Updated TBD-6000 Issues Matrix 1 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ISSUE RESOLUTION MATRIX FOR SC&A FINDINGS ON TBD-6000 

NIOSH Responses Added on March 6, 2009 

SC&A Response to NIOSH Response Added March 9, 2009 

Additional Material Added Following the October 14, 2009, Work Group Meeting 

Additional Material Added Prior to October 12, 2010, Work Group Meeting 

Issue 1: Failure to Discuss Elevated Levels of Th-234 and Pa-234m Close to Surface of Freshly Cast 

SC&A Finding: The TBD would benefit from a discussion of the possibility and potential dosimetric significance 

of uranium metal-working operations involving freshly cast uranium ingots, where there might be elevated levels of 

Th-234 and Pa-234m close to the surface of the ingot. Furthermore, it is not clear from the TBD whether scrap 

recovery at any of the covered AWE sites involved melting and casting of uranium. This should be investigated, 

since it could make a significant difference in the external dose reconstruction protocol. 

NIOSH Response: It is agreed that the TBD would benefit from a discussion of uranium progeny concentrations 

during uranium casting. The issue requires additional research. Also, scrap recovery involves several steps one of 

which may be remelting the uranium for casting. At facilities that normally cast uranium, this was a viable step to 

recovering some of the scrap. However, a facility that did not have the recasting equipment would not utilize this 

step solely to recover uranium. Since most facilities that cast uranium would also have some scrap recovery efforts, 

both types of work would normally be considered. 

SC&A Reply: It appears that NIOSH and SC&A are in agreement on this issue. The work group may want to close

the issues or leave it in abeyance until TBD-6000 is revised to accommodate this issue. NIOSH may wish to refer to 

Putzier 1982 for a discussion of uranium progeny concentrations on the surface of freshly cast (< 100 d) uranium 

ingots (see list of references). 

October 14, 2009, Work Group Meeting: This issue was briefly discussed at the work group meeting and NIOSH 

agreed to look into how they will address this matter. SC&A recommended that this issue remain in abeyance until 

the TBD is revised. 

December 16, 2009, Work Group Meeting: NIOSH reviewed the just-published Issue 1 White Paper, 

Consideration of Recasting Increasing Progeny Concentration (Allen 2009) (See Attachment 6). There was general 

agreement between SC&A and NIOSH that the 95th percentile values of beta dose determined using TBD-6000 were 

conservative and claimant favorable. However, it was not clear whether using the 95th percentile in a deterministic 

calculation was more or less claimant favorable than using the full lognormal distribution based on a geometric 

mean and geometric standard deviation. SC&A was requested by the Work Group to include some hypothetical 

probability of causation (POC) calculations in the paper it was preparing in response to Allen 2009. 

Actions Subsequent to December 16, 2009, Work Group Meeting: SC&A delivered a memorandum on 

December 28, 2009, documenting its comments on Allen 2009 and providing results of some hypothetical POC case 

studies (SC&A 2009) (See Attachment 7). In one hypothetical case comparing the POC for skin cancer (other than 

hands and arms), both the full distribution and the deterministic 95th percentile from TBD-6000 resulted in high 

POCs (82.6% for full distribution and 89.1% for 95th percentile). This comparison is only applicable to skin cancer 

associated with beta dose. Results were significantly different for photon dose to the lungs. 

May 12, 2010, Work Group Meeting: There was extensive discussion on Issue 1, particularly with regard to how 

the Putzier effect would be addressed in the revision of TBD-6000. Member Griffon was concerned that dose to the 

hands might not be adequately covered by the existing TBD-6000 approach when the Putzier effect existed. 

Chairman Ziemer asked if NIOSH could prepare suggested language for a revised TBD-6000 addressing the Putzier 

effect. NIOSH agreed to do so. 

Developments Since May 12, 2010: NIOSH provided a White Paper documenting proposed language to be used in 

TBD-6000 on the Putzier effect (Allen 2010), which is included here as Attachment 8. 

Board Action: 
Updated TBD-6000 Issues Matrix 2 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Issue 2: Omission of External Exposure to Skin from Beta Particles Emitted from Contaminated Surfaces 

SC&A Finding: The TBD presents generic photon exposure conversion factors for submersion in an airborne 

plume of uranium (expressed in units of mR/hr per dpm [α]/m3

) and for standing on a contaminated surface 

(expressed in units of mR/hr per dpm [α]/m2

). However, the TBD does not present similar dose conversion factors 

addressing external exposure to skin from beta particles emitted from contaminated surfaces. SC&A’s calculations 

of the potential skin exposures from this pathway reveal that this source of exposure is significant relative to photon 

exposures and should be addressed in the TBD. 

NIOSH Response: It is agreed the beta dose should be addressed if the photon is to be addressed. It is however, 

important to realize the external dose from contaminated surfaces is small compared to that from metal. The dose 

rates in Table 6-4 indicate that, in the worst case, the photon dose from this source of exposure is less than 1% of 

that from the metal itself. 

SC&A Reply: We agree with the NIOSH observation regarding the relative magnitude of the exposures from 

contaminated surfaces and metal ingots. However, since TBD-6000 has generic applicability, there may well be 

cases where a worker had been exposed to contaminated surfaces but not to metal ingots. In such cases, doses to 

skin and superficial organs would be underestimated. It appears that NIOSH and SC&A are in agreement on this 

issue. The work group may want to close the issues or leave it in abeyance until TBD-6000 is revised to 

accommodate this issue. 

October 14, 2009, Work Group Meeting: This issue was discussed at the October 14, 2009, work group meeting, 

and NIOSH agreed to include a table in TBD-6000 addressing external exposures to beta associated with 

contaminated surfaces. SC&A recommends that this issue be held in abeyance until the TBD is revised.

May 12, 2010, Work Group Meeting: Chairman reaffirmed that Issue 2 remains in abeyance pending revision of 

TBD-6000. 

Board Action: 

Issue 3: Questions Regarding Recycled Uranium 

SC&A Finding: Based on this review, we conclude that the default concentrations of Pu-239, Np-237, and Tc-99 

contained in recycled uranium shipped to AWE facilities for metal working, as presented in TBD-6000, are 

scientifically valid and claimant favorable. However, we do not understand the reason for including Th-232 and 

Th-228 in Table 3.2 of TBD-6000. Furthermore, a default assumption that RU was present during and after 1953 is 

appropriate unless there is specific evidence from an AWE site’s own records that only virgin uranium was handled 

there. 

NIOSH Response: The origin of the thorium values is being explored, however, since the values provided represent 

an activity less than 6 millionths that of the uranium, we consider it a minor issue. Also, the default assumption 

mentioned in the comment is indeed the default specified in the TBD in the second bullet in section 7.1.3. 

SC&A Reply: It appears that NIOSH and SC&A are in agreement on this issue. The work group may want to close 

the issues or leave it in abeyance until TBD-6000 is revised to accommodate this issue. 

October 14, 2009, Work Group Meeting: This issue was discussed at the October 24, 2009, work group meeting. 

Dr. Poston stated that Th-232 is sometimes associated with RU and therefore it is appropriately included in TBD6000 as a trace contaminant in RU. SC&A recommends that this issue be designated as closed.

May 12, 2010, Work Group Meeting: Chairman reaffirmed that Issue 3 is closed. 

Board Action: 
Updated TBD-6000 Issues Matrix 3 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Issue 4: Airborne Uranium Dust Concentrations Recommended in the TBD Might Not Be Claimant Favorable 

SC&A Finding: Default airborne dust loadings used in the TBD to derive external exposures and inhalation exposures are 

based on data provided in Harris and Kingsley (1959). The TBD would benefit from including a review of the time-weighted 

daily average uranium dust loadings reported in the Adley et al. report, Study of Atmospheric Contamination in the Metal 

Melt Building (AEC 1952), and in the site profile for Simonds Saw and Steel, ORAUT-TKBS-0032 (ORAUT 2005). 

SC&A’s review of these documents revealed that the bounding, default, time-weighted average airborne uranium dust 

concentrations recommended in the TBD might not be claimant favorable. 

NIOSH Response: This comment is not clear. The SC&A report indicates that some of the highest numbers in Adley are 

higher than the geometric mean in the TBD. The highest values should more appropriately be compared to the 95th percentile 

of the distribution in the TBD. 

SC&A Reply: As indicated on page 17 of SC&A’s review of TBD-6000, time weighted average airborne concentrations of 

uranium in the breathing zone of workers at the Hanford Metal Melt Facility, as cited by Adley et al. (AEC 1952) appear to 

be about twice the values adopted as default values in TBD-6000. We believe that NIOSH should revise TBD-6000 to 

explicitly consider the extensive data described in AEC 1952. SC&A recommends that this issue remain open. 

October 14, 2009, Work Group Meeting: This issue was discussed at the October 14, 2009, work group meeting. Prior to 

the meeting, NIOSH distributed a white paper to the work group. This white paper is provided in Attachment 2 to this 

matrix. 

Prior to the work group meeting, SC&A performed a review of the white paper in Attachment 2 and distributed its evaluation 

of NIOSH’s white paper to the work group at the time of the meeting. Attachment 3 presents SC&A’s review of NIOSH’s 

white paper. Based on SC&A’s review of NIOSH’s white paper regarding Issue 4, SC&A accepts NIOSH’s report and 

recommends that this issue be designated as resolved. 

May 12, 2010, Work Group Meeting: Chairman reaffirmed that Issue 4 had been resolved. 

Board Action: 
Updated TBD-6000 Issues Matrix 4 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Issue 5: Concerns with Method Used to Derive Surface Contamination and Associated External Doses 

SC&A Finding: SC&A has several concerns with the method used to derive the surface contamination and associated 

external doses in Table 6.4 of the TBD. Our primary concerns are the assumptions that the surface contamination levels are 

directly proportional to the airborne dust loading of respirable particles of uranium, and that the constant of proportionality

makes use of a respirable particle deposition velocity of 0.00075 m/sec and an arbitrary time period of deposition of 7 days. 

The various reports summarized in Attachment 1 to this report reveal that surfaces at uranium metal-working facilities 

become contaminated primarily from the deposition of relatively large flakes of uranium oxide produced during the rolling, 

machining, and general handling of uranium metal. These flakes fall directly onto surfaces, rather than slowly becoming 

deposited, as is the case for smaller particles in the air. The TBD should consider the empirical data regarding surface 

contamination reported in the Adley et al. report (AEC 1952) and the Simonds Saw and Steel report (ORAUT 2005), which 

provide information indicating that the default upper-bound uranium dust loading on surfaces, as recommended in the TBD 

for AWE facilities involved in uranium metal-working operations during the early years, might be underestimated by 1 to 2 

orders of magnitude. As a result, default external exposures from contaminated surfaces and internal exposures from the 

inhalation of resuspended particles of uranium deposited on surfaces might also be underestimated by 1 to 2 orders of 

magnitude. 

NIOSH Response: There appear to be two issues in this comment. First the issue of flakes. Large flakes of uranium that are 

produced would fairly quickly be ground into dust under foot and forklift traffic typical of operating area. They would then 

be available for resuspension and contribute to the air concentrations measured. This implies a connection between airborne 

concentrations and surface contamination often represented by a resuspension factor. If an abundance of large flakes present 

on the floor are not ground into dust quickly, it would imply a lower resuspension factor than might exist in an area free of 

large flake contamination. This implies this issue is closely related to the next comment and it is recommended that they be 

combined. 

The second issue indicates that the surface contamination in the TBD may be underestimated by one or two orders of 

magnitude and recommends considering the data contained in the Adley report. NIOSH performed a cursory review of the 

empirical data in Adley. The review indicates that the methods utilized in the TBD would overestimate the measured settling 

rates in Adley. 

SC&A Reply: SC&A believes that it is important to separate operational data that characterize the levels of surface 

contamination at AWE uranium handling facilities and generic literature that addresses indoor resuspension factors. The 

AWE literature on the buildup of uranium on surfaces, as described in Section 6.1.2 of SC&A’s review of TBD-6000, reveals 

that the default surface contamination recommended in TBD-6000 is not claimant favorable. For example, based on the 

investigations cited in AEC 1952, it will only require about 3 days of uranium processing before the surface contamination 

can build up to the default surface contamination level recommended in TBD-6000. We believe that NIOSH should revise 

TBD-6000 to explicitly consider the extensive data described in AEC 1952. SC&A recommends that this issue remain open.

October 14, 2009, Work Group Meeting: This issue was discussed at the October 14, 2009, work group meeting. Prior to 

the meeting, NIOSH distributed a white paper to the work group. This white paper is provided in Attachment 4 to this 

matrix. 

Prior to the work group meeting, SC&A performed a review of the white paper in Attachment 4 and distributed its evaluation 

of NIOSH’s white paper to the work group at the time of the meeting. Attachment 5 presents SC&A’s review of NIOSH’s 

white paper. 

Based on SC&A’s review of NIOSH’s white paper regarding Issue 5, SC&A accepts NIOSH’s report with respect to the 

methods used to estimate the contamination level on surfaces and recommends that this aspect of this issue be designated as 

resolved. This conclusion is important, because it is applicable to SC&A comments on numerous procedures and dose 

reconstruction reviews. SC&A previously believed that the deposition velocity approach adopted by NIOSH would 

underestimate accumulation of material on surfaces. However, SC&A’s review of the data in the Adley report reveals that 

this approach is scientifically sound. 

May 12, 2010, Work Group Meeting: The Chairman noted that this issue had been closed previously. 

Board Action: 
Updated TBD-6000 Issues Matrix 5 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Issue 6: Underestimate of Resuspension Factor 

SC&A Finding: In order to derive upper-bound default inhalation exposures due to the resuspension of uranium particles 

deposited on surfaces, the TBD uses a default resuspension factor of 1 × 10-6 per meter. A review by SC&A of the literature 

addressing resuspension factors indoors reveals that this value might be low by about an order of magnitude. Considering 

that the default bounding surface contamination used in the TBD might be low by 1 to 2 orders of magnitude, and that the 

default bounding resuspension factor might be low by an order of magnitude, the default inhalation rate and associated doses 

associated with the dust resuspension pathway might be underestimated in the TBD by several orders of magnitude. 

