DRAFT 

REPORT TO THE ADVISORY BOARD 

ON RADIATION AND WORKER HEALTH

National Institute for Occupational Safety and Health 

SC&A’S BLIND DOSE RECONSTRUCTION OF CASE 

#[REDACTED] FROM THE ALLIED CHEMICAL PLANT 

Contract No. 200-2009-28555

SCA-TR-BDR2014-CN[REDACTED]

Prepared by 

Douglas Farver 

John Mauro, PhD 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, Virginia 22182 

February 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 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.
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

2 of 30

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.

S. Cohen & Associates:

Technical Support for the Advisory Board on

Radiation & Worker Health Review of

NIOSH Dose Reconstruction Program

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Effective Date: 

Draft – February 21, 2014

Revision No.

0 (Draft)

SC&A’S BLIND DOSE RECONSTRUCTION 

OF CASE #[REDACTED] FROM THE 

ALLIED CHEMICAL PLANT 

Page 2 of 30

Task Manager:

_________________________ Date: __________

Douglas Farver, CHP

Supersedes:

NA

Project Manager:

________________________ Date: ___________

John Stiver, MS, CHP

Reviewers:

 Kathy Behling

 John Stiver

Record of Revisions

Revision 

Number Effective Date Description of Revision

0 (Draft) 02/21/2014 Initial issued.
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

3 of 30

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 

Executive Summary ........................................................................................................................ 5

Relevant Background Information ...................................................................................... 5

Presentation of Results ........................................................................................................ 5

Section I: DR–Method A ............................................................................................................... 8

I.1 Summary Background Information ........................................................................ 8

I.1.1 SC&A Blind DR Approach ........................................................................ 8

I.2 External Doses ........................................................................................................ 9

I.2.1 Photon Doses .............................................................................................. 9

I.3 Occupational Medical Dose .................................................................................. 11

I.4 Internal Doses ....................................................................................................... 11

I.4.1 Uranium and Thorium Doses .................................................................... 11

I.4.2 Dose from Radon ...................................................................................... 14

I.4.3 Environmental Dose.................................................................................. 14

I.5 Radiological Incidents .......................................................................................... 14

I.6 Summary Conclusions .......................................................................................... 14

I.7 References ............................................................................................................. 14

Appendix I-A: IREP Input – Lung............................................................................................... 16

Section II: DR–Method B ............................................................................................................ 19

II-1 Dose Reconstruction Overview ............................................................................ 19

II.2 Relevant Background Information ........................................................................ 19

II.3 Facility Description and DR Strategy ................................................................... 20

II.4 Information Useful in Developing and Implementing a DR Strategy for This 

Worker .................................................................................................................. 22

II.5 Reconstruction of Internal Doses Using a Maximizing Approach ....................... 25

II.5.1 Internal Exposures from Phosphates ......................................................... 25

II.5.2 Internal Exposures from Uranium Recovery ............................................ 25

II.5.3 Radon Exposures ...................................................................................... 27

II.6 DR Using a Minimizing Approach ....................................................................... 28

II.7 Conclusions ........................................................................................................... 28

II.8 References ............................................................................................................. 28
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

4 of 30

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.

LIST OF TABLES 

Table ES-1. Derived Dose Estimates ............................................................................................. 6

Table ES-2. Approach Used by SC&A’s DR–Method A and DR–Method B for 

Calculating Doses for the ACP Worker ................................................................... 7

Table I-1. Summary of SC&A-Derived External/Internal Dose Estimates ................................... 9

Table I-2. Effective Dose Conversion Factors and Energy Distributions ................................... 10

Table I-3. Annual Photon Doses from Operations....................................................................... 10

Table I-4. Residual Photon Doses ................................................................................................ 10

Table I-5. Relative Radionuclide Concentrations and Intakes ..................................................... 12

Table I-6. Adjusted Intakes for Uranium and Thorium during the Residual Period ................... 13

Table I-7. Summary of Internal Doses ......................................................................................... 13

Table II-1. Intakes from Operation of the Phosphate Plant ......................................................... 25

Table II-2. Intake Rates from Operation of the Uranium Recovery Plant ................................... 26
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

5 of 30

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.

EXECUTIVE SUMMARY 

Under Contract No. 200-2009-28555, SC&A has been tasked by the Advisory Board on 

Radiation and Worker Health (Advisory Board) to performed eight blind dose reconstructions 

(DRs). This report presents the methodologies and results of our DR concerning one of the eight 

cases selected by the Advisory Board. 

To perform this blind DR, SC&A was provided with all of the Department of Energy (DOE) 

dosimetry records; the Department of Labor (DOL) correspondence, forms, and medical records; 

and the Computer-Assisted Telephone Interview (CATI) Report that were made available to the 

National Institute for Occupational Safety and Health (NIOSH) for constructing doses in behalf 

of this case. SC&A used two independent approaches to reconstruct occupational external and 

internal doses for this case. Both approaches used current guidance from NIOSH; however, for 

this case, there were no dosimetry or bioassay records. The first approach, referred to as DR–

Method A, used the spreadsheets and other tools developed by NIOSH to calculate the doses, 

whereas the second approach, referred to as DR–Method B, manually calculated the doses. 

This Executive Summary provides an overview of the case and a comparison of the results of the 

two independent DR methods. Section I of this report provides a detailed discussion of the 

approach used to reconstruct external/internal occupational radiation doses using DR–Method A,

and Section II describes the reconstruction of doses using DR–Method B. 

RELEVANT BACKGROUND INFORMATION 

According to the DOL records and the CATI Report, this case represents an energy employee 

(EE) who worked at the Allied Chemical and Dye Corporation, North Claymont, Delaware 

[referred to in this report as the Allied Chemical Plant (ACP)], from [redacted] through 

[redacted], and [redacted] through [redacted]. The EE was diagnosed with lung cancer

(ICD-9 Code 162.9) in [redacted].

According to the DOE records, the majority of the EE’s radiation exposure was received while 

working as a [redacted]. During the course of employment, the EE was not monitored for 

external photon and neutron radiation exposure, or internal radiation exposure by in-vivo or invitro bioassay methods. A description of the ACP is provided in Section I-1 of DR–Method A 

and Section II-2 of DR–Method B. 

PRESENTATION OF RESULTS 

The results of both independent DR methods are shown in Table ES-1. DR–Method A derived a 

total lung dose of 121.435 rem plus 0.812 WLM of radon, with a probability of causation (POC) 

of 85.40%; while DR–Method B derived a total lung dose of 0.235 WLM/yr of radon, with a 

POC of 64.1%. 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

6 of 30

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 ES-1. Derived Dose Estimates 

DR–Method A DR–Method B

External Dose (Occupational):

 ▪ Operations Dose

 - Photons < 30 keV 0.462 NA

 - Photons 30–250 keV 0.579 NA

 ▪ Residual Dose

 - Photons < 30 keV 0.086 NA

 - Photons 30–250 keV 0.108 NA

 ▪ Occupational Medical Dose

 - Photons 30–250 keV 1.886 NA

Internal Dose:

 - Plutonium/Americium (Alpha) 118.314 NA

Total 121.435 NA

Radon 0.812 WLM 0.235 WLM/yr

There are no technical basis documents or survey information for ACP; therefore, the dose 

reconstructors were required to search for surrogate data from other sites. In this case, DR–

Method A performed an analysis of potential external and internal exposures and assigned doses 

in the Interactive RadioEpidemiological Program (IREP) Input table accordingly based on the 

Blockson Chemical Company TBD (DCAS-TKBS-0002), as well as Characterization of 

Occupational Exposure to Radium and Radon Progeny During Recovery of Uranium from 

Phosphate Materials (ORAUT-OTIB-0043) and Dose Reconstruction During Residual 

Radioactivity Periods at Atomic Weapons Employer Facilities (ORAUT-OTIB-0070). On the 

other hand, DR–Method B performed a partial DR using two different approaches. First, 

Method B calculated internal doses using an overestimate DR approach based on Texas City 

Chemical, Inc. (TCC), information and found this method resulted in a POC >50%. DR–

Method B then employed an underestimating approach by using the U.S. Environmental 

Protection Agency (EPA) guideline of 4 pCi/l (as found in FIPR 1998) and determined that 

assigning only radon intake resulted in a POC >50% for this lung cancer case; therefore, other 

external and internal dose did not need to be included. 

