Draft 

ADVISORY BOARD ON 

RADIATION AND WORKER HEALTH 

National Institute for Occupational Safety and Health 

SUPPLEMENTARY COMMENTS ON REVISION 01 OF 

BATTELLE-TBD-6000 

Contract No. 200-2009-28555 

Prepared by 

William C. Thurber 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, VA 22182 

May 2013 

Disclaimer 

This document is made available in accordance with the unanimous desire of the Advisory Board on 

Radiation and Worker Health (ABRWH) to maintain all possible openness in its deliberations. However, 

the ABRWH and its contractor, SC&A, caution the reader that at the time of its release, this report is predecisional and has not been reviewed by the Board for factual accuracy or applicability within the 

requirements of 42CFR82. This implies that once reviewed by the ABRWH, the Board’s position may 

differ from the report’s conclusions. Thus, the reader should be cautioned that this report is for 

information only and that premature interpretations regarding its conclusions are unwarranted.
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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S. COHEN & ASSOCIATES: 

Document No.: Supplementary 

Comments on TBD-6000 Rev. 01 

Technical Support for the Advisory Board on 

Radiation & Worker Health Review of 

Effective Date: 

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NIOSH Dose Reconstruction Program Revision No. 

0 (Draft) 

Supplementary Comments on Revision 01 of 

Battelle-TBD-6000 Page 2 of 34 

Task Manager/Lead Author: 

___________________________ Date:____________ 

William C. Thurber 

Supersedes: 

N/A 

Project Manager: 

___________________________ Date:____________ 

John Stiver, MS, CHP 

Peer Reviewer(s): 

John Mauro 

John Stiver 

Record of Revisions
 

Revision 

Number 

Effective 

Date Description of Revision 

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TABLE OF CONTENTS 

Abbreviations and Acronyms ..........................................................................................................5 

1.0 Introduction..........................................................................................................................7 

2.0 Settling Velocity and Time for Equilibrium Deposition......................................................7 

3.0 Removal Rate.....................................................................................................................14 

4.0 Comparison of Site-Specific Air Concentrations with Generic Data Used in TBD6000....................................................................................................................................14 

4.1 TBD-6000 Values..................................................................................................15 

4.2 Site Comparisons...................................................................................................18 

4.2.1 Hanford Melt Plant Building .....................................................................18 

4.3 Simonds Steel and Saw..........................................................................................19 

4.4 Joslyn .....................................................................................................................20 

4.5 Bethlehem Steel .....................................................................................................21 

4.6 Conclusions............................................................................................................22 

5.0 Operations Not Explicitly Covered in TBD-6000 .............................................................22 

5.1 Chip Fires during Machining.................................................................................22 

5.2 Floor Sweeping ......................................................................................................23 

5.3 Outdoor Uranium Pit Burning ...............................................................................24 

6.0 Summary............................................................................................................................26 

References......................................................................................................................................28 

Attachment A: Derivation of Air Concentrations at Hanford Melt Plant Building......................30 

Attachment B: IREP Runs for Hypothetical Oxide Operator.......................................................31 
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LIST OF TABLES 

Table 1. Settling Rates of Oxide Dust at Various Sites throughout the Melt Plant Building .......9 

Table 2. Estimated Settling Velocities in Main Bay Using Adley Table XIII Settling 

Rates and Average Air Concentration of 1,400 μg/m .................................................10 3

Table 3. Terminal Settling Velocities Using Particle Size Measurements from Adley, 

Table XI ........................................................................................................................12 

Table 4. Time to Reach Equilibrium Surface Concentration......................................................13 

Table 5. Air Sampling Data for Facilities Rolling Uranium Rods..............................................15 

Table 6. Air Sampling Data for Facilities Forging Uranium.......................................................15 

Table 7. Air Sampling Data for Facilities Machining Uranium..................................................16 

Table 8. Air Sampling Data for Uranium Slug Production and Canning ...................................16 

Table 9. Air Sampling Data for Uranium Scrap Recovery .........................................................17 

Table 10. Hanford Melt Plant Building vs. TBD-6000 Values.....................................................18 

Table 11. Simonds Saw and Steel Natural Uranium Rolling vs. TBD-6000 Values....................19 

Table 12. Simonds Saw and Steel Uranium Forging vs. TBD-6000 Values................................20 

Table 13. Joslyn Rolling and Machining vs. TBD-6000 Values ..................................................20 

Table 14. Bethlehem Steel vs. TBD-6000 Values ........................................................................21 

Table 15. Air Concentrations from Burning of Uranium during Machining................................23 

Table 16. Air Concentrations of Uranium from Floor Sweeping .................................................23 

Table 17. Atmospheric Concentrations of Uranium at Hanford Melt Plant Outdoor 

Burning Operations.......................................................................................................24 
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ABBREVIATIONS AND ACRONYMS 

ABRWH Advisory Board on Radiation and Worker Health 

ACGIH American Conference of Governmental Industrial Hygienists 

AEC Atomic Energy Commission 

AM arithmetic mean 

AMAD activity median aerodynamic diameter 

atm atmosphere 

AWE Atomic Weapons Employer 

BZ breathing zone 

C surface concentration 

CEDE committed effective dose equivalent 

CFR Code of Federal Regulations 

DCAS Division of Compensation Analysis and Support 

DOL Department of Labor 

dpm/d disintegrations per minute per day 

dpm/m2

 disintegrations per minute per square meter 

dpm/m3 disintegrations per minute per cubic meter 

DWA daily weighted average 

g/m3 gram per cubic meter 

g-U/m3 gram of uranium per cubic meter 

GM geometric mean 

GSD geometric standard deviation 

ICRP International Commission on Radiological Protection 

IMBA Integrated Modules for Bioassay Analysis 

IREP Interactive RadioEpidemiological Program 

K Kelvin (degrees) 

kg/m3

 kilogram per cubic meter 

m meter 

MED Manhattan Engineering District 

mg U/ft2 milligram of uranium per square foot 

mrem millirem 

NIOSH National Institute for Occupational Safety and Health 
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NOTICE:

μg/cc microgram per cubic centimeter 

μg/cm3 microgram per cubic meter 

μg-hr/cc microgram per hour per cubic centimeter 

μg/m2 microgram per square meter 

μg/m3 microgram per cubic meter 

μm micrometer 

MMD mass median diameters 

m/s meters per second 

NRC Nuclear Regulatory Commission 

OCAS Office of Compensation Analysis and Support 

ORAUT Oak Ridge Associated Universities Team 

POC probability of causation 

rem Roentgen equivalent man 

SC&A S. Cohen and Associates (SC&A, Inc.) 

SEC Special Exposure Cohort 

SRDB Site Research Data Base 

TBD Technical Basis Document 

TLV-STEL Threshold Limit Value-Short-Term Exposure Limit 

TWA time-weighted average 

U3O8 uranium oxide 
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1.0 INTRODUCTION 

SC&A was recently tasked with reviewing several dose reconstructions, site profiles, and a 

petition evaluation report that relied on Battelle-TBD-6000 to provide the bases for completed 

dose reconstructions or possible future dose reconstructions (e.g., Joslyn). These reviews have 

provided additional insight into how TBD-6000 is used in practice and revealed some potential 

issues associated with using that document that were not apparent when the document was 

originally reviewed and proposed changes were discussed. SC&A had previously reviewed 

TBD-6000 (SC&A 2007) and based on our findings, the document was revised by NIOSH in 

2011 (Battelle 2011). These supplementary comments address four issues: 

 The suitability of using a terminal settling velocity of 0.00075 m/s and the time required 

to reach an equilibrium surface concentration 

 The attenuation rate for surface contamination 

 A comparison of site-specific air concentrations with generic data used in TBD-6000 

 Operations not explicitly covered in TBD-6000 

2.0 SETTLING VELOCITY AND TIME FOR EQUILIBRIUM 

DEPOSITION 

Based on its initial review of TBD-6000, SC&A recommended that NIOSH consider the surface 

contamination levels presented in a report by Adley et al. (1952) and in the Simonds Saw and 

Steel TBD (ORAUT 2011) in addition to the data from Harris and Kingsley 1959, upon which 

exposures in TBD-6000 were constructed. At that time, SC&A questioned the appropriateness 

of using a 0.00075 m/s settling rate, as well as the use of 7 days deposition to achieve an 

equilibrium surface concentration. The velocity of 0.00075 m/s is the theoretical terminal 

velocity based on Stokes Law settling for 5 μm AMAD spherical particles. 

In response to SC&A’s concerns, NIOSH issued white papers showing that use of a velocity of 

0.00075 m/s was claimant favorable based on an analysis of data in Adley et al. 1952, and that an 

equilibrium surface concentration could be achieved in 27 days (Allen 2009a, Allen 2009b). The 

NIOSH white papers were discussed at a meeting of the TBD-6000 Work Group on October 14, 

2009, and SC&A indicated general agreement with the NIOSH approach, although SC&A did 

not review in detail the calculations supporting the NIOSH conclusions at that time. 

In 2011, TBD-6000 was revised to reflect these additional data sources, as described in 

Section 3.4.2 (Exposures from Contaminated Surfaces) of Battelle-TBD-6000 (Rev. 01): 

When measured floor contamination rates are not available the contamination on 

the floor may be estimated from measured air concentrations. The level of 

surface contamination is determined by first calculating a terminal settling 

velocity for 5-μm activity mean aerodynamic diameter1

 (AMAD) particles. The 

1

 We believe that this should read “activity median aerodynamic diameter.” 
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calculated terminal settling velocity was 0.00075 meters per second. Next the 

amount of time necessary for the surface contamination to build up to an 

equilibrium value is needed. In order to determine this time, surface 

contamination values from Adley (Adley, Gill and Scott, 1952) and from Simonds 

Saw and Steel (AEC 1949) were used. Also, the inhalation values from Table 7.8 

were converted to airborne activity and used in this analysis. The geometric 

mean of the Table 7.8 airborne activity was compared to the geometric mean of 

the Adley surface contamination values. It was determined that with a settling 

rate of 0.00075 m/s, a 27 days settling period was necessary to match the Adley 

surface contamination values. The analysis indicated a settling time of 15 days 

was necessary to match the Simonds Saw and Steel contamination values. Both 

values are within a factor of two indicating reasonable agreement. Based on this 

analysis, the higher value was rounded up to 30 days and used in this document. 

