curing on transportability were 

examined through two types of tests – quiescent settling and transport within uniform flow. The 

quiescent settling tests were conducted in a 0.3 m wide by 0.3 m long by 1.2 m deep (one foot 

wide by one foot long by four foot deep) acrylic tank. The goals of the quiescent water tests 

were to determine: (1) the time necessary for coating chips dropped onto the water surface to 

break the surface and begin to sink (time-to-sink tests), and (2) to determine the terminal 

settling velocity of submerged coating chips (terminal velocity tests). The transport tests were 

conducted in a 0.91 m wide by 0.91 m deep by 9.1 m long (three foot wide by three foot deep by 

thirty foot long) acrylic flume suspended in a large circulating water channel. The goal of the 

transport tests was to characterize the behavior of coating chips in moving water. The tests 

consisted of a tumbling-velocity test to study the behavior of coating chips placed on the flume 

floor and a steady-state velocity test to study the behavior of coatings debris released into the 

moving stream below the water surface. A statistically meaningful number of data tests were 

conducted for each coating type, chip size and chip shape in each test category in order to more 

accurately quantify observations. 

The quiescent tests demonstrated that, when dropped onto the water surface, coating chips with 

a density close to that of water tended to remain on the surface indefinitely and heavier chips 

tended to sink almost immediately. The tumbling velocity tests demonstrated that all but the 

lightest chips and curled chips remained in their initial position at stream velocities in excess of 

0.09 m/s (0.3 ft/s). The steady-state velocity test demonstrated that, at a uniform water velocity 

of 0.06 m/s (0.2 ft/s), all but the lightest chips settled to the bottom before reaching the end of 

the flume. 
iv 

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v 

FOREWORD 

The U.S. Nuclear Regulatory Commission (NRC) is engaged in activities associated with 

resolving Generic Safety Issue (GSI) 191, AAssessment of Debris Accumulation on PWR Sump 

Performance.@ GSI-191 raised the concern that debris, generated by a loss-of-coolant accident 

(LOCA), could be transported to the emergency core cooling system (ECCS) sump screens 

during sump recirculation, thereby blocking flow area and reducing the ability of the ECCS 

and containment spray system (CSS) to cool the reactor core and containment building. 

Failed coatings have been identified as one potential source of debris that may transport 

to the ECCS sump screens. Therefore, the NRC sponsored research at the Carderock Division 

of the Naval Surface Warfare Center to assess the potential for coatings debris to transport 

to the sump screens. The primary objective of these tests was to examine the buoyancy 

(time-to-sink), terminal settling velocity, tumbling velocity, and steady-state transport velocity 

of the coating chips. 

This study involved the following two distinct types of tests to examine the behavior of coating 

chips in water: 

1. Settling tests in a quiescent water tank, 0.3 meter long by 0.3 meter wide by 1.2 meter 

deep (1 foot x 1 foot x 4 feet). The purposes of these tests were to (1) examine the time 

required for coatings chips to break the surface of the water and begin to sink 

when dropped onto the surface from a height of 0.3 meter (1 foot), and (2) to record 

the terminal settling velocity. 

2. Hydraulic transport tests in a flume, 9.1 meter long by 0.9 meter wide by 0.9 meter deep 

(30 feet x 3 feet x 3 feet). The purposes of these tests were to (1) determine the water 

velocity required to lift coating chips and tumble them along the floor, and (2) observe 

the transportability of coating chips submerged in water moving at a constant velocity of 

0.06 meter (0.2 foot) per second and at the tumbling velocity specific to the coating chip 

sample-lot being tested. 

The coating systems selected for testing were a single-coat alkyd, a two-coat epoxy, 

a zinc primer/epoxy top coat, a six-coat epoxy and a three-layered all-epoxy concrete system. 

These coatings were selected from the large number of containment coating system/supplier 

combinations because it was not feasible to test every coating system from every supplier. 

Moreover, the selected coating systems are considered to be representative of the range 

of chemical formulations, coating thicknesses, densities, and weights of coatings used in 

nuclear power plants. Further, to ensure that suppliers of the original coating systems were 

represented in the tests, the supply of samples was distributed among the three remaining 

major nuclear coating suppliers. The coatings were received at the test facility in sheets and 

were prepared for testing by breaking them into smaller pieces (by hand or using a commercial 

blender) to replicate the random shapes and sizes observed in failed coatings. The chips were 

further classified into three size groups C 0.4 mm to 0.8 mm, 3.2 mm to 6.4 mm, and 25 mm to 

51 mm (1

'64" to 1'32", c" to 3", and 1" to 2") C for testing. Samples of 25 mm to 51 mm (1" to 

2") chips were also curled and heat treated to study the effect of curling and exposure to 

elevated temperatures, respectively, on transport characteristics. In addition, in the quiescent 

water tests, some chips were pre-soaked to study the effect of water saturation due to 

containment sprays or the pipe break on coating chip buoyancy and terminal velocity. 

vii 

CONTENTS 

Abstract...........................................................................................................................iii 

Foreword......................................................................................................................... v 

Executive Summary ......................................................................................................xiii 

Abbreviations .................................................................................................................xv 

1 Introduction........................................................................................................... 1 

1.1 Background .......................................................................................................... 1 

1.2 Objective .............................................................................................................. 1 

1.3 Testing Approach ................................................................................................. 2 

2 Coating Chip Characteristics ................................................................................ 3 

2.1 Coatings Tested ................................................................................................... 3 

2.2 Coating Chip Size Selection................................................................................. 3 

2.3 Coating Film Preparation...................................................................................... 3 

2.4 Sample Conditioning ............................................................................................ 4 

2.4.1 Presoaking............................................................................................................ 4 

2.4.2 Sizing and Shaping............................................................................................... 5 

2.4.3 Thermal Curing ..................................................................................................... 8 

2.5 Coating Density Verification ................................................................................. 8 

2.6 Coating Thickness Verification ............................................................................. 9 

3 Quiescent Testing............................................................................................... 11 

3.1 Test Description ................................................................................................. 11 

3.1.1 Time-to-Sink Test ............................................................................................... 11 

3.1.2 Terminal Velocity Test ........................................................................................ 12 

3.2 Test Facility ........................................................................................................ 12 

3.3 Time-to-Sink Test Results .................................................................................. 14 

3.3.1 Large Chips ........................................................................................................ 14 

3.3.2 Small Chips......................................................................................................... 14 

3.4 Terminal Velocity Test Results ........................................................................... 17 
viii 

4 Transport Testing................................................................................................ 21 

4.1 Transport Test Facility........................................................................................ 21 

4.2 Summary of Testing Procedure.......................................................................... 24 

4.2.1 Tumbling Velocity ............................................................................................... 24 

4.2.2 Steady-State Velocity ......................................................................................... 25 

4.3 Velocity Mapping ................................................................................................ 25 

4.4 Test Results ....................................................................................................... 26 

4.4.1 Tumbling Velocity Test........................................................................................ 26 

4.4.2 Steady-State Transport Test............................................................................... 27 

5 Conclusions ........................................................................................................ 31 

6 Refrences ........................................................................................................... 33 

Appendices 

A Procedure For Sizing Coating Chips..................................................................A-1 

B Procedure For Time-To-Sink Tests....................................................................B-1 

C Results For Time-To-Sink Tests ....................................................................... C-1 

D Procedure For Terminal Velocity Tests............................................................. D-1 

E Procedure For Tumbling Velocity Tests.............................................................E-1 

F Procedure for Transport Test.............................................................................F-1 

G Results For Steady-State Transport Test ......................................................... G-1 

H Coating Systems Sample Preparation .............................................................. H-1 

 
ix 

Figures 

Figure 2-1 Cumulative Distribution for 25.4 to 50.8 mm (1 to 2 inches) Flat Chips ........ 6 

Figure 2-2 Cumulative Distribution for 25.4 to 50.8 mm (1 to 2 inches) Curled Chips.... 6 

Figure 2-3 Cumulative Distribution for 3.175 to 6.35 mm (1/8 to 1/4 inches).................. 6 

Figure 2-4 Cumulative Distribution for 0.40 to 0.79 mm (1/64 to 1/32 inches)................ 7 

Figure 2-5 Cumulative Distribution for Continuous Size Distribution .............................. 7 

Figure 2-6 Microscope Image of E3C............................................................................. 9 

Figure 3-1 Quiescent Test Facility Vertical Tank.......................................................... 13 

Figure 3-2 Tensiometer................................................................................................ 13 

Figure 3-3 Percent of 25.4 to 50.8 mm (1 to 2 in) Flat Chips Sinking Initially............... 15 

Figure 3-4 Percent of 25.4 to 50.8 mm (1 to 2 in) Curled Chips Sinking Initially .......... 15 

Figure 3-5 Percent of 3.2 to 6.35 mm (1/4 to 1/8 inches) Chips Sinking Initially .......... 16 

Figure 3-6 Percent of 0.4 to 0.8 mm (1/32 to 1/64 in) Chips Sinking Initially................ 16 

Figure 3-7 Terminal Velocity for “As-Received” Chips.................................................. 19 

Figure 3-8 Terminal Heat-Treat Effects........................................................................ 19 

Figure 3-9 Terminal Velocity Trend With Chip Size and Weight per Unit Area............. 20 

Figure 4-1 Circulating Water Channel Facility .............................................................. 21 

Figure 4-2 Transport Flume in Circulating Water Channel (overhead view)................. 22 

Figure 4-3 Transport Flume in Circulating Water Channel (side view) ......................... 22 

Figure 4-4 Schematic of Transport Flume.................................................................... 23 

Figure 4-5 Filter for Transport Flume............................................................................ 23 

Figure 4-6 Bulk Tumbling Velocity Results................................................................... 27 
x 

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xi 

Tables 

Table 2-1 Coatings Systems for Quiescent Settling and Transport Testing...................... 4 

Table 2-2 Sample Density ......................................................................................................... 9 

Table 2-3 Coating Thicknesses .............................................................................................. 10 

Table 3-1 Quiescent Test Matrix ............................................................................................ 11 

Table 3-2 Terminal Velocity Results ...................................................................................... 18 

Table 4-1 Tumbling Velocity Test Matrix ................................................................................ 24 

Table 4-2 Steady State Transport Test Matrix ..................................................................... 25 

Table 4-3 Tumbling Velocity Test Results............................................................................. 26 

Table 4-4 Transport Test Results (Metric Units).................................................................. 28 

Table 4-5 Transport Test Results (English Units)................................................................ 29 
xii 

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xiii 

EXECUTIVE SUMMARY 

A series of coating chip transport experiments were performed in support of the resolution of 

Generic Safety Issue (GSI)-191, “Assessment of Debris Accumulation on PWR Sump 

Performance.” The concern raised by GSI-191 is the transport and accumulation of debris to 

pressurized water reactor (PWR) sump screens following a loss-of-coolant accident (LOCA) and 

subsequent impact to emergency core cooling systems (ECCS) and containment spray systems 

(CSS). During the recirculation phase of a PWR design basis LOCA, the (ECCS) and CSS 

circulate cooling water from the containment sump pool, through heat exchangers, to the reactor 

core and containment spray header. During the LOCA, there is a potential for debris 

accumulated in the containment building to transport to the recirculation sump and inhibit the 

flow of water necessary for ECCS and CSS operation. 

To determine if failed coatings can be a potential source for debris transported to the ECCS 

sump screens, the United States Nuclear Regulatory Commission (NRC) sponsored research to 

characterize the transportability of coating debris (chips). The research is intended to support 

the evaluation of the effect of coating chip accumulation on ECCS performance. The 

experiments were performed between September 2005 and January 2006 at the US Naval 

Surface Warfare Center, Carderock Division in the facility’s Specialized Research and 

Advanced Development Laboratory and the Circulating Water Channel. The transport of 

coatings particulates was not investigated in this research project as the particulates are 

assumed to remain in suspension and, therefore, transport. 

