Draft 

REVIEW OF INTERNAL EXPOSURES TO URANIUM AT THE 

KANSAS CITY PLANT USING TBD-6000 AND 

ORAUT-OTIB-0070 AS SURROGATE DATA 

Contract No. 211-2014-58081

Prepared by 

John Mauro, PhD, CHP 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, Virginia 22182 

Saliant, Inc. 

5579 Catholic Church Road 

Jefferson, Maryland 21755 

July 2014 

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 pre-decisional and has not been reviewed by the Board for 

factual accuracy or applicability within the requirements of 42 CFR 82. 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.
Effective Date:

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0 – Draft

Document Description: White Paper:

Internal Exposures to Uranium at KCP

Page No.

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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 

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S. Cohen & Associates:

Technical Support for the Advisory Board on

Radiation & Worker Health Review of

NIOSH Dose Reconstruction Program

Document No.:

Internal Exposures to 

Uranium at KCP

Effective Date: 

Draft – July 24, 2014

Revision No.:

0 (Draft)

REVIEW OF INTERNAL EXPOSURES TO 

URANIUM AT THE KANSAS CITY PLANT 

USING TBD-6000 AND ORAUT-OTIB-0070 AS 

SURROGATE DATA

Page 2 of 17

Task Manager:

_____________________________ Date: ___________

Joseph Fitzgerald

Supersedes:

N/A

Project Manager:

_____________________________ Date: ___________

John Stiver, MS, CHP

Reviewers:

 Joseph Fitzgerald

 Arjun Makhijani

 John Stiver

Record of Revisions

Revision 

Number

Effective 

Date Description of Revision

0 (Draft) 07/24/2014 Initial issue
Effective Date:

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Internal Exposures to Uranium at KCP

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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. 

TABLE OF CONTENTS 

Introduction ......................................................................................................................................4

Evaluation ........................................................................................................................................7

Airborne Uranium Dust Loadings during Machining Operations .......................................7

Airborne Dust Loadings and Exposures Associated with the Residual Period 

following the Termination of Uranium Machining Operations in 1955 ................13

Conclusions ....................................................................................................................................15

References ......................................................................................................................................16

LIST OF EXHIBITS 

Exhibit A. Reproduction of Table 6-2 from NIOSH’s KCP SEC PER ..........................................5

Exhibit B. Reproduction of Table 6-3 from NIOSH’s KCP SEC PER ..........................................6

Exhibit C. Reproduction of Table 5 – Machining Operations ......................................................10

Exhibit D. Reproduction of Table 6 – Abrasive Operations .........................................................10

Exhibit E. Plot of 1958 Air Sampling Data for KCP Main Manufacturing Building ...................14

Exhibit F. Summary Table of 1958 Air Sampling Data for KCP .................................................15
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INTRODUCTION 

The Special Exposure Cohort (SEC) Petition Evaluation Report (PER), SEC-00210, for the 

Kansas City Plant (KCP) (January 7, 2014) presents a detailed description of the uranium 

operations that took place at the KCP and the methods that NIOSH plans to use to reconstruct the 

internal exposure to workers due to these operations. This white paper presents a review of the 

information provided in the SEC PER and the supporting site profile (ORAUT 2006) and 

SC&A’s position regarding the degree to which internal doses to workers at the KCP from 

uranium can be reconstructed in a scientifically sound and claimant-favorable manner using 

TBD-6000 (Battelle 2011) and ORAUT-OTIB-0070 (ORAUT 2012) protocols as a surrogate for 

time periods with limited air sampling data and workers with limited bioassay data. This report 

specifically addresses uranium machining operations that took place from 1950 to 1955 and the 

associated residual period from March 1, 1955, to 1958; in 1958, other uranium operations and 

substantial air sampling and bioassay data became available. 

Detailed descriptions of the uranium handling operations that took place at the KCP are 

described in several sections of the SEC PER. Section 5.1.2 states the following: 

NIOSH has information that KCP workers inspected and assembled uranium 

components, machined uranium slugs, and handled uranium billets and ingots at 

KCP in the early 1950s. Starting in May 1950 and continuing to February 1955, 

uranium components were inspected and assembled in Department 3A (KCP, 

1950–1963). In February 1951, KCP set up a machine shop to produce 1,000 

slugs per day to fuel AEC production reactors at the Savannah River Site in South 

Carolina, and Argonne National Laboratory near Chicago, Illinois. KCP 

received some of the 10-foot long uranium rod stock for this work from the 

Lackawanna Test Site in New York. Forty-five thousand (45,000) slugs were 

produced for the initial order. Ongoing work to produce 5-tons per month was 

also scheduled. The work was performed in the Main Manufacturing Building in 

Department 49X, also known as Area X. This area was specifically prepared for 

this work: a smooth finished concrete floor was laid and painted, steel panel walls 

were erected, an adjacent storeroom was prepared, and the entire area was 

cleaned and painted. The equipment used to make slugs in this area included: an 

8'' Springfield bench lathe; a Fay Automatic lathe; a Schauer air collet machine; 

a power cut-off saw; and four Gisholt turret lathes (see Figure 5-3). Work was 

performed during two shifts utilizing machine operators (14), inspectors (3), an 

accountability officer, and a packaging man (Mahaffey, 1952; Paine, 1951). 

