RU2407083C1 - Method for long-term storage of waste nuclear fuel - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: for long-term storage of waste nuclear fuel in holders filled with water, arranged in water basin under beam ceiling by means of suspensions, support parts of holders are installed at the bottom of the water basin, and upper end surface of holders is arranged under beam ceiling with a gap of 100÷150 mm at density of arrangement of holders on the basis of 30÷50 holders per square metre of the basin bottom area.

EFFECT: high quality level of nuclear and environmental safety of storage of waste nuclear fuel in extreme conditions.

1 dwg

Description

The invention relates to the field of nuclear energy, in particular to storage facilities for spent nuclear fuel, and can be used in nuclear power plants and plants for the regeneration of spent nuclear fuel.

In the prior art, there are a large number of patents related to methods for storing spent nuclear fuel: RF patent No. 5003902 from 04.10.1992, G21F 9/10, RF patent No. 2034346 from 04.29.1992, G21F 9/10, RF patent No. 2084025 from 08/18/1993, G21F 9/10. In the aforementioned patents, spent nuclear fuel is placed in protective cases filled with demineralized water, which are then placed using hangers on the slit girder ceiling of the water basin (storage).

The closest analogue of the claimed invention is a technical solution according to the patent of the Russian Federation No. 2062516, G21F 9/22 from 03/12/1993. The said patent describes a spent nuclear fuel storage containing a water basin in which slit beam beams are installed with spent nuclear fuel canisters suspended on them. The storehouse is equipped with pendants with horizontal supports fixed at its ends, with the upper support placed on the beams, the lower under the beams, and pencil cases attached to the lower horizontal supports.

The disadvantages of the closest analogue are the mismatch with modern requirements of nuclear and environmental safety of spent nuclear fuel storage in extreme conditions.

The problem solved by the invention is to achieve a qualitatively higher level of nuclear and environmental safety of spent nuclear fuel storage in extreme conditions.

The essence of the invention lies in the fact that in the method of long-term storage of spent nuclear fuel in canisters filled with water, placed in the water pool under the girder by means of suspensions, it is proposed to install the supporting parts of the cans on the bottom of the pool, and the upper end of the canisters to be placed under the girder with a gap of 100 ÷ 150 mm with a density of pencil cases at the rate of 30 ÷ 50 pencil cases per square meter of the bottom of the pool.

The set of distinguishing features: the installation of pencil cases at the bottom of the pool under the beam with a gap of 100 ÷ 150 mm and a density of pencil cases at the rate of 30 ÷ 50 pencil cases per square meter of the bottom of the pool allows solving the most important task of ensuring radiation and environmental safety in extreme conditions. An increase in the loading density to the indicated value leads to a corresponding decrease in the volume of pool water. In extreme situations (earthquakes, shock waves, and other dynamic effects), as a result of which the roof of the storehouse may collapse on the pool beams, under the influence of the shock, the beams will bend to contact with the ends of the canisters. As a result, numerous additional supports from the canisters are formed, which will prevent damage to the beams and the chaotic fall of the canisters. The gap specified in the formula is established on the basis of technological conditions and the magnitude of the possible deflection of the beams without breaking them out of the fixing place. The density of the canisters is determined based on the requirements of the maximum load distribution on the bottom of the pool when the roof falls.

To illustrate the method, we give a general view of the storage in cross-section (see drawing), which includes canisters 4 with spent nuclear fuel filled with water placed in a water basin 1 on a beam ceiling 2 by means of suspensions 3. Moreover, the supporting parts of the canisters 4 are installed on the bottom of the water basin 1, and the upper parts of the canisters 4 are placed under the beam ceiling 2.

The claimed method is as follows. Cases 4 with spent nuclear fuel filled with water by means of suspensions 3 are placed on the beam ceiling 2 in the water pool 1. The supporting parts of the pencil cases 4 are installed on the bottom of the water pool 1, and the upper ends of the pencil cases 4 are placed under the beam ceiling 2 with a gap of 100 ÷ 150 mm . Cases 4 are installed so that their density is 30 ÷ 50 pieces per square meter of bottom area of the water basin 1.

Claims (1)

A method for long-term storage of spent nuclear fuel in canisters filled with water, placed in the water pool under the beam by means of suspensions, characterized in that the supporting parts of the canisters are installed on the bottom of the pool, and the upper end of the canisters is placed under the beam with a gap of 100 ÷ 150 mm at a density placement of pencil cases at the rate of 30 ÷ 50 pencil cases per square meter of the bottom of the pool.