Draft

ADVISORY BOARD ON

RADIATION AND WORKER HEALTH

National Institute for Occupational Safety and Health

SC&A REVIEW OF DCAS-TKBS-0009, REVISION 02 FOR 

HOOKER ELECTROCHEMICAL COMPANY 

Contract No. 211-2014-58081 

SCA-TR2016-SP006, Revision 0 

Prepared by

William Thurber, MS

SC&A, Inc.

1608 Spring Hill Road, Suite 400 

Vienna, Virginia, 22182 

Saliant, Inc.

5579 Catholic Church Road 

Jefferson, Maryland 21755 

June 2016 

DISCLAIMER

This is a working document provided by the Centers for Disease Control and Prevention (CDC) technical 

support contractor, SC&A for use in discussions with the National Institute for Occupational Safety and 

Health (NIOSH) and the Advisory Board on Radiation and Worker Health (ABRWH), including its 

Working Groups or Subcommittees. Documents produced by SC&A, such as memorandum, white paper, 

draft or working documents are not final NIOSH or ABRWH products or positions, unless specifically 

marked as such. This document prepared by SC&A represents its preliminary evaluation on technical 

issues.

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

2 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution. 

SC&A, INC.: Technical Support for the Advisory Board on Radiation and Worker 

Health Review of NIOSH Dose Reconstruction Program

DOCUMENT TITLE: 

SC&A Review of DCAS-TKBS-0009, Revision 02 for Hooker 

Electrochemical Company

DOCUMENT NUMBER/

DESCRIPTION:

SCA-TR-2016-SP006 

REVISION NO.: 0 (Draft)

SUPERSEDES: N/A

EFFECTIVE DATE: June 28, 2016

TASK MANAGER: William Thurber, MS [signature on file]

PROJECT MANAGER: John Stiver, MS, CHP [signature on file]

DOCUMENT 

REVIEWER(S): John Mauro, PhD, CHP [signature on file] 

Record of Revisions

Revision 

Number

Effective 

Date Description of Revision

0 (Draft) 06/28/2016 Initial issue
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

3 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution. 

TABLE OF CONTENTS

Abbreviations and Acronyms ......................................................................................................... 4

1.0 Introduction......................................................................................................................... 5

2.0 Background ......................................................................................................................... 5

3.0 Review of SC&A Findings................................................................................................. 6

3.1 Finding 1 ................................................................................................................. 6

3.2 Finding 2 ................................................................................................................. 7

3.3 Finding 3 ................................................................................................................. 7

3.4 Finding 4 ................................................................................................................. 8

3.5 Finding 5 ................................................................................................................. 9

3.6 Finding 6 ............................................................................................................... 10

4.0 References......................................................................................................................... 10
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

4 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution. 

ABBREVIATIONS AND ACRONYMS

ABRWH Advisory Board on Radiation and Worker Health 

DCAS Division of Compensation Analysis and Support 

ER evaluation report 

dpm disintegrations per minute

dpm/hr disintegrations per minute per hour 

dpm/m2 disintegrations per minute per square meter

dpm/m3 disintegrations per minute per cubic meter 

Electromet Electro Metallurgical Company

HCl hydrochloric acid

Hooker Hooker Electrochemical Company 

MCNP Monte Carlo N-Particle

MED Manhattan Engineer District

MgF2 magnesium fluoride

mr/hr milliroentgen per hour 

mrad/hr millirad per hour 

mrem/hr millirem per hour

NIOSH National Institute for Occupational Safety and Health

SEC Special Exposure Cohort 

SRDB Site Research Database

TBD technical basis document

U uranium 

UF4 uranium tetraflouride

URAWE Uranium Refining Atomic Weapons Employers 
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

5 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

1.0 INTRODUCTION

In April 2016, SC&A was tasked (Katz 2016) to review the revised Technical Basis Document

for the Hooker Electrochemical Company, DCAS-TKBS-0009, Revision 02 (NIOSH 2015b; 

“TKBS-0009”) and determine whether it addressed SC&A’s 2013 findings about Revision 01 of 

this technical basis document (TBD) (SC&A 2013). This report presents SC&A’s review of 

TKBS-0009, Revision 02. SC&A 2013 had identified six findings based on its review. As 

discussed here, SC&A recommends that four of the findings be closed, but that additional 

information is required on two of the findings.