Using a 30 day deposition time and a 0.00075 m/s settling rate, a deposition 

factor of 1944 meters can be calculated. The floor contamination level is then 

estimated as Floor Concentration (dpm/m2

) = Air Concentration (dpm/m3) × 

1944 meters. 

One of the key experiments reported in Adley2 involves a number of plates placed around the 

Hanford Melt Plant Building upon which contamination was allowed to accumulate over several 

months. The data were summarized by Adley in Table XIII (see Table 1 below) as settling rates 

(mg U/ft2 per day). However, the measured quantity on the plates would have been in units of 

mg U/ft2. Adley divided the measured quantities by the total days of exposure (either 158 days 

for winter samples or 117 days for spring samples) to obtain a settling rate. This approach 

assumes that the settling rate was a linear function of time. NIOSH used these settling rates and 

the estimated air concentration from Table IX of Adley to calculate settling velocities. The 

calculated settling velocities based on each plate were, with one exception, lower than the TBD6000 default assumption of a 0.00075 m/s terminal settling velocity for 5 μm AMAD particles. 

On this basis, NIOSH concluded that 0.00075 m/s was reasonable and claimant favorable. 

SC&A’s original concern about the use of the terminal settling velocity of 0.00075 m/s was not 

just about the validity of the numerical value of the settling velocity, but also whether the use of 

an air concentration coupled with the terminal settling velocity and a settling time resulted in a 

surface concentration that reflected all the processes that could contribute to the quantity of 

material that was present on the shop floor. For example, was part of the material on the floor 

large flakes that quickly dropped out of the air and were not captured by assuming Stoke’s Law 

settling of small particles? Such particles could be ground up by foot or vehicular traffic, be 

resuspended, and moved throughout the work area. However, the Melt Plant Building main bay 

plate samples in the west end of the bay showed little dependency on sampling height above the 

floor (Adley et al. 1952, Table XIII). According to the authors, “In this area the turbulence 

arising from daily activity in the plant apparently results in more even settling of dust at different 

heights.” In the east end of the main bay, on the other hand, some gradation in deposition with 

height was observed. Comparing the average settling rates for the east end and west end winter 

samples shows only about a 6% difference. Consequently, we believe that spatial differences 

 2

 Adley et al. 1952 will also be referred to as simply Adley in this report. 
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within the main bay related to sample height had little to no effect on the buildup of uranium on 

surfaces and can be ignored. 

 

Table 1. Settling Rates of Oxide Dust at Various Sites throughout the 

Melt Plant Building 

Settling Rates 

(mg Uranium/ft2

 per day) General Location Sampling Sites Winter 

Samples 

Spring 

Samples 

Main Bay – East End On floor in storage bay near extrusion line 

Atop muffle furnace at middle of north wall 

South wall on motor switchbox 

Atop rotary furnace – southeast edge 

Northeast corner of autoclave crane platform 

2.7 

1.16 

1.06 

0.70 

0.69 

* 

3.25 

1.99 

0.91 

0.67 

Main Bay – West End Atop cabinet by door at middle of north wall 

Atop instrument panel for oxidizing furnace 

On roof of shop 

On roof of vacuum pump room 

1.01 

1.11 

1.01 

1.64 

* 

* 

1.47 

2.75 

Furnace Room and 

Vacuum Pump Room 

On screen above bus bars 0.22 0.89 

Burnout Room Front edge of oven – on top 5.72 * 

Shop (Saw Room) Shelf behind lathe part of time; on table opposite 

lathe remainder of time 1.14 0.88 

Office and Toilet Area Atop file cabinet at east wall of office 0.28 0.21 

*Note: These samples lost by breakage of container, blowing away, or other accidental causes. 

 Source: Adley et al. 1952, Table XIII 

In reviewing the NIOSH approach, SC&A also developed concerns about the way the average 

air concentration was calculated. NIOSH took the weighted daily exposures for the nine jobs 

listed in Adley Table IX and converted those values to an average air concentration for each job 

assuming an 8-hour day. NIOSH determined the geometric mean (GM) for the nine jobs and 

used this value as the air concentration. It is not apparent that this approach properly represents 

the air concentration that would correlate with the surface deposition since it is related to a 

person’s location at various times during the work-day and not the air concentration at a 

particular location. To circumvent this problem, we used an average concentration of 

1,400 μg/m3

 for the main bay area of the Melt Plant Building. This value is based on an 

observation in Adley that, if the amount of uranium deposited in a day were uniformly 

distributed throughout the air in the Melt Plant Building, the air concentration would be 

1,400 μg/m3

. Specifically, Adley states, “If the 20 grams of U308 that settles out daily were 

dispersed evenly throughout the 500,000 cubic feet of the building, the resulting concentration of 

dust would be 28 times the maximum permissible level of 5 × 10-5 μg/cc.”

Using this average air concentration, effective or net settling velocities were calculated using the 

settling rates from Adley Table XIII. The estimated settling velocity based on all plates in the 

main bay taken individually and averaged together are summarized in Table 2. The settling 

velocities in Table BB are subject to interpretation as to what the Adley expression “settles out 

daily” means. The settling velocities in Table 2 assume that the average air concentration of 

1,400 μg/m3

 persists for 24 hours. Since the Melt Plant Building apparently operated on a single 

shift basis, the 20 grams that settle out daily could be that material which is generated during an 
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8-hour shift. Assuming a building height of 12 m (Gerber 1996), it would require 4.4 hours for a 

5 μm AMAD particle to fall from the roof to the floor. All particles would have settled out in 

12.4 hours. Thus, the average daily air concentration would be 1,150 μg/m3 (1,400 × 8/12.4 + 

700 × 4.4/12.4). With this interpretation, settling velocities in Table 2 would increase by a factor 

of 1.2. 

Table 2. Estimated Settling Velocities in Main Bay Using Adley Table XIII Settling 

Rates and Average Air Concentration of 1,400 μg/m3

Location Settling Rate 

mgU/ft2

/day 

Settling Rate 

μg/m2/day 

Measured Surf. 

Concentration 

μg/m2

Air 

Concentration 

μg/m3

Settling 

Velocity 

m/s 

Main Bay – winter 1.23 13,296 2,100,768 1,400 1.10E-04 

Main Bay – spring 1.84 19,872 2,325,024 1,400 1.64E-04 

Autoclave platform – winter 0.69 7,452 1,177,416 1,400 6.16E-05 

Autoclave platform – spring 0.67 7,236 846,612 1,400 5.98E-05 

Rod straightener – winter 1.06 11,448 1,808,784 1,400 9.46E-05 

Rod straightener – spring 1.99 21,492 2,514,564 1,400 1.78E-04 

Storage bay – winter 2.7 29,160 4,607,280 1,400 2.41E-04 

Oxide burning – winter 1.11 11,988 1,894,104 1,400 9.91E-05 

Shop roof – winter 1.01 10,908 1,723,464 1,400 9.02E-05 

Shop roof – spring 1.47 15,876 1,857,492 1,400 1.31E-04 

Vac pump rm roof – winter 1.64 17,712 2,798,496 1,400 1.46E-04 

Vac pump rm roof – spring 2.75 29,700 3,474,900 1,400 2.46E-04 

North wall cabinet – winter 1.01 10,908 1,723,464 1,400 9.02E-05 

Atop rotary furnace – winter 0.7 7,560 1,194,480 1,400 6.25E-05 

Atop rotary furnace – spring 0.91 9,828 1,149,876 1,400 8.13E-05 

Atop muffle furnace – 

winter 1.16 12,528 1,979,424 1,400 1.04E-04 

Atop muffle furnace – 

spring 3.25 35,100 4,106,700 1,400 2.90E-04 

  

All of the settling velocities are less than the terminal settling velocity for 5μm AMAD particles 

of 0.00075 m/s. The implications of this analysis are that the results do not change substantively 

whether one uses the uranium concentration in the breathing zone (BZ) or the overall average 

airborne uranium concentration for the purpose of deriving the deposition velocity. Possible 

reasons for these differences between the terminal settling velocity and the estimated settling 

velocities will be discussed subsequently. 

 

Using air concentrations based on daily weighted average (DWA) exposures, NIOSH also 

showed that, with one exception, the estimated settling velocities were less than the terminal 

settling velocity for 5μ AMAD particles. While we believe the approach taken here to estimate 

air concentrations is more robust, it does not change the conclusion reached by NIOSH that use 

of a terminal settling velocity of 0.00075 m/s is claimant favorable. 

 

There are several possible explanations as to why the estimated settling velocities (Table 2) are 

less than the terminal settling velocity for 5 μm AMAD particles. Possibilities include: 

 Corrections to the terminal settling velocity are needed to account for particle slip and 

lack of sphericity 
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 The particle diameters were less than 5 μm AMAD 

 The air concentration was lower than the estimated value of 1,400 μm/m3 used here 

 The measured settling rate is a net rate between deposition and removal 

We will examine each of these points to see to what extent the differences can be explained. 

Corrections to Terminal Settling Velocity 

The terminal settling velocity in air for a 1.7 μm diameter particle of uranium oxide (U3O8) in 

the Stoke’s Law flow regime is given by the equation (Whicker 2007): 

Vt = Dp

2

 × g × ρp/18μ 

where Vt – terminal settling velocity m/s 

Dp – physical particle diameter – 1.7E-06 m 

g – gravity acceleration – 9.81 m/s 

ρp – U3O8 particle density – 8380 kg/m3

μ – viscosity of air – 1.8E-05 kg/m-s 

For this example, Vt = 7.33E-04 m/s. This equation applies to rigid spherical particles. For 

particle physical diameters of less than about 20 μm, Stoke’s Law reasonably reflects the effect 

of the drag force exerted by the air on a particle falling under the influence of gravity. 