NIOSH Response: There is little specific information related to resuspension factors in the SC&A review of this TBD. As 

such, insufficient detail is provided to allow NIOSH to address the comment. It is suspected that the details appear in the 

SC&A review of OTIB-70. 

SC&A Reply: NRC (2002) recommends the use of a resuspension factor of 1 × 10-6 per meter for screening analyses to 

determine if a building can be released for unrestricted occupancy. There are two key assumptions that underlie the use of 

such a value. First, the surface contamination occurred sometime in the past, and no new contaminants are being introduced. 

Second: 

It is assumed that surfaces will be cleaned or washed during decommissioning. This will remove most of the 

loosely bound and some of the more tightly bound particles. Following the above discussion, surfaces that have 

been cleaned would be expected to have a smaller RF than surfaces that have not been cleaned, given the same 

levels of surface contamination. (NRC 2002, p 4)

Clearly, neither of these assumptions apply to an operating facility that performs work on uranium or thorium metals. 

Attachment 1 presents an excerpt from previous literature reviews performed by SC&A on behalf of the Board related to 

resuspension factors. We believe we have demonstrated that 1E-6 per meter is low by a factor of at least 10, especially for 

facilities that have not been cleaned up, where there is a lot of anthropomorphic activity, and your intention is to be claimant 

favorable. 

May 12, 2010, Work Group Meeting: The chairman stated that this issue had been transferred to the Procedures Work 

Group. 

Board Action: 
Updated TBD-6000 Issues Matrix 6 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Issue 7: Use of Deficient Methodology For Estimating Inadvertent Ingestion of Uranium 

SC&A Finding: Internal doses associated with the inadvertent ingestion of uranium are derived in the TBD using models 

and assumptions that have been discussed with NIOSH in the past as part of the review of numerous site profiles and 

exposure matrices. Based on these discussions, it is our understanding that NIOSH would agree that the basic methodology 

described in the TBD is deficient and should be revised when the overall revised methodology is developed. 

NIOSH Response: As the comment indicates, this methodology is the subject of numerous reviews and has been taken up 

as an overarching issue. If the methodology is changed as a result, the change will be incorporated into this TBD. 

SC&A Reply: SC&A raised this issue in our review of dose reconstructions in December 2004. At that time, NIOSH 

agreed to consider the inadvertent ingestion rates in EPA 1997 in their response to our comments. We have raised this issue 

repeatedly over the next 4 years, and it has still not been resolved. The bottom line is NIOSH is effectively assuming a 

default inadvertent ingestion rate of contaminated residue, soot, etc of 0.5 mg/day. Others (EPA and NCRP) have suggested 

50 to 100 mg/day. Notwithstanding whether we assume 0.5 or 50 mg/day, the exposures associated with the inadvertent 

ingestion pathway are small, relative to the inhalation pathway. Nevertheless, is would be desirable to close out this issue. 

October 14, 2009, Work Group Meeting: This subject was discussed at the October 14, 2009, work group meeting. 

NIOSH agreed that the inadvertent ingestion of “soot” may, in fact, be as high as 50 to 100 mg/day, but it is inappropriate to 

conclude that this material is entirely composed of the radionuclide of concern. SC&A accepts this position. NIOSH further 

argued that the 0.2 rule is appropriate, as delineated in OTIB-009. Using this approach, the daily ingestion rate of a 

radionuclide is derived by multiplying the radionuclide concentration in air (expressed in units of Bq/m3

 or mg/m3) by 0.2 to 

obtain the daily ingestion rate of the radionuclide (expressed in units of Bq/day or mg/day, depending on the units that are 

used to characterize the airborne concentration of the radionuclide). SC&A explained that this approach seemed to be 

reasonable, especially if the dust loading is high. For example, if a uranium facility has a dust loading of uranium of 

100 mg/m3

, the 0.2 rule would result in an ingestion rate of 20 mg/day of uranium. SC&A believes that this is reasonable. 

If the dust loading were much lower, let us say 1 mg/m3

 of uranium, the inadvertent ingestion rate would be derived as 

0.2 mg/day. SC&A argued that this is a very low ingestion rate. However, NIOSH explained that, any uranium on surfaces 

at such a facility would mix with non-radioactive soot on surfaces and, as a result, though the inadvertent ingestion rate of 

“soot” might be as high as 50 to 100 mg/day, it is unlikely that it would be pure uranium. SC&A accepts this position. 

Hence, SC&A concurs with NIOSH’s position on this matter, with one proviso. If a uranium facility is known to have 

extensive surface contamination, where large quantities of uranium are present on surfaces; i.e., visible quantities, we suggest 

that NIOSH consider using a default uranium ingestion rate of 50 mg/day under such circumstances. 

SC&A recommends that this issue remain open until the work group has an opportunity to discuss the aspect of this issue 

which deals with uranium facilities where there is heavy contamination of virtually pure uranium (or its various chemical 

forms) on surfaces.

May 12, 2010, Work Group Meeting: There was extensive discussion on this issue. SC&A felt that when high air 

concentrations existed, the NIOSH model linking air concentrations to ingestion would result in reasonable ingestion rates. 

However, SC&A envisioned situations where high uranium surface concentrations existed, which could lead to high 

ingestion, but concomitant high airborne exposures might not occur, thereby underestimating ingestion exposure with the 

NIOSH model. NIOSH felt that situations where high surface concentrations were not associated with high airborne 

concentrations were unlikely to occur. The Chairman concluded that this was a TIB-0009 issue and, accordingly, was 

outside the scope of the TBD-6000 Work Group. 

Board Action: 
Updated TBD-6000 Issues Matrix 7 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

References 

AEC 1952. Adley, F.E., Gill, W.E., and Scott, R.H., “Study of Atmospheric Contamination in 

the Metal Melt Building,” U.S. Atomic Energy Commission, HW-23352 (rev.), April 4, 1952. 

Allen, David 2009. “BATTELLE-TBD-6000 ISSUE 1 WHITE PAPER – Consideration of 

Recasting Increasing Progeny Concentration.” NIOSH/OCAS. December 10, 2009. 

Allen, David 2010. White Paper TBD-6000 Working Group – Putzier Effect.” NIOSH/OCAS. 

September 2010. 

 

Harris, W.B. and I. Kingsley 1959. “The Industrial Hygiene of Uranium Fabrication,” A.M.A. 

Archives of Industrial Health, Vol. 19, May 1959. pp. 76–101. 

ORAUT 2005. ORAUT-TKBS-0032, “Site Profile for Simonds Saw and Steel,” Revision 00 

PC-1, Oak Ridge Associated Universities Team. July 8, 2005. 

Putzier, E.A. 1982. “The Past 30 Years at Rocky Flats: A Summary of Experiences and 

Observations at Rocky Flats Plant Over the Past 30 Years with Emphasis on Health and Safety.” 

SC&A 2009. “Review of NIOSH Issue 1 White Paper Dated December 10, 2009.” Not PA 

Cleared. December 28, 2009. 
Updated TBD-6000 Issues Matrix A1-1 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ATTACHMENT 1: RESUSPENSION FACTORS 

The resuspension of radioactive material from surfaces can be modeled by the use of an 

equilibrium resuspension factor (RF) (in units of length-1). The RF is simply a ratio of the air 

concentration of radioactive material above a surface (Bq/m3

) to the concentration on the surface 

(Bq/m2

). 

Measured RFs vary over very wide ranges. Kennedy and Strenge (1992) reported RFs from 

approximately 1E-11 to 1E-2 m-1, which suggests that resuspension is a complex process of 

several parameters, and that the specific conditions present at the time of measurement are 

critical. For modeling purposes, an RF is a lumped parameter that is used to account for a 

complex combination of mechanisms that are poorly understood, but whose net effect is 

observed in the real world. 

The RF is affected by a number of physical factors that include the following: 

 • Type of disturbance 

 • Intensity of disturbance 

 • Time since deposition 

 • Nature of the surface 

 • Particle size distribution 

 • Climatic conditions 

 • Type of deposition 

 • Chemical properties of the contaminant 

 • Surface chemistry 

 • Room geometry and characteristics 

A general discussion of these factors is provided in Beyeler et al. (1999).

When choosing an appropriate value for RF, one must consider the nature of contamination on 

the surface (e.g., how tightly it is bound to the surface), and balancing the driving forces that 

cause the material on the surface to become airborne with the mechanisms that remove the 

material from the air. Clearly, the concept of RFs applies to solid particles and does not apply to 

gases. 

The primary force that will resuspend particles in occupancy and reuse scenarios can be expected 

to be mechanical forces associated with rubbing and abrasion of surfaces. These forces are 

typically associated with human activity. In buildings, air currents caused by normal ventilation 

or by vibrations are not expected to be a major cause of resuspension of particles (NUREG1720). Moreover, RFs determined from mechanical disturbance can be an order of magnitude 

higher than RFs determined with only air currents (Beyeler et al. 1999). Higher RFs were 

measured when driving forces were increased and when surface contamination was loose and 

easily removable (NUREG-1720). It is important to assess the types and intensity of the applied 

driving forces in order to select appropriate RF values for any dust inhalation exposure scenario. 
Updated TBD-6000 Issues Matrix A1-2 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Although ventilation does not cause significant resuspension, it will cause removal of already 

resuspended particles in two ways. The first is by outflow of air from a space such as a room or 

truck cab. The second is by turbulent inertial impaction caused by the change of direction of air 

streams as the air goes around obstacles. These removal mechanisms are important because they 

will reduce the airborne concentration and thus the RF. Resuspension factors based on studies 

with no ventilation will tend to be higher. Conversely, RF values taken from studies with 

excessive ventilation will be lower. 

How the surface radioactivity is bound to the surface will have a major effect on the RF. For 

particles to become airborne, the bond between the particles and the surface (e.g., floor or wall) 

must be broken by the driving forces. Particles that are tightly bound to the surface are not easily 

resuspended, whereas particles that are loosely bound, like freshly deposited material, will be 

more easily resuspended. Tightly bound particles require greater mechanical force to break the 

bonds and become resuspended. For the same amount of surface radioactivity, surfaces with a 

large portion of tightly bound particles will yield smaller RFs. 

Consideration of the representativeness of the surface radioactivity is important in selecting 

appropriate RF values. For the recycle and reuse of contaminated material, it should be assumed 

that the surfaces are cleaned or washed before release for unrestricted use. This cleaning will 

remove most of the loosely bound and some of the more tightly bound particles (NUREG-1720). 

As discussed in Beyeler et al. (1999), resuspension is greatest for smaller diameter particles. The 

RF decreases with particle diameter in the range of 1 to 5 microns. The distribution of particle 

size may also change with time as mechanical forces are applied. 

Although larger particles may be resuspended, gravitational settling removes them from the air 

more rapidly than smaller particles. Nevertheless, larger particles can be important because they 

can be measured as “removable” by wipe tests, leading to the conclusion that a higher fraction of 

resuspendable particles may be present that can actually contribute to dose. In this context, 

significant removable activity as larger particles may cause the RF to be underestimated 

(NUREG-1720). Since the RF is a ratio, the numerator is set equal to the measured airborne 

concentration, whereas the denominator is set equal to the measured surface activity. 

Unfortunately, there are no experimental data that specifically address resuspension from tools or 

equipment. The experimental data and recommendations summarized in Table 1 are felt to be 

the most appropriate available information. The range of RFs cited in Table 1 is 2 E-8 m-1 to 

4 E-3 m-1. The reported data are generally from experiments that examined resuspension of 

liquid or powder contaminated material that had been uniformly applied to clean surfaces in a 

laboratory-like setting. The highest values are typically associated with inefficient ventilation, 

excessive mechanical disturbance, or dusty conditions. Typically, the purpose of these studies 

was to help determine radiation protection safety guidelines for loose residual, surface 

radioactivity. 

One recent study performed by the NRC staff (NUREG-1720) used published literature and 

extensive field measurements at two decommissioning facilities to determine RF values for 

building occupancy at decommissioned facilities. As a result of their study, an improved basis to 
Updated TBD-6000 Issues Matrix A1-3 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

estimate indoor RFs has been established. The staff conducted statistical analysis of RF mean 

values for five sites deemed applicable to building occupancy after decommissioning. The staff 

believes that the available data are not perfect and tend to overestimate the likely RFs at 

decommissioned facilities. Their recommended values for RF should be used for building 

occupancy, but may be high for equipment reuse scenarios. 

Lower-end values for reuse scenarios are considered appropriate because of two key assumptions 

inherent in the scenario definition: (1) readily removable contamination has been removed from 

the surface of the recycled equipment or material prior to clearance, and (2) contamination that is 

not readily removable is the least susceptible to resuspension. This situation represents a key 

difference between this scenario and the conditions for which resuspension measurements have 

typically been taken. 

Table 1. Representative Reported Indoor Resuspension Data and Recommended Values

Reference Resuspension factor or range Comments

Barnes (1959) 4E-5 m-1 (confined space) 

2E-6 m-1 (open air) 

Reported for “dusty operations”; 10-5 m-1 recommended for 

most laboratory work. 

Stewart (1964) 1E-6 m-1 (quiescent 

conditions) 

1E-5–1E-4 m-1 (“operational” 

conditions) 

Notes that excessively high particulate resuspension values 

indoors are likely to indicate some degree of inefficiency in 

the ventilation system. 

Brunskill (1964) 2E-4–4E-3 m-1 Measured in small rooms with various types of personnel 

movement, including introduction of loose contamination on 

coveralls. Lower recommended values were measured for a 

large area of “loose” contamination on concrete; “much 

smaller” values were found for linoleum floor. 

