Inspection report: Australian Submarine Corporation Pty Ltd (ASC), SA, 5 November 2020

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 source licence S0190.

The scope of the inspection included an assessment of ASC’s performance at ASC North Osborne against the Source Performance Objectives and Criteria (POCs). The inspection consisted of a review of records, interviews, and physical inspection of sources. Emphasis was placed on high-dose radioactive material used for non-destructive testing during this inspection.

Background

ASC is licenced for a range of non-destructive testing equipment and controlled apparatus for the purpose of assessing the quality of submarine components during maintenance periods. 

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

• Radiation Protection Series 3: Radiation Protection Standard for Maximum Exposure Levels to Radiofrequency Fields - 3 kHz to 300 GHz (2002)
• Australian/New Zealand Standard: Safety in Laboratories - Non-Ionizing Radiations - Electromagnetic, Sound and Ultrasound (AS/NZS 2243.5:2004)
• ICNIRP Guidelines for Limiting Exposure to Time-Varying Electric and Magnetic Fields 1 Hz - 100 kHz (2010)
• ICNIRP Guidelines for Limiting Exposure to Electric Fields Induced by Movement of the Human Body in a Static Magnetic Field and by Time-Varying Magnetic Fields Below 1 Hz (2014)
• Australian/New Zealand Standard: Safety of Laser Products Part 1: Equipment Classification and Requirements (AS/NZS IEC 60825-1:2014)
• Australian/New Zealand Standard: Safety of Laser Products Part 14: A User's Guide (AS/NZS IEC 60825-14:2011)
• Radiation Protection Series C-4: Code of Radiation Protection Requirements for Industrial Radiography (2018)

Observations

The inspection team observed a very strong safety and security culture at the Osbourne facility However, there appeared to be limited areas for improvement with respect to establishing emergency procedures and dose constraints for life saving actions, conducting emergency exercises to test arrangements, recording the acquisition and movement of all sources used on site and, establishing an industrial radiography awareness program for non-radiation workers. 

Performance reporting verification

ASC regularly provide their quarterly reports in a timely manner and these contain relevant information regarding the acquisition and disposal of sources as well as revisions of plans and arrangements. The inspectors found ASC’s performance on this module to be satisfactory. 

Configuration management

ASC have two main operating configurations. A dedicated closed-site exposure room is used within the non-destructive testing precinct and, open-site exposures are conducted on the boat on and around the Maintenance Support Tower (MST). These different configurations require different arrangements of personnel, sentries, communications and exposure control techniques in accordance with the RPS-C4 code of practice. ASC’s plans and arrangements adequately described the appropriate procedures for these different operating environments.

Training

ASC described a tiered system of training provided to their staff depending on the role in non-destructive testing that they perform. Staff are either trained to level 2 or level 3 in accordance with the Australian Institute for Non-Destructive Testing (AINDT) certification requirements. These records were sighted during the inspection. Radiation Safety Officer training provided by ANSTO are also undertaken periodically. 

Event protection

There are a range of events that could lead to the damaging of NDT sources while in storage or operation that ASC have taken into consideration. Sources are stored in a configuration that prevents damage from flooding/water ingress into the source storeroom. Further, combustible materials are absent from storage locations and fire suppression systems are installed. The inspectors found that the safety and security considerations for event protection were satisfactory.

Security

ASC maintains an appropriate security plan in accordance with the Code of Practice on the Security of Radioactive Sources (2006).

Radiation protection

The two primary documents that cover ASC’s radiation protection arrangements include the Radiation Safety Manual and the Radiography Technical Manual. There are a suite of other associated documents that also support these two documents in ASC’s quality management system. It was explained that periodically ASC temporarily use sources provided by a 3rd party South Australian-licenced entity, who transport and deliver the sources to the ASC site, and ASC then uses these sources for non-destructive testing purposes. While ASC maintained accurate records for their acquisition and movement of their own sources, it was agreed that ASC would also benefit by maintaining records of sources that they temporarily use from 3rd parties. 

During the physical inspection and tour of the MST, it was revealed to the inspection team the highly-complex nature of working and operating at heights around the boat across multiple levels. High levels of industrial noise, high levels of activity, heavy plant equipment and the application of prescriptive rules for signing on and off different tasks across the MST reflected this notion. With this in mind it became clear that while ASC NDT staff tend to use sources for imaging purposes after hours or during times where there is little presence on the MST or boat, that there is a non-zero possibility of non-radiation worker personnel unwittingly approaching a zone where testing may be occurring. It was agreed that a non-destructive testing awareness campaign would benefit the already comprehensive induction training provided to non-radiation workers at the site to further enhance safety. 

Emergency preparedness & response

ASC maintain emergency procedures for a range of credible scenarios such as: isotope being sheared off while in delivery tube, lost or stolen source, high dose accidents and other scenarios. The procedures describe the physical actions to be performed and they accurately calculate the significant doses that may arise as a result of recovery operations. However, the scenarios do not recognise the significantly elevated dose limits that apply to emergency exposure situations and specifically those for life saving actions. It was agreed that ASC should revise the emergency dose limit considerations in accordance with RPS-G3 and exercise relevant scenarios.

Findings

The licence holder was found to be in compliance with the requirements of the Act, the Regulations, and licence conditions. 

The inspection revealed the following areas for improvement:

1. ASC should review the elevated doses permitted for life-saving actions contained within RPS-G3, update their plans as necessary and exercise to these scenarios.
2. ASC should record the temporary acquisition, movements and use of sources provided by 3rd parties.
3. ASC should introduce a non-destructive testing awareness program as part of induction for non-radiation workers on the MST.

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