National Institute for Occupational Safety and Health

Sandia National Laboratories - Albuquerque

SEC-00188 Addendum 2

Charles Nelson, MS

DCAS SEC Team Lead

Advisory Board on Radiation and Worker Health (ABRWH) Meeting

April 28, 2022
Summary of SEC-00188 Petition History

 Petition qualified (83.13) for evaluation: October 21, 2011

 Petitioner proposed class definition:

• All Security Inspectors, Security Clerks, Firemen, Non-regular Recurrent Security 

Inspectors, Security Officers, Security Police Officers I, Security Police Officers II, 

Security Police Officers III, and Central Alarm System Operators that worked in 

any area at SNL-A for the period from January 1, 1963, through May 21, 2011

 NIOSH proposed the following class to be added to the SEC on February 21, 2012:

• All personnel that worked in any area at Sandia National Laboratories in 

Albuquerque, New Mexico for the period from January 1, 1949, through 

December 31, 1994
Basis for 1949-1994 SEC Class

 Insufficient monitoring data and information to reconstruct internal dose from 

January 1, 1949 through December 31, 1994:

• Lack of internal monitoring program documentation

• Lack of internal monitoring data

• Lack of process information 

 The Evaluation Report published February 21, 2012, concluded that external 

doses, including medical X-rays performed onsite as a condition of 

employment can be reconstructed for the duration of the evaluation period 

January 1, 1949, through May 21, 2011

• Continued evaluation since publication of the 2012 report has not identified 

any information which would contradict this conclusion regarding external 

dose
Summary of SEC-00188 Addendum (1995-1996)

 NIOSH proposed the following class to be added to the SEC on July 26, 2018:

• All personnel that worked in any area at Sandia National Laboratories in 

Albuquerque, New Mexico for the period from January 1, 1995, through 

December 31, 1996
Basis for 1995 – 1996 SEC Class

 Internal monitoring program concerns

 Air monitoring data deficiencies

• Uncertainties and concerns associated with the transitional and 

developmental nature of SNL-A’s internal monitoring program

• The site was making several improvements in the internal monitoring 

program including an increase in the use of personal and area air monitoring

• The program seemed to be lacking formalization in that NIOSH did not find 

adequate evidence that some key implementing procedures were fully in 

place until 1996 & 1997
SEC-00188 Addendum 2 (1997 – 2011)

The focus of Addendum 2 was determining Internal Dose Reconstruction feasibility:

 Determine suitability of monitoring program and documentation 

 Determine monitoring data sufficiency

 Address security guards’ monitoring concerns
Data Sources Reviewed for SEC-00188 Addendum (1/2)

 21 Interviews with 17 people

 1 Site data capture effort/trip since last SEC designation

 4 Written data capture requests

 Over 900 relevant documents captured and reviewed since SEC-0188 was issued in 

2012 (NIOSH has over 5,500 total documents in its database pertaining to SNL-A):

• Internal procedures and memos

• 10 CFR pt. 835 Compliance and self-assessment reports/memos

• Facility and process information

• Radiation Work Permits

• Incident reports

• Air monitoring data

• Internal and external radiological program audits and assessments
Data Sources Reviewed (2/2)

 Extracts from SNL-A’s “WebDose” database which the site uses for bioassay 

monitoring and as a reporting tool

 Internal/external monitoring records

 Breathing Zone (BZ) monitoring and air sample records

 Derived Air Concentration (DAC)-hour tracking
Available Internal Monitoring (1/3) 

WebDose Urine Bioassay

Year Non-H3 Sample Results Persons Sampled (NonH3) H3 Sample Results Persons Sampled (H3) 

1997 111 45 238 100

1998 144 59 375 126

1999 187 67 440 83

2000 119 46 375 50

2001 90 39 426 58

2002 111 46 575 78

2003 160 55 679 78

2004 158 51 677 70

2005 172 60 647 69

2006 128 40 500 51

2007 115 35 438 47

2008 101 33 424 40

2009 121 42 435 40

2010 138 48 446 39

2011 165 47 534 54

Total 2020 317 7209 362
Available Internal Monitoring (2/3) 

