ML20210G909

Requests That Cio Make Copy of Pn to Be Sent to M Sinclair in Midland,Mi

ML20210G909
Person / Time
Site:	Palisades
Issue date:	06/10/1999
From:	Pirok D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Jorgensen B NRC
Shared Package
ML20210G839	List: ML20210G835 ML20210G879 ML20210G887 ML20210G909 ML20210G936 ML20210G941 ML20210G961 ML20210G971
References
FOIA-99-264 NUDOCS 9908030230
Download: ML20210G909 (3)

Text

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Steve O'Connor PAOSADES P.N. Pags

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From: Bruce Jorgensen -

To: Donna Pirok [)C.!O Date: Thu, Jun 10,1999 2:56 PM

Subject:

PALISADES P.N.

Please issue the attached P.N. Also please 'ask ClO to make sure a copy goes to Dr. Mary Sinclair in Midland, MI.

Thanks, CC: Ross Landsman, Timothy Kobetz 1

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OUNTER99-264 PDR

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I[ Steve O'Connor-palh2pn.wpd Piga 1

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DRAFT - DRAFT - DRAFT - DRAFT - DRAFT - DRAFT - DRAFT - DRAFT

! INFORMATION FORM FOR PREPARING A PRELIMINARY NOTIFICATION (Note: the PN software will automatically provide the date and number)

Afte'r this information is reviewed by the responsible technical division and any changes made, it should be forwardsd by e-mail to IEO (the data entry staff) for entry into the IEvents system and issuance by e-mail, l l l iS THIS AN UPDATE?

l IF SO. WHAT WAS THE ORIGINAL NUMBER l

1' l LICENSEE: (FOR NUCLEAR PLANT, NAME AND UNIT NUMBER)

(FOR OTHER FACILITY, NAME AND CITY / STATE) l.

> Palisades l LICENSE NO:(FOR ALL LICENSEES EXCEPT NUCLEAR PLANTS)  ;

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EVENT CLASSIFICATION: (GENERAL EMERGENCY, SITE AREA EMERGENCY, ALERT, UNUSUAL EVENT OR NONE)

>Not applicable

, CONTACTS: NAME AND TELEPHONE NUMBER (TWO REQUIRED) 1>Ross Landsman 630/829-9609 2> Bruce Jorgensen 630/829-9615

SUBJECT:

> MINOR HYDROGEN BURNS DURING CASK WELDING ACTIVITIES I

TEXT:

>At about 5:00 p.m., and again at about 7:30 p.m. EDT on June 9,1999, minor hydrogen bums occurred during welding of the structurallid on a spent fuel storage cask following its loading earlier in the week. These brief hydrogen burns occurred outside the cask at the discharge end of tubing being used to draw gases from the interior of the cask.

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• The cask was the fourteenth to be loaded at Palisades and the first since cask loading activities resumed. Storage cask loading activities had been halted to address issues identified following a hydrogen bum inside the cask during loading in May 1996 at the Point Beach plant and to address subsequent welding issues involving the Sierra Nuclear VSC-24 cask.

Loading of 24 fuel assemblies into the cask was completed on June 7 and the cask, still containing water for radiation shielding purposes, was removed from the spent fuel storage pool. The inner shleid lid had been welded in place, and workers had begun welding the structural lid.

The cask was still filled with water, and the small air space at the top was being ventilated through a small plastic tube to remove any hydrogen being produced in the cask. One end of the tube was connected to tha cask and the other to a filtering device. The tubing became separated from the filter, and sparks from the grinding ignited the hydrogen at the discharge end of the tubing. In each instance the welder observed 3 small flame at the end of the tubing, pinched the tubing, and extinguished the flame.

Work was stopped following the second incident, and the licensee's spent fuel storage cask group was notified. The discharge end of the ventilating tubing was reconnected to the filter unit and work activitics were resumed. Plant management was not informed until the moming of June 10,1999.

At that time, a second work halt was imposed by plant management pending further review.

The use of a ventilating system on the cask has been star.dard practice at Palisades. It is also one of the corrective actions following the Point Beach hydrogen bum event, to prevent a combust;ble accumulation of hydrogen inside the cask. The hydrogen is produced through a chemical reaction between boric acid in the water inside the cask and the zinc-based coating on the cask interior. As long as the boric acid in the water is present in the cask, hydrogen will be produced. When the welding is completed, the water will be removed and the cask will be filled with helium.

This hydrogen buming was of minor safety significance. The buming was outside the cask at the discharge of the tubing, and no air was being added to the cask itself that would support ignition of any hydrogen inside the cask. The flames were easily extinguished. No injuries or equipment damage resulted. The presence of hydrogen was an expected phenomenon, and the ventilation system was functioning to prevent the accumulation of a potentially combustible concentration inside the cask.

The NRC resident inspectors will follow the licensee's response to the incident and observe when the licensee resumes work. Also, a special NRC inspection on cask loading activities is ongoing, and a cask team inspector was onsite until after the shield lid weld was completed, although none of the cask team were onsite at the time of the incidents. These incidents will be reviewed when a team member retums to the site to continue the inspection next week.

The State of Michigan was informed. The information in this preliminary notification has been reviewed with licensee management.

Region 111 (Chicago) leamed of these this event at about 8:00 a.m. CDT on June 10,1999. This ,

information is current as of 12:45 p.m. on June 10,1999.

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