Additional description of the uranium machining operations, including the machining of billets 

and ingots, is provided in Section 5.2.1. As will be discussed later in this report, these types of 

uranium machining operations were common and extensively studied by the Health and Safety 

Laboratory (HASL) at about the same time these operations were taking place at the KCP. It is 

these investigations that helped establish the technical underpinnings of TBD-6000, which, as 

will be discussed later, is used as a surrogate for reconstructing exposures to uranium to KCP 

workers during this time period. It is noteworthy that the uranium machining operations appear 

to be limited to lathe operations and power saw cutting of natural uranium metal slugs. 
Effective Date:

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

Section 5.2.1.1 provides additional information on the types of exposures the uranium machining 

operators experienced, emphasizing that the uranium was natural uranium. However, 

Section 5.2.1.2 explains that substantial quantities of depleted uranium (DU) were machined 

from April 1958 to 1971. Also, uranium oxide powder with an AMAD (activity median 

aerodynamic diameter) of 1.175 was handled at the facility in the 1960s, but it is not apparent 

exactly what was done with the powder. 

On page 26, this section concludes with a description of another uranium process performed in 

1997, where a new program was initiated: 

DU metal was reduced in size and shape by an electrochemical process that 

involves the placement of DU metal in an acid bath. The parts are rinsed with 

water and dried before handling. Because the uranium does not become volatile 

during the electrochemical process, remaining in the acid solution, there is 

minimal personnel internal dose hazard with this process. There is also no 

removable contamination with this process (ORAUT-TKBS-0031). 

Given this as background information on the different types of uranium operations that took 

place at the facility, Section 6.1 of the SEC PER provides a description of the data that are 

available for reconstructing internal exposures to uranium. On page 31, the section quotes an 

AEC survey in 1952 (Safety Survey 1952) that states: 

Atmospheric dust analysis and general observation within the Machining of 

Uranium Metal Area indicated that personnel are being properly safeguarded. 

The dust count in the lathe area during cutting operations was well below any 

limit wherein the toxicity might be considered. Some smoke and oxides were 

noticed, but the hood ventilation appeared to be adequate. Assembly Area dust 

samples were negative and the neatness of the area was impressive. 

The section also states that the routine air sampling monitoring was performed from 1958 to 

1971. The following table extracted from page 32 of the SEC PER presents a summary of the 

data. Note that these data are part of the ongoing review of the KCP site profile and SEC PER. 

Exhibit A. Reproduction of Table 6-2 from NIOSH’s KCP SEC PER

Table 6-2: Statistical Parameters of Measured DU in KCP Workplace Air

(a),(b)

for 1958–1970

KCP Measured Results

(a) Lognormal Fit

Air Concentration

Year

No. of

Measurements

Mean

(μCi/cm

3

)

Maximum

(μCi/cm

3

)

Median

(μCi/cm

3

)

95%

(μCi/cm

3

) GSD

1958 22 7.18E-12 4.90E-11 4.01E-13 1.74E-10 4.02E+01

1959 27 8.82E-13 1.22E-11 2.89E-13 2.53E-12 3.74E+00

1960 33 1.32E-12 1.50E-11 3.41E-13 3.94E-12 4.43E+00

1961 31 1.00E-12 2.04E-11 1.97E-13 1.52E-12 3.46E+00

1962 31 7.73E-13 1.13E-11 2.50E-13 2.03E-12 3.58E+00

1963 31 1.25E-12 1.63E-11 2.47E-13 1.90E-12 3.46E+00

1964 31 2.21E-12 3.90E-11 3.91E-13 2.98E-12 3.44E+00

1965 31 1.99E-13 8.70E-13 1.05E-13 8.02E-13 3.45E+00

1966 23 7.01E-13 6.24E-12 2.00E-13 2.00E-12 4.06E+00
Effective Date:

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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. 

