1. Gauges and well logging
Potential exposure and radiation protection programme
Day 6 –Lecture 5

2. Objective
To discuss about potential for radiation exposure associated with nuclear gauges and well logging.
To discuss aim, structure and requirement of the Radiation Protection Programme (RPP) as applied to working with gauges and well logging
Lecture notes:
Instructions for the lecturer/trainer

3. Contents Pathways of Exposure Radiation Protection Programme (RPP)
Routine Exposure
Gamma Gauges
Beta Gauges
Neutron Gauges
Radiation Protection Programme (RPP)
Structure of RPP
Classification of Areas
Emergency Plans
Lecture notes:
Instructions for the lecturer/trainer

4. Pathways of exposure Internal Exposure External Exposure Ingestion
Absorption
Inhalation

5. Nuclear gauges and well logging Routine exposure
External doses
possible, although
unlikely to be significant
Internal doses
unlikely, due to sealed source construction
gamma and neutron sources special form
Lecture notes:
Instructions for the lecturer/trainer

6. Gamma gauges Typical external dose rate
111 GBq Cs-137
Contact dose rate
up to 75 Sv/h
Dose rate at 1m
1 Sv/h
Describe the scenario to the group:
Density gauge on a pipe - dose rate at the detector is 2 Sv/h.
Company fits a new gauge on an identical pipe on an identical plant.
- Source in the new gauge is 40 GBq Cs-137,
- What dose rate would you expect at the detector?
- A: expect 8 Sv/h,
- This would be have to be checked with a radiation monitor.
Delegates to attempt Question 1 (i to v)
Output data for Am-241 : 5.4 mSv/h at 1m per 400 GBq

7. Gamma gauges - routine exposure
Assume, for example, that employee spends 6 hours per year with hands in contact with gauge = 0.45 mSv annual extremity dose
Assume, for example, that employee spends 50 hours per year working 1 metre away from gauge = 0.05 mSv annual effective dose
Lecture notes:
Instructions for the lecturer/trainer

8. Gamma gauges - routine exposure
In reality, doses may be even lower than those indicated on the previous slide
Consider that most process control gauges (level gauges, density gauges etc) are sited in areas that are not usually occupied
Lecture notes:
Instructions for the lecturer/trainer

9. Beta gauges Typical external dose rate
3.7 GBq Pm-147
Shutter open (beta)
Dose rates will be higher for larger sources
Between guide plates
up to 10 Sv/h
Dose rate at 0.5m
<1 Sv/h
Describe the scenario to the group:
Density gauge on a pipe - dose rate at the detector is 2 Sv/h.
Company fits a new gauge on an identical pipe on an identical plant.
- Source in the new gauge is 40 GBq Cs-137,
- What dose rate would you expect at the detector?
- A: expect 8 Sv/h,
- This would be have to be checked with a radiation monitor.
Delegates to attempt Question 1 (i to v)
Output data for Am-241 : 5.4 mSv/h at 1m per 400 GBq

10. Beta gauges Typical external dose rate (worst case)
46 GBq Kr-85
Shutter closed (Bremsstrahlung)
Contact dose rate
up to 2 mSv/h
Dose rate at 1m
up to 10 Sv/h
Describe the scenario to the group:
Density gauge on a pipe - dose rate at the detector is 2 Sv/h.
Company fits a new gauge on an identical pipe on an identical plant.
- Source in the new gauge is 40 GBq Cs-137,
- What dose rate would you expect at the detector?
- A: expect 8 Sv/h,
- This would be have to be checked with a radiation monitor.
Delegates to attempt Question 1 (i to v)
Output data for Am-241 : 5.4 mSv/h at 1m per 400 GBq

11. Beta gauges - routine exposure
Assume, for example, that employee spends 6 hours per year cleaning gauge head (shutter closed), with hands in contact with gauge = 12 mSv annual extremity dose
Assume, for example, that employee spends 50 hours per year working 1 metre away from gauge (shutter closed) = 0.5 mSv annual effective dose
Lecture notes:
Instructions for the lecturer/trainer

12. Neutron gauges Typical external dose rate
1.85 GBq Am-241/Be
neutron and gamma dose rate
Contact dose rate
up to 30 Sv/h
(source retracted)
Operator position
during use up to
15 Sv/h
Describe the scenario to the group:
Density gauge on a pipe - dose rate at the detector is 2 Sv/h.
Company fits a new gauge on an identical pipe on an identical plant.
- Source in the new gauge is 40 GBq Cs-137,
- What dose rate would you expect at the detector?
- A: expect 8 Sv/h,
- This would be have to be checked with a radiation monitor.
Delegates to attempt Question 1 (i to v)
Output data for Am-241 : 5.4 mSv/h at 1m per 400 GBq

