PNO-III-97-061, on 970725,facility Lost Steam Supply from Onsite Steam Production Plant.Normal Feedwater Lost to Two Boilers,In Svc Apparently Due to Plugged Aerators.Feedwater Restored Through Bypass Line

PNO-III-97-061:on 970725,facility Lost Steam Supply from Onsite Steam Production Plant.Normal Feedwater Lost to Two Boilers,In Svc Apparently Due to Plugged Aerators.Feedwater Restored Through Bypass Line

ML20149J559
Person / Time
Site:	Portsmouth Gaseous Diffusion Plant
Issue date:	07/28/1997
From:	Hiland P, Reidinger T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-97-061, PNO-III-97-61, NUDOCS 9707280271
Download: ML20149J559 (2)

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I July 28, 1997

. PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PN0-III-97-061 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received 1without verification or evaluation, and is basically all that is known by Region III staff (Lisle, Illinois) on this date. ,

Facility Licensee Emergency Classification U.S. ENRICHMENT CORPORATION Notification of Unusual Event Portsmouth Gaseous Diffusion Plant Alert '

- Piketon.0hio Site Area Emergency Dockets: 07007002 General Emergency X:Not Applicable

Subject:

' LOSS OF PROCESS STEAM SUPPLY

, - On July, 25, 1997, at approximately 6:30 AM. the facility lost. the steam supply from its onsite steam production plant. Normal feedwater was lost to the two boilers (#2 and #3) that were in service apparently due to  ;

plugged aerators.

. Feedwater was restored through a by) ass line. When cooler water from the bypass system reached the heated tu)es in the boilers, some of the tubes

. fractured and both boilers were taken out of service. .

The #1 boiler had been out of' service for maintenance, and the facility promptly began to return it to service.

l' Steam is used for nuh.erous activities at the plant including maintenance of sufficient tem)eratures in the process equipment and transfer lines to r

keep the uranium 1exafluoride in gaseous form. (Uranium hexafluoride will solidify-at normal ambient temperatures.)

l The plant monitored the enrichment cascade conditions and took actions.,

as necessary, to prevent process gas solidification. Equipment and piping which-is vulnerable to solidification has backup electrical heating c'evices to prevent temperature reduction to the solidification point.

There was no immediate safety concern.

The facility convened its Operational Assessment Team to review the recovery actinns for steam restoration.

- PNO-III-97-061 l l

l' Boiler I of the;#1 was full plant's returned to service requirement. but capacityauxiliary Non-essential is only 60 steam to 70use percent was curtailed. and assessment team developed a plan to install additional portable steam capacity. An electric generating unit and an electric O

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powered steam supply unit is being installed and should be operational on July 30.

Subsequent inspection of the two damaged boilers showed limited tube damage in the #2 boiler. It is being repaired and expected to be returned to service on July 28. There was extensive tube damage in the #3 boiler.

The duration of repairs is not known.

The two resident inspectors and an additional inspector from Region III (Chicago) were onsite monitoring the plant's activities. The Office of Nuclear Material Safety and Safeguards and Region III were also following the situation.

Region III and the Headquarters staff are planning a special inspection at Portsmouth beginning' July 29. The special inspection will focus on the root causes relating to the loss of steam generating capacity.

Preliminary findings will determine whether additional actions are warranted.

Region Ill was notified of the boiler damage at 6:30 a.m. on July 25, 1997 by Portsmouth Resident Inspection staff. This information is current as of 10 a.m. on July 28, 1997.

Contact:

TIM REIDINGER PAT HILAND

, (630)829-9816 (630)S29-9603 l

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