輻射防護新趨勢研討會 Introduction to Draft 2005 Recommendations from ICRP Ching-Pang Lu...

輻射防護新趨勢研討會

Introduction to Draft 2005 Recommendations from ICRP

Ching-Pang LuKuosheng Nuclear Power Plant, Taiwan Power Compa

ny18/10/2004

email: [email protected]

輻射防護新趨勢研討會2

‧Recommendations of ICXRP(1928 －1950)

‧ICRP-1 （ 1959 ） ‧ICRP-6 （ 1964 ） ‧ICRP-9 （ 1966 ） ‧ICRP-26 （ 1977 ） ‧ICRP-60 （ 1991 ） ‧ICRP- ？？（ 2005 ）

History of the ICRP ecommendations


The 1990 system of protection, set out in Publication 60 (ICRP 1991), was developed over some 30 y. During this period, the system became increasingly complex as the Commission sought to reflect the many situations to which the system applied . － Roger H. Clarke (Health Phys. 87(3):306 –311; 2004 )

ICRP-60 回顧（ A review of ICRP-60 ）


Major reasons for the change of the recommendations addressed by

ICRPThe complexity of ICRP-60 is logical but not easy to explain the variations between different applications .Confusion between dose limits and action levels.

The concept of “constraint” has not been clearly explained.

The cost-benefit analysis procedures for ALARA and optimization (ICRP-37 ＆ 55) have been never adopted.

The misuse of collective dose － widely used over world population and all time.LNT controversy and confusion.The new biological data.


Development of the new ICRP recommendations － essential milestones19981999200020012002200320042005

Critical review on current system by Clarke （HPS ）Initial proposal promulgated through IRPA and JRP for discussion.

Comments from IRPA-10 /Began to develop the new recommendations.

Continual debates with iteration of ideas at the international forums or workshops held by OECD/NEA, etc.

Presentation at IRPA-11/Draft text of the 2005 ICRP recommendations for consultation.

The new recommendations will be issued.


Main features of the new recommendations

Complementing the constraints and limits with the requirements for the optimization of protection from a source.

The need for stability in international and national regulations has been taken into account.Reflecting both the scientific understanding of the biological effects and the social and ethical standards.Simpler approach based on “individual oriented” philosophy rather than current “society oriented” criteria.

Emphasizing that procedure of diagnostic or therapeutic should be justified with clinical benefit for the patient dose.Incorporating a policy for radiological protection for non-human species in the new system.

Quantifying the most basic level of protection from single source in all situations － Maximum dose constraints.


Essential changes in the new recommendations（ Summarized by Roger H. Clarke, 2004 ）

Linearity Current

Clarify concept and applicable range, i.e., above a few mSv /y

New

Linear non-threshold, i.e., proportionality

The LNT controversy: Academically interesting but practically meaningless!!

Abel J. González


低劑量下的劑量回應關係（ The dose-response relationship at low-doses ）資料來源； Abel J. González, Radiation safety and their application: International policies and current issues, Health Physics: Volume 87(3) September 2004 p262.

△△DD1 ＝ △＝ △ DD2

△△pp1 ＝ △＝ △ pp2


Essential changes in the new recommendations（ summarized by Roger H. Clarke, 2004 ）

Radiation weighting factor New

ICRP-60 Revised values for protons and neutrons(ICRP-92)

Current



Tissue weighting factor New

ICRP-60 New values based on revised risk factors and a simplified basis/individual organs changed

Current



Nominal risk coefficient Current

ICRP-60 Risk coefficients for Total cancer fatality slightly modified /Hereditary use UNSCEAR (2001)

New


May be typing error


Don’t use Nominal risk coefficient or effective dose for:

－ Estimating risks retrospectively for individuals.－ Epidemiological purposes with populations.

Caveat on effective dose and nominal risk coefficients



Dose limits Current

Worker and public in ICRP-60

Incorporated into revised constraints /only applied to all sources in normal situation.

