Page 1 of 14
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documents are not final NIOSH or ABRWH (or their technical support and review contractors) positions unless specifically
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To: LANL Work Group
From: Brant Ulsh
Subject: Weight of Evidence Supports NIOSH’s Ability to Bound LANL TA-53
Doses for 1996–2005: Evaluation of Radiological Work Permits
Date: February 22, 2024
This memorandum provides results and conclusions from NIOSH’s evaluation of
additional radiological work permits (RWPs) applicable to the 1996–2005 period for the
Los Alamos National Laboratory (LANL) Technical Area-53 (TA-53). The TA-53 includes
the Los Alamos Neutron Science Center (LANSCE), which contains accelerators and
various other experimental facilities focused on a broad base of neutron research. LANL
issued RWPs to inform workers of area radiological conditions within TA-53 and to
establish radiological controls for intended work activities [LANL 1998, PDF p. 5]. By
evaluating additional captured TA-53 RWP content and application in greater detail,
NIOSH is augmenting existing evidence supporting conclusions presented in the Weight
of Evidence Supports NIOSH’s Ability to Bound LANL TA-53 Doses for 1996–2005
memo [NIOSH 2023], as well as those in ORAUT-RPRT-0103, Review of Potential
Exposure to Exotic Radionuclides Using Radiological Work Permit Data at Los Alamos
National Laboratory [ORAUT 2022].
Concluding that NIOSH can bound workers’ radiation doses for TA-53 (or any area of
the LANL site) is based on demonstrating that LANL maintained and implemented an
appropriate Radiation Protection Program (and procedures) that required sufficiently
monitoring its workers. In addition to expanding the current, general knowledge of
LANL’s Radiation Protection Program, the information contained within captured TA-53
RWPs also supports specific prior conclusions. For example, the RWPs indicate that
work performed in beam areas, during and after beam operation, was regularly
assessed by LANL Health Physics personnel from hazard and exposure potential
standpoints, monitored appropriately, and that LANL Health Physics personnel used
administrative and engineering controls as necessary to keep exposures to the
workforce below 100 mrem/year and as low as reasonably achievable (ALARA).
Page 2 of 14
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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.
The following sections present data obtained directly from RWPs written for TA-53 from
1996 through 2005 [LANL 1942–2023].
Overview of RWP Data
During data capture activities performed in 2019 and 2023, NIOSH obtained copies of
all TA-53 RWPs identified by LANL staff for 1996–2005. While the collection of TA-53
RWPs identified by LANL staff is substantial (1,349 RWPs), the completeness of the
dataset is uncertain. It is possible that some RWPs were not correctly identified and/or
provided for NIOSH’s capture. It is also apparent that some captured RWPs may be
missing pages. Additionally noteworthy, is that available LANL procedures indicate
RWPs were not mandatory for all work in radiologically-posted areas. As stated in
LANL’s 1996 Standard Operating Procedure for Radiological Controls document,
“RWPs may or may not be required for work in radiologically posted areas as
determined by an RCT [radiation control technician] or the health physicist” [ LANL
1995–1999, PDF p. 19]. Recognizing these variables, some assessment limitations
necessarily exist. For example, NIOSH cannot link each documented TA-53 work event
with a corresponding RWP.
NIOSH has carefully evaluated all 1,349 RWPs for 1996–2005 over various locations
within TA-53 for the following: expected (listed) radionuclides, external monitoring,
elevated radionuclide air concentrations and intake monitoring, required personnel
protective equipment (PPE), health physics coverage, required training, and
contamination surveys and air monitoring. In addition to tallying these various RWP
associations and requirements, NIOSH has assessed and summarized (to the extent
practical given the dataset unknowns and size) the appropriateness of omitting or not
documenting certain RWP content (when observed). NIOSH further examined the
RWPs for cited documents such as integrated work documents, hazard control plans,
test plans, and laboratory implementation requirements.
RWP Evaluation Results
As a broad overview, NIOSH has summarized the 1,349 RWPs by applicable year
(Table 1) and their association with primary TA-53 locations (Table 2). The follow-on
discussions and tables summarize RWP composition for the aforementioned contents
for TA-53 and for the entire 1996–2005 period. Where considered useful, RWP content
associated specifically with the LANSCE beam line/flight path area has been parsed out
and/or discussed.
Page 3 of 14
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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.