The transportability of chips from five different coating systems was examined. They were: a 

single coat alkyd, an inorganic zinc primer with epoxy topcoat, a two-coat epoxy, a six-coat 

epoxy and an all-epoxy sealer/surfacer/top-coat concrete system. These coatings were 

selected from an extensive list of coatings used at nuclear power plants and are considered to 

represent the physical properties of the bulk of the coatings used. When possible, coating 

materials were obtained from the original major coatings suppliers. 

The experiments examined the effects of chip size, chip shape, chip density, chip thickness, and 

fluid velocity on chip transportability through quiescent settling testing and transport testing. 

The goals of the quiescent settling tests were to (1) determine the time necessary for floating 

coating chips to break the water surface and begin sinking (time-to-sink tests), and (2) 

determine the steady-state settling rate of submerged coating chips (terminal velocity tests). 

The transport tests were performed to characterize the behavior of coating chips in flowing 

water. The specific objective was to measure the stream velocity required to initiate and sustain 

chip movement along the floor of the test channel (tumbling velocity) and the tendency of chips 

to transport when placed in a stream moving at a velocity of 0.06 m/s (0.2 ft/s). 

The quiescent settling experiments were conducted in a 0.3 m wide by 0.3 m long by 1.2 m 

deep (one foot wide by one foot long by four foot deep) clear acrylic tank. For each coating 

sample type, the motion of 100 chips was observed in groups of 5 for large chips and 10 for 

small chips. The transport experiments were conducted in a 9.1 m (30 ft) long, open ended, 

acrylic flume having a 0.91 m (3 ft) by 0.91 m (3 ft) cross-section. The flume was suspended in 

a larger circulating-water channel capable of developing a range of steady velocities from zero 

to 4.6 m/s (15.2 ft/s). The tank was submerged so that the depth of water in the tank was 0.76 

m (30 in.). To collect chips that transported, a filter was placed at the down-stream end of the 

flume. The filter consisted of three sections to allow capture and segregation of chips that 

transported at the surface (top 0.08 m (3 in.)), in suspension (middle 0.6 m (24 in.)), and along 
xiv 

the bottom of the tank (bottom 0.08 m (3 in.)). Coating chips were released into the water at a 

point 2.44 m (8 ft) downstream of the flume entrance and chip motion was recorded with 

cameras positioned along the length of the flume. The transport tests were repeated until 50 

chips of each sample category were recorded. 

The quiescent tests demonstrated that (1) light-weight coating chips, specifically alkyd chips, 

dropped onto the water surface tended to remain on the surface indefinitely, (2) a large percent 

of the heavy coating chips (six-coat epoxy and epoxy system for concrete) sank immediately, 

and (3) a small percent of the medium-weight coating chips (two-coat epoxies, zinc/epoxy 

systems) sank immediately. The tumbling velocity tests demonstrated that the highest bulk 

tumbling velocity (approximately 0.43 m/s (1.4 ft/s)) was associated with the heaviest flat 

coating chips. The curled and light chips had the lowest tumbling velocities with the bulk of the 

chips tumbling at 0.08 m/s (0.27 ft/s) and 0.14 m/s (0.46 ft/s) for curled two-coat epoxy and onecoat alkyd coating systems, respectively. In the steady-state velocity test, at a uniform water 

velocity of 0.06 m/s (0.2 ft/s), all but the lightest chips came to rest at the bottom of the flume 

within a short distance of the release point. Only a small percentage of the medium sized alkyd 

chips transported to the end of the test flume by floating on the surface. 
xv 

ABBREVIATIONS 

ADV – acoustic Doppler velocimeter 

ALK –low density alkyd, single layer coating 

ANSI – American National Standards Institute 

ASTM – American Society for Testing Materials 

CSS - containment spray system 

CWC – circulating water channel 

DFT – dry film thickness 

DBA – design basis accident 

E2 – coating system of all-epoxy two-layered coating system 

E3C – all-epoxy three-component concrete coating system 

E6 - all-epoxy six-layered coating system 

ECCS - emergency core cooling system 

HELB - high-energy line break 

LOCA - loss-of-coolant accident 

NPSH - net positive suction head 

NRC – Nuclear Regulatory Commission 

NSWCCD – Naval Surface Warfare Center, Carderock Division 

PNNL – Pacific Northwest National Laboratory 

PWR – pressurized water reactor 

ZE - inorganic Zinc primer, epoxy topcoat coating system 
xvi 

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1 

1 INTRODUCTION 

1.1 Background

During the recirculation phase of a design basis loss-of-coolant accident (LOCA) at a 

pressurized water reactor (PWR) nuclear power plant, the emergency core cooling system 

(ECCS) and containment spray system (CSS) provide cooling water from the containment sump 

to the reactor core and containment spray header. However, a potential impediment to proper 

cooling water recirculation has been identified. The accumulation of debris generated during a 

LOCA may adversely affect the flow paths necessary for ECCS and CSS recirculation. Generic 

Safety Issue 191 (GSI-191), “Assessment of Debris Accumulation on PWR Sump Performance,” 

was established in 1996 to determine if the transport and accumulation of debris in containment 

following a LOCA would impede or prevent ECCS and CSS operation during recirculation mode 

of operation. 

A technical assessment of GSI-191 was performed by the NRC. The assessment confirmed 

that chips blockage is a generic concern for PWRs, and that plant-specific analysis should be 

performed to address this concern. As the regulatory strategy for resolving GSI-191 was 

developed and interaction with industry on the sump evaluation methodology progressed, the 

NRC identified several additional research tasks necessary for the resolution of GSI-191. 

One of the research tasks is to evaluate the transport characteristics of coating chips in the 

containment pool. A high-energy line break (HELB), including a LOCA, could introduce 

quantities of coating chips into the containment pool. Subsequently, if the ECCS or CSS 

pumps take suction from the containment ECCS sump, the coating chips could be transported 

to the sump and either accumulate--along with other types of debris--on the sump screen or be 

transported through the system. The accumulation of coating chips on the sump screen could 

increase the head loss across the screen. If a sufficient amount of coating chips accumulated 

on the sump screen, the debris bed could reach a critical thickness beyond which the head loss 

across the debris bed could exceed the net positive suction head (NPSH) margin required to 

ensure the successful operation of the ECCS or CSS pumps in recirculation mode. 

Alternatively, coating chips could pass through the sump screen and become ingested into the 

ECCS or CSS suction line such that deleterious downstream effects (e.g., valve clogging, pump 

wear, heat exchanger & reactor fouling, etc.) could occur. 

1.2 Objective

The objective of this work is to parametrically evaluate the transportability of coating chips of 

five different coating systems, under conditions of uniform flow. The effects of chip size, chip 

shape, chip density, chip thickness, and stream velocity on transportability are examined. The 

results of this work are intended to provide guidance for the evaluation of coating chip transport 

under plant-specific conditions. However, evaluators are cautioned to recognize the boundaries 

of this research when applying these observations to their specific plant conditions. 
2 

1.3 Testing Approach

Four salient transport properties in water at ambient temperature were studied: time-to-sink, 

terminal velocity, tumbling velocity and transport velocity. The tests were conducted as follows: 

• The time-to-sink tests consisted of dropping five or ten pieces of coating chips from a 

height of 30.5 cm (12 in) onto a quiescent water surface and recording the time required 

for the chips to break the surface and begin to descend (sink). The number of chips 

sinking initially and the time required for 80 percent and 100 percent of the chips to sink 

was recorded. 

• The terminal velocity tests consisted of placing five to ten coating chips below the 

surface of a quiescent pool and measuring the rate of chip descent. 

• The tumbling velocity tests consisted of placing five coating chips on a flume floor, 

steadily increasing the stream velocity in the flume and recording the stream velocity 

required to initiate movement of the chips along the flume floor. The incipient tumbling 

velocity is the velocity at which the first chip begins to move and the bulk tumbling 

velocity is the velocity at which 80 percent of the chips have moved. 

• The transport tests consisted of releasing a number of coating chips below the surface of 

a flowing stream at a preset velocity and recording the distance the chips traveled prior 

to coming to rest on the floor of the flume or the degree of settling as the chips reached 

the end of the flume. 
3 

2 COATING CHIP CHARACTERISTICS 

2.1 Coatings Tested

Five coating systems of various film thicknesses, formulations and densities were selected for 

testing. These five systems represent the physical characteristics of much of the coating 

systems used in the containment buildings of PWR nuclear power plants. To replicate the 

original installed coating system to the greatest extent practical, each test sample was procured 

from one of the major suppliers of that system. The coating systems selected for testing and 

the rationale for their selection are described below. 

• A non-DBA qualified alkyd coating (ALK), was selected as it represents the lower range 

of densities and film thicknesses found at nuclear power plants. Further, several 

equipment manufacturers used it as a standard coating on equipment installed inside 

containment. 

• An inorganic zinc primer/epoxy system (ZE) was selected as it represents the upper 

range of coating densities and film thickness found at nuclear power plants. Also, ZE 

coating systems were frequently applied to steel structures at nuclear power plants. 

• A two-layered epoxy system (E2) was selected as it represents a medium-density 

coating system frequently applied to steel structures at nuclear power plants. 

• A six-layered epoxy, non-DBA-qualified (due to the number of coats) coating system, 

(E6) was selected as it represents a coating that may exist at some plants where 

coatings maintenance may have resulted in excessive layers of coatings being applied. 

This sample represents a thick, heavy coating system. 

• A qualified multi-layered epoxy system for concrete (E3C) was selected for its rough 

surface structure and frequent use on concrete surfaces inside containment. The 

density is slightly greater than that of the E2 and E6 systems. 

2.2 Coating Chip Size Selection

Coating chip tests were conducted using three distinct chip size ranges; 25 mm to 51 mm (1 in. 

to 2 in.), 3.2 mm to 6.4mm (1/8 in. to 1⁄4 in.), 0.4 mm to 0.8 mm (1/64 in. to 1/32 in.) and one 

sample with a size distribution of 0.4 mm through 51 mm (1/64 in. through 2 in. These size 

ranges are considered to represent the bulk of the coating chips that would be generated during 

a LOCA. Larger coating chips than these size ranges would likely break up, due to their fragile 

nature, while smaller debris is treated as particulate in the sump analysis and, therefore, is 

assumed to transport. 

2.3 Coating Film Preparation

Samples of five coating systems, as described in Paragraph 2.1 and Table 2-1, were prepared 

for use in the experiments described herein. The samples were prepared by the respective 

coating manufacturers, or their subcontractors, and were furnished to Naval Surface Warfare 

Center, Carderock Division, (NSWCCD) through Pacific Northwest National Laboratories. A 

detailed description of the sample preparation and quality assurance records are contained in 

Appendix H. 
4 

2.4 Sample Conditioning

The coating systems tested in this experiment are show in Table 2-1. Samples of each of these 

coatings were received in sheets at NSWCCD. The coatings density and thickness were 

verified and chips were prepared for quiescent settling and transport testing. The preparation 

consisted of creating chips in certain size ranges and shapes, “presoaking” samples for some 

tests, and thermal treatment of epoxy-based chips to evaluate the effect of curing on chip shape 

and density. The processes for generating chips sizes are described in Appendix A. 

Table 2-1 Coatings Systems for Quiescent Settling and Transport Testing 

Code Supplier-Specified 

Nominal Density 

Thickness Description 

ALK 1.15 g/cc (71.79 lb/ft3) 1 coat – 2 mils Low density alkyd topcoat, 

single layer. Unqualified nuclear 

containment coating. 

Ameron, Amercoat 5450 

ZE 5.1 g/cc (318.3 lb/ft3) 

(primer) 

1.75 g/cc (109.24 lb/ft3

) 

(topcoat) 

one coat primer–2.5 mils 

one topcoats – 5 mils 

Inorganic Zinc primer, epoxy 

topcoat. Qualified nuclear 

containment coating. 

Ameron, Dimetcoat 6 primer, 

Amercoat 90 top coats 

E2 1.75 g/cc (109.24 lb/ft3) 2 coats - 5 mils per coat All-epoxy two-layered system 

Qualified nuclear containment 

coating. 