Exhibit A. Reproduction of Table 6-2 from NIOSH’s KCP SEC PER

Table 6-2: Statistical Parameters of Measured DU in KCP Workplace Air

(a),(b)

for 1958–1970

KCP Measured Results

(a) Lognormal Fit

Air Concentration

Year

No. of

Measurements

Mean

(μCi/cm

3

)

Maximum

(μCi/cm

3

)

Median

(μCi/cm

3

)

95%

(μCi/cm

3

) GSD

1967 22 1.40E-12 1.30E-11 5.70E-13 3.12E-12 2.81E+00

1968 19 1.21E-12 9.88E-12 2.31E-13 3.47E-12 5.19E+00

1969 19 1.88E-11 8.55E-11 3.88E-12 1.42E-10 8.92E+00

1970 19 7.32E-14 5.91E-13 4.02E-14 1.98E-13 2.64E+00

Average 1958-1970 2.85E-12 2.15E-11 5.49E-13 2.62E-11

Source: This table is a slightly modified version of Table 11 from ORAUT-TKBS-0031.

(a) All departments.

(b) Based on maximum measured KCP workplace airborne uranium concentrations at several monitoring locations. 

The section also describes the urine bioassay program and minimum detectable levels (MDLs) 

performed at the time that DU powder was handled and refers the reader to each worker’s 

bioassay records. The following table, extracted directly from page 34 of the SEC PER, provides 

a summary of the bioassay results (these data are also part of the KCP site profile and SEC PER 

review): 

Exhibit B. Reproduction of Table 6-3 from NIOSH’s KCP SEC PER

Table 6-3: Statistical Parameters of Recorded DU in Urine for 1959–1971(a)

Year

Recorded Annual Urine

Concentration

(b) Lognormal Fit Chronic intakes (pCi/d)

(c)

No. of 

Workers 

Reported

Concentration (μg/L) Concentration (μg/L)

Mean Maximum Median GSD 5

th Median 95th

1959 214 4.125 52.60 2.642 2.675 1.05E+02 6.42E+02 3.92E+03

1960 281 36.58 140. 19.53 3.813 7.79E+02 4.75E+03 2.89E+04

1961 123 51.40 192.1 37.44 2.402 1.49E+03 9.10E+03 5.55E+04

1962 148 4.327 15.75 3.162 2.508 1.26E+02 7.69E+02 4.69E+03

1963 211 10.96 72.00 7.564 2.532 3.02E+02 1.84E+03 1.12E+04

1964 219 5.627 78.38 3.888 2.431 1.55E+02 9.46E+02 5.76E+03

1965 175 9.572 38.00 5.583 3.422 2.23E+02 1.36E+03 8.27E+03

1966 223 6.432 45.05 4.214 2.640 1.68E+02 1.02E+03 6.24E+03

1967 159 5.438 21.50 3.574 2.713 1.43E+02 8.69E+02 5.30E+03

1968 11 6.055 6.600 6.052 1.029 2.42E+02 1.47E+03 8.97E+03

1969 <10 0.15 0.150 0.150 1.000 5.99E+00 3.65E+01 2.22E+02

1970 59 11.64 45.00 7.576 2.686 3.02E+02 1.84E+03 1.12E+04

1971 47 0.03596 0.1000 0.02993 1.903 1.19E+00 7.28E+00 4.44E+01

ALL 1,871 14.1 192.1 5.5 4.7

Source: This table is a slightly modified version of Table 12 in ORAUT-TKBS-0031.

(a) All bioassay measurements.

(b) The recorded annual sum of urine concentration is the sum of all bioassay results for the year. There is one sum for each 

person-year record. The listed statistics are based on the analysis of the data, which are the sums of all bioassay data for every 

person for that year. 

(c) Chronic intakes that produce the urinary excretion per day on the 365th day of intakes corresponding to the median excretion 

from the lognormal fit and 5

th and 95th percentile intakes using a GSD of 3. Assumes 5-μm AMAD particle size and absorption 

Type S; intakes for 1-μm AMAD particle size, 10.97 g/cm3 density, and absorption Type S are smaller.
Effective Date:

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

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Table 6-4 of the SEC PER also provides a summary of bioassay data by worker category, where 

the concentration of uranium in urine ranged from below the MDL to 14.08 μg/L with an 

average of 9.44 μg/L. These data and the associated MDLs are not discussed here, but they are 

being addressed as part of the KCP site profile and SEC PER review. 