A detailed description of the DR approach used by SC&A’s Method A is provided in Section I 

below. Section II of this report describes the derivation of doses using SC&A’s DR–Method B. 

For the benefit of the reader, Table ES-2 provides a summary comparison of the approaches used 

by the two SC&A DR methods for calculating doses. 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

7 of 30

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 ES-2. Approach Used by SC&A’s DR–Method A and DR–Method B for 

Calculating Doses for the ACP Worker 

Dose Element DR–Method A DR–Method B

External Dose:

 Operations 

 Residual Period

Used the 50th percentile external dose value of 

70 mrem/yr from Table 4-1 of ORAUT-OTIB0043.N/C

*

 Occupational Medical Assumed annual x-ray dose for each year of 

employment based on ORAUT-OTIB-0006. N/C

*

 Onsite Ambient N/C* N/C*

Internal

Used the uranium intake value of 44.0 pCi/day 

for U-238 and 0.605 pCi/day Th-232 from 

Table 4-3 of ORAUT-OTIB-0043, plus the ratio 

values for associated radionuclides from the 

Blockson TBD (DCAS-TKBS-0002) and 

ORAUT-OTIB-0043 to derive the potential 

intakes during the operational period (1950–

1969). DR–Method A then used these same 

intake values, adjusted for depletion rate 

according to ORAUT-OTIB-0070, for the 

residual period (1970–1975).

N/C

*

Radon

Used the radon intake value of 0.036 WLM/yr 

from Table 4-4 of ORAUT-OTIB-0043 to assign 

yearly radon intakes for the operational years 

(1950–1969), and the same value, adjusted for 

depletion rate according to ORAUT-OTIB-0070, 

for the residual period (1970–1975).

Used the potential radon intake of 

4 pCi/l in 50% equilibrium, which 

corresponds to 0.235 WLM/yr. 

The value of 4 pCi/l is the EPA 

guideline for radon as quoted in 

FIPR 1998, and was considered a 

minimizing approach.

* N/C = Not Considered in DR 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

8 of 30

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.

SECTION I: DR–METHOD A 

I.1 SUMMARY BACKGROUND INFORMATION 

This report presents the results of an independent blind dose reconstruction (DR) performed by 

S. Cohen & Associates (SC&A) for an energy employee (EE) who worked at the Allied 

Chemical and Dye Company in North Claymont, Delaware, from [redacted] to [redacted], and 

[redacted] to [redacted]. The EE was diagnosed with [redacted] carcinoma of the lung (ICD9 Code 162.9) in [redacted]. 

According to Department of Labor (DOL) records, the EE worked as a [redacted] during both 

employment periods. No employee monitoring records or site survey records were found.

In the early 1950s, Allied Chemical was involved in research and development of small pilotscale operations on uranium recovery from a phosphoric acid plant at North Claymont. The 

work was performed on a small scale under contract for the Atomic Energy Commission (AEC). 

Former employees estimated that, at most, only a few pounds of uranium concentrate were 

produced (DOE 1987).

The site was owned and operated by General Chemical Corporation. At the time of the contract 

with AEC, the company was known as the General Chemical Division of the Allied Chemical 

and Dye Corporation. Operations at the phosphoric acid plant ceased in the late 1960s, and the 

plant was demolished in the early 1970s. The contractor, Cleveland Wrecking, salvaged reusable 

building materials and disposed of the remaining rubble in local landfills. The exact location on 

the site where the AEC work was performed is not known. 

The Department of Energy (DOE) Oak Ridge Operations Office contacted Allied Chemical on 

July 16, 1977. A contact report, furnished to DOE Headquarters on December 12, 1977, 

concluded that the potential for measurable contamination at this site was insignificant due to the 

limited scale of operations (DOE 1987). Since exact dates of operations are unknown, the 

operational period is assumed to be 1950 to 1969, and the residual period from 1970–1977.

I.1.1 SC&A Blind DR Approach 

SC&A reviewed all of the DOL records provided on behalf of this employee and all of the 

NIOSH procedures relevant to this case. There is no site-specific Technical Basis Document 

(TBD) available for this site. Therefore, information on the phosphoric acid process was 

obtained from the Blockson Chemical Company TBD (DCAS-TKBS-0002); ORAUT-OTIB0043, Characterization of Occupational Exposure to Radium and Radon Progeny During 

Recovery of Uranium from Phosphate Materials; and ORAUT-OTIB-0070, Dose Reconstruction 

During Residual Radioactivity Periods at Atomic Weapons Employer Facilities. Using the 

guidance provided in these documents, SC&A manually calculated reasonable, claimantfavorable annual organ doses shown in Table I-1. Appendix I-A provides a list of SC&A’s 

annual organ doses and also includes IREP input parameters, such as energy range, distribution 

type, and uncertainty for each year. 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

9 of 30

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 I-1. Summary of SC&A-Derived External/Internal Dose Estimates 

Appendix A

Exposure Entry No.

Lung Dose 

(rem)

External Dose (Occupational):

 ▪ Operations Dose ([redacted]–[redacted])

 - Photons 30–250 keV 26–44 0.462

 - Photons >250 keV 45–63 0.579

 ▪ Residual Dose ([redacted]–[redacted])

 - Photons 30–250 keV 64–69 0.086

 - Photons >250 keV 70–75 0.108

 ▪ Occupational Medical Dose

 - Photons 30–250 keV 1–25 1.886

Internal Dose ([redacted]–[redacted]):

 - Alpha 76–107 118.314

Total 121.435

Radon Exposure ([redacted]–[redacted]): 1–25 0.812 WLM

 

SC&A determined the probability of causation (POC) for this case using these annual doses as 

input into the IREP program. The total dose shown in Table I-1 produced a POC of 85.40%

I.2 EXTERNAL DOSES 

Since the worker was neither provided with film badge or thermoluminescent dosimeters (TLDs) 

to measure external exposures, nor were bioassays performed to estimate internal exposures, 

exposures experienced by the worker were estimated using the Blockson Chemical Company 

TBD (DCAS-TKBS-0002), ORAUT-OTIB-0043, and ORAUT-OTIB-0070. In the sections that 

follow, a description is provided of how DR–Method A reconstructed the external dose to the 

lung. 

I.2.1 Photon Doses 

Since there are no dosimetry or radiological survey data upon which to reconstruct the EE’s 

external radiation exposure, Method A used the external exposure parameters given in ORAUTOTIB-0043, Section 4.1. During chemical separation in the wet acid process, radium scale 

builds up in the processing equipment. The radiation levels peak in the acid wash section, with 

dose rates as high as 10 mrem/hr (Lardinoye and Weterings 1982). Considering the nature of 

their duties, duration of work activities, and frequency of such work, a maximally exposed 

worker could receive up to 220 mrem/yr (Lardinoye and Weterings 1982). NCRP (1993) reports 

exposures for a 2,000 hr/yr occupancy at phosphogypsum stacks as 70 mrem, while Laiche and 

Scott (1991) estimated a range for that occupancy of 48 to 68 mrem. As stated in ORAUTOTIB-0043, Table 4-1, page 12, the above data may be represented with a lognormal distribution 

having a geometric mean (GM) of 70 mrem/yr, a 95th percentile value of 220 mrem/yr, and a 

geometric standard deviation (GSD) of 2.00. 

For the purposes of this DR, SC&A assumed a lognormal distribution with a GM of 0.070 rem/yr 

and a GSD of 2.00. The energy fraction and organ dose conversion factors (DCFs) for the lung 

from Appendix A of OCAS-IG-001, External Dose Reconstruction Implementation Guideline,

are shown in Table I-2. 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

10 of 30

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 I-2. Effective Dose Conversion Factors and Energy Distributions 

Allied Chemical Uranium Extraction Process

Photons

Energy Range 30–250 keV >250 keV

Energy Fraction 50% 50%

Organ DCF 0.695 0.87

DCFEffective 0.3475 0.435

I.2.1.1 Operational Period 

Although the exact dates are unknown, the period of operation is assumed to have occurred from 

1950 through 1969. SC&A calculated the photon dose to the lung for this time period assuming 

a whole body exposure of 0.070 rem/yr. Applying the DCFEffective from Table I-2 gives the 

following annual doses during the operational period 1950–1969.