Carboline, Carboguard 890N 

E6 1.75 g/cc (109.24 lb/ft3) 6 coats - 5 mils per coat All-epoxy six-coat system 

Qualified nuclear containment 

coating-Unqualified thickness. 

Carboline, Carboguard 890N 

E3C 1.1 g/cc (68.7 lb/ft3) 

(sealer), 

1.9 g/cc (118.6 lb/ft3) 

(surfacer), 

1.95 g/cc (121.7 lb/ft3

) 

(topcoat) 

1 coat sealer- 1 mil 

1 coat surfacer – 10 mils 

2 topcoats – 4 mils per 

coat 

All-epoxy three-component 

concrete system. Qualified 

nuclear containment coating. 

Keeler & Long, KL4129 epoxy 

sealer, KL6548S epoxy surfacer 

and KLD1 epoxy topcoat 

2.4.1 Presoaking 

To examine the effect of wetting (e. g., by post-LOCA containment spray) on chip settling 

properties, some time-to-sink tests were conducted using presoaked coatings chips. The chips 

were presoaked at 60o

C (140°F) for 20 minutes. To ensure that the chips were not laden with 

excessive moisture, they were placed onto an absorbent sheet immediately before testing to 

remove surface moisture. 
5 

2.4.2 Sizing and Shaping 

The as-manufactured coatings for testing were received in sheets for most of the coating 

systems. Therefore, it was necessary to create appropriately sized samples for testing by 

breaking up the sheets, both by hand and with a commercial blender, and classifying the chips 

into the required size ranges using standard sieves. The classified size ranges are as follows: 

1. 25.4 to 50.8 mm (1 to 2 inches) nominal width, flat and curled chips 

2. 3.2 to 6.4 mm (1/8 to 1/4 inches) nominal width 

3. 0.4 to 0.8 mm (1/64 to 1/32 inches) nominal width 

4. continuous size distribution defined as consisting of chips at least 10% 

(approximate, by weight) and no more than 25% (approximate, by weight) 

smaller than 6.4 mm (1/4 inches) in nominal width. 

Testing of “continuous size distribution” samples is intended to qualitatively investigate possible 

interaction effects between different chip sizes. The brass sieves that were used conform to 

U.S. Bureau of Standards specifications. The sieves used had mesh openings of 50.8 mm (2 

inches), 25.4 mm (1 inch), 6.4 mm (1⁄4 inch), 0.4 mm (0.13 inch, number 6), 0.8 mm (0.03 inch, 

number 20), and 0.40 mm (0.016 inches, number 40). These sieve sizes were the closest 

match to the desired size ranges. The continuous size distributions were created by weighing 

out samples of segregated material to ensure that at least 10% (approximate, by weight) and no 

more than 25% (approximate, by weight) of the chips are smaller than 6.4 mm (1/4 inches) in 

nominal width. 

After segregating the chip sizes in this manner, images of the samples were taken to ensure 

that the size distribution was accurate. Particle sizing software developed in Matlab was used 

to determine the major and minor axis dimensions. Cumulative distribution functions for a 

sample of 100 pieces of each coating and size are shown in Figure 2-1 through Figure 2-5 

below for the major and minor axis dimensions. The figures show the percentage of chips that 

are less than the size indicated on the x-axis. From the figures it can be seen that 100% of the 

chips have an axis dimension less than the upper limit of the size range, and close to 100% of 

the chips have an axis dimension greater than the lower limit of the size range. The plot of the 

major axis length does not go to 100% because only one dimension needs to be less than the 

maximum size to fit through the sieve. Also, note that the continuous size distribution may have 

a bit more than 10% material that is less than 6.4 mm (1/4 inches) in nominal width because the 

distributions were created by weight, not count. Distributions are similar for other samples of 

the same size and coating. 
6 

Figure 2-1 Cumulative Distribution for 25.4 to 50.8 mm (1 to 2 inches) Flat Chips 

Figure 2-2 Cumulative Distribution for 25.4 to 50.8 mm (1 to 2 inches) Curled Chips 

0 0.05 0.1 0.15 0.2 0.25

0

20

40

60

80

100

Minor Axis Length (in)

Percentage

0 0.05 0.1 0.15 0.2 0.25 0

10

20

30

40

50

60

70

80

90

100

Major Axis Length (in)

Percentage

Figure 2-3 Cumulative Distribution for 3.175 to 6.35 mm (1/8 to 1/4 inches) 
7 

0 0.01 0.02 0.03

0

20

40

60

80

100

Minor Axis Length (in)

Percentage

0 0.01 0.02 0.03

0

20

40

60

80

100

Major Axis Length (in)

Percentage

ALK

E2

E3C

E6

ZE

Figure 2-4 Cumulative Distribution for 0.40 to 0.79 mm (1/64 to 1/32 inches) 

0 0.5 1 1.5 2

80

85

90

95

100

Minor Axis Length (in)

Percentage

1/4"

0 0.5 1 1.5 2

80

85

90

95

100

Major Axis Length (in)

Percentage

1/4"

ALK

E2

E3C

E6

ZE

ALK

E2

E3C

E6

ZE

Figure 2-5 Cumulative Distribution for Continuous Size Distribution 

Curling of chips was performed after the chips were appropriately sized. Curled chips were 

created by placing each chip near a heat lamp and then bending the hot chip by hand about one 

axis in a relatively random fashion and allowing the chip to cool. The procedure for creating the 

properly sized and shaped coating chips is contained in Appendix A. 

Some anomalies, as described below, occurred during the creation of the chips. 

• The ZE coating samples arrived in small pieces. Further, they were already curled and 

any attempt to flatten them failed because the chips would break. Therefore, tests with 

flat 25.4mm to 50.8 mm (1 in. to 2 in.) ZE chips were not performed. 

• The 25.4mm to 50.8 mm (1 in. to 2 in.) E3C samples would not curl. Therefore, tests 

with as-received E3C curled chips were not performed. Thermally cured E3C samples 

did retain their curl and, therefore, were tested. 

• The E2 and E6 samples lost their curl (relaxed) when presoaked in 60o

 C (140o F) water. 

The decision was made that it was more important to characterize the effect of shape on 

the transportability than to characterize the effect of presoaking at elevated temperature. 

Further, flat chips were already being tested. Therefore, the E2 and E6 chips were 

presoaked in room temperature 21o

 C (70o F) water. 
8 

2.4.3 Thermal Curing 

During initial handling it was observed that heat caused some of the epoxy-based coatings to 

curl. A possible explanation was that the cross-linking of the epoxy polymer was accelerated by 

the elevated temperature. Therefore, thermal cure was performed on all epoxy-based samples 

(all samples with the exception of ALK) to determine if heating affected paint chip transport 

characteristics. Therefore, in addition to the “as-received” and curled sample conditions, the 

following cured samples were also evaluated: 

• Flat, 25.4 to 50.8 mm (1 to 2 inches), heated to 49o

C (120oF) for 48 hours 

• Curled, 25.4 to 50.8 mm (1 to 2 inches), heated to 49o

C (120oF) for 48 hours 

• Flat, 25.4 to 50.8 mm (1 to 2 inches), heated to 60o

C (150oF) for 14 days 

• Curled, 25.4 to 50.8 mm (1 to 2 inches), heated to 65o

C (150oF) for 14 days 

The 25.4 to 50.8 mm (1 to 2 inches) was chosen as a representative sample because it was 

thought that any changes in characteristics and performance would most readily be seen at 

these sizes. Based on the observations of the behavior of the large chips, a decision would be 

made as to whether to treat the other chip sizes. The cured chips were prepared in a laboratory 

oven under a fume hood on the “as-received” sheets. The desired sizes and shapes were 

created after the curing. The results of size distribution analysis, density measurements, and 

quiescent settling tests were then used to determine if the thermal curing process had any 

significant effect on chip characteristics or performance. These results are discussed in the 

Quiescent Tests section below. An interesting artifact of thermal curing is that it was possible to 

curl the thermally treated E3C debris. Therefore, thermally treated curled E3C chips were 

included in the quiescent test matrix. 

2.5 Coating Density Verification

Coating density was verified by measuring the weight of coating sample necessary to displace 1 

mL of water. Multiple measurements (5 per sample) were made of each coating, and the 

average density and standard deviation are reported in Table 2-2. Also included in this table 

are the manufacturer’s specified densities which generally compare well with the measured 

values. Generally, differences in density, due to accelerated curing, were relatively small (less 

than 4%) and appear to be within the measurement standard deviation. No clear trends were 

evident with continued curing, with the possible exception of the ZE system which became 

slightly less dense with curing. However, all changes were within the measurement standard 

deviation such that no significant curing effects on density were apparent. 
9 

Table 2-2 Sample Density 

Coating 

Average 

Measured 

Density 

Standard 

Deviation 

Manufacturer’s 

Specified 

Density 

 (g/mL, g/cc) (g/mL, g/cc) (g/mL, g/cc) 

ALK (as received) 1.00 0.14 1.15 

ZE (as received) 2.58 0.14 2.54 

E2 (as received) 1.78 0.19 1.75 

E6 (as received) 1.77 0.04 1.75 

E3C (as received) 1.85 0.08 1.86 

ZE (120o/2 days) 2.56 0.07 NA 

E2 (120o/2 days) 1.72 0.08 NA 

E6 (120o/2 days) 1.73 0.11 NA 

E3C (120o/2 days) 1.88 0.07 NA 

ZE (150o/14 days) 2.54 0.02 NA 

E2 (150o/14 days) 1.74 0.04 NA 

E6 (150o/14 days) 1.76 0.10 NA 

E3C (150o/14 days) 1.84 0.09 NA 

2.6 Coating Thickness Verification

For each coating system, the sample thickness was quantified using images of the edges of 

coating chips through a microscope. This was done to verify that the thickness of the chips was 

similar to the manufacturer’s specified thickness. An example of the image for the as-received 

E3C sample is shown in Figure 2-6. Each image was calibrated using a slide with a 2000 μm 

circle. The thicknesses were then calculated using image processing software in Matlab. At 

least 4 samples were measured per coating type. 

t Sample 1 

Sample 2 

Sample 3 

Sample 4 

Sample 5 

Figure 2-6 Microscope Image of E3C 
10 

Table 2-3 shows the average thickness for each coatings system. The E3C thickness was 

measured at the thickest part of the chips, and has the highest standard deviation due to the 

rippled shape of the chips (see Figure 2-6 above). The measured thicknesses are close to the 

manufacturer’s specified thickness. Also, there is not a significant difference between the asreceived coating chips thicknesses and the thermally cured thicknesses. 

Table 2-3 Coating Thicknesses 

Coating Average Total 

Thickness from 

Microscope 

Camera 

Measurements 

Standard 

Deviation 

Manufacturer’s 

Specified Total 

Thickness 

mm (mils) mm (mils) mm (mils) 

ALK (as received) 0.056mm (2.2) 0.015 (0.6) 0.051 (2) 

ZE (as received) 0.180 (7.1) 0.030 (1.2) 0.267 (10.5) 

E2 (as received) 0.218 (8.6) 0.033 (1.3) 0.254 (10) 

E6 (as received) 0.584 (23.0) 0.089 (3.5) 0.762 (30) 

E3C (as received) 0.635 (25.0) 0.185 (7.3) 0.483 (19) 

ZE (120o/2 days) 0.216 (8.5) 0.036 (1.4) NA 

E2 (120o/2 days) 0.211 (8.3) 0.036 (1.4) NA 

E6 (120o/2 days) 0.617 (24.3) 0.114 (4.5) NA 

E3C (120o/2 days) 0.594 (23.4) 0.089 (3.5) NA 

ZE (150o/14 days) 0.198 (7.8) 0.018 (0.7) NA 

E2 (150o/14 days) 0.206 (8.1) 0.041 (1.6) NA 

E6 (150o/14 days) 0.556 (21.9) 0.066 (2.6) NA 

E3C (150o/14 

days) 0.597 (23.5) 0.104 (4.1) NA 
11 

3 QUIESCENT TESTING 

3.1 Test Description

The goals of the quiescent water tests were to determine (1) the time necessary for coating 

chips dropped onto the water surface to break the surface and begin sinking (time-to-sink tests), 

and (2) the rate of descent of submerged coating chips (terminal velocity tests). These tests 

were performed on all five coating systems--including the 25.4 to 50.8 mm (1 to 2 inches) 

thermally treated (cured) coatings systems. 

