SEC Petition Evaluation Report 

Petition SEC-00079 

Report Rev #: Addendum 1 Report Submittal Date: 8/06/2007

Subject Expert(s): James Mahathy 

Site Expert(s): N/A 

Petitioner Administrative Summary 

Petition Under Evaluation 

Petition # Petition 

Type 

Petition A 

Receipt Date DOE/AWE Facility Name 

SEC-00079 83.14 November 28, 2006 Dow Chemical Company (Madison Site) 

Proposed Class Definition 

All Atomic Weapons Employer employees who were monitored, or should have been monitored, for 

exposure to thorium radionuclides while working at the Dow Chemical Company site in Madison, 

Illinois, for a number of work days aggregating at least 250 work days from January 1, 1957 through 

December 31, 1960, or in combination with work days within the parameters established for one or 

more other classes of employees in the Special Exposure Cohort.

Related Petition Summary Information 

SEC Petition Tracking #(s) Petition Type DOE/AWE Facility Name Petition Status 

NONE 

Related Evaluation Report Information 

Report Title DOE/AWE Facility Name 

SEC Petition Evaluation Report, SEC-00079 Dow (Madison Site) 

Peer Review Completed By: [Signature on file] 08/06/2007 

 S. Hinnefeld Date 

SEC Petition Evaluation Reviewed By: [Signature on file] 08/06/2007 

 J. W. Neton Date 

SEC Evaluation Approved By: [Signature on file] 08/13/2007 

 Larry Elliott Date 
SEC-00079 Addendum 08-06-07 Dow Madison

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SEC-00079 Addendum 08-06-07 Dow Madison

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 Addendum to Dow Madison (SEC-00079) Special Exposure Cohort 

Evaluation Report 

Shortly before NIOSH’s presentation of the Special Exposure Cohort (SEC) Petition Evaluation 

Report (ER) for the Dow Madison site (SEC-00079) at the May 5, 2007 Advisory Board on Radiation 

and Worker Health (The Board) meeting, NIOSH received from Dow Chemical Company (Dow) an 

additional 72 digital file folders (676 pages) that were related to the operations at its former Madison 

site. Because of the short time period, NIOSH was not able to consider those documents in 

preparation of the ER. This supplement to the Dow Madison ER reviews the newly available 

documents and evaluates the impact of the information on the proposed class designation. 

NIOSH has reviewed the additional documentation provided by Dow and concluded that the 

documentation does not provide sufficient additional information regarding potential internal thorium 

dose to workers at the Madison site during the covered period of the SEC, which would result in a 

change to the initial conclusion that it is not feasible to reconstruct those doses. The additional 

documentation does include sufficient information to provide a bounding reconstruction of external 

dose resulting from thorium. 

Table 1 (attached) identifies the documents that were provided in the additional submittal from Dow. 

NIOSH has reviewed the list of documents to determine those that were not available for preparation 

of the ER. Each new document was reviewed to identify information relevant to dose reconstruction 

such as general radiation monitoring data, air sample information, personal monitoring data, types of 

activities, and time frames. Based on this review, it was determined if this new information allowed 

for the completion of dose reconstructions for individual members of the class with sufficient 

accuracy. Table 2 (attached) consolidates all the data from the various sampling and monitoring 

events reported in the documents. 

Most of the newly provided documents are related to thorium processing at the Madison site and 

contain some additional dose rate and air sample data for thorium. The documents contain no new 

information regarding uranium. 

Below are discussions of the impact of the newly available documents on the following sections of the 

ER. The particular source documents can be identified in Tables 1 and 2. 

Petition Evaluation Report Summary 

NIOSH-Proposed Class Definition

NIOSH did not find any information in the newly provided documentation that would have any effect 

on the definition of the class or on any individual’s qualification as a member of the class. This 

addendum will be provided to the Department of Labor (DOL) to assist it in implementing the current 

class definition. 

 

Feasibility of Dose Reconstruction
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The newly provided documentation does not contain any personnel bioassay monitoring results. The 

documents also do not contain any external personnel monitoring data for workers at the Madison site; 

however, they do include film badge results for a list of job titles related to magnesium-thorium alloy 

processing for workers at another Dow facility (Bay City, MI) during a 13-day period. Also included 

in the documents are a number of reports, papers, and memos presenting the results of several 

workplace sampling campaigns during operations at the Madison site, which included worker 

breathing zone samples, work area air samples, and external dose rate measurements. The breathing 

zone samples and work area air samples are essentially the same types of data that were initially 

available and which the SEC ER is based. Although these measurements provide a somewhat fuller 

understanding of the radiation environment to which the Dow Madison workers were exposed, 

NIOSH still lacks necessary information to complete reconstructions of the internal dose due to 

thorium for individual members of the class with sufficient accuracy. The additional direct radiation 

readings , coupled with film badge results from a facility performing the same operations, provide a 

much more complete understanding of potential exposures to external radiation from thorium. 

