Safety Upgrades’ Costs

The costs of safety upgrades have been considered in IAEA-TECDOC-1084 (1999). In this section, the costs for continued operation within the design life of the plant are considered specifically, costs associated with plant life extension (and decommissioning) are considered later in Chapter 6. It is also recognised that it is not usually possible to separate out from the available data, the costs associated with plant performance or for normal equipment replacement, against the costs associated with an actual safety upgrade.

In IAEA-TECDOC-1084 (1999), costs (levelised to 1997) associated with a range of water reactor types are reviewed. These include PWRs and BWRs from the US, Korea and Western Europe (Germany and The Netherlands) and Russian-designed VVER and RBMK plants in Central and Eastern Europe and the Russian Federation.

The cost estimates per unit of plant capacity and per year were considered for different categories of plant age (in 3-year period spans) for both PWRs and BWRs (Table 2.4). Costs over 5 years are also given to enable broad comparisons to be made against VVER and RBMK data covering costs of safety upgrades on these plants, carried out over the last few years. The average figure for BWRs was somewhat higher than PWRs (Table 2.4; IAEA-TECDOC-1084, 1999). However, it was concluded that the costs were not particularly reactor dependent.

It was also found that costs of upgrades depended on the age of the unit. In the first few years, costs were relatively high associated with bringing units up to latest regulations; this was followed by a period of lower costs; costs then started to rise as ageing factors start to become an issue.

Assessments for the Russian-designed VVER series were also carried out (IAEA — TECDOC-1084, 1999); reference data are shown in Table 2.5. The VVER-440/230 design

Table 2.4. US Safety upgrade costs ($US per kWe)

Plant

Estimated costs/year

Costs over 5 years

PWR

27

135

BWR

32

160

Data from IAEA-TECDOC-1084 (1999). Assumptions — average for different plant age categories.

Table 2.5. VVERs: Safety upgrade costs ($US per kWe)

Plant

Estimated costs

Generation of VVER

440/230

70-162

1st

440/213

23 -34

2nd

1000

17-31 (Russia)

3rd

201-277 (Ukraine)

Data from IAEA-TECDOC-1084 (1999).

has recognised deficiencies in relation to the integrity of the reactor vessel, the confinement pressurisation limit, and the limited scope of design basis accidents. The VVER-440/213 contains safety enhancements compared with the 440/230, particularly in terms of enhanced confinement capability, extended design basis for pipe breaks and more safety system equipment redundancy. This is reflected in the costs of the safety upgrades for VVER-440/213s, being 2-3 times lower than those for VVER-440/230s.

The VVER-1000s are better equipped again with a stronger containment. Additional enhancements have also been identified to achieve improvement of core behaviour and measures introduced to protect the integrity of the steam generators. Thus for VVER- 1000s, the costs are still relatively high. The Russian Federation estimates were much lower than the corresponding Bulgarian and Ukrainian estimates. It is worth noting that safety enhancements were implemented earlier in the VVER-440s because of the perceived urgency. The modifications of the VVER-1000s were of lower priority.

Important areas for safety enhancements of RBMKs have been identified, e. g. reduction of positive steam reactivity coefficient and improvement of the scram systems. It is clear that RBMK reactors still require investment of at least the same order as other plants, although a large part of the investments has already been made. Data are shown in Table 2.6.

The OECD study concluded that a new nuclear plant is unlikely to be the cheapest option, but that existing nuclear power plants provided they were operated and well managed can have a clear economic advantage, because of their low marginal costs. An important factor for the economic equation is whether a plant can operate reliably and in a stable condition, i. e. achieve a high load factor. Efficiency and performance are considered in Chapter 4. The load factors of nuclear plants tend to be less than those of fossil fuel plants.

Table 2.6. RBMKs: Safety upgrade costs ($US per kWe)

Plant

Estimated costs

Comments

1000

38 -97 (Russia)

Investment already made

1500

76-125 (Lithuania)

Data from IAEA-TECDOC-1084 (1999).

The economic benefits of continued operation of the Magnox plants in the UK have been published (Mortin, 2000). The UK electricity market is de-regulated and the Magnox stations have to compete with the other electricity generators. The price for electricity in the UK market has also reduced in recent years. Nevertheless Magnox stations have continued to operate for many years and some will continue to do so for the next decade. In the main, Magnox stations have achieved very respectable load factors. Nevertheless, the marginal contribution from individual Magnox stations of the fuel purchase costs is substantial and stations are closing. Fuel costs are increasing as there is a diminishing requirement for metallic fuel, as more stations are shut down (Smitton, 1999, 2000; May, 2003).

However, in summary, there are economic benefits in continuing to operate many existing nuclear plants. At the present time, these benefits are being further realised with the help of good management providing efficient, cost effective measures for running and ensuring the safety of the plant.

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