IP-EUROTRANS DOMAIN 1 Design WP 1.5 Safety Assessment of the Transmutation System Design

May 22nd & 23rd 2007 Stockholm

EUROTRANS: WP 1.5

Task 1.5.4 Containment Assessment

IP-EUROTRANSDOMAIN 1 Design

WP 1.5 Safety Assessment of the Transmutation System

Design


EUROTRANS: WP 1.5


Scope

EUROTRANS Detailed Implementation Plan 3rd DIP, WP1.5 objectives:Perform scoping assessment of the source term and the containment and to determine if there are no show-stoppers

EUROTRANS Detailed Implementation Plan 3rd DIP, Task 1.5.4: “This task is concerned with the analysis of the integrity of the containment and its leak tightness to keep any fission products released from the vessel from escaping the containment. The adequacy of the containment systems proposed by the designers will be addressed by assessing thermal and pressure loading of the containment due to release of coolant and melt from the vessel. LWR containment codes may be modified for this purpose. Transport of the fission product and polonium compounds in the containment will also be considered”.


EUROTRANS: WP 1.5


ADS Safety Barriers•For fission products:

•Fuel cladding

•Primary coolant boundary

•Containment

•For spallation products:

•Target boundary

•Accelerator isolation/Primary coolant boundary

•Containment


EUROTRANS: WP 1.5


The Containment System Safety Functions:

• fission product confinement and control

• protection against external events

• biological shielding


EUROTRANS: WP 1.5


Fission product confinement and control•Limitation of radionuclide releases

•Fission and spallation product removal mechanisms

•containment isolation

•leak tightness

•Containment integrity

•structural behaviour

•energy management system


EUROTRANS: WP 1.5


Fission and spallation product removal mechanisms

•Definition of radioactive products liberation to containment in different DBC

and DEC

•Special care with the consideration of severe accident conditions

•Identification of the need for radioactive products removal means


EUROTRANS: WP 1.5


Containment isolation:

Containment isolation provisions shall be designed to assure that fluid lines which penetrate the Primary Containment boundary are isolated in the event of DBC or DECs, so as to minimise the release of radioactivity to the environment. Also applicable to accelerator tube.

Leak tightness:

Containment shall be designed leaktight with a maximum leak rate compatible with dose limits considering design pressure.


EUROTRANS: WP 1.5


Energy management system.Heat removal from damaged fuel and containment.

Severe accident DEC with core damage.

Identification of fuel damage sequences

Possible need of a heat removal system from the containment after core damage.


EUROTRANS: WP 1.5


Structural Behaviour

The Primary Containment structure shall be designed to assure adequate performance in all plant conditions considered in the design process and specifically in DBC, testing, and DEC.


EUROTRANS: WP 1.5


Protection against external hazards

Natural external hazards

The Containment System structures shall be designed to cope with the natural Hazards, including earthquakes.

Man- made external hazards

The Containment System shall be designed to cope with man- made external hazards without loss of its structural integrity.An aircraft crash will not prevent reactor safe shutdown. Therefore no significant release of fission products will occur inside the containment and two Barriers will be assured even if the containment design leakrate cannot be proven under these conditions.


EUROTRANS: WP 1.5


Biological shielding

The Containment System shall be designed to limit, in all plant conditions, the exposure of on- site personnel and population to radiation generated by the primary circuit and associated systems.This function is accomplished mainly by concrete structures inside the Primary Containment and the containment concrete wall.


EUROTRANS: WP 1.5


Subtasks definitionConditions associated to representative events analysed

(DBC and DEC)•Subtask 1.5.4.1a Evaluation of analysed representative events in relation to any sequences that may imply radioactive releases and/or release of mass and energy from the reactor vessel or from other related systems, such as steam or feedwater pipe ruptures•Subtask 1.5.4.1b Identification of potential severe accident scenarios and definition of associated conditions related to containment/confinement requirements•Subtask 1.5.4.1c Evaluation of possible hydrogen generation and the eventual possibility of reaching explosive concentrations depending on the hydrogen mass generated and the free volume of locations in which it can accumulate. •Subtask 1.5.4.1d Based on the above results, a list of potential initiators and accident/release sequences including the associated mass and energy release estimate will be elaborated under this subtask.


EUROTRANS: WP 1.5


Subtasks definitionSource Term Behaviour

•Subtask 1.5.4.2a Bounding definition of potential releases to the containment and its behaviour on the basis of the different source term information available from Work Package 1.5.3 and the above analyses•Subtask 1.5.4.2b Fission products and Polonium transport mechanism will also be evaluated.•Subtask 1.5.4.2c The potential dose to the operators and the environment from the above source terms will be calculated.•Subtask 1.5.4.2d Recommendations, if required, for radioactive and fission product removal will be analysed.


EUROTRANS: WP 1.5


Subtasks definitionContainment Requirements for the XT-ADS and EFIT

Designs•Subtask 1.5.4.3a Evaluation of containment function performance requirements for both designs, based on the data gathered from the above activities and WP 1.2 results

•Subtask 1.5.4.3b Evaluation of containment function taking into account the main features related to the following:

Limitation of radionuclide releases (confinement function)

Containment integrity

•Subtask 1.5.4.3c Evaluation of other features such as protection against external hazards, HVAC/Filtering requirements or biological shielding

•Subtask 1.5.4.3d Consideration of specific conditions that may be imposed on containment and confinement requirements


EUROTRANS: WP 1.5


Subtask Responsibilities

The Task Partners are: KTH, FZK and EA

The following split of responsibilities for the elaboration of Task 1.5.4 deliverables is proposed:

Subtask 1.5.4.1a FZK

Subtask 1.5.4.1b KTH

Subtask 1.5.4.1c KTH

Subtask 1.5.4.1d EA

Subtask 1.5.4.2a FZK/KTH

Subtask 1.5.4.2b FZK/KTH

Subtask 1.5.4.2c EA

Subtask 1.5.4.3a EA

Subtask 1.5.4.3b EA

Subtask 1.5.4.3c EA

Subtask 1.5.4.3d EA


EUROTRANS: WP 1.5


Deliverables to be issued under this Task:

D1.63 Report on Containment Assessment for XT-ADSMonth 40

D1.65 Report on Containment Assessment for lead cooled EFITMonth 40

Related Source Term reports:

D1.62 Report on Source Term Assessment for XT-ADS

Month 33

D1.64 Report on Source Term Assessment for EFIT

Month 39

Convenient to have some preliminary information on source term in advance to start bounding dose calculations


EUROTRANS: WP 1.5


The following index, and input elaboration of responsibilities, is proposed for the Deliverables of this Task

Deliverable Chapter

1 Introduction and Purpose

2 General Safety Criteria. Containment Criteria

3 General Functions of the Containment

4 Barriers Against the Release Of Radioactive Products

5 DBC. Containment Design Requirements

6 DEC. Containment Design Requirements

7 Source Term Behaviour

8 Summary of Containment Design Requirements

Responsible

EA

EA

EA

EA

ALL

KTH/FZK

KTH/FZK

EA


EUROTRANS: WP 1.5


Budget

The assigned total budget allocation for Task 1.5.4 is as follows:

EA 4 m/m

FZK 4 m/m

KTH 4 m/m

Documents

IP-EUROTRANS DOMAIN 1 Design WP 1.5 Safety Assessment of the Transmutation System Design