Table 1: TA-53 RWPs (1996–2005) Grouped by Year
a
Year First Date Last Date Number of RWPs
Percentage
b
of
RWPs
1996
1/1/1996
12/31/1996
235
17.4%
1997
1/2/1997
12/31/1997
234
17.3%
1998
1/5/1998
12/31/1998
178
13.2%
1999
1/4/1999
12/31/1999
228
16.9%
2000
c
1/10/2000
12/31/2000
88
6.5%
2001
1/2/2001
12/31/2001
124
9.2%
2002
1/2/2002
12/31/2002
79
5.9%
2003
1/2/2003
12/31/2003
59
4.4%
2004
1/5/2004
12/31/2004
58
4.3%
2005
1/1/2005
12/31/2005
66
4.9%
a. Source: [LANL 1942–2023]
b. The percentage is based on the total number of evaluated RWPs (1,349).
c. LANL did not provide RWPs associated with approximately the first six months of 2000.
Table 2: TA-53 RWPs (1996–2005) Grouped by Location
a
Location
Number of
RWPs
Percentage
b
of
RWPs
All Areas
5
<1%
Area A 194 14.4%
Beam line/Flight Path 252 18.7%
Blue Room 75 5.6%
Boneyard
6
<1%
Experimental Area
107
7.9%
General Target Area
251
18.6%
High Resolution Spectrometer (HRS)
30
2.2%
Isotope Production Facility (IPF)
38
2.8%
Low Energy Demonstration Accelerator
5
<1%
Proton Storage Ring (PSR) 241 17.9%
Radioactive Liquid Waste/Waste Handling 35 2.6%
Support 102 7.6%
Time of Flight Isochronous Spectrometer 8 <1%
a. Source: [LANL 1942–2023]
b. The percentage is based on the total number of evaluated RWPs (1,349).
Page 4 of 14
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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.
Expected Radionuclides
Potential exposures to “exotic” radioactive materials associated with TA-53 work
activities is documented within the RWPs for 1996–2005. With respect to LANSCE,
exotic radionuclides included activation and spallation products produced by the
accelerator proton beam in the beam line/flight path area. Actinide sources, which
include radionuclides considered exotic, were also used in TA-53 and LANSCE
experiments. Actinide sources consisted of sealed sources and targets, bagged
unencapsulated sources and targets, neutron generators such as americium-beryllium
and plutonium-beryllium, and metallic target material. Other potential sources of actinide
exposure included source inventories and decontamination work.
Tables 3 and 4 summarize the number of RWPs containing the various types of
radionuclides identified as “expected”
1
radionuclides of interest. Table 3 presents results
from TA-53 as a whole (1,349 RWPs), and Table 4 presents a summary of the 252
RWPs associated only with beam line/flight path activities. To aid the summation of the
many different observed radionuclides of interest, mixed activation product
radionuclides and spallation product radionuclides were combined into a single category
denoted as “MASP” (mixed activation and/or spallation products). Similarly, the various
actinides noted were not tracked individually but simply denoted as actinides. The
presence or absence of cobalt-60 (Co-60) associated with the MASP radionuclides was
also tracked. This was done because NIOSH is separately evaluating a proof-of-
concept method to bound doses from intakes of all radionuclides for routine TA-53
workers based on Co-60 body burdens measured with LANL’s whole body counter.
1
The radionuclides of interest noted within the RWPs are typically labeled as “expected,” “measured,” or
“anticipated.” Though all radionuclides of interest have been tallied regardless of the label used, only the
“expected” label is used when presenting the evaluation results.
Table 3: TA-53 Expected Radionuclides Listed in RWPs (1996–2005)
a
Number
b
of RWPs
Percentage
c
of RWPs
d
741
54.9%
d
88
6.5%
20
1.5%
97
7.2%
407
30.2%
a. Source: [LANL 1942–2023]
b. Though the total number of captured TA-53 RWPs is 1,349, some RWPs listed both MASP and
actinides as radionuclides of interest. As such, the total number of RWPs on the table exceeds 1,349.
c. The percentage is based on the total number of evaluated RWPs (1,349).
d. Mixed activation and/or spallation product
Page 5 of 14
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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.