Given these data, Section 7.1.1 discusses the pedigree of the data and the approach NIOSH has 

adopted to assign bounding internal doses to workers from handling uranium at the facility. As 

may be noted, there is a considerable body of air sampling and bioassay data beginning in 1958, 

but the data are limited for the time period from May 1, 1950, through February 28, 1955. In 

theory, the air sampling and bioassay data summarized in Tables 6-2 and 6-3 can be used to 

reconstruct internal exposures to uranium workers using worker-specific data or through the 

development of claimant-favorable coworker models. The degree to which internal doses to 

uranium can be reliably reconstructed for these time periods and using these data sources are 

being addressed as part of the overall review of the KCP site profile and SEC PER review. 

EVALUATION 

This section focuses on the use of TBD-6000 as a scientifically sound and claimant-favorable set 

of protocols, data, and assumptions to reconstruct the internal uranium doses to KCP workers 

during those time periods where air sampling and bioassay data are limited. It should be noted 

that the use of TBD-6000 as one of the methods adopted by NIOSH to reconstruct internal 

exposures to uranium at the KCP is not addressed in the KCP site profile. This review also 

addresses the use of ORAUT-OTIB-0070 as the basis for reconstructing the doses to workers 

during the residual period following the termination of the uranium machining operations period, 

which took place during the period 1950 to 1955. 

Airborne Uranium Dust Loadings during Machining Operations 

Section 7.2.3.1, Natural Uranium Operations from May 1, 1950, through February 28, 1955, is 

where the SEC PER begins to describe the use of TBD-6000 to reconstruct internal doses to 

uranium for that time period. It should be noted that the machining operations as described and 

referenced in the SEC PER are more detailed than we have seen for most other Atomic Weapons 

Employer (AWE) operations, which allows us to better evaluate the degree to which TBD-6000, 

including its supporting source document, Harris and Kingsley 1959 (see also Harris 1951 and 

Harris and Kingsley 1958), can be used as a surrogate for the early uranium operations at KCP. 

The endnote of Harris and Kingsley describes how the data and other descriptive information 

provided in the report were compiled: 

The investigations which resulted in the data contained in this report were 

performed mainly by members of the Industrial Hygiene Branch of the Health and 

Safety Laboratory, especially by Paul Klevin, A.J. Breslin, and Martin Weinstein. 

Assistance was provided by the analytical branch of the laboratory in processing 

the enormous number of samples involved in these studies. 

Assistance was also provided by the following persons and industrial concerns: 

Dr. Joseph Quigley and Mr. R.C. Heatherton and the Feed Materials Processing 
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Center, Fernald Ohio; Mr. Mont Mason and the Mallinckrodt Chemical Works; 

Simonds Saw and Steel; Bridgeport Brass Company; and Sylvania-Corning 

Nuclear. Most photographs were supplied by the Fernald plant.

At the time, the HASL was one of the foremost radiological laboratories in the world. Because 

of the importance of this report, SC&A and NIOSH have been assigned on numerous occasions 

to further investigate and validate the completeness and reliability of the data (see SC&A 2013 

and 2007; also see Allen 2009a and 2009b), and it is SC&A’s position that the Harris and 

Kingsley report establishes a scientifically sound basis upon which to build a matrix of coworker 

models (as was done in TBD-6000) for reconstructing internal exposures to workers involved in 

the handling of uranium during the late 1940s and early 1950s, a time when the Manhattan 

Engineering District (MED) and the Atomic Energy Commission (AEC) relied heavily on 

selected private industries to support the weapons complex before uranium handling facilities, 

such as those at Fernald and Hanford, became available. In fact, it was the experience gained at 

these AWE facilities that established the scientific and engineering underpinning for uranium 

handling employed by the weapons complex. Notwithstanding the level of excellence achieved 

by the Harris and Kingsley report, SC&A believes that care must be taken in each application of 

TBD-6000 (and by reference, Harris and Kingsley) to any particular uranium handling operation, 

such as the operations that took place at KCP during the early 1950s.

The SEC PER explains that NIOSH selected the airborne uranium dust loading for the job 

category “operator” from Table 7.5 of TBD-6000, specifically 5,480 dpm/m3, for use as 

surrogate uranium air concentration for early uranium operations at KCP. Inspection of 

Table 7.5 reveals that a uranium dust loading of 5,480 dpm/m3represents the highest geometric 

mean (GM) dust loading concentration among the 20 different categories of uranium machining 

operations addressed in TBD-6000. In addition, this dust loading is characterized as the daily 

weighted average (DWA) for centerless grinding operations, which is recognized in the 

supporting documentation provided in Harris and Kingsley (1959) as the operation with the 

highest airborne dust loadings. Table 7.5 of TBD-6000 also provides the range of measured air 

dust loading concentrations for centerless grinding as 5,000-6,000 dpm/m3. However, it should 

be pointed out that the image of the lathe provided in Figure 5-3 of the SEC PER is a turret lathe, 

and it appears that most of the uranium machining operations at KCP involved lathes, as opposed 

to centerless grinding. A turret lathe is designed to remove metal by moving the rotating work

piece against a cutting tool which produces metal chips (not unlike the shavings from planing a 

piece of wood). In centerless grinding, an abrasive cutting wheel rotates against the work piece 

and removes metal by an abrasive action (not unlike sandpaper). The residues and uranium dust 

from centerless grinding involve much larger quantities of finer particles of uranium than a lathe.

