Wednesday, August 10, 2011

Safety, Security and Environment Protection in Nuclear Sector

  Public acceptance, opinion and diligence of policy makers and planners as well as political consensus are vital for deciding on issues like Energy mix for India, its nuclear policy and its nuclear contribution to the energy mix. These need to be arrived at on a country specific manner. Only Nuclear Energy that does not cause any harm to public and environment will be acceptable to public. Safety, security and environmental protection of Nuclear Industry are brought about by multi-organizational, multi-disciplinary and multilayered approach. In addition these need to be taken care of at all stages from cradle to grave i.e. from citing to decommissioning of each nuclear facility. This will explain briefly how safety is taken care of in nuclear industry and in India.

While the operator, Nuclear Power Corporation of India Ltd (NPCIL) in our case, is primarily responsible for safety, the Regulatory Body, Atomic Energy Regulatory Board (AERB) in India oversees and ensures safety. Firstly a Nuclear Power Plant (NPP) is located at a carefully selected site, keeping safety, security & environment protection in mind and as mandated by AERB code on siting. Design of NPPs is based on several concepts to ensure safety of its operation. These are defense – in – depth philosophy. Independent, redundant and diverse safety trains, fail safe, single failure criterion (failure of one equipment will not affect the function) etc. For example, for many generations 3, 3+ NPPs which India would be importing, four independent, redundant, diverse safety trains are provided, each train capable of providing 100% safety. It is just like providing a car with four independent and redundant brake systems, starting from four brake pedals and finally up to four brake liners with each set capable of giving 100% protection of stopping the car.

Highest standard of Quality Assurance is adopted during subsequent manufacturing of equipment, construction activities, and commissioning. Finally the plant is operated by staff possessing highest levels of safety and security cultures. Safety & security culture ensures safety and security considerations override others such as cost, schedule, production, commercial etc. A simple definition of safety & security cultures is when everybody in the organization like NPCIL does the right thing with respect to safety and security when nobody is looking at them. The safe operation is practically demonstrated by actual safe, secure, reliable and viable operation of more than 330 reactor years completed by 20 NPPs in India.

Activities in all these stages are reviewed, licensed through stipulations, enforced and inspected by AERB. All reviews are detailed and comprehensive, based on AERB safety documents including codes which are based on International Atomic Energy Agency (IAEA) documents, thus adopting the current international standards and best practices. These reviews are done by various expert groups, many outside DAE and through three tier committees. For example, the design review by AERB for Narora took five lakh technical man hours. Similar review is mostly completed for the Russian plant at Kudankulam and will be done for other imported reactors. Incidentally imported NPPs are to be licensed by host country as well as AERB.

The safety performance of the 20 NPPs run by NPCIL has been satisfactory. This has been demonstrated by 3000 annual samples of grass, fish, milk, goat thyroids etc taken around each NPP and analyzed by independent MOEF accredited Environmental Survey Laboratories. Results indicate that due to the operation of these 20 NPPs, Public get less than 1% addition to the existing natural background of 2 radiation which they would be exposed to whether NPP is there or not i.e. if natural background is 200 units, NPP will add two units of radiation i.e. public will be exposed to 202 units of radiation. It is also less than 5% of AERB limits, which are comparable to international safety limits.

No comments:

Post a Comment