Examining additional RWP content and requirements within the 407 RWPs in which no
radionuclides of interest were noted, NIOSH observed that the exposure concerns with
the associated activities may have been limited to beta and gamma external dose
potential from mixed activation and spallation products. All but 4 of the 407 RWPs with
“None Identified” listed in Table 3 included a requirement for some type of external
dosimetry on their “radiation protection requirements” pages, such as:
thermoluminescent dosimeter (TLD), electronic personal dosimeter (EPD), neutron,
extremity, and/or pocket ion chamber. Four RWPs did not clearly identify external
dosimetry requirements:
• One had “special dosimetry” use indicated on its “post-job review” page. This
RWP also contained a dose tracking report, further supporting dosimetry use.
• Two did not include the “radiation protection requirement” pages but included
dose tracking reports, indicating dosimetry use.
• One did not stipulate external dosimetry requirements or contain the “post-job”
portion of the RWP, making dosimetry use uncertain.
Table 4: Beam Line/Flight Path Expected Radionuclides Listed in RWPs (1996–
2005)
a
Number of RWPs
Percentage
b
of RWPs
c
121
48.0%
5
2%
27
10.7%
99
39.3%
a. Source: [LANL 1942–2023]
b. The percentage is based on the total number of evaluated beam line/flight path RWPs (252).
c. Mixed activation and/or spallation product
External Monitoring
NIOSH evaluated each TA-53 RWP for external monitoring (dosimetry) requirements.
External monitoring via TLD was required in 1,331 RWPs (nearly 99%) with EPDs
required in 804 RWPs (almost 60%). The number and percentage of RWPs requiring
each type of external dosimeter is shown in Table 5. Note that individual RWPs
frequently specified multiple types of dosimeters.
Page 6 of 14
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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.
Table 5: TA-53 External Dosimetry Requirements in RWPs (1996–2005)
a
Type
Number
b
of RWPs
Percentage
c
of RWPs
TLD
1,331
98.7%
EPD
804
59.6%
Neutron
87
6.4%
Supplemental/Secondary
335
24.8%
Extremity
13
<1%
None
8
<1%
a. Source: [LANL 1942–2023]
b. Though the total number of captured TA-53 RWPs is 1,349, some RWPs specified requirements for
multiple types of dosimeters. As such, the total number of RWPs on the table exceeds 1,349.
c. The percentage is based on the total number of evaluated RWPs (1,349).
As noted in Table 5, specified dosimetry requirements (denoted as “None”) were not
present in 8 of the 1,349 TA-53 RWPs:
• Three stated that external dosimetry was not required and noted low dose rates.
• Two included EPD dose tracking reports, indicating EPD dosimetry was used.
• One did not include the radiation protection requirements page, making a
determination of dosimetry requirement/use impossible.
• One did not include a dose tracking page report, making a final assessment of
dosimeter use impossible.
• One contained a dose tracking page marked as “not applicable,” which could
possibly indicate that no external exposure potentials were expected.
As shown in Table 2, 252 of the 1,349 TA-53 RWPs were written for beam line/flight
path work. All but one of these RWPs required external dosimetry. The work associated
with the single RWP not requiring dosimetry was described as not posing an external
dosimetry hazard (in the RWP). It is noteworthy that LANL’s Personnel Access Control
System prevented entry into the beam line and flight paths during beam operations;
therefore, entry into those areas occurred before an operation started and after
cooldown [NIOSH 2023, PDF pp. 5–6].
Elevated Radionuclide Air Concentrations and Associated Worker Monitoring
NIOSH evaluated radionuclide air concentrations and associated worker monitoring
identified in TA-53 RWPs to expand current knowledge of the site’s RWP use to assess,
control, and monitor airborne radionuclide exposure potentials. NIOSH assessed RWPs
meeting any of the following three conditions:
• Reported radionuclide air concentrations equal to, greater, or possibly greater
than 10% Derived Air Concentration (DAC) for either pre-job or post-job work
Page 7 of 14
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documents are not final NIOSH or ABRWH (or their technical support and review contractors) positions unless specifically
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• Required nasal swipes
• Reported any air monitoring results while performing the job detailed in the RWP
Elevated Radionuclide Air Concentrations
Pre-job radionuclide air concentrations were identified as equal to, greater, or possibly
greater than 10% DAC in 28 (2.1%) of the 1,349 TA-53 RWPs. In each of these 28
RWPs, the pre-job air concentrations were described as “anticipated” (none were
measured values). Two of these 28 RWPs also noted estimated post-job values greater
than 10% DAC. In total, 18 of the 1,349 RWPs noted post-job values exceeding 10%
DAC; 5 had values measured, and 13 had values estimated.
