Venting system for the containment of a nuclear plant and method of operating the venting system

Patent metadata

Field	Value
Publication number	US-2016019986-A1
Application number	US-201514867197-A
Country	US
Kind code	A1
Filing date	Sep 28, 2015
Priority date	Mar 27, 2013
Publication date	Jan 21, 2016
Grant date	—

Abstract

A pressure-relief system for a containment of a nuclear plant has a pressure-relief line which is led through the containment and is closed by a shutoff device, and a wet scrubber being switched into the pressure-relief line lying outside the containment, for the pressure-relief gas flow developing in the pressure-relief operating mode with the shutoff device being open. An effective, reliable operation of the wet scrubber with a compact structural configuration is made possible. This is achieved by a reservoir, arranged in the containment or fluidically connected therewith such that an overpressure, as compared with the outer environment, present in the containment, is transferred to the reservoir, and a feeding line which is led from the reservoir to the wet scrubber and can be closed by a shutoff device, for feeding a liquid active as a scrubbing liquid from the reservoir to the wet scrubber.

First claim

1 . A pressure-relief system for a containment of a nuclear plant, the pressure-relief system comprising:
a shutoff device; a pressure-relief line being led through the containment and being closed by said shutoff device; a wet scrubber being switched into a section of said pressure-relief line lying outside the containment, for a pressure-relief gas flow developing in a pressure-relief operating mode with said shutoff device being open; a reservoir disposed in the containment or fluidically connected therewith in such a way that an overpressure, as compared with an outer environment, present in the containment, is transferred to said reservoir at least partially; a further shutoff device; and a feeding line leading from said reservoir to said wet scrubber and being closed by said further shutoff device, for feeding a liquid active as a scrubbing liquid from said reservoir to said wet scrubber.

2 . The pressure-relief system according to claim 1 , wherein said reservoir has a condensation chamber.

3 . The pressure-relief system according to claim 1 , wherein said reservoir is a pool, a pressure of said pool is equalized with respect to a rest of the containment.

4 . The pressure-relief system according to claim 1 , wherein:
said wet scrubber contains a washing liquid tank which is sealed with respect to a rest of an inner chamber of the containment; and said pressure-relief line having a throttle portion disposed upstream of a point at which said pressure-relief line passes into said washing liquid tank.

5 . The pressure-relief system according to claim 4 , wherein said throttle portion is configured such that, at a start of a pressure-relief process, said shut-off device in said pressure-relief line being open and a pressure inside the containment being at least 2 bar absolute, a pressure inside said washing liquid tank is reduced by comparison by at least 0.3 bar.

6 . The pressure-relief system according to claim 4 , further comprising a fill-level control, formed by a float valve inside said washing liquid tank, for the scrubbing liquid fed in via said feeding line.

7 . The pressure-relief system according to claim 4 , wherein said wet scrubber is a Venturi scrubber having a Venturi tube disposed in said washing liquid tank and at a neck portion of said Venturi tube there is an intake opening formed therein for Venturi injection of the scrubbing liquid into the pressure-relief gas flow.

8 . The pressure-relief system according to claim 7 , further comprising a pool for the scrubbing liquid disposed inside said washing liquid tank and encloses said intake opening in said Venturi tube, a capacity of said pool is substantially less than a capacity of said washing liquid tank.

9 . The pressure-relief system according to claim 1 , further comprising a throttle device disposed in said pressure-relief line downstream of said wet scrubber when viewed in a flow direction of the pressure-relief gas flow, said throttle device configured for critical pressure relief of the pressure-relief gas flow.

10 . The pressure-relief system according to claim 1 , wherein said wet scrubber is dry when in a standby mode.

11 . The pressure-relief system according to claim 1 , further comprising a drainage and residual heat removal system connected to said reservoir.

12 . The pressure-relief system according to claim 3 , wherein said a pool is an open pool.

13 . The pressure-relief system according to claim 4 , wherein said throttle portion is configured such that, at a start of a pressure-relief process, said shut-off device in said pressure-relief line being open and a pressure inside the containment being at least 4 bar absolute, a pressure inside said washing liquid tank is reduced by comparison by at least 1 bar.

14 . A nuclear plant, comprising:
a containment; and a pressure-relief system for said containment, said pressure-relief system containing:
a shutoff device;
a pressure-relief line being led through said containment and being closed by said shutoff device;
a wet scrubber being switched into a section of said pressure-relief line lying outside said containment, for a pressure-relief gas flow developing in a pressure-relief operating mode with said shutoff device being open;

a reservoir disposed in said containment or fluidically connected therewith in such a way that an overpressure, as compared with an outer environment, present in said containment, is transferred to said reservoir at least partially;
a further shutoff device; and
a feeding line leading from said reservoir to said wet scrubber and being closed by said further shutoff device, for feeding a liquid active as a scrubbing liquid from said reservoir to said wet scrubber.

15 . The nuclear plant according to claim 14 , wherein said nuclear plant is a boiling water reactor nuclear plant.

16 . A method for operating a pressure-relief system, the pressure-relief system containing:
a shutoff device;
a pressure-relief line being led through a containment and being closed by the shutoff device;
a wet scrubber being switched into a section of the pressure-relief line lying outside the containment, for a pressure-relief gas flow developing in a pressure-relief operating mode with the shutoff device being open;
a reservoir disposed in the containment or fluidically connected therewith in such a way that an overpressure, as compared with an outer environment, present in the containment, is transferred to the reservoir at least partially;
a further shutoff device; and
a feeding line leading from the reservoir to the wet scrubber and being closed by the further shutoff device, for feeding a liquid active as a scrubbing liquid from the reservoir to the wet scrubber;

which method comprises the steps of:
prior to or during a pressure-relief process, conveying the liquid from the reservoir into the wet scrubber, by means of the feeding line, as a result of a pressure difference between the containment and the wet scrubber.

17 . The method according to claim 16 , wherein, during an activation phase preceding the pressure-relief process, filling the wet scrubber for a first time by the further shut-off device in the feeding line being opened while the shut-off device in the pressure-relief line is closed.

18 . The method according to claim 16 , wherein, during the pressure-relief process, the shut-off device in the pressure-relief line being open and the shut-off device in the feeding line being open, used scrubbing liquid is fed back into the wet scrubber.

Assignees

• Areva Gmbh

Inventors

• Eckardt Bernd
• Losch Norbert
• Zehe Frank

Classifications

• G21C19/303

  specially adapted for gases (decontamination of gases G21F9/02) · CPC title

• G21C9/06

  Means for preventing accumulation of explosives gases, e.g. recombiners · CPC title

• G21F9/02

  Treating gases · CPC title

• G21C9/004 Primary

  Pressure suppression · CPC title

• G21D3/04

  Safety arrangements (emergency protection of reactor G21C9/00) · CPC title