Inspection report: CSIRO Agriculture and Food, R24/02151

This is the record of an inspection conducted as part of ARPANSA’s source 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 S0021. The scope of the inspection included an assessment of performance at A&F Toowoomba against the Source Performance Objectives and Criteria (SPOC). The inspection consisted of a review of records, interviews, and physical inspection of the source and source store.

Background 

The licence holder is authorised under section 33 of the Act to deal with a sealed source with a mobile gauge. The CSIRO A&F site has one security category 4 portable neutron moisture meter (NMM) containing an Am-241/Be source used to determine soil moisture content at various depths for cropping experiments. The main codes and standards applicable to this licence are: 

• RPS C-1 Code for Radiation Protection in Planned Exposure Situations (Rev 1) (2020) 
• RPS 11 Code of Practice for the Security of Radioactive Sources (2019) 
• RPS C-2 Code for the Safe Transport of Radioactive Material (2019) 
• RPS 5: Code of Practice and Safety Guide for Portable Density/ Moisture Gauges containing Radioactive Sources (2004) 

Observations

In general, the management of safety and security was found to be satisfactory. In some cases, however, there appeared to be room for improvement with respect to documentation, and access control over keys for access to a store. The use of an ‘air tag’ to enable the responsible person to track the location and account for a portable gauge at all times was identified as good practice.

Effective control

Accountabilities and responsibilities

The CSIRO A&F Director (Licence Holder Nominee) is responsible for overall radiation safety within A&F including the appointment of site Radiation Safety Officer (RSO) and ensuring sufficient funds for training. 

The Portable Neutron Moisture Meter and Soil Density Gauge Radiation Management Plan (PNM RMP) section D.3.2 requires that each CSIRO A&F site that utilises neutron moisture meters and density gauges must have a qualified radiation safety officer (RSO) that oversees the management of all aspects of the device’s use, including staff training, safe work practices, radiation monitoring, storage, transport, and periodic wipe testing. 

The Toowoomba Site Radiation Safety Contact position has recently been upgraded to a Site RSO role. The appointment letter to the new Toowoomba Site RSO role dated 28 February 2024 was provided during the inspection. 

In addition, CSIRO Chief RSO periodically conducts an internal controlled apparatus source compliance check for its neutron source at Toowoomba. The last compliance check was undertaken on 12 March 2023.

Statutory and regulatory compliance

CSIRO uses an electronic inventory management database (CSIRO Radiation Database) to internally manage information on the controlled material in the NMM (Am-241/Be source) at the Toowoomba radiation store. The Toowoomba source data is exported to the ARPANSA Licence administration database (LAD). The information on the neutron source (LAD number 666) held in the LAD database is up-to-date; and CSIRO is compliant with its quarterly reporting requirements under source licence S0021.

Resources

The Toowoomba site is adequately resourced for safely transporting the NMM during field work. For example, a CSIRO vehicle is available for transporting the source in a dedicated transport container with compliant radiation hazard signage and the means for securing the NMM to the tray of the vehicle. The inspection verified vehicle radiation placarding, and perimeter radiation warning signs are available. The radiation store is to be moved to an experimental farm site where crop and soil research is undertaken, and resources are available for the construction of a new radiation store on site which will meet the requirements of RPS 5 s5.1.

Documentation and document control

The CSIRO A&F Radiation Protection Plan Version 1.9 (June 2023) (RPP) contains a separate PNM RMP that addresses all the required elements of a Radiation Management Plan as identified in section 2.1 of RPS 5. However, the RPP contents page should include a heading ‘Appendix D Portable Neutron Moisture Meter and Soil Density Gauge Radiation Management Plan’ to distinguish the PNM RMP from the RPP in the combined document and clarify its location in Appendix D. In addition, the PNM RMP section D.7 refers to the 2014 edition of RPS C-2; however, the Code for the Safe Transport of Radioactive Material, RPS C-2 (Rev. 1) (2019) replaces the 2014 edition (RPS C-2) and the PNM RMP require updating.

Safety management

Risk assessment

The RPP section 3.3 Hazard and Risk Management requires all work with controlled radiation sources must be covered by a risk assessment. Safe Work Instructions (SWIs) are required to be developed for the use of controlled material and controlled apparatus by relevant staff in consultation with the Site RSO or RSC as necessary. SWIs for controlled material and controlled apparatus must be reviewed (with associated sign off) by the Site RSO, Business Unit (BU) RSO, or Chief Radiation Safety Officer, as required. The Toowoomba NMM SWI for ‘Use of Neutron Moisture Meters, A&F, Toowoomba’ requires annual review. The SWI for use of the NMM was confirmed to have been reviewed by the risk owner identified in the SWI on 08/03/2024. In addition, the CSIRO Activity Risk Assessment for Use of Neutron Moisture Meters, A&F, Toowoomba was confirmed to have been undertaken in March 2024. The document received review signoff by the HSE Reviewer on 7/2/2024; and line manager and senior manager approvals on 8/3/2024.

Monitoring and measurement

PNM RMP section D.4.3 Wipe Tests require wipe tests be conducted annually on Neutron Moisture Meter and Density Gauges that are less than 15 years old and bi-annually on the devices greater than 15 years. Wipe testing results from 21/3/23 and 29/2/2024 were examined during the inspection verifying the integrity of Am-241/Be source’s encapsulation. CSIRO advised that the NMM in use at the Toowoomba site was acquired in 2008 is now entering its sixteenth year of service and a wipe test check will be undertaken on a biannual basis. The SWI general advice information in the section ‘Wipe Testing of Neutron Moisture Meter Sealed Sources’ requires updating to align with the requirements of the PNM RMP. A radiation survey for the Radiation Store containing the CSIRO Neutron Moisture Meter and a Department of Agriculture Fisheries and Forestry (DAFF) owned source was undertaken on 12/3/2024.