4.1 Operations Description 

The list of magnesium-thorium alloys which Dow Madison commercially produced should be revised 

from those listed in the ER (HK-31, HK-61, HM-21, and AZ-31). From the available documents the 

list of Mg-Th alloys would be: HK11(?), HK31*, HM21*, HM31*, HZ32A, ZH62A based on the 

following: 

A 1/10/56 IH Sample Record (TDCC 000001) shows a surface radiation measurement for HK11, but 

there is no mention of it anywhere else. Per Dow magnesium product standard spec sheet A-I-2, July 

1, 1968 (TDCC 000443, 536, 554) only three alloys (at that time) contained Th – they were HK31A, 

HM21A, and HM31A. Alloy AZ-31 is listed as not containing Th (HK-61 was not listed). Also, in a 

6/19/57 paper by Dow scientist L. Silverstein (TDCC 000058) thorium-containing alloys were 

identified as HK31A, HM21XA, HZ32A, ZH62A, and HM31XA. 

* Alloy designations sometimes have additional letter suffixes, e.g., HM31/HM31A/HM31XA. 

The description of the alloying process should be revised. The addition of thorium to the molten 

magnesium involved (Per Affidavit No. 2) heating up a basket in the molten metal (Mg) first, then 

dumping thorium in the form of pellets into the basket, and then getting it under the surface of the 

molten Mg as quickly as possible so that it wouldn’t ignite. The process did not involve pouring 

molten thorium into the basket as stated in the PER. 

4.4 Site Locations Associated with Radiological Operations 

Additional areas where thorium materials were handled were identified in the newly provided 

documents. Besides Bldg. 6, other buildings with Th activities included: thorium fluoride storage in 

Bldg. 376 and hardener casting in Bldg. 152. 

4.5 Job Descriptions Affected by Radiological Operations 

Among the newly provided documents is a report of 27 film badge readings (for a 13 day period) for 

20 specific jobs (pour off, knockout, sandblast, band saw, chipper, machine trim, inspection, pickler, 
SEC-00079 Addendum 08-06-07 Dow Madison

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rotary file, buffer, heat treat, Wheelabrator, touchup, X-ray, fixture, shipping, metal reclamation) 

associated with HK-31 casting production at Bay City, which was another facility operated by Dow 

(TDCC 000362). The list of jobs is fairly descriptive and specific, and probably similar to those 

which would have been performed during thorium operations at the Madison site, but it is not known 

how complete or how representative of the Madison site this list is, and therefore it is still not possible 

to use job descriptions to define the proposed class. 

5.0 Summary of Available Monitoring Data for the Proposed Class 

The newly provided documents contain data from a number of additional sampling events/campaigns 

not available for the ER. The following table summarizes data found in the newly provided 

documents that were not available for consideration in the original ER. 

TYPE NO. OF EVENTS* NO. OF SAMPLES 

Film Badge (Bay City) 1 27 

BZ Air Samples 5 >30 

Area Air Samples >10 >97 

Dose Rate 

Measurement/Surveys 

5 >81 

*Some sample dates precede the covered period, but cover the same types of operations 

5.1 Internal Personnel Monitoring Data 

The newly provided documents do not contain any personnel bioassay monitoring data for Dow 

Madison site employees. There are reports from five air sampling events where a total of over 30 

worker breathing zone air samples were obtained during various Mg-Th alloy production operations.

5.2 External Personnel Monitoring Data 

See 4.5 above. The film badge results for jobs at the Bay City site ranged from <10 mr to 75 mr for 

the 13 day monitoring period. It is not known how representative the list may be of jobs at the 

Madison site, nor is it known how similar the plant and equipment layout may have been at the two 

sites, and so it is not realistic to assume the results can be applied to workers at the Madison site. 

 

5.3 Workplace Monitoring Data 

The newly provided documents contain air monitoring results for thorium airborne contamination 

collected during at least ten sampling campaigns totaling almost 100 samples. These cover various 

operations and situations including mechanical operations, alloying operations, and alloy fires. 

The documents also include results of several surveys of dose rate measurements in areas where 

thorium work was being conducted. Five surveys totaling over 80 readings were performed during 

the covered period or near that time. 