Table I-3. Annual Photon Doses from Operations 

Year Annual Photon Dose 

30–250 keV photons >250 keV photons

1950–1969 0.024 rem/yr 0.030 rem/yr

The total photon dose is 1.041 rem and is shown as IREP entries #26–#63 in Appendix I.A. 

These photon doses were entered into IREP as a lognormal distribution with an uncertainty of 

2.00.

I.2.1.2 Residual Period 

The residual period begins in 1970, after the completion of operations, and is assumed to last 

until 1977 when DOE submitted its site assessment (DOE 1977). DR–Method A calculated the 

EE’s exposure to residual contamination using the guidance found in ORAUT-OTIB-0070, Dose 

Reconstruction during Residual Radioactivity Periods at Atomic Weapons Employer Facilities,

from 1970 until the EE’s last year of employment in [redacted].

ORAUT-OTIB-0070 provides guidance and adjustment factors to account for depletion of 

source term during the residual period. The adjustment factors are based on an average depletion 

rate of 0.00067 per day. 

Table I-4. Residual Photon Doses 

Year Adjustment Factor Photon Dose (rem)

30–250 keV photons >250 keV photons

[redacted] 1.000 0.024 0.030

[redacted] 0.783 0.019 0.024

[redacted] 0.613 0.015 0.019

[redacted] 0.480 0.012 0.015

[redacted] 0.376 0.009 0.011

[redacted] 0.294 0.007 0.009
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

11 of 30

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.

The total photon dose is 0.194 rem and is shown as IREP entries #64–#75 in Appendix I.A. The 

recorded photon doses were entered into IREP as a lognormal distribution with an uncertainty of 

2.00.

I.3 OCCUPATIONAL MEDICAL DOSE 

In addition to the estimated dose received from site operations and residual contamination, the 

doses received from diagnostic x-ray procedures that were required as a condition of 

employment were also included in the overall dose. Since no medical records for the EE were 

found, the x-ray dose was based on an annual PA chest exam and the dose information in 

Table A-7 of ORAUT-OTIB-0006, Dose Reconstruction from Occupational Medical X-Ray 

Procedures. For the years [redacted] to [redacted], the EE’s annual lung dose from medical exams 

was 0.084 rem/yr. For the years [redacted] to [redacted], the medical dose was 0.042 rem/yr. 

The EE’s total occupational medical dose of 1.886 rem is shown in IREP entries #1–#25 of 

Appendix I.A.

In order to provide the most claimant-favorable results, the annual occupational medical dose 

values were entered into IREP as a normal distribution with 30% uncertainty and a photon 

energy range of 30–250 keV. 

I.4 INTERNAL DOSES 

I.4.1 Uranium and Thorium Doses 

There are no process records, survey records, or dosimeter records from the Allied Chemical and 

Dye site in Claymont, Delaware. However, the wet chemical phosphoric acid treatment process 

used there is similar to the process used in Building 55 at the Blockson Chemical Company site. 

The following assumptions for isotopic ratios in the phosphoric acid stream are based on 

information in the Blockson Site Profile (DCAS-TBKS-0002) and ORAUT-OTIB-0043, 

Characterization of Occupational Exposure to Radium and Radon Progeny during Recovery of 

Uranium from Phosphate Materials: 

(1) 85% of U reports to phosphoric acid (DCAS-TKBS-0002); ORAUT-OTIB-0043 cites 

“approximately 86%.”

(2) 4% of Ra-226 reports to acid (DCAS-TKBS-0002). 

(3) Thorium reports to the acid in same proportion as uranium (DCAS-TKBS-0002, 

ORAUT-OTIB-0043). 

(4) U-238:Th-232 radioactivity ratio in Blockson's rock was 30:1. However, ORAUTOTIB-0043 uses a U-238/Th-232 ratio of 72:1 based on material averages from several 

facilities. Since the exact composition of the Allied material is unknown, the 

U-238/Th-232 ratio of 72:1 is used for this DR. Th-232 progeny are assumed to be in 

equilibrium. Although most of the Ra-228 would have been separated and removed with 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

12 of 30

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.

the phosphogypsum, it is assumed to be in equilibrium with Th-232 for dose modeling to 

allow for ingrowth over the operational and residual contamination period (DCASTKBS-0002). 

(5) Pb-210 and Po-210 assumed to report to the acid the same as U-238 (DCAS-TKBS-0002, 

ORAUT-OTIB-0043). 

(6) The daily 8-hour U-238 intake (in equilibrium with progeny) and Th-232 intake (in 

equilibrium with progeny) are 44.0 pCi/day (1.63 Bq/day) and 0.605 pCi/day 

(0.0224 Bq/day), respectively (using best-estimate hourly intake values from Table 4-3, 

page 13 of ORAUT-OTIB-0043). 

(7) The U3O8 product produced from wet phosphoric acid by filtering the precipitated 

uranium most closely corresponds to the clearance rate associated with Type M uranium 

material (DCAS-TKBS-0002).

(8) Thorium could have been Type M or Type S, and polonium could have been F or M. 

Therefore, the thorium and polonium solubility types were selected based on the types 

that deliver the largest dose to the target organ (DCAS-TKBS-0002). For this case, the 

solubility types of thorium and polonium are S and M, respectively. Pb-210 is Type F. 

These assumptions result in the following ratios and intakes: 

Table I-5. Relative Radionuclide Concentrations and Intakes 

Radionuclide Ratio to U-238 Daily Intake Solubility 

pCi/day Bq/day Type

U-238 1 44.0 1.628 M

U-234 1 44.0 1.628 M

Th-230 1 44.0 1.628 S

Po-210 1 44.0 1.628 M

Pb-210 1 44.0 1.628 F

Ra-226 4% = 0.040 1.76 0.0765 M

Th-232 1/72 = 0.014 0.605 0.0224 S

Th-228 1/72 = 0.014 0.605 0.0224 S

Ra-228 1/72 = 0.014 0.605 0.0224 M

I.4.1.1 Operations Period 

The daily intakes listed in Table I-5 were assumed to have occurred during the operations period 

from 1950 through 1969. The EE’s internal doses for the operations period were calculated 

assuming a chronic exposure to the intakes listed in Table I-5 during the periods [redacted]–

[redacted] and [redacted]–[redacted].
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

13 of 30

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.

I.4.1.2 Residual Period 

No survey data were available to estimate the levels of residual radiological contamination. The 

residual period began in 1970, after the completion of operations, and is assumed to have lasted

until 1977, when DOE submitted its site assessment. SC&A’s DR–Method A calculated the 

EE’s internal exposure to residual contamination using the guidance found in ORAUT-OTIB0070, Dose Reconstruction during Residual Radioactivity Periods at Atomic Weapons Employer 

Facilities, from 1970 until the EE’s last year of employment in [redacted].

ORAUT-OTIB-0070 provides guidance and adjustment factors to account for depletion of 

source term during the residual period. The adjustment factors are based on an average depletion 

rate of 0.00067 per day. The adjustment factors were applied to all the intakes shown in 

Table I-5. Table I-6 shows how the factors were applied to the U-238 and Th-232 intakes; the 

adjustment factors were also applied to the other radionuclides. 

Table I-6. Adjusted Intakes for Uranium and Thorium during the Residual Period 

Year Adjustment 

Factor

Adjusted Intake (pCi/d)

U-238 Th-232

[redacted] 1.000 44.0 0.014

[redacted] 0.783 34.4 0.011

[redacted] 0.613 27.0 0.009

[redacted] 0.480 21.1 0.007

[redacted] 0.376 16.5 0.005

[redacted] 0.294 12.9 0.004

The EE’s internal doses from [redacted]–[redacted] and [redacted]–[redacted] are shown in 

Table I-7.

Table I-7. Summary of Internal Doses 

Radionuclide Solubility 

Type Dose (rem)

U-238 M 16.962

U-234 M 21.795

Th-230 S 50.611

Po-210 M 22.348

Pb-210 F 0.492

Ra-226 M 1.031

Th-232 S 1.096

Th-228 S 3.867

Ra-228 M 0.112

Total: 118.314

The internal doses are shown as IREP entries #76–#107 in Appendix I.A and were entered as a 

lognormal distribution with an uncertainty of 1.270. 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

14 of 30

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.

