Large LOCA Margins in CANDU Reactors --an Overview of the COG Report

Abstract This paper discusses the background and conclusions of the 2007 COG report on Large LOCA Safety Margins in CANDU Reactors, and the various initiatives that have resulted from this study since its release. The COG study challenged the notion that positive void reactivity itself is a design weakness, raised as an issue at the Convention on Nuclear Safety, to demonstrate the safety of operating CANDUs worldwide when compared to other certified LWR designs. The paper will briefly describe a new perspective on how the seemingly complex analytical results on reactor safety parameters can be compared on a level playing field, in such a manner that the non-specialist is able to understand. The paper is presented together with a companion paper that focuses on the comparison of reactivity initiated events in CANDU with some other internationally accepted LWR reactor designs

Argonne National Laboratory Reports

The SYNBURN computer program for fast reactors will calculate all the neutronics necessary to completely characterize the equilibrium cycle as well as the startup to equilibrium cycles. The program's run time is very short and this makes the program suitable for survey of parametric studies. It can search on the cycle time for a specified burnup, for the shim control necessary for criticality as well as feed enrichments and the enrichment ratio among core zones. SYNBURN synthesizes in a very simple fashion the one-dimensional fluxes in radial and axial geometry to achieve an approximate two-dimensional solution which agrees very well with the exact two-dimensional solution when measuring regional integrated quantities

Large LOCA Margins in CANDU Reactors --an Overview of the COG Report

Abstract This paper discusses the background and conclusions of the 2007 COG report on Large LOCA Safety Margins in CANDU Reactors, and the various initiatives that have resulted from this study since its release. The COG study challenged the notion that positive void reactivity itself is a design weakness, raised as an issue at the Convention on Nuclear Safety, to demonstrate the safety of operating CANDUs worldwide when compared to other certified LWR designs. The paper will briefly describe a new perspective on how the seemingly complex analytical results on reactor safety parameters can be compared on a level playing field, in such a manner that the non-specialist is able to understand. The paper is presented together with a companion paper that focuses on the comparison of reactivity initiated events in CANDU with some other internationally accepted LWR reactor designs

Why nuclear energy is essential to reduce anthropogenic greenhouse gas emission rates

Reduction of anthropogenic greenhouse gas emissions is advocated by the Intergovernmental Panel on Climate Change. To achieve this target, countries have opted for renewable energy sources, primarily wind and solar. These renewables will be unable to supply the needed large quantities of energy to run industrial societies sustainably, economically and reliably because they are inherently intermittent, depending on flexible backup power or on energy storage for delivery of base-load quantities of electrical energy. The backup power is derived in most cases from combustion of natural gas. Intermittent energy sources, if used in this way, do not meet the requirements of sustainability, nor are they economically viable because they require redundant, under-utilized investment in capacity both for generation and for transmission. Because methane is a potent greenhouse gas, the equivalent carbon dioxide value of methane may cause gas-fired stations to emit more greenhouse gas than coal-fired plants of the same power for currently reported leakage rates of the natural gas. Likewise, intermittent wind/solar photovoltaic systems backed up by gas-fired power plants also release substantial amounts of carbon-dioxide-equivalent greenhouse gas to make such a combination environmentally unacceptable. In the long term, nuclear fission technology is the only known energy source that is capable of delivering the needed large quantities of energy safely, economically, reliably and in a sustainable way, both environmentally and as regards the available resource-base