5.4 Radiological Source Term Data 
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Several documents indicate different quantities of thorium which could have been received by Dow 

Madison. The ER cites an Atomic Energy Commission (AEC) inspection report that stated 80 

English tons had been received through July 1, 1960. The amount cited (80 tons) = 160,000# total for 

approx. 4 years = 40,000# per year. 

There are other indicators of what the potential source term may have been. Dow’s 1956 application 

(and subsequent annual requests for renewal) for an AEC license covers 135,000# Th metal and 

30,000# Th fluoride or oxide per year, however this covered multiple sites (Midland, MI; Bay City, 

MI; Madison, IL; and Freeport, TX) and it doesn’t delineate how much might be handled at each site. 

Also, TDCC 000045 includes an estimate of external exposure based upon 2-3 casting runs per year of 

100,000# of 3% alloy, which would equal 9000# of Th per year.

6.1 Feasibility of Estimating Internal Exposures 

As stated in Section 5.1, no personnel bioassay monitoring results for thorium were included in the 

newly provided documents. A number of workplace and breathing zone thorium air monitoring 

results were found. Even with the addition of these data it is not feasible to reconstruct with sufficient 

accuracy the internal doses that may have resulted from potential exposure to thorium isotopes. 

 

6.2 Feasibility of Estimating External Exposures 

Based on the available dose rate measurements and survey results, a bounding reconstruction of 

external dose resulting from exposure to thorium is feasible. 

7.0 Summary of Feasibility Findings for Petition SEC-00079 

The newly provided documents contain no additional information or data that would change the 

conclusions of the ER in regard to reconstructing doses from uranium or from medical x-rays. 

Additional dose rate data is sufficient to support a bounding reconstruction of external thorium dose. 

No personnel bioassay data was included in the documents, and the additional breathing zone thorium 

air samples are not sufficient to support reconstruction of internal thorium exposures. 
SEC Petition Evaluation Report for Petition SEC-00079 

TABLE 1 - REVIEW OF DOCUMENTS RECEIVED FROM DOW 5/17/07 Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

TDCC 000001 1/10/56 

No author 

Industrial Hygiene Sample Record for “Madison” Bldg. 

Surface and up to 7’ 

β and 

γ

readings on slabs of HK-31 alloy metal, packaged sheets, HK11 and HM21 alloys 1/10/56 (Predates covered period). 

Additional extmeasurements metals. 

TDCC 000005 8/23/56 

L. Silverstein (Dow Midland) 

Paper: Determination of the Radioactivity Hazard Encountered in Alloying and Casting HM21 Alloy at the Madison Division 

Surface readings on Th pellets and HM21 scrap; Workplace and BZ air samples during 35,000# HM-21 alloying campaign on 7/22-23/56 (Predates covered period). 

External rad rpellets and HMcontact and nodistance 

TDCC 000014 9/18/56 

No author 

Industrial Hygiene Sample Record 

Area air samples during HM21 & HK-31 Alloying & Casting on 9/17-18/56 (Predates covered period). 

Area air sampalloying and c
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

TDCC 000019 8/3/56 

L. Silverstein (Dow Midland) 

Paper: Health Hazards from Radioactive Decay Products from Th During Melting, Chemical Milling and Burning of Th Containing Mg Alloys 

Workplace air samples during Mg-Th hardener production, melting, chemical milling (Bay City), ThF4 storage, and a fire involving 4# of HK31 shavings in the period 2/14/56 to 5/8/56 (Predates covered period). 

Th air concenBldg. 152, 376City, MI; Incident: Fire shavings in Bl5/8/56 

TDCC 000031 12/56 

L. Silverstein (Dow Midland) 

Paper: Industrial Health Experience in Fabrication & Production of MgTh Alloys 

Rad levels on contact and 1 foot from HK-31A, and BZ air samples during grinding, filing, buffing, sawing, welding, and acid pickling (no date, but report predates covered period) 

Welding air saTDCC 000058 000418) 

TDCC 000043 1/10/57 

L. Silverstein (Dow Midland) 

Letter to D. Levy (Dow) 

Storage practices to meet lower annual exposure limit 

No 

TDCC 000044 2/26/57 

D. Levy (Dow Madison) 

Memo to W. Saunders (Dow Madison) 

Memo to use Th pellets & hardener on 1st in-1st out basis 

No 

TDCC 000045 3/8/57 

D. Levy (Dow Madison) 

Letter to G. Ansel (Dow Madison) 

Rad survey of Pot room on 2/27/57; Estimate of external exposures during Th pellet and hardener alloying based on 2-3 casting runs per year of 100,000# each (@ 3% Th = 

Rad measuremestimate of exduring alloyinBasis of estimruns per year each) gives in
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

3000# x 3 runs = 9000#/yr) actual product

the time 

TDCC 000047 3/14/57 

C. Mitchell (Dow Madison) 

Memo to H. Hoyle (Dow) with lab results 

BZ air samples during sanding of HK-31 on 3/14/57 

Three BZ samStates “No dunormally worn personnel.” 