2.0 BACKGROUND

The Hooker Electrochemical Company (Hooker) in Niagara Falls, New York, processed socalled “C-2 slag” from July 11, 1944, through January 15, 1946 (NIOSH 2011b). The operations 

at Hooker involved the treatment of C-2 slag from the nearby Electro Metallurgical Company 

(Electromet) with hydrochloric acid (HCl) to increase the slag’s uranium content. The C-2 slag 

from Electromet was a byproduct of the bomb reduction process in which uranium tetrafluoride 

(UF4) was exothermically reacted with magnesium metal to produce uranium metal. Dolomite 

was used as the refractory liner in the steel bomb at that point in time (NIOSH 2011b). After 

1948, recycled magnesium fluoride (MgF2) was used as the liner. The dolomite was high-fired or 

fused, resulting in a product with the approximate formula CaO∙MgO. The HCl was excess acid 

produced at Hooker under an Atomic Energy Commission contract as a byproduct from the nonradioactive P-45 process.

In 2007, the National Institute for Occupational Safety and Health (NIOSH) issued the original 

site profile for Hooker (NIOSH 2007) as Appendix AA to Battelle-TBD-6001, Site Profiles for 

Atomic Weapons Employers that Refine Uranium and Thorium (NIOSH 2006; “TBD-6001”). As 

an appendix to TBD-6001, the Hooker site profile relied heavily on the parent document for dose 

reconstruction guidance. Based on a May 2010 request by the Advisory Board on Radiation and 

Worker Health (ABRWH), SC&A performed a review of Appendix AA and reported 10 findings 

(SC&A 2010). Several of the findings related to TBD-6001, upon which much of Appendix AA 

was based. TBD-6001 was subsequently cancelled by NIOSH, and alternate modeling 

approaches were used in revising the Hooker site profile.

Subsequently, at the TBD-6001 Work Group Meeting held in Cincinnati, Ohio, on November 4, 

2010, the Work Group requested SC&A to prepare a focused review of the Hooker petition 

evaluation report (ER) on Petition SEC-00141, prepared by NIOSH (NIOSH 2010). Since the 

ER contained new information developed since Appendix AA was issued in 2007 (Battelle 

2007), the Work Group felt that a focused review of the new information was needed. In 

response to this tasking, SC&A provided a focused review of the ER in January 2011 (SC&A 

2011) in which SC&A made nine findings.

After the 2010 SC&A review of Appendix AA, NIOSH converted it to a stand-alone site profile 

or TBD published on April 4, 2011 (NIOSH 2011a) and issued a revision to that document on 

June 17, 2011 (NIOSH 2011b).
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

6 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

According to NIOSH, the following changes were made in NIOSH 2011a:

Changes Battelle-TBD-6001 Appendix to a stand- alone document. Revises dose 

models to eliminate dependence on Battelle-TBD-6001. Provides more detailed 

description of dose models. Incorporate review comments.

In Revision 01 of the Hooker TBD, NIOSH described the changes as follows (NIOSH 2011b):

Revision initiated to correct errors in Tables 2, 3, and 6 [of NIOSH 2011a]. 

Renumber Tables after Table 4. Added language on page 10 to indicate 95th 

percentile of the airborne values was used. Corrected typographical error on 

pages 7 and 14.

At the January 2013 meeting of the Procedures Work Group, SC&A was authorized to conduct a 

critical review of NIOSH 2011b. During that review, SC&A uncovered some information that 

had not been utilized in prior reviews of Hooker. This new information dealt with quantities and 

uranium content of the C-2 slag. The critical review resulted in six findings, which are 

documented in SC&A 2013 (SCA-TR-SP2013-0034).

NIOSH issued Revision 02 to the Hooker site profile in December 2015 (NIOSH 2015b) with 

the stated purpose:

Revision initiated to include information about a Special Exposure Cohort 

designation for Hooker. Revision also incorporates changes due to new 

information describing the operations at Hooker.

As noted above, this report reviews DCAS-TKBS-0009, Revision 02 and makes a determination 

as to whether SC&A’s 2013 findings were satisfactorily addressed.

3.0 REVIEW OF SC&A FINDINGS

3.1 FINDING 1

Finding 1. NIOSH should review the assumptions regarding the composition slag 

and the outgoing concentrate.

SC&A 2013 states (page 10):

There is some uncertainty as to the uranium content and composition of the slag. 

...the uranium content is stated on page 29 of MED 1944 as 1%. However, on 

page 30 of MED 1944, it is stated that, “slag is concentrated from about 1 lb to 

5 or 10 lb by weight.’ ́ If the barrel [of incoming slag] contained 1 lb of uranium 

in 500 lb of slag, then the initial composition would be 0.2% (as assumed in 

NIOSH 2010, NIOSH 2011 a and b, and SC&A 2010) not1% as stated in MED 

1944 (p. 29);
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

7 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

Therefore, SC&A 2013 concludes the following (page 12):

Based on the information presented here [SC&A 2013], it is plausible to assume 

that the concentration of uranium in the incoming slag and in the resultant 

concentrate is at least five times higher than assumed in the TBD.