3.1.1 Time-to-Sink Test 

Time-to-sink tests were conducted by dropping each chip sample from a height of 0.3 m (1 ft). 

The onset of sinking is defined as the time at which a chip breaks the water surface and begins 

to descend. Three metrics for the time-to-sink tests were measured, including initial time-to-sink 

(time required for the first chip to begin sinking), bulk time-to-sink (time necessary for 80% of the 

chips to begin sinking), and final time-to-sink (time necessary for the last chip to begin sinking), 

where all times were measured using a stopwatch. The surface tension of the water in the 

quiescent water test facility was also measured during these tests. Tests were performed using 

approximately 100-200 chips for each sample lot. For the larger sizes (25.4 to 50.8 mm (1 to 2 

inches)), the tests were conducted using 5-10 chips at a time to minimize the interaction 

between chips. This resulted in 10 to 20 tests per sample lot. As the chip size decreased, tests 

were conducted with larger amounts of chips. A detailed procedure for the time-to-sink tests 

can be found in Appendix B. Table 3-1 shows the matrix for the quiescent testing. 

Table 3-1 Quiescent Test Matrix 

Size/Shape Thermal Treatment Coating Initial, Bulk, 

and Final Time 

to Sink

Terminal 

Velocity

25.4 to 50.8 mm 

(1 to 2 in) flat 

None ALK dry & presoaked presoaked 

25.4 to 50.8 mm 

(1 to 2 in) flat 

None 

120o

F/2 days 

150o

F/2 weeks 

E2, E6, E3C dry & presoaked presoaked 

25.4 to 50.8 mm 

(1 to 2 in) curled 

None ZE, E2, E6 dry & presoaked presoaked 

25.4 to 50.8 mm 

(1 to 2 in) curled 

120oF/2 days 

150o

F/2 weeks 

ZE, E2, E6, E3C dry & presoaked presoaked 

3.2 to 6.4 mm 

(1/8 to 1/4 in) 

None ALK, ZE, E2, E6, E3C dry & presoaked presoaked 

0.4 to 0.8 mm 

(1/64 to 1/32 in) 

None ALK, ZE, E2, E6, E3C dry & presoaked presoaked 

Continuous Size 

Distribution 

None ALK, ZE, E2, E6, E3C dry & presoaked presoaked 
12 

3.1.2 Terminal Velocity Test 

Terminal velocity tests were conducted by placing a presoaked chip sample under the water 

surface and measuring the maximum steady-state velocity of the chips as they fell to the bottom 

of the test tank. For the larger chips, 5-10 pieces of each sample were used for each test, while 

for the smaller chips about 1 gram was used. The sample was then presoaked in 140 degree 

Fahrenheit water for 20 minutes. The digital video camera began taking images, and the 

sample was placed under the surface of the water and released. Images were recorded until 

the sample reached the bottom of the tank. The images were saved to a folder identified with 

the sample number and recorded in a test log. This process was repeated until at least 100 

particles were captured in the videos. A detailed procedure for the terminal velocity tests can be 

found in Appendix D. 

3.2 Test Facility

The facility for the quiescent water tests of coating chips was set up in the Specialized Research 

and Advanced Development (SpecRAD) Laboratory in Building 4E, Room 109, at NSWCCD. 

This facility is comprised of a vertical Plexiglas tank with a camera for recording digital images 

from the side of the tank (Figure 3-1). The tank has a 0.3 m (1 ft) by 0.3 m (1 ft) cross-section, 

and is 1.2 m (4 ft) tall. The tank water is free of movement or flow, and was used for both 

terminal velocity and time-to-sink tests. The tensiometer was positioned alongside the tank 

(Figure 3-2). This tensiometer uses the Wilhemy plate method to measure surface tension. In 

this method, a thin plate is lowered to the surface of the liquid and the downward force directed 

to the plate is measured. Surface tension is the force divided by the perimeter of the plate 

(Holmberg, 2002). 
13 

Camera 

view 

Debris 

release 

point 

Bottom 

of tank 

Figure 3-1 Quiescent Test Facility Vertical Tank 

Tensiometer

Figure 3-2 Tensiometer 
14 

3.3 Time-to-Sink Test Results

3.3.1 Large Chips 

Appendix C contains bar charts which summarize the results of the time-to-sink test for 25.4 to 

50.8 mm (1 to 2 inches) chips, both dry and pre-soaked. In each figure of Appendix C, the 

upper charts represent dry samples and the lower charts represent pre-soaked samples. In 

each figure, the left panels show the number of tests out of the total of generally 10 or 20 tests 

for which a certain percentage of chips sank immediately (initial time-to-sink tests). The middle 

panels show the number of tests for which the bulk (80%) of the chips sank in a particular time 

span. The right panels show the number of tests for which all (100%) of the chips sank in a 

particular time span. An entry of “Infinity” indicates the number of incidents in which the sink 

criterion was not met. Figure 3-3 and Figure 3-4 below summarize the results of the initial timeto-sink tests of the large chips. The complete time-to sink results for large chips are contained 

Appendix C. 

Figure 3-3 shows the total percentage of flat 25.4 to 50.8 mm (1 to 2 in) chips that sank initially 

(within 1 second of being dropped onto the surface) for both dry and presoaked samples. No 

25.4 to 50.8 mm (1 to 2 in.) ALK coating chips (dry or presoaked) sank initially in any of the 

time-to-sink tests. Further, the ALK chips remained on the surface indefinitely. Large 

percentages of the E2, E6, and E3C coating samples sank immediately. In general, more 

presoaked chips sank initially than did dry chips. However, the difference was not significant. 

Also, all flat 25.4 to 50.8 mm (1 to 2 inches) chips, regardless of coating type, either sank within 

1 second of being dropped onto the surface, or remained on the surface indefinitely. 

Figure 3-4 shows the percentage of curled 25.4 to 50.8 mm (1 to 2 in) chips that sank 

immediately, totaled over all tests, for both dry and presoaked samples. Almost all of the E6 

chips sank immediately upon hitting the water surface. In contrast, E2 chips had the lowest 

percentage of chips sinking initially. Further, in all tests, some E2 chips remained on the 

surface indefinitely. 

3.3.2 Small Chips 

For the smaller sized chips (3.2 to 6.4 mm (1/8 to 1/4 inches) and 0.4 to 0.8 mm (1/64 to 1/32 

inches) ), the pieces either sank immediately, or remained on the surface indefinitely. As with 

the large ALK chips, none of the small ALK samples sank. Figure 3-5 illustrates that of the 3.2 

to 6.4 mm (1/8 to 1/4 in) chips, E3C had the highest percentage of chips (approximately 90 

percent) that sank initially, while ZE had approximately 50 percent of chips sink initially. Figure 

3-6 illustrates that of the 0.4 to 0.8 mm (1/64 to 1/32 in) chips, E3C had the highest percentage 

of chips to sink initially, while E2 had 20 percent of chips sink initially. Generally, the smaller 

size chips exhibited a greater tendency to remain on the surface indefinitely. 

Overall, the effect of presoaking on time-to-sink does not follow a clear trend. In some cases 

more presoaked chips sank immediately, in some cases fewer, and in some cases the same 

amount. Curling the chips does not have a clear effect either; for E6, a slightly larger amount of 

the curled chips sank immediately, but for E2, fewer of the curled chips sank than the flat chips. 

Over all sizes, the dry E6 and E3C chips have the greatest percentage of chips sinking 

immediately, suggesting that chip weight is a significant factor in determining sink rate. 
15 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

ALK (1.00 g/cc) E2 (1.78 g/cc) E3C (1.85 g/cc) E6 (1.77 g/cc)

Percent of Chips Sinking Initially 

Dry

Presoaked

Figure 3-3 Percent of 25.4 to 50.8 mm (1 to 2 in) Flat Chips Sinking Initially 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

E2 (1.78 g/cc) E6 (1.77 g/cc) ZE (2.54 g/cc)

Percent of Chips Sinking Initially

Dry

Presoaked

Figure 3-4 Percent of 25.4 to 50.8 mm (1 to 2 in) Curled Chips Sinking Initially 
16 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

ALK (1.00 g/cc) E2 (1.78 g/cc) E3C (1.85 g/cc) E6 (1.77 g/cc) ZE (2.54 g/cc)

Percent of Chips Sinking Initially

Dry 

Presoaked

Figure 3-5 Percent of 3.2 to 6.35 mm (1/4 to 1/8 inches) Chips Sinking Initially 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100

ALK (1.00 g/cc) E2 (1.78 g/cc) E3C (1.85 g/cc) E6 (1.77 g/cc) ZE (2.54 g/cc)

Percent of Chips Sinking Initially

Dry 

Presoaked

Figure 3-6 Percent of 0.4 to 0.8 mm (1/32 to 1/64 in) Chips Sinking Initially 
17 

3.4 Terminal Velocity Test Results

Table 3-2 shows the terminal velocity test results, where Vy is the vertical velocity (positive 

down). Figure 3-7 displays the terminal velocity data in graphical form for all of the “asreceived” chips. This figure, illustrates that E3C and E6 have the largest values of terminal 

velocity over all sizes, while ZE is close behind and ALK is clearly lowest. 

From Figure 3-7 it can be seen that the terminal velocity increased with size. However, it is 

more difficult to present an argument on the affect of shape (curl) on terminal velocity as there is 

insufficient data. From the available data for E2 and E6, it can be seen that curling had the 

effect of increasing terminal velocity. However, chip weight combined with chip shape may be a 

greater contributing factor as the curled E6 chips had a 44 % increase in terminal velocity over 

the flat E6 chips and the curled E2 chips had only a 14% increase over the E2 flat chips. The E6 

chips have approximately three times the weight of the E2 chips. A plot of terminal velocity 

versus chip weight per unit area (Figure 3-9) indicates an upward trend with increasing chip size 

and weight per unit area. Further, chip size appears to be the dominant factor. 

The effect of thermal treatment on terminal velocity is illustrated in Figure 3-8. The figure plots 

the terminal velocity test results for 25.4 to 50.8 mm (1 to 2 in) as-received and thermally treated 

chips. Generally, the change in terminal velocity, due to thermal treatment, is subtle and is 

within the standard deviation (see Table 3-2). The one exception may be E6 which exhibited a 

tendency to settle slower with increased thermal-treatment temperature. Because all of these 

coatings are epoxy based (E2 and E6 are Carboguard 890N) and there is no apparent change 

in density due to thermal treatment (see Table 2-2), all the epoxy based chips should exhibit 

similar behavior. Therefore, their terminal velocity versus thermal treatment temperature curves 

should be similar. One explanation for the reduction in terminal velocity for the thermally cured 

E6 is that the treated E6 may be more rigid and, therefore, returns to its original flat condition 

after being manually curled. This would explain why the terminal velocity of the thermally 

treated curled E6 approaches that of the thermally treated flat E6. 

As stated in Paragraph 2.8, the extent to which thermally treated chips were tested was based 

on the observations of the 1” to 2” thermally treated and as-received chips. Because there was 

no observed statistically significant curing effects (as qualified above for E6) on chip density, 

chip thickness, time-to-sink, or terminal velocity, no further testing was performed with thermally 

cured chips. 
18 

Table 3-2 Terminal Velocity Results 

Coating Size Shape

Thermal 

Treatment Vy Vy Std. Dev.