TDCC 000051 4/3/57 

C. Moser (Dow Madison) 

Meeting report: Dow with Mallinckrodt 

Planning for upcoming U extrusion run and sampling by Mallinckrodt 

This indicates extrusion at Ddid not begin April 1957. 

TDCC 000055 4/10/57 Handwritten note 

that badges were sent for processing 

Bay City list of job titles (names redacted) and badge nos. 

Indicates that being used somthis refers to B

TDCC 000057 4/12/57 

D. Levy (Dow Madison) 

Memo to G. Ansel (Dow Madison) 

Correction to 3/8/57 memo (TDCC 000045) 

Corrected hanexposure units 000045 

TDCC 000058 6/19/57 

L. Silverstein (Dow Madison) 

Paper: Industrial Health Experience with Mg-Th Alloys 

Exterior rad rates for Th pellets and ThF4, hardener, Mg-Th alloy metal, and sludges. Workplace and BZ air samples during 35,000# HM-21 alloying campaign on 7/22-23/56. Workplace and BZ air samples during grinding, filing, buffing, sawing, drumming, chemical milling, welding, melting, and 3 fires of HK31A) 

5 BZ and 9 arduring HM-21 processing; 8 samples durinmechanical opsamples durinIncidents: At occurred durinprocessing; 3 were started in sample emissiLists Mg-Th a31A, HM-21X
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

(HM-21 data same as in TDCC 000005) 

ZH-62A, and 

TDCC 000083 Duplicate copy of 

TDCC 000058 

--- --- --- 

TDCC 000103 7/28/57 

D. Levy (Dow) 

Semi-annual IH Summary 

Includes area air sampling for Th from 9/55 to 3/57 for pot room, slab oven, mill, wire brush machine, slab scalper, hand sanding 

Th air concenvarious operatthese data precovered periosame type ope

TDCC 000108 7/31/57 

L. Silverstein (Dow) 

Memo to W. Saunders (Dow) 

Personnel protection for fighting Mg-Th alloy fires 

No 

TDCC 000109 10/17-18/57 

L. Silverstein (Dow) 

Paper: Is Radiation Safety a Consideration in Working Mg-Th Alloys? 

An addition to TDCC 000058, with basically the same data (a few discrepancies regarding which samples are BZ or area samples) 

No 

TDCC 000149 10/17-18/57 

L. Silverstein (Dow) 

“ (Part 2) Introduction says it is “Part 2” 

but it is a repeat of the same information. 

No 

TDCC 000155 11/27/57 

F. Mansfield (Dow) 

Memo to L. Silverstein (Dow) 

Protesting requirement for Radioactive Material labels for Th alloys; requested Silverstein to come talk with folks at Madison 

No 

TDCC 000157 11/26/57 

L. Silverstein (Dow) 

Memo to D. Levy (Dow) 

Dow Madison now agreeable to labeling 

No 
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

TDCC 000158 12/20/57 

H. Hoyle (Dow) 

Memo to L. Treat (Dow) 

Answers to questions about Th processing hazards 

No 

TDCC 000162 12/23/57 

D. Levy (Dow) 

Memo to F. Mansfield (Dow) 

Assurance that HK-31 alloy processing will not result in exposures in excess of limits 

No 

TDCC 000164 12/30/57 

L. Silverstein (Dow) 

Letter to C. Mitchell (Dow) 

Alpha counts for air samples taken 12/2/57; will be submitted for spec analysis to determine Th (see TDCC 000166) 

BZ sample da000166) 

TDCC 000166 12/2/57 

C. Mitchell (Dow) 

Letter to L. Silverstein (Dow) 

Request to analyze 2 BZ samples from sanding HK-31 alloy on 12/2/57 

BZ samples d

TDCC 000167 J. Peloubet (Dow) Mg-Th Alloys - 

Industrial Health Experience in Fabrication and Production 

Compilation of previous reports by L. Silverstein (TDCC 000031 & TDCC 000058) plus densitometer readings of exposed X-ray film 

