Nuclear core cracking a long running problem

Well over a decade ago cracking of the reactor core graphite records for places like Heysham were, the Nuclear Installations Inspectorate (NII) told us, ‘closed documents’ did any politicians press the issue...Not that we are aware.

The issue of cracking of the graphite bricks which line the nuclear core of the UK's nuclear plants (see earlier post) is a deep seated one we had correspondence about this over a decade ago with Mike Weightman who was then the Chief Inspector of Nuclear Installations at the NII.

The NII responded to a wide range of queries in November 2006. We asked a series of general questions but specifically requested details on Wylfa (in Anglesey which is now closed) and Heysham in Lancashire. Here’s what they told us:

“Limited graphite brick cracking has been found at Heysham, but none at Wylfa. NII has reviewed the safety case for Heysham and is satisfied reactor operation should continue. Reports regarding the limited graphite brick cracking at Heysham have been produced but these are closed documents. You may be able to have sight of the report by requesting to HSE under the Freedom of Information Act. Further information regarding Freedom of Information is available at HSE Web page at: www.hse.gov.uk foi”

The HSE and Power Station operators are more open now so it shows it pays to press the issue but are we still getting edited highlights? I wonder!

We also asked about unscheduled reactor shutdowns. This is where a reactor trips out itself as opposed to a scheduled maintenance close down. It was an issue we had been pressing HSE/NII on for some years. The incidents are quite frequent indeed one occurred and is recorded recently in the Quarter 4 (2018) bulletin for Heysham.

NII told us in 2006

‘Unplanned reactor trips’ did not meet their criteria for reporting.

However they subsequent relented and provided comprehensive details of reactor trips going back several years across the nuclear industry. As indicated they now do record these occurrences.

For information quarterly reports for all UK nuclear installations can be found at this website of the Office of the Nuclear Regulator:

http://www.onr.org.uk/llc/index.htm

There is greater openness these days but only because campaign bodies like the League and colleagues in England, Scotland, Wales and Ireland have pressed for accountability.

Image: AGR graphite core - Heysham

Bernard Moffatt

Assistant General Secretary
Celtic League