The Hindu Business Line : Security checks — Need for non-intrusive scanning

Most of those who travel by air these days would be resigned to the hassle of being subjected to a series of security checks at airports and their baggage being put through scanning machines. The exercise is essentially to ensure safety of the passengers and a check on the material being flown out. The growing passenger and cargo traffic at airports, sea ports and border crossings has necessitated such security measures.

What happens in the airport situation is the following. Your baggage is scanned by an X-ray screening system, which generates a visual picture of the contents to the operator, who is trained to scan the monitor and detect any suspicious material.

This is just one of the examples of a quick, non-intrusive inspection technology that has made inroads as far as commercial applications are concerned. This principle has been exploited to put a check on the material that is being carried into aircraft or even buses/trucks or ships, as the case may be.

Cargo boom, a challenge

The idea is to ensure that no false declaration is made to illegally carry away armaments, ammunitions, explosives or other dangerous materials and cause avoidable problems. The new international airports coming up in Hyderabad, Bangalore, Kochi and many domestic terminals need to have sophisticated screening equipment to ensure passenger safety.

With India experiencing a boom in its cargo business and movement of material through various trade routes such as ports, airports and roads, the challenges confronting agencies that need to ensure the quality and safety of the goods are growing manifold .

The country today exports more products to various global destinations and there is a quantum jump in imports as well. The projections for the air cargo business in India as per the Union Ministry of Civil Aviation are 33,60,000 tonnes by 2010.

The cargo traffic through the 12 major and 187 minor ports during 2005-06 was 570 million tonnes, 75 per cent of which was through major ports. The projected target is 877 million tonnes by 2011-12.

How does one keep a track of the movement of goods, that too without inconveniencing the exporters/importers, rapidly check the material and ensure safety? In short, the need is to have systems that are fully automated, intelligent and reliable to quickly verify the contents of a container in a non-invasive way.

‘Intelligent’ technologies

The national objective is to make the country’s seaports, airports, border crossing and check-posts ‘intelligent’. Experts believe that non-intrusive inspection technologies offer the most practical solution to these challenges at present. Some of these technologies are high-energy X-ray radiography systems, gamma ray radiography, Backscatter, Transmission X-ray scanning, Thermal Neutron Analysis (TNA) and Fast Neutron Analysis (FNA).

Of these, X-ray and gamma ray imaging systems have already made it to the commercial market and are being used across the world, including in India at the airports and the Jawaharlal Nehru Port Trust (JNPT) in Mumbai, where approximately 7,000 containers are handled per day, says Mr V.H. Ron, Managing Director of ECIL Rapiscan, a key player in the security systems industry.

The broad objectives of these systems are to assist inspectors (from Customs, BSF, the Revenue Department, etc.) to verify containerised cargo, baggage, scan for contraband stuff, etc. The dosage used while scanning by both X-ray and gamma ray systems is said to be within safe limits.

False declaration

According to Mr K. Govindarajan, formerly of the Bhabha Atomic Research Centre (BARC), there is an important economic angle to the entire exercise.

Effective control on the movement of cargo across these routes means prevention of false declaration of goods as well as illicit trafficking in arms, ammunitions, explosives, narcotics and drugs, hazardous chemicals, radioactive and nuclear material.

Such trafficking, according to Mr Govindarajan, not only has economic implications, such as collection of taxes and duties, but also poses a grave threat to the security of the country. Therefore, the urgent need to have relevant, cost-effective systems that can manage this rapidly growing sector.

In the US, for example, the Government has initiated the Container Security Initiative (CSI). It consists of a security regime to ensure that all containers that pose a potential risk of terrorism are identified and inspected at foreign ports before they are placed on vessels destined for the US.

X-Ray, Gamma Ray

One important element of the CSI is the mandatory use of technology to pre-screen high-risk containers without slowing down the movement of trade. The technologies identified for use are large-scale X-ray and gamma ray machines and radiation detection devices. The CSI is a reciprocal programme, and offers its participant-countries the opportunity to send their Customs officers to major US ports to target ocean-going, containerised cargo to be exported to their countries. “Here lies an opportunity for countries such as India to enhance exports to the US and other countries by complying with CSI,” says Mr Govindarajan.

What are the technological options available at present for India? While, it is a fact that no single technology solution exists for detecting weapons, drugs, explosives as well as nuclear materials, there certainly is the option of deploying a combination of technologies, depending on the challenge, to sort out the issues.

While you are familiar with X-ray baggage screening, inspection of containers calls for substantially higher-energy X-ray machines. Hence, high-end systems for cargo screening need 9 million electron volt (MeV) X-ray generators, compared to the 160 KeV used in baggage scanners.

Gamma Ray Radiography Inspection Systems: These systems normally employ sources such as Cobalt 60 or Cesium 137, to generate gamma rays. The system provides an image of the contents as picked up by the gamma ray photo-multiplier scintillation counters also called gamma detectors. The energy level deployed is limited to 1.33 MeV. This allows penetration of up to 190 mm of steel.

Hence, the use of gamma rays scanning is restricted to lightly loaded containers and trucks. The advantage is that the mobile systems can be driven around ports to inspect containers as they are loaded or unloaded. They can inspect containers as they are driven through the inspection portals as well. At present, more than 200 gamma-ray-based container scanning systems are functioning across the world.

Backscatter and Transmission X-Ray Scanning: Transmission X-rays penetrate layers of materials and are capable of detecting weapons, metallic bomb components concealed in cargo, etc.

However, they could miss out on items such as plastic weapons, explosives and drugs that are usually transparent to X-rays, particularly if they are placed in false compartments on the surface of cargo containers.

To overcome these problems, the backscatter X-ray technology has been added. This allows easy detection of contraband hidden in false compartments and near the surface region of a typical container/truck.

Now, the bigger task confronting security agencies is the detection of weapons, explosive materials, chemicals and radioactive devices that can cause great damage. Similarly, the tricky job of finding out contraband or narcotics that are camouflaged calls for more sophisticated techniques.

N-tech advantage

Advances in nuclear technology provide some interesting leads. However, the greater the sensitivity, the higher the chances of false alarms also, which can be sometimes irritating, explains Mr Govindarajan. Nuclear techniques are inherently non-intrusive and the data they generate is amenable to advanced data analysis methods and automatic decision-making.

According to him, neutrons are also preferred for probing radiation, especially when material specificity is required. Fast and thermal neutrons, in micro or nanosecond pulses are capable of detecting explosives, drugs, chemical agents and nuclear and many other illegal materials.

Thermal Neutron Analysis (TNA): The applications include detection of explosives and drugs. TNA is designed to prevent vehicle and container bombs. It is the simplest of all neutron-based techniques and can be deployed independently.

Fast Neutron Analysis (FNA): This is among the low-cost methods in neutron techniques with the ability to probe deep into the material content of the object and recognise multiple signatures. However, the imaging is limited to smaller objects. The PFNA, though expensive, is an improvement over the above method. It uses short bursts of neutrons travelling at specific velocity to scan the complete volume of the containers.

Slow progress

Ironically, despite two installed systems working well at the JNPT, the Government seems to be a bit slow in deploying similar systems across other ports and sensitive areas. The fact remains that indigenous technology to develop low-cost systems exists with the BARC.

Also, several companies have started getting into the field to offer systems. In contrast, China has more than 25 systems commissioned for the last five years, that too with a large percentage of indigenisation.