See TDCC 00000058 Densitometer exposed X-ray 

TDCC 000191 4/16/58 

L. Silverstein (Dow) 

Letter to C. Mitchell 

Spec analysis results for 3 BZ air samples from HK-31 alloy sanding on 3/24/58 

BZ samples dsanding 

TDCC 000194 6/27/58 

D. Levy (Dow) 

Memo to G. Ansel (Dow) Annual Industrial Hygiene Summary 

(no summary attached) See TDCC 00

TDCC 000198 

TDCC 000195 10/15/58 

B. Milner 

Lab results Spectrophotometric 

measurement of particulates on 

Spectrophotom(Would need c
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

air filter samples (8/29-30/58) for slab unit and billet unit 

factor to Th coactivity) 

TDCC 000198 5/21/59 

D. Levy (Dow) 

Memo to J. Burns (Dow) Annual Industrial Hygiene Summary 

Includes area air sampling for Th from 9/55 – 3/59 for pot room, slab oven mill wire brush machine, slab scalper, hand sanding 

Th air concenvarious operatthese data precovered periosame type opeRepeats data f000103 

TDCC 000207 3/19/59 

D. Levy 

Memo to “Harold” Request for Th analysis of 

sample of oxides from surface of HK-31 coils; asks if respirators should be used by personnel handling coils 

No 

TDCC 000209 3/26/59 Note to D. Levy (Partially illegible) “respirators 

are not necessary unless the man is exposed to an obviously dusty atmosphere” (no Th results) 

No 

TDCC 000210 (duplicate of 000418) 

8/28/59 J. Peloubet (Dow) 

Letter to L. Rogers (AEC) 

See TDCC 000418 Data attachme

from TDCC 0included in TD(some of data 000031 and T

TDCC 000212 12/15-16/59 Industrial Hygiene 

Sample Record 

Area air sample results for Pot room and Sludge Recovery 

Area air sampPot room and Recovery 

TDCC 000224 12/15/59 Air Sample Sample # 3 from above See TDCC 00
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

Radioactivity Counting Record 

TDCC 000228 12/16/59 Air Sample 

Radioactivity Counting Record 

Samples # 4, 5, & 6 from above 

See TDCC 00

TDCC 000233 8/4/60 

W. Saunders (Dow) 

Letter to E. McFall (AEC) 

Response to questions from 8/3/60 visit; rad survey data from Mg-Th sludge dump and virgin Th storage cage 

Additional surthe sludge dumlocations - opeand from the T(2 locations - These surveys reported in TD(which was cibut these data included. 

TDCC 000236 4/15/57 

(Agreement) 

Memos, letter, and copy of agreement between Mallinckrodt and Dow 

Agreement outlines scope of experimental extrusion work on uranium 

No 

TDCC 000250 1/23/58 – 11/4/65 Purchase Orders Most are for Dow Madison to 

supply Mg alloy welding wire and rods, ignitor leads, heating coil wire, sheets, etc. to Weldon Spring; other products, Dow supplier sites, and Mallinckrodt sites are also included. 

Some P.O.s arcontaining allcommercially product (eg., T

TDCC 000290 7/2/57 – 1/16/61 Purchase Orders See above comment See above com
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information fTDCC 000316TDCC 000304 campaigns for straightening. completed 12/campaign #2 c1/25/60 

TDCC 000330 1/12/51 Quit Claim Deed Government conveys to Dow 

the Madison property for $1.5 million 

No 

TDCC 000346 5/11/88 

C. Young (DOE?) 

Record of Contact with J. Carlson who had worked at Dow Madison 

Carlson’s statements about U extrusion operation; protective clothing was provided by Mallinckrodt 

No 

TDCC 000349 11/30/56 

R. Young (Dow) 

Letter to L. Johnson (AEC) 

Request to purchase 20# of high purity Th metal under Dow AEC license 

Commercial T

TDCC 000350 12/6/56 Dow application 

for AEC license 

Covers 135,000# Th metal & 30,000# Th fluoride or oxide per year to be used to make Mg alloys for structural use. Sites covered include Midland, MI; Bay City, MI; Madison, IL; and Freeport, TX. 