Another factor to consider is estimating the external dose from slag handling. The 

+20 mesh fraction, which was not subject to acid digestion but did require 

handling, amounts to about 20% of the slag mass and contains 9% U (Thomas 

1944). The contribution from this higher uranium content material needs to be 

included in the external exposure estimate.

In response to the new information provided in SC&A 2013, NIOSH revised the suppositions 

about slag composition to assume that the fines in the slag (80% of the total) contained 0.84% 

uranium (U), while the lumps (20% of the total) contained 9.87% U, resulting in an average 

concentration in the slag of 2.65% U.

SC&A is satisfied, that, with the revised slag and concentrate concentrations, the concerns 

regarding Finding 1 have been adequately addressed and proposes that the finding be closed.

3.2 FINDING 2

Finding 2: NIOSH should re-examine its position that external exposures were 

based on slag input to the leaching process of 10 tons per month. It is possible 

that external exposures are understated by a factor of about 5.

As described on page 13 of SC&A 2013:

Information in Thomas 1944 supports the idea that the input to the Hooker 

process was more than 10 tons per month. Thomas notes that the availability of 

HCl at Hooker was sufficient to concentrate 65 to 80 tons per month. In addition, 

equipment was sized for an 80-ton per month acid leaching plant at Hooker.

In Revision 02 to DCAS-TKBS-0009 (NIOSH 2015b), NIOSH examined three production 

scenarios based on differing interpretations of the available information. NIOSH concluded that 

Scenario 3, involving processing 89 tons of slag monthly to produce 10.4 tons of wet 

concentrates, was most consistent with the available information. We concur with NIOSH that 

Scenario 3 is the best fit for the somewhat ambiguous information. The revised analysis satisfies 

SC&A’s concerns about external exposure from slag handling and we propose that this finding 

be closed.

3.3 FINDING 3

Finding 3: The basis for assuming that internal exposure from slag dust occurred 

5% of the time needs to be re-examined as does the assumption that the 

concentrate contained 2% U. It appears that the exposure time is understated by 

about a factor of five and the amount of uranium in the concentrate is understated 

by at least a factor of 2.5.
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

8 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution. 

As shown in Table 1 of TKBS-0009, Revision 02, NIOSH has now assumed that the concentrate 

contained 9.87% U wet basis or 5.87% U dry basis. Use of these revised assumptions satisfies 

SC&A’s concerns regarding uranium concentration in the concentrates. Additionally, NIOSH 

assumed in Revision 02 of TKBS-0009 that slag handling would occur 2 hours per work day or 

25% of the time, rather than 5% of the time previously assumed. Based on these revisions, we 

propose that Finding 3 be closed. 

3.4 FINDING 4

Finding 4: NIOSH should review the ingestion intake to ensure that it is 

calculated in a manner consistent with calculation of inhalation intake. 

SC&A recognizes that workers at Hooker have been added to the Special Exposure Cohort 

(SEC) for the operational period (November 1, 1945, through October 11, 1976) based on lack of 

air concentration data at the site for all of the operational period. However, inhalation and 

ingestion intakes are needed to assess operational exposures resulting in cancers not specified 

under the Energy Employees Occupational Illness Compensation Program Act of 2000 

regulations and to calculate inhalation and ingestion exposures during the residual period. 

NIOSH states that inhalation intakes during the residual period are 3.2 disintegrations per minute 

(dpm) per calendar-day, presumably based on resuspended surface contamination of 0.404 

dpm/m3

, a breathing rate of 1.2 m3/hr, an 8-hour work day, and 300 work days per 365 calendar 

days (NIOSH 2015b, Table 7). However, NIOSH does not address ingestion exposures during 

the residual period.1

 Ingestion during the residual period has been the subject of recent 

deliberations by the Uranium Refining Atomic Weapons Employers (URAWE) Work Group 

(NIOSH 2015c), and it was determined that the procedures for the operational period as 

described in OCAS-TIB-009, Estimation of Ingestion Intakes (OCAS 2004), were not 

appropriate for the residual period. Ingestion exposures are apparently higher than inhalation 

exposures during the residual period because of an increase of hand-to-mouth transfer relative to 

inhalation in low-dust environments. For example, NIOSH showed, for the DuPont Deepwater 

site, that ingestion during the residual period was 100 times the inhalation intake (NIOSH 2015a, 

Section 6.0). 