Jones and Pond 

(1964) 

2E-8–5E-5 m-1

5E-5 m-1 (recommended for 

worst practical conditions) 

Estimated that 10%–20% of total airborne radioactivity was 

respirable. Suggested that recommended value could be an 

order of magnitude lower for average conditions. 

Dunster (1964) 2E-6–4E-5 m-1

2E-6 m-1 (recommended safe 

value for long-term use) 

Highest values from digging through dusty building rubble 

and in an enclosed and unventilated space. 

Spangler and Willis 

(1964) 

4E-5 m-1 (derived) This value is calculated using equation for equilibrium 

airborne concentration in a small room from a surface 

concentration and recommended values appropriate for 

calculating 40-hr maximum permissible concentration (MPC) 

levels. 

Healy (1971) 2.1 E-7–1.0 E-3 m-1(derived) This value is calculated using the equation for airborne 

concentration, assuming ventilation rate for a reasonably 

tight 28 m2 2.4 m room. 

Gibson and 

Wrixom (1979) 

2E-6–4E-5 m-1 The lower value was used in original calculation of derived 

working limits (DWL) for active area surfaces and might be 

inappropriate for widespread contamination on dusty 

surfaces. The higher value was obtained from measurements 

in a confined space and is suggested for general use. 

IAEA (1970) 2E-6–3E-3 m-1

5E-5 m-1 (recommended) 

Recommended value is suggested as appropriate for general 

conditions of contamination on surfaces. Because of 

confounding factors, this effectively reduces the 

recommended value by 2.5 for use in calculating DWL 

values. 

Kennedy et al. 

(1981) 

2.5E-5 m-1 (derived) This value is calculated using the equation for airborne 

concentration, assuming ventilation rate of an open transport 

truck and resuspension rate for a 28 m2

 room. 
Updated TBD-6000 Issues Matrix A1-4 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Table 1. Representative Reported Indoor Resuspension Data and Recommended Values

Reference Resuspension factor or range Comments

Kennedy and 

Strenge (1992) 

1E-6 m-1 (recommended) Based on a review of resuspension literature. Recommended 

as a reasonably conservative default value to be applied to 

total surface concentration. 

IAEA (1992) 1E-6 m-1 (recommended) This value is recommended for use in assessing reuse of tools 

and equipment. Used a transfer factor of 0.01 to account for 

the fraction of the residual surface radioactivity that is 

available for resuspension. 

Chen (1993) 1 E-6 m-1 No justification given (based on use in Kennedy and Strenge 

1992)

Draft NUREG1720 (2002) Lognormal distribution with 

mean of 3.7 E-7 m-1 and 90th

percentile of 9.6 E-7 m-1

NRC staff analyzed literature and recent field data 

considering realistic assumptions about decommissioned 

facilities and building occupancy for the DandD code. 

Resuspension factor values best represent cleaned and aged 

surfaces. 

The use of RFs near the lowest measured value is also justified based on consideration of the 

respirable fraction of resuspended contamination. In one of the few studies where particle size 

has been measured, Jones and Pond (1964) reported that measurements of air concentration were 

often biased by a few highly active large particles. In their study on resuspension of plutonium, 

they concluded that only 10 to 20 percent of the total airborne radioactivity would be respirable. 

Another complicating factor is that the residual surface radioactivity is probably not uniform. 

Several studies (Dunster 1964, IAEA 1970, Healy 1971) discuss how this issue relates to 

resuspension values. Healy (1971) points out that in most cases, resuspension has been 

measured for uniformly contaminated surfaces and uniformly applied resuspension forces. 

Healy suggests that air concentrations are more strongly related to the total amount of surface 

contamination present, rather than the amount on any one limited area, and that basing allowable 

surface contamination limits on the highest surface levels may be too conservative. 

There are many other factors that contribute to the uncertainty in resuspension that are not 

addressed here because of lack of information. These include temperature, humidity, type and 

roughness of surface material, degree and effectiveness of mechanical disturbance, weathering 

processes, and chemical state of the contamination. The effect of changes in many of these 

factors on resuspended air particle concentrations is intuitive (e.g., an increase in the size of the 

contaminated area would likely result in an increase in the resuspended air concentration); 

however, the degree and direction of the effect of other factors (e.g., specific surface conditions) 

is not so clear. Combining all these factors to define a “generic” RF or rate for modeling 

purposes is difficult. Based on consideration of these factors and good engineering judgment, 

however, it is reasonable to use a lognormal distribution with geometric mean of the lowest 

reported RF in the model. 
Updated TBD-6000 Issues Matrix A1-5 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

References 

Barnes, D.E., 1959. “Basic Criteria in the Control of Air and Surface Contamination,” 

Symposium on Health Physics in Nuclear Installations, at Riso, Denmark, 25-28 May 1959. 

Organization of European and Economic Cooperation/European Nuclear Energy Agency, Paris, 

1959. 

Beyeler et al. 1999. Residual Radioactive Contamination from Decommissioning, Parameter 

analysis. Draft Report for Comment, NUREG/CR-5512, Vol. 3. U.S. Nuclear Regulatory 

Commission. 

Bond, R.G., Straub, C.P., and Prober, R. 1972. Air Pollution, Vol. 1 of Handbook of 

Environmental Control. Cleveland, Ohio: CRC press. 

Brunskill, R.T., 1964. The Relationship Between Surface and Airborne Contamination, Surface 

Contamination, Proceedings of a Symposium Held at Gatlinburg, Tennessee, June 1964. 

Pergamon Press, Oxford, 1967. 

Chen, S.Y., 1993. Risk Assessment Bases on Current Release Standards for Radioactive Surface 

Contamination, ANL/EAIS/CP-79677. Argonne National Laboratory, Argonne, Illinois, 

September 1993. 

Dennis, R. 1976. Handbook of Aerosols. TID 26608. U.S. ERDA, Washington, DC. U.S. 

ERDA Dennis, R. 1976. Handbook of Aerosols. TID 26608. U.S. ERDA, Washington, DC. 

U.S. ERDA. 

Dunster, H.J., 1964. “The Concept of Derived Working Limits for Surface Contamination,” in 

Surface Contamination, Proceedings of a Symposium Held at Gatlinburg, Tennessee, June 

1964. Pergamon Press, Oxford, 1967. 

First, M.W. and Drinker, P. 1952. “Concentrations of Particulates Found in Air.” Arch. Ind. 

Hyg. Occup. Med. 5:387. 

Gilbert, T.L., et al. 1983. “Pathways Analysis and Radiation Dose Estimates for Radioactive 

Residues at Formerly Utilized MED/AEC Sites. ORO-832 (Rev). 

Healy, J.W., 1971. Surface Contamination: Decision Levels, LA-4558-MS. Los Alamos 

Scientific laboratory, Los Alamos, New Mexico, September 1971. 

IAEA 1970. International Atomic Energy Agency. Monitoring Radioactivity on Surfaces, 

Technical Report Series No. 120. International Atomic Energy Agency, Vienna, 1970. 

Jones, I.S. and S.F. Pond, 1964. “Some Experiments to Determine the Resuspension of 

Plutonium from Various Surfaces, “ in Surface Contamination, Proceedings of a Symposium 

Held at Gatlinburg, Tennessee, June 1964. Pergamon Press, Oxford, 1967. 
Updated TBD-6000 Issues Matrix A1-6 SC&A – October 7, 2010

 This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a

NOTICE: 

) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Kennedy, W.E. and D.L. Strenge, 1992. Residual Radioactive Contamination from 

Decommissioning: Volume 1, Technical Basis for Translating Contamination levels to Annual 

Total Effective Dose Equivalent, NUREG/CR-5512. Prepared by Pacific Northwest Laboratory 

for the U.S. Nuclear Regulatory Commission, Washington DC. December 1992. 

Linch 2002., Linch, KD. “Respirable concrete dust-silicosis hazard in the construction 

industry,” Appl Occup Environ Hyg Mar; 17(3):209-21, 2002. 

Oztunali, O., et al. 1981. Data Base for Radioactive Waste Management, Impacts Analyses 

Methodology Report. NUREG/CR-1759. Washington, DC: U.S. NRC. 

Schwendiman, L.C. 1977. Supporting Information for the Estimation of Plutonium Oxide Leak 

Rates Through Very Small Apertures, BNWL-2198. Richland, Washington: Pacific Northwest 

Laboratory. 

Sinclair 1976., Sinclair, P.C. “Vertical Transport of Desert Particulates by Dust Levels and 

Clear Thermals,” Proceedings of the Atmospheric-Surface Exchange of Particulates and 

Gaseous Pollutants– 1974 Symposium, pp 497-527, USERDA, CONF-740921, NTIS, 

Springfield, VA. 1976. 

Spangler, G.W., and C.A. Willis, 1964. “Permissible Concentration Limits,” in Surface 

Contamination, Proceedings of a Symposium Held at Gatlinburg, Tennessee, June 1964. 

Pergamon Press, Oxford, 1967. 

Stern, A.C. 1976. “Air Pollution,” In: Air Pollutants, Their Transformation and Transport. 

Volume 1. New York: Academic Press. 

Stewart, K., 1964. “The Resuspension of Particulate Material from Surfaces,” in Surface 

Contamination, Proceedings of a Symposium Held at Gatlinburg, Tennessee, June 1964. 

Pergamon Press, Oxford, 1967. 

Sutter, S.L. 1982. Accident Generated Particulate Materials and Their Characteristics - A 

Review of Background Information, NUREG/CR-2651. Battelle Pacific Northwest Labs., 

Richland WA. 

United Power Association (UPA) 1974. Final Elk River Reactor Program Report, COO-651-93. 

Elk River, Minnesota. 

Yu et al. 1993. Data Collection Handbook to Support Modeling the Impacts of Radioactive 

Material in Soil. ANL/EAIS-8. Environmental Assessment and Information Division, Argonne 

National Laboratory.
Updated TBD-6000 Issues Matrix A2-1 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ATTACHMENT 2: NIOSH COMMENTS ON ISSUE 4 

BATTELLE-TBD-6000 ISSUE 4 WHITE PAPER 

Comparison to Adley Air Data 

Prepared by Dave Allen, OCAS 

October 9, 2009 

Issue 4 of the Battelle-TBD-6000 review matrix recommended comparing air exposure values in 

the TBD to time-weighted air exposure values in the report by Adley et al. (1952) and the 

Simonds Saw Steel site profile. This white paper provides that comparison. 

Review of Adley Data 

The Adley et al. report provides nine time-weighted average air exposure values in Table IX. 

The values are presented in units of x10-5 ug-hrs/cc. In order to compare these values to TBD6000, the values were first converted to an average air concentration value by dividing the daily 

time-weighted value provided in Adley by 8 hours. The values were next converted to units of 

pCi/m3, then to annual exposures and finally divided by 365 calendar days. This resulted in units 

of pCi/calendar day exposure, which are the units used in TBD-6000. 

These values are provided in the Table below along with those from TBD-6000. 

Job Title pCi/calendar day 

Adley 

Furnace Operator 8221

Furnace Assistant 3354

Saw Room Operator 11574

Oxide Operator 33816

Rod Handler 1047

Autoclave Operator 218

Rod Receiving-unloading 2944

Rod Receiving-weighing 316

Rod Receiving-stacking 1244

Battelle-TBD-6000 

Extrusion Operator 2965

Rolling Operator 10559

Forging Operator 3497

Machining Operator 16379

Slug Production Operator 592

Scrap Recovery Operator 5051

The values in TBD-6000 are the geometric mean (GM) of a lognormal distribution with a 

geometric standard deviation (GSD) of 5. The values in Adley have no distribution listed so a 

comparison is difficult. In an attempt to compare the values analytically, a distribution of the 

Adley values was determined. This resulted in a log normal distribution with a GM of 

2420 pCi/day and a GSD of 5.3. The figure below shows the fit of the data. 
Distribution of Air Sample Results Reported in Adley

0

2

4

6

8

10

12

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

# of Standard Deviations

LN pCi/day

The table below list values for the six operations from TBD-6000. The GM values from 

Table 7.8 as well as the 95th percentile are listed. Also the GM and 95th percentile values from 

the Adley distribution above are listed. 

GM 95th

Adley 2420 37636

Battelle_TBD-6000 

Extrusion Operator 2965 41863

Rolling Operator 10559 149083

Forging Operator 3497 49374

Machining Operator 16379 231256

Slug Production Operator 592 8358

Scrap Recovery Operator 5051 71315

Five of the six GM values from TBD-6000 are higher than the GM of the Adley distribution. 

Also, the 95th percentile of the same five samples are also larger than the 95th percentile of the 

Adley distribution. 

Simonds Saw and Steel 

Simonds Saw and Steel rolled uranium rods for the AEC. The Health and Safety Lab (HASL) 

visited the site and took air samples on several occasions. As a result of these, HASL made 

recommendations for improving control of airborne uranium. The first day samples were take 

was October 27, 1948. Since these were taken before additional controls were put in place, these 

samples were used in the Bethlehem Steel TBD. An analysis of these samples found they fit a 

lognormal distribution with a GM of 1177 dpm/m3

 and a GSD of 8.36 which correlated to a 95th

percentile of 38,754 dpm/m3

. Putting this in the same units as above, the GM is 3487 pCi/day 

and the 95th percentile is 114,783 pCi/day. Comparing this to the Rolling Operator values in the 

Updated TBD-6000 Issues Matrix A2-2 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.
Updated TBD-6000 Issues Matrix A2-3 SC&A – October 7, 2010

 This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a

NOTICE: 

) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

TBD-6000 shows both the GM and the 95th percentile intake rates in TBD-6000 are higher than 

that derived from Simonds Saw and Steel data. 

Reference

Adley, F.E., Gill, W.E., Scott, R.H., Study of Atmospheric Contamination in the Melt Plant 

Building, USAEC report HW-233352(Rev.), April 4, 1952. 