13. Neutron gauges - routine exposure
Assume, for example, that employee spends 50 hours per year with hands in contact with gauge (source retracted) = 1.5 mSv annual extremity dose
Assume, for example, that employee spends 250 hours per year using the gauge = 3.75 mSv annual effective dose
Lecture notes:
Instructions for the lecturer/trainer

14. Well logging Typical external dose rate
37 GBq Am-241/Be
neutron and gamma dose rate
10 cm from tool
up to 2.1 mSv/h
Surface of source
transport container
up to 150 Sv/h
Describe the scenario to the group:
Density gauge on a pipe - dose rate at the detector is 2 Sv/h.
Company fits a new gauge on an identical pipe on an identical plant.
- Source in the new gauge is 40 GBq Cs-137,
- What dose rate would you expect at the detector?
- A: expect 8 Sv/h,
- This would be have to be checked with a radiation monitor.
Delegates to attempt Question 1 (i to v)
Output data for Am-241 : 5.4 mSv/h at 1m per 400 GBq

15. Well logging - routine exposure
Time with source exposed likely to be only a few seconds per operation. Assume, for example, that employee spends 8 hours per year with hands at 10 cm from exposed source = 16.8 mSv annual extremity dose
Assume, for example, that employee spends 50 hours per year close to transport container = 7.5 mSv annual effective dose
Lecture notes:
Instructions for the lecturer/trainer

16. Radiation Protection Programme
What is an RPP?
Structure of the RPP
Assignment of responsibilities
Role of the Qualified Expert
Classification of areas
Local rules and supervision (RPO)
Radiation monitoring
Record Keeping
Emergency plans
Audit and review
Lecture notes:
Instructions for the lecturer/trainer

17. What is an RPP?
A programme that reflects the application of management responsibility for radiation protection and safety
Key factor for the development of a safety culture
Effectiveness depends on management commitment
Essential to undertake a prior radiological evaluation and safety assessment before developing the RPP

18. Structure of the RPP assignment of responsibilities
classification of areas
local rules
supervision arrangements, including RPO appointment
arrangements for area monitoring
arrangements for individual monitoring

19. Qualified Experts to provide advice on contents of RPP
Structure of the RPP
record keeping
education, information and training
emergency plans
health Surveillance
quality Assurance
reviewing/ auditing the RRP
Qualified Experts to provide advice on contents of RPP

20. Radiation Protection Responsibilities
Management
Obtain necessary authorizations
Provide necessary facilities, personnel, equipment and training
establish and maintain a “safety first” culture
Radiation Protection Officer (RPO)
Implement the RPP
Implement the local rules
Provide information and training

21. Radiation Protection Responsibilities
Operators and Workers
Become familiar with equipment, safety and warning systems
Become familiar with any local rules and adhere to them
Notify the RPO of any unusual occurrences
Use all safety equipment provided
Clients
Provide a safe working environment and adequate time for the job

22. Role of the Qualified Expert
Provides advice on observance of the BSS
Registrants/licensees to identify suitable Qualified Expert(s)
Registrants/licensees to inform the Regulatory Authority of their arrangement with Qualified Expert

23. Classification of Areas
A controlled area is an area where procedural controls are required in order to restrict radiation exposures
A supervised area is one that does not require classification as a controlled area, but where exposure conditions should be kept under review.
Primary mechanism for restricting radiation doses is the control of access to areas where there is a potential for significant exposure.
IAEA BSS defines two types of radiation areas : controlled and supervised areas.
Need to classify determined by means of a prior safety assessment.
Controlled areas : where specific protective measures/safety provisions required for controlling normal exposures and/or prevention or limiting the extent od any potential exposures

24. Controlled areas
Examples of controlled areas associated with nuclear gauges are:
around portable gauges (eg soil moisture probes and nuclear density gauges) during use and transport
inside portable source stores
around fixed gauges during some maintenance operations
inside vessels on which level gauges are fitted
Primary mechanism for restricting radiation doses is the control of access to areas where there is a potential for significant exposure.
IAEA BSS defines two types of radiation areas : controlled and supervised areas.
Need to classify determined by means of a prior safety assessment.
Controlled areas : where specific protective measures/safety provisions required for controlling normal exposures and/or prevention or limiting the extent od any potential exposures

25. Controlled areas
Examples of controlled areas associated with well logging are:
around the borehole head during use
inside the source store
around the logging tool during source loading operations
around the source containers during transport of equipment
Primary mechanism for restricting radiation doses is the control of access to areas where there is a potential for significant exposure.
IAEA BSS defines two types of radiation areas : controlled and supervised areas.
Need to classify determined by means of a prior safety assessment.
Controlled areas : where specific protective measures/safety provisions required for controlling normal exposures and/or prevention or limiting the extent od any potential exposures

26. Controlled Area Requirements
Demarcation
Restriction of access
Signs
Monitoring
Local rules
Controlled areas must be physically delineated - including physica boundaries/signs/notices at all access points clearly stating that the area is controlled
For enclosures the walls, doors and roof will form the boundary.
Site radiography - temporary barriers to be erected to form the boundary and natural boundaries may be used (walls/fences).
The area may extend in the vertical plane!

