CSP9
Version 1.2
ISSN 0110-9316CODE OF SAFE PRACTICE FOR THE USE OF
X-RAYS AND RADIOACTIVE MATERIAL IN INDUSTRIAL RADIOGRAPHY
Office of Radiation Safety
Ministry of Health
P O Box 3877
Christchurch 8140
New Zealand
March 1997
Revised June 2010
© 1997, Office of Radiation Safety
Ministry of Health
Published with the permission of the Director-General of Health
TABLE OF CONTENTS
1 INTRODUCTION
2 ORGANISATION AND ADMINISTRATION OF
RADIATION PROTECTION
2.1 Introduction
2.2 Radiation protection legislation
2.3 Basic principles of radiation protection practice
2.4 Obligations of industrial radiography companies and owners
of industrial radiography X and gamma ray equipment
2.5 Obligations of the licensee 7
2.6 Personal monitoring 8
2.7 Individual dose limits
2.8 Radiation dose records 9
2.9 Investigation and notification of exposures 10
2.10 Control of radioactive material 11
3 EQUIPMENT
3.1 Introduction
3.2 X-ray equipment
3.3 Gamma ray equipment
3.4 Pipeline crawlers 16
3.5 Safety equipment
4 REQUIREMENTS FOR AN IN-HOUSE RADIOGRAPHY OPERATION
4.1 Introduction
4.2 General requirements
5 REQUIREMENTS FOR SITE RADIOGRAPHY
5.1 Introduction
5.2 General requirements
6 GENERAL WORKING PROCEDURES
7 EMERGENCY PROCEDURES
7.1 Introduction
7.2 Emergency recognition
7.3 X-ray emergencies
7.4 Gamma equipment emergencies
8 TRANSPORT
BIBLIOGRAPHY 27
APPENDIX A 29
GLOSSARY 30
1 INTRODUCTION
1.1 This Code of Practice relates to the use of x-rays and radioactive material for the purpose of industrial radiography and covers both site and in-house work.
1.2 This Code should be read in conjunction with the Radiation Protection Act 1965 and the Radiation Protection Regulations 1982. It is intended as a guide to safe practice and should be applied with sound judgement to any specific situation.
1.3 A copy of this Code is provided to all licensees in industrial radiography. Additional copies are available on request. Each licensee shall provide free and convenient access to this Code to all personnel working under his/her supervision.
1.4 Whenever compliance with a requirement in this document is required as a condition to a licence under the Radiation Protection Act 1965, the word “shall” is used in the clause. The word “should” indicates a practice that is recommended but not mandatory. Clauses without either of these words are for information and do not imply obligation for compliance with this Code.
1.5 SI units are used in this Code. Conversion factors to convert from and to the previous units are given in Appendix A.
2 ORGANISATION AND ADMINISTRATION OF RADIATION PROTECTION
2.1 Introduction
This section is primarily based on the statutory requirements of the Radiation Protection Act 1965 and the Radiation Protection Regulations 1982. The Regulations apply to any x-ray equipment that produces a dose equivalent rate of or exceeding 2.5 microsieverts per hour (mSv h-1) at a point which could be reached by a human being and radioactive material with an activity exceeding 3kilobecquerels (kBq). Any industrial x-ray or gamma-ray equipment is therefore subject to the Regulations.
2.2 Radiation protection legislation
The legislation under which this Code is written, is:
The Radiation Protection Act 1965
The Radiation Protection Regulations 1982.
The Act and Regulations may be amended or replaced before this Code is next revised. If so then references to legislation in the Code shall be deemed to refer to the current legislation. In the event of contradiction between the Code and revised legislation, the requirements of the legislation shall be paramount.
It must be noted that this Code deals with the requirements of radiation protection legislation only. Other legislation covering occupational safety, protection of the environment, local body planning, transport and other issues may overlap with the radiation protection legislation in some respects, and may impose additional requirements. Compliance with this Code in no way implies that all or any of these other requirements have been satisfied.
2.2.1 The Radiation Protection Act 1965 and amendments and its Regulations 1982 govern the safe use of irradiating apparatus (ie, x-ray equipment) and radioactive material in New Zealand. The Act is administered in the Ministry of Health by the Office of Radiation Safety.