Hence, from the perspective of TBD-6000, NIOSH certainly selected the highest dust loading 

among the various categories of uranium machining operations that took place in the early to mid 

1950s.

Page 101 of Harris and Kingsley (1959) describes uranium machining operations, explaining that 

uranium fires can occur frequently during machining unless a few rules are followed, including: 

(1) Applying 8- to 15-gal/minute of coolant to the uranium undergoing machining, using a 

variety of different types of oils. As indicated on page 41 of the SEC PER, Texaco 
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soluble oil “C” was used, which is one of the coolant types recommended by Harris and 

Kingsley.

(2) Low cutting rates; e.g., below 100 surface feet per minute.

(3) Carbide-tipped tools. 

(4) Use a chip breaker, which enhances coolant quenching.

The report goes on to describe other good practices that would help to reduce airborne uranium 

dust loading and fires and specifically addresses good practices associated with lathe operations. 

Page 102 of Harris and Kingsley goes on to describe the range of airborne uranium dust 

breathing zone concentrations observed during a variety of lathe operating conditions, ranging 

from 3 to 90 dpm/m3 with optimal operating speeds but no ventilation. At higher than optimum 

cutting speeds (e.g., 200 ft/min), the breathing zone dust concentrations were as high as 1,750 

dpm/m3. However, with appropriate local ventilation, the dust loadings were reduced to <1 

dpm/m3. Figure 5 in Harris and Kingsley (1959) shows a canopy hood over a turret lathe that 

was effective in reducing dust to the indicated levels.

Our review of the supporting documentation for lathe operations at the KCP reveals that, in 

addition to the abundant use of cooling oil and ventilation, the fastest rpm stated was 402 rpm 

(Stowers 1951a; Williams 1951) and the smallest finished piece diameter was 0.750 in (Stowers 

1951a; Stowers 1951b; Stowers 1951c); therefore, (0.750 in) × π × (1 ft/12 in) × (402 rev/min) ≈ 

78.9 surface feet per minute. Also, the following carbide-tipped cutting tools were used 

(Stowers 1951a; Paine 1951; Mahaffey 1952):

 Garmet CA-1

 Kennametal K3H

 Kennametal K6

 Vascoloy

Finally, a safety survey was conducted at KCP (Johnson 1952). Attachment II of the Johnson 

memo provided the safety survey report of W.H. Kingsley. With respect to the machining of 

uranium metal, Kingsley stated the following:

Atmospheric dust analyses and general observation within the subject area 

indicated that personnel are being properly safeguarded. The dust count in the 

lathe area during cutting operations was well below any limit wherein toxicity 

might be considered. Some smoke and oxides were noticed, but hood ventilation 

appeared to be adequate.

I should also like to comment here on the efficiency of the film badge system 

throughout the areas visited. It was quite evident that the contractor personnel 

have the problem well in hand. The 3A-Assembly Area dust analyses were 

negative and the neatness of the area was impressive.

This information would seem to indicate that the lathe operations employed many of the 

techniques and systems that would help to reduce airborne dust loading of uranium. Hence, the 
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dust loading at the KCP during uranium machining operations in 1950 to 1955 likely was

associated with dust loading that was within the bounding values for lathe operations as reported 

by Harris and Kingsley and adopted in TBD-6000. In addition, as discussed below, NIOSH used 

bounding dust loadings that are applicable to centerless grinding, which adds additional 

conservatism to the analysis.

Page 104 of Harris and Kingsley provides a fairly detailed description of a centerless grinder and 

its potential to generate airborne uranium dust. The section explains that a centerless grinder 

needs to be enclosed as completely as possible in a leak-proof head and ventilated with a velocity 

through all openings of 500 feet/min; without such controls, breathing zone concentrations as 

high as 13,000 dpm/m3have been observed.

