Inspection report: ARPANSA Medical Radiation Science Branch (MRSB), Yallambie, Victoria (R21/09554)

An inspection was conducted as part of ARPANSA’s baseline inspection program to assess compliance with the Australian Radiation Protection and Nuclear Safety Act 1998 (the Act), the Australian Radiation Protection and Nuclear Safety Regulations 2018 (the Regulations), and conditions of facility licence F0046.

The scope of the inspection included an assessment of ARPANSA’s Medical Radiation Science Branch’s (MRSB) performance against the Performance Objectives and Criteria (POC). The inspection consisted of a review of records, interviews, and due to the current COVID-19 pandemic was conducted via virtual means.

An inspector from the Tasmanian radiation regulatory authority (Department of Health) participated in the inspection to provide additional independence. The Tasmanian officer has also reviewed and agreed the content and conclusions of this inspection report.

Background

ARPANSA MRSB is authorised to operate linear accelerators (linacs) and a teletherapy laboratory. MRSB currently operates two linacs, which provide photon and electron beams. The teletherapy laboratory includes a Co-60 source and a Cs-137 source. The linacs and teletherapy laboratory are used to maintain primary standards and provide calibration services.

The main codes and standards applicable to this licence are those that appear in section 59 of the Regulations plus:

1. Australian/New Zealand Standard: Safety in laboratories Part 4: Ionizing radiations (AS/NZS 2243.4:2018)
2. Radiation Health Series 24: Code of Practice for the Design and Safe Operation of Non-medical Irradiation Facilities (1988) (RHS 24).
3. Health Physics Society (HPS) Installations using non-medical x-ray and sealed gamma-ray sources, energies up to 10 MeV (ANSI/HPS N43.3-2008).

Observations

Given the COVID-19 situation in Australia, travel between states is currently not allowed. As such, in order to ensure ARPANSA’s compliance program is unaffected, the inspection was conducted virtually. It was positive to note that the licence holder supplied a large number of documents electronically to support the inspection.

As a result of the inspection, a non-compliance was identified along with 4 areas for improvement (AFI). While the non-compliance and the majority of the AFI are singular issues, a broad AFI has been included to demonstrate a systemic issue within MRSB’s documentation management.

Performance reporting and verification

ARPANSA inspectors sought evidence of the actions taken to address the findings from the previous inspection in 2019. In response to non-compliances, MRSB undertook a self-assessment against applicable codes and standards (i.e. RHS-24 and AS 2243.4) applying a graded approach as they are not specific to the licence holder’s facility but can be applied more broadly. This had been provided to Regulatory Services Branch (RSB) to demonstrate the non-compliances had been rectified. The inspectors verified that associated actions were complete. Also, the plans and arrangements have since been reviewed in-line with the regulatory requirement. All AFI have been actioned.

Between inspections, MRSB has also developed a safety analysis report (SAR) for its teletherapy facility and updated their SAR for the linacs. However, these do not fully describe the facilities i.e. the teletherapy and linac SARs focus mainly on the Co-60 source and the Elekta Versa HD linac respectively. The documents do not describe the Cs-137 source and Elekta Synergy linac. ARPANSA inspectors highlighted that both documents should be further updated to ensure that the living document captures the facilities in their entirety. This is considered an area for improvement.

A week prior to the inspection, MRSB reported to RSB that there may have been a potential breach of section 63 of the Regulations. This will be discussed in the section below. However, it is positive to note that this potential breach has been self-reported in line with the requirements of section 57 of the Regulations.

No radiation safety related events have occurred at either facility.

Configuration management

MRSB employs the use of a Hazard Identification, Risk Assessment and Management (HIRAMs) document to their risk assessments i.e., identifying hazards, implementing controls, calculating risk. The WHS Management Manual (ARPANSA-FRM-0007) requires the HIRAMs to be initially reviewed and signed off by the appropriate staff (Health & Safety Representative’s, Section Managers, Branch Heads, WHS advisor, Radiation Safety Officer) and that these are to be reviewed annually. Two HIRAM’s were supplied for the facilities: one specific to the teletherapy sources and another relating more broadly to the basement area which aims at capturing the linacs, teletherapy sources, kV x-ray units, neutron sources, etc. While the basement area HIRAM has been signed by all staff involved with the area and is currently approved, the same could not be demonstrated for the teletherapy sources (though this was remedied between the virtual inspection and the exit meeting) and no specific HIRAM has been developed for the linacs.

