November 2017

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 document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

WELDON SPRING PLANT SITE PROFILE OBSERVATIONS MATRIX

Doc., 

Obser.

No.

Observation Resolution Status

Gen., 1 Lack of Coverage of Offsite Activities 

Apparently, some work was performed by offsite contractors for the Weldon Spring (WS)

site, which consisted of inspection of uranium metal samples by cutting of the material and 

then irradiation using high-energy betatrons. This procedure could induce fission in uranium 

and create fission products that could emit radiation not normally encountered in a uranium 

facility, and expose nearby WS workers and transporters who may not have normally been 

badged; and it could have created inhalable radioactive material for which bioassays were 

not performed. This subject should be investigated and addressed in the appropriate 

technical basis documents (TBDs). 

Exposures occurring 

off site are not 

covered; therefore, 

this observation has 

been resolved.

Resolved

TBD-3, 

1

Equation 3-1 

The equation Dom = SnDi, is provided on page 6 of TBD-3 (ORAUT 2005c) and the 

individual terms in the equation are defined, except for the term “S.” This may have been 

meant to be the Greek symbol sigma “Σ” for summing, instead of an “S.”

NIOSH removed 

Equation 3-1 from 

Rev. 01, 1/30/2013.

Resolved
Weldon Spring Site Profile Observations Matrix 2 SC&A – November 2017

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Doc., 

Obser.

No.

Observation Resolution Status

TBD-4, 

1

Application of Environmental Doses 

Section 4.1.2 of TBD-4 (ORAUT 2005d, page 6) states the following: 

The term occupational environmental dose refers to the radiation dose 

received in the course of work duties outside plant buildings, but on the 

WSCP site. This TBD considers internal and external exposures to 

radionuclides in the outdoor environment separately in calculating this dose. 

Dose reconstructors can use estimated occupational environmental dose to 

develop a reliable individual dose when a worker was not monitored 

adequately. 

However, this statement should be qualified to apply only to workers that were not 

routinely exposed and would not be considered a radiation worker by today’s standards. If 

the worker would be considered a radiation worker by today’s standard, then the dose 

reconstruction should be based on coworker dose data, not environmental dose data.

TBD-4, Rev. 01 of 

5/17/2013, 

Section 4.1.1, page 8, 

provides correct 

wording.

Resolved

TBD-4, 

2

Special Uranium Curie 

The equation for the special uranium curie is correct on page 31 of TBD-5 (ORAUT 

2005e), and on page 14 of TBD-4 (ORAUT 2005d), where it is stated that “The original 

data are reported in dps from units of special uranium microcuries, defined as the sum of 3.7 

× 104 dps from 238U, 3.7 × 104 dps from 234U, and 9 × 102 dps from 235U.” However, it goes 

on to state, “Converting to units of Bq, the special uranium μCi is multiplied by 3.7 ×104

Bq/μCi and by a factor of 2.024 to report total uranium activity” (emphasis added). The 

factor of 3.7 × 104 Bq/μCi is correct, but the factor of 2.024 should be omitted, because the 

special uranium μCi already includes the 2.024 factor [which consist of the sum of (3.7 × 

104 dps from 238U, 3.7 × 104 dps from 234U, and 9 × 102 235U)/(3.7 × 104 dps from 238U) = 

2.024].

SC&A has analyzed 

this issue, and the 

associated wording, 

and agrees with 

NIOSH and finds the 

observation resolved.

Resolved
Weldon Spring Site Profile Observations Matrix 3 SC&A – November 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

Doc., 

Obser.

No.

Observation Resolution Status

TBD-4, 

3

Corrections to Text of TBD-4 

 The equation on page 5 should read, “WL Working Level = 1.3 × 105 MeV of alpha 

energy in 1 liter of air;” not “105 MeV.”

 The equation on page 5 should read, “WLM Working Level Month = Exposure from 

1 WL of radon daughters for 170 working hours;” not “...or radon...”

TBD-4, Rev. 01 of 

5/17/2013, corrected 

this wording.

