National Institute for Occupational Safety and Health

Sandia National Laboratories - Albuquerque

SEC-00188 Addendum 2

Charles Nelson

Health Physicist

Advisory Board on Radiation and Worker Health (ABRWH) Meeting

Pittsburgh, Pennsylvania| April 17, 2019
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 2/21/12 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 Petition History

 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 (Jan. 1, 1997 – May 21, 2011)

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

 Determine suitability of monitoring program and documentation 

 Determine monitoring data sufficiency

 Address security guards’ monitoring concerns
Data Sources Reviewed

 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 C.F.R. 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, cont.

 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 

WebDose Urine Bioassay

Year Non-H3 Sample Results Persons Sampled (Non-H3) 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, cont.

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, cont. 

Captured BZ Data Sheets

Year BZ Sample Results

1997 367

1998 1583

1999 708

2000 336

2001 172

2002 585

2003 0

2004 274

2005 388

2006 208

2007 231

2008 445

2009 76

2010 26

2011 0

Total 5389
Internal Dose Monitoring Program Overview

 SNL-A shifted the emphasis of the Internal Monitoring Program from reliance on 

bioassay to the use of breathing zone sampling as a primary method of monitoring

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

of 100 mrem

• This is stated both in the Internal Technical Basis documentation and in external 

assessments performed in 1996 and 1999

 SNL-A used a confirmatory bioassay monitoring program

• BZ monitoring was the primary method of internal dose monitoring

• The site did not rely solely on bioassay monitoring to assess potential exposure to 

SNL-A personnel
Changes to Monitoring Program

 Personal air sampling (PAS) indicated as the primary indicator of intakes at SNL-A 

 Described as a philosophical change in the internal dosimetry program. Change of 

emphasis from internal dosimetry to internal radiation protection and reliance on 

other types of monitoring to be indicative of the need for bioassay.

 Procedures on entering dose from PAS samples into dose tracking system

 Personal air sample results and dose records included in the Internal Dosimetry 

recordkeeping and retention requirements
Internal Dose Monitoring Program Evidence of Field 

Implementation

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

(RMWMF) safety committee discussion on need for 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, cont.

 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 exposure line personnel,...”
Internal Dose Monitoring Program Evidence of Field 

Implementation, cont. 

 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 requested

 Review of RWPs supports Rad Program adherence to contemporary procedures
Internal Dose Monitoring Program Evidence of Field 

Implementation, cont.

Date Triggering Event Summary Follow-up

02/07/97 Puncture wound [Incident description redacted] Bioassay Sampling

03/20/97 Area survey Unexpected surface contamination detected during post-job 

survey. Bioassay Sampling

04/16/97 Odor during opening 

drum

Upon opening drum, a strange odor was detected. Tritium 

contamination detected. Bioassay Sampling

05/29/97 Area monitor alarm Tritium monitor alarmed during work. Bioassay Sampling

02/12/98 Area survey Unexpected surface contamination detected during post job 

survey. Bioassay Sampling

07/23/98 Personnel contamination 

monitoring

Unexpected levels of contamination detected during work 

process. Work stopped, follow- up survey identified unexpected 

high levels of surface contamination. 

Bioassay Sampling

10/30/98 BZ air sample Unexpectedly high air sample result during work. WBC and Bioassay Sampling

01/19/99 BZ air sample Unexpectedly high air sample result during work. Bioassay Sampling

01/26/99 Area survey Unexpected surface contamination detected during post-job 

survey. Bioassay Sampling

03/19/99 BZ air sample Unexpectedly high air sample result during work. Bioassay Sampling
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 were determined

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

on the stochastic 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
Gross Alpha BZ Results

Year Available Alpha BZ Results Number of Individual Work Activities Number of Work Days with a Sample

1997 357 148 130

1998 1581 368 211

1999 708 186 120

2000 334 84 78

2001 172 90 82

2002 553 296 155

2004 131 53 44

2005 177 77 65

2006 75 33 32

2007 111 42 39

2008 189 68 63

2009 38 16 16

2010 23 6 6
Gross Alpha BZ Results, cont.

The median dose:

 0.48 mrem with an associated 

geometric standard deviation 

of 5.8 for an event defined by 

particular area and time

 0.51 mrem with a GSD of 5.2 

for all individuals working on a 

particular day
Gross Beta/Gamma BZ Results

Year Available Beta/Gamma BZ Results Number of Individual Work 

Activities

Number of Work Days with a 

Sample

1997 357 148 130

1998 1583 368 211

1999 708 186 120

2000 336 84 78

2001 172 90 82

2002 553 296 155

2004 137 53 44

2005 177 77 65

2006 72 32 32

2007 170 42 39

2008 358 68 63

2009 74 16 16

2010 26 6 6
Gross Beta/Gamma BZ Results, cont.

The median dose:

 0.001 mrem with an associated 

geometric standard deviation of 

8.0 for an event defined by 

particular area and time

 0.001 mrem with a GSD of 7.0 

for all individuals working on a 

particular day
Tritium BZ Results

Year Available Tritium BZ Results Number of Individual Work Activities Number of Work Days with a Sample

2004 119 45 39

2005 165 67 57

2006 88 41 39

2007 52 20 19

2008 8 5 5
Tritium BZ Results, cont.

The median dose:

 0.007 mrem with an associated 

geometric standard deviation of 

4.4 for an event defined by 

particular area and time

 0.007 mrem with a GSD of 4.3 

for all individuals working on a 

particular day
Assigned Committed Dose in WebDose: 1997 - 2011

Year H3 BZ Urine Thyroid Total

1997 0 0 0 0.000

1998 0 0.010 0 0 0.010

1999 0 0 0 0 0.000

2000 0 0 0 0.005 0.005

2001 0 0 0 0 0.000

2002 0 0 0 0 0.000

2003 0 0.012 0 0 0.012

2004 0 0 0 0 0.000

2005 0 0 0 0 0.000

2006 0 0 0 0 0.000

2007 0 0 0 0 0.000

2008 0 0 0 0 0.000

2009 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 0 0.077
Feasibility of Dose Reconstruction

 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 0.1 rem 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. 
Feasibility of Dose Reconstruction 1/1/97 – 5/21/11

 Internal monitoring records from monitored individuals are available within the 

SNL-A WebDose Database

 SNL-A implemented 10 C.F.R. 835 with the requirements for monitoring of 

individuals with a potential for internal exposure >100 mrem by January 1, 1995

 Internal dose for unmonitored individuals or individuals monitored solely by 

breathing zone sampling can be bounded using a 100 mrem presumptive exposure
Feasibility of Dose Reconstruction 1/1/97-5/21/11, cont.

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

period from 1997 through 2011 is 77 mrem 

 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 work day 

• Assumes the individual is present within the work area along side 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 be able to 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, cont.

 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

 As previously identified in SEC-00188 Evaluation Report, the principal sources of 

internal radiation for members of the proposed class included exposures to 

plutonium, tritium, uranium, americium, and fission and activation products 

• Potential exposure pathways could have involved the handling of these 

radionuclides during waste-burial operations or exposure to surface or air 

contamination associated with reactor and/or accelerator work

• Considering the potential exposure scenarios, program policies, procedures, and 

monitoring data availability, NIOSH finds it able to estimate these internal doses 

with sufficient accuracy for the period
Feasibility of Dose Reconstruction 1/1/97 – 5/21/11, cont.

 Based upon its analysis of the available resources, 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 – December 31, 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
Recommendation

Class Feasibility Health Endangerment

January 1, 1997 through October 21, 2011 Yes N/A