Philip Egidi US Environmental Protection Agency Office of Radiation and Indoor Air LowLevel Waste Forum Alexandria VA October 17 2017 Usual Disclaimers Apply This presentation is the opinion of the author only and does not represent EPA policy regulation or position ID: 658064
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Slide1
Existing Situations: Public Dose Limit and Optimization Through the Use of Reference Levels
Philip Egidi
U.S. Environmental Protection Agency
Office of Radiation and Indoor Air
Low-Level Waste Forum
Alexandria, VA
October 17, 2017Slide2
Usual Disclaimers Apply…
This presentation is the opinion of the author only and does not represent EPA policy, regulation, or position.
October 17, 2017
2Slide3
Premise
Radiation protection is based on fundamental principles, based on science, derived over many decades at the international level.
There are three basic principles that form the basis for regulation and control of radioactivity:
Limitation
Justification
Optimization
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October 17, 2017Slide4
Hierarchy of organizations:
Science forms the basis for recommendations
UNSCEAR
ICRP
IAEA
NAS
NCRP
ISCORSFEDERAL AGENCIESTRIBESCRCPDSTATES
COMPACTS
Source:
Lazo
2015/NEA
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October 17, 2017Slide5
Inter-Agency Steering Committee on Radiation Standards
Technical staff meet semi-annually (at least) with the purpose of harmonizing and being consistent among agencies in their approach to radiation protection
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October 17, 2017Slide6
Policy is Not Based on Science Alone
Source: Mossman 1999
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October 17, 2017Slide7
ICRP 103 Framework
“The Recommendations of the International Commission on Radiological Protection” ICRP Report 103
Published in 2007
Replaced Report 60, published in 1990
Replaced Report 26/30, published in 1977
Many US Regulations (e.g., NRC 10 CFR 20) based on ICRP 26/30 dosimetry
Some DOE and EPA criteria based on ICRP Report 60
New dose coefficients from ICRP 103 in process
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October 17, 2017Slide8
ICRP 103 changes
ICRP 60 (1990) based on activities that
increased
exposure (
practices
) and activities that
reduced
exposure (interventions)ICRP 103 (2007) based on
planned, existing and emergency situationsAll exposures, including those from (TE)NORM, are within the scope of the system.
The principles of
justification
and
optimization
apply universally to all exposures resulting from either planned, emergency or existing situations.
Limitation applies only to planned situations.
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October 17, 2017Slide9
Optimization
ICRP recommends
optimization
(ALARA) as the
primary tool
for radiation protection
Uses
dose constraints or reference levels set
within bands of doses Bands of dose are based on multiples of
1
mSv
(100 mrem)
, being the approximate level of annual global per caput radiation exposure from natural sources (excluding exposures from radon.)
Optimization applied below the upper limit of the band
Not an enforceable dose limit
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October 17, 2017Slide10
Planned and existing situations
ICRP 103 applies to all exposures to ionizing radiation from any source, regardless of size or origin.
For (TE)NORM, either the
source
of the exposure or the
pathways
leading to doses received by individuals can be
controlled by some
reasonable means, or Report 103 is not applicable. Planned situations, such as for licensed activities:
Use a
dose limit
Existing situations
, such as at NORM/TENORM industries:
Use a
reference level
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October 17, 2017Slide11
Source: Lecompte 2013
Existing Situations vs Planned Situations
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October 17, 2017Slide12
Existing Exposure Situations
A situation that already exists when a decision on control has to be taken, including natural background radiation and residues from past practices that were operated outside the Commission’s recommendations
NORM is an existing exposure situation (at least at first).
Reference level
In existing exposure situations, this represents the level of dose or risk, above which it is judged to be inappropriate to plan to allow exposures to occur, and below which optimization of protection should be implemented. The chosen value for a reference level will depend upon prevailing circumstances of the exposure under consideration.
NO DOSE LIMIT FOR EXISTING SITUATIONS…
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October 17, 2017Slide13
Reference Level Implementation
Reference levels for public exposure (as applies to TENORM)
Reference levels expressed in effective doses shall be set in the range of 1 to 20
mSv
(
100
mrem
to 2 rem) per year for existing exposure situations and 20 to 100 mSv
(2 to 10 rem)(acute or annual) for emergency exposure situations. …(b) a reference level below 1
mSv
(
100
mrem
) per year may be set, where appropriate, in an existing exposure situation for specific source-related exposures or pathways of exposure.