Alternatively, if we assume 5 μm AMAD particles (density – 1,000 kg/m3), then Vt = 

7.57E-04 m/s, which is essentially the same as 7.5 E-04 m/s used by NIOSH in its modeling and 

is essentially the same as a particle with a 1.7 μm physical diameter. 

For small diameter particles (less than about 10 μm), the particles may “slip” between air 

molecules and not be retarded by the drag force of the air. The slip correction factor is given by 

the following equation (Flagan and Seinfeld 1988): 

Cc = 1 + λ/Dp [2.514 + 0.8exp(-0.55Dp/λ)] 

where Cc – slip correction factor 

λ – mean free path of air molecules - 0.0651 μm at 1 atm and 298 K 

For 1.7 μm physical diameter particles, Cc is 1.098; this correction would increase the terminal 

velocity to 0.00080 m/s. 

In addition to the slip correction factor, it is appropriate to consider a correction for the fact that 

the particles are not perfect spheres. It is proposed in ICRP 1994 that a factor of 1.5 be added to 

the denominator of the equation for the terminal settling velocity. This would reduce the 

terminal velocity for 5 μm AMAD particles to 0.00052 m/s. Thus, the use in TBD-6000 of a 

terminal velocity of 0.00075 m/s is conservative since it overstates the amount of activity 

deposited on a surface. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Using a terminal velocity of 0.00052 m/s and an air concentration of 1,400 μ g/m3 results in an 

average calculated surface concentration of 9.94E06 μ g/m2 for the main bay (winter), which is 

4.8 times larger than the average measured surface concentration for the main bay (winter) using 

the settling rate shown in Table BB. As noted above, the sphericity correction factor of 1.5 was 

taken from ICRP 1994. This factor is characterized as the reference or typical value with 

reported values ranging from 1.1 to 1.9. Increasing this factor to the maximum value of 1.9 

would reduce the terminal velocity to 0.00041 m/s and the calculated surface concentration to 

7.85E+06 μ g/m2

—a result that is still well above the measured value. Thus, it is not possible 

that adjustments to the terminal velocity for slip and sphericity can explain most of the difference 

between the measured and calculated values. 

Smaller Particles 

It is also possible that the terminal velocity was lower because the particles had an AMAD of 

less than 5 μ m. Adley et al. 1952 provides measurements in Table XI documenting mass median 

diameters (MMD) from 26 sets of particle measurements. Mass median diameters (MMDs) 

ranged from 0.7 to 3.4 μ m with a median value for the 26 sets of 1.4 μ m and an average value of 

1.7 μ m. Relevant data are summarized in Table 3. 

Table 3. Terminal Settling Velocities Using Particle Size Measurements from Adley,
 

Table XI
 

Sample Particle Size 

(μmeters) 

CI-26 0.7 

CI-3 0.9 

CI-28 1 

CI-4 1.1 

CI-8 1.1 

CI-9 1.1 

CI-12 1.1 

CI-5 1.2 

CI-7 1.2 

Sample Particle Size 

(μmeters) 

CI-15 1.3 

CI-13 1.3 

CI-6 1.4 

CI-21 1.4 

CI-2 1.4 

CI-18 1.7 

CI-27 1.9 

CI-1 1.9 

CI-10 2 

Sample Particle Size 

(μmeters) 

CI-17 2.2 

CI-24 2.2 

CI-16 2.3 

CI-19 2.5 

C-14 2.7 

CI-22 3 

CI-23 3.2 

CI-25 3.4 

Since the average physical particle diameter of 1.7 μ m is basically the same as a 5-μ m AMAD 

particle, it does not appear that the differences between measured and calculated values are 

attributable to reduced velocities associated with a particle size of less than the assumed 5 μ m 

AMAD when averaged over time and space. 

Lower Air Concentration 

For the calculations presented here, we used an average air concentration of 1,400 μ g/m3 based 

on an estimate provided in Adley. Adley also provides data on all the individual measurements 

in Tables II through VII. The average of all samples in the main bay is about 9,500 μ g/m3 and 

the estimate of the standard error of the mean is 3,480 μg/m3 . Assuming the standard error of 

mean has an approximate normal distribution, there is a 1% probability that the mean could be 

less than 1,400 μ g/m3 . On this basis, it does not appear that the lower observed uranium 

accumulation values observed in the plates, as compared to the levels predicted by the Stokes 

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law, are due to the possibility that the average airborne dust loading of uranium used in the 

Adley calculations was underestimated. 

Measured Settling Rate is Net of Deposition and Removal Processes 

Plates used to measure the settling rates in Adley were exposed for several months of conditions, 

which could alter the amount deposited on the plates. For example, air drafts could remove 

deposited material resulting in equilibrium between deposition and removal mechanisms where 

equilibrium was reached prior to the termination of the plate experiments. The time to reach 

equilibrium can be approximated by: 

Measured surface concentration (mg U/m2

) ÷ air concentration (μ g/m3) ÷ settling velocity (m/s) 

The measured surface concentration is taken from Table 2 and the settling velocity is the 

terminal settling velocity for 5 μ m AMAD particle adjusted for slip and lack of sphericity (i.e., 

0.00052 m/s). The results, which are summarized in Table 4, suggest that some removal 

mechanisms were active, offsetting the deposition on the plates. Using a velocity of 0.00052 m/s 

for 5 μ m AMAD particles (velocity adjusted for slip and sphericity) and an air concentration 

1,400 μ g/m3, the time to reach equilibrium based on main bay averages is 33 to 37 days. This 

value is in close agreement with the 30 days assumed in Revision 01 of TBD-6000. However, it 

should be noted that in some areas within the Main Bay, times of up to 73 days were required to 

reach equilibrium. The 95th percentile of the 15 Main Bay samples is 69 days to reach 

equilibrium. The estimate for the storage bay is 73 days (i.e., the 97th percentile). Based on 

these data, the claimant-favorable approach would be to use a value of 70 days to achieve an 

equilibrium surface concentration, where the rate of deposition equals the rate of removal. 

However, as noted previously in the discussion of Table 2, an alternative, and perhaps more 

likely interpretation of the data in Adley is that the dust settled in 12.4 hrs. Under this 

interpretation, the time to reach equilibrium would increase by 20%, suggesting an upper bound 

of 84 days. 

Table 4. Time to Reach Equilibrium Surface Concentration 

(Vt = 0.00052 m/s, Air Concentration = 1,400 μ g/m3) 

Location Days to Equilibrium 

Main Bay – winter 33 

Main Bay – spring 37 

Autoclave platform – winter 19 

Autoclave platform – spring 13 

Rod straightener – winter 29 

Rod straightener – spring 40 

Storage bay – winter 73 

Oxide burning – winter 30 

Shop roof – winter 27 

Shop roof – spring 30 

Vac pump room roof – winter 44 

Vac pump room roof – spring 55 

North wall cabinet – winter 27 

Atop rotary furnace – winter 19 

Atop rotary furnace – spring 18 

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Table 4. Time to Reach Equilibrium Surface Concentration 

(Vt = 0.00052 m/s, Air Concentration = 1,400 μ g/m3) 

Location Days to Equilibrium 

Atop muffle furnace – winter 31 

Atop muffle furnace – spring 65 

3.0	 REMOVAL RATE 

The change in surface concentration (C) over time can be expressed by the equation: 

dC/dt = R-λC 

where R is the deposition rate and λ is the removal rate. The average surface concentration (C) 

from all of the Main Bay Adley data is 2.18E+06 μ g/m2 . The deposition rate (R) is the air 

concentration (μ g/m3

) times the average settling velocity (m/s) or 0.73 μ g/m2/s (1,400 μ g/m3 × 

0.00052 m/s). At equilibrium, the removal constant λ is R/C or 3.3E-07/s or 0.028/day. 

It is noteworthy that the removal rate of 0.035/day is considerably higher than the removal rate 

of 0.00067/day developed in ORAUT-OTIB-0070 (ORAUT 2012) for the residual period. 

However, this difference is not surprising, since the rates in OTIB-0070 were based on assuming 

exponential decay between a starting point and an end point based on a measurement taken years 

afterward with no knowledge of whether the end point could actually have occurred much 

earlier. The value of 0.00067/day for the removal rate was the average of rates from four sites 

(Blockson, Dow Chemical, Simonds Saw and Steel, and General Atomic). In the case of Dow, 

for example, the duration of the residual period was 45 years. It is certainly possible that natural 

attenuation processes had reduced the residual contamination to the end point value in 

significantly less than 45 years. The calculations presented here support the position that the 

OTIB-0070 approach regarding time to reach equilibrium is claimant favorable. 

4.0	 COMPARISON OF SITE-SPECIFIC AIR CONCENTRATIONS 

WITH GENERIC DATA USED IN TBD-6000 

This section compares generic air concentrations in the TBD-6000 (Battelle 2011) to the sitespecific time-weighted air exposure values for the Hanford Melt Plant Building (Adley et al. 

1952), Simonds Saw and Steel (ORAUT 2011), Joslyn (NIOSH 2012), and Bethlehem Steel 

(NIOSH 2010). Section 4.1explains the TBD-6000 values and how they were determined. 

On several occasions in the past, SC&A has raised questions about the implementation of TBD6000 in dose reconstruction. The questions did not involve the underlying dataset from Harris 

and Kingsley (1959) from which the data in TBD-6000 were derived, but rather how the data 

were used in dose reconstruction. The default NIOSH approach for selecting input to calculate 

the probability of causation (POC) with IREP has been to use a lognormal distribution with the 

GM taken from the appropriate table in TBD-6000 and assume a geometric standard deviation 

(GSD) of 5. NIOSH has argued that, by selecting conservative data from Harris and Kingsley, 

assuming a GSD of 5, choosing from several tasks the highest air concentration for a particular 

operation and using the 99th percentile for calculating the POC, the approach is claimant 

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favorable. As the discussion that follows will show, use of the GM from TBD-6000 with a GSD 

of 5 as compared to constant high-end exposure values from specific sites results in comparable 

POCs and substantiates the plausibility of the NIOSH approach. 