In terms of review in accordance with the aforementioned manual, discussion was held as to whether or not a record of the document being viewed (i.e. accessed) within ARPANSA’s record management system would suffice. This is not considered a proper review as it does not include an analysis of the continued appropriateness of the document with evidentiary support to demonstrate that such a review took place. While it is unnecessary to expect that each document review necessitates an update, especially if no changes are required, demonstration that a review took place is considered standard practice. To do this, the WHS Manual makes reference to ARPANSA-FORM-XXXX-HIRAM Part D – Review Supplement, which refers to a document that has not yet been created. Further, multiple incomplete references to documents exist within the manual and it is within days of the three-year regulatory review period though it is acknowledged that ARPANSA’s WHS framework has undergone an extensive audit and is in the process of being revised in its entirety. All of the above contribute to an area for improvement.

The previous inspection (R19/05335) revealed an AFI that the change control process at ARPANSA is not sufficiently comprehensive to cover the change categorisation in terms of safety impact, internal review and approval procedures, including the external regulatory approval. There has been positive progress noted in the documentation management, particularly review and updating since the last inspection. A new system is currently in its final stages of development and waiting on feedback from stakeholders prior to its implementation. Until this new system is put in place, the management of change is largely informal.

A recent example highlights the importance of having effective change management processes in place and is directly linked to the aforementioned AFI from the previous inspection. MRSB’s Elekta Synergy linac has been subject to a recent upgrade to modernise the linac head. An Elekta engineer was working in the gantry area and had concerns relating to the arrangements in place for the interlock system. He was unable to contact ARPANSA’s engineering services provider due to COVID isolation. The Elekta engineer received a verbal approval to proceed and make the system safer for his work.  He installed additional wiring to connect the interlocks together in series to ensure that the gantry could not be moved by anyone in the control room. After the engineer had completed his work, he left the site without completing a proper handover, leaving the wiring in place which prevents operators placing the linac in user-mode.

Though there are issues with the SAR, such interlocks are considered a safety category 2 system (i.e. perform a function which is required to reach a safe state (stoppage of the linac beam) and whose failure may result in consequences of high severity) and is therefore considered important to radiation safety. MRSB did not consider whether such a change required prior approval under section 63 of the Regulations and as such no formal safety determination was performed. Though the change added a layer of safety to allow the engineer to perform his work it was never intended that it remain in place; it also signals a loss of effective control. The engineer left the site without removing the wiring or conducting a proper handover. Had the installation of wiring across the interlocks been improperly executed, there is potential that an exposure situation could have arisen. A change to such a system without prior approval of the CEO of ARPANSA is considered to be a non-compliance. It is important to note that though there is potential for an exposure situation, no such situation arose and therefore no safety consequences were realised.

Inspection, testing and maintenance

The teletherapy facilities were purpose-designed to require minimal to no maintenance which ensures the risk of exposure from such activities is kept to a minimum. Recently, the air compressor for the system was successfully upgraded to ensure a reliable source of compressed air and a light bulb of the source status notification system was changed. Should an issue occur that requires more involved maintenance actions, internal consultation would take place between the Radiation Protection Advisor, Radiation Safety Officer and ARPANSA’s engineering services to workshop a solution. Depending on the failure scenario, MRSB would contact the original supplier for information to allow safe repair or, if this is not possible, potentially bring them onsite to perform the required maintenance work. To date, such a malfunction requiring the original supplier has not occurred.

Maintenance on both Elekta linacs continues to be performed solely by Elekta engineers. Elekta, being the manufacturer, sets the schedule for preventative maintenance which is performed on a regular basis and supplemented by reactive breakdown maintenance. Trained linac support officers also perform in-house maintenance but only in relation to simple electronics (e.g. replacing of fuses).

MRSB ensures that the interlock systems on the teletherapy facilities and linacs are tested frequently. This has been demonstrated by compliance with the agreed test frequency for the teletherapy facilities. Though it was claimed that the interlocks are tested for both linacs, only the Elekta Versa HD appears to have a formal record of annual testing.

ARPANSA inspectors reiterated the importance of continuing the self-assessments with applicable codes and standards as part of licence condition 2 of licence F0046 and applying a graded approach to ensure that the facilities remain compliant. In this case, the applicable code relating to the linacs is the Health Physics Society (HPS): Installations using non-medical x-ray and sealed gamma-ray sources, energies up to 10 MeV (ANSI/HPS N43.3-2008). While the interlocks are frequently tested, the requirements are not being addressed in their entirety and this is considered an area for improvement.

Training

With respect to the previous inspection’s AFI regarding training, a mandatory general radiation safety training package has been rolled out across the entire organisation to ensure refresher training occurs. This is presented through a learning management system known as Learnhub. This system will eventually manage every aspect of training for the organisation, eliminating the paper-based system, and currently has the capacity to do so but has not been yet been fully rolled out.