 (ft/s) (mm/s) (ft/s) (mm/s)

ALK 25.4 to 50.8 mm (1 to 2 in) Flat none 0.09 26.41 0.01 2.99 

ALK 3.2 to 6.4 mm (1/8 to 1/4 in) Flat none 0.08 23.01 0.00 0.91 

ALK 0.4 to 0.8 mm (1/64 to 1/32 in) Flat none 0.04 13.70 0.00 0.91 

ZE 25.4 to 50.8 mm (1 to 2 in.) Curled none 0.30 91.84 0.07 20.56 

ZE 25.4 to 50.8 mm (1 to 2 in.) Curled 150o/2 weeks 0.23 70.77 0.05 16.37 

ZE 25.4 to 50.8 mm (1 to 2 in.) Curled 120o/2 days 0.30 91.81 0.09 28.18 

ZE 3.2 to 6.4 mm (1/8 to 1/4 in) Flat none 0.21 64.96 0.02 5.78 

ZE 0.4 to 0.8 mm (1/64 to 1/32 in) Flat none 0.26 78.38 0.06 16.98 

E2 25.4 to 50.8 mm (1 to 2 in.) Flat none 0.22 68.02 0.03 9.26 

E2 25.4 to 50.8 mm (1 to 2 in.) Flat 150o/2 weeks 0.17 50.64 0.03 9.15 

E2 25.4 to 50.8 mm (1 to 2 in.) Flat 120o/2 days 0.18 56.27 0.03 8.75 

E2 25.4 to 50.8 mm (1 to 2 in.) Curled none 0.25 77.45 0.02 6.04 

E2 25.4 to 50.8 mm (1 to 2 in.) Curled 150o/2 weeks 0.25 75.75 0.04 12.83 

E2 25.4 to 50.8 mm (1 to 2 in.) Curled 120o/2 days 0.23 68.73 0.02 6.00 

E2 3.2 to 6.4 mm (1/8 to 1/4 in) Flat none 0.15 45.84 0.02 4.71 

E2 0.4 to 0.8 mm (1/64 to 1/32 in) Flat none 0.13 39.29 0.02 4.68 

E6 25.4 to 50.8 mm (1 to 2 in.) Flat none 0.32 97.76 0.07 20.40 

E6 25.4 to 50.8 mm (1 to 2 in.) Flat 150o/2 weeks 0.27 83.68 0.06 17.86 

E6 25.4 to 50.8 mm (1 to 2 in.) Flat 120o/2 days 0.28 84.25 0.10 31.64 

E6 25.4 to 50.8 mm (1 to 2 in.) Curled none 0.46 140.80 0.08 23.23 

E6 25.4 to 50.8 mm (1 to 2 in.) Curled 150o/2 weeks 0.30 92.62 0.14 42.13 

E6 25.4 to 50.8 mm (1 to 2 in.) Curled 120o/2 days 0.35 105.33 0.08 22.96 

E6 3.2 to 6.4 mm (1/8 to 1/4 in) Flat none 0.24 73.87 0.02 5.82 

E6 0.4 to 0.8 mm (1/64 to 1/32 in) Flat none 0.16 47.42 0.03 8.71 

E3C 25.4 to 50.8 mm (1 to 2 in.) Flat none 0.29 88.68 0.05 13.96 

E3C 25.4 to 50.8 mm (1 to 2 in.) Flat 150o/2 weeks 0.31 95.97 0.10 30.37 

E3C 25.4 to 50.8 mm (1 to 2 in.) Flat 120o/2 days 0.24 73.00 0.09 27.19 

E3C 25.4 to 50.8 mm (1 to 2 in.) Curled 150o/2 weeks 0.28 85.42 0.11 33.16 

E3C 25.4 to 50.8 mm (1 to 2 in.) Curled 120o/2 days 0.27 83.82 0.14 44.06 

E3C 3.2 to 6.4 mm (1/8 to 1/4 in) Flat none 0.24 74.13 0.05 15.43 

E3C 0.4 to 0.8 mm (1/64 to 1/32 in)) Flat none 0.16 50.09 0.03 8.46 
19 

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

ALK (1.15 g/cc) E2 (1.75 g/cc) E3C (1.85 g/cc) E6 (1.75 g/cc) ZE (2.54 g/cc)

Terminal Velocity (Vy, ft/s) 

1/64"-1/32"

1/8"-1/4"

1"-2" Curled

1"-2" Flat

Figure 3-7 Terminal Velocity for “As-Received” Chips

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

As Received 120F Cure 150F Cure

Heat Treat Condition

Terminal Velocity (ft/s)

ZE-Curl

E2 Flat

E2 Curled

E6 flat

E6 Curled

E3C Flat

E3C Curled

Figure 3-8 Terminal Heat-Treat Effects 
20 

E3C 

E6 

E2 

ZE 

ALK 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14

Weight/Unit Area (g/sq cm)

Terminal Velocit

y (ft/sec)

Small

Medium

Large-Flat

Large-Curled

Small

Medium

Large Flat

Large Curled

Figure 3-9 Terminal Velocity Trend With Chip Size and Weight per Unit Area
21 

4 TRANSPORT TESTING 

4.1 Transport Test Facility

The transport test facility was set up in the Circulating Water Channel (CWC) facility at 

NSWCCD (see Figure 4-1). The CWC is capable of developing steady velocities up to 4.6 

m/s (15.2 ft/s). The transport test flume, a 9.1 m (30 ft) long tank with a 0.91 m (3 ft) by 0.91 

m (3 ft) cross-section, was suspended in the CWC such that the depth of water in the flume 

was 0.76 m (30 in.), i.e. the bottom of the flume was 30 inches below the surface. (Figure 

4-2, Figure 4-3). A schematic of the test flume, illustrating the “Front”, “Middle,” and “End” 

sections is shown in Figure 4-4. The “front section” represents the flume section within 0.3 

meter (1 foot) of the chip release point, the “middle section” represents the flume section 

from 0.3 to 4 meters (1 to 13 feet) of the chip release point, and the “end section” represents 

the flume section from 4 to 6.7 meters (13 to 22 feet) of the chip release point. A filter, 

vertically partitioned into three sections (Figure 4-5) and located at the outlet end of the 

flume, collected and classified chips that reached the end of the flume. The chips reaching 

the filter have traveled the entire length of the flume and, therefore, are considered to have 

transported. At the filter, the “top” represents the upper 0.08 m (3 in) of the stream, the 

“middle” is the central 0.6 m (24 in) of the stream, and the “bottom” represents the bottom 

0.08 m (3 in) of the stream. 

The flume was constructed of acrylic to simulate the enamel or polymer coated concrete 

floors of containment buildings. To track chip movement, five underwater cameras were 

placed along the path of travel. The first two cameras were used to track the chip velocity in 

the tank near the release point—one positioned to view the chips from the side and one 

from above. The third and fourth cameras were spaced along the length of the flume to 

track chip movement further downstream, and the fifth camera was positioned to view the 

collection filter. 

Figure 4-1 Circulating Water Channel Facility 
22 

Figure 4-2 Transport Flume in Circulating Water Channel (overhead view) 

Figure 4-3 Transport Flume in Circulating Water Channel (side view) 
23 

3 feet 3 feet 

filter end 

debris release point 

3 feet 

Top view camera 

Side view camera

30 feet

Middle

Front 

End 

Figure 4-4 Schematic of Transport Flume 

Middle (24 in.)

Bottom (3 in.)

Top (3 in.)

Figure 4-5 Filter for Transport Flume 
24 

4.2 Summary of Testing Procedure

The transport tests were performed to determine the transport behavior of coating chips in 

moving water. The transport tests consisted of tumbling velocity tests and steady-state velocity 

tests, with the test matrices shown in Table 4-1 and Table 4-2. 

4.2.1 Tumbling Velocity 

Tumbling velocity is defined as the minimum fluid velocity (averaged over the flume cross 

section) required to tumble (or slide) the chips on the flume floor. To determine this velocity, 

presoaked chip samples were placed on the bottom of the flume under zero-flow conditions. 

For large chips 5-10 chips were used per test, while for small pieces (1/64” to 1/32”) 1 gram of 

chips were used per test. Samples were arranged such that no chips were touching or 

interfering with other chips, and so that the test sample was on the tank floor inside the marked 

area where the sample was viewable by the camera. Once the cameras and acoustic Doppler 

velocimeter (ADV) started recording, fluid velocity was slowly increased until both the incipient 

and bulk tumbling velocity could be determined. The incipient tumbling velocity is defined as the 

fluid velocity required for the first chips to begin tumbling or sliding. Bulk tumbling velocity is 

defined as the fluid velocity required for the bulk of the chips (80%) to begin tumbling or sliding. 

This process was repeated for at least 50 chips of each size, shape, and coating type. A 

detailed procedure for the tumbling velocity is included in Appendix E. 

Table 4-1 Tumbling Velocity Test Matrix 

Size/Shape Coating Tumbling Velocity 

25.4 to 50.8 mm (1 to 2 in) 

Flat 

ALK, E2, E6, E3C incipient, bulk 

25.4 to 50.8 mm (1 to 2 in) 

Curled 

ZE, E2, E6 incipient, bulk 

3.2 to 6.4 mm (1/8 to 1/4 in) ALK, ZE, E2, E6, E3C incipient, bulk 

0.4 to 0.8 mm (1/64 to 1/32 

in) 

ALK, ZE, E2, E6, E3C incipient, bulk 

Distribution ALK, ZE, E2, E6, E3C incipient, bulk 
25 

4.2.2 Steady-State Velocity 

In the steady state velocity tests, dry chip samples were released into a steady-flowing stream 

using a release chamber just below the water surface (about 0.08 m (3 in.)) and the chips’ 

transport properties were observed. For large chips, 5-10 chips were used per test. For small 

chips (1/64” to 1/32”), 1 gram of chips was used per test. The steady-state transport tests were 

performed at two stream velocities—the bulk tumbling velocity and the pre-established threshold 

velocity of 0.06 m (0.2 feet per second). At the end of each steady state transport test, the 

following transport characteristics were recorded: 

1) Fraction of coating chips which transports by floating on the surface of the water (recovered 

from top of filter) 

2) Fraction of coating chips which transports by remaining suspended in the water 

(recovered from middle of filter) 

3) Fraction of coating chips which transports by tumbling or sliding along the bottom of the flume 

(recovered from bottom of filter) 

4) Fraction of coating chips which does not transport to end of flume (comes to rest before 

reaching the end of the flume) 

5) Distribution map of coating chips fragments that came to rest 

6) Velocity history of coating chips 

 

This process was repeated for at least 50 chips of each size, shape, and coating type. A 

detailed procedure for the transport velocity test is included in Appendix F. 

Table 4-2 Steady State Transport Test Matrix 

Size/Shape Coating Transport Velocity 

25.4 to 50.8 mm (1 to 2 in) 

Flat 

ALK, E2, E6, E3C 0.06 m/s (0.2 ft/s), tumbling 

25.4 to 50.8 mm (1 to 2 in) 

Curled 

ZE, E2, E6 0.06 m/s (0.2 ft/s), tumbling 

3.2 to 6.4 mm (1/8 to 1/4 in) ALK, ZE, E2, E6, E3C 0.06 m/s (0.2 ft/s), tumbling 

0.4 to 0.8 mm (1/64 to 1/32 

in) 

ALK, ZE, E2, E6, E3C 0.06 m/s (0.2 ft/s), tumbling 

Distribution ALK, ZE, E2, E6, E3C 0.06 m/s (0.2 ft/s), tumbling 

4.3 Velocity Mapping

A SonTek ADV was used to measure the water velocity during the tumbling velocity testing. At 

the beginning of the experiment, for calibration purposes, measurements were made in 1-inch 

increments throughout the water column over various speeds to determine the average velocity 

over the cross section, as well as the velocity nearest the tank floor. Analysis of this data 

showed that the along-channel, free stream velocity varied by less than five percent throughout 

the water column. 
26 

4.4 Test Results

4.4.1 Tumbling Velocity Test 

Table 4-3 shows the results for the tumbling velocity tests. The bulk tumbling velocity results in 

Table 4-3 are graphically depicted in Figure 4-6. The E6 coating had the highest tumbling 

velocity for the large, flat chips, while ALK chips of this size had the lowest tumbling velocity. 

