ORAUT‐OTIB‐0070

Dose Reconstruction During Residual Radioa

Periods at Atomic Weapons Employer Fac

Report from the Procedures Review Subcom

Presented to the

ABRWH Full Board meeting

Augusta, Georgia

March 12, 2013
ORAUT‐OTIB‐0070 Summa

• Provides guidance for

– Estimating dose to workers at Atomic Weapons

Employer (AWE) facilities when NIOSH determin“significant residual contamination”

– Reconstruction of internal doses due to the

resuspension of particulate surface contaminati

• Only internal and external radiation exposur

defined in 42 U.S.C. §7384n(c)(4) are include

residual period dose reconstructions; exposfrom commercial sources is not used
ORAUT‐OTIB‐0070 Timelin

• March 10, 2008 – Revision 0

• August 29, 2008 – SC&A Review (SCA‐TR‐TASK3‐000

• July 14, 2010 – NIOSH Initial Responses• July 26, 2010 – Discussed with Subcommittee• December 30, 2010 – SC&A Reply to NIOSH Re

• January 5, 2012 – 2nd Discussion – Agreed on A

• March 5, 2012 – Revision 1• July 31, 2012 – 3rd Discussion – Findings Resolv
ORAUT‐OTIB‐0070, Revision 

• Provides guidance for reconstruction of in

doses due to the resuspension of particulasurface contamination

• Recommends ‐

– 6 methods for estimating internal exposure to 

radioactivity at AWE facilities depending on:

• Type of data available (air sample or surface conta

• Timing of data (operational and/or post‐operation

– Resuspension factor of 1×10‐6 m‐1, based on n

studies from 1964 to 2002

– Revision of 0.01 day‐1 source term depletion 

0.00067 in Rev 1, based on data from 4 AWE s
Findings Summary: OTIB‐00

• 15 Findings in total– complete histories capt

the Board Review System (BRS)

– http://app‐cinc‐dcas.cdc.gov:8106/documents/

default.aspx?mode=ASSIGNED

– Resolution spanned 4+years

– 14 findings are Closed

– 1 is Addressed in TBD‐6000 (also Closed)

• The following slides provide summary inform

resolution of each Finding – Details in BRS an

handout
OTIB‐0070 Review Finding

# Finding Resolution

1 Inconsistent use of the

resuspension factor (RF) –

The default source term

depletion value of the 1%

day‐1 implies a RF of 8e‐05

per meter, which is nearly 2

orders of magnitude higherthan NIOSH’s recommended

RF of 10‐6 m‐1.

Closed on July 31, 2012

OTIB‐0070, Revision 1 changed the 

depletion rate from 1% day‐1 to 0.00

which is consistent with a RF of 10‐6 
OTIB‐0070 Review Finding

# Finding Resolution

2 OTIB‐0070, Section 2.5

references Sehmel 1980, Tilland Meyer 1983, Linsley

1978, and Healy 1971. All of

these references are (except

Healy 1971) to outdoor soilcontamination, which involve

conditions with littleresemblance to building

surfaces, building uses, room

heights, and ventilation rates.

Closed on July 31, 2012

OTIB‐0070, Revision 1 recalculated 

source‐term depletion rate during 

radiation periods based actual data 

AWE sites (Blockson, Dow Madison

Atomics, and Simonds Saw) rather 

based on literature sources where 

measurements were preponderant
OTIB‐0070 Review Finding

# Finding Resolution

3 Implicit in deriving the

source term depletion rate(λ, Section 2.6) is that

airborne contaminants are

(1) uniformly distributedthroughout the interiorvolume and (2) removed

with 100% efficiency.Neither assumption is likely

to exist.

Closed on July 31, 2012

OTIB‐0070, Revision 1, Section 4.1 re

the default source‐term depletion ra

residual radiation periods based on a

observed depletion rates at four AW
OTIB‐0070 Review Finding

# Finding Resolution

4 Battelle‐TBDs‐6000/6001

identified relatively large air

concentrations during facilityoperations that were jobspecific. In contrast, OTIB‐

0070, Attachment B identifiesa single value for each of 3

thorium sites that excludes

process air sampling data.

