APR: your source for nuclear news and analysis since April 16, 2010

Tuesday, April 2, 2013

Arkansas Nuclear One update - 4/2

As of this morning, there has been exceedingly little new information released about Sunday's industrial accident at ANO Generating Station.  The briefest timeline follows.

While workers were moving a roughly 500 ton piece of equipment from its installed location to the transport bay in the center of the ANO turbine building, the crane or lifting rig being used to move the equipment collapsed.  The piece of equipment, a turbine stator, fell down to the floor of the transport bay, resulting in one death and eight injuries.

The impact was heard by numerous residents in the community surrounding the plant; this was reported on several local sources (primarily TV stations.)

Damage resulted to both electrical equipment and to a fire main, with a number of results which affected plant operations.

-Unit 1, already shut down for maintenance, lost all offsite AC power but diesels immediately started automatically

-Unit 2 lost power to reactor coolant pumps; the reactor tripped (scrammed) and for immediate cooling, the atmospheric steam dumps were used.  This procedure and method of cooling for a reactor which has tripped from full load happens more frequently than one might think.  Local citizens also heard the roar of the steam being discharged to atmosphere.  (Again - this is normal, and no radiological release occurred.  Normally the steam coming from the steam generators is monitored at all times, and the plant would have been required to shut down if there were a primary to secondary leak.)

Later, water from the fire main caused some AC power at Unit 2 to fail, but when that occurred (about two hours after the crane failure) the emergency diesels automatically started.

Both reactors are shut down safely.  (One already had been before.)  NRC and OSHA are on site with Entergy officials, as reported in yesterday's press. 

There are inside reports of structural damage to the (very large) support structure for Unit 1's turbine generator.  (A nuclear plant's turbine generator can be over 225 feet long and weigh over 5000 tons completely assembled; the support structure is even larger and heavier.)  None of those has been either confirmed or denied by Entergy -- or for that matter even acknowledged.

More details are sure to emerge soon.  Some questions we'd expect to be answered:


-What is the condition of the survivors?  Will all recover fully? 
-What is extent of damage to Unit 1's turbine generator support? 
-Is the Unit 1 replacement stator on site?
-What is extent of damage to equipment related to Unit 2 .. and can Unit 2 expect an extended forced outage as a result of this incident?
-Will the industry enforce a "heavy lift safety stand-down" to review lift procedure, equipment integrity, and equipment testing?

Follow here, and on Twitter (  @atomicnews  )  for further updates.  Background news links below.

Entergy - Initial Press Release

Entergy - Later Press Release

NRC Event Report - issued Monday and amended

NRC Blog post with clarification of details

Platts - OSHA to ANO industrial accident scene

1:10 PM Eastern 4/2/2013
ATOMIC POWER REVIEW



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2:00 PM    The Pope County Coroner has officially identified the worker killed at ANO over the weekend (even though the identity was already fairly widely known.)  Wade Walters, of Russellville Arkansas was killed at the scene of the industrial accident at ANO on Sunday.  Click here.

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PHOTOS of the industrial accident have now begun to circulate fairly widely around the internet.  They are appearing on approximately five known websites at this time.  Here is a link to one.

ARKANSAS NUCLEAR ONE INDUSTRIAL ACCIDENT PHOTOS

The photo page above contains a link to where the PROS apparently found the photos; that original page is seen at this link. 

2 comments:

  1. I know it's a quibble, but when even Professional Reactor Operator Society is incorrectly calling this a "Arkansas Nuclear Accident", we got a lot of public relations/education accuracy issues at play here to straighten out that can only be fodder in the antis hands.

    James Greenidge
    Queens NY

    ReplyDelete
  2. Heavy lifting fixtures are normally designed with a large safety factor (x2 or x3). Some other questions I'd pose:
    - Was there a problem with the design here?
    - Was the fixture in good condition?
    - Was it used correctly?

    ReplyDelete