Tables 5 and 6 of Harris and Kingsley summarize the results of their comprehensive 

investigations, as follows:

Exhibit C. Reproduction of Table 5 – Machining Operations

(Daily Weighted Averages in d/m/M3)

Operator No. vent Vent

Automatic lathe 200–300 30–70

*Turret lathe 150 40–50

*Facing (each) 100 –

*Cutoff (each) 100 20–30

*Milling (each) 100 20–30

*Slotting (each) 100 20–30

Drill 20 10

*Radius cutting 100–300 30

Milling 40 –

Shaping <10 –

Planning <10 –

*Values are for normal operations. With speeds less than 100 surface feet and adequate cooling, all results are less 

than 10 d/m/M3.

Exhibit D. Reproduction of Table 6 – Abrasive Operations

(Daily Averages d/m/M3)

Operator No Vent Vent

Cut-off –* <1

Surface grinder 2,000–5000 50–200

Portable grinder 400 50–200

Belt sander 3000 <10

Centerless grinder 5,000–6,000 50–300

*Never sampled, but very high.

It is apparent that by adopting a dust loading of 5,430 dpm/m3as the DWA uranium dust loading 

for uranium workers at KCP for the early 1950s, NIOSH is using the dust loading associated 

with a centerless grinder, the highest dust loading among all of the uranium machining and 

handling operations, and assumed no special ventilation controls. In fact, the KCP operations at 

the time appear to have primarily used various types of lathes. The implications are that the 

surrogate data adopted by NIOSH for these exposures is likely to be overestimated by at least a 

factor of 10. In fact, NIOSH would have been on solid scientific ground if it used the lathe 
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operation data as the basis for dose reconstruction at the KCP. However, by using centerless 

grinding surrogate data, NIOSH is assured of meeting the surrogate data criteria discussed 

below.

In many reports of this type prepared by SC&A, we often conclude with a section that evaluates 

the surrogate data employed by NIOSH against the five surrogate data criteria adopted by the 

Advisory Board on Radiation and Worker Health (ABRWH 2010). The following presents that 

comparison.

Based on the information presented in this report, one can make a determination regarding 

whether or not the use of TBD-6000 surrogate data for the uranium machining operations that 

took place at the KCP in the early 1950s meets the Board criteria for surrogate data, as follows:

(1) Hierarchy of Data. It should be assumed that the usual hierarchy of data would 

apply to dose reconstructions for that site (Individual worker monitoring data 

followed by co-worker data followed by workplace monitoring data such as area 

sampling followed by process and source term data.) This hierarchy should be 

considered when evaluating the potential use of surrogate data. Surrogate data 

should only be used to replace data if the surrogate data have some distinct 

advantages over the available data and then only after the appropriate 

adjustments have been made to reflect the uncertainty inherent in this 

substitution.

There was limited air sampling or bioassay data available during the uranium machining 

operations at KCP during the early 1950s. In terms of hierarchy of data, generic air sampling 

data from TBD-6000 site was appropriately substituted for limited air sampling and bioassay 

data.

(2) Exclusivity Constraints. In many cases, surrogate data are used to supplement 

the available monitoring data from a site. In those cases, the surrogate data is

[sic] usually used to justify certain assumptions about the distribution or range of 

possible exposures or assumptions about the source terms. In those cases, no 

special justification is necessary beyond the usual scientific evaluation. This is 

akin to the Type II use described above. However, in other situations, there are 

no or very little monitoring data available. In those cases, the use of the 

surrogate data as the basis for individual dose reconstruction would need to be 

stringently justified. This judgment needs to take into account not only the 

amount of surrogate data being relied on relative to data from the site but also 

the quality and completeness of that surrogate data.

The fact that TBD-6000 has been carefully vetted by a Work Group of the ABRWH is indicative 

of stringent justification of that document as a source of surrogate data. The selected surrogate 

data from TBD-6000 were based on the sampling work of HASL, which is regarded to be of high 

quality. The TBD-6000 data are composites from a number of sites and were selected from the 

source document (Harris and Kingsley 1959) using the most conservative groups of 
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measurements. Consequently, the quality and quantity of the data used should satisfy this 

criterion.

(3) Site or Process Similarities. One of the key criteria for judging the 

appropriateness of the use of surrogate data would be the similarities between the 

site (or sites) where the data were generated and the site where the surrogate 

data are being utilized. The application of any surrogate data to an individual 

dose reconstruction at a site should include a careful review of the rationale for 

utilizing that source of data.

The uranium machining operations at the KCP during the early 1950s are thoroughly described 

in the SEC PER, and it is clear that those operations fall within the scope of machining 

operations described in TBD-6000 and also its supporting documentation provided in Harris and 

Kingsley (1959). In fact, if anything, the surrogate data adopted by NIOSH likely overestimate

the inhalation exposures to uranium that might have occurred at the KCP during the early 1950s, 

because it appears that most machining operations involved the use of lathes, while NIOSH 

elected to use TBD-6000 data for centerless grinding as the surrogate for all machining 

operations, which likely overestimates the exposures. By adopting this strategy, NIOSH ensures 

that Criterion 2 is satisfied. As may be noted, a delicate balance must be struck between the 

requirements of Criterion 2, Exclusivity Constraints, and Criterion 5, Plausibility. We believe 

that NIOSH has struck this balance, with greater emphasis given to meeting Criterion 2.