Provision for authorisation of work has also been amended to ensure there is a separation so that layers of management cannot sign-off on themselves to continue working.

Event protection

The arrangements in place to protect the facilities from an external event are unchanged since the last inspection and as such the conclusion remains unchanged i.e. barriers to a fire event are considered appropriate.

Security

MRSB has a protective security system in place to protect the premises and also the security-enhanced sources it uses. Staff go through a process of vetting to obtain security clearances which are undertaken by the Australian Government Security Vetting Agency (AGSVA) and are commensurate with the requirements of their position (e.g., baseline, NV1, NV2 or positive vetting). Swipe card access controls entry to the building beyond the reception desk with increased security measures in place to protect sealed sources which have been categorised in-line with the Code of Practice for the Security of Radioactive Sources (RPS-11) and are therefore considered a security risk.

Through discussion, it was apparent that there is still some separation between MRSB and the agency’s security function. Though the agency security function may ensure that requirements are being met (i.e. security maintenance, reviewing security plans, access control, response testing), it is MRSB as the licence holder who is responsible and greater engagement should take place between the two to ensure reliance is minimised. This is considered an area for improvement.

To date, there have no actual security events involving the teletherapy facilities.

Radiation protection

MRSB documentation substantiating derivation of dose constraints is unclear. Both SARs and other procedures reference a 2 mSv/y dose constraint. This is inconsistent with ARPANSA’s Control of Radiation Exposure document which describes how an ARPANSA-wide dose constraint has not been set as routine work is not expected to exceed the public limit (1 mSv/y) and that if it is foreseeable that such an exceedance were to occur, a workgroup-based constraint would be defined. MRSB’s Elekta Synergy Linac Safety Precautions documents also list a safety factor of 50. However, in the context provided, it appears this applies to the dose constraint as opposed to its actual implementation against instantaneous dose rate (i.e. 40 µSv/y versus 40 µSv/h). These inconsistencies contribute to an area for improvement.

Instrument calibrations were provided and found to be up to date; wipe tests of the sources have been performed and confirmed no leakage. Exposure of staff continues to be low and annual surveys are performed of all facilities. However, in relation to the linacs, the survey performed on the Elekta Versa HD linac is only ever 50% complete. Dose rates readings are not measured on the floors above as per the initial survey carried out during commissioning and neither linac has the survey completed to measure worst case exposures.

In the case of the incomplete survey, sound reasoning was verbally provided as to why the survey is performed in that manner. However, this has not been incorporated into the written process to justify its exclusion. In relation to surveying the exposure scenario, the worst-case exposure should be surveyed in order to provide assurance that the protection measures in place continue to meet their objective. These issues are considered an area for improvement.

Emergency preparedness and response

ARPANSA inspectors and MRSB staff discussed the process of evacuation in an emergency, predominantly in relation to the teletherapy facility. The fire warden for the basement is also the RPA responsible for the teletherapy sources and confirmed that the sources will be retracted, the room will be locked out and then the remainder of the areas checked to confirm no staff remain present. After being given the all-clear by the Chief Warden, the room will be checked to ensure sources are secure. If the fire warden for the basement is unavailable, other appropriate members of the MRSB will verify the conditions in the facility.

For the Yallambie location, ARPANSA has developed a set of emergency response procedures (ARPANSA-SOP-1468). While the content of the documents is adequate, the document which does have multiple revisions does not appear to have been approved or has an approval date recorded. Also, no evidence of the required annual review could be demonstrated.

ARPANSA’s Radiation Safety Strategy document (ARPANSA-SOP-1429) also lists emergency documents within (ARPANSA-SOP-1432 – Emergency Procedures involving Radiation Exposure and ARPANSA-SOP-1443– Radiological Incident Reporting procedure) but these have been found to be placeholders in ARPANSA’s records management system for documents that have not yet been developed.

These issues are considered contributors to an identified broader area for improvement.

Findings

The inspection revealed the following non-compliance/s:

1. The licence holder did not obtain prior approval from the CEO of ARPANSA to make a change that potentially had significant implications for safety.

The inspection revealed the following areas for improvement:

1. The arrangements for document control should be improved to ensure that information is clear, current and appropriate, and that requirements are being met.
2. Inspection, servicing and testing of interlocks and other safety devices should be in accordance with the requirements of ANSI/HPS N43.3-2008.
3. Radiation surveys should clearly and accurately identify their scope and be conducted in a manner which ensures that the controls in place continue to meet their performance requirements.
4. The licence holder should be engaged with the security function of the agency rather than reliant on others to ensure requirements are met.

It is expected that improvement actions will be taken in a timely manner.