Objectives

The primary objective of this tender is to procure a specified number of Electronic Personal Dosimeters (EPDs) that meet the functional, technical, safety, and environmental requirements outlined by Necsa. The goal is to ensure accurate measurement, calculation, and display of radiation exposure levels for personnel working in radiation-prone environments, thereby enhancing safety and compliance with regulatory standards.

Scope

The scope of this tender includes:

• Provision of 10 units of Electronic Personal Dosimeters (EPDs) as detailed in Appendix A.
• Supply of devices capable of measuring personal equivalent dose rates Hp(10) and Hp(0.07) for gamma, X-ray, and beta radiation.
• Delivery, installation, calibration, and testing of the devices to ensure compliance with specified standards.
• Provision of data recording, readout capabilities, and support for software interfacing via serial, infrared, or Bluetooth connections.
• Ensuring devices are lightweight, rugged, and suitable for use under various environmental conditions, including temperature and humidity ranges specified.
• Providing warranty, spare parts, and maintenance services for a minimum lifetime of 10 years.

Technical Requirements

Functional and Performance Requirements

The EPDs must:

• Measure, calculate, and display radiation dose rates (Hp(10) and Hp(0.07)) accurately.
• Support at least two preset warning levels for dose and dose rate modes.
• Be sensitive to continuous X-ray, gamma, and beta radiation.
• Be lightweight, self-contained, with a clip and strap for comfortable wearing.
• Feature a minimal button interface for ease of operation.
• Have a digital display indicating dose, dose rate, and alarm status under all operating conditions.
• Include alarm indicators (visual and audible) for exceeding preset safety thresholds.
• Have an outer surface that is easy to decontaminate.

Technical Specifications

• Safety Standards: Compliant with IEC61508-1, 61508-2, 61508-3.
• Physical Dimensions: Volume ≤ 120 cm³; Weight < 100 g with built-in batteries.
• Data Recording & Transfer: Ability to record data and transfer via serial, infrared, or Bluetooth interfaces.
• Display & Interface: Support for multiple languages (display results in SI units, menu in English).
• Detectors: Sensitive to X-ray, gamma, and beta radiation, self-contained with no external detectors required.
• Modes of Operation: Two modes—dose rate and accumulated dose—with manual switching capability.
• Measurement Ranges & Accuracy:
  • Dose rate Hp(10): 0 to ≥50 Sv/h, resolution ≥1 µSv/h, accuracy ±10% for Cs-137.
  • Hp(0.07): 0 to ≥50 Sv/h, resolution ≥20 nSv/h, accuracy ±15% (Cs-137) and ±20% (Sr-90/Y-90).
  • Accumulated doses: 0 to ≥15 Sv, resolution in µSv, accuracy within ±20% (Hp(10)) and ±30% (Hp(0.07)).
• Alarm Features: Audible (≥95 dBA) and visual alarms with adjustable thresholds, different sounds for different alarms, and indication messages.
• Environmental Tolerance: Operational from –10°C to +50°C, resistant to rapid temperature changes, withstands up to 90% humidity at 40°C, ingress protection rating IP55.
• Reliability & Maintenance: Minimum lifetime of 10 years, MTBF ≥4 years, MTTR ≤4 weeks, ongoing availability of spare parts and maintenance services.
• Calibration & Compliance: Must be calibrated locally by SANAS-accredited laboratories and meet regulatory standards set by SAHPRA and NNR.