(4) Temporal Considerations. Consideration also needs to be given to the period in 

question, since working conditions and processes varied in different periods. 

Surrogate data should belong in the same general period as the period for which 

doses are sought to be reconstructed unless it can be demonstrated that the 

working conditions, procedures, monitoring methods, and (perhaps) legal 

requirements were comparable to the period in question.

The data gathered by the HASL and reported in Harris and Kingsley (1959) and used as the basis 

for TBD-6000, were collected at time periods that were contemporaneous with the KCP 

operations in the early 1950s. Hence, this criterion is satisfied.

(5) Plausibility. The plausibility criterion equates plausibility with the 

reasonableness of the assumptions made regarding surrogate data. The 

plausibility determination should address issues of:

 Scientific plausibility. Are the assumed models (e.g., bioassay, concentration 

gradients) scientifically appropriate? Have the models been validated (where 

feasible) using actual monitoring data collected in a similar situation?

 Workplace plausibility. Are the assumed processes and procedures (including 

monitoring) plausible for the facility in question? Have all of the factors that 

could significantly impact exposure been taken into account? Is adequate 

information available about the facility in order to be able to make a fair 

assessment?
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With regard to scientific plausibility, as described previously, internal exposures were based on 

actual monitoring data collected under similar situations by a respected measurement laboratory. 

With regard to workplace plausibility, we described in Section 2.1 that the processes and 

procedures that underlie the TBD-6000 data are generally comparable and likely more 

conservative than the processes used at the KCP in the early 1950s. We have also noted that the 

methodology used in TBD-6000 was to select from air concentrations measured for several job 

descriptions. The particular operation (i.e., machining) that resulted in the highest exposure was 

selected and applied to all the operators involved in the uranium machining operation. Given 

this methodology, it is reasonable to assume all of the factors that could significantly impact 

exposure have been taken into account.

It is our opinion that use of surrogate data from TBD-6000 for dose reconstruction at the KCP 

during uranium machining operations in the early 1950s satisfies the ABRWH criteria.

Airborne Dust Loadings and Exposures Associated with the Residual Period following the 

Termination of Uranium Machining Operations in 1955 

Section 7.2.3.1 describes the methods used to reconstruct internal exposures due to residual 

uranium deposited on surfaces following the termination of uranium machining operations in 

1955. The section refers to TBD-6000 as the basis for the approach. However, it appears that

NIOSH actually used the protocols described in ORAUT-OTIB-0070, which SC&A has 

previously reviewed and found to be scientifically sound and claimant favorable. The following 

is a description of the protocol used and any comments SC&A has regarding that protocol as

applied to the KCP.

NIOSH assumes that the air concentration of uranium at the beginning of the residual period on 

March 1, 1955, was 5,480 dpm/m3. This is the bounding concentration used during the uranium 

machining operations. Hence, this is the appropriate starting point for dose reconstruction during 

the residual period and is consistent with the guidance provided in OTIB-0070.

Also, in accordance with OTIB-0070, NIOSH assumes that the concentration of dust on surfaces 

at the beginning of the residual period reflects the buildup of residue associated with a deposition 

velocity of 0.00075 m/sec for a 30-day period, as follows:

5,480 dpm/m3 × 0.00075 m/sec × 30 days × 86,400 sec/day = 10,653,120 dpm/m2

Given this activity on surfaces, NIOSH applied a resuspension factor of 1E-5/m and derived an 

airborne dust loading at the beginning of the residual period of 106.5 dpm/m3, which is 

consistent with guidance provided in OTIB-0070.

The SEC PER goes on to explain that this airborne dust loading will decline due to natural 

attenuation, because machining operations had ceased on March 1, 1955. There are basically 

two approaches that can be used to evaluate the rate of decline of this airborne concentration. 

One approach is to use a natural attenuation factor of 0.00067/day, as recommended in OTIB0070 and which SC&A believes is a reasonably conservative value, or make use of airborne dust 

loading measurements made at a later date and derive the rate of decline in the airborne dust 
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loading by fitting an exponentially declining function between the derived dust loading on March 

1, 1955, and the dust loading measured at a later date, prior to the start-up of other uranium 

operations. The SEC PER explains that dust loading measurements were made on May 23, 

1958, prior to the start of DU operations, and the maximum value was reported as 49 pCi/m3(or 

108.9 dpm/m3).