Managing change

CSIRO is intending to move the radiation store for the portable radiation gauge to a new location. The A&F S0021 RPP section 6.4 which addresses Relocation and Storage requires staff consult with the BU RSO before relocating controlled apparatus [or material] to another site regardless of location. The relocation must be reflected in the CSIRO Radiation Inventory Database. The siting and construction issues for maintaining safety and security at a new store were discussed during the walkthrough of the existing radiation store. The Chief RSO also raised that discussions on the requirements of the store for safety and security were held with the architects involved in the building of the new site store. The availability of resources to manage this change in storage location is discussed above.

Training and education

The PNM RMP D.2.2 requires all CSIRO staff that use Neutron Moisture Meters and Density Gauges to have completed an appropriate radiation safety course. The SWI identifies a ‘NOST Sealed Radiation Safety Training’ or ‘NMM Radiation Safety and Regulatory Awareness Training’ as an appropriate course. CSIRO staff training records examined during the inspection verified that both users of the NMM had completed ‘Neutron Moisture Meter Radiation Safety & Regulatory Awareness Training’ in February 2024.

Learning and continuous improvement

A&F Site RSO demonstrated an awareness of a previous occasion in which CSIRO had to recover a Portable Neutron Moisture Meter at another site and a knowledge of the integrity checks to mitigate the potential for a gauge containing a neutron source to be come loose when in use.

Radiation protection

Planning and design of the workplace

Portable NMMs are intended for use in the field. The use of steel tubes with a sealed end at defined depths enable the safe use of the NMM in a controlled open site location when conducting experiments; and assists in planning for its safe retrieval in the unlikely event that the NMM is dislodged and requires removal by alternative means as outlined on page 7 of Safe Work Instruction (SWI) – Safe use of Neutron Moisture Meters, A&F, Toowoomba. See also Resources and Change Management (above).

Local rules and procedures

SWI version 2.1 (08/03/2024) examined during the inspection has been risk assessed and identified the competencies and training, radiation hazard and PPE; and contains procedures for the transport, pre-deployment and use of NMM; including emergency procedures and contact details for foreseeable emergency or uncontrolled event scenarios. 

Personal protective equipment

When using the NMM, a neutron dose rate meter must be used to ensure dose rates are kept to a minimum and the source is working as expected. Radeye GN model ratemeters are provided for this purpose.

Monitoring of the workplace

The RPP s4.11.2 Table 14 Radiation Meter Calibration Requirements stipulate the calibration frequency for ‘ionising radiation – Dose -related meter’. The Toowoomba radiation meter is compliant with CSIRO’s RPM calibration requirements and is next due for calibration in June 2024. The PNM RMP annexed to the RPP also addresses the survey meter calibration requirements by referring to the RPP; however, as the PNM RMP is directly applicable for portable neutron moisture meter use it should refer directly to the specific requirements in RPS 5 Schedule C2.

Monitoring of individuals

The SWI requires Neutron Dosimeters Badges must be worn at all times when dealing with the NMM.

Transport

The PNM RMP section D.7 requires that NMMs must be transported in accordance with RPS C-2. The SWI for transport incorporates the requirements of RPS C-2 and RPS 5. The inspection confirmed: 

• Appropriate Class 7 Placards are displayed on the front doors and tailgate of the transport vehicle. 
• The NMM is transported inside a locked transport case with the source fully retracted and key locked in the shielded position. 
• the use of a user logbook when the gauge is removed from storage prior to departure.

Security

Security procedures

The NMM is stored in an external store. The storage practices generally meet the requirements of RPS 5. However, RPS 5 section 5.1.2 requires that the store must be kept under the control of the Responsible Person. In addition, PNM RMP section D.6 Storage of the Neutron Moisture Meters and Density Gauges generic storage requirements state: ‘The storage room must be kept locked with access only available to authorised users.’ 

The NMM store is a shared use space with another Australian Government Department. In addition, although the key to the store is kept in a key safe; persons other than the Responsible Person has access to the safe for the purpose of acquiring vehicle keys. It is recommended that access to the key for the NMM is only accessible by the Responsible Person. It is noted that CSIRO intends to vacate this storage site and build a new radiation store. In the interim, it is recommended that CSIRO review its radiation store key access controls at the Toowoomba store. 

CSIRO took immediate action to resolve this issue with the purchase of a separate safe for the key to the radiation store which is only accessible by approved users of the PNM. Photo evidence was provided on the 15/3/2024. CSIRO’s SWI for dealing with the NMM in transit, overnight storage and when in use, reflect the requirements of RPS 5 and PNM RMP are assessed appropriate for maintaining control over the gauge when in use. 

The NMM has an ‘air tag’ attached which demonstrates CSIRO’s commitment to maintaining awareness of the location of a portable source; and supports the responsible person be accountable for the radioactive source ‘at all times’ as required by RSP 5 section 6.4.1. The tracking capability provides a means of locating and recovering a lost or stolen source. The introduction of ‘air tags’ for tracking source's movement is considered good practice.

Emergency plans

Emergency procedures

The PNM RMP has emergency and recovery procedures for a range of foreseeable scenarios including the NMM being lost down an access tube in the field; fire or vehicles accident (including running over the probe); and theft of the NMM or the transport vehicle containing the NMM in its transport container.

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: 

• Minor correction and updates to plans and arrangements. 
• Control over the key for accessing the NMM to be limited to the responsible person. 

The inspection revealed the following good practice: 

• The use of an ‘air tag’ for tracking the source location at all times. 

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