# US 2008/0130818 A1 · Leak detection method for testing fuel rods of fuel assemblies of a boiling water reactor for leaks

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2008/0130818 A1
- Document ID: US20080130818A1
- Status: Published application
- Kind: A1
- Application number: 11/801,939
- Filed: 2007-05-11
- Published: 2008-06-05
- Earliest claimed: 2004-11-11
- Assignees: Areva Np
- Inventors: Markus Pulmanns; Richard Stark
- Web page: https://patentgrep.com/patent/US20080130818A1

## CPC

- G21C 17/04: Detecting burst slugs
- G21C 17/06: Devices or arrangements for monitoring or testing fuel or fuel elements outside the reactor core, e.g. for burn-up, for contamination (G21C17/08, G21C17/10 take precedence; detecting leaking fuel elements during reactor operation G21C17/04)
- G21C 17/07: Leak testing
- Y02E 30/30: Nuclear fission reactors
- G21C: NUCLEAR REACTORS (fusion reactors, hybrid fission-fusion reactors G21B; nuclear explosives G21J)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Fuel rods of fuel assemblies of a boiling water reactor are tested for leaks. A plurality of fuel assemblies are each arranged adjacent to one another in a cell of the upper core grid of the boiling water reactor. A hood is placed above the fuel assemblies of a plurality of cells, which form a division for simultaneously heating the fuel assemblies of this division. At least one water sample is taken from each cell of this division, and the water samples from a plurality of cells forming a group are combined and tested for the presence of radioactive fission products contained in the water sample. A plurality of groups are analyzed simultaneously and independently of one another in a number, which number corresponds to the number of groups, of measurement channels of an analysis device. Where a result of a group is positive, the water samples from the cells which are located in this group are fed separately to the analysis device and are analyzed separately in a corresponding number of measurement channels. Those fuel assemblies of a cell that are found positive are tested individually outside the hood.

## Claims

### Claim 1

A leak detection method for testing fuel rods of fuel assemblies of a boiling water reactor for leaks, wherein a plurality of fuel assemblies are arranged adjacent one another in a cell of an upper core grid of the boiling water reactor, the method which comprises the following method steps:
a) placing a hood above the fuel assemblies of a plurality of cells forming a division for simultaneously heating the fuel assemblies of the division;
b) taking at least one water sample from each cell of the division;
c) combining the water samples from a plurality of cells forming a group and testing the water samples for the presence of radioactive fission products contained therein;
d) simultaneously, and independently of one another, analyzing a plurality of groups in an equal number of groups of measurement channels of an analysis device;
e) on registering a positive result in a given group, separately feeding the water samples from the cells located in the given group to the analysis device and analyzing the water samples separately in a corresponding number of measurement channels; and
f) individually testing fuel assemblies of a cell that have been analyzed as positive outside the hood.

### Claim 2 (depends on 1)

The method according to claim 1, which comprises hydraulically separating the cells located under the hood from one another in a region of the hood and from the cells located outside the hood.

### Claim 3 (depends on 1)

The method according to claim 1, which comprises, once a given division has been analyzed, relocating the hood onto another division and carrying out the test of the individual fuel assemblies of a cell, if a cell has been found positive in the given division, simultaneously with testing the other division.

### Claim 4 (depends on 1)

The method according to claim 1, which comprises taking the samples from a cell through a number of intake lines, the number corresponding to a number of the fuel assemblies located in the cell, with each removal location thereof being assigned to one respective fuel assembly.

### Claim 5 (depends on 1)

The method according to claim 1, which comprises successively lifting those fuel assemblies of a cell that have been analyzed as positive from the core using a telescope mast of a fuel assembly handling machine into a lifted-up position, and taking water samples in the lifted-up position and analyzing the water samples.