1 While ingestion is not mentioned in the text of TKBS-0009, Revision 02, OCAS-TIB-009 (OCAS 2004) is cited in 

the list of references but not linked to the text.

NIOSH states in Section 4.1 of TKBS-0009, Revision 02 that the airborne concentration is used 

in the residual contamination section to calculate the surface contamination and the resulting 

internal and external doses. Based on this statement, the surface concentration based on 30 days 

of continuous deposition is: 

208 dpm/m3 (avg. air conc.) × 0.00075 m/s × 3,600 sec/hr × 24 hr/day × 30 days = 404,352 

dpm/m2

This is a very conservative approach, since it assumes 24-hour-per-day deposition and no 

degradation of surface contamination over time. As noted above, using this limiting surface 

concentration, the inhalation intake is 3.2 dpm per calendar day. Using the approach from 

 
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

9 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

DCAS-TKBS-0006 (NIOSH 2015a) and the hand-to-mouth transfer factor from NUREG/CR5512 (NRC 1992) to calculate the ingestion intake results in the following: 

1.1E-04 m2

/hr × 404,352 dpm/m2 = 44.5 dpm/hr

While SC&A expects that ingestion exposures will be small, they should be addressed for 

completeness in TKBS-0009.

3.5 FINDING 5

Finding 5: NIOSH should confirm that the correct units of measure are cited in 

Tables 2 and 3. [Tables 3 and 4 in NIOSH 2015b]

In its prior review, SC&A noted that the photon exposure was expressed differently in Tables 2 

and 3 (SC&A 2013). Both tables include the phrase “External Dose Rate” in the titles, but the 

units of measure in Table 2 (now Table 3) are mr/hr while the units in Table 3 (now Table 4) are 

mrem/hr. Based on the information provided in the text of Revisions 1 (NIOSH 2011b) and 2 

(NIOSH 2015b) of TKBS-0009, SC&A concluded that the units of measure in Table 2 should be 

mrem/hr and noted that the distinction was important because it can have a significant impact 

when selecting organ dose conversion factors from OCAS-IG-001, Revision 03, External Dose 

Reconstruction Implementation Guidelines (OCAS 2007). 

We also note that, in Table 2, the beta dose is expressed in units of mrad/hr, while in Table 3 the 

units are in mrem/hr. SC&A recognizes that, for beta dose, the units are equivalent but, in the 

interests of clarity, consistent units should be used.

Since the cited tables were not revised between Revision 01 (NIOSH 2011b) and Revision 02

(NIOSH 2015b), SC&A believes that Finding 5 has not been resolved.

During the current review, SC&A uncovered some concerns regarding Table 5 in Revision 02

(NIOSH 2015b). The dose rates in the third column of that table are not correct. The correct 

value of the exposure (not dose) rate should be 2.74E-04 mr/hr (6.79E-10 mr/hr per dpm/m2 × 

404,314 dpm/m2). Based on a 6-day work week, 50 weeks per year, the photon exposure rate 

would be 0.659 mr/yr, which agrees with the value in Table 6. So, the error in Table 5 was not 

propagated. Similarly, the beta dose rate in Table 5 should be 2.44E-02 mrem/hr (58.6 mrem/yr),

not 1.669 E-02 mrem/yr. Again, the error in the Table 5 beta dose rate was not propagated into 

Table 6.

We note that the Monte Carlo N-Particle (MCNP) surface contamination conversion factors in 

Table 5 (NIOSH 2015b) were based on the dose rate (or exposure rate) at 1 foot from the 

contaminated surface. This is in contrast to the methodology in Revision 01 of Batelle-TBD6000, Site Profiles for Atomic Weapons Employers that Worked Uranium Metal (NIOSH 2011c; 

“TBD-6000”), where the dose rate was determined at 1 meter from the contaminated surface. 

While the calculational approach for Hooker is more claimant favorable, it is not apparent why 

the already vetted values from TBD-6000 were not used.
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

10 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

We also note an apparent error in Table 7 of TKBS-0009, Revision 02. It appears that the photon 

doses for the residual period are incorrect. The stated photon doses are actually beta doses to the 

skin.

3.6 FINDING 6

Finding 6: NIOSH should review the units of measure for the photon dose 

conversion factors in Table 4 [now Table 5] and determine if they are correct. If 

they are correct, the companion text needs to be revised to discuss exposure rates 

rather than dose rates.

