Tag Archives: reactor

Iran breaches another nuclear deal cap, on heavy water stock: IAEA report

Iran breaches another nuclear deal cap, on heavy water stock: IAEA report
VIENNA (Reuters) – Iran has breached another limit of its nuclear deal with major powers by accumulating slightly more than 130 tonnes of heavy water, a substance used in a type of reactor it is developing, a U.N. nuclear watchdog report showed on Monday.

The limit is the latest in a series imposed by the deal that Iran has exceeded in protest at Washington’s withdrawal from the deal last year and its imposition of punishing economic sanctions against Tehran.

Heavy water is not as sensitive as uranium, which Iran is enriching in a quantity and to a level of purity beyond limits in the deal. However, the 2015 deal says Iran should not have more heavy water than it needs, specifying this is estimated to be 130 metric tonnes.

“On 16 November 2019, Iran informed the Agency that its stock of heavy water had exceeded 130 metric tonnes,” the International Atomic Energy Agency said in a report to member states obtained by Reuters.

“On 17 November 2019, the Agency verified that the Heavy Water Production Plant (HWPP) was in operation and that Iran’s stock of heavy water was 131.5 metric tonnes.”

Heavy water is, among other things, used as a moderator to slow down reactions in the core of nuclear reactors like one Iran has been developing at Arak.

Since that reactor could eventually have produced plutonium, which can also be used in atom bombs, the deal required Iran to remove its core and fill it with concrete. The reactor is now being redesigned with a view to reducing any weapons proliferation risk.

It is not the first time Iran has breached the heavy-water cap. Iran first went over that limit in 2016 https://www.reuters.com/article/us-iran-nuclear/iran-once-again-exceeds-a-nuclear-deal-limit-iaea-report-idUSKBN1342T1, soon after the deal went into force and well before the U.S. withdrawal in 2018. Major powers then agreed Iran could store its excess heavy water outside the country while it sought a buyer for it.

(Reporting by Francois Murphy; Editing by Catherine Evans)

Cracks in Scottish nuclear reactor core prompt safety checks

FILE PHOTO: The Hunterston nuclear power station in West Kilbride, Scotland May 15, 2013. REUTERS/Suzanne Plunkett/File Photo

By Nina Chestney

LONDON (Reuters) – A reactor at EDF Energy’s Hunterston B nuclear power plant in Scotland will remain offline for additional safety checks after cracks were found in its core, Britain’s Office for Nuclear Regulation (ONR) said.

Ageing reactors generate just over 20 percent of Britain’s power but almost half of this capacity, including Hunterston, is due to go offline by 2025, prompting the government to plan new plants.

ONR was informed in March about keyway root cracks found during planned inspections of graphite bricks in the core of Reactor 3 at Hunterston.

Graphite bricks ensure reactors can be cooled and thousands of them are used in reactor cores.

“Inspections confirmed the expected presence of new keyway root cracks in the reactor core and also identified these happening at a slightly higher rate than modeled,” EDF Energy said in a statement.

The reactor has been offline since March and was due to come back online this month, but EDF Energy has extended the outage until later this year.

“While Hunterston B Reactor 3 could return to operation from the current outage, it will remain offline while the company works with the regulator to ensure that the longer term safety case reflects the findings of the recent inspections and includes the results obtained from other analysis and modeling,” it said.

Hunterston B in North Ayrshire, Scotland, has been generating electricity since 1976. Last year, it produced enough electricity for 1.8 million homes.

CRACKS

In 2015, EDF Energy said routine inspections had revealed cracks in part of the graphite core at a Hunterston B nuclear reactor. It said three of 6,000 bricks had cracked, something that had been expected to begin happening at that point in the power station’s life.

Two of EDF Energy’s nuclear power plants in Britain – Heysham 1 and Hartlepool – were offline for months in 2014 for inspections after a crack was found on a boiler spine at Heysham 1.

In Belgium, the regulator ordered production to be stopped at two nuclear reactors in 2012 after finding indications of tiny cracks in core tanks.

The cracks turned out to be particles of hydrogen that were trapped inside the tanks when they were made by a Dutch company in the early 1980s.

EDF said it expects Hunterston B’s Reactor 3 to return to service “before the end of 2018”. EDF Energy’s outage website shows an expected return date of Oct. 4.

Its Reactor 3 and Reactor 4 are both Advanced Gas-cooled Reactors. The outage will reduce its 2018 output by 3 terawatt hours, the company said.

EDF Energy said the operation of its other UK reactors was not affected.

(Reporting by Nina Chestney; Editing by Jason Neely and Mark Potter)