Note that the measured maximum dust loading of 108.9 dpm/m3on May 23, 1958, is comparable 

to the derived dust loading of 106.5 dpm/m3derived as representative of the dust loading at the 

beginning of the residual period. Because of this, NIOSH assumes that the dust loading during 

the residual period from March 1, 1955, until large scale DU operations began in 1958 remains 

constant at 108.9 dpm/m3. This is an interesting outcome, because it raises a couple of 

questions: (1) is the 5,480 dpm/m3 adequately conservative for the operations period, (2) is the 

deposition period of 30 days adequately long, and (3) is the resuspension factor of 1E-5/m 

sufficiently bounding. The reason we raise these questions is we believe that the airborne dust 

loadings should have declined from March 1, 1955, until 1958, but they did not. We believe that 

the assumed dust loading of 5,480 dpm/m3is certainly bounding as the starting point for the 

airborne uranium dust loadings on March 1, 1955. However, there is evidence from previous 

work performed by SC&A (SC&A 2013) that the time period for buildup of dust (i.e., 30 days) 

may be too short and the resuspension factor could be higher by perhaps a factor of 10 based on 

SC&A’s previous reviews of resuspension factors, especially at sites where there is a lot of 

activity. However, it is also possible that NIOSH was overly conservative by using the highest 

dust loading observed in 1958 of 108.9 dpm/m3. SC&A searched the Site Research Database 

(SRDB) to capture the air sampling data that were collected in the Main Manufacturing Building 

in 1958. We captured 36 samples, and summarized their distribution in the following plot 

(Exhibit E).

Exhibit E. Plot of 1958 Air Sampling Data for KCP Main Manufacturing Building
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Exhibit F. Summary Table of 1958 Air Sampling Data for KCP

Metric Value Units

# Positive Samples 36 Samples

GM 1.086E-16 μCi/cc

GSD 426.36 -

GM*GSD 4.639E-14 μCi/cc

As previously described, NIOSH selected 49 pCi/m3as the airborne dust loading due to 

resuspension at the end of the residual period in 1958. This corresponds to a concentration of 

4.9E-11 μCi/cc, which appears to be the highest measured concentration. The GM is 

1.09E-16 μCi/cc, or 1.1E-4 pCi/m3, which would be a more appropriate value for deriving the 

slope of the attenuation factor. Accordingly, the approach used by NIOSH in the SEC PER to 

estimate the airborne uranium dust loading during the residual period from March 1, 1955, to 

1958 is extremely claimant favorable. A strategy that would be more in keeping with OTIB0070 would have been to use the GM concentration as the airborne dust loading at the end of the 

residual period. Again, it appears that NIOSH is sacrificing plausibility in favor of ensuring that 

they meet the Criterion 2 (exclusivity) requirements. These are judgment calls, which, in this 

application, appear to greatly favor the claimants.

Given the uranium dust loading, NIOSH assumes that workers in the Main Manufacturing 

Building were exposed to this airborne dust loading for 2,000 hours per year. Other general 

laborers are assumed to spend 50% of their time in the Main Manufacturing Building, as per 

TBD-6000, page 49. Of course, this assumption is somewhat arbitrary, but given the 

conservatism inherent in the average dust loading during the residual period, this assumption is 

not unreasonable. In addition, it might be difficult to determine who should be assigned 

2,000 hrs/yr versus 1,000 hrs/yr exposure duration. However, this is an implementation issue 

that is appropriately evaluated as part of dose reconstruction reviews.

The SEC PER states that ingestion exposures to uranium should be based on OCAS-TIB-009 

(OCAS 2004) protocols; SC&A has reviewed this protocol and has found it acceptable.

CONCLUSIONS

We conclude that the approach adopted in the SEC PER to reconstruct internal exposures to 

uranium during the uranium machining operations from 1950 to 1955 and during the residual 

period, from March 1, 1955, to the beginning of the DU operations in 1958, is scientifically 

sound and extremely claimant favorable (as long as there were no other radiological operations 

taking place in the Main Manufacturing Building during this time period), but is deemed to be 

acceptable as a means to ensure compliance with the Criterion 2 Exclusivity Requirements.
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REFERENCES

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on Use of Surrogate Data. May 2010.

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. 

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Johnson, W. M., 1952. Safety Survey - August 4-7, 1952, correspondence to W. B. Paine, August 

28, 1952, SRDB Ref ID: 128316.

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Mahaffey, J. W., 1952. History of Production Machining of Uranium, FMPC-28, Production 

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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.

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