Table 4 (NIOSH 2015b) listed the photon conversion factor as 6.79E-10 mr/hr per dpm alpha/m2

and the dose rate as 1.90E-04 mr/hr. If the units are correctly stated, then the table and the text 

need to refer to the photon parameters as exposure rates. This remains to be clarified.

4.0 REFERENCES

Katz 2016. E-mail from Ted Katz (CDC/NIOSH/OD) dated April 14, 2016, Subject: URAWE 

WG Items. 

MED 1944. Medical Section – Manhattan District, Data Sheets for Industrial Hazard Rating, 

Manhattan Engineer District. 1944. [SRDB Ref. ID 16323]

NIOSH 2006. Site Profiles for Atomic Weapons Employers that Refine Uranium and Thorium. 

Battelle-TBD-6001, Revision F0. December 13, 2006.

NIOSH 2007. Site Profiles for Atomic Weapons Employers that Refine Uranium and Thorium –

Appendix AA, Hooker Electrochemical Company, Battelle-TBD-6001, Appendix AA, 

Revision 00. June 15, 2007.

NIOSH 2010. SEC Petition Evaluation Report, Petition SEC-00141: Hooker Electrochemical,

National Institute for Occupational Safety and Health. May 3, 2010.

NIOSH 2011a. Technical Basis Document for the Hooker Electrochemical Company, DCASTKBS-0009, Revision 00, Division of Compensation Analysis and Support, National Institute for 

Occupational Safety and Health, Cincinnati, Ohio. April 4, 2011.

NIOSH 2011b. Technical Basis Document for the Hooker Electrochemical Company, DCASTKBS-0009, Revision 1, Division of Compensation Analysis and Support, National Institute for 

Occupational Safety and Health, Cincinnati, Ohio. June 17, 2011.

NIOSH 2011c. Site Profiles for Atomic Weapons Employers that Worked Uranium Metal,

Battelle-TBD-6000, Revision 01, National Institute for Occupational Safety and Health. June 17, 

2011.

NIOSH 2015a. Technical Basis Document for DuPont Deepwater Works, Deepwater New 

Jersey, DCAS-TKBS-0006, Revision 02, Division of Compensation Analysis and Support, 

National Institute for Occupational Safety and Health, Cincinnati, Ohio. March 20, 2015.
Effective Date:

06/28/2016

Revision No.

0 (Draft)

Document No./Description:

SCA-TR-2016-SP006

Page No.

11 of 11

NOTICE: This report has been reviewed to identify and redact any information that is protected by the 

Privacy Act 5 U.S.C. § 552a and has been cleared for distribution.

NIOSH 2015b. Technical Basis Document for the Hooker Electrochemical Company, DCASTKBS-0009, Revision 02, Division of Compensation Analysis and Support, National Institute for 

Occupational Safety and Health, Cincinnati, Ohio. December 8, 2015.

NIOSH 2015c. Transcript of the Uranium Refining Atomic Weapons Employers Work Group, 

National Institute for Occupational Safety and Health, January 22, 2015.

NRC 1992. Residual Radioactive Contamination from Decommissioning, NUREG/CR-5512, 

Volume 1, U.S. Nuclear Regulatory Commission, Washington, DC. October 1992. [SRDB 

Ref. ID 23558]

OCAS 2004. Estimation of Ingestion Intakes. OCAS-TIB-009, Revision 00, Office of 

Compensation Analysis and Support, National Institute for Occupational Safety and Health, 

Cincinnati, Ohio. April 13, 2004.

OCAS 2007. External Dose Reconstruction Implementation Guidelines, OCAS-IG-001, 

Revision 03, Office of Compensation Analysis and Support, National Institute for Occupational 

Safety and Health, Cincinnati, Ohio. April 13, 2007.

SC&A 2010. Review of NIOSH Site Profile for Hooker Electrochemical Company, BattelleTBD-6001, Appendix AA, SCA-TR-SP2010-0034, SC&A, Inc., Vienna, Virginia. September 9,

2010.

SC&A 2011. A Focused Review of the Hooker Electrochemical Company Petition Evaluation 

Report for SEC-00141, SCA-SEC-2011-0018, Revision 0, SC&A, Inc., Vienna, Virginia. 

January 19, 2011.

SC&A 2013. Review of NIOSH Technical Basis Document for the Hooker Electrochemical 

Company, DCAS-TKBS-0009, SCA-TR-SP2013-0034, Revision 0. SC&A, Inc., Vienna, 

Virginia. March 28, 2013.

Thomas 1944. W.G. Thomas, Technical Report – Concentration of C-2 Slag, M-4562, United 

States Atomic Energy Commission. February 17, 1944. [SRDB Ref. ID 127827]