219atw Vol. 59 (2014) Issue 4 | April

Nuclear Power Plant Operation

EPZ and AREVA – A longstanding partner-ship for the safe and reliable operation of the Dutch Borssele Nuclear Power PlantYvonne Broy, Erlangen/Germany and Monique Linger, Borssele/The Netherlands

Addresses of the Authors:Yvonne Broy

AREVA GmbHPaul-Gossen Straße 100

91052 Erlangen/Germany

Monique LingerElektriciteits-Productiemaatschappij

Zuid-Nederland N.V.Zeedilk 32,

4454 PM Borssele The Netherlands

On October 26, 2013, Pressurized Wa-ter Reactor Nuclear Power Plant Borssele, the “Kerncentrale Borssele” (KCB), celebrat-ed its 40th anniversary of the beginning of commercial operation. On February 19th, 2014 EPZ received its irrevocable license for operation utill 2034. EPZ, AREVA and their respective predecessor companies have regularly implemented ambitious and technically challenging modernization projects since the plant went into opera-tion. This gave proof that maximum safety in a nuclear power plant can be ensured ir-respective of its date of construction. Re-cently, an independent commission of the Dutch government confirmed that even af-ter 40 operating years KCB belongs to the safest 25 per cent of all water-cooled nu-clear power plants within the European Union, US and Canada.

This makes KCB a leading example for projects aimed at extending the operating life of nuclear power plants. Most of the nuclear power plants worldwide are older than 25 years, every tenth plant is already

more than 40 years old. At the same time, many operators plan to modernize their plants and implement safety retrofits to re-ceive approval of the respective superviso-ry authority for a continuation of opera-tion. AREVA supports operators with its comprehensive competencies, not only based on its experience at Borssele but with other operators as well, and offers a whole catalogue of modernization measures for long-term operation: the so-called “For-ward Alliance Catalogue“. This comple-ments AREVA’s range of products for oper-ating nuclear power plants already docu-mented in the “Safety Alliance Catalogue”, which comprises offers in the field of safe-ty retrofits since 2011.

Placing of the order upon foundation of KWU – fundamental modernization in the 1990s

When the former Kraftwerk Union was set up in 1969, it won the contract to build the nuclear power plant in Borssele. In 1973, the 2 loop pressurized water reactor was connected to the grid with a net electric output of 449 megawatts. At first, the plant produced the power for an aluminum smelter facility located nearby, but since 1987 also for the general needs of the Netherlands.

The partnership between manufacturer and operator did not end with handing over the power plant. Both parties contin-ued to work together to continuously adapt the nuclear power plant to the state-of-the-art. A particular milestone was the funda-mental modernization of the plant in the 1990s under the so-called “MOD97“ pro-ject. At that time, all relevant parts of the piping system, the safety I&C and other equipment including the emergency diesel generators were replaced in approximately five months.

Moreover, the engineers of both compa-nies retrofitted safety systems newly devel-oped after the commissioning of the plant. This includes a Filtered Containment Vent-ing System (FCVS), which provides a fil-tered containment venting function in the case of a severe accident without any im-pact to the environment. Also Passive Au-tocatalytic Recombiners (PAR) that pre-vent accumulations of hydrogen in the  on-tainment by combining gas with atmos-pheric oxygen to make water were already retrofitted within the MOD97

Fig. 1. Pressurized Water Reactor Nuclear Power Plant Borssele in the Netherlands (at the right of the picture).

220 atw Vol. 59 (2014) Issue 4 | April

Nuclear Power Plant Operation

project. At the end of this modernization, Borssele Nuclear Power Plant had reached the safety level of the latest German Kon-voi plants which went into operation at the end of the 1980s.

In 2006, as part of a modernization of the turbine, the net electricial output of the plant was increased by about 10 per-cent to 485 megawatts.

AREVA makes Borssele fit for its long-term operation

KCB’s planned continuing of operation to 60 years was linked to strict requirements, especially with regard to the safety level by the Dutch policy and supervisory authori-ties. Apart from national and European law standards, the plant was subject to an intensive evaluation for long-term opera-tion by the IAEA (International Atomic En-ergy Agency), also called “SALTO Peer Re-view“.

EPZ decided to tackle this challenge with the support of its long-standing part-ner AREVA. The companies formed a pro-ject team of about 30 people, who pro-cessed the subprojects jointly. This includ-ed analyses regarding the safe operation of the reactor pressure vessel for a period of 60 years or the qualification of electro-technical components. A key module was the so-called “Ageing Management Re-view“ for the passive components in ma-chine technology, electrical and I&C sys-tems as well as construction engineering. The AREVA team, in close cooperation with EPZ, determined the extent to which safe-ty-relevant systems, structures and compo-nents are subject to wear. This can be achieved by non-destructive examina-tions,  recurrent testing, plant inspec-tions or analysis of water chemistry. Final-ly, recommendations for appropriate follow-up were derived from the final eval-uation.

Outlook: Digital safety and operational I&C in Borssele

Another milestone is coming up soon: The KCB safety I&C shall gradually be changed to digital technology in the next years. For this upgrade, AREVA offers its TELE-

PERM XS system which has been success-fully retrofitted to about 80 reactors world-wide. In a first step, AREVA and EPZ investi-gate to replace the existing Reactor Control and Limitation System (RCLS) by new digi-tal technology.

Cooperation in plant service extended

Besides the cooperation in the field of in-strumentation & control technology, AREVA supports EPZ also with service and mainte-nance work. A Long-Term Service Agree-ment (LTSA) has been signed contracting AREVA experts to perform outage and main-

Milestones

1969 The Provincial Zeeland Power Company (PZEM) orders a reactor from Siemens KWU (now AREVA GmbH).

1973 On October 25, 1973, following successful startup tests, Siemens KWU hands over the reactor to PZEM. The government issues a permanent operating license.

1979 to 1984 Safety facilities were upgraded including the construction of a reserve cooling water system.

1987 The Borssele reactor becomes part of the Electricity Producers Co-operative (SEP) in Arnhem.

1990 Ownership of the reactor is transferred to a public limited company, EPZ (Southern Netherlands Electricity Production Company).

1994 to 1997 An upgrade project, known as “MOD97”, is completed successfully at a cost of 450 million Guilders.

2006 The Borssele Covenant is signed in Goes that allows the Borssele reactor to continue operation under specific conditions until 2034 and a major overhaul of the Borssele reactor takes place. The temporary shutdown also allows a turbine upgrade by approximately 35 megawatts.

2012 Salto Peer Review conducted corresponding to IAEA long-term operation guidelines

Starting 2013

Step-by-step modernization of the current I&C system.

Signing of the LTSA

tenance services at KCB until 2019. In addi-tion to reactor and steam generator servic-es, the contract comprises chemical con-sulting and analyses, service for I&C and electrical systems as well as in-service in-spections.

Partnership also in fuel services

Apart from the close cooperation in plant technology, EPZ and AREVA also cooper-ate  in fuel supply. KCB’s fuel assemblies are made by AREVA, whose specialists are also involved in fuel assembly manage-ment.

Borssele Nuclear Power Plant

The Borssele Pressurized Water Reactor is the only operating nuclear power plant in the Netherlands. The plant, built by AREVA’s predecessor company Siemens KWU, was connected to the grid in 1973 and originally designed for an operation-al period of 40 years. In 2006, the Dutch authorities approved a continuing opera-tion under strict conditions: The nuclear power plant will supply power until 2034.

Today, Borssele has a net electrical out-put of 482 megawatt and supplies ap-proximately 80,000 households with car-bon-free power.

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