Theoretically, there could be situations (e.g., exposures are near the 95th percentile of an assumed 

lognormal distribution) where use of the full lognormal distribution might result in a slightly 

lower POC than would use of the 95th percentile dose as a constant input into IREP. However, 

the likelihood that a worker was continuously exposed to very high concentrations is low, and 

with either calculational approach, the POC would be well above 50% for lung cancers. 

 

4.1 TBD-6000 VALUES 

The following tables are from the TBD-6000 and contain the values used to compare daily 

weighted exposures for workers at Joslyn, Simonds, Adley, and Bethlehem with TBD-6000 

values based on comparable job categories for workers. 

Table 5. Air Sampling Data for Facilities Rolling Uranium Rods

Job Category Short duration measured air 

concentrations (dpm/m3

) 

Geometric Mean 

(dpm/m3) 

Furnace Operator 180 80.5 

Roughing Roll Operator 1,620–13,700 4,710 

Finishing Roll Operator 800–8,400 2,590 

Cooling 1,470 657 

Stamper 1,940 868 

Drag Down Operator 730 327 

Shear Man 1,500 671 

Operator DWA – 3,533 

General Laborer DWA – 651 

Supervisor DWA – 326 

Clerical DWA – 33 

 Source: Battelle 2011, Table 7.3 

Table 6. Air Sampling Data for Facilities Forging Uranium 

Job Category DWA Measured air 

concentrations (dpm/m3

) 

Geometric Mean 

(dpm/m3) 

Press forging – salt bath 1.7 0.8 

Press forging – press 16 7.2 

Press forging – quench tank 6.2 2.8 

Hammer forging – front hammer operator, DWA 2,480 1,110 

Hammer forging – backside hammer operator, DWA 2,610 1,170a

Hammer forging – furnace operator & helper, DWA 810 362 

Operator, DWA – 1,170 

General Laborer, DWA – 362 

Supervisor, DWA – 181 

Clerical, DWA – 18 

a – Should be 715 dpm/m3. 

 Source: Battelle 2011, Table 7.4 
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Table 7. Air Sampling Data for Facilities Machining Uranium 

Job Category DWA Measured air concentrations 

(dpm/m3

) 

Geometric Mean 

(dpm/m3) 

Automatic lathe, DWA 200–300 245 

Turret lathe, DWA 150 67 

Facing, DWA 100 45 

Cutoff, DWA 100 45 

Milling, DWA 100 45 

Slotting, DWA 100 45 

Drill, DWA 20 9 

Radius Cutting, DWA 100–300 173 

Milling, DWA 40 18 

Shaping, DWA <10 4 

Planning, DWA <10 4 

Surface Grinder, DWA 2000–5000 3160 

Portable Grinder, DWA 400 179 

Belt Sander, DWA 3000 134 

Centerless Grinder, DWA 5000–6000 5480 

Straightening, DWA 1500–1900 1690 

Operator DWA – 5480 

General Laborer DWA – 2740 

Supervisor DWA – 1370 

Clerical DWA – 137 

 Source: Battelle 2011, Table 7.5 

Table 8. Air Sampling Data for Uranium Slug Production and Canning 

Job Category Short duration measured air 

concentrations (dpm/m3

) 

Geometric Mean 

(dpm/m3) 

Stamping slug 590 264 

Filing slug 440 197 

Wire-brush cleaning die section 260 116 

Cleaning end slugs 220 98 

Cleaning die liners 220 98 

Operator DWA – 198a

General Laborer DWA – 99 

a – Should be 121 dpm/m3

 Source: Battelle 2011, Table 7.6 
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Table 9. Air Sampling Data for Uranium Scrap Recovery 

Job Category DWA Measured air concentrations 

(dpm/m3

) 

Geometric Mean 

(dpm/m3) 

Straightening, DWA 1,500–1,900 1,690 

Drawing, DWA Nil 4 

Swaging, DWA <10 4 

Degreasing, DWA 260 116 

Briquetting, DWA 250 112 

Briquette discharge, DWA 600 268 

Operator DWA – 1,690 

General Laborer DWA – 845 

Supervisor DWA – 423 

Clerical DWA – 42 

 Source: Battelle 2011, Table 7.7 

There are several generalized Job Categories listed in the tables above (Operator, General 

Laborer, Supervisor, and Clerical). The values associated with each of these generic job 

categories were determined by assessing the relevant, available data and using the “worst case” 

value to determine the Operator Job Category value. It is assumed that, on average, operators 

were exposed to this worst case value 75% of the time. In other words, the “worst case” value 

was multiplied by 0.75 to obtain the DWA for the Operator Job Category. For example, in 

Table 5, there are four types of operators (Furnace Operator, Roughing Roll Operator, Finishing 

Roll Operator, and Drag Down Operator). Of these operators, the Roughing Roll Operator has 

the highest GM exposure value (4,710 dpm/m3). Therefore, this value is used to determine the 

generic Operator DWA for facilities rolling uranium rods. The GM air concentration of 

4,710 dpm/m3 is multiplied by 0.75 (the assumed fractional exposure time) to obtain a DWA of 

3,533 dpm/m3

 as listed in the table. In the case of operations included in Tables 6, 7, and 8, the 

data were reported in the original source document (Harris and Kingsley 1959) as DWA values, 

so no further adjustment was required. 

For entries in the above tables from TBD-6000, where a range of values was not reported, the 

single value measured air concentration was assumed to be the arithmetic mean (i.e., the 

expected value). The GM was calculated using the arithmetic mean and a GSD of 5. This can 

be done using the following equation from Table 2.2 in Strom 2007: 

 x = exp(μ + σ

2

/2) 

where x is the arithmetic mean, μ = ln GM, and σ = ln GSD. 

In reviewing the data in the above tables from TBD-6000, it appears that some of the GM values 

are in error. Consider the General Laborer in Table 5. According to that report, the General 

Laborer DWA is based on the Stamper job category adjusted for 75% exposure (Stamper GM of 

868 dpm/m3 × 0.75 = 651 dpm/m3). However, the Stamper arithmetic mean (AM) is 

1,940 dpm/m3. Applying the above equation, the calculated GM is 531 dpm/m3, not 868 

dpm/m3

, as shown in Table 5. This would also affect the generic supervisor and generic clerical 

worker, whose exposures are factored from the General Laborer. Another example is the forging 

operator in Table 6, whose DWA GM is listed as 1,170 dpm/m3

, but we calculate a DWA GM of 
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715 dpm/m3

. NIOSH needs to check the GM calculations in all tables to insure that the GMs are 

correct. 

Arithmetic Mean 

In the comparison tables below, the TBD-6000 values are expressed as the GM and the AM. We 

believe that the AM serves as a better comparison to the DWA sample data from the four sites. 

The AM can be determined if one knows the GM and the GSD. The default assumption in the 

TBD-6000 is that the GSD = 5. We are not suggesting that the AM be used as the basis for dose 

reconstruction, but rather that the DWA AM is the appropriate basis of comparison for the 

generic TBD-6000 values with DWAs reported for various specific sites. 

4.2 SITE COMPARISONS 

The following four sections compare the sample values found at particular sites to the values 

found in the TBD-6000. 

4.2.1 Hanford Melt Plant Building 

Data on uranium fabrication operations at the Hanford Melt Plant Building were taken from 

Adley et al. 1952 and are summarized in Table 10. 

Table 10. Hanford Melt Plant Building vs. TBD-6000 Values 

Hanford (Adley)* DWA 

(dpm/m3

) 

TBD-6000 Equivalent 

Description 

(TBD-6000 Table No.) 

GM 

(dpm/m3) 

AM 

(dpm/m3) 

Is TBD-6000 

Limiting?a

Furnace Operator 3,013 Scrap Recovery Operator (7.7) 1,690 6,171 Yes 

Furnace Assistant 1,229 Scrap Recovery Operator (7.7) 1,690 6,171 Yes 

Saw Room Operator 4,243 Machining Operator (7.5) 5,480 20,010 Yes 

Oxide Operator 12,400 Scrap Recovery Operator (7.7) 1,690 6,171 No 

Rod Handler 384 General Laborer (7.7) 845 3,085 Yes 

Autoclave Operator 80 Slug Production Operator (7.6) 198 723 Yes 

Rod Receiving-unloading 1080 General Laborer (7.3) 651 2,377 Yes 

Rod Receiving-weighing 116 General Laborer (7.3) 651 2,377 Yes 

Rod Receiving-stacking 456 General Laborer (7.3) 651 2,377 Yes 

a – Based on comparison of DWA and AM. 

*The Adley et al. 1952 report provides nine time-weighted average air exposure values in Table IX. The values 

are presented in units of x10-5 μg-hrs/cc-day. 

Analysis: With the exception of the Oxide Operator, TBD-6000 is limiting for all Hanford (Adley) job 

descriptions. 

The only DWA that exceeds the TBD-6000 average is for the Oxide Operator whose exposure is 

at the 84th percentile of a lognormal distribution. However, as discussed in Adley, the Furnace 

Assistant, the Saw Room Operator, and Oxide Operator actually rotated jobs from day-to-day, so 

the adjusted DWA for each would be 5,957 dpm/m3

, a value below the TBD-6000 AM. 

An observation from this table (and the tables that follow) is that in a majority of cases, the GM 

values in TBD-6000 are higher than the DWA values for the data at individual sites (such as in 
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Table 10 for the Hanford Melt Plant). However, even in the cases where the TBD-6000 GM is 

lower than the DWA (as is the case in Table 10 for the Oxide Operator), the use of a GSD of 5 

on the GM as input to IREP results in a POC that is comparable to what one would derive if a 

fixed higher value were used. This occurs because the POC is derived at the 99th percentile 

level, and a GSD of 5 generally results in a very claimant-favorable POC, even though the actual 

DWA for the operator at the facility is higher than the TBD-6000 GM [and greater than the 

arithmetic mean (AM) for the Oxide Operator in Table 10]. 