Resolved

TBD-5, 

1

Years of Thorium Use 

Table 5-2 (ORAUT 2005e, page 10) lists the starting date for potential Th-232 exposure as 

1963, 1965, and 1966 depending on the building. This should be verified, as it would seem 

that WS would have processed thorium fairly uniformly throughout the different buildings, 

at least on a yearly basis. 

Thorium exposures

have been addressed 

in the site profile 

findings.

Resolved

TBD-5, 

2

Changes in Text of TBD-5 

a) The second paragraph on page 12 appears to be out of place in this location; it may be 

more applicable to the contents of page 9. 

b) The last paragraph on page 12 contains an incorrect table and document reference; it 

should read, “Table 2-7 in ORAU (2005b) gives the annual (fiscal year) mass receipts 

of each of these feed materials;” not “Table 2-4 in ORAU (2005a)...” 

c) The second paragraph on page 36 states that “Under these assumptions, the claimantfavorable assumption results in an annual exposure of 735 MAC-hr (in comparison to 

1,050 MAC-hr for Fernald)...” when actually it is 1,050 MAC-hr for the WS site, 

based on the definition of the MAC for the WS facility. Considering that the MAC for 

the WS facility was set at 70 dpm/m3compared to 100 dpm/m3for the Fernald facility, 

it would be equivalent to 735 MAC-hr as defined for the Fernald facility. 

a) Does not affect 

dose 

reconstruction.

b) Correct text on 

page 13 of Rev.

02, 5/21/2013 of 

TBD-5.

c) TBD-5, Rev. 02 of 

5/21/2013, Section 

5.6.1.2, page 40, 

uses a different 

methodology. This 

observation is no 

longer applicable.

a) Resolved

b) Resolved

c) Resolved
Weldon Spring Site Profile Observations Matrix 4 SC&A – November 2017

NOTICE: This document has been reviewed to identify and redact any information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

Doc., 

Obser.

No.

Observation Resolution Status

TBD-6, 

1

Changes in Text of TBD-6 

a) Table 6-6, page 15, contains “?” where the gamma symbol should be, which causes 

some confusion while reading the contents of the table. 

b) In Table 6-6, page 15, under the Report column, the text in the first and second row 

both refer to “Figures A-1 – A-6”; however, they describe different contents. 

Apparently, each one of them should refer to only a few of the Figures, not all six of 

them. 

a) TBD-6, Rev. 01 

of 2/6/2013, Table 

6-5, page 16, 

provides correct 

wording. 

b) Issue does not 

affect dose 

reconstruction. 

a) Resolved

b) Resolved

TBD-6, 

2

Missing Data in TBD-6 

a) Table 6-2 (Summary of historical recorded dose practices) on page 12 is not complete, 

in that it does not contain any information (has blank spaces) for the time periods other 

than 1958–1966. No Dosimeter measured quantities or Compliance dose quantities are 

provided for 1957, or the periods when EU and RU (Plant operations period Special 

case for enriched uranium) were processed, or 1967–1984 (Maintenance period), or 

for Landauer. This information is important during dose reconstruction to correctly 

interpret the recorded data and to determine if adequate data exist to assign accurate 

doses, especially for beta doses, which were prevalent at the WS site. 

b) For the period 1957–1969, Table 6-14 (page 25) provides data for potentially missed 

gamma dose during 1957–1958 and 1959–1969; however, Table 6-16 only provides 

beta missed dose data for 1957–1966 (does not include 1967, 1968, and 1969). 

a) Issue does not 

affect dose 

reconstruction.

b) The missed dose 

for a given year 

can be determined 

by using the LOD 

of 50 mR gamma 

and 80 mrep beta 

as provided on 

page 24 and the 

appropriate 

exchange 

frequency. The 

tables are for 

convenience and 

do not affect dose 

reconstruction.

a) Resolved

b) Resolved