WebDose WB/Thyroid Count Data

Year Measurements Persons Monitored

1997 59 54

1998 66 55

1999 58 52

2000 265 40

2001 73 33

2002 54 43

2003 102 61

2004 60 46

2005 65 58

2006 61 54

2007 45 42

2008 29 28

2009 48 40

2010 40 39

2011 90 50

Total 1115 207
Available Internal Monitoring (3/3)

Total Available BZ Samples

Year Alpha BZ Results Beta/Gamma BZ 

Results Tritium BZ Results

1997 357 357 0

1998 1587 1587 0

1999 708 708 0

2000 347 347 0

2001 179 179 0

2002 408 408 0

2003 394 394 90

2004 131 137 119

2005 177 177 165

2006 75 72 88

2007 111 170 52

2008 189 362 55

2009 211 444 0

2010 321 549 1

2011 311 606 0

Total 5506 6497 570
Change in Internal Dose Monitoring Program

 Starting in 1995, SNL-A shifted the emphasis of the Internal Monitoring Program 

from reliance on bioassay to the use of breathing zone sampling and workplace 

indicators such as radiological surveys and radiological conditions to determine if 

bioassays were required

 SNL-A’s position was that no individual was likely to receive an internal exposure of 

100 mrem

• This is stated in Internal Technical Basis documentation, the Radiation Protection 

Plan, and in external assessments performed in 1996 and 1999
Internal Dose Monitoring Program Evidence of Field 

Implementation (1/3)

 February 3, 1998, summary of Radiological and Mixed Waste Management Facility 

(RMWMF) safety committee discussion regarding routine bioassay 

• “The RCTs at the RMWMF are on routine bioassay. If a trend developed indicating 

internal doses, RMWMF personnel would undoubtably [sic] be asked to submit 

special bioassay samples to determine the scope of the problem.”

• “If trends developed indicating elevated air concentrations or increased surface 

contamination levels, special bioassay samples would be requested from 

appropriate facility personnel.”

• “Job specific RWPs require bioassay, as appropriate, for those workers involved 

with tasks where significant levels of radionuclides, or certain specific 

radionuclides (e.g., 3H) are handled.”
Internal Dose Monitoring Program Evidence of Field 

Implementation (2/3)

 May 30, 2001, memo documenting the routine bioassay program for RCTs at TA-V

• “The current schedule calls for annual whole body counting and semi-annual 

urinalysis samples for U, Th, Am, and Pu.”

• “The SNL bioassay program is confirmatory in nature. The bioassay program 

confirms the results and effectiveness of contamination control and other 

personnel protection activities.”

• “Since Radiological Control technicians (RCTs) must be present in all work activities 

where the possibility of meaningful intakes is credible, their bioassay serves as a 

good proxy indicator for potentially exposed line personnel,...”
Internal Dose Monitoring Program Evidence of Field 

Implementation (3/3)

 Captured RWPs and work planning documents were reviewed for indication of 

airborne radioactive material, respiratory protection, personal/area air monitoring 

requirements, and bioassay

 Indications of surface and airborne radioactive materials were noted as was the use 

of respiratory protection, personal and/or area air monitoring requirements, and 

bioassay

 Review of RWPs supports Rad Program adherence to contemporary procedures
Analysis of Breathing Zone (BZ) Data

In order to evaluate the internal dose associated with BZ filters, the following steps 

were performed

 Intake quantity associated with each BZ filter was determined

 Committed Dose associated with the intake quantities were calculated and based 

on the stochastic Annual Limit on Intake (ALI) for the limiting nuclide for the 

analysis type (i.e., gross alpha, beta/gamma, tritium)

 Committed Dose analyzed to determine the distribution of the data grouped by 

event. An event is defined two ways: a radiological work task at a given location on 

a given day, and all radiological work on a given day
Results of Analysis of Breathing Zone (BZ) Data (1/2)