To demonstrate this, we compared the POC for a hypothetical oxide operator whose 1-year 

intake in an IMBA/IREP simulation was based on a constant air concentration of 12,400 dpm/m3

and in the other simulation was based on a GM of 1,690 dpm/m3

 and a GSD of 5. In both 

examples, the POCs for lung cancer were comparable, being 99.0% for the constant air 

concentration and 98.6% for the lognormal air concentration. Details are summarized in 

Attachment B. 

4.3 SIMONDS STEEL AND SAW 

Air samples were taken during natural uranium rolling operations at Simonds Saw and Steel on 

15 dates between October 27, 1948, and January 21, 1953 (ORAUT 2011, Table 7). These 

highest air concentrations were observed during the initial sampling (October 27, 1948), so only 

those samples (AEC 1948) are included here for comparison with TBD-6000 in Table 11. 

Table 11. Simonds Saw and Steel Natural Uranium Rolling vs. TBD-6000 Values 

Simonds Saw and Steel 

TBD 

DWA 

(dpm/m3

) 

TBD-6000 Equivalent 

Description 

(TBD-6000 Table No.) 

GM 

(dpm/m3) 

AM 

(dpm/m3) 

Is TBD-6000 

Limiting?a

Foreman 1,760 Supervisor (7.3) 326 1,190 No 

West side roller #1 1,620 Rolling Operator (7.3) 3,533 12,901 Yes 

West side roller #2 797 Rolling Operator (7.3) 3,533 12,901 Yes 

East side roller #1 13,700 Rolling Operator (7.3) 3,533 12,901 No 

East side roller #2 8,394 Rolling Operator (7.3) 3,533 12,901 Yes 

Pressure quencher 1,471 General Laborer (7.3) 651 2,377 Yes 

Drag down operator 620 General Laborer (7.3) 651 2,377 Yes 

Furnace man 527 General Laborer (7.3) 651 2,377 Yes 

Rod stamper 1,944 General Laborer (7.3) 651 2,377 Yes 

a – Based on comparison of DWA and AM. 

Analysis: TBD-6000 is limiting for all Simonds Saw and Steel job descriptions except for the Foreman and East 

Side Roller #1. These values are slightly higher than the DWA values for the arithmetic mean. 

Values were also reported for rolling enriched uranium (either 2.75 or 7.2% U-235) on a 10-in 

mill (ORAUT 2011, Table 12). The highest DWA (stranner, north side) was 9,001 dpm/m3

, a 

value less than the TBD-6000 DWA value of 12,901 dpm/m3

 for a rolling operator. 

Limited uranium forging operations were also conducted at Simonds Saw and Steel. Air 

concentrations from two campaigns were reported in Tables 14 and 15 of ORAUT 2011 and are 

summarized here in Table 12. The highest average BZ value was 20,000 dpm/m3

 for a tong man 

on the east side of the forge. Using the TBD-6000 methodology, the DWA associated with this 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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measurement would be 15,000 dpm/m3 (75% of the expected value). The comparable value from 

Table 7.4 of TBD-6000 would be 2,610 dpm/m3 (DWA AM) and the 95th percentile value for 

TBD-6000 would be 36,800 dpm/m3 . The adjusted value of 15,000 dpm/m3 at Simonds is 

encompassed within the 95th percentile of the lognormal distribution. This example is similar to 

the Oxide Operator example discussed above where the hypothetical POC was essentially the 

same whether a constant dose based on the measured air concentration or a lognormal dose based 

on the TBD-6000 GM and a GSD of 5 are used. The DWA for several other operations is above 

the TBD-6000 AM, but less than the 84th percentile (for the Operator, east side forge). 

Table 12. Simonds Saw and Steel Uranium Forging vs. TBD-6000 Values 

Simonds Saw and Steel TBD DWA 

(dpm/m3

)* 

TBD-6000 Equivalent 

Description 

(TBD=6000 Table No.) 

GMb 

(dpm/m3) 

AM 

(dpm/m3) 

Is TBD-6000 

Limiting?a 

Operator, east side of forge 8,250 Operator DWA (7.4) 1,170 2,610 No 

Tong Man, east side of forge 15,000 Operator DWA (7.4) 1,170 2,610 No 

Hammer operating position 

downward 270 (avg. of 3) Operator DWA (7.4) 1,170 2,610 Yes 

Charg. Atop unit 253 (avg. of 3) Operator DWA (7.4) 1,170 2,610 Yes 

NW corner of hammer- two 

ingots 2,025 (avg. of 2) Operator DWA (7.4) 1,170 2,610 Yes 

Around hammer 2,895 (avg. of 4) Operator DWA (7.4) 1,170 2,610 No 

Opening furnace door 

removing ingot 3,375 Operator DWA (7.4) 1,170 2,610 No 

SW of 7 ton hammer 3,450 (avg. of 3) Operator DWA (7.4) 1,170 2,610 No 

NE of 7 ton hammer 1,208 (avg. of 4) Operator DWA (7.4) 1,170 2,610 Yes 

* BZ average multiplied by 0.75 for comparison with TBD-6000.
 

a – Based on comparison of DWA and AM.
 

b – The corrected GM based on an AM of 2,610 dpm/m3 from Table 7.3 of TBD-6000 should be 715 dpm/m3 

.
 

4.4 JOSLYN 

Data on uranium fabrication operations at Joslyn were taken from NIOSH 2012 and are 

summarized in Table 13. 

Table 13. Joslyn Rolling and Machining vs. TBD-6000 Values 

Joslyn Work Area/ 

Job Description 

DWA 

(dpm/m3

) 

TBD-6000 Equivalent 

Description 

(TBD-6000 Table No.) 

GM 

(dpm/m3

) 

AM 

(dpm/m3) 

Is TBD-6000 

limiting?a 

18” Rough Roll East 3,322 Rolling Operator (7.3) 3,533 12,901 Yes 

18’ Rough Roll West 375 Rolling Operator (7.3) 3,533 12,901 Yes 

Roller Foreman 725 Supervisor (7.3) 326 1,190 Yes 

Ass’t Foreman 725 Supervisor (7.3) 326 1,190 Yes 

Furnace Heaters 16 General Labor (7.3) 651 2,377 Yes 

Recorder 16 General Labor (7.3) 651 2,377 Yes 

12” Rough Roll East 605 Operator (7.3) 3,533 12,901 Yes 

12” Rough Roll West 570 Operator (7.3) 3,533 12,901 Yes 

Drag Down (Billet) 310 General Labor (7.3) 651 2,377 Yes 

9” Finishing Roll East 16,542 Operator (7.3) 3,533 12,901 No 

9” Finishing Roll West 5,791 Operator (7.3) 3,533 12,901 Yes 

Quench Tank 155 General Labor (7.3) 651 2,377 Yes 

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Table 13. Joslyn Rolling and Machining vs. TBD-6000 Values
 

Joslyn Work Area/ 

Job Description 

DWA 

(dpm/m3

) 

TBD-6000 Equivalent 

Description 

(TBD-6000 Table No.) 

GM 

(dpm/m3

) 

AM 

(dpm/m3) 

Is TBD-6000 

limiting?a 

Draggers 831 General Labor (7.3) 651 2,377 Yes 

Rod Stamper 242 General Labor (7.3) 651 2,377 Yes 

Rod Bundler 128 General Labor (7.3) 651 2,377 Yes 

Lathe Operator 12 Machining Operator (7.5) 5,480 20,010 Yes 

Centerless Grinder 100 Machining Operator (7.5) 5,480 20,010 Yes 

Grinder (portable) 277 Machining Operator (7.5) 5,480 20,010 Yes 

Cutomatic 191 Machining Operator (7.5) 5,480 20,010 Yes 

Analysis: With the exception of the 9” Finishing Roll Operator East, TBD-6000 is limiting for all Joslyn job 

descriptions. 

a – Based on comparison of DWA and AM. 

The DWA for the Finishing Roll Operator East is at the 83rd percentile of a lognormal 

distribution. All other DWAs are less than the AM. 

4.5 BETHLEHEM STEEL 

Only a limited number of BZ samples were taken at Bethlehem Steel and no DWA values were 

reported (Bethlehem 1952, Heatherton 1952). The BZ samples were for billet stamping and rod 

shearing operations only. Consequently, we used the TBD-6000 approach and multiplied the 

expected or average values by 0.75. We presume that these activities would be assigned to the 

Operator job category for uranium rolling. Results are summarized in Table 14 and compared 

with generic TBD-6000 values. 

Table 14. Bethlehem Steel vs. TBD-6000 Values 

Bethlehem DWA* 

(dpm/m3

) 

TBD-6000 Equivalent 

Description 

GM 

(dpm/m3) 

AM 

(dpm/m3) 

Is TBD-6000 

Limiting?a 

Shear Operator set-up 

And cut 1 rod 4 cuts 4 Rolling Operator 

(Table 7.3) 3,533 12,901 Yes 

Kickoff for Shear Rods 26 Rolling Operator (7.3) 3,533 12,901 Yes 

Kickoff of Sheared Rods 6 Rolling Operator (7.3) 3,533 12,901 Yes 

Kickoff of Sheared Rods 61 Rolling Operator (7.3) 3,533 12,901 Yes 

Kickoff of Sheared Rods 34 Rolling Operator (7.3) 3,533 12,901 Yes 

Shear 1 rod 4 cuts 270 Rolling Operator (7.3) 3,533 12,901 Yes 

Shear 2 rods 8 cuts 149 Rolling Operator (7.3) 3,533 12,901 Yes 

Shear 3 rods 13 cuts 80 Rolling Operator (7.3) 3,533 12,901 Yes 

Shear 3 rods 12 cuts 119 Rolling Operator (7.3) 3,533 12,901 Yes 

Stamping Billets by Shear 2,483 

(avg. of 3) Rolling Operator (7.3) 3533 12,901 Yes 

*BZ multiplied by 0.75 to compare with TBD-6000. 

a – Based on comparison of DWA and AM. 

