IAEA BSS WORKSHOP (2012):

DOSE LIMITS & DOSE CONSTRAINTS

Hairul Nizam Idris Malaysia

REGIONAL WORKSHOP ON THE

IAEA GENERAL SAFETY REQUIREMENTS: GSR PART 3

16 TO 20 APRIL 2012, KUALA LUMPUR

Main Topic

● Introduction

● Dose Limit

● Dose Constraint

● Gaps in Existing Guidance and Needs for Improving

● Summary

INTRODUCTION

• The publication GSR Part 3 is a revision of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (IAEA Safety Standards Series No. 115, Vienna, 1996)

• This presentation will cover aspect ‘Dose Limits And Dose Constraints’

• In Malaysia, aspect on ‘Dose Limit & Dose Constrain’ are cover under Atomic Energy Licensing (Basic Safety Radiation Protection) Regulations 2010 - P.U. (A) 46

• This regulation supersedes the previous regulation – i.e. Radiation Protection (Basic Safety Standard) Regulations 1988

DOSE LIMITS

Application

Dose Limit (mSv)

Effective dose - 20 mSv per year averaged over five consecutive years (100 mSv in 5 years), and

- 50 mSv in any single year

Lens of the eye - 20 mSv per year averaged over 5 consecutive years (100 mSv in 5 years), and

- 50 mSv in any single year

Extremities or Skin

500 mSv in a year.

Pregnant Female Worker/ Breast-feeding

- same broad level of protection as is required for members of the public

5

IAEA General Safety Requirements: GSR Part 3 - Schedule III (III-1: Dose limit for workers)

No. Dose Limit

Dose Limit (mSv)

in a calendar year

1. Effective dose

Note: With the condition the maximum effective

dose averaged over a period of 5 consecutive years

shall not exceed 20 mSv

20

2. Lens of the eye 150

3. Skin 500

4. Hands and feet 500

5. Foetus

Note: The foetus shall, from the date of the

confirmation, shall not exceed 1 mSv for the

remaining period of the pregnancy

1

7

Atomic Energy Licensing (Basic Safety Radiation Protection) Regulations 2010 - Reg. 8: Dose limit for worker

Application

Dose Limit (mSv)

Effective dose

1 mSv in a year

In special circumstances

-a higher value of effective dose in a single year could apply, provided that

the average effective dose over five consecutive years does not exceed 1 mSv per year

Lens of the eye

15 mSv in any single year

Skin

50 mSv in a year.

8

IAEA General Safety Requirements: GSR Part 3 - Schedule III (III-3: Dose limit for public exposure)

No. Dose Limit

Dose Limit (mSv)

in a calendar year

1. Member of Public 1

2. Lens of the eye 15

3. Skin 50

4. Knowingly assists in the support of patient

Note:

Shall not be allowed to continue when he received

the effective dose exceeding the limit of 5 mSv

unless have given strong clinical justification

5

5. Person < 16 years visiting patient undergoing

treatment and diagnostic examination involving RM

1

9

Atomic Energy Licensing (Basic Safety Radiation Protection) Regulations 2010 - Reg. 9: Dose limit for members of the public

Application

Dose Limit (mSv)

Effective dose - 6 mSv in a year

Lens of the eye

- 20 mSv in a year

Extremities or Skin

150 mSv in a year.

10

IAEA General Safety Requirements: GSR Part 3 - Schedule III (III-2: Dose limit for apprentices and students) apprentices between 16 and 18 years and students between 16 and 18 years

No. Dose Limit

Dose Limit (mSv)

in a calendar year

1. Effective dose

6

2. Equivalent dose - lens of the eye

50

3. Equivalent dose - hands and feet

150

4. Equivalent dose - skin

150

11

Atomic Energy Licensing (Basic Safety Radiation Protection) Regulations 2010 - Reg. 10: Dose limit for apprentices and students (apprentices between 16 and 18 years and students between 16 and 18 years)

DOSE CONSTRAINS

Dose constraints

• Dose constraints are applied to occupational exposure and to public exposure in planned exposure situations. Dose constraints are set separately for each source under control and they serve as boundary conditions in defining the range of options for the purposes of optimization.

• Dose constraints are not dose limits; exceeding a dose constraint does not represent non-compliance with regulatory requirements, but it could result in follow-up actions.

IAEA General Safety Requirements: GSR Part 3 - Dose constraints and Reference levels

Dose Constraint

a prospective restriction on dose, primarily intended to be used to discard undesirable options in an optimization calculation.

• Every licensee shall ensure that, except for medical exposure, the optimization of the protection and safety, shall-

Not exceed the DS or values which can the dose limits (DL) to be exceeded ;and

ensure that for any radiation source and radwaste management facility that can release radioactive material into the environment, the cumulative effects of each annual release from the radiation source are restricted so that the effective dose in any year to any member of the public, including people distant from the radiation source and people of future generations, is unlikely to exceed any relevant dose limit, taking into account the cumulative releases and the exposures expected to be delivered by all other relevant radiation sources and practices

Atomic Energy Licensing (Basic Safety Radiation Protection) Regulations 2010 - Reg. 7: Dose constraint (DS)

GAPS IN EXISTING GUIDANCE and NEEDS FOR IMPROVING

• Atomic Energy Licensing (Basic Safety Radiation Protection) Regulations 2010

o all dose limits (DL) and value are base on BSS 115 (1996) and ICRP 103

o Dose limit on the effective dose for a worker fix to 20mSv in a calendar year (in GSR Part 3 – 50mSv in any single year)

o Dose limit value for lens of the eye base on BSS 115 (1996)

o Not mentioned about DL for female workers who are breast-feeding

o not mentioned about ‘existing exposure situation’

o no statement / explanation about ‘Reference Level’

• Malaysia’s Atomic Energy Licensing (Basic Safety Radiation Protection) Regulations 2010 is released on 2010 and it developed base on old IAEA BSS 115 (1996) & ICRP 103

• So there is some gap with the IAEA revised BSS (2011)

• Malaysia government or regulatory body is unlikely to revise the regulation in the immediate future.

• Advice & recommendation from IAEA is needed to full fill the gaps

SUMMARY