Commercial T135,000# Th m30,000# Th fluper year (for 4 

TDCC 000354 12/19/56 

L. Johnson (AEC) 

Letters to Dow Granting of AEC license to 

receive/possess unlimited quantities of Th metal &/or compounds; permission to 

Commercial T
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

procure 20# of Th (see TDCC 000210) 

TDCC 000357 1/21/57 

O. Heath (Dow) 

Letter to L. Johnson (AEC) 

Submittal of Form AEC-8 covering unlimited purchase of sintered Th pellets 

Commercial T

TDCC 000361 2/1/57 

L. Johnson (AEC) 

Letter to Dow Authorization to receive 

sintered Th pellets 

Commercial T

TDCC 000362 6/26/57 

L. Silverstein (Dow Midland) 

Letter to H. Price (AEC) 

Request for exemption from posting and labeling requirements of 10CFR20 for areas and containers in which Mg alloys containing up to 4% Th are stored and fabricated; includes film badge data from HK-31 casting jobs 

Personnel film 13 day period (20 specific jolist is from Bathe same as th000055) 

TDCC 000385 7/12/57 

J. Delaney (AEC) 

R. Borlik (AEC) List of items pending, 

including Dow’s request for exemption from posting and labeling requirements of 10CFR20; extensive discussion of potential impacts of exemption, and recommendation for exemption 

No 

TDCC 000393 8/8/57 Notice to file Notice of addition of 

documents to docket in public document room files 

No 

TDCC 000395 11/20/57 

O. Heath (Dow) 

Letter to L. Johnson (AEC) 

Submittal of Form AEC-2 application for renewal of 

Commercial T135,000# Th m
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

license covering 135,000# Th metal & 30,000# Th fluoride or oxide per year to be used to make Mg alloys for structural use. Sites covered include Midland, MI; Bay City, MI; Madison, IL; and Freeport, TX. 

30,000# Th fluper year (for 4 

TDCC 000404 1/1/58 

J. Delaney (AEC) 

Letter to Dow Granting of AEC license to 

receive/possess unlimited quantities of Th metal &/or compounds 

No 

TDCC 000405 9/23/58 

R. Barker (AEC) 

File memo of phone call from J. Peloubet (Dow) 

Request for extension of the exemption for fabricated MgTh alloy parts to cover also pieces of metal provided along with the fabricated part as repair material. 

No 

TDCC 000406 7/14/58 

H. Price (AEC) 

Memo to file Determination that Dow 

license may be amended to allow exemption from posting and labeling 

No 

TDCC 000407 7/14/58 

H. Price (AEC) 

AEC license Granting amendment of license 

exemption from posting and labeling requirements 

No 

TDCC 000408 7/14/58 

H. Price (AEC) 

Letter to Dow Cover letter transmitting 

amended license 

No 

TDCC 000409 8/29/58 

J. Peloubet (Dow) 

Letter to L. Johnson (AEC) 

Request for exemption of component parts and finished 

No 
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

products which contain Mgbased alloys with nominal 1% Th 

TDCC 000411 9/23/58 

R. Barker (AEC) 

File memo of phone call from J. Peloubet (Dow) 

Request for extension of the exemption for fabricated MgTh alloy parts to cover also pieces of metal provided along with the fabricated part as repair material. 

Same as TDC

TDCC 000412 12/5/58 

O. Heath (Dow) 

Letter to H. Price (AEC) 

Submittal of Form AEC-2 application for renewal of license covering 135,000# Th metal & 30,000# Th fluoride or oxide per year to be used to make Mg alloys for structural use. Sites covered include Midland, MI; Bay City, MI; Madison, IL; and Freeport, TX. 

Commercial T135,000# Th m30,000# Th fluper year (for 4 

TDCC 000417 1/1/59 

J. Delaney (AEC) 

Letter to Dow Granting of AEC license to 

receive/possess unlimited quantities of Th metal &/or compounds 

No 

TDCC 000418 8/28/59 

J. Peloubet (Dow) 

Letter to L. Rogers (AEC) 

Presents argument and data to justify not using local exhaust ventilation for welding Mg-Th alloys. Provides Th air sample data for welding Mg-Th metal 

Th air sample welding Mg-T(some of data 000031 and T

TDCC 000421 11/30/59 Letter to H. Price Submittal of Form AEC-2 Commercial T
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

O. Heath (Dow) (AEC) application for renewal of 

license covering 135,000# Th metal & 2,000# Th fluoride or oxide per year to be used to make Mg alloys for structural use. Sites covered include Midland, MI; Bay City, MI; and Madison, IL. 

135,000# Th mTh fluoride or (for 4 sites) 

TDCC 000426 1/1/60 

J. Delaney (AEC) 

Letter to W. Heath (Dow) 

Granting of AEC license to receive/possess Th metal &/or compounds (quantity not specified) 

No 

TDCC 000427 1/1/60 

J. Delaney (AEC) 

Letter to W. Heath (Dow) 

Amendment to license adding Sequoia Metalcraft Co., San Carlos, CA 

No 

TDCC 000428 11/30/60 

R. Hageman (AEC) 

Letter to H. Price (AEC) - Inspection Report 

No noncompliances, but questioned whether burning Mg-Th scrap in the disposal area was covered under the incineration provisions of the Dow license. Includes rad survey data for the sludge dump and Th storage cage. 