For the remaining sizes, the ZE chips tend to have the highest tumbling velocities, with ALK 

having the lowest (except for the smallest sizes). 

Table 4-3 Tumbling Velocity Test Results 

Coating Size/Shape Incipient 

Velocity 

Bulk (80%) 

Velocity 

 m/s (ft/s) m/s (ft/s) 

ALK 25.4 to 50.8 mm (1 to 2 in.) 0.049 (0.16) 0.140 (0.46) 

E2 25.4 to 50.8 mm (1 to 2 in.) 0.110 (0.36) 0.259 (0.85) 

E3C 25.4 to 50.8 mm (1 to 2 in.) 0.104 (0.34) 0.308 (1.01) 

E6 25.4 to 50.8 mm (1 to 2 in.) 0.207 (0.68) 0.415 (1.36) 

E2 

25.4 to 50.8 mm (1 to 2 in.) 

curled 0.027 (0.09) 0.082 (0.27) 

E6 

25.4 to 50.8 mm (1 to 2 in.) 

curled 0.012 (0.04) 0.210 (0.69) 

ZE 

25.4 to 50.8 mm (1 to 2 in.) 

curled 0.079 (0.26) 0.131 (0.43) 

ALK 3.2 to 6.4 mm (1/8 to1/4 in) 0.037 (0.12) 0.259 (0.85) 

E2 3.2 to 6.4 mm (1/8 to 1/4 in) 0.174 (0.57) 0.363 (1.19) 

E3C 3.2 to 6.4 mm (1/8 to 1/4 in) 0.207 (0.68) 0.390 (1.28) 

E6 3.2 to 6.4 mm (1/8 to 1/4 in) 0.241 (0.79) 0.351 (1.15) 

ZE 3.2 to 6.4 mm (1/8 to 1/4 in) 0.201 (0.66) 0.408 (1.34) 

ALK 0.4 to 0.8 mm (1/64-1/32 in) 0.037 (0.12) 0.280 (0.92) 

E2 0.4 to 0.8 mm (1/64-1/32 in) 0.201 (0.66) 0.308 (1.01) 

E3C 0.4 to 0.8 mm (1/64-1/32 in) 0.149 (0.49) 0.299 (0.98) 

E6 0.4 to 0.8 mm (1/64-1/32 in) 0.110 (0.36) 0.235 (0.77) 

ZE 0.4 to 0.8 mm (1/64-1/32 in) 0.128 (0.42) 0.415 (1.36) 

ALK Distribution 0.018 (0.06) 0.274 (0.90) 

E2 Distribution 0.107 (0.35) 0.366 (1.20) 

E3C Distribution 0.241 (0.79) 0.433 (1.42) 

E6 Distribution 0.177 (0.58) 0.408 (1.34) 

ZE Distribution 0.040 (0.13) 0.442 (1.45) 
27 

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

ALK (1.15

g/cc)

E2 (1.75 g/cc) E3C (1.85

g/cc)

E6 (1.75 g/cc) ZE (2.54 g/cc)

Bulk Tumbling Velocity

1"-2" flat

1"-2" curled

1/8"-1/4"

1/64"-1/32"

Figure 4-6 Bulk Tumbling Velocity Results 

4.4.2 Steady-State Transport Test 

Table 4-4 shows the chip transport velocities observed in the steady state transport tests, which 

were performed at the previously determined bulk velocity and the 0.06 m/s (0.2 ft/s) velocity. 

For each coating type and water velocity, the average and standard deviation of chip velocity, 

as well as the minimum and maximum chip velocity of all chips tested are listed. In general, the 

recorded average water velocities are slightly higher than the recorded average chip velocities, 

indicating a slip. 

Appendix G contains plots summarizing the degree of transport of each of the coating systems 

and size ranges tested. The plots show the location in the flume where the chips came to rest 

or the section of the filter in which the chips were captured, as applicable. In these plots, the 

“front section” represents the flume section within 0.3 meter (1 foot) of the chip release point, 

the “middle section” represents the flume section from 0.3 to 4 meters (1 to 13 feet) of the chip 

release point, and the “end section” represents the flume section from 4 to 6.7 meters (13 to 22 

feet) of the chip release point. (The end of the flume and the location of the collection filter are 

7.7 meters (22 feet) from the release point). Any chips reaching the filter have traveled the 

entire length of the tank and, therefore, are considered to transport. At the filter, the “top” 

represents the upper 0.08 m (3 in) of the stream, the “middle” is the central 0.6 m (24 in) of the 

stream, and the “bottom” represents the bottom 0.08 m (3 in) of the stream. In the tests 

performed at 0.06 m/s (0.2 ft/s), only a small portion (two to four percent) of the ALK and E2 

chips travel the length of the tank. All of the ZE, E6 and E3C coatings chips settled to the 

bottom of the flume and came to rest at or before the middle section of the tank. In tests 

performed at the coatings’ bulk tumbling velocities, the degree of transport varied significantly. 

Chips with the higher bulk tumbling velocities transported the furthest. Large flat chips, large 

curled chips and mid-sized chips (except ALK) that transported were recovered in the bottom 

section of the filter. The bulk of the mid-sized ALK was recovered in the middle and top 
28 

sections of the filter (71 percent and 21 percent, respectively). Small chips of ALK, E2 and ZE 

transported readily (over 60 percent) and were recovered, primarily, in the mid-section of the 

filter. 

Table 4-4 Transport Test Results (Metric Units) 

 Water Velocity Chip Velocity (m/s) 

Coating Size/Shape (m/s) Average St. Dev. Min. Max.

E2 25.4 to 50.8 mm 0.26* 0.192 0.012 0.180 0.207

 25.4 to 50.8 mm 0.06 0.043 0.015 0.015 0.070

 25.4 to 50.8 mm, curled 0.08* 0.058 0.012 0.040 0.079

 25.4 to 50.8 mm, curled 0.06 0.037 0.015 0.012 0.067

 3.2 to 6.4 mm 0.36* 0.241 0.012 0.223 0.259

 3.2 to 6.4 mm 0.06 0.040 0.012 0.018 0.067

 0.4 to 0.8 mm 0.31* 0.250 0.009 0.226 0.250

 0.4 to 0.8 mm 0.06 0.040 0.006 0.030 0.055

 Distribution 0.37* 0.326 0.009 0.317 0.335

 Distribution 0.06 0.040 0.012 0.018 0.061

E6 25.4 to 50.8 mm 0.41* 0.366 0.006 0.360 0.372

 25.4 to 50.8 mm 0.06 0.040 0.009 0.024 0.055

 25.4 to 50.8 mm, curled 0.21* 0.152 0.018 0.125 0.177

 25.4 to 50.8 mm, curled 0.06 0.049 0.021 0.021 0.085

 3.2 to 6.4 mm 0.35* 0.320 0.012 0.308 0.332

 3.2 to 6.4 mm 0.06 0.034 0.012 0.012 0.058

 0.4 to 0.8 mm 0.23* 0.201 0.000 0.189 0.213

 0.4 to 0.8 mm 0.06 0.046 0.006 0.034 0.058

 Distribution 0.41* 0.341 0.009 0.332 0.354

 Distribution 0.06 0.030 0.015 0.009 0.061

E3C 25.4 to 50.8 mm 0.31* 0.290 0.012 0.277 0.305

 25.4 to 50.8 mm 0.06 0.037 0.015 0.006 0.058

 3.2 to 6.4 mm 0.39* 0.268 0.012 0.253 0.287

 3.2 to 6.4 mm 0.06 0.034 0.012 0.015 0.058

 0.4 to 0.8 mm 0.30* 0.262 0.012 0.250 0.277

 0.4 to 0.8 mm 0.06 0.046 0.006 0.034 0.061

 Distribution 0.43* 0.305 0.009 0.293 0.314

 Distribution 0.20 0.027 0.009 0.012 0.046

ZE 25.4 to 50.8 mm, curled 0.13* 0.116 0.018 0.088 0.146

 25.4 to 50.8 mm, curled 0.06 0.049 0.021 0.012 0.088

 3.2 to 6.4 mm 0.41* 0.296 0.012 0.280 0.308

 3.2 to 6.4 mm 0.06 0.040 0.015 0.009 0.070

 0.4 to 0.8 mm 0.41* 0.351 0.006 0.347 0.357

 0.4 to 0.8 mm 0.06 0.043 0.009 0.030 0.055

 Distribution 0.44* 0.326 0.009 0.317 0.335

 Distribution 0.06 0.037 0.015 0.012 0.067

ALK 25.4 to 50.8 mm 0.14* 0.119 0.006 0.107 0.128

 25.4 to 50.8 mm 0.06 0.034 0.009 0.018 0.049

 3.2 to 6.4 mm 0.26* 0.256 0.009 0.244 0.265

 3.2 to 6.4 mm 0.06 0.052 0.009 0.040 0.064

 0.4 to 0.8 mm 0.28* 0.253 0.006 0.244 0.262

 0.4 to 0.8 mm 0.06 0.046 0.009 0.030 0.064

 Distribution 0.27* 0.259 0.006 0.250 0.271

 Distribution 0.06 0.034 0.009 0.021 0.049

*represents the bulk tumbling velocity 
29 

Table 4-5 Transport Test Results (English Units) 

 Water Velocity Chip Velocity (ft/s) 

Coating Size/Shape (ft/s) Average St. Dev. Min. Max. 

E2 1 to 2 in 0.85* 0.63 0.04 0.59 0.68 

 1 to 2 in 0.20 0.14 0.05 0.05 0.23 

 1 to 2 in, curled 0.27* 0.19 0.04 0.13 0.26 

 1 to 2 in, curled 0.20 0.12 0.05 0.04 0.22 

 1/8 to 1⁄4 in 1.19* 0.79 0.04 0.73 0.85 

 1/8 to 1⁄4 in 0.20 0.13 0.04 0.06 0.22 

 1/64 to 1/32 in 1.01* 0.82 0.03 0.74 0.82 

 1/64 to 1/32 in 0.20 0.13 0.02 0.10 0.18 

 Distribution 1.20* 1.07 0.03 1.04 1.10 

 Distribution 0.20 0.13 0.04 0.06 0.20 

E6 1 to 2 in 1.36* 1.20 0.02 1.18 1.22 

 1 to 2 in 0.20 0.13 0.03 0.08 0.18 

 1 to 2 in, curled 0.69* 0.50 0.06 0.41 0.58 

 1 to 2 in, curled 0.20 0.16 0.07 0.07 0.28 

 1/8 to 1⁄4 in 1.15* 1.05 0.04 1.01 1.09 

 1/8 to 1⁄4 in 0.20 0.11 0.04 0.04 0.19 

 1/64 to 1/32 in 0.77* 0.66 0.00 0.62 0.70 

 1/64 to 1/32 in 0.20 0.15 0.02 0.11 0.19 

 Distribution 1.34* 1.12 0.03 1.09 1.16 

 Distribution 0.20 0.10 0.05 0.03 0.20 

E3C 1 to 2 in 1.01* 0.95 0.04 0.91 1.00 

 1 to 2 in 0.20 0.12 0.05 0.02 0.19 

 1/8 to 1⁄4 in 1.28* 0.88 0.04 0.83 0.94 

 1/8 to 1⁄4 in 0.20 0.11 0.04 0.05 0.19 

 1/64 to 1/32 in 0.98* 0.86 0.04 0.82 0.91 

 1/64 to 1/32 in 0.20 0.15 0.02 0.11 0.20 

 Distribution 1.42* 1.00 0.03 0.96 1.03 

 Distribution 0.20 0.09 0.03 0.04 0.15 

ZE 1 to 2 in, curled 0.43* 0.38 0.06 0.29 0.48 

 1 to 2 in, curled 0.20 0.16 0.07 0.04 0.29 

 1/8 to 1⁄4 in 1.34* 0.97 0.04 0.92 1.01 

 1/8 to 1⁄4 in 0.20 0.13 0.05 0.03 0.23 

 1/64 to 1/32 in 1.36* 1.15 0.02 1.14 1.17 

 1/64 to 1/32 in 0.20 0.14 0.03 0.10 0.18 

 Distribution 1.45* 1.07 0.03 1.04 1.10 

 Distribution 0.20 0.12 0.05 0.04 0.22 

ALK 1 to 2 in 0.46* 0.39 0.02 0.35 0.42 

 1 to 2 in 0.20 0.11 0.03 0.06 0.16 

 1/8 to 1⁄4 in 0.85* 0.84 0.03 0.80 0.87 

 1/8 to 1⁄4 in 0.20 0.17 0.03 0.13 0.21 

 1/64 to 1/32 in 0.92* 0.83 0.02 0.80 0.86 

 1/64 to 1/32 in 0.20 0.15 0.03 0.10 0.21 

 Distribution 0.90* 0.85 0.02 0.82 0.89 

 Distribution 0.20 0.11 0.03 0.07 0.16 

*represents the bulk tumbling velocity
30 

Page Intentionally Blank
31 

5 CONCLUSIONS 

The quiescent tests demonstrated that (1) light-weight coating chips, specifically alkyd chips, 

dropped onto the water surface tended to remain on the surface indefinitely, (2) a large percent 

of the heavy coating chips (six-coat epoxy and epoxy system for concrete) sank immediately, 

and (3) a lower percent of the medium-weight coating chips (two-coat epoxies, zinc/epoxy 

systems) sank initially. These results imply that a large percentage of low density coating chips 

and a small percentage of higher density coating chips that ended up on the pool surface could 

transport with the current generated by the ECCS/CSS recirculation pumps. 

