CONDITIONS FOR MAXIMUM FUEL BURNUP IN A RBMK CHANNEL REACTOR WITHOUT A MODERATOR ARTICLES

The conditions for attaining an operating regime with maximum burnup of nuclear fuel are examined. This can be a regime with steady continuous reloadings with the reactor replenished with fuel whose heavy atoms contain close to 50% of the fissioning material with average content 25% and burnup 35‐50%. The possibility of improving the stability of the fuel elements with increasing cladding thickness and the role of different organs for compensating reactivity in a regime with steady continuous reloadings and maximum fuel burnup are examined. An assessement is made of the possibility of obtaining a negative or zero effect of reactivity with loss of coolant and developing nonproliferation measures. If it is assumed that there is no fundamental reason preventing the development of fuel elements and a reactor with maximum burnup of nuclear fuel, then it is of interest to analyze the conditions for and ways to approach such an operating regime because then the fuel cycle of the reactors can once again, and this time finally, become open, and the fuel component of the cost of energy will decrease because the number of fuel changes before the fuel is completely burned up will be smaller. In a RBMK type channel reactor with an interchannel moderator, this could be a regime with steady continuous reloadings where fuel whose heavy atoms contain a maximum of ~50‐100% fissioning material and fuel with the same content of fission products is off-loaded is loaded into the reactor. Under prolonged irradiation in a neutron field a gradually decreasing equilibrium amount of certain actinides ‐ isotopes of uranium, plutonium, americium, and others ‐ arises. These actinides are difficult to burnup completely. Let these isotopic limitations remain. We shall first strive to achieve 50% burnup. Aside from these problems, there are other problems and conditions. We shall touch upon the stability of the fuel elements, the possibilities for compensating high reactivity, the reactivity effects with loss of coolant, and nonproliferation of