I.4.2 Dose from Radon 

Radon exposure was assessed using guidance from ORAUT-OTIB-0043, Section 4.2. This 

guidance is based on data from the Florida Institute of Phosphate Research Report (FIPR 1998) 

for activities relevant to uranium extraction. The combined measurements formed a set of 130 

data points that have a GM of 0.751 pCi/L and a GSD of 1.989 (ORAUT-OTIB-0043, Table 4-4, 

page 14). The exposure to the respiratory tract from radon progeny, in working levels per year 

(WLM/yr), was calculated based on an equilibrium factor of 0.4 and a conversion of 1 WL per 

100 pCi/L. 

WLM/yr = 0.751 pCi/L × 0.4 × 1 WL/100 pCi/L × 12 M/yr 

WLM/yr = 0.036 WLM/yr 

The annual exposure was calculated to be 0.036 WLM/yr during operations. This value was 

applied for the years [redacted]–[redacted] and [redacted]–[redacted].

In the absence of any residual radon information, the adjustment factors shown in Table I-6 were 

applied to the annual radon exposure of 0.036 WLM/yr for years [redacted]–[redacted]. The 

EE’s total radon exposure is 0.812 WLM, which is shown as IREP entries #1–#25 under “Radon 

Exposure Inputs” in Appendix I-A, and were entered as a lognormal distribution with an 

uncertainty of 1.989. 

I.4.3 Environmental Dose 

Since the EE was assessed an internal dose for the entire employment period, no additional 

environmental dose was calculated. 

I.5 RADIOLOGICAL INCIDENTS

No site or EE records were found. Therefore, no radiological incidents were identified. 

I.6 SUMMARY CONCLUSIONS 

The EE worked at the Allied Chemical and Dye Company in Claymont, Delaware, from 

[redacted] to [redacted] and [redacted] to [redacted] as a [redacted]. There are no site or 

employee monitoring records available. The EE was diagnosed with lung cancer in [redacted]. 

The DR derived a total external and internal dose of 121.435 rem to the lung, plus 0.812 WLM 

of radon. The total POC for the primary lung cancer was calculated using the NIOSH IREP 

(v.5.7) and determined to be 85.40%. 

I.7 REFERENCES 

DCAS-TKBS-0002. 2010. Technical Basis Document for Atomic Energy Operations at 

Blockson Chemical Company, Joliet, Illinois. Rev. 03, Division of Compensation Analysis and 

Support, Cincinnati, Ohio. December 20, 2010. 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

15 of 30

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.

DOE 1987. FUSRAP Elimination Report for Former Allied Chemical Corporation, Chemicals 

Company (Now General Chemical Corporation), North Claymont, Delaware; Department of 

Energy Report DE.01-1; Circa 1987. 

DOE 1977. C.A. Keller (DOE Oak Ridge Operations) to W.E.Mott (DOE HQ), Subject: Report 

of Findings: Allied Chemical Corporation Sites at North Claymont, Delaware, Marcus Hook, 

Pennsylvania, and Baltimore, Maryland; Department of Energy Memorandum DE.01-2. 

December 12, 1977. 

FIPR 1998. Evaluation of Exposure to Technologically Enhanced Naturally Occurring 

Radioactive Materials (TENORM) in the Phosphate Industry, Publication 05-046-155, Florida 

Institute of Phosphate Research, Bartow, Florida. 

Laiche, T.P., and L.M. Scott, 1991. “A Radiological Evaluation of Phosphogypsum,” Health 

Physics, volume 60, number 5, pp. 691–693. 

Lardinoye, M.H., and K. Weterings, 1982. “Unexpected 226Ra Build-up in Wet Process 

Phosphoric-Acid Plants,” Health Physics, volume 42, number 4, pp. 503–514. 

NCRP (National Council on Radiation Protection and Measurements) Report No. 118, 1993, 

Recommendations of the National Council on Radiation Protection and Measurements, 

Radiation Protection in the Mineral Extraction Industry, Bethesda, Maryland, November 1993. 

OCAS-IG-001. 2007. External Dose Reconstruction Implementation Guideline, Rev. 3, 

National Institute for Occupational Safety and Health, Office of Compensation Analysis and 

Support, Cincinnati, Ohio. November 21, 2007. 

ORAUT-OTIB-0006. 2011. Technical Information Bulletin: Dose Reconstruction from 

Occupationally Related Diagnostic X-ray Procedures, Rev. 04, Oak Ridge Associated 

Universities Team, Cincinnati, Ohio. June 20, 2011. 

ORAUT-OTIB-0043. 2006. Characterization of Occupational Exposure to Radium and Radon 

Progeny during Recovery of Uranium from Phosphate Materials, Rev. 00, Oak Ridge Associated 

Universities Team, Cincinnati, Ohio. January 6, 2006. 

ORAUT-OTIB-0070. 2012. Technical Information Bulletin: Dose Reconstruction during 

Residual Radioactivity Periods at Atomic Weapons Employer Facilities, Rev. 01, Oak Ridge 

Associated Universities Team, Cincinnati, Ohio. March 5, 2012. 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

16 of 30

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.

APPENDIX I-A: IREP INPUT – LUNG 

EXPOSURE INFORMATION

Number of exposures

107

Exposure 

#

Exposure 

Year

Exposure 

Rate Radiation Type

Dose 

Distribution 

Type Parameter 1 Parameter 2 Parameter 3

1 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

2 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

3 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

4 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

5 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

6 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

7 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

8 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

9 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

10 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

11 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

12 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

13 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

14 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

15 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

16 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

17 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

18 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

19 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

20 [redacted] acute photons E=30–250keV Normal 0.084 0.025 0.000

21 [redacted] acute photons E=30–250keV Normal 0.042 0.013 0.000

22 [redacted] acute photons E=30–250keV Normal 0.042 0.013 0.000

23 [redacted] acute photons E=30–250keV Normal 0.042 0.013 0.000

24 [redacted] acute photons E=30–250keV Normal 0.042 0.013 0.000

25 [redacted] acute photons E=30–250keV Normal 0.042 0.013 0.000

26 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

27 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

28 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

29 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

30 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

31 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

32 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

33 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

34 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

35 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

36 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

37 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

38 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

39 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

40 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

41 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

42 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

43 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

44 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

45 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

17 of 30

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.

Appendix I-A: IREP Input – Lung (continued) 

46 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

47 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

48 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

49 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

50 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

51 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

52 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

53 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

54 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

55 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

56 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

57 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

58 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

59 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

60 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

61 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

62 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

63 [redacted] chronic photons E>250keV Lognormal 0.031 2.000 0.000

64 [redacted] chronic photons E=30–250keV Lognormal 0.024 2.000 0.000

65 [redacted] chronic photons E=30–250keV Lognormal 0.019 2.000 0.000

66 [redacted] chronic photons E=30–250keV Lognormal 0.015 2.000 0.000

67 [redacted] chronic photons E=30–250keV Lognormal 0.012 2.000 0.000

68 [redacted] chronic photons E=30–250keV Lognormal 0.009 2.000 0.000

69 [redacted] chronic photons E=30–250keV Lognormal 0.007 2.000 0.000

70 [redacted] chronic photons E>250keV Lognormal 0.030 2.000 0.000

71 [redacted] chronic photons E>250keV Lognormal 0.024 2.000 0.000

72 [redacted] chronic photons E>250keV Lognormal 0.019 2.000 0.000

73 [redacted] chronic photons E>250keV Lognormal 0.015 2.000 0.000

74 [redacted] chronic photons E>250keV Lognormal 0.011 2.000 0.000

75 [redacted] chronic photons E>250keV Lognormal 0.009 2.000 0.000

76 [redacted] chronic alpha Lognormal 3.645 1.270 0.000

77 [redacted] chronic alpha Lognormal 4.347 1.270 0.000

78 [redacted] chronic alpha Lognormal 4.552 1.270 0.000

79 [redacted] chronic alpha Lognormal 4.693 1.270 0.000

80 [redacted] chronic alpha Lognormal 4.797 1.270 0.000

81 [redacted] chronic alpha Lognormal 1.231 1.270 0.000

82 [redacted] chronic alpha Lognormal 4.237 1.270 0.000

83 [redacted] chronic alpha Lognormal 4.784 1.270 0.000

84 [redacted] chronic alpha Lognormal 4.891 1.270 0.000

85 [redacted] chronic alpha Lognormal 4.963 1.270 0.000

86 [redacted] chronic alpha Lognormal 5.018 1.270 0.000

87 [redacted] chronic alpha Lognormal 5.062 1.270 0.000

88 [redacted] chronic alpha Lognormal 5.099 1.270 0.000

89 [redacted] chronic alpha Lognormal 5.129 1.270 0.000

90 [redacted] chronic alpha Lognormal 5.155 1.270 0.000

91 [redacted] chronic alpha Lognormal 5.178 1.270 0.000

92 [redacted] chronic alpha Lognormal 5.199 1.270 0.000

93 [redacted] chronic alpha Lognormal 5.217 1.270 0.000

94 [redacted] chronic alpha Lognormal 5.234 1.270 0.000

95 [redacted] chronic alpha Lognormal 5.249 1.270 0.000

96 [redacted] chronic alpha Lognormal 5.263 1.270 0.000
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

18 of 30

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.