The tumbling velocity tests demonstrated that the highest bulk tumbling velocity was associated 

with the heaviest flat coating chips, approximately 0.43 m/s (1.4 ft/s). The curled and light chips 

had the lowest tumbling velocities with the bulk of the chips tumbling at 0.08 m/s (0.27 ft/s) and 

0.14 m/s (0.46 ft/s) for curled two-coat epoxy and one-coat alkyd coating systems, respectively. 

In the steady-state velocity test, at a uniform water velocity of 0.06 m/s (0.2 ft/s), all but the 

lightest chips came to rest at the bottom of the flume within a short distance of the release point. 

Only a small percent of the medium-sized alkyd chips transported to the end of the test flume by 

floating on the surface. These results imply that coating chips possessing physical 

characteristics similar to the coatings tested herein will likely not transport significant distances 

at uniform stream velocities of 0.06 m/s (0.2 ft/s) or less. 
32 

Page Intentionally Blank
33 

6 REFERENCES 

Holmberg, Krister. Handbook of Applied Surface and Colloid Chemistry, Volumes 1-2 , 2002 

John Wiley & Sons. 
34 

Page Intentionally Blank
A-1 

APPENDIX A: PROCEDURE FOR SIZING COATING CHIPS 

E2, E3C, E6, and ZE Sample 

Method for size 1” – 2” flat 

1) Place sheet(s) of material in bag 

2) Break up by hand into small pieces (approximately 1 to 2 inches) 

3) Use 1” and 2” sieve to filter out chips larger than 2” and smaller than 1” 

4) Add sieved material to sample container. 

5) Repeat steps 1 to 4 to obtain sufficient sample population (~200-400 pieces) 

6) Weigh sample and record in table. 

7) Place sample in container for storage until test 

8) Label container with sample number from chart 

Note: ZE samples arrived in a curled shape, and could not be flattened, so no flat ZE chips were 

created. 

Method for size 1” – 2” curled 

1) Place sheet(s) of material in bag 

2) Break up by hand into small pieces (approximately 1 to 2 inches) 

3) Use 1” and 2” sieve to filter out chips larger than 2” and smaller than 1” 

4) Repeat steps 1 to 4 to obtain sufficient sample population (~200-400 pieces) 

5) Curl each piece by holding next to the heat lamp and bending piece by hand in a 

relatively random fashion. 

6) Add sieved material to sample container. 

7) Weigh sample and record weight in table. 

8) Place sample in container for storage until test. 

9) Label container with sample number from chart. 

Note: As-received E3C did not hold curl; therefore, no curled as-received E3C chips were 

created. 

Method for size 1/8” – 1/4” 

1) Place sheet(s) of material in bag 

2) Break up by hand into small pieces (approximately 1 to 2 inches). 

3) Crumble pieces in bag by hand to smallest size possible. 

4) Use entire set of sieves to filter chips into size ranges. 

5) Add sieved material to sample containers. 

6) Repeat steps 1 to 5 to obtain desired amount of sample. 

7) Weigh sample(s) and record in table. 

8) Place sample in container for storage until test 

9) Label container with sample number from chart. 
A-2 

Method for size range 1/64” – 1/32” 

1) Place sheet in bag 

2) Break up by hand into large pieces 

3) Place large pieces in blender 

4) Place in blender and blend for 15 seconds 

5) Use entire set of sieves to filter chips into size ranges. 

6) Add sieved material to sample containers. 

7) Weigh sample(s) and record in table. 

8) Place sample in container for storage until test 

9) Label container with sample number from chart. 

ALK Sample 

Method for size 1” – 2” flat 

1) Cut a large piece of paint from the sample sheets. 

2) Peel large piece from the plastic sheet. 

3) Break peeled sheet by hand into small pieces (approximately 1 to 2 inches) 

4) Use 1” and 2” sieve to filter out chips larger than 2” and smaller than 1” 

5) Add sieved material to sample container. 

6) Repeat steps 1 to 5 to obtain sufficient sample population (~200 pieces) 

7) Weigh sample and record in table. 

8) Place sample in container for storage until test 

9) Label container with sample number from chart 

Method for size 1” – 2” curled 

Curled chips could not be manufactured with the provided sample. Material was not sufficiently 

rigid to hold curl. 

Method for size 1/8” – 1/4” 

1) Cut a large piece of paint from the sample sheets. 

2) Peel large piece from the plastic sheet. 

3) Break peeled sheet by hand into small pieces (approximately 1 to 2 inches) 

4) Place pieces in blender and blend for approximately 0.5 seconds. 

5) Use entire set of sieves to filter particles into size ranges. 

6) Add sieved material to sample containers. 

7) Repeat steps 1 to 6 to obtain desired amount of sample. 

8) Weigh sample(s) and record in table. 

9) Place sample in container for storage until test 

10) Label container with sample number from chart. 
A-3 

Method for size range 1/64” – 1/32” 

1) Cut a large piece of paint from the sample sheets. 

2) Peel large piece from the plastic sheet. 

3) Break peeled sheet by hand into small pieces (approximately 1 to 2 inches) 

4) Place pieces in blender and blend for approximately 3 seconds. 

5) Use entire set of sieves to filter chips into size ranges. 

6) Add sieved material to sample containers. 

7) Repeat steps 1 to 6 to obtain desired amount of sample. 

8) Weigh sample(s) and record in table. 

9) Place sample in container for storage until test 

10) Label container with sample number from chart. 
A-4 

Page Intentionally Blank
B-1 

APPENDIX B: PROCEDURE FOR TIME-TO-SINK TESTS 

Test Procedure: Time-to-Sink test, dry chips 

1) Count 20 pieces from sample and weigh for large pieces. For small pieces (1/64” to 

1/32”) weigh out 1 gram of particles. 

2) Take digital picture of sample spread on light or dark background, depending on paint 

chip color in order to perform size characterization. Record picture number and test 

number in test log. 

3) Place test sample in release mechanism. 

4) Record water surface tension. 

5) Release sample and start timer. 

6) Record Initial Time-to-Sink (first pieces sinking) in test log. 

7) Record Bulk (80%) Time-to-Sink (average time for bulk of chips) in test log. 

8) Record Final Time to Sink in test log. 

9) Repeat 10 times for each paint sample. 

Test Procedure: Time-to-Sink test: Presoaked Paint Chips 

 

1) Count 10-20 pieces from sample and weigh for large pieces. For small pieces (1/64” 

to 1/32”) weigh out 1 gram of particles. 

2) Take digital picture of sample spread on light or dark background, depending on paint 

chip color in order to perform size characterization. Record picture number and test 

number in test log. 

3) Presoak chips in 140 degree Fahrenheit water for 20 minutes. 

4) Remove excess water from presoaked sample by separating chips and placing on an 

absorbent sheet. 

5) Place test sample in release mechanism. 

6) Record water surface tension. 

7) Release sample and start timer. 

8) Record Initial Time-to-Sink (first pieces sinking) in test log. 

9) Record Bulk (80%) Time-to-Sink in test log. 

10) Record Final Time-to-Sink in test log. 

11) Repeat 10 times for each paint sample. 
B-2 

Page Intentionally Blank 
C-1 

APPENDIX C: RESULTS FOR TIME-TO-SINK TEST 

Figure C-1 ZE, 1"-2", Curled, as Received, Time-To-Sink Test Results 

Note: Each row of each figure in Appendix C provides results for a set of “time-to-sink” tests for 

the sample listed on the graph. For example, in the “Percentage of Chips Sinking Initially Test” 

(upper left panel of Figure C-1) , out of 20 tests for ZE, 1”-2”, curled, as-received, dry chips, 

20% of the chips sank initially in 2 of the tests, 40% sank initially in 3 of the tests, 60% sank in 7 

of the tests, 80% sank in 5 of the tests, and 100% sank in 3 of the tests. 

In the graph that describes the bulk time for the chips to sink (entitled “Time for 80% of Chips to 

Sink”), the number of occurrences is on the y-axis, while the time for the chips to sink (in 

seconds) is on the x-axis. The top middle panel shows that in 13 of the tests, 80% of the chips 

sank between 0-5 seconds. In 7 tests, most of the chips remained on the surface, never having 

80% of the total sink. The graph entitled “Time for All Chips to Sink” shows the same 

information for 100% of the chips. 
C-2 

Figure C-2 ZE, 1"-2", Curled, Thermal Cured at 120oF for 2 Days, Time-To-Sink Test Results 
C-3 

Figure C-3 ZE, 1"-2", Curled, Thermal Cured at 150oF for 2 Weeks, Time-To-Sink Test Results 
C-4 

Figure C-4 E2, 1"-2", Flat, as Received, Time-To-Sink Test Results 
C-5 

Figure C-5 E2, 1"-2", Flat, Thermally Cured at 120o F for 2 Days, Time-To-Sink Test Results 
C-6 

Figure C-6 E2, 1"-2", Flat, Thermally Cured at 150o F for 2 Weeks, Time-To-Sink Test Results 
C-7 

Figure C-7 E2, 1"-2", Curled, as Received, Time-To-Sink Test Results 
C-8 

Figure C-8 E2, 1"-2", Curled, Thermally Cured at 120o F for 2 Days, Time-To-Sink Test Results 
C-9 

Figure C-9 E2, 1"-2", Curled, Thermally Cured at 150o F for 2 Weeks, Time-To-Sink Test Results 
C-10 

Figure C-10 E6, 1"-2", Flat, as Received, Time-To-Sink Test Results 
C-11 

Figure C-11 E6, 1"-2", Flat, Thermally Cured at 120o F for 2 Days, Time-To-Sink Test Results 
C-12 

Figure C-12 E6, 1"-2", Flat, Thermally Cured at 150o F for 2 Weeks, Time-To-Sink Test Results 
C-13 

Figure C-13 E6, 1"-2", Curled, as Received, Time-To-Sink Test Results 
C-14 

Figure C-14 E6, 1"-2", Curled, Thermally Cured at 150o F for 2 Weeks, Time-To-Sink Test Results 
C-15 

Figure C-15 E3C, 1"-2", Flat, as Received, Time-To-Sink Test Results 
C-16 

Figure C-16 E3C, 1"-2", Flat, Thermally Cured at 120o F for 2 Days, Time-To-Sink Test Results 
C-17 

Figure C-17 E3C, 1"-2", Flat, Thermally Cured at 150o F for 2 Weeks, Time-To-Sink Test Results 
C-18 

Figure C-18 E3C, 1"-2", Curled, Thermally Cured at 120o F for 2 Days, Time-To-Sink Test Results 
C-19 

Figure C-19 E3C, 1"-2", Curled, Thermally Cured at 150o F for 2 Weeks, Time-To-Sink Test Results 
C-20 

Page Intentionally Blank 
D-1 

APPENDIX D: PROCEDURE FOR TERMINAL VELOCITY TESTS 

1) Count 5-10 pieces from sample for larger pieces. Weigh sample. For small pieces 

(1/64” to 1/32”) weigh out 1 gram of chips. 

