February 1, 2018 

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

Obs. No. 

(Doc. 

Obs. No.)

Observation Resolution Status

1 

(Gen. 

No. 1)

Lack of Coverage of Offsite Activities

Apparently, some work was performed by offsite contractors for the 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 TBDs.

Exposures occurring 

off site are not covered; 

therefore, this 

observation has been 

resolved.

Considered 

resolved by WS 

WG 2/1/2018.

2 

(TBD-3 

No. 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.

Considered 

resolved by WS 

WG 2/1/2018.

3 

(TBD-4 

No. 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.

Considered 

resolved by WS 

WG 2/1/2018.
Weldon Spring Site Profile Observations Matrix 2 SC&A – February 1, 2018

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.

Obs. No. 

(Doc. 

Obs. No.)

Observation Resolution Status

4 

(TBD-4 

No. 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 consists 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.

Considered 

resolved by WS 

WG 2/1/2018.

5

(TBD-4 

No. 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.

Considered 

resolved by WS 

WG 2/1/2018.

6 

(TBD-5 

No. 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.

Considered 

resolved by WS 

WG 2/1/2018
Weldon Spring Site Profile Observations Matrix 3 SC&A – February 1, 2018

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.

Obs. No. 

(Doc.

Obs. No.)

Observation Resolution Status

7

(TBD-5 

No. 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/m3 compared to 100 dpm/m3 for 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), b), and c) 

considered 

resolved by WS 

WG 2/1/2018.

8 

TBD-6 

(No. 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) and b) 

considered 

resolved by WS 

WG 2/1/2018.
Weldon Spring Site Profile Observations Matrix 4 SC&A – February 1, 2018

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.

Obs. No.

(Doc. 

Obs. No.)

Observation Resolution Status

9 

(TBD-6 

No. 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) and b) 

considered 

resolved by WS 

WG 2/1/2018.

EU = enriched uranium; LOD = limit of detection; MAC = maximum allowable concentration; RU = recycled uranium; TBD = technical basis document; WG = Work Group; WS = Weldon 

Spring