Appendix I-A: IREP Input – Lung (continued) 

97 [redacted] chronic alpha Lognormal 4.485 1.270 0.000

98 [redacted] chronic alpha Lognormal 3.725 1.270 0.000

99 [redacted] chronic alpha Lognormal 3.088 1.270 0.000

100 [redacted] chronic alpha Lognormal 2.559 1.270 0.000

101 [redacted] chronic alpha Lognormal 2.125 1.270 0.000

102 [redacted] chronic alpha Lognormal 0.928 1.270 0.000

103 [redacted] chronic alpha Lognormal 0.657 1.270 0.000

104 [redacted] chronic alpha Lognormal 0.550 1.270 0.000

105 [redacted] chronic alpha Lognormal 0.473 1.270 0.000

106 [redacted] chronic alpha Lognormal 0.414 1.270 0.000

107 [redacted] chronic alpha Lognormal 0.369 1.270 0.000

LUNG CANCER INPUTS

Exposure from Smoking History

Radon + Other Sources [redacted]

Radon Exposure Information

Number of radon exposures

25

Exposure # Exposure 

Year Dose Distribution Type Parameter 1 Parameter 2 Parameter 3

1 [redacted] Lognormal 0.036 1.989 0

2 [redacted] Lognormal 0.036 1.989 0

3 [redacted] Lognormal 0.036 1.989 0

4 [redacted] Lognormal 0.036 1.989 0

5 [redacted] Lognormal 0.036 1.989 0

6 [redacted] Lognormal 0.036 1.989 0

7 [redacted] Lognormal 0.036 1.989 0

8 [redacted] Lognormal 0.036 1.989 0

9 [redacted] Lognormal 0.036 1.989 0

10 [redacted] Lognormal 0.036 1.989 0

11 [redacted] Lognormal 0.036 1.989 0

12 [redacted] Lognormal 0.036 1.989 0

13 [redacted] Lognormal 0.036 1.989 0

14 [redacted] Lognormal 0.036 1.989 0

15 [redacted] Lognormal 0.036 1.989 0

16 [redacted] Lognormal 0.036 1.989 0

17 [redacted] Lognormal 0.036 1.989 0

18 [redacted] Lognormal 0.036 1.989 0

19 [redacted] Lognormal 0.036 1.989 0

20 [redacted] Lognormal 0.036 1.989 0

21 [redacted] Lognormal 0.028 1.989 0

22 [redacted] Lognormal 0.022 1.989 0

23 [redacted] Lognormal 0.017 1.989 0

24 [redacted] Lognormal 0.014 1.989 0

25 [redacted] Lognormal 0.011 1.989 0
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

19 of 30

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.

SECTION II: DR–METHOD B 

II-1 DOSE RECONSTRUCTION OVERVIEW 

Section II of this report presents the results of SC&A’s blind DR for Case #[redacted] using 

DR– Method B.

For this case associated with work at the Allied Chemical Plant in North Claymont, Delaware, 

there are neither dosimetry/bioassay records, nor a site profile. There are, however, a number of 

records in NIOSH’s Site Research Database (SRDB) for this facility, along with the CATI 

Report and information from other sites that, in theory, can serve as useful surrogates to help 

assign upper bound external and internal doses to this worker. 

II.2 RELEVANT BACKGROUND INFORMATION 

According to the DOL records, this case represents an EE who worked at the Allied Chemical 

Plant in North Claymont, Delaware, from [redacted] to the beginning of [redacted]. The EE 

was diagnosed with lung cancer in [redacted].

It is worth noting that the type and extent of the Atomic Weapons Employers (AWE) activities 

performed at the Allied Chemical facility in the North Claymont, Delaware, were very different 

than those performed at the Allied Chemical facility near Metropolis, Illinois. We mention this 

because the facility near Metropolis has received a great deal of attention by NIOSH; a site 

profile was prepared for the facility, and SC&A has performed a review of the site profile. In 

addition, a Special Exposure Cohort (SEC) petition evaluation report was prepared by NIOSH 

for the Metropolis facility, and the Advisory Board recommended an SEC for the facility. The 

Allied Chemical facility in North Claymont bears very little resemblance to the Allied Chemical 

facility near Metropolis and cannot be used as a surrogate for this facility. This is apparent when 

reviewing the Formerly Utilized Remediation Report prepared by DOE (DOE 1985) for the 

North Claymont facility. It is also apparent that, due to the lack of a site profile for the North 

Claymont facility and the lack of any dosimetry or bioassay data for this EE, reconstructing the 

doses for this worker will likely require the use of surrogate data, if such data can be identified. 

Inspection of the CATI and DOL files revealed that this EE was employed by Allied Chemical 

from [redacted] to [redacted], and that the EE worked as a [redacted] and [redacted]. The 

CATI also reveals that the EE worked some overtime, and the interviewee had no knowledge 

regarding whether the EE was assigned dosimetry, was monitored under a bioassay program, 

was involved in any radiological incidents, or received medical x-ray examinations as a 

condition of employment. Also, inspection of the records for this claimant as provided by 

NIOSH for this blind DR reveals that there are no film badge or bioassay data for this EE. In 

addition, there is no site profile for this facility. As a result, this blind DR is performed using 

information in the SRDB for this facility, the CATI, and surrogate data, as applicable. 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

20 of 30

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.

II.3 FACILITY DESCRIPTION AND DR STRATEGY

Because of the lack of a site profile, we reviewed the SRDB and found about 60 citations

pertinent to Allied Chemical and Dye Corporation in North Claymont, Delaware. A review of 

these documents revealed that Allied Chemical and Dye Corporation was formed in December 

1920 as a means of ending foreign domination of the chemical industry with respect to the 

production and manufacturing of a broad range of plastics, industrial and agricultural products, 

and also chemicals (Monti 2009). Formerly Utilized Sites Remedial Action Program, 

Elimination Report for Allied Chemical Corporations, Chemical Company, North Claymont, 

Delaware (DOE 1985) explains that: 

In the early 1950’s Allied Chemical was involved in research and development 

and small pilot scale operations on uranium recovery from a phosphoric acid 

plant at North Claymont. The work under AEC contracts AT(59-1)-610 and 

AT(49-6)-913 was performed on a small scale. Former AEC employees estimated 

that, at most, only a few pounds of uranium concentrate were produced.

These operations ceased in the late 1960’s and the plant was demolished in the

early 1970’s.

According to discussions with former Oak Ridge Division of Raw Materials (DRM) staff, 

(1) [Redacted], (2) [Redacted] and (3) [Redacted], the contract operations were small and the 

uranium separated and recovered during the contract period was only a few pounds. It was noted 

that the North Claymont facility work focused on filtration development and was not apparently 

successful. As a result of the insignificant amount of uranium recovered during the contract 

period, further investigation to locate and access the AEC contract work area was not warranted 

in 1977 and no further assessment of the Allied Chemical site was made (Mott 1977).

None of the documents on the SRDB provided any information or estimate on the amount of 

phosphate ore that was processed and handled during the AT-(49-1)-610 and AT-(49-6)-913 

contracts period in order to obtain the few pounds of uranium. It is also unknown if the 

phosphate ore processed at Allied Chemical was part of their regular operations or only part of 

the pilot scale research and development contract with AEC. There was quite a bit of 

redundancy among the documents on the SRDB; however, ERDA 1976 and Mott 1977 provide 

the most information.