2.2.2 The following points arising from the Act and Regulations are noted but the reading of these is neither intended as a substitute for reading of the Act and Regulations themselves nor is it an exhaustive coverage of points of interest for users of industrial radiography apparatus. Copies of the Act and relevant Regulations together with any codes of safe practice (such as this one) are required to be made readily available to industrial radiography personnel by the licensee in any establishment.
2.2.3 No person shall use industrial radiography X or gamma equipment unless he/she is the holder of a licence under the Act, or is acting under the supervision or instructions of a licensee (Sections 13 and 15 of the Act). In any company, having a number of licensees may lead to misunderstandings in authority or responsibility. Provision is made in the Regulations for nominating one of the licensees as principal licensee to supervise compliance by the whole group. This is not practical, however, if licensees are working at widely scattered locations.
2.2.4 Licences are issued subject to any conditions that may be prescribed in respect of licences generally as well as those explicit in the Act. Individual licences may additionally be subject to conditions such as restriction to a specified x-ray machine or to specified premises.
2.2.5 Prospective licensees should have at least 6 months’ work experience and shall demonstrate by way of a three hour examination conducted by the Office of Radiation Safety an appreciation of
(1) The hazards associated with the use of ionising radiation.
(2) The responsibilities of an industrial radiography licensee.
(3) Safe working practices.
(4) The procedures to be followed in an emergency.
(5) The ability to calculate doses and dose rates, under typical industrial radiography conditions, eg, be able to submit a design and safety assessment of an exposure cell.
(6) The Act and Regulations (including requirements for the transport of radioactive materials).
2.2.6 Professional degree courses or the holding of a licence from other recognised authorities may be adduced as appropriate evidence of such appreciation.
2.2.7 The granting of a licence places full legal responsibility for the safe use of x-ray equipment and/or radioactive material on the licensee.
The following conditions are placed on licences for industrial radiography:
(1) The use of radioactive materials is restricted to sealed materials in approved exposure devices.
(2) Radioactive material and x-ray machines for industrial radiography shall be used in accordance with the CSP9.
2.3 Basic principles of radiation protection practice
The New Zealand radiation protection legislation is based on the following five principles, set down by the International Commission on Radiological Protection in ICRP publication 605:
(1) No practice shall be adopted unless its introduction produces a positive net benefit to the exposed individuals or to society to offset the radiation detriment it causes. (Justification of the practice.)
(2) In relation to a particular practice, the magnitude of individual doses, the number of people exposed and the likelihood of incurring exposure where these are not certain to be received shall all be kept as low as reasonably achievable (ALARA), economic and social factors being taken into account. This procedure shall be constrained by restrictions on the doses to individuals (dose constraints), or the risks to individuals in the case of potential exposures (risks constraints), so as to limit the inequity likely to result from the inherent economic and social judgements. (Optimisation of protection.)
(3) The exposure of individuals resulting from the combination of all the relevant practices shall be subject to dose limits, or to some control of risk in the case of potential exposures. These are aimed at ensuring that no individual is exposed to radiation risks that are judged to be unacceptable from these practices in any normal circumstances. Not all sources are susceptible of control by action at the source and it is necessary to specify the sources to be included as relevant before selecting a dose limit. (Limitation of individual dose and risk.)
The two principles in the case of interventions are
(1) The proposed intervention should do more good than harm, ie, the reduction in detriment resulting from the reduction in dose shall be sufficient to justify the harm and the costs, including social costs, of the intervention.
(2) The form, scale, and duration of the intervention should be optimised so that the net benefit of the reduction of dose, ie, the benefit of the reduction in radiation detriment, less the detriment associated with the intervention, shall be maximised.
2.4 Obligations of industrial radiography companies and owners of industrial radiography X and gamma ray equipment
The ALARA principle requires that owners of industrial radiography X and gamma ray equipment take all reasonable practical steps to restrict the extent to which all persons are exposed to ionising radiation. To that end the owners shall ensure that there is a suitably licensed person (see 2.2.3) responsible for the safe care of the radioactive material and/or x-ray equipment.
The owner shall provide adequate equipment, materials, and manpower to ensure the use, transportation, storage and disposal of radioactive material and/or x-ray equipment is carried out safely at all times.