NIOSH investigated RWP details associated with the five RWPs noting measured, post-
job air concentrations exceeding 10% DAC. One of the five RWPs recorded a post-job
air concentration of exactly 10 DAC. This RWP required continuous Radiation Control
Technician (RCT) coverage. However, no nasal swipes or respiratory requirements
were noted. A review of this RWP’s “Acknowledgement Log” and dose summary sheets
revealed that 11 of the 19 workers listed on the RWP had in vivo measurements
performed during the RWP work period or within a year after. The remaining four RWPs
contained measured DAC values ranging from less than 1 DAC to approximately 1.5
DAC. Three of these also stipulated continuous RCT coverage, while one required
intermittent RCT coverage. Only one of these four RWPs required respiratory
protection; five nasal smears obtained for this RWP were all below detection limits.
It is worth noting that none of the 97 RWPs listing actinides as expected radionuclides
(see Table 3) recorded airborne activity >10% DAC or positive nasal swipe results.
Worker Monitoring
LANL Health Physics personnel stipulated nasal swipe collection in 192 of the 1,349
TA-53 RWPs (14.2% of all RWPs). Table 6 summarizes the expected radionuclides for
those 192 RWPs requiring nasal swipes.
Table 6: Expected Radionuclides for TA-53 RWPs Requiring Nasal Swipes
a
Radionuclides
Number of RWPs
Percentage
b
of RWPs
Co-60 and other MASP
158
82.3%
Actinides
6
3.1%
None Identified
28
14.6%
a. Source: [LANL 1942–2023]
b. The percentage is based on the total number of RWPs stipulating nasal swipes (192).
For the six RWPs listing actinides as being expected, NIOSH found that none noted
area or personnel contamination, reported air concentrations were all less than 10%
Page 8 of 14
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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.
DAC, and all required respiratory protection. Notably, six RWPs associated with work in
the beam line/flight path area required nasal swipes; all results were reported as having
no detectable activity.
Aside from the nasal swipe requirements, no additional bioassay was initially indicated
as required on any TA-53 RWPs. As determined appropriate, however, follow-up
bioassay (e.g., in vivo, in vitro, or chest count) was performed.
At least one nasal swipe result was recorded in 91 of the 192 RWPs requiring nasal
swipes; in total, 802 nasal swipe results were recorded within these 91 RWPs. Within
the 802 nasal swipe results, two positive alpha results measured at 12 and 133
disintegrations per minute (dpm), and 30 positive beta results ranged from 48 dpm to
662 dpm.
LANL required initiation of Radiation Protection Observation Reports (formerly known as
Radiation Incident Reports) if the sum of readings in both nostrils for nasal swipes was
greater than or equal to 50 dpm for alpha, and/or greater than or equal to 500 dpm for
beta. A total of three individuals had nasal swipe results that exceeded these
thresholds. Nasal swipes for one of the individuals indicated beta results above 500
dpm. Follow-up in vivo monitoring was performed for this person, and the results
showed no detectable activity. The Radiation Protection Observation Report initiated for
this individual also noted that LANL Health Physics staff suspected the elevated nasal
smears were a result of cross-contamination. A second Radiation Protection
Observation Report was initiated for an employee whose nasal swipes exceeded both
the alpha and beta action limits. No information regarding follow-up bioassay was
observed in this report. However, NIOSH determined this individual was on routine in
vivo bioassay, and none of this person’s results were greater than the minimum
detectable activity. The third Radiation Protection Observation Report was initiated for
an employee (unidentified) whose nasal swipes exceeded the beta limit.
Seven individuals identified as having positive nasal smears below limits either received
special request chest counts and/or were on a routine in vivo program. One of the
seven results had no associated name. One of the other individuals did not appear to be
on a routine bioassay program but did have a baseline whole body count and in vitro
results approximately six months before the nasal swipes were taken.