The implications of the material we were able to review are that (1) the AWE period covers 

approximately a 15- to 20-year period; (2) during this time, it is likely that phosphate rock was 

on site and processed, and workers may have been exposed to the naturally occurring 

radionuclides associated with phosphate rock and its processing; (3) it appears that the North 

Claymont plant was involved in ongoing production of phosphoric acid during this time; (4) pilot 

studies were performed to separate uranium from the phosphoric acid, which we presume was 

produced from phosphate rock; and (5) a few pounds of a yellowcake-type material was actually 

produced, which also could have resulted in external and internal exposure to uranium oxide, 

probably yellowcake. This understanding sets the stage for performing a blind DR. However, it 

also creates a dilemma; it seems inconceivable that a worker could have experienced a protracted 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

21 of 30

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.

exposure to uranium over a 15- to 20-year time period if the operations were limited to a pilot 

scale study involving only a few pounds of uranium.

DOE 1985 further concludes that, due to the small quantities of uranium processed at the facility, 

and the fact that the building was demolished and the rubble removed, any residual 

contamination would be negligible and no further action was necessary. This conclusion is 

supported by a letter from W.E. Mott, Director, Division of Environmental Control Technology

(Mott 1977).

Our review of the SRDB was unable to uncover any information regarding specific quantities of 

phosphate ore processed, the amount and type of uranium produced (except that it was only a 

few pounds), the methods used to separate and purify the uranium from phosphate ore, airborne 

dust loadings of phosphate ore or uranium, radon levels, radiation fields, or external or internal 

dosimetry of any type. As best we can tell, it is likely that the activities at the North Claymont 

facility might have been conceptually similar to the activities that took place at Blockson 

Chemical Company and TCC, which were both previously evaluated in depth by NIOSH, the 

Advisory Board, and SC&A. However, the main difference between Blockson and TCC and the 

North Claymont facility is that Blockson produced relatively large quantities of yellowcake 

(U3O8), about 5,000 pounds per month; TCC produced a total of about 300 pounds of 

yellowcake; and the Claymont facility produced only a few pounds of yellowcake from 

phosphate rock.

In light of this information, we decided to begin our blind DR by considering an efficiency 

approach, in accordance with the provisions of 40 CFR Part 82 (k), which states the following: 

(k) At any point during steps of dose reconstruction described in paragraphs (f) 

through (j) of this section, NIOSH may determine that sufficient research and 

analysis has been conducted to complete the dose reconstruction. Research and 

analysis will be determined sufficient if one of the following three conditions is 

met: 

(1) From acquired experience, it is evident the estimated cumulative dose is 

sufficient to qualify the claimant for compensation (i.e., the dose produces a 

probability of causation of 50% or greater);

(2) Dose is determined using worst case assumptions related to radiation 

exposure and intake, to substitute for further research and analyses; or, 

(3) Research and analysis indicated under steps described in paragraphs (f)–

(j) of this section have been completed. Worst-case assumptions will be 

employed under condition 2 to limit further research and analysis only for 

claims for which it is evident that further research and analysis will not 

produce a compensable level of radiation dose (a dose producing a 

probability of causation of 50% or greater), because using worst-case 

assumptions it can be determined that the employee could not have incurred a 

compensable level of radiation dose. For all claims in which worst-case 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

22 of 30

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.

assumptions are employed under condition 2, the reasoning that resulted in 

the determination to limit further research and analysis will be clearly 

described in the draft of the dose reconstruction results reported to the 

claimant under § 82.25 and in the dose reconstruction results reported to the 

claimant under § 82.26.

As a first step in our strategy, DR–Method B considered using surrogate data employing a 

bounding approach by using the DR protocols adopted for use at the TCC and Blockson 

facilities. However, given the quantities of uranium involved and the presumed quantities of 

phosphate rock involved, any dose reconstructed using the information, data, and records at 

Blockson and TCC would result in a gross overestimate of the exposures that this EE might have 

experienced at the North Clayton facility. Hence, it is our judgment that these facilities cannot 

be used as a surrogate for the North Claymont facility to grant compensation, but could be used 

to deny compensation.

We have taken this position based on the following statement provided in Section J, Use of 

Efficiency Methods, in Section II, Summary of Public Comments in the preamble to the rule:

Dose estimates sufficiently high to qualify a claimant for compensation 

definitively cannot be based on worst case assumptions employed as an efficiency 

measure to abbreviate research and analysis.

Our strategy also considered the possibility of performing a minimizing analysis, which would 

assign the lowest plausible dose that this EE might have experienced, and if the POC exceeds 

50%, the analysis is complete and a recommendation to compensate this worker can be made. 

The following sections present how we implemented each strategy and their results.

II.4 INFORMATION USEFUL IN DEVELOPING AND IMPLEMENTING A DR 

STRATEGY FOR THIS WORKER

Based on the very limited information summarized above, the EE likely experienced exposure to 

the radionuclides associated with handling and processing of phosphate ore during the AWE

period (i.e., from the early 1950s to the late 1960s), including radon, and also some exposure to 

uranium during the pilot-scale uranium separations studies that produced a few pounds of 

yellowcake. Clearly, the dilemma is that apparently only a few pounds of uranium were 

produced, and it is difficult to conceive of a circumstance where such small quantities of uranium 

could represent a significant chronic source of exposure over approximately a 15- to 20-year 

time period. However, in many respects, the potential for exposure at the North Claymont 

facility appears to be similar to that of the TCC facility. Like the North Claymont facility, the 

Texas City facility processed phosphate rock and produced relatively small quantities of 

yellowcake, but even these small quantities (i.e., about 300 pounds) are much greater than the 

quantities of uranium produced at the North Claymont facility (i.e., a few pounds).

A review of the TCC SEC petition evaluation report on the NIOSH website (NIOSH 2010) 

reveals that an SEC was granted for the TCC facility due to the inability to reconstruct radon 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

23 of 30

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.

exposures, but other exposures could be reconstructed. Specifically, the SEC petition evaluation 

report states the following:

Per EEOICPA and 42 C.F.R. § 83.13(c)(1), NIOSH has established that it does 

not have access to sufficient information to: (1) estimate the maximum radiation 

dose for every type of cancer for which radiation doses are reconstructed, that 

could have been incurred in plausible circumstances by any member of the class; 

or (2) estimate radiation doses of members of the class more precisely than an 

estimate of maximum dose. Information available from resources is not sufficient 

to document or estimate the maximum internal dose to members of the evaluated 

class under plausible circumstances during the specified period.

The NIOSH dose reconstruction feasibility findings for TCC are based on the 

following: 

• Principal sources of internal and external radiation dose for members of the 

proposed class included exposures to technologically enhanced concentrations of 

naturally-occurring uranium and decay products and naturally-occurring 

thorium and decay products present in phosphate rock.

• NIOSH finds there are insufficient data to estimate dose with sufficient accuracy 

from workers exposed to radon in the phosphoric acid plant at Texas City 

Chemicals. NIOSH has found no radon monitoring for the facility neither during 

the AEC period nor of the plant when it was in operation. Radon data is 

available from surveys of the site in the 1980s after the phosphate plant was shut 

down. NIOSH also determined that it lacks needed information to model radon 

exposures from processing phosphate rock; dose from processing phosphate rock 

is only applicable to EEOICPA dose reconstructions through September 1955. 

Although the source term is known, available information on the building size, 

layout, and process activities are insufficient to model maximum radon exposures 

with sufficient accuracy.

• NIOSH finds that it is feasible to bound occupational external dose from 

uranium extraction operations at Texas City Chemicals using source term and 

process information.

• NIOSH finds that it is feasible to bound occupational internal dose from 

uranium extraction operations based on data from uranium ore concentrate 

processing at other facilities.

• NIOSH finds that is feasible to bound occupational external and internal dose, 

other than radon, for phosphate workers exposed to technologically enhanced 

naturally occurring radioactive material using data from other phosphate 

facilities.
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

24 of 30

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.

For Method B, SC&A believes that the activities at the TCC facility, including our very limited 

knowledge of the facility, are in many ways analogous to the North Claymont facility. 

Accordingly, this first step in this blind DR takes guidance from the TCC SEC petition 

evaluation report with regard to DR protocols.

As described in Section 4.1 of NIOSH 2010, the DR protocols employed for TCC workers not 

covered by the SEC take guidance from site profiles from the following facilities and also from 

the following technical information bulletins and procedures:

Site Profiles

Technical Basis Document for Atomic Energy Operations at Blockson Chemical, Joliet, 

Illinois; OCAS-TKBS-0002, Rev. 02; November 21, 2007; SRDB Ref ID: 36611.