Closed on January 5, 2011

Air samples were selected to be in

general area conditions within the the start of the residual period and potential exposure during the oper

period.
OTIB‐0070 Review Finding

# Finding Resolution

5 Attachment B cites survey

data for 3 thorium facilities,

but provides no furtherguidance on how these datasets are to be used.

Both Closed on January 5, 2011

Since it has never been used for DR 

Appendix B has been deemed unnec

the purpose of OTIB‐0070, and has b

removed from Revision 1. 6 Use of Horizons’ summary

survey data as a default

value for operational air

concentration at a thorium

refining facility isinappropriate and not

claimant favorable.
OTIB‐0070 Review Finding

# Finding Resolution

7 It is unclear how the

Attachment B Horizonsgeometric mean value of

4.8 dpm/m3 was derived

from the data contained inAEC 1955.

Both Closed on January 5, 2011

Since it has never been used for DR 

Appendix B has been deemed unnec

the purpose of OTIB‐0070, and has bremoved from Revision 1.

8 The derivation of Appendix

B air concentration values(i.e., a GM of 1.2 dpm/m3

and a GSD of 3.9 dpm/m3)

for Nuclear Metals from AEC1958 was not adequatelyexplained.
OTIB‐0070 Review Finding

# Finding Resolution

9 The derivation of the

Appendix B, Lindsey airconcentrations values wasnot adequately explained

and the values does not

appear to correspond to

those reported in the survey.

Closed on July 31, 2012

Since it has never been used for DR 

Appendix B has been deemed unne

the purpose of OTIB‐0070, and has 

removed from Revision 1.

10 NIOSH’s recommended RF of

10‐6 m‐1 is inappropriate. The

scientific literature indicates

RF values of 10‐4 to 10‐3 m‐1

for indoor activities involving

substantial industrialactivities.

Closed on July 31, 2012

A footnote added to Table 5‐1 indica

site by site analysis should be conduestablish the RF at sites where no p

operational clean‐up has been perfo

than simply accepting an RF of 10‐6 
OTIB‐0070 Review Finding

# Finding Resolution

11 Use of NUREG‐1400 is

inappropriate andtechnically not feasible since

the total absence of data

precludes a quantitative

assignment to the sourceterm that reflects residualcontamination.

Closed on July 31, 2012

Consideration of NUREG 1400 as a p

method for estimating residual conta

been deleted from OTIB‐0070, RevisiTable 5).
OTIB‐0070 Review Finding

# Finding Resolution

12 Use of Battelle‐TBD‐6000 for

assigning operational airconcentration values maynot be claimant favorable.

This finding is being addressed in Bat

6000, Issue 4 – July 26, 2010This finding will be closed when docufrom the TBD‐6000 Work Group is reindicating that TBD‐6000, Issue 4 has Closed.

13 It is not possible to judge

whether the basic approach

to developing inhalation

doses in TBD‐6001 is

claimant favorable.

Closed on July 31, 2012

Since TBD‐6001 has been cancelled, 

to and data from TBD‐6001 have beefrom OTIB‐0070, Revision 1.
OTIB‐0070 Review Finding

# Finding Resolution

14 Use of Battelle‐TBD‐6001 for

determining inhalationdoses may not be claimantfavorable.

Closed on July 31, 2012

Since TBD‐6001 has been cancelled, 

to and data from TBD‐6001 have bee

from OTIB‐0070, Revision 1.

15 Many of the assumptions

that form the basis of the

OCAS‐TIB‐009 ingestion

model are too restrictive

and may yield low ingestion

estimates.

Closed on February 5, 2013

Since Finding TIB‐009‐01 has been re

Closed, Finding OTIB‐0070‐15 has als

Closed.
Questions?