ML20210G936

Informs That Attachment Has Been Reviewed & Approved in DNMS Re Palisades Pn

ML20210G936
Person / Time
Site:	Palisades
Issue date:	06/10/1999
From:	Strasma J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Jorgensen B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20210G839	List: ML20210G835 ML20210G879 ML20210G887 ML20210G909 ML20210G936 ML20210G941 ML20210G961 ML20210G971
References
FOIA-99-264 NUDOCS 9908030234
Download: ML20210G936 (4)

Text

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j [ Bruce Jorgensen - PALISADES P.N. Pags 1 l From: Bruce Jorgensen N To: Jan Strasma -~

Date: Thu, Jun 10,199912:49 PM

Subject:

PALISADES P.N.

See attached; it has been reviewed and approved in DNMS and read to the licensee so it is ready to issue.

Changes were MAJOR. The licensee leamed just before noon that this happened twice (!!!!) with two different welders, at 5:00 and 7:30! Jim Dyer needs to have a close look at it.

I also did a minor edit here and there, and I added the fact that a cask team inspector was onsite till after the shield lid was welded on.

Regards, 9900030234 990729 I PDR FOIA 'q GUNTER99-264 PDR l~ l 9908o3o2Sy )

j [ Bruce Jorgensen - palh2fn.wpd Piga 1]

DRAFT - DRAFT - DRAFT - DRAFT - DRAFT - DRAFT - DRAFT - DRAFT s

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

After this information is reviewed by the responsible. technical division and any changes made, it should be forwarded by e-mail to IEO (the data entry staff) for entry into the IEvents system and issuance by e-mail.

IS THIS AN UPDATE?

IF SO, WHAT WAS THE ORIGINAL NUMBER J

> j l

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

(FOR OTHER FACILITY, NAME AND CITY / STATE)

> Palisades i

~ LICENSE NO: (FOR ALL LICENSEES EXCEPT NUCLEAR PLANTS) l EVENT CLASSIFICATION: (GENERAL EMERGENCY, SITE AREA EMERGENCY, ALERT, j UNUSUAL EVENT OR NONE) J

>Not applicable CONTACTS: NAME AND TELEPHONE NUMBER (TWO REQUIRED) 1>Ross Landsman 630/829-9609 2* Bruce Jorgensen 630/829-9615

SUBJECT:

> MINOR HYDROGEN BURN DURING CASK WELDING ACTIVITIES TEXT:

>At about 5:00 p.m., and again at about 7:30 p.m. EDT on June 9,1999, minor hydrogen burns occurred during welding of the structural lid on a spent fuel storage cask following its loading earlier

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[ Bruce Jorgenseri'"~palii2fn.wpd Pag; 2]

in the week. These brief hydrogen bums occurred at the discharge end of tubing being used to draw gases from the interior of the cask.

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 burn during cask 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 shielding purposes, was removed from the spent fuel storage pool. The inner shield lid had been welded in place, and workers had begun welding the structurallid.

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 the cask and the other to a filtering device. The tubing became separated from the j filter, and sparks from the grinding ignited the hydrogen at the discharge end of the tubing. In each instance the welder observed a small flame at the end of the tubing, pinched the tubing, and extinguished the flame. l I

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

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

The use of a ventilating system on the cask has been standard practice at Palisades. It is also one  !

of the corrective actions following the Point Beach hydrogen burn event, to prevent a combustible 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 I long as the boric acid in the water is present in the cask, hydrogen will L e produced. When the 1 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 at the discharge of the tubing, and no air was being added to the cask itself that would support ignition of any hydrogen j inside the cask. The flames were easily extinguished. No injuries or equipment damage resulted. i The presence of hydrogen was an expected phenomenon, and the ventilation systerr. was functioning to prevent the accumulation of a potentially combustible concentration inside the cask.

An NRC resident inspector is following the licensee's response to the incident. 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 returns to the site to continue the l inspection next week.

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

Region 111 (Chicago) learned of these two occurrences separately, first being informed of one event at about 8:00 a.m. CDT on June 10,1999, and later (at about 12:30 p.m.) learning there had been two occurrences. This information is current as of 12:45 p.m. on June 10,1999.

[ Bruce Jorgensen - palh2fn.wpd, a

Paga 3]

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