Though NIOSH cannot confirm, the absence of nasal swipe results in 101 of the RWPs
may result from on-the-job adjustments to monitoring requirements. As often noted in
RWPs, attendant RCTs had the authority to adjust monitoring (and PPE) as they felt
necessary, and 80 of the 101 RWPs included such stipulations. Of the remaining
RWPs, 16 contained no indication that nasal swipes were needed in the “post-job
review” section. However, of those 16 RWPs, 3 RWPs stated “no information available,”
so those appear incomplete. An additional 4 RWPs had associated “post-job review”
sections indicating that nasal swipes were taken, but records of the results are not
Page 9 of 14
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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.
evident. One RWP contained a “sample analysis” form indicating nasal swipes were
obtained from five individuals, but results were not indicated within the RWP.
Personal Protective Equipment
NIOSH assessed LANL-identified PPE requirements for all 1,349 TA-53 RWPs. Table 7
summarizes the types of PPE LANL required and the number/percentage of RWPs
specifying each type.
Table 7: TA-53 PPE Requirements in RWPs (1996–2005)
a
Type
Number
b
of RWPs
Percentage
c
of RWPs
Level 1
d
386
28.6%
Level 2
e
323
23.9%
Gloves
f
264
19.6%
Booties
f
32
2.4%
Gloves with booties
f
27
2.0%
Anti-splash/Waterproof Anti-
contamination clothing
26 1.9%
Skull cap/Hood
348
25.8%
Taped openings
399
29.6%
Full-face respirator
221
16.4%
None
266
19.7%
Other
g
85
6.3%
Unknown (PPE page not included)
5
<1%
a. Source: [LANL 1942–2023]
b. The total number of RWPs is 1,349. More than one type of PPE may be specified in an RWP.
c. The percentage is based on the total number of evaluated RWPs (1,349).
d. Level 1 PPE includes coveralls, two pairs of surgeon’s gloves, and booties.
e. Level 2 PPE includes two coveralls, two pairs of surgeon’s gloves, and two pairs of booties.
f. Gloves and booties in this table were only counted when Level 1 or 2 were not required.
g. Other PPE was typically determined by the RCT based on current, pre-job, or initial entry into an
area. Note that RCTs typically had the discretion to relax or increase PPE requirements based on
current contamination or radiological conditions.
One or more types of PPE were required in 983 (73%) of the TA-53 RWPs. Level 1 or
Level 2 PPE was required in 709 of the 1,349 TA-53 RWPs (52.6%). No PPE was
prescribed in 266 (19.7%) of the RWPs.
NIOSH reviewed all 266 RWPs that did not prescribe PPE use. They reviewed the
following fields: RWP number, effective date, expiration date, expected radionuclides,
description of work, surface contamination and/or air monitoring, airborne activity >10%
DAC, and nasal swipes (yes or no). External radiation exposure was the primary
concern in these 266 RWPs. No elevated DACs or nasal swipes requirements/results
were noted in any of them. Most of the associated work was for inspections, equipment
Page 10 of 14
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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.
installation and repair, operational checks, and general maintenance. The majority (250
of 266, or 94%) also required intermittent or continuous RCT coverage. As noted
previously, RCTs typically had the authority to adjust PPE and monitoring requirements
if any unusual or unexpected contamination or radiation exposure levels were detected.
As shown in Table 2, 252 of the 1,349 TA-53 RWPs were written for beam line/flight
path work. Some level of PPE was required in 157 (62%) of these RWPs, with Level 1
or Level 2 PPE required in 63 of the 157 (40%) [LANL 1996; LANL 1942–2023]. As
noted previously, LANL’s Personnel Access Control System prevented entry into the
beam line and flight paths during beam operations. Therefore, entry into those areas
occurred before the start of an operation and after a time of cooldown [NIOSH 2023,
PDF pp. 5–6].
Health Physics Coverage
All TA-53 RWPs required some type of Health Physics coverage. Types of coverage
included intermittent, continuous, and equipment (or “other”) surveys. Table 8 provides
the total number of RWPs specifying each type of coverage for the 1,349 TA-53 RWPs.
Table 9 provides the same information for the 252 RWPs associated with the beam
line/flight path area.
Table 8: TA-53 Health Physics Coverage Requirements in RWPs (1996–2005)
a
Type of Health Physics
Coverage
Number of RWPs Percentage of RWPs
b
Intermittent
398
29.5%
Continuous
908
67.3%
Equipment/Other
43
c
3.2%
a. Source: [LANL 1942–2023]
b. The percentage is based on the total number of evaluated RWPs (1,349).
c. This total includes 5 RWPs for which actual coverage is unknown. This is due to missing monitoring
requirements pages.