No 

TDCC 000438 1/1/61 

J. Delaney (AEC) 

Letter to W. Heath (Dow) 

Granting of AEC license to receive/possess unlimited quantities of Th metal &/or compounds 

No 

TDCC 000439 1/20/69 Dow product info 

sheet 

Mg forging billet and ingot pricing and shipping info 

No 
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

(includes HM-21A which contains Th) 

TDCC 000443 1/2/69 Mg Tolling 

Agreement, Exhibit D 

Table 1 shows chemical composition of Mg alloys – only 3 contain Th (HK31A, HM21A, and HM31A) 

List of Th-conSame as TDC

TDCC 000478 No date Digest of 

Specifications for Mg Products 

Lists various specifications (Military, ASTM, Federal, AMS) for Mg extrusions, sheets, plates, etc. 

No 

TDCC 000498 7/1/68 Digest of 

Specifications and Standards for Al Mill Products 

Specs for Aluminum products No 

TDCC 000529 Dow ????(illegible) 

Exhibit B 

List of plant equipment No 

TDCC 000534 1/2/69 List of Product 

Standards 

Table 1 shows chemical composition of Mg alloys – only 3 contain Th (HK31A, HM21A, and HM31A) 

List of Th-conSame as TDC

TDCC 000541 12/1/62 Key to General 

Layout of Entire Plant 

ID numbers for rolling mill, extrusion, heavy press, alloy, and general plant equipment 

No 

TDCC 000554 (duplicate of 000534) 

----- ----- ----- ----- 

TDCC 000589 5/31/57 Dow 1957 Annual 

Report 

“Among promising new products are our new thoriumNo 
SEC Petition Evaluation Report for Petition SEC-00079 

Document file # (Beginning Page)

Date/Author/Site Document Type Content New or Differ

Information f

containing alloys ....They are being used principally in missiles and high speed aircraft ...” 

TDCC 000617 5/31/58 Dow 1958 Annual 

Report 

“Our new high-temperature thorium alloys are finding many applications in missiles and rockets.” 

No 

TDCC 000645 5/31/59 Dow 1959 Annual 

Report 

“Military use still accounts for a large share of sales and the continued growth of the missile program has increased the demand for castings and mill products of the new thorium alloys...” 

No 
SEC Petition Evaluation Report Petition SEC-00079 

TABLE 2 - RADIATION MEASURES/SAMPLES OF THORIUM ACTIVITIES IN NEW DOW DOCUM(Much of the data available for the Dow Madison site are used repeatedly in various reports, papers, and presenta

summarized or presented in different combinations, formats, and units. In order to clarify what data are availabledouble-counting data, this table presents the original measurement/sampling date, type and number of measures/various documents in which the data are utilized. Note: Some data pre-date the covered period, but should geneconditions during the covered period. Also, some data are for the Bay City, MI site, but Mg-Th alloy operations 

the two sites, as indicated by a list of job titles from that site.) Date1 Area/Activity Type Number of Samples/ 

Measurements 

Measur

Personnel Monitoring4/10/57 HK-31 pour off, 

knockout, sandblast, sawing, chipping, trim, pickling, filing, buffing, heat treat, etc. 

Personnel film badges 27 (20 specific jobs) (Note: these 

are for Bay City – Madison would have had similar jobs) 

<10 – 75 

Air Samples (BZ) 7/22 - 23/562 35,000# HM-21 

alloying campaign 

BZ air samples 5 Th, Ra22

short-liv

3/14/57 Hand sanding HK-31 BZ air samples 3 Th 12/2/57 Hand sanding HK-31 BZ air samples 2 Th 3/24/58 Hand sanding HK-31 BZ air samples 3 Th No date Grinding, filing, 

buffing, sawing, drumming 

BZ air samples 8 Th 
SEC Petition Evaluation Report Petition SEC-00079 

Date1 Area/Activity Type Number of Samples/ 

Measurements 

Measur

Air Samples (BZ) (Continued) No date (first reported in 12/56) 2

Welding alloy (TDCC 000058 and TDCC 000418 were cited in PER but welding data were not used) 

BZ air samples 22 (not all results reported in some 

documents) TDCC 000058 indicates this was HK-31 welding, but the Th % of several welds indicate that they would be HM-21 per specification 

Th 

No date Acid pickling HK-31A BZ air samples “a very few” Th No date HK-31A Fires BZ air samples 1 Th Air Samples (Work Area) 9/55 – 3/57 Pot room, slab oven, 

mill, wire brush, slab scalper, hand sanding 

Work area air samples 

>13 (these are semi-annual summaries – data may be included in other documents) 

Th 

2/14/562 ThF4 storage (Bldg. 