If there is no suitable licensed person the radioactive material and x-ray equipment shall not be used. They shall be stored to the satisfaction of the Office of Radiation Safety or disposed of in accordance with the Regulations.
2.4.1 Contract notification
Prior to the commencement of any industrial radiography contract involving site radiography that is expected to last for at least 4 months, the principal licensee involved shall inform ORS of the contract, giving details of the following:
(1) Location of contract.
(2) Proposed starting date.
(3) Proposed completion date.
(4) Licence holders undertaking the contract.
(5) Equipment to be used.
2.4.2 Education and training of radiation workers
2.4.2.1 General requirement
Persons engaged in industrial radiography shall be educated and trained appropriately for the work so that they may use ionising radiations efficiently and safely. They shall be fully conversant with the hazards of ionising radiations, and the working procedures and emergency procedures adopted by the Company (see sections 6 and 7).
2.4.2.2 Continuing education
Industrial radiographers should endeavour to keep abreast of technical improvements, especially those which affect the efficiency of use of radiation or radiation safety. Appropriate advanced courses, refresher courses, and seminars, should be attended.
2.5 Obligations of the licensee
2.5.1 Every licensee is responsible for the safe care of any radioactive material or x-ray equipment under his/her control and shall retain that responsibility until it is assumed by another suitably licensed person or the radioactive material or x-ray equipment is stored or disposed of according to the Regulations.
2.5.2 Every licensee shall ensure that every person using the radioactive material or x-ray equipment under his/her control complies with the provisions of the Regulations and to any further conditions of the licence.
2.5.3 Every licensee shall ensure that every person working with radioactive material or x-ray equipment under that licence has been fully instructed in the hazards of ionising radiation associated with the equipment and is fully conversant with the company’s working procedures and emergency procedures in the event of an incident. (Note that this precludes the practice of using a licensed radiographer assisted by someone from the shop floor with no background in radiation protection.)
2.5.4 The licensee shall ensure that all the necessary safety equipment is on hand and is being used correctly to comply with the Regulations.
2.5.5 The licensee shall ensure all practical steps are taken to prevent unauthorised tampering with the industrial radiography apparatus under the licensee’s control.
2.5.6 The licensee shall take all practical steps to prevent the loss of industrial radiography apparatus under his/her control.
2.5.7 The licensee shall in the event of the loss of radioactive material take all reasonable steps to recover that radioactive material, and to estimate the dose equivalent that any person might receive as a consequence of that loss. The licensee shall inform the Office of Radiation Safety as soon as practicable of that loss and the course of action taken.
Refer to 2.8 for action following the overexposure of any person.
2.6 Personal monitoring
2.6.1 The Regulations require that all personnel working in conditions where the annual dose from ionising radiation might exceed three-tenths of the effective dose limit be subject to individual monitoring.
For the purpose of this Code it will be deemed that all persons actively engaged in industrial radiography fall in the above category and shall be continuously monitored by a dosemeter of a type approved by the Office of Radiation Safety.
2.6.2 Film monitors are available from the National Radiation Laboratory. Films are changed at monthly intervals. The use of old films and the wearing of films for longer than one month result in a significant loss of sensitivity and accuracy in the measurement of personal dose. Regardless of any reduction in workload, the film in each monitor must be returned to the National Radiation Laboratory not more than one month after issue, and replaced with a newly issued film, to ensure reliable measurements.
2.6.3 Other personal monitors that record accumulated dose may be used if approved by the Office of Radiation Safety. These are to be calibrated annually.
2.6.4 Standard wearing position for personal dosemeters is at waist level.
2.7 Individual dose limits
For the purpose of this Code of Safe Practice the radiation dose limits are:
2.7.1 Limits for persons exposed to radiation as a normal condition of employment
(1) an effective dose of 20 mSv per year averaged over any five-year period and 50 mSv in any one year;
(2) an equivalent dose of 500 mSv to the skin at the nominal depth of 7mgcm-2 averaged over 1 cm2, regardless of the total area exposed, in any one year;
(3) an equivalent dose of 150 mSv to the lens of either eye in any one year;
(4) an equivalent dose of 500 mSv to the hands and feet in any one year;
(5) for women who declare themselves pregnant an equivalent dose of 2mSv at the surface of the abdomen over the remainder of the pregnancy.