05 Mar 2024 : The Hindu Editorial

Topic 1 : Big Swedish study hints at link between bowel disease, infant diet

Context

Children who had a high intake of fish and vegetables at one year of age were at lower risk of developing Inflammatory Bowel Disease while those who had a higher intake of sugar-sweetened beverages at the same age were at higher risk.

IBD, types and factors

• Inflammatory Bowel Disease (IBD) describes disorders where the lining of the digestive tract is inflamed.
• There are two types of IBD disorders: ulcerative colitis, where the large intestine and the rectum are prone to inflammation and sores, and Crohn’s disease, which usually affects the small intestine.
• Researchers have reported diet, age, family history, cigarette smoking, and certain medications, among other factors, as being responsible for causing or worsening IBD.
• They have also said changing diet patterns can help explain changing patterns of the prevalence of IBD.

A diet that predicts IBD

• The diet of infants as young as a year old could affect their chances of developing IBD in future.
• The researchers suspect the developing gut microbiome may be at the heart of the apparent age-dependent relationship of dietary intake and IBD.
• The gut microbiome comprises a vast number and types of micro-organisms that live in the human gut.
• According to the authors of the Gut paper, it changes significantly through the first year and stabilises by the time the infant is two to three years old.
• A study found that infants may benefit from a “preventive” diet that includes “adequate dietary fibre, particularly from fruit and vegetables”, “intake of fish”, a minimal amount of sugar-sweetened beverages, and a preference of “fresh over processed and ultra-processed foods and snacks”.

The effect of fish

• The authors found that children who had a high intake of fish and vegetables at one year of age were at lower risk of developing IBD while those who had a higher intake of sugar-sweetened beverages at the same age were at higher risk.
• The content of poly-unsaturated fatty acids or vitamin D in fish may be of special importance for IBD.
• This is because, they add, previous studies on adults have observed that higher intake of PUFAs and Vitamin D are associated with lower risk of ulcerative colitis and Crohn’s disease respectively.

A ‘preventive’ diet for infants

• The  study didn’t account for additives and emulsifiers common in baby foods.
• These compounds have been implicated in accelerating IBD by changing the composition of the gut microbiome.
• Fruits and vegetables are high in dietary fibre and a high-fibre diet is implicated in IBD development and aggravation.

Conclusion

Especially with conditions like IBD, which have been shown to be aggravated by multiple triggers and their interactions with each other, interventions that provide one or the other foods or eliminate one or the other would not be advisable.

Topic 2 : The status of India’s nuclear programme

Context

On March 4, Prime Minister Narendra Modi witnessed the start of the process of core-loading the indigenous Prototype Fast Breeder Reactor (PFBR) at the Madras Atomic Power Station in Kalpakkam, Tamil Nadu.

PFBR and history

• The PFBR is a machine that produces more nuclear fuel than it consumes.
• Its core-loading event is being hailed as a “milestone” because operationalisation of the PFBR will mark the start of stage II of India’s three-stage nuclear power programme.
• In the first, India used Pressurised Heavy Water Reactors (PHWRs) and natural uranium-238 (U-238), which contains minuscule amounts of U-235, as the fissile material.
• In nuclear fission, the nucleus of an atom absorbs a neutron, destabilises, and breaks into two while releasing some energy.
• If the destabilised nucleus releases more neutrons, the reactor’s facilities will attempt to use them to instigate more fission reactions.
• The heavy water in PHWR — water molecules containing the deuterium isotope of hydrogen — slows neutrons released by one fission reaction enough to be captured by other U-238 and U-235 nuclei and cause new fission.
• The heavy water is pressurised to keep it from boiling. The reactions produce plutonium-239 (Pu-239) and energy.
• Only U-235, not U-238, can sustain a chain reaction but it is consumed fully in stage I.
• In stage II, India will use Pu-239 together with U-238 in the PFBR to produce energy, U-233, and more Pu-239.
• The Department of Atomic Energy (DAE) set up a special-purpose vehicle in 2003 called Bharatiya Nabhikiya Vidyut Nigam, Ltd. (BHAVINI) to implement stage II.
• In stage III, Pu-239 will be combined with thorium-232 (Th-232) in reactors to produce energy and U-233.
• Homi J. Bhabha designed the three-stage programme because India hosts roughly a quarter of the world’s thorium.
• The three stages are expected to make the country completely self-sufficient in nuclear energy.

The working of PFBR

• PHWRs use natural or low-enriched U-238 as the fissile material and produce Pu-239 as a byproduct.
• This Pu-239 is combined with more U-238 into a mixed oxide and loaded into the core of a new reactor together with a breeder blanket.
• This is a material the fission products in the core react with to produce more Pu-239.

• The PFBR is designed to produce more Pu-239 than it consumes.
• It uses liquid sodium, a highly reactive substance, as coolant in two circuits.
• Coolant in the first circuit enters the reactor and leaves with (heat) energy and radioactivity.
• Via heat-exchangers, it transfers only the heat to the coolant in a secondary circuit.
• The latter transfers the heat to generators to produce electricity.

Small Modular Reactors (SMRs)

• The delays brooked another potential complication in the form of Small Modular Reactors (SMRs).
• These reactor designs have a maximum capacity of 300 MW, require less land, and accommodate more safety features.
• SMRs can be installed at reduced cost and time by repurposing infrastructure in brownfield sites.
• They can work with low-enriched uranium, which India can import from the U.S. via its 123 Agreement.
• Increasing  SMRs’ contribution would require, among other things, amendments to the Atomic Energy Act (1962) and other related statutes to allow private sector participation under the oversight of the Atomic Energy Regulatory Body (AERB), with both nuclear fuel and waste controlled by the DAE according to international safeguards.

Way forward

On the flip side, bigger challenges await. FBRs are harder to handle than other reactor designs, whereas the DAE has acquired an unfavourable public reputation over its often heavy-handed response to safety concerns.