Analysis: For Bethlehem, all DWA-adjusted BZ samples less than TBD-6000. 

In addition to the limited BZ samples included in Table 14, a larger number of process and 

general area air samples were also taken at Bethlehem (Bethlehem 1952, Heatherton 1952). 

None of these samples exceeded the TBD-6000 AM for a generic rolling operator. 

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4.6 CONCLUSIONS 

In the preceding tables, those values for DWAs at the various sites that exceed the AM DWAs 

from TBD-6000 are highlighted. None of the values exceed the 95th percentile, indicating that 

the operations in TBD-6000 characterized here would be claimant favorable if the 95th percentile 

of the lognormal distribution is used in dose reconstruction. However, this is not the NIOSH 

default approach, which uses the full lognormal distribution with the GM from TBD-6000 and a 

GSD of 5. For the high-end site-specific examples provided here, the NIOSH approach produces 

results that are at least comparable to those using the high-end site-specific values. Hence, 

overall, the data and strategy adopted in TBD-6000 for internal intakes is found to be 

fundamentally sound and claimant favorable. 

5.0 OPERATIONS NOT EXPLICITLY COVERED IN TBD-6000 

There are several operations that took place at early AWE facilities and are not explicitly 

covered in TBD-6000 that could have significant impacts on dose reconstructions. These 

involve practices such as vigorous floor sweeping, indoor chip fires during machining uranium, 

and outdoor uranium pit burning. This section provides some information on these practices. 

5.1 CHIP FIRES DURING MACHINING 

Uranium fires during machining have been documented since the early days of the Manhattan 

Project. In a 1943 letter, DuPont summarized the situation and identified the types of protective 

measures that should be undertaken to keep the process under control (Daniels 1943): 

The turnings have proved to be highly inflammable and subject to spontaneous 

ignition. Several experiments have been conducted at Herring-Hall-Marvin Safe 

Company, Hamilton, Ohio, and Baker Brother, Inc., Toledo, Ohio, and in addition 

there have been a number of accidental fires, of which at least three were 

spontaneous. Fires of quantities ranging from several pounds to several hundred 

pounds have been experienced and a number of extinguishers have been tried. 

Records of this work are available in our files. While the work to date does not 

constitute an exhaustive survey of the problem, we believe that it is now safe to 

outline precautionary and protective measures. 

Thus, as early as 1943, handling methods to reduce the consequences of uranium fires were well 

documented. This information was periodically updated, as demonstrated by a 1950 report 

authored by Kehoe et al. (1950) of the New York Operations Office of the AEC. That report 

suggested safe procedures for storage, laboratory handling, disposal, and shipment of uranium 

scrap. The report also describes the best procedures for extinguishing uranium scrap fires. 

Harris and Kingsley (1959) also noted that fires during uranium machining occur frequently, and 

they provide extensive guidance on practices that should be used to prevent such fires. These 

authors do not provide specific data on this issue, and it is not known if effects of chip burning 

are included in the quantitative machining data that they do provide. However, some relevant 

information is included in their discussion of chip briquetting during scrap recovery, where they 

note that: 
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 The operator of the machine may receive an excessive exposure, primarily 

working at the discharge of briquetting machine. Here the concentration of 

uranium has been found to average 600 d/m/M3

. The sources of contamination 

are the fume emanating from the burning edges of the briquette and that from 

burning chips which accompany the briquettes as they are ejected from the 

machine die. These fumes result from uranium ignited by the heat created in the 

press. 

Assuming that air concentrations from the burning of chips during briquetting are similar to 

those arising from chip burning during uranium machining, then the effects of chip burning 

during machining are encompassed by the TBD-6000 machining operator whose AM DWA is 

20,010 dpm/m3. Adley provides several measurements taken during various machining 

operations where either burning or fume generation are cited. These measurements are presented 

in Table 15. 

Table 15. Air Concentrations from Burning of Uranium during Machining 

Air Concentration Operation (10-5 μg/cc) (dpm/m3

) 

Turning down deeply pitted billet. Sparks and burning metal. 27 410 

Deep cut with dull tool. Heavy fume. 97 1,470 

Same time and place as above sample. 20 304 

Sampled during three cuts; dull saw much fume. 12 182 

Sample at breathing level only; much fume from saw case vent. 154 2,340 

Fume from vent of saw case – fume barely visible 20-minute sample. 122 1,850 

Sawing large chunks of metal from crucible. Sample 15” above cut. 

Considerable fume observed. 127 1,930 

The individual air concentration measurements made by Adley where machining was 

accompanied by uranium burning are all substantially less than the generic DWA for machining 

based on Table 7.5 of TBD-6000. Hence, we believe that the generic uranium dust loading used 

in TBD-6000 for machining operations accounts for the possibility that uranium fires occurred 

periodically at these facilities. 

5.2 FLOOR SWEEPING 

Adley provided dust concentration data related to floor sweeping as summarized in Table 16. 

Table 16. Air Concentrations of Uranium from Floor Sweeping 

Air Concentration Operation (10-5 μg/cc) (dpm/m3

) 

Sweeping Time 

(hr/day) 

Sweeping floor after stripping billets and sawing 86 1,310 0.1 

Sweeping after emptying crucibles 582 8,850 0.1 

Sweeping floors in oxide burner area using saw dust 5.9 90 0.5 

Sweeping entire area, using saw dust sweeping compound (avg. of 2) 39.5 600 0.2 

Sweeping in main bay [non-production areas] of building 1.1 17 Not stated 

Sweeping floor at opposite end of furnace 35 532 Not stated 
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The highest observed exposure of 8,850 dpm/m3

 was for an oxide operator sweeping in the 

burnout room as part of scrap recovery operations. Based on Table 7.7 of TBD-6000, the AM 

exposure for a scrap recovery operator was 6,170 dpm/m3, which is a daily weighted exposure. 

Since the exposure from sweeping was limited to 0.1 hr per day, it contributed about 1% of the 

operator’s daily exposure. It is apparent that the exposures from floor sweeping at the Hanford 

Melt Plant Building are captured by generic exposures from scrap recovery operations in TBD6000. 

5.3 OUTDOOR URANIUM PIT BURNING 

Information on exposures from outdoor pit burning of uranium to reduce the possibility of chip 

fires and promote scrap recovery is limited. Some outdoor burning results were reported for the 

Melt Plant Building at Hanford in Adley et al. 1952. Both an open hearth furnace and a graphite 

burner were located outside the Melt Plant Building. The open hearth furnace was used to burn 

crucible heels, floor sweepings, used gloves, and some material from a chip recovery process 

conducted in another building. The graphite burner was used for burning broken and discarded 

crucibles and stopper rods. Operations associated with graphite burner produced less dust than 

did operations associated with the open hearth furnace. The operation that resulted in the highest 

dust concentrations was shoveling the residue from the open hearth burning into barrels or 

buckets. In some cases, the burned material was sifted through a coarse screen before being 

loaded into a container. Adley et al. (1952) note that, while these operations were very dusty, 

they were of brief duration. They characterized the air concentrations for three operations: 

 Operation A – burning in open hearth furnace 

 Operation B – loading oxide from open hearth furnace into buckets and barrels 

 Operation C – graphite burning 

Air sampling results, including the average values, are summarized in Table 17 (Adley et al. 

1952, Table V). As noted above, Operation B was described in Adley as being of brief duration. 

If “brief duration” was one-half hour per day, then the weighted exposure for Operation B would 

be 4,800 dpm/m3

—a value less than the mean DWA of 6,200 dpm/m3 for a scrap recovery 

operator in TBD-6000. 

Table 17. Atmospheric Concentrations of Uranium at Hanford Melt Plant Outdoor 

Burning Operations 

Range of Uranium Concentrations AM Uranium Conc. Operation Number of 

Samples 10-5 μg/cm3 dpm/m3 dpm/m3

A 9 1.4 to 260 21 to 3,950 996 

B 3 3,930 to 6,370 59,700 to 96,800 76,800 

C 2 1.4 to 9.8 21 to 149 85.1 

Christofano and Harris (1960) provide some information on indoor burning of uranium as part 

of the scrap recovery process. These authors note that: 
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Scrap has been calcined to oxide in open trays and in multiple hearth calcining 

furnaces. Both methods led to similar occupational exposures of about 

1000 d/min/cu. m. 

This statement is a little confusing since other data included in Table 17 of Christofano and 

Harris (1960) describe the average exposure of furnace operators prior to 1952 as 3,000 dpm/m3

and 300 to 1,000 dpm/m3 after 1952. The average exposure of 3,000 dpm/m3 is less than the 

average exposure of 6,200 dpm/m3

 (DWA) for a generic scrap recovery operator from Table 7.7 

of TBD-6000. 

Kehoe et al. (1950) list dry burning as a safe disposal practice for uranium scrap. They state that: 

For a quantity not exceeding 5#, the scrap may be spread out on a steel plate in 

an open area and burned to oxide by the flame of an oxy-acetylene torch. The 

worker should be protected by a welders face shield and a metal fume respirator. 

The scrap should be raked to insure that all the metal goes to oxide. 

 

Some useful anecdotal information on the burning of uranium outdoors can be distilled from the 

U.S. military experience with depleted uranium armor-piercing projectiles. On July 1991, there 

was a large fire at the U.S. Army motor pool at Camp Doha, Kuwait, involving combat-ready 

vehicles and ammunition (Scherpelz et al. 2000). During the course of the fire, which lasted 

about 24 hours, many of the depleted uranium rounds were burned. 

With regard to exposures to depleted uranium from the fire plume, the authors stated that: 

 During the phase of the fire that produced the highest uranium air 

concentrations, the estimated average air concentration was 3.5 10-7g-U/m3 at 

the location of highest concentration. This concentration is well below the 

ACGIH limit of 2 10-4 g-U/m3 for workers exposed daily to uranium in air and 

represents a low concentration. This air concentration is also below the NRC 

limit for exposures of the general public to insoluble uranium. 

