Decommissioning and dismantlement of the Stade nuclear power ...

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Decommissioning and dismantlement of the Stade nuclear power ...

Decommissioning and dismantlement of the Stade nuclear power plant –

from nuclear power plant to green fields

Stade


Contents

3|The Stade nuclear power station – a short history

4|What does ”decommissioning and dismantlement

actually mean?

5|Why is the Stade plant being decommissioned?

Commercial factors

6|What experience do we have when

it comes to decommissioning nuclear power stations?

Dismantlement methods

Expertise that’s based on experience

Decommissioned and dismantled nuclear power stations in Germany

Reactor types

The Stade nuclear power station: special features

12 | What, exactly, does the dismantling process involve?

From full-load operation to decommissioning:

The transition phase:

Dismantlement Phases I - IV

Conventional dismantling

Timeframe

20 | What does decommissioning mean for Stade’s

employees?

Different workforce structures required

Staffing cutbacks

22 | What happens to the dismantled parts and materials?

Disposal methods

Waste material categories

Mechanical breakdown of materials

Decontamination

Safety clearance

Radioactive waste

28 | What happens to the vacant site?

Green fields

30 | What is the regulatory environment under which

decommissioning is performed?

Statutes and regulations

Clearance procedures

Environmental impact analysis

32 | The Stade nuclear power station in brief


The Stade nuclear power station – a short history

July 28, 1967 Nordwestdeutsche Kraftwerke AG applies for a government permit

to build and operate a nuclear power station near the German city of Stade

October 1967 Siemens AG is awarded the contract to build a turnkey nuclear power station

November 17, 1967 Permit for earthworks granted; construction works begin

March 1968 Plant operating company Kernkraftwerk Stade GmbH established

June 1971 Non-nuclear plant and equipment commissioned

January 7, 1972 Permit granted for commissioning of nuclear plant and equipment

January 8, 1972 Reactor attains first criticality

January 29, 1972 Stade begins to feed electricity into the public grid

March 26, 1972 First test at full load

May 19, 1972 Official hand-over to Kernkraftwerk Stade GmbH and start of commercial

on-load operation

1984 Stade starts cogenerating process heat for a neighboring salt works

Fall 2000 For commercial reasons, E.ON Kernkraft GmbH and HEW AG decide to

decommission and dismantle Stade, starting in the fall of 2003

July 2001 Application for permit for decommissioning and dismantlement (Phase I)

Fall 2001 Cumulative volume of electric energy generated since commissioning

totals 140,744 million kilowatt-hours

November 14, 2003 Reactor shutdown

2004 to 2008 Further applications for dismantlement permits (Phases II to IV)

End of 2014 Stade site released from Germany’s statutory nuclear facility

monitoring regime

By end of 2015 Conventional demolition of remaining building structures

3


Decommissioning in the broader sense

Decommissioning in the

narrow sense

_ permanent shutdown

of reactor

_ permanent shutdown

of remaining plant

What does “decommissioning and

dismantlement” actually mean?

Dismantlement

_ disassembly, decontamination,

and removal

from site of remaining

plant and materials

Decommissioning a nuclear power station means

shutting it down permanently.

Once it has been shut down, it is “dismantled,”

meaning it is gradually broken down into its constituent

parts. These parts then undergo different

types of treatment, depending on the level of

contamination, after which they are packaged and

removed from the site. Following dismantlement,

the site is completely cleared and made available

for unrestricted use.

The term “decommissioning” is often used more

loosely to describe everything that happens after

the plant is permanently taken offline, including

the shut-down and dismantlement processes.


Why is the Stade plant being decommissioned?

There are actually no technical reasons for decommissioning the Stade station at present.

The decision to decommission the facility was made exclusively on commercial grounds.

In July 2001, E.ON Kernkraft lodged an application for a permit for the initial dismantlement

phase, residual plant operations, and the construction of a temporary storage facility for the

radioactive waste from the dismantlement of the station’s nuclear plant and equipment.

Possible reasons for decommission nuclear power stations

political

_ nuclear exit strategy

agreement between the

German State and the

country’s energy industry

legal

_ Germany’s Atomic

Energy Act (AtG)

_ Germany’s Radiation

Protection Regulations

(StSV)

technical

Commercial factors

_ service life of key

components

As a result of electricity market liberalization,

Germany’s energy utilities are in the process of

downsizing both their conventional and nuclear

generation fleets in order to eliminate costly

excess generation capacity.

The Stade nuclear power station is no longer

economic. With a net installed capacity of 630 MW,

the facility delivers only about half the electric output

of most other German nuclear power stations,

but is equally if not more expensive to operate.

Another key factor in the decision to decommission

the station is the levy on water supplies

imposed by the government of Lower Saxony, the

German state in which Stade is located. The introduction

of this levy on water taken from the Elbe

River for plant cooling purposes resulted in some

8 million in additional costs for the Stade facility

per year.

In any event, the Stade facility would have

exhausted its residual generation quota – set

under Germany’s nuclear exit strategy – some time

in 2004. Thus, E.ON Kernkraft’s decision to decommission

the plant in 2003 cut short its service life by

only about one year.

commercial

_ excess generation

capacity

_ liberalized energy market

_ government levies on

supplies of cooling water

5


What experience do we have when it comes to

decommissioning nuclear power stations?

Germany’s original decision to use nuclear energy

for commercial electric generation came only after

considerable research on radioactive materials and

testing of various types of nuclear reactor. Dealing

with radioactive buildings, machines, installations,

and assemblies is therefore nothing new for

Germany’s nuclear energy industry.

Several nuclear power station decommissioning

projects have already been authorized and completed

in Germany, allowing the relevant energy companies

to trial a wide range of methods and processes.

The local industry also benefits from the decommissioning

expertise gathered by other countries.


Dismantlement methods

Germany’s nuclear power station operators carried

out a number of conceptual studies on decommissioning

nuclear power stations as early as the mid-

1970’s. These studies developed and compared two

decommissioning methods: dismantlement after a

period of safe enclosure (SAFESTOR) and immediate

dismantlement (DECON).

The first of these two methods involves dismantling

the facility after several decades of safe enclosure.

The enclosure period allows the radioactivity

to decay, so that dismantling can take place under

lower levels of radioactive exposure.

As the term suggests, immediate dismantlement

involves dismantling the plant as soon as it is taken

out of service. The advantage of this method is that

the plant’s existing technical systems can be used for

pre-dismantlement work such as decontamination.

Hybrid dismantlement methods can also be used –

such as enclosing only certain parts of the plant,

while dismantling the rest immediately.

Decommissioning nuclear power stations

Implementation of safe

enclosure measures

Safe enclosure period

(about 30 years)

Dismantlement

On-load operation

Transition phase

Immediate dismantlement

7


8

Expertise that’s based on experience

Germany’s nuclear energy industry has already permanently decommissioned

several nuclear power stations, including two where the sites have already been

returned to ‘green fields’. The map on the page opposite provides an overview

of Germany’s nuclear station decommissioning and dismantlement projects.

Facilities that have been fully dismantled are marked in blue.

Dismantling in progress

at the Würgassen plant

The Würgassen dismantlement project again highlights

the fact that the immediate dismantlement

method does not pose any great challenges.

This tried and proven process was selected for the

Stade facility because it retains jobs and therefore

also plant-specific expertise which helps to expedite

the dismantlement process.

One key difference between the Würgassen

and Stade facilities is that the former uses a boiling

water reactor (BWR), whereas the latter uses a pressurized

water reactor (PWR). The implications of this

in terms of the dismantlement process are explained

on the following pages.


Decommissioned and dismantled nuclear power stations in Germany

THTR-300 Hamm-Uentrop

(thorium high

temperature reactor)

Mülheim-Kärlich Nuclear Power Station

(PWR)

Lingen Nuclear Power Station

(BWR)

AVR-Versuchskraftwerk Jülich facility

(experimental high temperature reactor)

Karlsruhe MZFR Multipurpose

Research Reactor

(PWR)

fully dismantled facility

decommissioned facility

Stade Nuclear Power Station

(PWR)

Würgassen Nuclear Power Station

(BWR) – owned by E.ON Kernkraft

Kahl Nuclear Power Station

(BWR)

Großwelzheim facility

(superheated steam reactor)

Compact Sodium-Cooled

Nuclear Reactor I/II (KNK), Karlsruhe

Grundremmingen A

Nuclear Power Station

(BWR)

Greifswald Nuclear Power Station

(PWR)

Rheinsberg Nuclear Power Station

(PWR)

Niederaichbach Nuclear Power Station

(heavy water reactor/HWR)

9


10

Reactor types

In PWR nuclear power stations, the reactor heats

water in a fully self-contained circuit known as

the primary cooling loop. A heat exchanger transfers

the heat energy in the primary cooling loop

to a secondary cooling loop, causing the water in

the secondary loop to evaporate. The steam thus

generated is then ducted to the turbines. In this

way, the turbines are kept separate from the primary

loop, which makes them significantly easier

and safer to handle.

In fact, the structural design of the entire

facility was based on the principle of isolating all

sections which could potentially get exposed to

radioactivity. Only the reactor building and the

reactor auxiliary building are located in what is

known as the radiation control area; the turbine

room, comprising the turbines and the generator,

are located outside of this area.

Radiation control areas

PWR plant

BWR plant

Radiation control area

The diagram below further illustrates the key

differ-ences between pressurized water reactors

(such as Stade) and boiling water reactors (such

as Würgassen). In BWR plants, the radiation control

area encompasses the entire block, including the

turbine room. In PWR plants like Stade, on the other

hand, the reactor building is clearly separated from

the turbine room.

1

1 2

2

1 Turbine room

2 Reactor building


The Stade nuclear power station:

special features

Stade was Germany’s very first purely commercial

nuclear power station to use PWR technology. Its installed

capacity is now about half that of its more

modern counterparts. However, when it was commissioned

it ranked as Germany’s highest-output PWR

nuclear power station.

In 1984, Stade also became Germany’s first nuclear

power station to cogenerate process heat. The heat,

which is supplied to a neighboring salt works, is generated

via a tertiary cooling loop. Extracting useable

steam in this manner raises the overall efficiency

of the plant.

Pressurized water reactor

1

2

3

1 Reactor pressure vessel

2 Primary coolant pump

3 Steam generator

4 Water separator and

reheater

1

3

10

4

11

9

10

4

9

5 Turbines

6 Generator

7 Transformer

8 Condenser

9 Heat exchanger

5

8

13

12

10 Feedheater

11 Feedwater pump

12 Cooling-water pump

13 Cooling-water filter

14 Cooling pond

6

7

14

11


What, exactly, does the dismantling process involve?

Dismantling a large-scale nuclear facility involves

the step-by-step removal of all plant components and

thus requires the same level of precision planning as

building one. The dismantling process also clearly

distinguishes between nuclear and non-nuclear plant

components.


Most plant components and systems that are

not exposed to nuclear radiation can be dismantled

and removed immediately after plant shutdown –

provided they are not required for the rest of the

dismantling process.

From full-load operation to

decommissioning: the transition phase

The changeover from normal, full-load operation

to the dismantlement phase requires a number of

important changes to the plant’s operating processes.

To ensure this happens efficiently and safely,

the dismantlement plan allows for a so-called transition

phase of about one and a half years. During this

period, preparations are made for the disassembly

and removal of plant components and systems,

covering the following areas in particular:

_ the removal of spent fuel rods from the site

_ system decontamination measures

_ the isolation and shut-down of systems that

are no longer required.

Dismantlement of the power station’s nuclear plant

components starts once the transition phase has

been completed and the permit for decommissioning

has been granted. At Stade, the dismantlement

process has been divided into four phases. Each of

these phases is subject to the government regulations

applicable at the time and the associated

approval procedures.

13


14

Dismantlement Phase I

1

2

1 Materials air lock and air recirculation unit

2 Flood tanks

During the first dismantlement phase the necessary

logistics systems are established within the radiation

control area and as many non-required nuclear

systems as possible are removed to create more

space for subsequent dismantling work. The dismantlement

of the larger plant components is also

planned at this time.

The diagram above shows some of the systems

that are dismantled and removed during

Dismantlement Phase I:

3

1

4

3 Control rod assembly

4 Pressurized water tanks

_ The flood tanks that feed the primary loop

during start-up and shut-down.

Dismantling these helps to create extra space

for the treatment and interim storage of waste

materials from the dismantlement process.

_ The control rod assembly.

The individual components making up this

assembly are also small and their dismantlement,

which frees up space in the reactor chamber,

is uncomplicated.

_ The pressurized emergency cooling tanks and

other nuclear-contaminated systems that are no

longer required for the subsequent dismantlement

work.

However, some non-nuclear plant components

such as the live-steam and feedwater systems,

the emergency diesel generator set, and turbine

and generator components are also disassembled

and removed during this period.


Dismantlement Phase II

1 Steam generator

2Primary coolant pipe system, including pumps

2

The second dismantlement phase focuses on the

larger nuclear plant components and involves

preparatory work followed by actual dismantlement

and removal.

The components concerned include the primary

coolant pipe system, including:

_ the pumps,

_ the steam generator.

1

The components shown in the diagram are examples

only; other contaminated components not shown in

the diagram are also removed during this phase.

15


16

Dismantlement Phase III

1 Concrete slab

2 Fuel racks

2

1

3

4

3Reactor pressure vessel

4 Concrete shielding

The third dismantlement phase involves dismantling

and removing the most contaminated nuclear plant

components. Neutrons escaping from the reactor have

made these components radioactive; they can not be

decontaminated. As highlighted in the diagram above,

these components include:

_ the reactor pressure vessel,

_ the concrete shielding that encloses the reactor

pressure vessel (known as the biological shield),

_ the overhead concrete slab that shields the reactor

room,

_ the fuel racks in the former fuel storage tank,

and various fixed and moveable pressure vessel

components.


Dismantlement Phase IV

1 Polar crane

2 Fuel transfer platform

2

1

3Ventilation plant

4Water purification plant

In the final nuclear dismantlement phase, all the

systems remaining in the radiation control area are

gradually dismantled and removed. The last systems

to be removed are the water purification and ventilation

plants.

The remaining building structures in the control

area are then cleaned and decontaminated so that

they meet statutory requirements for safety clearance.

The radiation control area is thus gradually

scaled down and eliminated.

3

4

17


18

Elbe River

The final stage involves all such site clearing and decontamination

work as is necessary to ensure the site meets statutory radiation safety

clearance requirements. Once this has been achieved, the site is released

from Germany’s statutory nuclear facility control and permit regime.

Conventional dismantling

Planned control area elimination process

Step 1

Containment

Step 2

Reactor building

Step 3

Auxiliary services building

Step 4

Entrance to radiation control area,

stack

The final step in dismantling the Stade plant

involves the demolition and removal of the remaining

buildings and structures from the site. Conventional

demolition methods can be used during this

phase because the site is no longer subject to statutory

nuclear facility control and permit requirements.

The scrap concrete and steel generated by the

demolition process is recycled wherever possible.

The decommissioning and dismantling project is

officially at an end once the site has been restored

to green fields.


Timeframe

When the Stade nuclear power station was shut

down on November 14, 2003, preparations for the

plant’s subsequent dismantlement were already

well underway.

The current transition phase, which began after

shutdown, involves the removal of the remaining fuel

rods. Once this is done, deconstruction can begin in

accordance with the statutory regulations governing

the initial dismantlement phase. We estimate this

will happen midway through 2005.

The dismantling of the plant and installations

in the radiation control area will take place in four

phases, as described earlier. This process is expected

to take almost ten years and will therefore probably

not be completed until the end of 2014. The only

task remaining once the site has been released

from Germany’s statutory nuclear facility control

and permit regime is to demolish the buildings and

structures. This is scheduled to take place in 2015.

The phases described above are independent of

each other and can therefore overlap. The permit

application for Phase I was lodged in July 2001.

Permit applications will be lodged in good time for

the scheduled start of each of the remaining phases.

Decommissioning timetable

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

On-load operation

Transition

phase

Construction

Residual operation (immediate dismantlement)

Dismantlement of non-nuclear components

Dismantlement of nuclear components

Phase I

Operation

Phase II

Phase III

Storage facility for radioactive waste

Phase IV

Building

demolition

19


What does decommissioning mean for Stade’s employees?


Different workforce structures required

Compared to daily production operations, plant

decommissioning involves fundamentally different

work processes. This has important implications for

the plant’s organizational structures as well as the

makeup and size of its workforce.

The primary focus during the Stade facility’s

service life was on ensuring safe, reliable plant operation.

Now that the facility is being decommissioned,

its safety systems and installations will gradually be

taken out of service. Naturally, this will also impact

the employees who are working in this area.

However, decommissioning also brings with it new

task areas and responsibilities. For example, it will

create opportunities for employees who are skilled

in the use of the dismantling equipment. We will

also need additional radiation protection specialists.

However, over the long term there will be a net

decline in employee numbers.

Staffing cutbacks

E.ON Kernkraft GmbH has a twofold strategy for

minimizing the impact of anticipated job losses.

Our older employees, including those who reach

the required age before the end of the dismantling

project, have the opportunity to participate in a

special early retirement program. Exempt from this

are those older staff members who possess skills

that are essential for the dismantling project.

The second strategy relates to the redeployment

of personnel to other E.ON Kernkraft locations. Those

affected will need to relocate and, in all probability,

retrain. This option will most likely be more attractive

to the company’s younger employees.

21


What happens to the dismantled parts and materials?

Waste material

from the radiation

control area

Various measurements, tests, and treatment processes

Safety clearance

as re-usable/recyclable

waste or conventionalnon-recyclable

waste

Controlled re-use Radioactive waste

By far most of the material resulting from the

dismantlement process is not radioactively contaminated

and can therefore be treated like normal concrete

and steel demolition waste. This includes the

material removed from the radioactive control area.

However, because of the risk that material from the

control area may be contaminated, all components

from this area need to undergo rigorous testing.

Once testing is complete, the disposal technicians

individually determine how each component is to

be disposed of.

Material that is neither contaminated nor radioactive

may be suitable for immediate re-use or recycling

in other areas. For example, the waste concrete

from the building demolition process counts is standard

building rubble and can be re-used in the construction

industry. Most of the metal components are

recyclable scrap metal. The diagram below shows the

main disposal methods for the waste material from

the radiation control area.


Disposal methods

There are a range of disposal methods for the

waste material from the radiation control area.

These include:

_ unrestricted safety clearance for re-use or

recycling

_ scrap metal: safety clearance for recycling subject

to certain conditions

_ safety clearance for disposal as conventional,

non-recyclable waste (for landfills)

_ controlled re-use by the nuclear industry

_ safe disposal as radioactive waste

The materials are classified into the above clearance

categories in accordance with the rules and

radiation exposure limit values laid down in

Germany’s Radiation Protection Regulations (StSV).

Each control area component is tested to determine

its contamination or radioactivity status, classified,

and assigned an appropriate disposal method.

Each component is then disassembled and/or broken

down and, where applicable, decontaminated so that

it meets the requirements of the selected disposal

method.

Dismantling work in progress at

the Würgassen NPP

23


24

Plant dismantlement:

waste material categories

Based on its experience of past decommissioning

projects and its intimate knowledge of the Stade

facility, E.ON Kernkraft GmbH is able to estimate

with considerable accuracy the volume and percentages

of materials that will be allocated to each

clearance category, as shown in the chart below.

Materials categories: percentages and volumes

Area

in Mg (megagrams)

Clearance

(restricted and

unrestricted)

272,100 Mg

Non-nuclear

area

127,540 Mg

Nuclear

area

Controlled

re-use

Detailed view:

Nuclear area

Radioactive

waste

97,2 % Safety

clearance

0,4 % Controlled

re-use

2,4 % Radioactive

waste

Nuclear area 124,005 (97.2 %) 545 (0.4 %) 2,990 (2.4 %) 127,540 (100 %)

Non-nuclear area 272,100 - - 272,100

Total 396,105 545 2,990 399,640

Total


Mechanical breakdown of materials

During the dismantlement process large plant

components need to be cut up into smaller sections.

Conventional tools such as large blade saws, hydraulic

shears, cutting torches, and metal shredders are

used for this purpose. Slow-running machinery is

employed wherever possible to prevent the creation

of aerosols.

The tools and equipment are set up in the

necessary configuration in the areas designated for

dismantling/cutting, decontamination, and waste

treatment. Minimizing the decommissioning personnel’s

exposure to radiation is the paramount criterion

for selecting which tools and methods to use.

The work processes are also designed to prevent

the buildup of dust and grime. Certain processes are

even performed in sealed areas with their own, separate

air handling systems or in containers. In these

areas, the air is extracted and filtered, thereby preventing

the spread of radioactivity within the plant

and protecting the environment from radioactive

emissions.

Wherever possible, the plant components are

broken down into pieces small enough to fit into

special containers, which are then transported to

further treatment stations. After disassembly and

cutting, each item is thoroughly cleaned. Extremely

sensitive measuring instruments are then used to

determine each item’s level of radioactivity or surface

contamination. Depending on the outcome of these

measurements, each item is either submitted for

final clearance testing or is first decontaminated

and then submitted for final clearance testing.

Decontamination

In most cases, radioactivity is confined to mere

surface contamination. When the Stade plant was

built, many of the components used were coated

with a special sealant designed to facilitate decontamination.

These types of components can in most

cases be completely decontaminated by thorough

washing or abrasion. Where contamination has penetrated

deep into the material via cracks and pores it

is removed by mechanical or chemical means.

The following decontamination methods are used:

_ steel grit blasting,

_ water blasting, and

_ chemical flushing.

Dry steel grit blasting is a highly effective decontamination

method for disassembled and cut-up components

with readily accessible surfaces. It involves

grinding the surface off the components by bombarding

them with a jet of pin-head-sized steel

grains traveling at nearly the speed of sound.

Chemical flushing, on the other hand, is used for

decontaminating whole systems and assemblies prior

to disassembly. The final decontamination step is a

simple matter of isolating the contaminated particles

from the steel grit or chemical solution.

Decontamination keeps the volume of secondary

radioactive waste to an absolute minimum and significantly

reduces the amount of radiation to which

the plant’s personnel are exposed during subsequent

dismantling work. The decontamination methods

used are specially tailored to the method of disposal.

25


26

Safety clearance

The material from the dismantlement process must

meet extremely stringent standards to qualify for

unrestricted clearance for conventional recycling or

re-use. This involves subjecting it to a series of tests:

Following preliminary testing for the presence of

radioactivity, disassembly and dismembering, and

decontamination, the material is subjected to socalled

orientation testing. This entails direct measurements

of surface contamination, the primary aim of

which is to determine the distribution of radioactivity

across the surfaces.

Final clearance testing is designed to determine

whether the material meets statutory requirements

for clearance. It involves a range of different measurement

and testing methods, which are also subject

to differing requirements in terms of radioactivity

distribution and are thus closely associated with

orientation testing.

Under certain conditions the power plant operator

will also conduct so-called control measurements.

These involve both direct measurements and the

taking of samples for laboratory analysis.

Once all the tests and measurements have been

performed, the complete set of clearance documents

is submitted to the competent statutory atomic energy

regulatory body. The material can only be removed

from the plant site after this body has given its

approval and the plant’s designated radiation protection

officer has issued final safety clearance.

The clearance process

Disassembly, dismembering

Decontamination

Preliminary/

orientation testing

Final clearance testing

Control testing

Final clearance


Radioactive waste

E.ON Kernkraft plans to construct a storage facility

for radioactive waste during the post-shutdown transitional

phase. The facility will be located adjacent to

the Stade site and will be used exclusively to house

radioactive waste from the operation and dismantlement

of the Stade nuclear power station. Only low

and medium-level radioactive waste will be stored

in the facility; the fuel elements will be transported

off-site prior to the start of dismantling work.

The storage facility will have a service life of

40 years, and is intended for temporary storage until

Germany’s federal government provides a final storage

facility. However, the waste will be placed in the

temporary facility in a form suitable for final storage.

11

2

4

5

Elbe River

1

10

8

9

6

3

7

1 Reactor building

2 Reactor auxiliary building

and annexes

3 Aftercooling system building

4 Switchgear building

5 Turbine room

6 Control building

7 Office and employee services

building

8 Workshop and storage area

9 Emergency diesel generating

sets

10 Transformers

11 Planned temporary storage

facility for radioactive waste

27


What happens to the vacant site?


Green fields

In Germany two nuclear power station sites have

already been returned to ‘green fields.’ Broadly

speaking, the land on which the power plants were

once located has been returned to nature: it has

been replanted and is now lying fellow. The Stade

site will also be restored to green fields. At this

stage it has not been decided if and to what extent

the land will be put to other industrial uses.

29


What is the regulatory environment under which

decommissioning is performed?

Statues and regulations

In Germany the construction, operation, and decommissioning

of nuclear power stations is governed by

the Atomic Energy Act (AtG). The decommissioning

and dismantlement of nuclear facilities is also subject

to numerous statutory and administrative regulations.

The regulatory framework includes the Radiation

Protection Regulations (StSV), the Recycling and

Waste Management Act (KrW-/AbfG ), the Hazardous

Substances Regulations (GefStoffV), and the Federal

Pollution Control Act (BimSchG).


The permit process

Permit application

Permitting authority

(highest competent

authority at state level)

Decision

Clearance procedures

Permanent nuclear power station decommissioning

and safe enclosure require permits issued in accordance

with the Atomic Energy Act (AtG) by the highest

competent state-level authority. Accordingly,

E.ON Kernkraft GmbH has applied to Germany’s

Lower Saxony State Ministry for the Environment

for a permit to decommission and dismantle the

Stade nuclear power station.

The diagram above shows the role of the various

government bodies and institutions in the permit

process.

Additional reports

Participating government agencies

General public

Expert report

Federal Ministry for the Environment,

Conservation and Reactor Safety (BMU)

Participating federal

agencies

Environmental impact analysis

An environmental impact analysis must be performed

before the Stade nuclear power station decommissioning

project can proceed. The analysis must cover

all aspects of the project, including the proposed construction

of a temporary storage facility for radioactive

waste from the operation and dismantlement of

the plant. Its purpose is to ascertain and assess the

project’s environmental impacts. The environmental

impact analysis is thus an integral part of the permit

process.

31

Reactor Safety Commission

Radiation Protection Commission


32

The Stade nuclear power station in brief

Stade nuclear power station

Technical data

Reactor type BWR

Net installed capacity 630 MW

Start of commercial on-load operation May 19, 1972

Nuclear plant

Reactor pressure vessel

Rated pressure (positive) 175 bar

Internal diameter 4,080 mm

Overall height 10,400 mm

Cylinder section wall thickness plus plating 192 + 7 mm

Total weight 270 t

Reactor core

Number of fuel elements 157

Total uranium weight 56 t

Number of control rods 49

Steam generators

Number 4

Steam output per unit 898.1 t/h

Output steam pressure 52 bar

Output steam temperature 265 °C

Reactor cooling system

Number of coolant pumps 4

Average coolant temperature 298 °C

Containment

Ball diameter 48 m

Rated pressure (positive) 3.8 bar

Wall thickness 25-35 mm

Turbine room systems

Turbines and condenser

High-pressure turbine 1

Low pressure turbine 2

Speed 1,500 min –1

Heat rise of cooling water in condenser 9 K

Generator

Output 780 MVA

Transformer voltage 21 kV

Power factor (cos phi) 0.85

Unit transformers

Number 2

Output per unit 380 MVA

Frequency 50 Hz

Cogeneration system

Tertiary loop steam volume 60 t/h, corresp. to 7.7 MW

Steam pressure 10 bar

Steam temperature 190°C

Condensate pipeline 1.5 km to salt works

Located on the banks of the Elbe River,

the Stade nuclear power station was commissioned

in 1972. It has been cogenerating

process heat for a neighboring salt

works since 1984.

The Stade plant is two-thirds owned

by E.ON Kernkraft GmbH. The remaining

one-third stake is owned by Vattenfall

Europe AG.


Publisher

E.ON Kernkraft GmbH

Corporate Communications

Tresckowstraße 5

30457 Hannover

Germany

Editor

Kernkraftwerk Stade

Public Relations

Photographs

Peter Hamel

Volkmar Gawehn, Isernhagen (page 2)

Zefa, Hamburg (page 29)

Archivberlin, Berlin (page 30)

Translation

Anglobe Business Services,

Hamburg

Design

Maurer Werbeagentur,

Hannover

Printer

Gesellschaft für Digital- und

Printmedien mbH, Hannover

Edition 6/2004

All rights reserved. No part of

this document may be reproduced

without the Editor’s permission.


E.ON Kernkraft GmbH PO Box 4849 30048 Hannover Germany

Tresckowstraße 5 30457 Hannover Germany

T +49 (0)5 11-4 39 03 F +49 (0)5 11-4 39 23 75

www.eon-kernkraft.com www.eon.com

Stade Nuclear Power Plant Bassenflether Chaussee 21723 Stade Germany

T +49 (0)41 41-77 23 91 F +49 (0)41 41-79 93 04

E.ON Kernkraft GmbH Corporate Communications

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