27. Local Rules
Work in a controlled area must be carried out in accordance with written local rules,
Local rules should include:
name of person(s) responsible for supervising the work
description of controlled and supervised areas
general radiation safety measures
dose investigation levels
emergency plans
Local rules ; describe organisational structure, procedures to be followed in the controlled area.

28. Supervised areas
Examples of supervised areas associated with nuclear gauges are:
around fixed gauges (gamma and beta)
Primary mechanism for restricting radiation doses is the control of access to areas where there is a potential for significant exposure.
IAEA BSS defines two types of radiation areas : controlled and supervised areas.
Need to classify determined by means of a prior safety assessment.
Controlled areas : where specific protective measures/safety provisions required for controlling normal exposures and/or prevention or limiting the extent od any potential exposures

29. Supervised Area Requirements
Delineation
Signs
Monitoring
Controlled areas must be physically delineated - including physica boundaries/signs/notices at all access points clearly stating that the area is controlled
For enclosures the walls, doors and roof will form the boundary.
Site radiography - temporary barriers to be erected to form the boundary and natural boundaries may be used (walls/fences).
The area may extend in the vertical plane!

30. Supervision Radiation Protection Officer (RPO) supervises the work
Ensures any local rules are followed
Should be enough RPOs to ensure adequate supervision at all times
Supervision :
Regulatory Authorities often require that the employer appoints one (or more) RPOs to supervisie work (to confirm that local rules are complied with etc)
RPOs Primary role :
liase with radiographers and management
be able to recognise need to seek further advise
supervise radiation protection aspects of work
RPOs should be someone :
in line management position and involved with the work 9on a day to day basis)
be familiar with the work
who has received sufficient raining (radiation protection and safety)

31. Area Monitoring
Monitoring of radiation dose rate required for all controlled and supervised areas
Records of monitoring should be kept
Purpose of monitoring is to ensure that radiation levels remain within expected limits
Good idea to set action levels above which steps are taken to reduce the radiation dose rate
Local rules :
set of instructions that specify the manner in which work should be carried out to ensure adequate levels of protection & safety for worker/others
reflect practical requirements of national legislation
employer is responsible for issue

32. Individual monitoring
Required for all those who access controlled areas
May require assessment of gamma and neutron dose
Records of individual monitoring must be kept
Purpose of monitoring is to demonstrate that exposures are adequately controlled
Investigation level must be set
Local rules :
set of instructions that specify the manner in which work should be carried out to ensure adequate levels of protection & safety for worker/others
reflect practical requirements of national legislation
employer is responsible for issue

33. Individual dose meters
TLD - gamma, X, neutron and beta
Film - gamma, X and beta
OSL - gamma, X, neutron and beta
PADC - neutron
Consult Qualified Expert regarding type of dosemeter and wear period

34. Record keeping Source accountancy Dose rate monitoring results
updated frequently for portable gauges
Dose rate monitoring results
Checks on safety systems and warning devices
Equipment maintenance
Source leak test certificates
Radiation monitoring instrument test certificate
Local rules :
set of instructions that specify the manner in which work should be carried out to ensure adequate levels of protection & safety for worker/others
reflect practical requirements of national legislation
employer is responsible for issue

35. Education, information and training
Training of RPO
Radiation awareness training for other staff
nature of the hazard
extent of any controlled or supervised areas
requirements of local rules
emergency plans
Local rules :
set of instructions that specify the manner in which work should be carried out to ensure adequate levels of protection & safety for worker/others
reflect practical requirements of national legislation
employer is responsible for issue

36. Emergency plans Consider reasonably foreseeable accidents
Provide instruction to limit the consequences
Rehearse periodically
Local rules :
set of instructions that specify the manner in which work should be carried out to ensure adequate levels of protection & safety for worker/others
reflect practical requirements of national legislation
employer is responsible for issue

37. Protection of the public
Emergency plans to consider possible accidents involving the public, eg loss or theft of a source
necessary precautions
actions to limit consequences
liaison with Emergency Services

38. Audits and Reviews
Aim : To enhance the effectiveness and efficiency of the RPP
Objectives :To identify and correct problems that may prevent the achievement of the programme's objectives
Conducted by competent persons
Local rules :
set of instructions that specify the manner in which work should be carried out to ensure adequate levels of protection & safety for worker/others
reflect practical requirements of national legislation
employer is responsible for issue

39. Summary
Potential for radiation exposure associated with nuclear gauges and well logging
routine use
accidents
Aim, structure and Requirement of the RPP as applied to working with gauges and well logging
Any questions or comments?
Lecture notes:
Instructions for the lecturer/trainer