Basis for Development of an Exposure Matrix for Blockson Chemical Company, Joliet, 

Illinois; Period of Operation: March 1, 1951 through March 31, 1962, ORAUT-TKBS0002, Rev. 01; June 29, 2004; SRDB Ref ID: 19480.

Site Profiles for Atomic Weapons Employers that Refined Uranium and Thorium, 

Battelle-TBD-6001, Rev. F0; December 13, 2006; SRDB Ref ID: 30673.

Site Profiles for Atomic Weapons Employers that Refined Uranium and Thorium, 

Appendix BH – International Minerals and Chemical Corporation, Battelle-TBD-6001, 

App. BH, Rev. 0; July 16, 2007; SRDB Ref ID: 35365.

Technical Information Bulletins and Procedures 

OCAS-PR-004, Internal Procedures for the Evaluation of Special Exposure Cohort 

Petitions, Rev. 0, September 23, 2004; SRDB Ref ID 32022.

OCAS-TIB-009, Estimation of Ingestion Intakes, Rev. 0, April 13, 2004; SRDB Ref ID: 

22397.

ORAUT-OTIB-0006, Dose Reconstruction from Occupationally Related Diagnostic 

X-ray Procedures, Rev. 3 PC-1; December 21, 2005; SRDB Ref ID: 20220.

ORAUT-OTIB-0024, Estimation of Neutron Dose Rates from Alpha-Neutron Reactions 

in Uranium and Thorium Compounds, Rev. 00; April 7, 2005; SRDB Ref ID: 19445.

ORAUT-OTIB-0043, Characterization of Occupational Exposure to Radium and Radon 

Progeny during Recovery of Uranium from Phosphate Materials, Rev. 00; January 6, 

2006; SRDB Ref ID: 22596.

ORAUT-OTIB-0070, Dose Reconstruction During Residual Radioactivity Periods at 

Atomic Weapons Employer Facilities, Rev. 00, March 10, 2008; SRDB Ref ID 41603.
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

25 of 30

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.

II.5 RECONSTRUCTION OF INTERNAL DOSES USING A MAXIMIZING 

APPROACH

Section 7.2 of NIOSH 2010 presents the methods NIOSH has adopted to reconstruct internal 

doses at TCC. The internal doses include intakes associated with the processing of phosphate 

rock and also intakes associated with uranium recovery.

II.5.1 Internal Exposures from Phosphates

The primary data used by NIOSH in the assessment of internal doses at TCC was taken from a 

1998 report by the Florida Institute of Phosphate Research (FIPR) on dose at Florida phosphate 

plants that processed phosphate rock from central Florida, and a 1978 U.S. Environmental 

Protection Agency report of exposure to workers at an Idaho phosphate plant (FIPR 1998; EPA 

1978). A detailed discussion of the data is provided in Section 7.2 of NIOSH 2010 and is not 

repeated here. As explained in NIOSH 2010, the data used to reconstruct the TCC doses likely 

grossly overestimated the exposures, because the phosphate processing facilities from which the 

data were taken handled much larger quantities of phosphate rock than did TCC, as is also the 

case for the North Claymont facility. Some of the key assumptions are as follows:

To estimate intakes of airborne radioactivity at TCC from phosphate plant operations, the 

50.4 mg/m3 maximum measured dust concentration at the Idaho plant will be used as a 

bounding maximum average dust concentration.

A 2,500-hour work-year is assumed. Exposure to 50.4 mg/m3, at a breathing rate of 

1.2 m

3

/hr, results in an annual inhalation intake of 151.2 g of dust per year. The annual 

total dust inhalation intake is multiplied by the 95 pCi/g value for U-238 in Table 5-6 to 

determine an annual U-238 intake of 1.44 × 10+4 pCi. Conversion of the result into a 

calendar-day intake results in a 39 pCi/day chronic inhalation of U-238. The other 

radionuclides identified in the source term in Table 5-6 of NIOSH 2010 were calculated 

similarly and the inhalation intakes are provided in Table II-1.

Table II-1. Intakes from Operation of the Phosphate Plant

Radionuclides

Inhalation

pCi/day

Ingestion

pCi/day

U-238, Th-230, U-234, Ra-226, Pb-210, Po-210 39 0.79

Pa-231, Ac-227 1.8 0.036

Th-232, Ra-228, Th-228 1.3 0.026

Excerpted directly from Table 7.3 of the TCC SEC Petition Evaluation Report

II.5.2 Internal Exposures from Uranium Recovery

As explained in Section 7.2.2 of NIOSH 2010, inhalation intakes for workers engaged in 

uranium recovery work at TCC are estimated based on worker exposure to airborne uranium 

concentrates at other facilities. During the 10-year period from 1948 through 1958, the Health 

and Safety Laboratory (HASL) of the AEC conducted 60 complete evaluations of occupational 

hazards in seven uranium refining plants (AEC 1958). The evaluations consisted of 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

26 of 30

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.

measurements of more than 20,000 individual dust samples. These data are summarized in a 

paper published in November 1960 by the American Academy of Occupational Medicine 

entitled, “The Industrial Hygiene of Uranium Refining” (Christofano 1960). In this paper, data 

are presented for various uranium refining operations, including ore handling, ore sampling, 

uranium concentrate sampling, ore digestion, solvent extraction, denitration, oxide reduction, 

hydrofluorination, drum transfer operations, reduction to metal, recasting, fluorination, and scrap 

recovery.

Using data from these seven uranium refining plants, Table 7-4 of NIOSH 2010 presents the 

intake rates associated with uranium recovery operations. Table II-2 is excerpted directly from 

Table 7-4.

Table II-2. Intake Rates from Operation of the Uranium Recovery Plant

Radionuclides Uranium Plant Inhalation (pCi/week)

U-238, Th-230, U-234, Pb-210, Po-210 1,027

Pa-231, Ac-227 48.0

Ra-226 48.3

Th-232, Ra-228, Th-228 33.9

*Not included are intakes from the fertilizer plant because we are assuming that, since the Claymont facility was a 

uranium separations pilot plant, it was not involved in commerce-scale phosphate production.

Selectively excerpted from Table 7.4 of NIOSH 2010

An argument can be made that the intakes in Tables II.1 and II.2 cannot be applied to the North 

Claymont facility because it does not appear that it was a commercial phosphate production 

facility and the amounts of uranium produced were extremely small; i.e., these intakes are 

grossly unrealistic overestimates of the possible intakes at the North Claymont facility. The only 

possible rationalization that could support the use of the TCC protocols is that the airborne 

concentrations of the radionuclides at the North Claymont facility might have been comparable 

to those at larger facilities if the operations were confined to a small area. Under these 

conditions, it is possible that a small number of workers could have been exposed to comparable 

airborne radionuclide concentrations that existed in the larger facilities, at least for a relatively 

short period of time. In addition, since we are performing a bounding analysis, and if the 

analysis results in a POC less than 50%, the DR is compatible with the provisions of 42 CFR 

Part 82 as an efficiency method. At some time in the future, if an SEC is granted for this facility,

as was done for TCC due to an inability to reconstruct radon exposures, then this worker would 

be compensated.

An alternative strategy would be to prorate the doses based on the amount of uranium produced 

at the TCC Plant. Prorating would entail reducing the exposures derived using the protocols 

adopted in the TCC SEC Petition Evaluation report by about 100 (i.e., 300 pounds versus a few 

pounds of uranium), and perhaps reducing the duration of exposure from 15 to 20 years to 

5 years. Both strategies (prorating and not prorating) were considered in this blind DR, and 

resulted in POC greater than 50%, which could still be considered a gross overestimate of 

exposures.
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

27 of 30

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.

II.5.3 Radon Exposures

Page 85 and Appendix C of FIPR 1998 present a compendium of the radon concentration levels 

plus progeny associated with the phosphate industry, which were used as surrogate data for 

reconstructing radon exposures at the TCC facility. The report provides the following 

conclusions:

Radon Levels

Radon measurements made in this study using E-perm electret ion chambers were 

all well below the EPA 4 pCi/l guideline for residences, except for the rock 

tunnels. A total of 28 samples were collected as follows: mine area (11), 

rock (5), phosphoric acid (7), dry products (4), and shipping (1). The results can 

be found in Appendix C. The tremendous volume of industry-generated data 

already described was also scrutinized by the project team. The EPA uses an 

extremely conservative scenario of continuous home occupancy and exposure to 

derive this limit. Therefore, the application of this standard to far less occupancy 

time and an adult workforce leads to the conclusion that background exposures 

are not exceeded and an attributable dose above background does not usually 

occur.

