The exercise was carried out to test emergency procedures in the event of an accident involving radioactive materials.
Electronics giant Hitachi has announced it will buy nuclear power project Horizon, which includes a plan to build a new plant on Anglesey.
The new Welsh Secretary David Jones will pledge his support for a new nuclear power station on a visit to Wylfa on Anglesey.
Hundreds of business people have packed a conference in North Wales today to see just how a new nuclear power station could boost Anglesey's economy - and the finances and job prospects of the suppliers across the region.
Building the new Wylfa B reactor may be one of Wales' most controversial developments with some fierce opposition.
Today, the nuclear firm Horizon saw how many suppliers and industries want to be a part of that project.
Rob Shelley reports.
An existing nuclear reactor on Anglesey could continue producing power until December 2015, according to its operator.
Wylfa was expected to shut down in 2014.
On its website today, operator Magnox said the plans are subject to Periodic Safety Review (PSR) approval.
Reactor 2 at the site was shut down last year.
The company behind plans to build a new power station at Wylfa on Anglesey will share its vision for the site with local businesses today.
Horizon Nuclear Power is holding two events, one in Llandudno and one in Gloucester, to give local businesses a chance to see what opportunities are available.
There will be presentations from Horizon's chief operating officer and the chief executive of Hitachi, as well as a key note speech from Economy, Science and Transport minister Edwina Hart AM.
The events are expected to attract around 200 business delegates, as well as a range of industry bodies including the Energy Island Programme, the National Advanced Manufacturing and Research Centre Nuclear, and the Nuclear Industry Association.
Japanese electronic giant Hitachi confirms it has completed its purchase of Horizon Nuclear Power, which operates Anglesey's Wylfa Power Station.
As part of the deal, the companies will make "a multi-billion pound investment" in training engineers and staff for a new nuclear power station on the island.
Horizon says 6,000 construction jobs will be created, with 1,000 people employed when the new plant is completed.
– Alan Raymant, Horizon Nuclear Power
We’re delighted that the deal has completed. It secures the future of Horizon and represents a real economic opportunity for North Wales. Our project
will be a multibillion pound investment, creating around 6,000 construction jobs at peak, and 1000 operational jobs when completed.
In the meantime, I’m delighted to confirm a third year of funding for the cohort of apprentices going through the Coleg Menai scheme.
Horizon was created in 2009, as a joint venture between E.ON UK and RWE npower.
Joanna Simpson reports.
Plaid Cymru has issued a carefully worded statement reflecting the conflict between the party's opposition to nuclear power and the support for a new Wylfa power station from most of the party's members on Anglesey including the AM for Ynys Mon, the former Plaid leader, Ieuan Wyn Jones.
– Plaid Cymru Spokesperson
The news regarding Hitachi and Wylfa has been welcomed by local Party of Wales representatives and the party will, at a local and national level, continue to press for job training and creation schemes that benefit the local economy and local people. However, the Party of Wales favours a non nuclear energy plan for Wales and we remain opposed to new nuclear plants. Our long term vision is for Wales’s needs to be met through energy generated from the abundant renewable resources that are naturally available to us. We want to see the decision making powers over these issues devolved to Wales.
Plaid Cymru's leader, Leanne Wood, recently stated that the party has always opposed new nuclear power stations on new sites but gives Plaid's representatives on Anglesey the right to make up their own minds on building new stations on existing sites, balancing environmental concerns with jobs.
– Shadow Welsh Secretary Owen Smith MP
Leanne Wood’s silence on this today says it all. We know that as a party Plaid are anti-nuclear, and we know that their leader is anti-nuclear. Today’s announcement securing employment for 6,000 people and providing job security in the longer term is great news for Anglesey and north Wales. Leanne Wood has turned her back on hardworking families on Anglesey. It’s clear that her ‘economic vision’ for Wales does not extend as far as Anglesey.
The Labour MP for Ynys Mon, Albert Owen, has also supported a new nuclear power station but does not have the backing of all his colleagues. The Newport West MP Paul Flynn asked earlier this year if stopping a new reactor at Wylfa was an argument in favour of an independent Wales.
The #Wylfa deal will mean up to 6,000 construction and 1,000 long-term jobs, as well as making a huge contribution to UK energy security
@davidjonesmp delighted with Wylfa news glad we finally got there
Friends of the Earth Cymru have spoken out against the announcement that Japanese company, Hitachi, will be building a nuclear power plant on Anglesey.
The environmental charity has raised concerns about the competency of the company to build a power station after it was responsible for designing the plant involved in the Fukushima disaster.
– Gareth Clubb, Director of Friends of the Earth Cymru
This is turning back the clock for Wales. Nuclear power is an expensive technology from the past that generates highly toxic nuclear waste that will be sitting around in Anglesey for the next 150 years.
The only viable future is one that's powered by renewables. Investment in the nuclear red herring diverts scarce resources from the renewable revolution that is already providing tens of thousands of jobs right across Wales.
First Minister, Carwyn Jones AM, has described the decision by Japanese electronics company, Hitachi, to buy the nuclear power project Horizon, as "very good news" for Wales.
According to Hitachi, between five and six thousand jobs could be created during construction and a thousand permanent posts when it is up and running.
The First Minister says the move will help to "secure our energy supply in the future."
– Carwyn Jones AM, Wales' First Minister
This is very good news for Wales and the UK. The potential benefits of a new nuclear development on Anglesey would be substantial - not just in creating thousands of highly skilled jobs and boosting the supply chain - but in helping to secure our energy supply in the future.