…The reference levels set shall take account of the features of prevailing situations as well as societal criteria… …for exposures below or equal to 1 mSv (
100
mrem
) per year, general information on the level of exposure, without specific consideration of individual exposures…
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October 17, 2017Slide14
ICRP 103 Dose limits
Public dose limit for planned situations is 1
mSv
/y above background
Effective dose
Exemption level for NORM isotopes:
1
kBq/kg (~27 pCi/g)Radon evaluated separately (ICRP 126, 2014)
There are other ICRP limits but will not discuss for brevity…
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October 17, 2017Slide15
ICRP Report 126 on Radon
The Commission recommends 300 Bq/m
3
(8 pCi/L) as the upper value of the derived reference level for radon gas in dwellings.
This equates to ~12mSv/y (1.2 rem)
Derived reference levels relate to the annual mean concentration of radon in a building or location
The Commission recommended a detriment-adjusted nominal risk coefficient for lung cancer in a mixed adult population of non-smokers and smokers of 8x10
-10 per Bq/h/m3 for exposure to radon-222 gas in equilibrium with its progeny [5x10
-4 per working level month (WLM)]. This is approximately twice the value used by the Commission in Publication 65
October 17, 2017
15Slide16
US Public Dose Limits
Presidential Radiation Protection Guidance for the Public (1960)
5
mSv
/y (500 mR/y) whole body
1.7
mSv
/y (170 mR/y) when source is not known50 mSv/30y (5 rem/30s) years to gonadsSpecific organ doses (1961)
NRC 10 CFR 20 1 mSv/y (100 mR
/y) effective dose from the licensed operation
EPA Indoor radon action level (recommendation) remains at 4 pCi/L
October 17, 2017
16Slide17
NCRP Report 116 (1993)
Public Dose Limits
1
mSv
/y (100 mR/y) effective dose continuous exposure5
mSv
/y (500
mR/y) effective dose infrequent exposure1.7 mSv/y (170 mR/y) when source is not knownRemedial Action Limits for NORM
2 WLM (7 x 10-
3
Jh
/
m
3)5 mSv/y (500 mrem/y)
NCRP is updating this report and new recommendations expected soon…
October 17, 2017
17Slide18
DOE Public dose limits
DOE Order 458.1 Ch 2 (2011)
1
mSv
/y (100 mR/y) effective dose15
mSv
/y (1.5 rem) lens of eye – equivalent dose
50 mSv/ ( 5 rem/y) skin and extremities – equivalent dose5 mSv (500 mrem) with approval providing does not exceed 1 mSv
/y averaged over 5 years.Includes TENORM from DOE operationsALARA appliesAdditional dose constraints…
October 17, 2017
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TENORM Is Not Regulated Like Other Radioactive Materials
ICRP Principles are not regulations. Each country adopts their own regulations based on ICRP.
ICRP basis for IAEA recommendations and standards.
Most US radiation regulations fall under the Atomic Energy Act of 1946, et seq.
TENORM however, is NOT captured by the Atomic Energy Act
This makes for an uneven playing field with respect to worker safety, public health and environmental protection
TENORM is mostly unintended and those who possess it often do not have the resources to properly manage it
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October 17, 2017Slide20
TENORM in the U.S.
It is unclear at this time how new dose coefficients and dose limits will impact the TENORM sector
No one agency regulates all public exposures, only those under their authority
The US will likely retain dose limits for all regulated activities
Emphasis will remain on Optimization (ALARA)
Radon remains a difficult challenge
States are primarily responsible for regulating TENORM
Public awareness is increasingICRP is not a regulatory body – these are principles that countries need to adopt into regulation.
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October 17, 2017Slide21
Summary
ICRP
is evaluating its approach to NORM/TENORM
TG-76 report in process, 2017-2018
Existing situations
may adopt reference bands
Optimization within bands
May result in relaxed radiation protection goals
Planned situation would have dose limits plus optimizationMany issues to address
No final decision anticipated soon
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October 17, 2017Slide22
Contact information
Philip Egidi
Environmental Scientist
Radiation Protection Division
Office of Radiation and Indoor Air
Washington, DC
202-343-9186
egidi.philip@epa.gov
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October 17, 2017