**12. Conclusion**

214 Nuclear Power – Practical Aspects

much more than in cheap deposits.

0

1000000

2000000

3000000

**U & Th demand, tons**

4000000

5000000

Work duration of thermal reactors with cheap uranium stocks at this power level and full raw uranium usage is ~2500 years. It is understandable that at such small raw uranium requirements is rational use of other more expensive deposits, where uranium stocks are

Wmax = 8000 GWatt

**Figure 16.** Dependence of uranium and thorium requirements for different reactor types with zero initial power and its even increase up to level of 8000 GW with subsequent power level stabilization.

0 50 100 150 200 250 **Time, years**

U i=0.25 U i=1.0 Th U fast reactors

Nonproliferation regime in common case is supplied by IAEA control. With control the possibility of proliferation is limited by value less than detection error. The base of this error is inaccuracy of mass detection at chemical reprocessing of irradiated in core material.

For thermal reactor of 1000 MW requirement in 233U is about 10 kg per annum. Accordingly, in ideal case of reprocessing conducting, possible error in 233U is less than 10 g per annum. If inaccuracy of the error is 10 %, than proliferation is not much than 1 g per annum. For minimal warhead in this case is needed more than 1000 years. This term exceeds possible

**11. Comparison of possibilities of unauthorized fission materials** 

Typical value of the error can be in our case ~0.1 % from reprocessed mass of 233U.

**proliferation at different technologies of fuel cycles** 

duration not only a terrorist organization but even a terrorist state.

So, there is significant reserve in world nuclear power production industry.

Fission materials reproduction possibility in different fuel types in ideal core without neutron losses in construction materials and leakage is shown. Equilibrium concentrations of fission materials in different fuel types are determined.

Features of detailed regime campaign conduction (with fixed fuel location during all campaign) and compact regime (with staged spent fuel replacement with fresh fuel).

Characteristics of loss and reproduction in case of CANDU and its possible modernization variants are examined.

Replacement in zirconium containing materials natural zirconium by isotope 90Zr and natural tin by isotope 120Sn, replacement of 7 fuel rods in fuel assembly with 37 fuel rods by beryllium insert for extra neutron production, change of fuel rods with oxide fuel by metallic fuel is considered as possible modernization directions, which supply high fission materials reproduction.

Compound metallic fuel rod construction, placed in liquid metal heat transferring medium is suggested. Shape and small size of fuel rod ensure decrease of negative effect of swelling.

Possibility of neutron loss decrease in CANDU from 5% to 2.8% in case of isotope modified zirconium and tin and to 1.7% in case of metallic fuel and beryllium insert.

It is suggested that excess neutrons of detailed campaign beginning are used for fission materials reproduction. By the set of characteristics 233U is the best candidate for reproduction.

Portion of raw uranium use increase in open fuel cycle up to 5.3% and full raw uranium usage in closed uranium and thorium fuel cycles is shown.

Conditions of high efficiency obtaining in Rankin cycle with heavy water gas cooled reactor are shown. Scheme of coolant ducts and steam loop of heavy water channel reactor with gaseous coolant, which ensures full use of neutron moderation energy, decrease energy loss for coolant pumping and obtaining high steam quality on the turbine exit. These actions allow to decrease cost for NPP creation, to have efficiency of 43 % taking into account possible losses in core and steam cycle.

World nuclear power production industry creation with power of 8000GW to the end of XXI century on the base of suggested thermal reactors with high fission materials reproduction is shown.

Suggested technologies usage allows increasing world nuclear power industry to the end of XXI century with requirement decrease of natural uranium mining, proliferation danger decrease comparing to fast reactors technology.