 The results of the NOSH BZ Data Analysis was that the median quantity of 

radioactive material available for internal uptake to individuals located alongside 

personnel performing radiological work would correspond to an internal dose of 

0.5 mrem per work event or per workday 

• This dose quantity assumes that the individual is present inside the work area 

with no respiratory protection being used

• The unmonitored individuals to whom this dose is assigned would not have 

been located in the radiological work area along side of the monitored 

workers. A significant reduction in intake potential would occur due to the 

separation between the actual work area and an area that can be occupied 

without the same level of radiological controls 

• Although respiratory protection was worn during many work events where 

BZ were used, respiratory protection was not considered in the dose 

calculation
Results of Analysis of Breathing Zone (BZ) Data (2/2)

 Considering these conservative assumptions, NIOSH concluded that it is not likely 

that an individual would be able to receive 100 mrem per year of internal 

exposure under these conditions (i.e., an individual would have to be present for 

200 events, based on the median dose, to receive an exposure in excess of 100 

mrem in a year)
Assigned Committed Dose (rem); WebDose: 1997 – 2011

Year H3 BZ Urine Thyroid Total

1997 0 0 0 0 0

1998 0 0.010 0 0 0.010

1999 0 0 0 0 0

2000 0 0 0 0.005* 0.005

2001 0 0 0 0 0

2002 0 0 0 0 0

2003 0 0.012* 0 0 0.012

2004 0 0 0 0 0

2005 0 0 0 0 0

2006 0 0 0 0 0

2007 0 0 0 0 0

2008 0 0 0 0 0

2009 0 0 0.023 0 0.023

2010 0 0.004 0.019 0 0.023

2011 0.004 0 0 0 0.004

Total 0.004 0.026 0.042 0.005 0.077

* Indicates dose was distributed among multiple individuals.
Feasibility of Dose Reconstruction 1/1/97 – 5/21/11 (1/3)

 Based on its review of radioactive material use at Sandia-Albuquerque and the 

associated radiation protection programs, NIOSH has concluded that intakes for 

unmonitored workers with access to controlled areas were unlikely to have resulted 

in committed effective dose equivalents (CEDE) in excess of 100 mrem per year 

 This conclusion is not wholly based upon the implementation of 10 C.F.R. §

835.402, but rather on a review of exposure monitoring records for individuals 

involved in radiological activities with the highest risks at the site during the period 

under evaluation

 The total assigned internal dose (CEDE) for all employees combined for the 15-year 

period from 1997 through 2011 is 77 mrem 
Feasibility of Dose Reconstruction 1/1/97 – 5/21/11 (2/3)

 A review of available breathing zone bioassay data indicates that the median 

quantity of radioactive material available for internal uptake to individuals located 

alongside personnel performing high-risk radiological work would correspond to an 

internal dose of 0.5 mrem per work event or per workday 

• Assumes the individual is present within the work area alongside of worker

• Assumes no respiratory protection/breathing same concentration of air as worker

 In either case, consistent with the recorded internal dose of 77 mrem above, it is 

not likely that an individual would receive 100 mrem per year of internal exposure 

under these conditions

• An individual would have to be present for 200 events, based on the median 

dose, to receive an exposure in excess of 100 mrem in a year
Feasibility of Dose Reconstruction 1/1/97 – 5/21/11 (3/3)

 As previously identified in SEC-00188 Evaluation Report in 2012, NIOSH finds it is 

feasible to reconstruct occupational medical doses and principal sources of 

external radiation exposure including beta, gamma, and neutron radiation for 

Sandia National Lab-Albuquerque employees with sufficient accuracy

 Considering the potential exposure scenarios, program policies, procedures, 

available monitoring data, and confirmation of low doses among monitored 

workers, NIOSH finds it is feasible to reconstruct internal doses with sufficient 

accuracy for the period

 NIOSH found no part of the class under evaluation for which it cannot estimate 

radiation doses with sufficient accuracy
Feasibility Findings

SEC-00188, Addendum 2

(January 1, 1997 – May 21, 2011)

Source of Exposure Dose Reconstruction is

Feasible

Internal – All Radionuclides Yes

External – Beta/Gamma Yes

External – Neutron Yes

External – Occupational Medical X-Ray Yes