 The maximum radiological dose to a worker located in the position of highest air 

concentration for the full duration of the fire was calculated to be 0.000003 rem 

(CEDE), well below the annual limit of 0.10 rem for exposure by a member of the 

public. 

Considering exposures during clean-up, Scherpelz et al. concluded that: 

 During the recovery and cleanup activities, the estimated air concentrations 

ranged from 3.8 10-5 g/m3 to 4.2 10-4 g/m3

. These air concentrations, when 

averaged over the course of a year, are below the NRC limit when adjusted for 

particle size distribution for occupational exposure to airborne uranium, but they 

are greater than the NRC limits for exposure of the general public to uranium. 

These estimated air concentrations are greater than 2 10-4 g/m3

, which is the 

ACGIH limit for continuous exposure to uranium (the TWA), but are lower than 6 
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10-4 g/m3, the ACGIH limit for short-term exposures (TLV-STEL). The ACGIH 

air concentration limit was exceeded for only three weeks. 

 The estimated radiological dose received by the most highly exposed workers was 

0.065 rem. This dose is less than 0.1 rem, which is the NRC annual dose limit for 

individual members of the public. 

It was estimated that 465 kg of uranium oxides were produced during the fire and about 0.1% 

became airborne (http://www.gulflink.osd.mil/camp_doha_report_18may00.pdf). 

As noted above, the dose to a worker exposed to the highest air concentration for the full 

duration of the fire was 3E-06 rem. If we assume that the exposure was for 24 hours, then the 

exposure for a normal 8-hour work day would be 1E-06 rem and, adjusting this for the ratio of 

the specific activity of depleted uranium to natural uranium, the equivalent natural uranium 

exposure would be 1.7E-06 rem/day or 0.425 mrem/yr. From another perspective, the highest 

estimated uranium concentration of 3.5 10-7g-U/m3 for the Camp Doha, when adjusted to 

natural uranium, is only 0.6 dpm/m3

. This value is well within the exposure limits for scrap 

recovery, as defined in Table 7.7 of TBD-6000. 

Exposures during recovery and clean-up activities at Camp Doha were considerably higher due 

to resuspension of uranium oxide particles. The maximum estimated air concentration of 4.2 

10-4 g/m3 is equivalent to 640 dpm/m3, as compared to an average of 6,200 dpm/m3 (DWA) for 

an operator involved in uranium scrap recovery (Battelle 2011, Table 7.7). 

Based on the evidence presented here, it appears that exposures from open pit burning of 

uranium are encompassed by the generic scrap recovery operations explicitly covered in TBD6000. 

 

6.0 SUMMARY 

Over the past several months, SC&A was in a position to perform a very detailed analysis of 

TBD-6000 as it applied to many site profiles, Special Exposure Cohort (SEC) petition evaluation 

reports, and dose reconstructions. These analyses have been collected and reorganized into this 

report as a means to revisit SC&A’s original review of TBD-6000. This expanded and in-depth 

review confirms that TBD-6000 can be used to place a plausible upper bound on the airborne 

uranium exposures experienced by workers at Atomic Weapons Employer (AWE) facilities in 

the early years of the Manhattan Engineer District (MED) and Atomic Energy Commission 

(AEC) programs. However, care must be taken to insure that TBD-6000 data are properly 

applied. 

Specific conclusions include: 

 The use in TBD-6000 of a terminal settling velocity of 0.00075 m/s for 5 μm AMAD 

particles is supported by available experimental evidence and is claimant favorable. 
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NOTICE:

 The assumption that equilibrium between deposition and removal processes is reached in 

30 days as specified in TBD-6000 should be re-examined. The analyses presented here 

based on average settling rates in Main Bay of the Hanford Melt Plant Building indicate 

that 33–37 days are required to reach equilibrium based on 24 hr/day of settling and 40–

44 days based on 12.4 hr/day of settling. The 95th percentile of the 15 Main Bay samples 

is 69 days to reach equilibrium. Based on these calculations, the claimant-favorable 

approach would be to use a value of 70 days to achieve an equilibrium surface 

concentration where the rate of deposition equals the rate of removal. However, if the 

settling time for dust is 12.4 hr, the time to reach equilibrium would increase by 20% 

suggesting an upper bound of 84 days. 

 Comparison of generic air concentrations for various operations included in TBD-6000 

with similar operations at specific sites indicates that some site-specific DWA air 

concentrations exceed the GM values (and in a few cases the AM values) in TBD-6000. 

These high site-specific values are subsumed within the full distribution (i.e., lognormal 

with a GSD = 5) and comparable POCs result whether the lognormal distribution or the 

high site-specific value is used. 

 Chip fires during the machining of uranium were a common occurrence at AWE 

facilities. Two sources of information show that the air concentrations from machining 

operations where burning was observed do not exceed the generic values for a machining 

operator from Table 7.5 of TBD-6000. 

 The removal rate at equilibrium of uranium oxide particles deposited on surfaces was 

estimated to be 0.035/day. This rate is considerably higher than the removal rate of 

0.00067/day developed in ORAUT-OTIB-0070 (ORAUT 2012). The calculations 

presented here support the position that the OTIB-0070 approach regarding time to reach 

equilibrium is claimant favorable. 

 Measured dust concentrations from floor sweeping, when weighted for duration of the 

sweeping activity, were less than the generic DWA values for a scrap recovery operator 

from Table 7.7 of TBD-6000. Thus, floor sweeping is adequately covered by TBD-6000. 

 Outdoor burning of uranium can result in brief high dust concentrations associated with 

transfer of the ashes. If “brief duration” of exposure was one-half hour per day, then the 

weighted exposure for handling oxide dust would be 4,800 dpm/m3

—a value less than the 

mean DWA of 6,200 dpm/m3 for a scrap recovery operator in TBD-6000. Corroborating 

data from Christofano and Harris (1960) indicate indoor exposures 3,000 dpm/m3 from 

similar operations, and air concentrations from burning of depleted uranium in a military 

accident were about an order of magnitude lower than the TBD-6000 generic value. 

 There appear to be errors calculating the GMs in the tables in Section 7 of TBD-6000. 

NIOSH should check to be sure that the values are correct. 
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REFERENCES 

Adley, F.E., W.E. Gill, and R.H. Scott, 1952. Study of Atmospheric Contamination in the Melt 

Plant Building, USAEC report HW-233352 (Rev.), April 4, 1952. 

AEC (U.S. Atomic Energy Commission) 1948. Simonds Saw and Steel Occupational Exposure 

to Radioactive Dust – Visit of October 27, 1948. New York Operations Office. SRDB 10883. 

AEC 1949. Simonds Saw & Steel Co. Summary Report of Three Surveys (Oct. 27, 1948 – Feb. 

15, 1949), 1949. SRDB ID 11996, pp. 249–254. 

Allen 2009a. BATTELLE-TBD-6000 ISSUE 5 WHITE PAPER. Comparison to Adley and 

Simonds Saw Contamination Data. Prepared by Dave Allen, OCAS. October 9, 2009 

Allen 2009b. BATTELLE-TBD-6000 ISSUE 4 WHITE PAPER. Comparison to Adley Air 

Data also Simonds. Prepared by Dave Allen, OCAS. October 9, 2009 

Battelle 2011. Site Profiles for Atomic Weapons Employers that Worked Uranium Metals. 

Battelle-TBD-6000. Rev. 01. National Institute for Occupational Safety and Health (NIOSH); 

Cincinnati, Ohio; Division of Compensation Analysis and Support (DCAS); effective June 17, 2011; 

SRDB Ref ID: 101251

Bethlehem 1952. Bethlehem Steel – Sample Data Sheets – 1952, SRDB Ref ID #: 42589. pdf. 

pages 9-10. 

Christofano E., and W.B. Harris, 1960. “The Industrial Hygiene of Uranium Refining.” Env 

Health 1(5):74-96. 

Daniels, C.E., 1943. Project 9536 Metal Turnings-Fire Hazards, Correspondence to J.N. Tilley 

(DuPont) from C.E. Daniels (DuPont), August 27, 1943. SRBD Ref ID 116470. 

Flagan, R.C., and J.H. Seinfeld, 1988. Fundamentals of air pollution engineering. Chapter 5 – 

Aerosols. Prentice-Hall, Inc., Englewood Cliffs, New Jersey. ISBN 0-13-332537-7 

http://resolver.caltech.edu/CaltechBOOK:1988.001. 

Gerber, M.S., 1996. The Plutonium Production Story at the Hanford Site: Processes and 

Facilities History. WHC-MR-0521. Westinghouse Hanford Company. 

Harris, W.B., and I. Kingsley, 1959. “The Industrial Hygiene of Uranium Fabrication.” A.M.A. 

Archives of Industrial Health, Vol. 19, May 1959. pp 76-101. 

Heatherton 1952. Bethlehem Steel – Sample Data Sheets – 1952, Reference ID #: 3230 

ICRP (International Commission on Radiological Protection) 1994. Human Respiratory Tract 

Model for Radiological Protection (Oxford: Pergamon Press) ICRP Publication 66 (1994). 
Effective Date: 

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0 (Draft) 

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However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

NOTICE:

Kehoe, E.J., F.I. Brannigan, and M. Eisenbud, 1950. Fire protection precautions for handling 

uranium turnings, chips, borings, sawdust and powder. U.S. Atomic Energy Commission, New 

York Operations Office. March 1, 1950. SRDB Ref ID: 90891. 

NIOSH (National Institute for Occupational Safety and Health) 2010. Technical Basis 

Document: Basis for Development of an Exposure Matrix for Bethlehem Steel Corporation, 

Lackawanna, New York, Period of Operation: 1949–1952. DCAS-TKBS-0003, Rev. No. 1. 

November 30, 2010.

NIOSH (National Institute for Occupational Safety and Health) 2012. SEC Petition Evaluation 

Report SEC-00200. Joslyn Manufacturing. December 3, 2012.