2) Take digital picture of sample spread on light or dark background, depending on paint 

chip color in order to perform size characterization. Record picture number and test 

number on test sheet. 

3) Presoak particles in 140 degree Fahrenheit water for 20 minutes. 

4) Record water surface tension. 

5) Place test sample under the surface of the water. 

6) Release sample. 

7) Record video images of sinking paint chips. 

8) Save images to folder identifying sample number and record in test log. 

9) Repeat until at least 100 chips are shown in videos. 
D-2 

Page Intentionally Blank
E-1 

APPENDIX E: PROCEDURE FOR TUMBLING VELOCITY TESTS 

1) Count 5-10 pieces from sample for larger chips. Weigh sample. For small pieces (1/64” 

to 1/32”) weigh out 1 gram of particles. 

2) Take digital picture of sample spread on light or dark background, depending on paint 

chip color in order to perform size characterization. Record picture number and test 

number on test sheet. 

3) Presoak particles in 140 degree Fahrenheit water for 20 minutes. 

4) Place test sample on the tank floor inside marked area where the sample is viewable by 

the camera. 

5) Start recording video and acoustic Dopler velocimeter (ADV) velocity. 

6) Slowly increase flume velocity until all chip have been brought into suspension. 

7) Save images to folder identifying sample number and record in test log. 

8) Repeat this process for at least 50 particles. 
E-2 

Page Intentionally Blank
F-1 

APPENDIX F: PROCEDURE FOR TRANSPORT TEST 

1) Count 5-10 pieces from sample for larger pieces. Weigh sample. For small pieces 

(1/64” to 1/32”) weigh out 1 gram of chips. 

2) Take digital picture of sample spread on light or dark background, depending on paint 

chip color in order to perform size characterization. Record picture number and test 

number on test sheet. 

3) Set flume velocity to desired test velocity. 

4) Place chips into release chamber and close door. 

5) Insert release chamber into tank. 

6) Start recording video and acoustic Doppler velocimeter (ADV) velocity. 

7) Release chips into tank. 

8) Continue recording images and data until all chips stops moving. 

9) Record the number of chips pieces in each section of the tank and filter. 

10) Save images to folder identifying sample number and record in test log. 

11) Repeat this process for at least 50 chips. 
F-2 

Page Intentionally Blank
G-1 

APPENDIX G: RESULTS FOR STEADY-STATE TRANSPORT TEST 

Appendix G contains plots summarizing the degree of transport of each of the coating systems 

and size ranges tested. The plots show the location in the flume where the chips came to rest 

or the section of the filter on which the chips were captured, as applicable. In these plots, the 

“front section” represents the flume section within 0.3 meter (1 foot) of the chip release point, 

the “middle section” represents the flume section from 0.3 to 4 meters (1 to 13 feet) of the chip 

release point, and the “end section” represents the flume section from 4 to 6.7 meters (13 to 22 

feet) of the chip release point. (The end of the flume and the location of the collection filter are 

7.7 meters (22 feet from the release point)). Any chip reaching the filter has traveled the entire 

length of the tank and, therefore, are considered to transport. At the filter, the “top” represents 

the upper 0.08 m (3 in) of the stream, the “middle” is the central 0.6 m (24 in) of the stream, and 

the “bottom” represents the bottom 0.08 m (3 in) of the stream. 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Top of Filter 0% 0% 0%

Middle of Filter 0% 0% 0%

Bottom of Filter 0% 48% 13%

End Section 10% 12% 5%

Middle Section 90% 40% 82%

Front Section 0% 0% 0%

E2 (0.3 ft/s) E6 (0.7 ft/s) ZE (0.4 ft/s)

c

Figure G-1 Transport Test Results for Curled, 1”-2” Chips, at the Bulk Tumbling Velocity 
G-2 

Figure G-2 Transport Test Results for Flat, 1”-2” Chips, at the Bulk Tumbling Velocity 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Top of Filter 15% 0.0% 0% 0%

Middle of Filter 0% 0.0% 0% 0%

Bottom of Filter 77% 72.5% 18% 24%

End Section 6% 12.5% 18% 45%

Middle Section 2% 15.0% 64% 31%

Front Section 0% 0.0% 0% 0%

ALK (0.5 ft/s) E2 (0.9 ft/s) E3C (0.9 ft/s) E6 (1.4 ft/s)
G-3 

Figure G-3 Transport Test Results for 1/8”-1/4” Chips, at the Bulk Tumbling Velocity 

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Top of Filter 21% 2% 5.0% 0.0% 0.0%

Middle of Filter 71% 2% 8.0% 0.0% 0.0%

Bottom of Filter 8% 44% 54.0% 11.0% 58.5%

End Section 0.0% 49% 15.0% 23.0% 30.2%

Middle Section 0.0% 3% 18.0% 66.0% 11.3%

Front Section 0.0% 0.0% 0.0% 0.0% 0.0%

ALK (0.9 ft/s) E2 (1.2 ft/s) E3C (1.3 ft/s) E6 (1.2 ft/s) ZE (1.4 ft/s)
G-4 

Figure G-4 Transport Test Results for 1/64”-1/32” Chips, at the Bulk Tumbling Velocity 

 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Top of Filter 6% 0% 3% 0% 0%

Middle of Filter 93% 62% 20% 9% 54%

Bottom of Filter 0% 5% 12% 11% 9%

End Section 1% 27% 25% 26% 29%

Middle Section 0% 6% 40% 54% 8%

Front Section 0% 0% 0% 0% 0%

ALK (0.9 ft/s) E2 (1 ft/s) E3C (1 ft/s) E6 (0.8 ft/s) ZE (1.4 ft/s)
G-5 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Top of Filter 0% 0% 0%

Middle of Filter 0% 0% 0%

Bottom of Filter 0% 0% 0%

End Section 4% 0% 0%

Middle Section 80% 18% 100%

Front Section 16% 82% 0%

E2 E6 ZE

Figure G-5 Transport Test Results for Curled, 1”-2” Chips, at 0.2 ft/s 
G-6 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Top of Filter 0% 0% 0% 0%

Middle of Filter 0% 0% 0% 0%

Bottom of Filter 0% 0% 0% 0%

End Section 2% 0% 0% 0%

Middle Section 96% 94% 86% 96%

Front Section 2% 6% 14% 4%

ALK E2 E3C E6

Figure G-6 Transport Test Results for Flat, 1”-2” Chips, at 0.2 ft/s 
G-7 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Top of Filter 3% 0% 0% 0% 0%

Middle of Filter 0% 0% 0% 0% 0%

Bottom of Filter 0% 0% 0% 0% 0%

End Section 0% 0% 0% 0% 0%

Middle Section 97% 100% 0% 0% 100%

Front Section 0% 0% 100% 100% 0%

ALK E2 E3C E6 ZE

Figure G-7 Transport Test Results for 1/8”-1/4” Chips, at 0.2 ft/s 
G-8 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Top of Filter 0% 0% 0% 0% 0%

Middle of Filter 0% 0% 0% 0% 0%

Bottom of Filter 0% 0% 0% 0% 0%

End Section 0% 0% 0% 0% 0%

Middle Section 100% 98% 100% 100% 100%

Front Section 0% 2% 0% 0% 0%

ALK E2 E3C E6 ZE

Figure G-8 Transport Test Results for 1/64”-1/32” Chips, at 0.2 ft/s 
H-1 

APPENDIX H: COATING SYSTEMS SAMPLE PREPARATION 

Samples of five containment coatings systems were prepared for transport testing. Nuclear 

Regulatory Commission (NRC) staff initiated contact with coatings manufactures and downselected to the five systems from three manufactures as shown in Table H-1. These included a 

single coat alkyd, four epoxy systems, and a inorganic zinc/epoxy system. Three of these were 

Nuclear Service Level I coatings qualified for in-containment use. The coating systems are 

listed in Table H-1. 

Table H-1. Coatings Systems for Manufacture – Transport Tests 

System 

Code 

Nuclear 

Service 

Level 1 

 

ALK no Manufacturer Ameron 

 Coating type Alkyd topcoat 

 Components Amercoat 5450 (one coat) 

 

ZE yes Manufacturer Ameron 

 Coating type Inorganic zinc primer/epoxy topcoat 

 Components Dimetcote 6 (one coat) followed by 

Amercoat 90 (two coats) 

 

E2 yes Manufacturer Carboline 

 Coating type Two-layered all epoxy system 

 Components Carboguard 890N (two coats) 

 

E6 no Manufacturer Carboline 

 Coating type Six-layered all epoxy system 

 Components Carboguard 890N (six coats) 

 

E3C yes Manufacturer Keeler & Long 

 Coating type Multi-layered epoxy system for concrete 

 Components KL4129 epoxy sealer (one coat) followed by 

KL6548S epoxy surfacer (one coat) followed by 

KLD1 epoxy topcoat (two coats) 

Three original requirements were set for the samples: 

• Quantity required for each coating system was 125 ft2

• Size distribution requirement for each coatings system was that >25% of chips must be 

> 1-inch average width. 

• Preparation of the samples should be as close as possible to that used for the original 

application. 

Transport testing required coatings samples that were free from the underlying substrate. In 

typical applications, this substrate would be either concrete or steel. Since the coating is not 

easily removed from these materials, the approach recommended by all three manufacturers 
H-2 

was to apply the coating onto plastic sheets. After drying/curing, the coating layer could be 

removed from the plastic sheets for further sample preparation. This recommended practice 

was followed by all three manufacturers. The samples were shipped to the test facility adhered 

to the plastic sheets, rolled, folded up, or cut into smaller sheets to fit in a box for shipping. 

Removal of the coatings from the sheeting was accomplished by the testing laboratory. 

Other than the difference in substrate and a modified procedure for one sample that is 

described below, application procedures followed the recommended guidelines for each coating 

or coatings system. Quality assurance documentation provided with each sample is described 

below. 

For Nuclear Service Level 1 Coating System Samples (sample codes ZE, E2 and E3C): 

1) Certification that the coating system was applied according to application procedures for 

the Nuclear Service Level 1 coating system, plus a copy of that procedure and sample 

preparation sheets completed during the application. 

2) Material certifications for components in the coating system. 

For non-Nuclear Service Level 1 Coating System Samples (sample codes ALK and E6): 

1) Application should follow good industrial practice for the coating system. Provide 

application procedure used and sample preparation sheets completed during the 

application. 

2) Coatings Shelf-Life Certification. 

A modified process was used with Ameron’s zinc primer/epoxy topcoat sample (system code 

ZE). For this sample, it was found that the inorganic zinc primer would become brittle and crack 

if dried for the recommended time. Subsequent application of the epoxy coat could not be 

made without spalling off much of the cracked primer. To produce a uniformly layered sample, 

the normal procedure was modified to allow a shortened drying time for the primer. Also, rather 

than applying two coats of epoxy (Amercoat 90) a thicker single coat was applied. This also 

helped eliminate the cracking and spalling experienced when applying a second epoxy coat. 

The dry film thickness (DFT) of the thicker single coat was 5 mils (0.005 inch) as compared with 

the 8 mil recommended thickness of the two epoxy layers. Ameron has successfully tested this 

coating system in design basis accident (DBA) tests when the epoxy DFT is 5 mils. 

 

The Ameron and Keeler & Long samples were prepared in the respective manufacturers’ 

facilities. The Carboline samples were prepared by a subcontractor, Corrosion Control 

Consultants & Labs CCC&L, in accordance with Carboline application procedures and 

Carboline furnished coating material.