Table 9: TA-53 Beam Line/Flight Path Health Physics Coverage Requirements in
RWPs (1996–2005)
a
Type of Health Physics
Coverage
Number of RWPs Percentage of RWPs
b
Intermittent
128
50.8%
Continuous
110
43.6%
Equipment/Other
14
5.6%
a. Source: [LANL 1942–2023]
b. This percentage is based on the total number of RWPs associated with the TA-53 beam line/flight
path health physics coverage requirements (252).
Page 11 of 14
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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.
RWP Health Physics coverage noted as “Equipment/Other” included work such as
general inspections, checking entries, cables, vacuum recovery after power outages,
maintenance and repair work, operational checks, and swiping various materials and
equipment prior to release. These data corroborate the description of RCT coverage
provided in Section 1.2 of ORAUT-RPRT-0103, Review of Potential Exposure to Exotic
Radionuclides Using Radiological Work Permit Data at Los Alamos National Laboratory
[ORAUT 2022, PDF p. 10].
Required Training
NIOSH evaluated each RWP for required job training and identified the following
requirements: Department of Energy (DOE) Radiological Worker I, DOE Radiological
Worker 2, and facility-specific (TA-53/LANSCE) training (Table 10). DOE Radiological
Worker 1 training was required in 1,240 (almost 92%) of the RWPs. Many RWPs
included both radiological worker training and facility-specific training.
Table 10: TA-53 Training Requirements in RWPs (1996–2005)
a
Required Training
Number
b
of RWPs
Percentage
c
of RWPs
Radiological Worker 1
176
13.0%
Radiological Worker 1 +
Radiological Worker 2
1,064 78.9%
Facility Specific
848
62.9%
a. Source: [LANL 1942–2023]
b. Though the total number of captured TA-53 RWPs is 1,349, some RWPs specified multiple training
requirements in a single RWP. As such, the total number of RWPs on the table exceeds 1,349.
c. The percentage is based on the total number of evaluated RWPs (1,349).
Of the 252 RWPs written for work in the beam line/flight path area, 250 (99.2%)
required either Radiological Worker 1, Radiological Worker 2, facility-specific training, or
a combination of training. Note that the other two beam line RWPs training requirements
are unknown because the pages designating the training requirements were not
included.
Contamination Surveys and Air Monitoring
NIOSH evaluated the TA-53 RWPs to determine the extent of air monitoring and
contamination surveys conducted before, during, and after work completion. NIOSH
found the following:
• Pre-job surveys were performed for 1,244 RWPs (92.2%).
• Post-job surveys were performed for 1,052 RWPs (78.0%).
Page 12 of 14
This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) 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.
• 1,470 in-process surveys (not including pre-job, post-job, item release, offsite
shipment, or on-site shipment) were collected during the execution of 379 RWPs
(28.1%).
• Pre-job airborne radioactivity DAC values are “NA” for 299 RWPs and left blank
for 353 (48.3 % when combined).
• 207 RWPs contained air monitoring results obtained during jobs with the
potential for airborne radioactivity release.
• Post-job airborne radioactivity DAC values were marked as “NA” in 439 RWPs
and not noted in 495 (69.2 % when combined).
Determining whether or not any of the TA-53 RWPs failed to stipulate contamination
and/or airborne radioactivity measurements when such monitoring should have been
required is not currently possible, given the RWP investigative approach used for this
large-scale effort. Additional RWP analysis would likely provide more insight into this
question. An ever-present assessment factor that must also be considered is that LANL
did not require documentation of in-process surveys during work performed under
RWPs [Archuleta 2022, PDF p. 7].
ORAUT-RPRT-0103, Review of Potential Exposure to Exotic Radionuclides Using
Radiological Work Permit Data at Los Alamos National Laboratory, provides a detailed
examination of eight TA-53 RWPs [ORAUT 2022, PDF pp. 27–34]. This RWP review
concluded that LANL Health Physics personnel appropriately monitored work and the
work environments performed under RWPs. The review also concluded that when
contamination incidents occurred, LANL Health Physics personnel followed up with
appropriate monitoring and reporting when required.
Acknowledging the limitations of the current, large-scale TA-53 RWP assessment, it is
worth noting that no evidence directly negating conclusions from the in-depth RWP
assessment described above has been observed. Additionally, the current RWP
evaluation has noted that Radiation Protection Observation Reports were generated
(see the section on Worker Monitoring) when unexpected or unusual conditions arose.
