U 3&4 compliance with National and International Standards

septembrie 6, 2011 by  
Filed under Technology

Cernavoda 3&4 civil construction was started in the 1980s, but was later stopped and the project has been largely inactive ever since. About 50 percent of the civil work was completed for Unit 3 and about 30 percent was completed for Unit 4. This includes partial construction of the two reactor buildings and service buildings / turbine buildings. Besides the civil work, very little other construction activity, such as equipment installation, was ever begun.

With the exception of the existing civil structures, Cernavoda 3, 4 is being  considered as a new build NPP.

As such, the Cernavoda 3&4 design is considering modern safety and licensing requirements.

These include requirements from:

  • Western European Nuclear Regulators Association (WENRA)

Western European Nuclear Regulators Association (WENRA) Reactor Safety Reference Levels was issued in January 2008, with an aim to harmonize the safety approaches for nuclear power reactors of European Union member states.

Compliance assessments of Cernavoda Units 3&4 against the WENRA Reactor Safety Reference Levels have been performed.

The emphasis given to the current compliance assessment of the WENRA Reference Levels is on the safety areas that are relevant to the design of Cernavoda Units 3&4.

The review of WENRA clauses shows that Cernavoda Units 3&4 are compliant with the WENRA Reference Levels. The improvements applied to the design of the reference plant, to both deterministic and probabilistic safety analyses (including beyond design basis events) or to the design documentation ensure 100% compliance with the requirements of WENRA.

  • European Utility Requirements (EUR)

The objective of the EUR document is to develop requirements addressed to the LWR plant designers and vendors. It basically provides a tool for harmonization of the key plant features which are often too nation-specific. The important items considered in this convergence process are the safety design, safety targets, safety criteria and assessment methodology, standardization of environmental qualification requirements, plant performance targets, and design features of main systems.

Compliance assessments of Cernavoda Units 3&4 against the European Utility Requirements (EUR) have been performed. The assessment results show that the C3/4 satisfies the EUR requirements or the intent of these requirements.

  • International Atomic Energy Agency (NS-R-1) and Canadian Nuclear Safety Commission document RD-337, “Design of New NPPs”

RD-337 represents the CNSC adoption of the principles set forth by the IAEA in NS-R-1, Safety of Nuclear Plants: Design and the adaptation of those principles to align with Canadian expectations.

This regulatory document includes requirements for Station blackout, Mitigation of severe accidents, Hydrogen mitigation, External events, Fire protection, etc.

A compliance assessment of Cernavoda Units 3&4 against RD-337 “Design of New NPPs” has been performed. The review of RD-337 clauses shows that Cernavoda Units 3&4 are compliant with the RD-337, “Design of New NPPs”

  • Equivalence with Generation III reactors

The World Nuclear Association (WNA) defines Generation III reactors as those designs that are evolutions of the proven Generation II designs, with enhanced safety and reliability and to be cost-effective, in particular, defined by:

  • a standardized design to expedite licensing, reduce cost and construction time,
  • a simpler and more rugged design for easier operation, and less vulnerable to operational upsets,
  • higher availability and longer operating life – typically 60 years,
  • reduced possibility of core melt accidents,
  • resistance to serious damage that would allow radiological release from an aircraft impact,
  • higher burn-up to reduce fuel use and the amount of waste, and
  • burnable absorbers (“poisons”) to extend fuel life.

The Cernavoda Units 3&4 have all of the traditional proven features of the CANDU 6 design. In addition, by implementing several safety enhancements, the integral safety level of these units is equivalent to the world class new build of Generation III and Generation III+ reactors.


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