New



Constraints Current

30 numerical values for constraint in the 10 ICRP reports, level of concern Effective dose

Number and complexity to be reduced

New


‧Factor influencing the choice of individual dose constraints

Major Concepts of the new ICRP recommendations

Annual effective dose from natural radiation sources

1msv/a to which rounded from 1.2msv with a range 0.8 to 2.4msv quoted in UNSCEAR 2000 by ICRP

Excluding radon

The need for action vs. individual effective dose


Recommended maximum values for dose constraints on single sources

100Emergencies, evacuations, no justification above

20 Some benefits to exposed individuals

1Societal rather than individual benefit0.01

Minimum value

Incremental dosemSv in a year

Natural background~ (1 mSv/a)

from : Richard V. Osborne, 2004


INDIVIDUAL- AND SOURCE-RELATED INDIVIDUAL- AND SOURCE-RELATED CONCEPTSCONCEPTS資料來源：資料來源： Ches MasonChes Mason, , International Conference on National Infrastructures for Radiation SafetyRabat, Morocco 1-5 September 2003

INDIVIDUALS ARE PROTECTEDINDIVIDUALS ARE PROTECTEDFROMFROM ALLALL REGULATED REGULATED SOURCESSOURCESBY THEBY THE DOSE LIMITSDOSE LIMITS

INDIVIDUALS ARE PROTECTEDINDIVIDUALS ARE PROTECTEDFROM AFROM A SINGLESINGLE SOURCESOURCEBY THEBY THE DOSE CONSTRAINTDOSE CONSTRAINT


Dose Limit



Dose Constraint




Collective dose Current

ICRP-60 Disaggregated and replaced by weighted dose matrix

New



Justification Current

Retained, extended for patient exposure

New

ICRP-60



Optimization Current

Stakeholder involvement

New

Cost-benefit analysis


‧ Stakeholder involvement

Major Concepts of the new ICRP recommendations

One of the major achievements of ICRP for developing the new recommendations is the role that is now recognized to “stakeholder involvement” in the optimization process as a mean to improve the quality of the decision aiding process for identifying and selecting protection actions considered as being accepted by all those involved.


Roger Clarke noted that cultural differences make it difficult for stakeholders from different parts of the world to participate equally in developing international regulatory guidance such as that offered by ICRP.



ExemptionCurrent

ICRP-60

New

Replaced by exclusion


Exclusion



Definition of ‘individual’ Current

New

ICRP-29New consideration

age-weighted approachCharacterising the individual

Time frames and spatial distributions

Uncertainty



PracticeCurrent

New

ICRP-60 Retained



InterventionCurrent

New

ICRP-60 Incorporated into constraints



Natural radiation sources Curren

tNew

Radon-222 only Comprehensive treatment



Environment (nonhuman) Curre

nt

Assumed protected in ICRP-60

New

Explicitly addressed


人類與其他物種輻射防護系統共同架構示意圖（ Developing a common approach for the radiological protection of humans and non-human organisms ）資料來源： Annals of ICRP Volume 33, issue 3, A framework for assessing the impact of ionising radiation on non-human species, ICRP Publication 91, September 2003, p.254.


References 1.ICRP, 1990 Recommendations of the International Co

mmission on Radiological Protection. ICRP Publication 60. Annals of the ICRP 21 (1-3), Pergamon Press, 1991.

2.Summary excerpted from the draft ICRP Recommendations that will be subjected to public consultation from June 2004.

3.IRPA 11Daily Newsletter 25th of May 2004.4.The Future Policy for the Radiological Protection Wor

kshop Proceedings, OECD/NEA, Lanzarote, Spain, 2-4 April, 2003.

5.ICRP Publication 91, A framework for assessing the impact of ionising radiation on non-human species , Annals of the ICRP Volume 33, Issue 3, Pergamon Press, 2003 .


References

6.ICRP Publication 92, Relative biological effectiveness (RBE), quality factor (Q), and radiation weighting factor ( wR ), Annals of the ICRP Volume 33, Issue 4, Pergamon Press, Oxford, UK, 2003

7.2005 Recommendations of the International Commission on Radiological Protection (Draft for Consultation), 21 June 2004.

8.Abel J. González, Radiation safety and their application: International policies and current issues, Health Physics: Volume 87(3) September 2004.

9.Ches Mason, International Conference on National Infrastructures for Radiation Safety Rabat, Morocco 1-5 September 2003, IAEA.


References

10.Roger H. Clarke , Draft recommendations from ICRP at the start of the 21ST century, , Health Physics: Volume 87(3) September 2004.

11.Richard V. Osborne, Are the Proposed Recommendations of the International Commission on Radiological Protection Taking Us in the Right Direction? Robert S. Landauer, Sr. Lecture, 49th Annual Meeting of the Health Physics Society, Washington, DC, 2004 July 11-15.

12.Stakeholder Participation in Radiological Decision Making- Processes and Implications-Third Villigen Workshop , OECD/NEA, Villigen, Switzerland - 21-23 October 2003.

輻射防護新趨勢研討會 Introduction to Draft 2005 Recommendations from ICRP Ching-Pang Lu...

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