Oak Ridge Associated Universities, Site Profile for Simonds Saw and Steel, ORAUT-TKBS0032 Rev. 00 PC-1, July, 8, 2005. 
Updated TBD-6000 Issues Matrix A3-1 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ATTACHMENT 3: SC&A COMMENTS ON ATTACHMENT 2 

SC&A REVIEW of NIOSH BATTELLE-TBD-6000 ISSUE 4 WHITE PAPER 

October 13, 2009 

SC&A conducted a brief review of the NIOSH Issue 4 White Paper dated October 9, 2009. 

During its review SC&A, spot checked various calculations in the Issue 4 paper and concurred 

with the results presented. 

In the Issue 4 Paper, NIOSH stated that “The values in Adley have no distribution listed so a 

comparison is difficult.” Actually, Adley et al. (1952) provide results of multiple air samples for 

various operations involving nine different job titles. However, it is not clear from Adley how 

the average concentrations reported in Table IX of that report were obtained from the individual 

measurements reported elsewhere in Tables II through VIII. 

Consider, for example, the saw room operator, who is assigned an exposure of 

11,574 pCi/calendar-day in the Issue 4 Paper. This is based on a weighted daily exposure of 

2,233 × 10-5 μg-hr/cc from Table IX in Adley et al. 1952. As shown in Table 1 below, the 

average concentrations reported in Table IX (column 3) often do not agree with the averages of 

the actual measurements calculated in column 6. We do not know why the results are different. 

The calculated averages from the individual measurements (column 6) are generally higher than 

the average values from Table IX of Adley (column 3). Using the averages of the individual 

measurement would increase the weighted daily exposure from 2,223 × 10-5 μg-hr/cc to 4,115 × 

10-5 μg-hr/cc. 

Table 1. Weighted Daily Exposures to Saw Room Operator 

Operation 

Daily Time 

for 

Operation 

(hr) 

Average 

Concentration 

per Adley 

Table IX 

(10-5 μg/cc) 

Number of 

measurements 

Measurements 

per Adley Table 

III 

(10-5 μg/cc) 

Calculated 

Average 

from 

Column 5 

(10-5 μg/cc) 

Weighted 

Daily 

Exposure 

(10-5 μghr/cc) 

stripping 

billets 

0.4 19.1 4 0.9, 15, 22, 43 20.2 7.6 

sawing 3.0 67 7 87, 92, 12, 59, 

286, 154, 122 

116 201 

lathing 0.2 37 5 442, 27, 4.3 97, 

20 

118 7.4 

grinding 0.3 5450 2 23,800, 55 11,928 1635 

sweeping 0.1 86 1 86 86 8.6 

miscellaneous 3.5 4.0 5 5.3, 0.4, 127, 10, 

18 

32.1 14 

furnace room 

help 

0.5 717 6 147, 85, 58, 62, 

79, 6.2 (Adley 

Table II) 

72.9 359 

Use of the averages of the individual measurements results in higher exposures than the averages 

cited by Adley et al. in Table IX. However, as shown in the Issue 4 Paper, the results from 
Updated TBD-6000 Issues Matrix A3-2 SC&A – October 7, 2010

 This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a

NOTICE: 

) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Adley et al. based on Table IX are generally lower than those in TBD-6000. Consequently, use 

of the higher exposure values based on averages of the actual measurements is not inconsistent 

with those presented in TBD-6000. 

Reference 

Adley, F.E., Gill, W.E., Scott, R.H., Study of Atmospheric Contamination in the Melt Plant 

Building, USAEC report HW-233352(Rev.), April 4, 1952. 
Updated TBD-6000 Issues Matrix A4-1 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ATTACHMENT 4: NIOSH COMMENTS ON ISSUE 5 

BATTELLE-TBD-6000 ISSUE 5 WHITE PAPER 

Comparison to Adley Contamination Data 

Prepared by Dave Allen, OCAS 

October 9, 2009 

Issue 5 of the SC&A review of TBD-6000 recommended considering the surface contamination 

levels reported in the report by Adley et al. (1952) as well as the Simonds Saw and Steel TBD. 

SC&A’s comment questioned the appropriateness of using a 0.00075 m/s settling rate, as well as 

the use of 7 days deposition time. This white paper provides a review of the data in Adley and 

Simonds Saw with regard to these issues. 

Review of Adley Data 

In the study reported in Adley, settling plates were placed in 13 locations throughout the Melt 

Plant building at Hanford. Uranium settling out of the air was allowed to accumulate for 158 

days during the winter. The plates were removed for analysis and replaced with more plates for 

an additional 117 days during the spring. The winter period represented a time when the doors 

were kept closed, while the spring period represented a time when the doors were generally left 

open. The total uranium content of each plate was divided by the area of the plate and the 

number of days it was exposed to determine a settling rate in mg of uranium per square foot per 

day. 

Four plates from the spring time period were lost due to breakage or other accidental causes. 

This left 9 plates that were in place during both winter and spring months. Table XIII of the 

report provides the results for the winter and spring settling samples. Six of the nine samples are 

higher for the 117 days than the 158 days but generally within a factor of 2. This indicates little 

difference between the 158 day exposure and the 117 day exposure, which implies a buildup 

period ends before 117 days even without some of the typical removal factors (foot traffic, house 

cleaning, etc.). 

The lowest settling rate determined in Adley was 0.21 mg/ft2

/day recorded in an office area. The 

highest rate (5.72 mg/ft2/day) was recorded in the Burnout Room. The burnout room appears to 

be one of the higher airborne areas in the facility while the office area is likely one of the lowest. 

This implies that the amount of contamination settling on the plates is generally correlated with 

airborne levels. 

Adley Settling Rate 

Adley recorded settling rates in units of mg/ft2/day. In order to determine a settling rate that can 

be compared to the 0.00075 m/s rate used in TBD-6000, it is necessary to know the airborne 

activity. It is difficult to use Adley for this purpose for two reasons. First, Adley measured 

airborne activity for the purpose of determining exposure to various operators in the facility. 

This means that the airborne levels during the various tasks were determined but no airborne 
concentrations were measured at other times. This is a problem because the settling plates would 

be collecting uranium at all times whether or not an operation was occurring in the vicinity. This 

can be illustrated by reviewing the airborne concentrations during the highest two operations in 

Table IX of Adley. These are grinding in the saw room and loading and unloading oxide furnace 

trays. These operations occurred for 18 minutes and 30 minutes per day respectively. Even 

though air concentrations were high during these short evolutions, this airborne activity would 

contribute to the settling plates for only a limited time. 

The use of daily time-weighted exposures can help to resove this issue by accounting for the 

amount of time the airborne generating operation occured. This, however, creates a second 

problem, which is that daily time-weighted airborne exposures are based on the operator rather 

than the areas. Some operators were required to move about the facility throughout the course of 

the day, so these values are not strictly associated with a specific area. However, much of the 

equipment in this building was located in an open area (the Main Bay) and 9 of the 13 settling 

plate locations were in this bay. Also, for the spring measurements, Adley reported that the 

doors were generally left open. These factors would likely cause a general mixing throughout 

the building and, therefore, the average air activity in the building was likely affected by all tasks 

in the building. 

 

To compare settling rates from Adley with those from TBD-6000, the distribution of timeweighted air exposures from Adley was used. The distribution, which was determined in the 

white paper written for issue 4, was lognormally distributed with a geometric mean (GM) intake 

rate of 2420 pCi/day and a geometric standard deviation (GSD) of 5.3. The corresponding value, 

when converted mass, results in a value for the GM of 584 ug/m3

 with a 95th percentile 

concentration of 9076 ug/m3. The settling rates from Adley, reported in units of mg/ft2/day, were 

converted to ug/m2

/day. These values were then divided by 584 ug/m3 (the geometric mean of 

the time-weighted distribution) to determine the settling rates. This value was then converted to 

m/s so that it could be compared to the value used in TBD-6000. The derived values, 

represented by diamonds, are shown in the Figure 1 below. A horizontal line is drawn at 

0.00075 m/s to show the value used in TBD-6000. The circles represent the same derived 

values, if the 95th percentile value of the airborne activity is used. 

Comparison of Settling Rates Derived from Adley to TBD 6000

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0.0014

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

m/s

Updated TBD-6000 Issues Matrix A4-2 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.
Updated TBD-6000 Issues Matrix A4-3 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

The median value of these settling rates (determined using the Excel “median” function) is 

0.00023 m/s. 

Contamination Levels – Adley 

The settling rate derived above appears to indicate the 0.00075 m/s used in TBD-6000 is a 

reasonable value. However, contamination levels are determined by the combination of the 

settling rate and the deposition time. 

In Adley, plates were placed for 117 day and 158 days and a settling rate determined by dividing 

the uranium content by these times. It is therefore a simple matter to determine the actual 

contamination level on the plates at the end of the settling period. It is also a simple matter to 

use the airborne exposure values from TBD-6000 to determine the contamination levels 

associated with the operations (assuming a 7 day deposition and a 0.00075 m/s deposition rate). 

This analysis was done for both sets of data and lognormal distribution parameters determined 

for each. The median value for the TBD-6000 derived contamination levels was 3.8 times lower 

than the contamination levels derived from Adley. A GSD of 5 is applied to the external doses 

in TBD-6000 therefore this was used to determine a 95th percentile value for the TBD-6000 

contamination levels. When compared to the 95th percentile determined from the Adley 

distribution, it was determined that the Adley values are 1.01 times higher. 

Contamination Levels - Simonds Saw and Steel 

The SC&A review of TBD-6000 recommended considering values from the Simonds Saw and 

Steel TBD. During the Working Group meeting on March 11, 2009, twenty film badges that 

were hung in the Simonds Saw plant were mentioned. The Simonds Saw TBD discusses these 

badges and indicates that when they were collected they were heavily contaminated. While the 

radiation dose measured with these badges would include radiation from the contamination, they 

would also include direct radiation from uranium metal in the facility. There are surface 

contamination surveys of the Simonds Saw and Steel plant that would be much more appropriate 

to consider. The Health and Safety lab performed direct measurement contamination surveys at 

the plant on October 27, 1948 and December 1, 1948 during rolling operations. This is prior to 

instituting controls recommended by HASL. 

The measurements were converted to units of ug/m2

 and the parameters of a lognormal 

distribution determined from the set of data. When compared to the GM of the TBD-6000 data, 

it was found that the TBD-6000 data was 2.2 times lower than the Simonds Saw data. A 

comparison of the 95th percentile values indicates the Simonds Saw data was 82% that of the 

TBD-6000 values. 

Conclusions 

TBD-6000 used a 7 day deposition period when determining the surface contamination for 

external dose from surface contamination. However, section 7.1.5 of TBD-6000 indicates that 

for the purposes of airborne activity from resuspended surface contamination, a deposition 

period of one year was used. If the 0.00075 m/s settling rate is used, the necessary deposition 

time to match the Adley data would be either 27 day or 7.1 days based on the median and 95th
Updated TBD-6000 Issues Matrix A4-4 SC&A – October 7, 2010

 This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a

NOTICE: 

) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

percentile values respectively. The deposition time necessary based on the Simonds Saw data 

would be 15 day or 5.8 days. 

The highest external dose rate from surface contamination in Table 6.4 of TBD-6000 is 

0.009177 mr/day. The external dose rate from the uranium metal for the same task is 

6.84 mr/day. Therefore, the dose from surface contamination is 0.13% that of the dose from 

metal. The 3.8 factor derived from the Adley median value increases this to 0.52% while the 

95th percentile increases it to 0.14%. If the Simonds Saw values are used, the external dose from 

surface contamination would became 0.29% or 0.11% of the dose from uranium metal based on 

the GM and 95th percentile values, respectively. 

Reference

Adley, F.E., Gill, W.E., Scott, R.H., Study of Atmospheric Contamination in the Melt Plant 

Building, USAEC report HW-233352(Rev.), April 4, 1952. 

Oak Ridge Associated Universities, Site Profile for Simonds Saw and Steel, ORAUT-TKBS0032 Rev. 00 PC-1, July, 8, 2005. 
Updated TBD-6000 Issues Matrix A5-1 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ATTACHMENT 5: SC&A COMMENTS ON ATTACHMENT 4 

SC&A Review of NIOSH Issue 5 White Paper 

October 13, 2009 

This memorandum summarizes SC&A’s preliminary review of the NIOSH Issue 5 White Paper 

dated October 9, 2009. 

Use of Adley et al. 1952 to Estimate External Exposures from Contaminated Surfaces. 

Per Table 6.4 of TBD-6000, the geometric mean external exposure from contaminated floor 

surface for an operator working in scrap recovery (prior to 12/31/1950) is 2.83E-03 mR/day. 

(For perspective, exposures to other operators range from 3.31E-04 for slug production to 9.18E03 for machining). Per Table 3.10 of TBD-6000, the conversion factor for surface contamination 

is 4.49E-09 mR/d per dpm/m2. 

Adley et al. (1952, Table XIII) cite measured uranium settling rates for winter and spring 

samples. The median (geometric mean) value for the winter samples is 1.01 mg U/ft2/day and 

for the spring samples is 1.11 mg U/ft2/day. The winter sampling period was 158 days while the 

spring sampling period was 117 days. The settling rates in Table XIII are based on the 

assumption that deposition occurs linearly with time. There is no information in Adley et al. 

1952 to support the validity of this assumption. An alternate hypothesis, also unsubstantiated in 

Adley et al. is that the settling rates are based on a deposition/re-suspension equilibrium where 

the total quantity of uranium deposited (per unit area) is no longer changing. The total uranium 

deposited is an experimentally measured quantity with quantifiable uncertainty and can be used 

as a bounding quantity under the equilibrium assumption. 

Based on the above data, the total U deposition for the winter samples is 160 mg/ft2

 and for the 

spring samples is 130 mg/ft2. Using the winter sample data and assuming that the specific 

activity of natural uranium is 6.77E+05 pCi/g, the equivalent surface concentration is 

2.83E+06 dpm/m2

 (160 mg/ft2 × 1 g/1000 mg × 1 ft2/0.085 m2 × 6.77E+05 pCi/g × 

2.22 dpm/pCi). 

Using the dose conversion factor noted above the bounding exposure is 12.7E-03 mR/day 

(4.49E-09 mR/day per dpm/m2 × 2.83E+06 dpm/m2

). The exposure value is about 4.5 times 

higher than the value estimated in TBD-6000. If instead, one had assumed that the operations 

documented in Adley et.al 1952 were more akin to machining (which was certainly part of the 

operation) than the difference would be reduced to a factor of 1.4. 

Based on this analysis, it appears that the surface concentrations measured by Adley et al. (1952) 

result is similar, but slightly higher, exposure estimates to those based on TBD-6000. 

Note: According to TBD-6000, Section 6.1.3, the deposition period assumed calculating surface 

exposure is 7 days, and the air concentration experienced by a scrap recovery operator is 

1690 dpm/m3

 (TBD-6000, Table 7.7). On this basis, the surface contamination is 7.67E+05 
Updated TBD-6000 Issues Matrix A5-2 SC&A – October 7, 2010

 This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a

NOTICE: 

) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

dpm/m2 (1690 dpm/m3 × 0.00075 m/s × 604,800 sec). Alternatively, the surface contamination 

can be calculated based on the exposure of 2.83E-03 mR /day from TBD-6000, Table 6.4 and the 

surface contamination conversion factor of 4.49E-09 mR/day per dpm/m2 from Table 3.10 of 

TBD-6000 which results in a value of 6.3E+06 dpm/m2

. It is not known why the two 

calculations of surface contamination differ by about 20%. They should be identical. 

Other Comments on Issue 5 Paper 

In the section entitled Contamination Levels – Adley, NIOSH states that “This analysis was 

done for both sets of data and lognormal distribution parameters determined for each. The 

median value for the TBD-6000 derived contamination levels was 3.8 times lower than the 

contamination levels derived from Adley.” It is not clear what are the two sets of data to which 

NIOSH refers. This section requires some elaboration as to the data sets used and the nature of 

the calculations. Since NIOSH notes earlier in the Issue 5 paper that the median deposition 

velocity based on Adley et al. is lower than that used in TBD-6000 (i.e, 0.00023 vs. 

0.00075 m/s), it would seem that the contamination level based on Adley would also be lower. 
Updated TBD-6000 Issues Matrix A6-1 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ATTACHMENT 6: NIOSH ISSUE 1 WHITE PAPER 

BATTELLE-TBD-6000 ISSUE 1 WHITE PAPER 

Consideration of Recasting Increasing Progeny Concentration 

Prepared by Dave Allen, OCAS 

December 10, 2009 

Background 

Issue 1 of the SC&A review of TBD-6000 indicated that the TBD would benefit from a 

discussion of the possibility that recasting of uranium metal raises the concentration of Th-234 

and Pa-234m close to the surface of the ingots. SC&A referred to Putzier in describing this 

phenomenon. NIOSH responded in agreement that the TBD would benefit from the discussion. 

During the October 14, 2009 meeting of the Working Group, it was clarified that SC&A felt the 

issue was more than simply adding a discussion to the TBD. SC&A felt the phenomenon could 

cause shallow doses in TBD-6000 to be as much as a factor of ten higher. This white paper 

explores this issue by comparing the TBD-6000 values with the shallow dose at another facility 

that recast uranium. 

TBD-6000 

TBD-6000 provides deep and shallow dose rates for various uranium metal production tasks. 

The values are provided in Table 6.4 which indicates a deep dose rate of 5.7 mrem per calendar 

day and a shallow dose rate of 57 mrem per calendar day for a 2000 hour work year. These dose 

rates are the geometric mean of a lognormal distribution that has a geometric standard deviation 

of five. 

Fernald Data

Dosimeter data from the Fernald plant will be used for the comparison in this white paper. 

Fernald performed various tasks with several chemical forms of uranium. One of those tasks 

involved re-melting uranium metal and casting it into molds. The data set consists of annual 

doses from each employee between 1952 and 2006. A total of 124,113 individual annual doses 

were reviewed. 

Analysis 

Since the Fernald data includes operations other than recasting, a distribution of the shallow dose 

could be reduced by these other operations. Therefore, the maximum doses were compared to 

the 95th percentile of the TBD-6000 distribution. 

The results of these analyses are shown in the Table. The TBD-6000 doses were converted to 

annual doses. Both the maximum deep and the maximum shallow dose at Fernald are provided in 

the Table. These represent the maximum from any employee for any year. They are not from 

the same employee or the same year. 

Annual Dose in Rem 

Deep Shallow 

TBD-6000 – 95th 29.375 293.747

Fernald – max 12.300 52.000
Updated TBD-6000 Issues Matrix A6-2 SC&A – October 7, 2010

 This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a

NOTICE: 

) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

Conclusion 

The TBD-6000 doses at the 95th percentile exceed the maximum doses recorded at Fernald. 

While the phenomenon of increased shallow dose rates in recasting areas is well known, it 

appears other favorable assumptions in TBD-6000 account for this. 

Reference

Putzier, E. A. 1982. “The Past 30 Years at Rocky Flats: A Summary of Experiences and 

Observations at Rocky Flats Plant Over the Past 30 Years with Emphasis on Health and Safety.” 
Updated TBD-6000 Issues Matrix A7 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ATTACHMENT 7: SC&A WHITE PAPER – REVIEW OF NIOSH ISSUE 1 

WHITE PAPER DATED DECEMBER 10, 2009 

The version of the report attached here has been reviewed for Privacy Act-protected information 

and redacted accordingly. This PA-Cleared version was provided to the Work Group on January 

14, 2010. 
DRAFT WHITE PAPER 

REVIEW OF NIOSH ISSUE 1 WHITE PAPER 

DATED DECEMBER 10, 2009 

Contract Number 200-2009-28555 

Prepared by 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, Virginia 22182 

Saliant, Inc. 

5579 Catholic Church Road 

Jefferson, Maryland 21755 

December 2009 

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 predecisional and has not been reviewed by the Board for factual accuracy or applicability within the 

requirements of 42 CFR 82. 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.
White Paper – TBD-6000 Issue 1 2 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

In its review of Battelle-TBD-6000 (subsequently referred to here as TBD-6000), one of 

SC&A’s findings was as follows (SC&A 2007): 

(1) The TBD would benefit from a discussion of the possibility and potential 

dosimetric significance of uranium metal-working operations involving freshly 

cast uranium ingots, where there might be elevated levels of Th-234 and Pa-234m 

close to the surface of the ingot. Furthermore, it is not clear from the TBD 

whether scrap recovery at any of the covered AWE sites involved melting and 

casting of uranium. This should be investigated, since it could make a significant 

difference in the external dose reconstruction protocol.

NIOSH responded to this finding in BATTELLE-TBD-6000 ISSUE 1 WHITE PAPER: 

Consideration of Recasting Increasing Progeny Concentration, December 10, 2009 (see 

Appendix A). During the Work Group meeting held on December 16, 2009, there was extensive 

discussion regarding the degree to which the annual external exposure distributions adopted as 

default values in TBD-6000 capture the effect of elevated surface levels of Th-234 and Pa-234m. 

We also discussed whether, and the degree to which, these elevated levels of surface activity 

actually occurred at many facilities. This report is provided in response to NIOSH’s white paper 

on this subject, as requested by the TBD-6000 Work Group at its December 16, 2009, meeting. 

The discussion presented here is focused on TBD-6000 guidance for uranium fabrication 

operations. Elevated surface levels of Th-234 and Pa-234m also occurred in some of the 

uranium refining operations covered in TBD-6001. A different methodology for estimating 

doses is used in TBD-6000 than is used in TBD-6001. In its review of TBD-6001, SC&A 

described concerns related to external dose reconstruction used in that document (SC&A 2008). 

These should be addressed when that review is considered by the Work Group. However, we 

have provided a brief note at the end of this review comparing, but not reconciling, some of the 

guidance in TBD-6000 and TBD-6001. 

Background 

The concern about high beta radiation levels associated with the melting and casting of uranium 

was based in part on a document authored by Edward Putzier (1982), formerly Health Sciences 

manager at the Rocky Flats Plant, who observed that the surface beta dose from as-cast uranium 

ingots was about an order of magnitude greater than from a clean uranium surface in equilibrium 

with Th-234 and Pa-234m daughters. For convenience, this phenomenon will be referred to as 

the Putzier effect. As quoted by Putzier (1982): 

In the earlier years in handling large quantities of depleted uranium, and to some 

extent this is true in more recent years, we did have a significant beta radiation 

control problem in Building 444. This was not experienced so much in the 

machining areas but in the part of the foundry operations we called burnout and 

breakout. Castings were removed by breaking them out of the molds. This 

operation and the recovery of the material from the casting and handling the 

molds themselves resulted in very high beta radiation levels. There was an 

extremely high level of beta radiation associated with this because the first two 
White Paper – TBD-6000 Issue 1 3 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

daughters of 238U are beta emitters and during the molten state of the uranium 

there is a tendency for these two daughters to flow to the top and also to show up 

at the interface of the uranium and the mold itself thereby enhancing the amount 

of beta radiation coming off from the chunk of the material. We used to use as a 

rule of thumb that clean uranium metal in equilibrium with at least its first two 

daughters would give off on the order of 200 mrad per hour beta radiation at the 

surface of a piece of the metal. This went up by at least an order of magnitude 

and probably more than that. We can say that we saw readings as high as 2000 

to 3000 mrad/hr on castings of depleted uranium that were in the foundry area. 

Then, too, the dusts which were generated in the burnout and breakout process 

settled on various pieces of equipment and from that there were additional beta 

radiation fields generated. 

The phenomenon was not unique to Rocky Flats operations. Evidence of high surface 

concentrations of beta emitters has been observed on equipment used in uranium casting 

operations at Electro-Met and MCW (AEC 1949b, p. 51, 58; ORAUT 2005a). For example, at 

MCW, it was noted that (ORAUT 2005a, p. 86): 

Second, in the vacuum recasting of the uranium metal, impurities in the metal 

volatilized and condensed on the cooler portions of the furnace, creating spot 

deposits (AEC 1949b; Eisenbud 1975). The impurities contained Th-234 and 

Pa-234, which were concentrated to a significant degree in the deposits (AEC 

1949b; Eisenbud 1975); this deposit residue could have “up to 1000 times the 

beta activity of natural uranium” (AEC 1949b). Manual contact with these 

deposits during charging, discharging, cleaning, and repair of the furnaces 

provided “opportunity for hand irradiation of a greater magnitude than whole 

body” (AEC 1949b), possibly as much as 2–3 rads/week to exposed skin and 

perhaps to the eyes when the original ore was pitchblende at 25% average 

enrichment (Eisenbud 1975). Mallinckrodt (MCW 1949a) observed that 25% of 

Plant 4 workers received over 500 mrep/week beta and 3–6 workers per week 

received 2000 mrep or more; AEC (1949g) also observed that the beta values (on 

film badges) from Plant 4 consistently ranged up to 2.7 rep/week. 

Similarly, the authors of AEC 1949b state the following: 

A similar separation occurs in the processes at Mallinckrodt Chemical Works 

Plant 4 and Electro Metallurgical Company. In these plants, uranium metal, with 

UX1-UX2 in approximate equilibrium, is purified by vacuum recasting at a 

temperature which volatilizes various impurities in the metal, including the UX1-

UX2. These impurities condense on the cooler surfaces of the furnace interior and 

this deposit is the source of intense beta exposure during charging, discharging, 

cleaning and repair of the furnaces. 

Both of these later sources focus on build-up on equipment, rather than on the surface of uranium 

ingots. Some information on the surface distribution is found in U.S. Statutory Invention 
White Paper – TBD-6000 Issue 1 4 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

Registration H137, where it is noted that the highest β+γ readings were found on the bottom of 

the cylindrical casting, where initial solidification occurs. The readings taper off from the 

bottom to the top of the cylindrical surface, although not in a consistent manner. Radiation 

readings on the top surface of ingots generally tend to be higher than on upper portions of the 

cylindrical surface (Briggs et al. 1986). While there is broad evidence for the Putzier effect, the 

physical mechanisms that underlie the process have not been clearly articulated. 

For the Putzier effect to be observed on cast uranium ingots, one of two conditions must exist: 

• Either the Th-234 and Pa-234m are not removed from the uranium during refining of the 

ore to produce metal, allowing the Putzier effect to occur upon the initial vacuum casting 

of uranium metal 

• Or sufficient time has passed after a refining process (i.e., one which successfully 

removes thorium during the solvent extraction process) to allow in-growth of the shortlived progeny, and then, in subsequent melt-refining steps in the purification process, the 

Putzier effect occurs 

First, let us consider the question of whether or not Th-234 is removed during uranium ore 

refining. A simplified schematic diagram for uranium ore processing is presented in Figure 1. It 

should be noted that, after the ore is digested in nitric acid and treated to remove radium, the 

product liquor is fed to the solvent extraction process. In this process, the uranium containing 

aqueous product liquor is emulsified with a suitable organic solvent (e.g., ethyl ether or tributyl 

phosphate in kerosene) in the extraction column. The uranium partitions to the solvent phase and 

the impurities (such as Th and Pa) are concentrated in the aqueous phase. The immiscible phases 

are then separated and the aqueous (raffinate) phase with the impurities is treated as a waste 

stream. The uranium is then stripped from the organic phase and prepared for the next process 

step. Christofano and Harris (1960) state that, “the material remaining in the aqueous phase 

contains nitrates of all the undesirable metals including the UX1 and UX2 radioactive 

components.” However, Christofano and Harris (1960) do not provide any quantitative 

information on how effectively Th and Pa are removed from the uranium process stream. 

According to the Fernald TBD (ORAUT 2004, p. 71), “Uranium received at the FEMP usually 

has been through one or more chemical separations at other sites. The separations remove most 

of the daughter products.” Based on these sources, it is reasonable to assume that most, but not 

all, of the Th-234 and Pa-234m are removed during solvent extraction. 

The second necessary condition for the Putzier effect to be observed involves a positive answer 

to the question, If thorium is quantitatively separated from the uranium during solvent extraction, 

has sufficient time passed for significant in-growth of Th-234 to have occurred prior to casting of 

uranium ingots? Th-234 has a 24.1-day half-life, as compared to a 4.47E+09-year half-life for 

the U-238 parent. Thus, secular equilibrium of Th-234 and U-238 is rapidly approached. 

Figure 2 shows the build-up of Th-234 in uranium from which all thorium had initially been 

removed by chemical processing. Th-234 has reached 50% of its equilibrium value after 24 days 

and 90% after about 80 days. 
 

White Paper – TBD-6000 Issue 1 5 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

 

 

 

 

 Sampling 

 Digestion 

Radium Removal 

Solvent Extraction 

Denitrification 

Oxide Reduction 

UF4 Conversion 

UF6 Conversion U Metal Production 

U Recasting 

Nitric Acid 

Recovery 

Pitchblende Ore Concentrate

Nitric Acid 

Gangue 

RaSO4 

BaSO4 Cake 

Solvent to Recovery 

Raffinate to Disposal 

(Th-234 & Pa-234x) 

Hydrogen 

Anhydrous HF 

Mg Chips 

MgF2

H2SO4

BaCO3

 F2

 

 

Figure 1. Uranium Refining Flow Diagram 

(Based on Christofano and Harris 1960) 
Th-234 In-Growth

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

time after separation (yr)

relative concentration

Figure 2. In-Growth of Th-234 into Natural Uranium as a Function of Time 

after Initial Separation 

Assuming that Th-234 is quantitatively removed from uranium during solvent extraction, the 

question then becomes, what is the elapsed time between completion of solvent extraction and 

arrival of a uranium billet at a fabricator for rolling, forging, extrusion, etc.? At Atomic 

Weapons Employer (AWE) sites, many of the unit operations involved in uranium refining were 

not integrated, but instead were assigned to different facilities. Prior to the start-up of Fernald in 

late 1951, ore digestion, solvent extraction, denitration, and reduction to brown oxide (UO2) 

were performed at MCW in St. Louis, Missouri. The brown oxide was then shipped by rail to 

Linde in Tonawanda, New York. At Linde, the brown oxide was converted to green salt (UF4) 

and shipped by truck to Electro-Met in Niagara Falls, New York. At Electro-Met, the green salt 

was reduced to uranium metal and cast into billets in vacuum induction furnaces. The billets 

were then shipped by rail to locations such as Simonds Saw and Steel in Lockport, New York, or 

Vulcan Crucible Steel in Aliquippa, Pennsylvania, for rolling (AEC 1949b) for fabrication. 

Thus, the steps required to obtain cast uranium billets suitable for subsequent fabrication involve 

processing at three locations, one rail shipment, and one truck shipment. It is highly unlikely 

that this sequence of events could be accomplished in less than 1 month, by which time 

significant in-growth of uranium daughter would have occurred. Rail shipment to the metal 

fabricators would involve only decay of surface contamination, not in-growth. 

White Paper – TBD-6000 Issue 1 6 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

In the context of all metalworking operations examined in TBD-6000 other than scrap remelting, 

the Putzier effect would be an issue only for those operations where the contamination on the 

surface of the cast uranium billet was not removed prior to fabrication, or where sufficient time 

has elapsed after casting for Th-234 on the surface to experience significant radioactive decay. 

For example, Electro-Met shipped cast billets to Simonds Saw and Steel for rolling (AEC 

1949b). There is no evidence that Electro-Met machined the surfaces of the cast billets prior to 

shipment. Thus, contamination from Th-234 and Pa-243m on the cylindrical surfaces would not 

have been removed, and workers at Simonds handling the billets could have experienced 

abnormally high skin doses. However, power hacksaws were used to cut the billets to length at 

Electro-Met (Dust Sample Results, Nov. 1948–Jan. 1949). During this process, we presume that 
White Paper – TBD-6000 Issue 1 7 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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 top and perhaps the bottom of the cast billets were removed and scrapped;1

 thus, any 

excessive surface contamination in those areas would have been removed. If the metal-working 

operations occurred at least 30 days after casting, the Th-234 on the surface would have decayed 

to 42% of its initial value. 

In the case of scrap recovery, an even longer time would have passed between chemical 

separation and remelting of the scrap into ingots for refabrication. The resultant ingots would, in 

all probability, have high surface concentrations of Th-234 and Pa-234m. 

In conclusion, it is highly likely that any uranium handled at AWE facilities that worked uranium 

would have elevated surface concentrations of Th-234 and Pa-234m. Assumptions underlying 

this conclusion for metal-working operations other than scrap remelting include the following: 

• The surfaces of the uranium ingots are not removed by machining prior to shipment to 

the fabrication shop 

• The time between casting of the ingot and fabrication is less than 1 to 2 months 

Operators involved in scrap remelting would be highly likely to experience elevated doses from 

the short-lived uranium progeny. 

TBD-6000 Approach to Exposure/Dose Estimation 

 

The approach taken in TBD-6000 to estimate exposure to non-penetrating radiation from 

uranium surfaces is presented in Section 6.3 of that document. The key assumptions used in 

calculating operator dose are as follows: 

• Workers spend 50% of their time with their hands in contact with a uranium object 

• The calculated dose to the skin on the hands and arms from contact with an unshielded 

slab of uranium metal is 230 mrem/hr (Coleman et al. 1983) which, based on a 40-hr 

work week, is 630 mrem/calendar-day (0.5 × 230 mrem/hr × 8 hr/work-day × 250 workdays/365 calendar-days) 

• The photon dose 1 foot from a uranium slab is 2.08 mrem/hr (Anderson and Hertel 2005) 

1

 According to SRDB 8917 (Dust Sample Results, Dec. 1947-May 1948), the saw operator cut a sample 

from the end of the billet. 
White Paper – TBD-6000 Issue 1 8 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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 dose to the skin other than the hands and arms is estimated to be 10 times the photon 

dose at 1 foot (This factor is apparently based on a review of film badge data in 

“ORAUT 2005,” but we have been unable to trace this assumption to its source.)2

• The dose to the skin other than the hands and arms is 57 mrem/calendar-day based on a 

40-hour work-week (0.5 × 2.08 mrem/hr × 10 × 8 hr/work-day × 250 workdays/365 calendar-days) 

• The estimated non-penetrating doses are assumed to be geometric mean (GM) values 

with a geometric standard deviation (GSD) of 5 

From these data, it can be calculated that the annual exposures to the skin on the hands and arms 

is 230 rem/yr (230 mrem/hr × 0.5 relative contact time × 2,000 work-hours/yr) and to the skin on 

other parts of the body is 20.8 rem/yr. The equivalent 95th percentile values are 3,250 rem/yr and 

294 rem/yr, respectively. The same doses are assumed to be applicable to all uranium metalworking operations covered in TBD-6000, including extrusion, rolling, forging, slug production, 

machining, and scrap recovery (e.g., by remelting). 

 

The whole-body dose in Table 6.4 of TBD-6000 is based on the assumption that workers spend 

half of their time 1 foot from a rectangular uranium ingot. MCNP calculations by Anderson and 

Hertel (2005) result in a dose of 2.08 mrem/hr, which can be converted to a median annual dose 

of 2.08 rem/yr or a 95th percentile dose of 29.4 rem/yr. 

NIOSH Response 

In the Issue I White Paper, NIOSH describes how they used a very large database (HIS-20) 

consisting of 124,113 annual dose measurements taken at Fernald from 1952 through 2006 

(ORAUT 2007b).3 Work at Fernald covered more operations than were evaluated in TBD-6000 

and included other chemical compounds of uranium in addition to uranium metal. Operations at 

Fernald included uranium melting and casting that can result in increased dose from beta 

radiation. From this database, NIOSH obtained the maximum annual dose to an individual and 

compared that maximum dose to the 95th percentile dose based on Table 6.4 of TBD-6000. The 

comparison is duplicated below as Table 1. 

2

 According to the authors of TBD-6000, “For dose to other skin on the worker’s body that is not in direct 

contact with uranium metal, but is nearby (for example, a worker’s neck and face when the hands are in contact with 

metal), a dose relation can be used that estimates this dose to be 10 times the photon dose rate at 1-foot. This 

relation, based on a review of film badge data, is documented in (ORAUT, 2005).” The citation ORAUT 2005 

contains a typographical error that makes traceability of the source of the information difficult. The reference list in 

TBD-6000 cites five ORAUT 2005 references (ORAUT 2005a, b, c, d, and e). A check of references ORAUTa, b, c 

and d revealed that ORAUT-2005d (ORAUT-OTIB-0004) makes a similar statement to that quoted above from 

TBD-6000, but provides no basis for the statement. 3

 While ORAUT 2007b is not specific, we believe that the annual doses in that reference are the summed 

weekly doses. 
White Paper – TBD-6000 Issue 1 9 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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 1. Annual Dose in Rem - Skin Other than Hands and Arms 

Deep Shallow 

TBD-6000 – 95th 29.375 293.747 

Fernald – max 12.300 52.000 

From this comparison, it can be seen that the 95th percentile doses calculated from the GM and 

GSD values in Table 6.4 of TBD-6000 are more limiting than the maximum annual dose actually 

observed in a large population of film badge measurements at Fernald. Enhanced beta and 

gamma exposures from melting and casting of uranium are included in the population of Fernald 

doses from which the maximum value was selected. Since the number of samples collected at 

Fernald was about 124,000, it is clear that the 95th percentile for that population is subsumed by 

the recorded maximum. The approach to dose reconstruction developed in TBD-6000 can, in 

theory, yield more conservative results than those based on actual measurements at Fernald, 

which SC&A agrees likely included data from operations where Th-234 and Pa-234m were 

concentrated on uranium surfaces. It should be noted that this comparison applies to the skin 

other than the hands and arms. 

SC&A Comments on NIOSH Response 

Another analysis of the Fernald data is provided in ORAUT 2008 (ORAUT-OTIB-0073), which 

documents 50th percentile and 95th percentile annual coworker doses by year, adjusted for 

missing doses. The highest reported 95th percentile shallow dose was 9.591 rem for 1963.4

 As 

expected, this is well below the quoted maximum of 52 rem reported by NIOSH in its white 

paper. Similarly, the highest reported 95th percentile whole-body dose was 1.769 rem, also for 

1963, as compared to a maximum observed deep dose of 12.3 rem. SC&A agrees that the 

maximum penetrating and non-penetrating doses reported for Fernald workers are substantially 

higher than the upper 95th percentile of the penetrating and non-penetrating doses observed at 

Fernald. We also agree that the upper 95th percentile doses provided in TBD-6000 are even 

higher than the highest penetrating and non-penetrating doses observed at Fernald. Hence, it 

certainly appears that the upper end of the distribution of the external doses adopted for use in 

TBD-6000 includes the annual doses to workers that might have experienced the Putzier effect at 

Fernald. 

To broaden the comparison, SC&A examined the external exposure data from the Electro-Met 

for the period from June 7, 1948, through September 26, 1949 (Dosimetry Results, March 1948 

through Jan. 1949, and Dosimetry Results, Jan.–Sep. 1949). Electro-Met cast uranium ingots 

from remelted uranium derbies and scrap. During this period, about 2,000 weekly film badge 

measurements were made. The highest annual beta dose was to a [job category redacted] who 

received a dose of 17 rem.5

 This value is below the median value of 20.8 rem, based on 

Table 6.4 of TBD-6000. 

 4

 Table 7-1 of ORAUT-OTIB-0073 states that the unit of measure is rem. However, David Allen of 

CDC/NIOSH/OD confirmed in an e-mail dated December 11, 2009, that this was a typographical error and the units 

should have been reported as mrem. The values cited in the text here have been corrected accordingly. 5

 This is based on the sum of 59 weekly measurements made from [redacted], 1948, through [redacted], 

1949, annualized based on a 50-workweek year. 
White Paper – TBD-6000 Issue 1 10 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

 

As noted above in the Background section, the beta values (on film badges) from Plant 4 at 

MCW6

 ranged up to 2.7 rep/week. However, it is likely that the weekly exposure of 2.7 rep was 

not experienced for 50 weeks per year. In support of this assertion, we note in ORAUT 2007a 

(p. 84) that while two beta exposures at Plant 4 during the period November 1, 1948 through 

January 24, 1949, were above 1,500 mrep/week, 65% of the weekly measurements were less 

than 300 mrep/week. From this information, we can make a rough approximation of the 

maximum annual skin dose – 50 × (2700 × 0.04 + 1500 × 0.31 + 300 × 0.65) = 38.4 rep/yr. 

The discussion to this point has focused on the dose to the skin other than the hands and arms. 

The hands and arms dose adopted in TBD-6000 is 630 mrem/calendar-day, or a GM of 

230 rem/yr (95th percentile – 3,250 rem/yr). Unlike the shallow dose to the hands and arms, 

which is based on experimental measurements from a uranium metal source with the radiation 

attenuated through mylar films, the dose to the skin other than the hands and arms dose is based 

on MCNP calculations of the photon dose (at 1 foot) from a large uranium metal source and an 

assumed correlation between photon dose and skin dose derived from film badge studies. We 

presume that the experimental studies of Coleman et al. (1983) to measure contact doses used 

uranium samples in which Th-234 and Pa-234m were uniformly distributed throughout the metal 

mass. Thus, the laboratory measurements would not reflect elevated surface concentrations of 

the U-238 progeny. While it can be argued that film badge data from Fernald conservatively 

reflect doses to some areas of the skin, such as the face and neck, care must be taken in 

extending the argument to doses to the hands and arms, since the dose determined from a film 

badge suspended from a lapel may not adequately reflect the dose to the hands in direct contact 

with a radiation source. 

NIOSH described modeling results in OCAS 2005 (OCAS-TIB-0013), which developed 

correlations between film badge exposures and exposures to other body parts. They determined 

that the hands-to-badge ratio was to 3.65. If one applies this factor to the maximum observed 

shallow dose at Fernald of 52 rem/yr (see Table 1), the maximum estimated exposure to the 

hands would be 190 rem/yr. This is below the median value of 230 rem/yr for the hands and 

arms developed in Table 6.4 of TBD-6000, indicating that values in that table are sufficiently 

conservative to account for doses to the hands and arms from high surface concentrations of 

short-lived U-238 progeny. 

SC&A concurs with NIOSH that the approach used to develop data for Table 6.4 of TBD-6000 

captures exposures from elevated surface concentrations associated with high concentrations of 

beta-emitting radionuclides. However, SC&A had concerns that the data in TBD-6000 can be 

used in dose reconstruction in ways that may not be bounding. TBD-6000 does not prescribe 

how the data are to be used; it only presents the GM and GSD for default external doses to 

penetrating and non-penetrating radiation. During the Work Group meeting on December 16, 

2009, NIOSH explained that since the upper 95th percentile values for external exposures in 

TBD-6000 include doses that might be associated with the Putzier effect, they plan to simply 

assign the full distribution to any unmonitored workers, whether or not they experienced the 

Putzier effect. SC&A expressed concern that if there is a reasonable possibility that a given 

unmonitored worker at an AWE facility had job responsibilities that included regularly working 

6

 Uranium casting was done in Plant 4. 
White Paper – TBD-6000 Issue 1 11 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

with ingots, this approach could underestimate their annual exposure to both penetrating and 

non-penetrating radiation. 

We recognize that this concern is perhaps broader than the scope of the question considered in 

the Issue 1 White Paper; however, we believe that it needs to be explicitly addressed in TBD6000. Table 2 compares several possible metrics based on TBD-6000 for characterizing the 

shallow dose exposure with various field studies. 

Table 2. Comparison of Various Measures of Skin Dose 

Metric for Calculating Shallow Dose Annual Dose to Hands 

and Arms (rem) 

Annual Dose to Skin ex. 

Hands and Arms (rem) 

TBD-6000 95th percentile 3,250 294 

TBD-6000 arithmetic mean 840 76.0 

TBD-6000 median 230 20.8 

Fernald maximum 190a 52 

Fernald 95th percentile of highest annual doses (1963) 35.0 a 9.59 

MCW maximum 140a 38.4 

Electro-Met maximum 62 a 17 

Theoretical maximum 3000b

a – Annual dose to the skin other than hands and arms multiplied by factor of 3.65. b – This is the theoretical maximum dose to skin of the hands and arms of a worker if he spends 1,000 hr/yr 

handling ingots that have experienced the Putzier effect (i.e., 200 mrem/hr × 15 × 1,000 hrs/yr = 3,000,000 mrem/yr 

or 3,000 rem/yr). This value is provided solely for comparison to the other values in the table. We are not 

suggesting that such exposures are plausible. 

 

Considering first the skin dose other than the hands and arms, it can be seen from Table 2 that 

the TBD-6000 median of 20.8 rem/yr is a factor of 2 higher than the highest annual 95th

percentile of the Fernald doses (9.59 rem/yr for 1963), but is lower than the maximum observed 

dose at Fernald of 52 rem. We believe that this may be the result of a conservative assumption 

regarding the fraction of time spent in close proximity to uranium objects (i.e., 50%). Based on 

more limited data, the maximum doses at Electro-Met and MCW are lower than those at Fernald 

by 26% and 67%, respectively. 

While use of the TBD-6000 median for the annual dose to the skin other than the hands and arms 

generally appears to be claimant favorable, it is not clear whether use of the TBD-6000 median 

of 20.8 rem/yr is always claimant favorable when tested against the various measures 

summarized in Table 2. Clearly, the median is less than the Fernald maximum. However, all of 

the measures are less than the TBD-6000 95th percentile. The question of whether a stochastic 

distribution based on the GM/GSD of 20.8/5 rem is more or less claimant favorable than the use 

of a deterministic value set at the 95th percentile of distribution (294 rem) is addressed in the next 

section. 

Turning to the hands and arms, as shown in Table 2, the median dose in TBD-6000 is 

230 rem/yr, which is higher than the estimated Fernald maximum of 190 rem/yr. The TBD-6000 

95th percentile dose of 3,250 rem/yr is about the same as the theoretical maximum dose 

(3,000 rem/yr), as described in footnote b of Table 2. Hence, we believe using the full 
White Paper – TBD-6000 Issue 1 12 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

distribution in TBD-6000 for surface exposures to the hands and arms is claimant favorable and 

takes into account the possibility of the Putzier effect. 

A similar analysis was made for total body dose. The maximum observed weekly gamma 

exposure at Electro-Met was 690 mr. The annual dose for the [job category redacted] who 

received this high weekly dose was 3.3 R, which is about 27% of the Fernald maximum of 12.3 

rem reported in Table 1.7

 

Table 3 presents a comparison of various measures of penetrating doses. As indicated, the 

median value in TBD-6000 is about 1/15th the maximum theoretical value and is comparable to 

the highest observed annual 95th percentile value at Fernald. However, it lies well below the 

Fernald maximum of 12.3 rem. 

Table 3. Comparison of Various Measures for Estimating Whole-Body Dose 

Metric for Calculating Deep Dose Annual Whole Body Dose (rem) 

TBD-6000 95th percentile 29.375 

TBD-6000 arithmetic mean 7.60 

TBD-6000 median 2.08 

Fernald maximum 12.300 

Fernald 95th percentile of highest annual doses (1963) 1.769 

Electro-Met maximum 3.3 

Theoretical maximum 30a

a. This is the theoretical maximum penetrating dose a worker might experience if he spends 1,000 hours 

per year 1 foot from ingots that have experienced the Putzier effect (i.e., 2 mrem/hr × 15 × 1,000 hrs/yr = 

30,000 mrem/yr or 30 rem/yr. This value is provided solely for comparison to the other values in the 

table. We are not suggesting that such exposures are plausible. 

Appropriate Metric to be Used in Dose Reconstruction 

As described in Table 1, NIOSH compared the maximum annual external doses observed at 

Fernald with the 95th percentile doses from TBD-6000. The comparison showed that the 

observed maximum annual doses were lower than the 95th percentile doses in TBD-6000. 

Consequently, use of the 95th percentile doses appeared to be claimant favorable. However, it is 

implicit in the TBD-6000 guidance that the dose reconstructor should use the full distribution 

based on the GM and GSD to estimate doses. At the December 16, 2009, Work Group meeting, 

NIOSH expressed the opinion that use of the GM/GSD approach could be more conservative 

than use of the 95th percentile (or some other deterministic metric) in determining probability of 

causation (POC) of a radiation-related cancer. A worker is entitled to compensation under 

EEOICPA if there is a 50% or greater probability at the upper 99% confidence interval that his 

exposure to radiation while working on atomic weapons caused his cancer (42 CFR 81). 

Because the POC uses the 99% upper confidence interval to assess whether the 50% probability 

threshold is attained, NIOSH believed that the stochastic approach with a high GSD could be 

more conservative. SC&A was not convinced. The Work Group requested that SC&A make 

 7

 For purposes of this report, we assume that exposure to 1 R of gamma radiation results in a dose 

equivalent of 1 rem. 
White Paper – TBD-6000 Issue 1 13 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

some hypothetical POC calculations to clarify which approach produced the most claimantfavorable results. 

SC&A used IREP to compare POCs for shallow dose and whole-body dose. Assumptions used 

for the shallow dose calculations included the following: 

• Annual dose: stochastic with GM – 20.8 rem/GSD – 5 or deterministic with 95th

percentile – 294 rem 

• Exposure duration – 1 year (1944) 

• White, non-Hispanic male born 1914 

• Basal cell cancer diagnosed in 1970 

The POC based on the GM/GSD was 82.61%, while the POC based on the 95th percentile was at 

89.06%. While the 95th percentile dose resulted in a slightly higher POC than that for GM/GSD, 

the differences are not relevant, because in either case, the POC is substantially above the 50% 

probability required for compensation. 

A similar comparison was made for whole-body dose based on the following assumptions: 

• Annual dose: stochastic with GM – 2.08 rem/GSD – 5 or deterministic with 95th

percentile – 29.375 rem 

• Exposure duration – 1 year (1944) 

• Photon energy: 30–250 keV 

• White, non-smoking male born 1914 

• Lung cancer diagnosed in 1970 

The POC based on the GM/GSD was 48.56%, while the POC based on the 95th percentile dose 

was at 64.4%. In this hypothetical example, the claimant would not have been compensated 

based on the full distribution, but would have been compensated if the 95th percentile had been 

used. 

Conclusion 

SC&A concurs with the NIOSH position that the Putzier effect can be adequately bounded by 

the guidance provided in TBD-6000. Although the Putzier effect was not specifically considered 

in TBD-6000, the assumptions used in that document to develop dose reconstruction parameters 

for shallow dose (both to the hands and arms, and skin, other) and deep dose are sufficiently 

conservative to accommodate situations where high surface concentrations are present. This 

conclusion is specific to sites where uranium ingots were fabricated. Based on actual site 

measurements, use of the GM and the full distribution should be claimant favorable for those 

sites. 
White Paper – TBD-6000 Issue 1 14 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

This conclusion should not be construed as blanket acceptance of the concept that the use of the 

full distribution is sufficiently claimant favorable under all circumstances. As shown by the 

hypothetical POC calculations presented here, use of the full distribution may not be bounding 

when compared with use of the 95th percentile. 

Note on TBD-6001 

As stated above, this report focuses on TBD-6000. The methodology for determining photon 

doses relies on MCNP calculations for operators who spend half their time standing near a large 

uranium slab. Shallow doses to the hands and arms are based on experimental measurements, 

coupled with the assumption that the operator’s hands are in contact with a uranium object for 

half of the time. Shallow doses to the skin other than the hands and arms are based on the 

calculated photon dose at 1 foot and the observation from film badge studies that the surface 

dose is about 10 times the photon dose at 1 foot. 

In TBD-6001, on the other hand, dose rates were often obtained from measurements at various 

work sites (see Table 7.1 of that document). For example, worker exposures from the uranium 

recasting process were based on measurements made at MCW (ORAUT 2005a). These processspecific dose rates are converted to daily worker dose rates in Table 7.3. Table 4 below 

compares daily dose rates from TBD-6000 and TBD-6001. The comparison is for operators 

working 40 hours per week. In each case, the values are the GM with an assumed GSD of 5. 

The doses are mrem/calendar-day except for the TBD-6001 whole-body dose, which is in units 

of mR/calendar-day. 

Table 4. Comparison of External Dose Rates for Similar Operations Based on TBD-6000 

and TBD-6001 (mrem/calendar-day) 

Source Operation Whole-Body Dose Hands & Arms Dose 

(non-penetrating) 

Other Skin Dose 

(non-penetrating) 

TBD-6000, Table 6.4 Scrap Recovery 5.70 630 57 

TBD-6001, Table 7.3 Recasting 816 (mr/calendar-day) 30.3 842 

From this table, it is clear that use of the two guidance documents provides very dissimilar 

results when addressing operations where the Putzier effect is involved. Detailed reconciliation 

of the differences is beyond the scope of this analysis. In its review of TBD-6001, SC&A 

expressed concerns about the lack of transparency in NIOSH’s development of Table 7.3 

summarizing external occupational doses (SC&A 2008). 

References 

42 CFR 81, 2002. Guidelines for Determining the Probability of Causation Under the Energy 

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

Register/Vol. 67, No. 85/Thursday, p 22,296; May 2, 2002; SRDB Ref ID: 19391. 

AEC (Atomic Energy Commission) 1949b. Health Hazards in NYOO Facilities Producing and 

Processing Uranium. Report by the New York Operations Office Medical Division. April 18, 

1949.
White Paper – TBD-6000 Issue 1 15 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

AEC (Atomic Energy Commission) 1949g. No subject. Letter to K.J. Caplan of Mallinckrodt 

Chemical Works from A.R. Piccot of AEC. June 29, 1949. 

Anderson, J.L. and N.E. Hertel, 2005. Bremsstrahlung Doses from Natural Uranium Ingots. 

Radiation Protection Dosimetry, Vol. 115, No. 1–4, pp. 298–301. 

Battelle-TBD-6000. Site Profiles for Atomic Weapons Employers that Worked Uranium and 

Thorium Metals. Rev. F0. Battelle Team. Effective date: December 13, 2006. 

Battelle-TBD-6001. Site Profiles for Atomic Weapons Employers that Refined Uranium and 

Thorium Metals. Rev. F0. Battelle Team. Effective date: December 12, 2006. 

Briggs, G.G., T.R. Kato, and E. Schoenegg, 1986. Process for Reducing Beta Activity in 

Uranium. United States Statutory Invention Registration, Reg. Number H137. October 7, 1986. 

Christofano E. and W.B. Harris, 1960. The Industrial Hygiene of Uranium Refining. Env Health

1(5):74-96. 

Coleman, R. L., Hudson, C. G., and Plato, P. A., 1983. “Depth-dose curves for 90Sr and natural 

and depleted uranium in mylar,” Health Physics, 44(4): 395-402. SRDB Ref. ID: 12288. 

Dosimetry Results, March 1948–Jan. 1949. Dosimetry Results for Electro-Metallurgical 

Employees from March 15, 1948 through January 24, 1949. SRDB Ref ID: 11547. 

Dosimetry Results, Jan.–Sep. 1949. Dosimetry Results for Electro-Metallurgical Employees 

from January 3, 1949 through September 26, 1949; SRDB Ref ID: 11548. 

Dust Sample Results, Nov. 1948–Jan. 1949. Dust Sample Results from November 3, 1948 

through January 12, 1949, includes Job Analysis Sheets; SRDB Ref ID: 8912. 

Dust Sample Results, Dec. 1947–May 1948. Dust Hazard Reports with Dust Sample Results for 

December 24, 1947, March 30, 1948, and May 14, 1948; SRDB Ref ID: 8917. 

Eisenbud M., 1975. “Early Occupational Exposure Experience with Uranium Processing.” In: 

Occupational Health Experience with Uranium, Proceedings of a United States Atomic Energy 

Commission conference. Arlington, Virginia. ERDA-93; 1975: 9-24. 

MCW (Mallinckrodt Chemical Works) 1949a. Beta Radiation – Metal Plant. Letter to B.S. 

Wolf of AEC from H.E. Thayer of Mallinckrodt Chemical Works. February 9, 1949. 

ORAUT (Oak Ridge Associated Universities Team) 2004. Technical Basis Document for the 

Fernald Environmental Management Project (FEMP) – Site Description, Rev. 00, ORAUTTKBS-0017-2. Effective Date May 20, 2004. 
White Paper – TBD-6000 Issue 1 16 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

OCAS (NIOSH Office of Compensation and Support) 2005. Special External Dose 

Reconstruction Considerations for Mallinckrodt Workers, OCAS-TIB-0013, Rev. 0. National 

Institute for Occupational Safety and Health. Effective Date: November 26, 2005. 

ORAUT (Oak Ridge Associated Universities Team) 2005a. Basis for Development of an 

Exposure Matrix for the Mallinckrodt Chemical Company St. Louis Downtown Site and the St 

Louis Airport Site, St. Louis, Missouri, Period of Operation: 1942–1958. ORAUT-TKBS-0005, 

Rev. 01. Effective Date: March 10, 2005. 

ORAUT (Oak Ridge Associated Universities Team) 2005d. Estimating the Maximum Plausible 

Dose to Workers at Atomic Weapons Employer Facilities, ORAUT-OTIB-0004. Rev. 03 PC-2. 

Effective Date: August 12, 2005. 

ORAUT (Oak Ridge Associated Universities Team) 2007a. Basis for Development of an 

Exposure Matrix for the Mallinckrodt Chemical Company St Louis Downtown Site and St. Louis 

Airport Site, St Louis, Missouri, ORAUT-TKBS-0005, Rev. 02. Effective Date: June 14, 2007. 

ORAUT (Oak Ridge Associated Universities Team) 2007b. Fernald HIS-20 Health Physics 

database export; Microsoft Access database format; provided to ORAUT 2007. Available at: 

Abrwh on ‘Sqp-cinc-ocas\Ocas’ O:\AB Document Review\Fernald. 

 

ORAUT (Oak Ridge Associated Universities Team) 2008. External Coworker Dosimetry Data 

for the Fernald Environmental Management Project, ORAUT-OTIB-0073, Rev. 00. September 

22, 2008. 

Putzier, E.A., 1982. The Past Thirty Years at Rocky Flats Plant, Rocky Flats Plant, Golden, 

Colorado. November 1982. 

SC&A 2007. Draft Review of Battelle-TBD-6000, Site Profiles for Atomic Weapons Employers 

that Worked Uranium and Thorium Metals. Contract No. 200-2004-03805, Task Order No. 3. 

SC&A, Inc., Vienna, Virginia, and Saliant, Inc., Jefferson, Maryland. 

SC&A 2008. Draft Review of Battelle-TBD-6001, Site Profiles for Atomic Weapons Employers 

that Refined Uranium and Thorium Metals, Revision FO dated December 13, 2006. Contract 

No. 200-2004-03805, Task Order No. 1, SCA-TR-TASK1-0026. SC&A, Inc., Vienna, Virginia, 

and Saliant, Inc., Jefferson, Maryland. February 2008. 
White Paper – TBD-6000 Issue 1 17 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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 A 

BATTELLE-TBD-6000 ISSUE 1 WHITE PAPER 

Consideration of Recasting Increasing Progeny Concentration 

Prepared by Dave Allen, OCAS 

December 10, 2009 

Background 

Issue 1 of the SC&A review of TBD-6000 indicated that the TBD would benefit from a 

discussion of the possibility that recasting of uranium metal raises the concentration of Th-234 

and Pa-234m close to the surface of the ingots. SC&A referred to Putzier in describing this 

phenomenon. NIOSH responded in agreement that the TBD would benefit from the discussion. 

During the October 14, 2009 meeting of the Working Group, it was clarified that SC&A felt the 

issue was more than simply adding a discussion to the TBD. SC&A felt the phenomenon could 

cause shallow doses in TBD-6000 to be as much as a factor of ten higher. This white paper 

explores this issue by comparing the TBD-6000 values with the shallow dose at another facility 

that recast uranium. 

TBD-6000 

TBD-6000 provides deep and shallow dose rates for various uranium metal production tasks. 

The values are provided in Table 6.4 which indicates a deep dose rate of 5.7 mrem per calendar 

day and a shallow dose rate of 57 mrem per calendar day for a 2000 hour work year. These dose 

rates are the geometric mean of a lognormal distribution that has a geometric standard deviation 

of five. 

Fernald Data

Dosimeter data from the Fernald plant will be used for the comparison in this white paper. 

Fernald performed various tasks with several chemical forms of uranium. One of those tasks 

involved re-melting uranium metal and casting it into molds. The data set consists of annual 

doses from each employee between 1952 and 2006. A total of 124,113 individual annual doses 

were reviewed. 

Analysis 

Since the Fernald data includes operations other than recasting, a distribution of the shallow dose 

could be reduced by these other operations. Therefore, the maximum doses were compared to 

the 95th percentile of the TBD-6000 distribution. 

The results of these analyses are shown in the Table. The TBD-6000 doses were converted to 

annual doses. Both the maximum deep and the maximum shallow dose at Fernald are provided in 

the Table. These represent the maximum from any employee for any year. They are not from 

the same employee or the same year. 

Annual Dose in Rem 

Deep Shallow 

TBD-6000 – 95th 29.375 293.747

Fernald – max 12.300 52.000
White Paper – TBD-6000 Issue 1 18 SC&A – December 30, 2009 

NOTICE: This report has been reviewed for Privacy Act information, redacted accordingly, and 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. 

Conclusion 

The TBD-6000 doses at the 95th percentile exceed the maximum doses recorded at Fernald. 

While the phenomenon of increased shallow dose rates in recasting areas is well known, it 

appears other favorable assumptions in TBD-6000 account for this. 

Reference

Putzier, E. A. 1982. “The Past 30 Years at Rocky Flats: A Summary of Experiences and 

Observations at Rocky Flats Plant Over the Past 30 Years with Emphasis on Health and Safety.” 
Updated TBD-6000 Issues Matrix A8 SC&A – October 7, 2010

NOTICE: This October 7, 2010, version of the TBD-6000 Issues Matrix has been reviewed for Privacy Actprotected information (see Privacy Act 5 U.S.C. § 552a) and cleared for distribution to all interested parties. Future 

versions of this document will need to be reviewed before being cleared for Privacy Act-protected information.

ATTACHMENT 8: NIOSH WHITE PAPER ON THE PUTZIER EFFECT 

The report attached here, White Paper: TBD-6000 Working Group – Putzier Effect, dated 

September 2010, has been reviewed for Privacy Act-protected information and is cleared for 

distribution to all interested parties. 
White Paper

TBD‐6000 Working Group ‐ Putzier Effect

David Allen September 2010

During the May 12th 2010 meeting of the TBD‐6000 working group, NIOSH agreed to draft language

describing the “Putzier Effect” and provide that language to the working group. The language is

intended for incorporation into TBD‐6000. The language is presented here. The references included

here will be added to the reference section of TBD‐6000.

The language indicates in part a review of beta to gamma ratios at several plants. The table below

supports this review. It is based on dose values contained in an SC&A document titled “Review of NIOSH

Issue 1 White Paper Dated December 10, 2009” (SC&A 2009). The ratios were calculated and added

here. The hands to whole body ratio is not used in TBD‐6000 but it is instructive to review these as well.

Whole body

dose from

Table 3 (rem)

Skin dose

from Table 2

(rem)

Dose to the

Hands and

Arms from

Table 2

(rem)

Skin to

Whole

body ratio

Hands to

Whole body

ratio

TBD‐6000 95th percentile 29.375 294 3250 10.01 110.64

TBD‐6000 95th arithmetic

mean 7.6 76 840 10.00 110.53

TBD‐6000 95th median 2.08 20.8 230 10.00 110.58

Fernald maximum 12.3 52 190 4.23 15.45

Fernald 95th percentile of

highest annual doses (1963) 1.769 9.59 35 5.42 19.79

MCW maximum 38.4 140

Electro‐Met maximum 3.3 17 62 5.15 18.79

Theoretical maximum 30 3000 100.00

Proposed Language for TBD‐6000

When uranium metal is melted, impurities can separate from the metal matrix. Differences in densities

and melting points can then cause impurities to separate from the molten uranium metal and

This is a working document prepared by NIOSH or its contractor for use in discussions with the ABRWH or its

Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH

or ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This

document represents preliminary positions taken on technical issues prepared by NIOSH or its contractor.

NOTICE: This report 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.

1
concentrate on the surfaces. The two processes that routinely involve molten uranium metal are the

metal reduction process and the remelting process.

The metal reduction process involves mixing uranium tetrafluoride (UF4) with magnesium chips and

loading the mixture into a lined reduction vessel. The sealed vessel is heated to initiate the exothermic

reaction. The reaction results in the formation of magnesium fluoride (MgF2) and free uranium metal.

The temperature inside the vessel exceeds the melting point of uranium and, due to the high specific

gravity, the uranium collects in the bottom of the vessel forming a “derby”. The MgF2 is collected above

the derby as a slag. After it cooled, the derby is “broken out” of the vessel. The MgF2 slag had to be

broken and chipped away to dislodge it from the derby (Chrisofano 1960).

The derby resulting from the reduction step contained impurities that made it unsuitable for reactor

fuel. The metal was both purified and altered in shape in the remelt process. In this process, the

derbies are melted in a vacuum furnace and molten uranium metal poured into a graphite mold

(Chrisofano 1960). The vacuum casting removes volatile contaminants and allows other impurities to

float to the surface concentrating impurities near the top. Impurities can also be concentrated where

the molten uranium metal cools rapidly preventing (or minimizing) the time necessary for the impurities

to separate. This can cause impurities to also concentrate near other surfaces of the casting. The

separation can be improved by controlling the cooling of the cast uranium. If the mold is insulated near

the top, a steep temperature gradient is formed causing the ingot to solidify from the bottom to the top.

This allows impurities to separate and migrate to the top of the ingot without being trapped in

solidifying metal. The “hot‐top” that is formed is then cut off (cropped) to eliminate the impurities

(Fleishman‐Hillard 1967).

A third process worth mentioning is the dingot (direct ingot) process developed at Mallinckrodt. That

process produced a finish ingot directly in the metal reduction step. This eliminated the remelting step

by increasing the size of the metal reduction vessel and carefully controlling the temperature and

ingredients. After separation, the dingot was “scalped” by machining all the surfaces (Fleishman‐Hillard

1967).

Some of the impurities in the uranium include Th‐234 and Pa‐234m, decay products of U‐238 (as well as

residual magnesium, some slag, hydrogen, and others). These isotopes are beta emitters with relatively

short half‐lives. The process then causes a high concentration of these beta emitters in the top and

other surfaces of the cast ingot. This concentration can produce higher than normal beta dose rates

that then decay to a normal dose rate with a half‐life of 24.1 days.

This is a working document prepared by NIOSH or its contractor for use in discussions with the ABRWH or its

Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH

or ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This

document represents preliminary positions taken on technical issues prepared by NIOSH or its contractor.

NOTICE: This report 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.

2
The concentrating of decay products during the reduction process does not appear to occur. When the

uranium metal is first formed in the reduction process, it exists as molten droplets of uranium

intermixed with MgF2, and unreacted UF4 and magnesium. These droplets of molten uranium settle to

the bottom of the reduction vessel. The droplets are small enough that no appreciable separation can

occur within the drop. Separation would be possible once the metal collects in the bottom of the vessel.

There is some indication that these decay products are actually collected by the MgF2 before the derby is

formed resulting in a decrease in beta radiation levels on the derby (Briggs 1986). Even if separation

were to occur in the derby, the solidified MgF2 has to be broken or chipped away from the derby

(Chrisofano 1960). This likely would remove appreciable amounts of any material concentrated in the

surface layer.

The concentrated beta emitters near the surface of castings cause elevated beta radiation levels from

the uranium casting with little effect on gamma dose rates. This can cause beta to gamma dose rate

ratios to be significantly higher than uranium metal in equilibrium with its decay products. This elevated

ratio may not be limited to facilities where recasting of uranium metal is performed. Several months are

required to the beta radiation levels decrease to normal levels and castings could be shipped to other

sites in that time. Film badge readings at various sites indicate those sites engaged in remelting exhibit

the highest ratio. The ratio for those sites can approach 10. Therefore, a ratio of 10 is used in this

document to account for this affect.

References

Briggs, G.G., T.R. Kato, and E. Schoeneff, 1986. Process for Reducing Beta Activity in Uranium. United

States Statutory Invention registration, Reg. Number H137. October 7, 1986.

Christofano E. and W. B. Harris, 1960, The Industrial Hygiene of Uranium Refining. Env Health 1(5):75‐96.

Fleishman‐Hillard, 1967, Fuel For the Atomic Age, Completion Report on St. Louis‐Area uranium

Processing Operations, 1942‐1967. September 30, 1967.

SC&A (Sanford Cohen & Associates) 2009, Review of NIOSH Issue 1 White Paper Dated December 10,

2009, December 2009

This is a working document prepared by NIOSH or its contractor for use in discussions with the ABRWH or its

Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH

or ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This

document represents preliminary positions taken on technical issues prepared by NIOSH or its contractor.

NOTICE: This report 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.

3