Environmental Monitoring Systems for Radioactivity in Seawater


Seawater is mildly radioactive as there have been found substantial (albeit small) radioactive elements. These go through simultaneous radioactive decay and give out energy along with subatomic particles and a smaller residual nucleus.

The particles generated are of three major types: alpha particles (consisting of two protons and neutrons each), beta particles (electrons), and gamma energy. Since these are radioactive, they are also known as radionuclides or radioactive isotopes and are monitored with the help of environmental monitoring systems. The source of this radioactive material is natural for the most part, existing since the formation of the planet.

Types of Radioactive Nuclides Present Today

The Earth has three kinds of radioactive nuclides at present:

  • Primordial Nuclides: Seawater contains the following primordial nuclides –
    • 40 K
    • 87 Rb
    • 238 U
    • 235 U
    • 232 Th

Each of these has an incredibly long half-life and is largely scattered across the planet and its oceans.

  • Cosmogenic Nuclides: These radionuclides enter seawater through its surface. This type of radioactive particle is generated when high-energy cosmic radiation interacts with upper atmosphere gases to expel nucleons. The most important among these are
    • 14 C
    • 7 Be
    • 3 H (tritium)
  • Human-made Radionuclides: Human beings have been researching, working, and utilizing radionuclides for a century. Although they have added to the inventory and increased the number of natural radionuclides through nuclear power systems, weapons testing, and nuclear reactor waste among other tasks, it is a minor amount as compared to other sources.
    • The major artificial nuclides include –
      • tritium( 3 H)
      • 131 I
      • 129 I
      • 137 Cs
      • 90 Sr
      • 99 Tc
      • 239 Pu

These also enter the oceans through their surface waters and when nuclear waste is deposited via submarine reactors in the ocean, creating point sources of the waste on the seafloor.

Environmental Monitoring Systems Provided by NATS

NATS is a leading supplier of environmental monitoring systems for radiation detection and surveillance across the globe. We provide specialized systems for varying requirements when it comes to radiation analysis of seawater.

Our product range for marine and seawater radiation monitoring is available in three major categories:

  1. Remote, Real-Time, Online Measurement Systems – These are designed to be utilized in conjunction with a base station across a wide area. They can be deployed to work with radiation sensors controlled through remote command with data transmission to the base station.

It contains specially designed software for scalable system control and to display and analyze monitoring data. It can also be scaled up to include a greater number of stations and different kinds of sensors. Various modes for data transmission include VSAT, GPRS, Wireless, and WLAN or TCP/IP.

We offer a second type of monitoring system using gamma ray spectroscopy detectors. It enables remote control of sensors through TCP/IP-based data transmission.

Our third type of online real-time measuring system works without remote sensors. It is suitable for use at water inlets inside supply stations.

2. Submersible In-Spectroscopy Systems – These are based on high-resolution submarine Germanium detectors for the detection and analysis of deepwater gamma nuclides.

3. Laboratory Systems – These help in the analysis of water samples for the detection of all kinds of radiation. Our range of Laboratory Grade Systems includes the following:

    • High-resolution Gamma Spectroscopic Analytic Devices – These radiation detection systems use Sodium Iodide or Lanthanum Bromide Detector for Gamma Spectroscopic analysis.
    • Liquid Scintillation Counter – This is based on the innovative “Proton-Electron” Rejection Technique for LSC applications.
    • Alpha Spectroscopy Systems – These are designed to use Passivated Ion Implanted Detectors (PIPS) to identify radionuclides that release alpha particles.
    • Low-Level Alpha Beta Counting System – Use low-level gas flow radiation detection systems for seawater radiation