376) 

Work area air samples 

2 (=2 locations x 1 sample) Th, Ra22

short-liv

4/11 - 12/562 Mg-Th Hardener 

Production (Bldg. 152) 

Work area air samples 

4 (=4 locations x 1 sample) Th, Ra22

short-liv

4/10 – 5/8/562

Hardener melting (Bldg. 152) 

Work area air samples 

7 (=7 locations x 1 sample) Th, Ra22

short-liv

5/2/562 Chemical Milling HK31 Work area air samples 2 (6” above surface & 5’ from tank) 

This sampling in Bay City 

Th, Ra22short-liv

5/8/562 Mg/Th fire (Bldg. 152) Work area air 

samples 

2 (=2 locations x 1 sample) Th, Ra22

short-liv

7/22 - 23/562 35,000# HM-21 

alloying campaign 

Work area air samples 

9 (Note: some discrepancy in original reports regarding if these are BZ) 

Th, Ra22short-liv
SEC Petition Evaluation Report Petition SEC-00079 

Date1 Area/Activity Type Number of Samples/ 

Measurements 

Measur

Air Samples (Work Area) (Continued) 9/17 - 18/562 HM-21 & HK-31 

alloying & casting 

Work area air samples 

15 

α and 

β 

8/29 – 30/58 Slab and billet units Work area - Air 

particulates - Automatic filter paper sampler (“Smoke sampler”) 

13 from slab unit 25 from billet unit 

% transmission/ units 

12/15 - 16/59 Pot room and Sludge 

recovery HK-31 

Work area air samples 

13 Th 

No date Chemical Milling HK31 Work area air samples 2 (4” above surface & 5’ from tank) Th (

α an

No date HK-31A Fires Work area air 

samples 

5 Th 

No date Rolling mill/ovens area Work area air 

samples 

2 Th 

No date Welding alloy 

TDCC 000058 and TDCC 000418 were cited in PER but welding data were not used 

Work area air samples 

1 Th 

No date Melting HK-31 at 

various ages since last melting 

Work area air samples 

8 Th 
SEC Petition Evaluation Report Petition SEC-00079 

Date1 Area/Activity Type Number of Samples/ 

Measurements 

Measur

External/Surface Radiation Surveys 1/10/562 Storage/Handling HK31A alloy (max. 3.5% 

Th) Stacked Sheet, crated sheet, and slabs 

Readings at surface and at distance intervals on HK31 sheets before and after coating and packaging. Surface radiation and 1 foot increments up to 7 feet of HK31 slabs stacked 9’ tall. Also readings on HK11 and HM21. 

About 60 readings total (not all results reported in some documents - only 13 reported in TDCC 000058) 

β and 

γ 

7/22-23/562 Th pellets and HM21 

scrap 

External rad on contact and working distance 

At least 4 mr/hr 

2/27/57 Alloying of Th pellets 

and hardener 

External rad survey (Unstated) 

β and 

γ 

No date Handling Th pellets, 

ThF4 powder, hardener 

Surface radiation (Unstated) mr/hr 

No date Storage/Handling of 

non- and heat-treated HK-31 

Direct counts; Swipes 

4 7 

α and 

β 

No date Alloys with Th content 

from 0.0 to 10.0 % 

Photographic film exposure for 24, 144, 216 hrs. 

8 Densitom

reading 

No date Sludges Surface radiation Maximum/average after 1 month Mr/hr 
SEC Petition Evaluation Report Petition SEC-00079 

Date1 Area/Activity Type Number of Samples/ 

Measurements 

Measur

External/Surface Radiation Surveys (Continued) 8/4/60 (date of inspection) 

Mg-Th sludge dump; Virgin Th storage cage 

External rad survey 11 locations (open & closed)(4 in 

TDCC 000428) 5 locations (open & closed)(3 in TDCC 000428) These reports cover the same surveys, but TDCC 000428 reported only part of the data. (Distance of reading above 7000# of master alloy scrap reported as 12’ in TDCC 000233, but as 12 inches in TDCC 000428) 

β and 

γ 

1 Date = actual date of measurement/sampling or date of earliest document reporting the data 2 = predates covered period