ORAUT 2011. Site Profile for Simonds Saw and Steel, ORAUT-TKBS-0032, Rev. 01 PC-1, 

Oak Ridge Associated Universities Team, Cincinnati, Ohio. April, 18, 2011. 

ORAUT 2012. Dose Reconstruction during Residual Radiation Periods at Atomic Weapons 

Employer Facilities. ORAUT-OTIB-0070, Rev. 1, Oak Ridge Associated Universities Team, 

Cincinnati, Ohio. 

SC&A 2007. Draft Review of Battelle-TBD-6000, Site Profiles For Atomic Weapons Employers 

That Worked Uranium And Thorium Metals. Contract No. 200-2004-03805, Task Order No. 3. 

Scherpelz, R.I., R.J. Traub, J.G. Droppo, and M.A. Parkhurst, 2000. Depleted Uranium 

Exposures to Personnel Following the Camp Doha Fire, Kuwait, July 1991. Pacific Northwest 

National Laboratory. http://www.gulflink.osd.mil/camp_doha_summary18may00.pdf 

Strom, D. 2007. Default Assumptions and Methods for Atomic Weapons Employer Dose 

Reconstructions. Battelle-TIB-5000, Rev. 00. 

Whicker, J., 2007. Conversion from Physical to Aerodynamic Diameters for Radioactive 

Aerosols. Health Physics Meeting 2007. Prepared by Jeffrey Wicker, Los Alamos National 

Laboratory. 
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ATTACHMENT A: DERIVATION OF AIR CONCENTRATIONS AT 

HANFORD MELT PLANT BUILDING 

This attachment describes how air concentrations were estimated by NIOSH (Allen 2009b) for 

the Hanford Melt Plant Building based on data from Table IX in Adley et al. 1952. Table A-1 

summarizes the Adley data. 

Table A-1. DWA Exposures for Various Job Descriptions at the 

Hanford Melt Plant Building 

Job Title Weighted Daily Exposure (C x t) 

(μg-hr/cc) 

Avg Air Conc. 

(μg/cc) 

Furnace operator 1.59E-02 1.98E-03 

Furnace assistant 6.47E-03 8.09E-04 

Saw room operator 2.23E-02 2.79E-03 

Oxide operator 6.52E-02 8.16E-03 

Rod handler 2.02E-03 2.53E-04 

Rod receive unload 5.68E-03 7.10E-04 

Rod receive weigh 6.10E-04 7.63E-05 

Rod receive stack 2.40E-03 3.00E-04 

Autoclave operator 4.20E-04 5.25E-05 

The data in column 2 of Table A-1 are taken directly from Adley Table IX. The data in column 

3 are the column 2 data divided by 8 hours per work-day. 

From Table A-1, the GM and average inhalation air concentrations for the data set are 584 and 

1,680 μg/m3, respectively.
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ATTACHMENT B: IREP RUNS FOR HYPOTHETICAL OXIDE 

OPERATOR 

NIOSH-Interactive RadioEpidemiological Program 

Probability of Causation Results 

Uploaded file: LUNG; Type S, 11,112 dpm/d; (GM) (1-yr) DOL District Office: CL

Date of Run: 5/6/2013 NIOSH-IREP version: 5.7

Time of Run: 2:06:13 PM Analytica/ADE version: 3.0

NIOSH ID #: 123456 DOL Case No: 123-45-6789

Claimant Name: John Q. Doe

Claimant Cancer Diagnoses: 

Primary Cancer #1: N/A Date of Diagnosis: N/A 

Primary Cancer #2: N/A Date of Diagnosis: N/A

Primary Cancer #3: N/A Date of Diagnosis: N/A

Secondary Cancer #1: N/A Date of Diagnosis: N/A

Secondary Cancer #2: N/A Date of Diagnosis: N/A

Secondary Cancer #3: N/A Date of Diagnosis: N/A

Claimant Information Used In Probability of Causation Calculation: 

Gender: Male Race (skin cancer only): N/A

Birth Year: 1914 Year of Diagnosis: 1974

Cancer Model: Lung (162) Should alternate cancer model be run?: No

Smoking history (trachea, bronchus, or lung cancer only): Never smoked 

NIOSH-IREP Assumptions and Settings: 

User Defined Uncertainty Distribution: Lognormal(1,1) 

Number of Iterations: 2,000 Random Number Seed: 99
Effective Date: 

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General Exposure Information: 

# Exp. Year Organ Dose (cSv) Exp. Rate 

1 1948 Lognormal (127, 5) chronic 

2 1949 Lognormal (41.1, 5) chronic 

3 1950 Lognormal (20.6, 5) chronic 

4 1951 Lognormal (15, 5) chronic 

5 1952 Lognormal (11.1, 5) chronic 

6 1953 Lognormal (8.47, 5) chronic 

7 1954 Lognormal (6.62, 5) chronic 

8 1955 Lognormal (5.31, 5) chronic 

9 1956 Lognormal (4.38, 5) chronic 

10 1957 Lognormal (3.68, 5) chronic 

11 1958 Lognormal (3.16, 5) chronic 

12 1959 Lognormal (2.77, 5) chronic 

13 1960 Lognormal (2.46, 5) chronic 

14 1961 Lognormal (2.2, 5) chronic 

15 1962 Lognormal (1.98, 5) chronic 

16 1963 Lognormal (1.8, 5) chronic 

17 1964 Lognormal (1.65, 5) chronic 

18 1965 Lognormal (1.51, 5) chronic 

19 1966 Lognormal (1.39, 5) chronic 

20 1967 Lognormal (1.28, 5) chronic 

21 1968 Lognormal (1.19, 5) chronic 

22 1969 Lognormal (1.1, 5) chronic 

23 1970 Lognormal (1.01, 5) chronic 

24 1971 Lognormal (0.939, 5) chronic 

25 1972 Lognormal (0.872, 5) chronic 

26 1973 Lognormal (0.806, 5) chronic 

27 1974 Lognormal (0.326, 5) chronic 

Radiation Type 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

alpha 

Radon Exposure Information: 

 N/A (applies only to cases of Lung Cancer with Radon Exposures) 

Probability of Causation (PC) * 

 1st percentile 8.17 % 

 5th percentile 16.46 % 

 50th percentile 67.76 % 

 95th 

 99th 

percentile 95.94 % 

percentile 98.63 % 

NIOSH-Interactive RadioEpidemiological Program 
Effective Date: 

May 13, 2013 

Revision No. 

0 (Draft) 

Document No.

Supplementary Comments on TBD-6000 Rev. 01 

Page No. 

33 of 34 

NOTICE: This report has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

Probability of Causation Results 

Uploaded file: LUNG; Type S, 81,534 dpm/d; (Constant) (1-yr) DOL District Office: CL

Date of Run: 5/6/2013 NIOSH-IREP version: 5.7

Time of Run: 2:30:21 PM Analytica/ADE version: 3.0

NIOSH ID #: 123456 DOL Case No: 123-45-6789

Claimant Name: John Q. Doe

Claimant Cancer Diagnoses: 

Primary Cancer #1: N/A Date of Diagnosis: N/A 

Primary Cancer #2: N/A Date of Diagnosis: N/A

Primary Cancer #3: N/A Date of Diagnosis: N/A

Secondary Cancer #1: N/A Date of Diagnosis: N/A

Secondary Cancer #2: N/A Date of Diagnosis: N/A

Secondary Cancer #3: N/A Date of Diagnosis: N/A

Claimant Information Used In Probability of Causation Calculation: 

Gender: Male Race (skin cancer only): N/A

Birth Year: 1914 Year of Diagnosis: 1974

Cancer Model: Lung (162) Should alternate cancer model be run?: No

Smoking history (trachea, bronchus, or lung cancer only): Never smoked 

NIOSH-IREP Assumptions and Settings: 

User Defined Uncertainty Distribution: Lognormal(1,1) 

Number of Iterations: 2,000 Random Number Seed: 99

General Exposure Information: 

# Exp. Year Organ Dose (cSv) Exp. Rate Radiation Type 

1 1948 Constant (935) chronic alpha 

2 1949 Constant (301) chronic alpha 

3 1950 Constant (151) chronic alpha 

4 1951 Constant (110) chronic alpha 

5 1952 Constant (81.8) chronic alpha 

6 1953 Constant (62.2) chronic alpha 

7 1954 Constant (48.6) chronic alpha 

8 1955 Constant (39) chronic alpha 
Effective Date: 

May 13, 2013 

Revision No. 

0 (Draft) 

Document No.

Supplementary Comments on TBD-6000 Rev. 01 

Page No. 

34 of 34 

 This report has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

9 1956 Constant (32.2) chronic alpha 

10 1957 Constant (27) chronic alpha 

11 1958 Constant (23.2) chronic alpha 

12 1959 Constant (20.3) chronic alpha 

13 1960 Constant (18) chronic alpha 

14 1961 Constant (16.1) chronic alpha 

15 1962 Constant (14.6) chronic alpha 

16 1963 Constant (13.2) chronic alpha 

17 1964 Constant (12.1) chronic alpha 

18 1965 Constant (11.1) chronic alpha 

19 1966 Constant (10.2) chronic alpha 

20 1967 Constant (9.42) chronic alpha 

21 1968 Constant (8.72) chronic alpha 

22 1969 Constant (8.04) chronic alpha 

23 1970 Constant (7.44) chronic alpha 

24 1971 Constant (6.89) chronic alpha 

25 1972 Constant (6.4) chronic alpha 

26 1973 Constant (5.91) chronic alpha 

27 1974 Constant (2.4) chronic alpha 

Radon Exposure Information: 

 N/A (applies only to cases of Lung Cancer with Radon Exposures) 

Probability of Causation (PC) * 

 1st percentile 23.66 % 

 5th percentile 46.21 % 

 50th percentile 86.82 % 

 95th percentile 97.77 % 

 99th percentile 99.01 % 

 

 

NOTICE: