Review of Parameters Associated with Defining Sufficient Accuracy
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January 2013
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L. Rutherford, NIOSH/DCAS
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One of the recommendations from the ten year review was to develop criteria or provide further guidance to 

determine if the information available for a site allows for the completion of sufficiently accurate dose 

reconstructions. After discussion with the Advisory Board’s SEC Issues work group, DCAS decided that an 

effective way to accomplish this was to review the criteria in the HHS Secretary’s decision letter to determine if 

a pattern could be identified. 

It was decided to initially look at the past year of determinations/designations, as these more recent decisions 

were likely to be more indicative of any common principles or practices that have emerged over time. DCAS 

reviewed these Secretarial designations and determinations to determine what factors led to the decision to 

either recommend or deny an SEC class. From this review a matrix (attached) was developed that identified the 

class evaluated and summarized the specific reasons for recommending adding or denying a class. Once the 

findings were summarized for each determination/designation, they were grouped based on their similarities.. 

As DCAS reviewed the matrix and summary of each determination/designation, it became clear it was not 

possible to identify specific circumstances or exposure types (e.g., thorium exposure) that would automatically 

lead to an infeasibility determination. Further, defining the amount of data necessary to determine feasibility 

was not possible. This is due to the fact that there are many interrelated factors that affect the feasibility 

determination. However, using the hierarchy of data for dose reconstruction as a guideline, it is possible to 

identify the typical data shortcomings that lead to an infeasibility determination and a general idea for what is 

necessary to determine feasibility. For example: 

Personal Monitoring Data 

1) To be representative, it must be possible to demonstrate that the highest exposed workers were 

monitored. This can be done by showing that most of the exposed work force was monitored (e.g., 

uranium at Weldon Spring) or that a large portion of a smaller potentially exposed group was monitored 

(Mound research quantity isotopes) and that the monitored group included the workers expected to 

receive the highest exposure. 

2) The monitoring method must allow for either directly or indirectly measuring the exposure potential 

(i.e. uranium bioassay for uranium exposures). For analyses not directly connected to the nuclide (such 

as gross alpha), additional analyses must also provide a method of sorting out different exposures 

without the method resulting in “implausibly high” intake values for some isotopes. For example, gross 

alpha measurements in urine that were primarily caused by uranium intakes could not be assumed to be 

the result of thorium exposure if the resulting calculations produced unrealistically high thorium 

estimates. 

Area Air Monitoring Data 

1) Area air monitoring information has a number of obstacles to overcome to demonstrate that it is 

representative of workplace exposures. Not only do they have to represent the breathing zone during 

operations, but it also is necessary to understand which workers were exposed and for how long. This is 

often done in a bounding fashion by assuming all workers were in the highest area 100% of the time. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Review of Parameters Associated with Defining Sufficient Accuracy
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That can, however, lead to unrealistically high intake estimates. An example would be the decision 

made at Linde Ceramics that office workers’ exposures could not be reconstructed by assuming 

continuous exposure to the high level air sample levels associated with decommissioning and 

decontamination activities. 

Source Term Data 

1) Source term data can take many forms depending on its use. It can be used to justify the use of 

surrogate data or to create a model. 

Model 

a.	­ Like area monitoring data, models must overcome the problem of producing unrealistically high 

estimates. The reason that models often provide unrealistic estimates is the tendency to 

conservatively estimate every parameter. By including conservatively high estimates of parameters 

such as building ventilation rate or respirable particle fractions models can easily produce 

implausibly high exposure estimates. 

b.	­ Besides the source term data necessary for a model, a number of assumptions are usually necessary 

and each of them have to have an adequate basis to be scientifically defensible. 

Surrogate Data 

c.	­ In order to justify the use of surrogate data the source term data is necessary. Also, the operations, 

engineering and administrative controls, material quantities must be similar. Again bounding data 

may be applied at times but this can cause unrealistically high values. 

With the above criteria in mind, the SEC decisions in the attached table can categorized as follows: 

Dose Reconstruction Feasible 

Adequate Personnel Monitoring Data 

1.	­ Mound SEC 0090 (Denial) – highest exposed workers monitored, employees with potential for 

exposure to research quantities were monitored for those isotopes. 

2.	­ United Nuclear SEC 0116 (uranium) – bioassay adequate even with 2 year gap {see area monitoring 

for thorium} 

Inadequate Personnel data but adequate area data 

1.	­ United Nuclear SEC 0116 (thorium) – area monitoring shown to cover entire area and time frame. 

Possible because of limited area and limited time frame 

2.	­ Titanium Alloys Manufacturing SEC 0190 – Work defined to a limited time and area well enough 

that small amount of area monitoring deemed adequate 

Inadequate personnel or area data but adequate source term data for modeling 

1.	­ Hangar 481 SEC 0139– enough source term data to show no internal exposure potential 

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Review of Parameters Associated with Defining Sufficient Accuracy
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Inadequate personnel or area data but adequate source term data for surrogate data use 

1.	­ Hooker (not in the attachment matrix) – enough source term data about the material to show 

surrogate data was representative while employees were working with it. Enough source term data 

(process description) to bound exposure times without being unrealistically high. 

Dose Reconstruction Not Feasible 

Inadequate personnel or areas monitoring data and inadequate source term data and process information 

Mound SEC 0207 

ORANL SEC 0189 

Nuclear Metals SEC 0195 

Mound SEC 0090 (early years) 

Ventron SEC 0198 

Winchester SEC 0199 

Clarksville SEC0202 

Medina SEC 0203 

Hanford SEC 0201 

Sandia National Lab SEC 0188 

Brookhaven SEC 0196 

Clinton Engineering Works SEC 0178 

Electromet SEC 0136 

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Review of Parameters Associated with Defining Sufficient Accuracy

SEC Petition Feasibility Determination/Designation

HHS Designation/Determination Central Issue for Infeasibility SEC 0207 Mound (83.14) 

All employees of the Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked at the Mound Plant in Miamisburg, Ohio, from September 1, 1972, through December 31, 1972, or from January 1, 1975, through December 31, 1976, for a number of work days aggregating at least 250 work days, occurring either solely under this employment or in combination with work days within the parameters established for one or more other classes of employees in the Special Exposure Cohort. 

NIOSH determined that members of this class may have received radiatio

isotopes and progeny originating from residual radioactive material assocprocess conducted in the SW Building. The technologically-enhanced rado

19 and was potentially distributed throughout the R and SW buildings. NIOSH found no workplace monitoring records after February 1955 relevathe R and SW buildings until air measurements were made in 1979 and 19data for the residual Ra-Ac-Th source term affecting Room SW-19 and it sthroughout the SW building and the corridor of the R building, which was building. Therefore, NIOSH has concluded that it lacks sufficient monitoriinformation to perform adequate individual dose reconstructions for worevaluation. From September 1, 1972, through December 31, 1972, and from January 31, 1976, NIOSH cannot determine which employees at the Mound facilitthe R and SW buildings. Consequently, NIOSH finds that it is not feasible accuracy, internal exposures to radon and resulting doses for the class of evaluation. 

Summary: 

Internal dose There is no personal monitoring data and no area monitoring data for the source of Radon produced from remaining radioactthe Ra-Ac-Th process. In addition, there is little information concerning the source strength and potential distribution of the sTherefore, the central issue for the infeasibility is an unmonitored source term with a lack of knowledge of the source strengtsource. 

SEC 0189 ORNL Based on NIOSH’s evaluation of available data, NIOSH concluded that it is 

All employees of the Department of Energy, its reconstruct with sufficient accuracy the internal doses at the Oak Ridge Npredecessor agencies, and their contractors and from: uranium exposures during the period June 17, 1943, through Decemsubcontractors who worked in any area at the exposures during the period from January 1, 1948, through July 31, 1955; Oak Ridge National Laboratory (X-10) in Oak exposures during the period from November 4, 1943, through December Ridge, Tennessee, from June 17, 1943, through periods of infeasibility yields a collective time period for dose reconstructJuly 31, 1955, for a number of work days 1943, through July 31, 1955. 
Review of Parameters Associated with Defining Sufficient Accurac

aggregating at least 250 work days, occurring 

either solely under this employment, or in combination with work days within the parameters established for one or more other classes of employees in the Special Exposure Cohort. 

NIOSH determined that it lacks sufficient information, which includes spedata, air monitoring information, process and radiological source informasimilar operations at other sites that would allow it to estimate the total ito all the principal sources of internal radiation for all workers who workeLaboratory (X-10) during the period from June 17, 1943, through July 31, information, NIOSH believes external dose reconstruction is feasible for t

Summary: 

Internal dose There is a lack of personal monitoring data, area monitoring data, and a lack of process and source term knowledge to develobecause of the lack of source term and process knowledge and the early years of operation surrogate data could not be used

SEC 0195 Nuclear Metal Inc. 

All Atomic Weapons Employees who worked at the facility owned by Nuclear Metals, Inc. (or a subsequent owner) in West Concord, Massachusetts, during the period from October 29, 1958, through December 31, 1979, for a number of work days aggregating at least 250 work days, occurring either solely under this employment, or in combination with work days within the parameters established for one or more other classes of employees included in the Special Exposure Cohort. 

Internal exposure monitoring data available to NIOSH include: urine bioas

the evaluation period except 1968, 1972, and 1975 (with the number of udramatically from 1978 through 1983); approximately 500 lung counting summary air data for the pre-1975 period giving only maximum, minimumconcentrations; and 28,000 breathing zone and work area air sample resuthrough 1983. Based on NIOSH’s evaluation of available data, NIOSH concluded that it is doses for internal exposure because: (1) the early bioassay program (pre-and NIOSH cannot verify that available data represents the worse-case exdata are limited and not equivalent to breathing zone sampling; (3) NIOSH bioassay or air sample data for thorium operations; and (4) NIOSH did not data or indications of a thoron monitoring program for the thorium sourcTherefore, NIOSH concludes that it is not feasible for NIOSH to reconstrucinternal exposures to enriched uranium, thorium, uranium progeny, and tMetals, Inc. workers during the period from October 29, 1958, through Defound that it may be feasible to reconstruct internal doses from natural aemployees during the recommended SEC period from October 29, 1958, tusing available claimant and site monitoring data, and information in esta
Review of Parameters Associated with Defining Sufficient Accurac

Summary: 

Internal dose Inadequate personal and area monitoring data for uranium prior to 1983. In addition, a lack of process knowledge and source surrogate data. There is an unmonitored source term for thorium and a lack of process knowledge and source term to allow t

SEC 0090 Mound (Denial) 

All employees of the Department of Energy, Department of Energy contractors, or subcontractors who worked in any area at the Mound Plant in Miamisburg, Ohio, during the period from March 1, 1959, through December 31, 2007, except for workers who fall within the Special Exposure Cohort (SEC) classes established by SEC petitions 00171 and 00207. 

The principal source of internal and external radiation doses for members 

associated with the operations performed at the Mound Plant included explutonium, and tritium. These exposures were considered primary becauquantities and were use more widespread across the site. Secondary radiMound included uranium and thorium and their progeny, americium, curand radon isotopes, and protactinium. NIOSH determined that internal exposures during the operational period, those associated with existing Mound Plant SEC classes, can be bounded site. In its SEC-00090 Evaluation Report, NIOSH demonstrated that emplopotential for internal intake were monitored, and determined that the avused to reconstruct potential internal radiation doses for those employeeFor radionuclides for which exposures were routinely monitored, NIOSH hmodels that will be used to reconstruct internal doses for those workers wexposed, but not monitored. For reconstruction of internal exposures to rradionuclides that were infrequently monitored, NIOSH will rely on the avcombination with available air concentration measurements and process 

Summary: 

There’s adequate monitoring data for routinely used radionuclides. The monitoring data includes personal and area monitorimonitoring data is gross alpha which is used for all radionuclides. 

SEC 0116 United Nuclear (Denial) 

All site employees who worked in any area of the United Nuclear Corporation – Hematite, Missouri, site from January 1, 1958, through December 31, 1973, and the residual period January 1, 1974, through July 31, 2006. 

Bioassay and air sampling data are available in sufficient quantity and qua

the potential internal exposures for the UNC-Hematite class under evaluaoperational period. These data can also be used to support the evaluation internal dose over the site’s residual radioactivity period. Technical Basis Nuclear Corporation Hematite, Missouri, (DCAS-TKBS-0008). NIOSH can bdose associated with the weapons-related residual radioactivity that rem
Review of Parameters Associated with Defining Sufficient Accurac

AEC-related operations. 

The available air sample data, including breathing zone and general air daused to supplement the bioassay data, or as the primary source of internaperiod from 1961-1962. In addition, NIOSH has access to other radiologicinvestigation reports that support bounding internal dose for UNC-Hematthrough December 31, 1973, and the residual period January 1, 1974, thro

Summary: 

There’s adequate personal monitoring data and area monitoring data for uranium. There is a two year gap in bioassay data, band after the gap with validation from air sampling during the gap supported the conclusion that the co-worker model providduring the gap period. The thorium operations were done over a short period (6-8 months) and there was good area monitordescription of the source term and process. 

0198 Ventron NIOSH has not located documentation indicating the existence of a routin

All Atomic Weapons Employees who worked for exposure monitoring program for the period under evaluation. The very the Ventron Corporation at its facility in Beverly, and air sample data available to NIOSH are sparse and there is no evidencMassachusetts, from November 1, 1942, through are representative of the most highly-exposed workers at the Ventron facDecember 31, 1948, for a number of work days sample results are representative of all workers. Without additional persaggregating at least 250 work days, occurring data representing the period from 1942 through 1948, NIOSH does not haeither solely under this employment, or in appropriately characterize intakes of radioactive material intakes during ocombination with work days within the Corporation facility. parameters established for one or more other classes of employees included in the Special NIOSH does not have access to sufficient personnel monitoring, workplacExposure Cohort. data to estimate internal and external exposures for Ventron workers dur

and smelting operations from November 1, 1942, through December 31, 

Summary: 

Internal and External There is inadequate personal and area monitoring data. In addition, the years of operation were before HASL existed and theair monitoring program existed in the AEC complex. There is inadequate source term and process information to develop an model. Also, the early years of operation with the lack of source term and process information prevent using surrogate data. 
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0199 Winchester (83.14) 

All employees of the Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked at the Winchester Engineering and Analytical Center in Winchester, Massachusetts, from January 1, 1952, through December 31, 1961, for a number of work days aggregating at least 250 work days, occurring either solely under this employment or in combination with work days within the parameters established for one or more other classes of employees in the Special Exposure Cohort. 

NIOSH determined that the principal sources of internal and external radi

of the proposed class included exposures to uranium and thorium, includradionuclides, as found in various grades of ores, raffinates, and process efacility for analysis. NIOSH identified limited personnel internal monitoring data for select ind1954, and 1955. The data are not comprehensive and there is no evidencrepresentative of the most highly-exposed workers at the Winchester facavailable sample results are representative of all workers. Without additimonitoring data representing the period from 1952 through 1961, NIOSH to appropriately characterize radioactive material intakes during DOE opeEngineering and Analytical Center. NIOSH located little documentation as to the quantities of radiological maprocessing or testing. It is clear from reports and worker communication turanium and thorium. NIOSH also inferred from research reports that varbearing materials were used in the sites’ research. However, without addNIOSH is unable to ascertain the quantity or forms of the source materialstored on site at any time during the period under evaluation. In the absence of adequate internal dose monitoring criteria and personnhas not found sufficient general area air sampling, breathing zone air samterm information to allow it to bound potential exposures, or to demonstadequately monitored for potential exposure to radioactive material at thperiod. Consequently, NIOSH finds that it is not feasible to estimate with internal dose for workers at Winchester Engineering and Analytical CenteJanuary 1, 1952, through December 31, 1961. 

Summary: 

Internal dose The site had uranium ore and by-product materials with sporadic personal and area monitoring. When dealing with ore mateinformation are required to bound the dose to the uranium and thorium progeny. In addition, the dis-equilibrium in radionucmaterials created from processing the ore makes it difficult to create sufficiently accurate bounding doses for the progeny witAlso for this site, there is inadequate source term and process information to develop an exposure model or to allow the use 
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SEC 0202 Clarksville 

All employees of the Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked at the Clarksville Modification Center, Ft. Campbell, in Clarksville, Tennessee, from August 1, 1949, through December 31, 1967, for a number of work days aggregating at least 250 work days, occurring either solely under this employment, or in combination with work days within the parameters established for one or more other classes of employees included in the Special Exposure Cohort. 

The principal sources of internal radiation exposures for members of the 

Center, Ft. Campbell proposed class included exposures to tritium as a gahighly-enriched uranium, depleted uranium, polonium-210 in a Po-Be neuactivities of cesium-137 during the assembly, inspection, and disassembly NIOSH has found that air monitoring for tritium was called for in the plant However, NIOSH has been unable to locate recorded results of this monitidentified a lack of information indicating urinalysis or other forms of inteconducted to monitor for intakes of uranium, plutonium, or tritium. NIOSH has located very little documentation as to quantities of radiologicClarksville Modification Center, Ft. Campbell, for processing or testing. It worker communication that the Clarksville employees worked with uraniuHowever, without additional documentation, NIOSH is unable to ascertain the source materials that may have been used or stored on site at any timevaluation. In the absence of adequate internal dose monitoring criteria and adequatNIOSH has not found sufficient general area air sampling, breathing zone source term information to allow it to bound potential internal exposuresworkers were adequately monitored for potential exposures. Therefore, Nfeasible to estimate with sufficient accuracy the total internal dose for woModification Center, Ft. Campbell, in Clarksville, Tennessee, during the pethrough December 31, 1967. 

Summary: 

Internal dose There is a lack of personal monitoring data, area monitoring data, and a lack of source term information to develop a model fradionuclides or use surrogate data. 
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SEC 203 Medina 

All employees of the Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked at the Medina Modification Center in San Antonio, Texas, from January 1, 1958, through December 31, 1966, for a number of work days aggregating at least 250 work days, occurring either solely under this employment, or in combination with work days within the parameters established for one or more other classes of employees in the Special Exposure Cohort. 

The principal sources of internal radiation exposures for members of the 

Center, Ft. Campbell proposed class included exposures to tritium as a gahighly-enriched uranium, depleted uranium, polonium-210 in a Po-Be neuactivities of cesium-137 during the assembly, inspection, and disassembly 

NIOSH has found that air monitoring for tritium was called for in the plant However, NIOSH has been unable to located recorded results of this monidentified a lack of information indicating urinalysis or other forms of inteconducted to monitor for intakes of uranium, plutonium, or tritium. NIOSH has located very little documentation as to quantities of radiologicClarksville Modification Center, Ft. Campbell, for processing or testing. It worker communication that the Clarksville employees worked with uraniuHowever, without additional documentation, NIOSH is unable to ascertain the source materials that may have been used or stored on site at any timevaluation. In the absence of adequate internal dose monitoring criteria and adequatNIOSH has not found sufficient general area air sampling, breathing zone source term information to allow it to bound potential internal exposuresworkers were adequately monitored for potential exposures. Therefore, Nfeasible to estimate with sufficient accuracy the total internal dose for woModification Center, Ft. Campbell, in Clarksville, Tennessee, during the pethrough December 31, 1967. 

Summary: 

Internal dose There is a lack of personal monitoring data, area monitoring data, and a lack of source term information to develop a model fradionuclides or use surrogate data. 
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SEC 0190 Titanium Alloys Manufacturing 

(Denial) All employees who worked in any area or building at Titanium Alloys Manufacturing from January 1, 1955, through December 31, 1956. 

The principal source of internal radiation doses for members of the evalu

ingestion of uranium and uranium progeny contained in dusts and fumes operations, and the principal source of external radiation doses was from gamma radiation emanating from uranium-bearing materials. NIOSH has determined that uranium internal exposures during the operatusing air concentration data measured during TAM’s operational period fDecember 31, 1956. NIOSH may choose to employ a more refined approaindividual doses based on information associated with individual claims. dose reconstruction methods, including best-estimate approaches that emoperations, if discovered, to complete individual dose reconstructions. NIOSH determined that although no external monitoring data are availabof Battelle-TBD-6000, can be used to bound the photon dose during the oJanuary 1, 1955, through December 31, 1956. 

Summary: 

Although there is no personal monitoring data, there is enough area monitoring data, process information, and source term dAnother factor in this determination was this was a uranium operation with no other isotopes of concern. 

SEC 0201 Hanford (83.14) 

All employees of the Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked at the Hanford Engineer Works in Richland, Washington, from July 1, 1972, through December 31, 1983, for a number of work days aggregating at least 250 work days, occurring either solely under this employment or in combination with work days within the parameters established for one or more other classes of employees included in the Special Exposure Cohort. 

NIOSH determined that the principal sources of internal radiation exposu

current proposed class at Hanford included exposures to HEU, U-233, tho200 and 300 Areas. Consistent with the NIOSH, DOE, and DOL determinations associated with in 2009, NIOSH has determined that the Hanford site-specific and claimanthe time period under evaluation continue to be insufficient to allow NIOmovements between the 200 and 300 Areas and other areas of Hanford devaluation. Furthermore, NIOSH has no indication that Hanford implemenbioassay programs sufficient to detect intakes of purified HEU, U-233, thoend of the period under evaluation. NIOSH is unable to assess whether an energy employee, or class of emplopotentially enter specific areas of the Hanford site having the potential exneptunium, and thorium during the period from July 1, 1972, through DecNIOSH cannot define individual worker exposure scenarios based on the a
Review of Parameters Associated with Defining Sufficient Accurac

during the evaluated period. 

NIOSH determined that it does not have sufficient source term informatiooperations. Consequently, NIOSH finds that it is not feasible to estimate, winternal exposures to HEU, U-233, thorium, or neptunium and resulting demployees during the period from July 1, 1972, through December 31, 19

Summary: 

There is a lack of personal and area monitoring data for enriched uranium, U-233, thorium, or neptunium for the period evalulack of source term and process information to develop an exposure model or allow the use of surrogate data. 

SEC 0139 Hangar 481 (Denial) NIOSH determined that no unsealed radioactive materials were handled n

All employees who worked at Hangar 481, materials stored at the Hangar 481 facility. Radioactive materials handled Kirtland Air Force Base (AFB), from March 1, were in sealed DOT-compliant containers and monitored in accordance w1989 through February 29, 1996. radiation and contamination levels on package exteriors. 

Based on the available information on the radiological program and potensources, NIOSH concluded that internal radiological exposures to Ross Avfrom services rendered for the DOE at Hangar 481 are unlikely to have ocSandia National Laboratories, being an adjacent facility, was used to provthe dose from ambient environmental internal dose during the covered pExternal dose records exist for many Ross Aviation personnel and the Radand Reporting System (REIRS) reported data have been verified using Ebe1990-1994. The individual results of these records or use of the highest dopersonnel, adequately bounds external dose for unmonitored workers. 

Summary: 

There is little potential for internal exposure for this site and operation. In addition, the personal monitoring data available abe reconstructed. 
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SEC 0188 Sandia National Lab 

All employees of the Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked in any area at Sandia National Laboratories in Albuquerque, New Mexico, from January 1, 1963 through December 31, 1994, for a number of work days aggregating at least 250 work days, occurring either solely under this employment, or in combination with work days within the parameters established for one or more other classes of employees included in the Special Exposure Cohort. 

NIOSH determined that principal sources of internal radiation for membe

included exposures to plutonium, tritium, uranium, americium, and fissioPotential exposure pathways could have involved the handling of these raburial operations and related research and support missions or exposure contamination associated with reactors and/or accelerators work. NIOSH found that source terms and associated exposures varied over the Considering the potential exposure scenarios, NIOSH finds it is unable to eexposures with sufficient accuracy for the period from January 1, 1963 thAdditionally, a contribution factor to the extension of the SEC class time pinternal dosimetry data from 1992 thru 1994 was found not suitable for dBased on the findings, NIOSH concluded that it is not feasible to estimate sufficient accuracy for all workers at the Sandia National Laboratories-Alb1, 1963 through December 31, 1994. The basis of this finding demonstrataccess to sufficient information to estimate either the maximum radiation member of the class or to estimate such radiation doses more precisely thestimate for that period. 

Summary: 

Internal dose A number of factors supported the infeasibility for this site. The site had difficulty retrieving personal and area monitoring reof the EEOICPA program. In addition, the site did not do a lot of personal and area monitoring during the period of the recommore than one radionuclide of concern (e.g., plutonium, tritium, uranium, americium, and fission and activation products) anover time. In addition, processes varied over time. Subsequently, the site’s incident based personal monitoring program and did not support developing a co-worker model that could have been used to bound unmonitored workers. 

SEC 0196 Brookhaven National Lab (83.14) NIOSH determined that principal sources of internal and external radiatio

All employees of the Department of Energy, its proposed class included exposures to plutonium, uranium, tritium, fission predecessor agencies, and their contractors and transuranic radionuclides, nuclear reactors, linear accelerators, radiograpsubcontractors who worked at the Brookhaven variety of other radioactive materials, which could have occurred during tNational Laboratory in Upton, New York, from accelerator operations, or the performance of research and development January 1, 1980 through December 31, 1993, for a number of work days aggregating at least 250 NIOSH has determined that, due to undocumented worker movements acwork days, occurring either solely under this claimant-specific information pertaining to work locations, it is unable to 
Review of Parameters Associated with Defining Sufficient Accurac

employment, or in combination with work days 

within the parameters established for one or more other classes of employees included in the Special Exposure Cohort. 

from potential exposure scenarios based on assigned work location. 

NIOSH lacks sufficient information, which includes in-vivo and in-vitro moallow it to estimate the potential internal exposures to which the proposeexposed. NIOSH evaluated the available personnel and workplace monitoinformation and determined that there are insufficient data for estimatinworkers at Brookhaven National Laboratory during the time period from JDecember 31, 1993. Consistent with its findings associated with SEC-113, NIOSH finds that it lawhich includes in-vivo and in-vitro monitoring data, to allow it to estimate potential internal exposures to various radionuclides to which the propossubjected. NIOSH has documented that it cannot complete the dose reconstructions sufficient accuracy for the employees who worked at the Brookhaven NatJanuary 1, 1980 through December 31, 1993. The basis of this finding demnot have access to sufficient information to estimate either the maximum any member of the class or to estimate such radiation doses more preciseestimate for that period. NIOSH determined that it did not have access to sufficient source or sourcassociated with Brookhaven National Laboratory operations to bound potfrom these radionuclides for the covered period. 

Summary: 

Internal dose A number of factors supported the infeasibility for this site. The site had difficulty retrieving personal and area monitoring reEEOICPA program. In addition, the site did not do a lot of personal and area monitoring during the period of the recommendthan one radionuclide of concern (e.g., plutonium, tritium, uranium, americium, and fission and activation products) and the time. In addition, processes varied over time. Subsequently, the site’s incident based personal monitoring program and limitnot support developing a co-worker model that could have been used to bound unmonitored workers. 
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SEC 0178 Clinton Engineering Works NIOSH has determined that the principal sources of internal radiation for 

All employees of the Tennessee Eastman class included exposures to uranium residues as well as African and domeCorporation (1943-1947) and the Carbide and inhalation and ingestion of airborne uranium dust, and exposure from thoCarbon Chemicals Corporation (1947-1949) who radon progeny. were employed at the Clinton Engineer Works in Oak Ridge, Tennessee, from January 1, 1943 NIOSH has determined that based on the lack of thorium, radium, radon athrough December 31, 1949 for a number of for Clinton Engineer Works Elza Gate warehouse workers during the storawork days aggregating at least 250 work days, operations conducted during the period from January 1, 1943 through Deoccurring either solely under this employment or dose reconstruction from all potential sources of exposure is not feasible. in combination with work days within the parameters established for one or more classes of employees included in the Special Exposure Cohort. 

Summary: 

Internal dose The site had a lack of personal and area monitoring data to support bounding internal and external dose from uranium ores athere is a lack of source term and process information to develop an exposure model or allow the use of surrogate data. 

SEC 0136 Electro Metallurgical 

All employees of the Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked at the Electro Metallurgical site in Niagara Falls, New York, from August 13, 1942 through December 31, 1947, for a number of work days aggregating at least 250 work days, occurring either solely under this employment, or in combination with work days within the parameters established for one or more other classes of employees included in the Special Exposure Cohort. 

NIOSH has determined that the principal sources of internal radiation for 

class included exposures to uranium and its short-lived progeny present iand scrap recovery operations. The modes of exposure were inhalation agenerated during the various processes. NIOSH finds it is not feasible to estimate internal exposures with sufficienthe site from August 13, 1942 through December 31, 1947. Internal monradiological monitoring data, and source term data are not sufficient to pestimate of the bounding internal dose during this early period at the ElecNIOSH has determined that neither the bioassay nor the early limited air to bound the dose at Electro Metallurgical for the August 13, 1942 througof the period under evaluation. Based on health improvements described the internal dose related data collected after 1947 cannot be extrapolateprior to 1948 at Electro Metallurgical. 
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Summary: 

Internal dose
­There is inadequate personal and area monitoring data. In addition, the years of operation were before HASL existed and theair monitoring program existed in the AEC complex. There is inadequate source term and process information to develop an Also, the early years of operation with the lack of source term and process information prevent using surrogate data.
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