Radiation Protection Observation Reports were associated with 25 (1.9%) of the 1,349
TA-53 RWPs.
Documents Cited Within RWPs
LANL provided supplemental information to many of the RWPs that were analyzed.
Many LANL RWPs referenced existing LANL procedures and safety-related documents.
Examples include standard operating procedures, hazard control plans, special work
permits, test plans, integrated work documents, and security plans. Some of the 1,349
RWPs also contained full-text copies of such documents. NIOSH’s evaluation
determined that 225 of the 1,349 TA-53 RWPs (16%) cited these document types.
Page 13 of 14
This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) 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.
Conclusion
NIOSH captured and evaluated 1,349 RWPs written for 1996–2005 LANL TA-53
activities to augment existing evidence supporting conclusions presented in Weight of
Evidence Supports NIOSH’s Ability to Bound LANL TA-53 Doses for 1996–2005
[NIOSH 2023] and ORAUT-RPRT-0103, Review of Potential Exposure to Exotic
Radionuclides Using Radiological Work Permit Data at Los Alamos National Laboratory
[ORAUT 2022]. The evaluations reported in these documents conclude that LANL’s
Radiation Protection Program was maintained and implemented in an appropriate
manner that sufficiently monitored its workers during this period and, as an integral part
of the protection program, LANL regularly utilized RWPs to assess work hazard and
exposure potentials, stipulate monitoring and PPE requirements, and mandated
administrative and engineering controls to maintain worker radiation doses under 100
mrem/year.
Observations from this larger scale RWP evaluation support the conclusions above. The
results indicate LANL Health Physics staff adequately monitored work areas and
workers in a manner commensurate with knowledge of work exposure potentials and
program procedures. Notably, NIOSH found that all TA-53 RWPs required some type of
Health Physics coverage and RWPs were used to control personnel radiation exposure
across all LANSCE areas (Table 2).
Additional summary information obtained from evaluating the 1,349 TA-53 RWPs
include:
• External monitoring use was stipulated in over 99% of the RWPs.
• Though elevated airborne radioactivity occurrences were not common, the
evaluated RWPs provide evidence of appropriate precautions, monitoring, and
follow-up bioassay when warranted.
• Radiation Protection Observation Reports were issued in the event of
unplanned/unexpected work events.
• Evidence of RCT authority to make on-the-job adjustments to monitoring and
PPE needs.
• Training requirements were consistently noted.
• A majority of RWPs stipulated pre- and post-job contamination surveys.
The results of this evaluation confirm the wide spread use of RWPs for 1996–2005 TA-
53 activities. It is evident that the RWPs incorporated knowledge of ongoing activities
and experience with TA-53 contamination conditions and hazards to identify and
stipulate appropriate requirements for work performed.
Page 14 of 14
This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) 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.
References
Archuleta S [2022]. LANL response to data request FY22-003 information related to the
bioassay program. Los Alamos National Laboratory, Los Alamos, NM. April 5. [SRDB
Ref ID: 192418]
LANL [1942–2023]. LANL SEC-00109 support files from May 2023 data capture. Los
Alamos National Laboratory, Los Alamos, NM. [SRDB Ref ID: 198792]
LANL [1995–1999]. RWPs and documentation associated with LANL experiments
(1995–1999). Los Alamos National Laboratory, Los Alamos, NM: University of
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LANL [1996]. RWP 96-219 remove comp. air regulator and replace it with spool piece
LANL TA-53 building 3 1996. Los Alamos National Laboratory, Los Alamos, NM:
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LANL [1998]. Work planning and radiological posting laboratory implementation
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NIOSH [2023]. Weight of evidence supports NIOSH’s ability to bound LANL TA-53
doses for 1996-2005. Correspondence to LANL Work Group. Cincinnati, OH: U.S.
Department of Health and Human Services, Centers for Disease Control and
Prevention, National Institute for Occupational Safety and Health. August 15. [SRDB
Ref ID: 198013]
ORAUT [2022]. Review of potential exposure to exotic radionuclides using radiological
work permit data at Los Alamos National Laboratory. Oak Ridge, TN: Oak Ridge
Associated Universities Team. ORAUT-RPRT-0103 Rev 00, August 15. [SRDB Ref ID:
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