Working Levels

The working level (WL) is a convenient one-parameter measure of the

concentration of radon progeny in air that can be employed as a measure of 

exposure hazard. One WL is defined as any combination of 218Po, 214Pb, 214Bi, 

and 214Po (the short-lived progeny of radon) in one liter of air, under ambient 

temperature and pressure, that will result in the ultimate emission of 1.3E+5 MeV 

of alpha particle energy. This is about the total amount of energy released over a 

long period of time by the short-lived daughters in equilibrium with 100 pCi of 

radon. Therefore, the conversion from pCi/l to WL, if one assumes equilibrium in 

the environment, is made by division by 100. However, most environments are 

not in equilibrium. The EPA assumes 50% equilibrium of daughters and thus the 

conversion of 4 pCi/l to 0.02 WL.

Some radon working levels were measured as support for the e-perm results. The 

raw results are tabulated in Appendix C. The levels were consistently low. Even 

in rock tunnels where the radon levels can be high, the working levels were less 

than 0.95 milliWL. This suggests that the tunnels are ventilated frequently 

enough so that equilibrium concentrations of radon progeny do not accumulate.

Based on these data, it is likely that no worker at the TCC facility experienced chronic radon 

exposures above 4 pCi/L, which translates to about 0.02 WL or about 12 m/yr × 0.02 WL = 

0.23 WLM/yr.

DR–Method B used the surrogate data employed at TCC for exposure to phosphate ore dust, 

separated uranium, and radon, to derive maximizing doses for the North Clayton facility and 

obtained a POC well in excess of 50% at the 99% confidence level. However, we felt that this 
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

28 of 30

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.

approach was a maximizing approach, and that compensation could not be awarded using such a 

method, for the reasons described above. As a result, we proceeded to use a minimizing 

approach to determine if the POC exceeded 50% even when using a minimizing approach.

II.6 DR USING A MINIMIZING APPROACH

The next step in our analysis of this unusual case is to use the minimizing approach, which, if 

found to result in doses that exceed a POC of 50%, would complete the DR, and compensation 

could be granted based on the provisions of Part 82 (k) (1).

In light of the above discussion and supporting analysis, Method B elected to derive a minimized 

dose to the lung and its associated POC by only considering radon exposures at a very low level,

i.e., 4 pCi/L, which translates to 0.235 WLM/yr at 50% equilibrium. Based on this analysis,

DR–Method B derives a POC of 64.1% at the 99% confidence level.

II.7 CONCLUSIONS

This analysis resulted in an unexpected result. In developing DR–Method B, SC&A made every 

effort to find surrogate data that might apply to this facility, but had difficulty finding data that

might apply. As a result, we elected to apply an efficiency approach, beginning with maximizing 

approach to determine if a POC of <50% could be derived. However, every effort at deriving a 

maximizing dose resulted in a POC >50%. Hence, Method B changed strategy and applied a 

minimizing approach; i.e., assume that the worker was only exposed to radon during the AWE 

period and at very low levels (i.e., 4 pCi/L). Surprisingly, this analysis also resulted in a POC 

>50%. Hence our analysis was completed, and it resulted in a conclusion that the worker should 

be compensated.

II.8 REFERENCES

42 CFR 82. Methods for Radiation Dose Reconstruction under the Energy Employees

Occupational Illness Compensation Program Act of 2000; Final Rule, Federal

Register/Vol.67, No. 85/Thursday, May 2, 2002, p. 22314.

AEC 1958. Environmental Hazards Associated with the Milling of Uranium Ore, A Summary 

Report, HASL-40, U.S. Atomic Energy Commission, New York Operations Office, June 4, 

1958.

Battelle 2006. Site Profiles for Atomic Weapons Employers that Refined Uranium and Thorium,

Battelle-TBD-6001, Rev. F0, December 13, 2006. (SRDB Ref ID: 30673)

Battelle 2007. Site Profiles for Atomic Weapons Employers that Refined Uranium and Thorium, 

Appendix BH – International Minerals and Chemical Corporation, Battelle-TBD-6001, App. 

BH, Rev. 0, July 16, 2007. (SRDB Ref ID: 35365)
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

29 of 30

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.

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

Environmental Health (Official Publication for the American Academy of Occupational 

Medicine), Vol. 1, No. 5; November 1960. (SRDB Ref ID: 15774)

DOE 1985. Formerly Utilized Sites Remedial Action Program, Elimination Report for Allied 

Chemical Corporations, Chemical Company, North Claymont, Delaware. U.S. Department of 

Energy. Appears to be dated December 31, 1985. (SRDB Ref ID: 14538)

EPA 1978. Radiological Surveys of Idaho Phosphate Ore Processing – The Wet Process Plant, 

U.S. Environmental Protection Agency (EPA), Technical Note ORP/LV-78-1, Las Vegas, 

Nevada, April 1978. (SRDB Ref ID 30886)

ERDA 1976. Radiological Surveys of Previously Used Division of Ray Materials Contractor 

Sites. Energy Research and Development Administration, Washington, DC. October 5, 1976. 

(SRDB Ref ID 016441)

FIPR 1998. Evaluation of Exposure to Technically Enhanced Naturally Occurring Radioactive 

Materials (TENORM) in the Phosphate Industry, Florida Institute of Phosphate Research, 

Publication No. 05-046-155, July 1998. (SRDB Ref ID 18076)

Monti, M.J., 2009. History of Honeywell Corporation – Allied Chemical and Dye Corporation, 

January 12, 2009. (SRDB Ref ID 98872)

Mott, W.E., 1977. Report of Findings: Allied Chemical Corporation Sites at North Claymont, 

Delaware; Marcus Hook, Pennsylvania, and Baltimore, Maryland. Report by W.E. Mott 

(Director), Division of Environmental Control Technology, HQ, Germantown, Maryland. 

December 12, 1977. (SRDB Ref ID 016503)

NIOSH 2010. SEC Petition Evaluation Report, Petition SEC-00088, Texas City Chemicals, Inc.

(TCC), Rev. 01, National Institute of Occupational Safety and Health, Cincinnati, Ohio. October 

18, 2010.

OCAS-PR-004. 2004. Internal Procedures for the Evaluation of Special Exposure Cohort 

Petitions, Rev. 0, NIOSH’s Office of Compensation Analyses and Support, Cincinnati, Ohio. 

September 23, 2004. (SRDB Ref ID 32022)

OCAS-TIB-009. 2004. Estimation of Ingestion Intakes, Rev. 0, NIOSH’s Office of 

Compensation Analyses and Support, Cincinnati, Ohio. April 13, 2004. (SRDB Ref ID: 22397)

OCAS-TKBS-0002. 2007. Technical Basis Document for Atomic Energy Operations at 

Blockson Chemical, Joliet, Illinois, Rev. 02, NIOSH’s Office of Compensation Analyses and 

Support, Cincinnati, Ohio, November 21, 2007. (SRDB Ref ID: 36611)

ORAUT-OTIB-0006. 2005. Dose Reconstruction from Occupationally Related Diagnostic 

X-ray Procedures, Rev. 3 PC-1, Oak Ridge Associated Universities Team Cincinnati, Ohio. 

December 21, 2005. (SRDB Ref ID: 20220)
Effective Date:

February 21, 2014

Revision No.

0 (Draft)

Document No. 

SCA-TR-BDR2014-CN[REDACTED]

Page No.

30 of 30

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.

ORAUT-OTIB-0024. 2005. Estimation of Neutron Dose Rates from Alpha-Neutron Reactions 

in Uranium and Thorium Compounds, Rev. 00; Oak Ridge Associated Universities Team 

Cincinnati, Ohio. April 7, 2005. (SRDB Ref ID: 19445)

ORAUT-TKBS-0002. 2004. Basis for Development of an Exposure Matrix for Blockson 

Chemical Company, Joliet, Illinois; Period of Operation: March 1, 1951 through March 31, 

1962, Rev. 01, Oak Ridge Associated Universities Team, Cincinnati, Ohio. June 29, 2004. 

(SRDB Ref ID: 19480)