PNO-III-88-104, on 881221,licensee Detected Increased Airborne Radioactivity in Turbine & Offgas Bldgs.Airborne Activity Escaped from Offgas Treatment Sys When Water Seals in Sys Drain Lines Were Lost

PNO-III-88-104:on 881221,licensee Detected Increased Airborne Radioactivity in Turbine & Offgas Bldgs.Airborne Activity Escaped from Offgas Treatment Sys When Water Seals in Sys Drain Lines Were Lost

ML20212C573
Person / Time
Site:	Perry
Issue date:	12/22/1988
From:	Cooper R, Knop R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-88-104, NUDOCS 9710300035
Download: ML20212C573 (2)

PRELIMIllARY HOTIT,,,

v CATION OF EVENT OR UNUSUAL OCCURRENCE -PN0 II-88-104 Date Dec:mber 22, 1988 T'Nreliminary

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notification constitutes EARLY notice of events of POSSIBLE safety 311c interest significance. The information is as initially received without Lication or evaluation, and s basically all that is known by the Region III staff on this date.

Facility: Cleveland Electric Illuminating Licentee Emergency Classification:

Company Perry 1 Notification of an Unusual Event Alert Perry, OH 44081 iSite Area Emergency  ;

Docket No. 50-440

_,__ General Emergency Not Applicable hhg ) F *.

Subject:

LOSS OF WATER SEALS IN OFFGAS SYSTEM CAUSES MINOR RELEASE At about 10 p.m. on December 21, 1988, the licensee detected increased airborne radioactivity in the Turbine and Offgas Buildings. The airborne radioactivity escaped from the offgas treatment system when the water seals in system drain lines were lost.

The licensee declared an Unusual Event under its emergency plan at 10:07 p.m. The airborne radioactivity levels approached, but did not reach the level requiring the Unusual Event classification.

The licensee determined that a valve failed to open during a routine shift from one offgas system dryer to another. The dryer shift is an automatic operation, but the inlet valve to the second dryer failed to open. The resulting pressure increase in the offgas system forced o% the water loop seals in drain lines which remove moisture from the system. The loss of f

pals enabled gases to escape from the offgas system into the Offgas and Turbine buildings.

The dioactive gases were removed from the buildings through the normal ventilation systems, which are equipped with radiation monitors. The maximum release rate, which occurred about 30 minutes after the release started, was less than 10 percent of the Technical Specification limit for releases from the plant. The release rate decreased to normal levels 0:,cember after about 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The Unusual Event was terminated at 4:42 a.m. on 22, 1988.

S;veral plant workers received minor skin and clothing contamination as a result of the I

releases in the buildings. The radioactive materials were primarily cesium-138 and krypton-88, both of which are very short-lived. Whole body counts did not show any significant internal radioactive deposition for the workers.

Chm, Cmrs, C/R Oistribution:

9710300035 881222 Uk GPA, GC, CA, PDR, Historian, SECY, Records.

I 88-104 PDR .,,

m DISTRIBUTION: FR R WFN 1 MNBB IWFN E/W c'

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Chairman Zech XEDU DIX Comm. Roberts ARM 01 D _i4MST- d i y[M SL'ITP Comm. Carr C n . Rogers 1WFN PA Resident Inspector Offices 3 Mail To:

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OGC Resident Inspector CD DOT Trans. Only)

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OGC-H FAX T0: Nicholson Lane Regions CA INPO RES Region I GPA NSAC Region II ACRS Licensee Region IV PDR HQS. Operations Officer Region V RaRign III __

PRELIMINARY NOTI"! CATION OF EVENT.OR UNUSUAL OCCURRENCE--PNO-III-88-104 -Date December 22, 1988

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Power was reduced from 100 percent to 70 percent-to decree s the offgas flow and as a result a

' of decreased condenser vacuum _. There was no increase in ..sdrogen concentration in the

,offgas system and no_-temperature-increases in the charcoal adsorbers., The licensee is investigating the cause-of the valve failure which initiated the incident. The resident inspectors are monitoring the licensee's activities.

, - The State of Ohio will be notified.

l :-The licensee notified the> Headquarters Operations-Center of this event at 10:21 p.m. (EST) on December 21, 1988. This informatior:- is current as of 10 a.m. on December 22, 1988 L 7=

C0kTACT: R. Cooper- R. Knop FTS 388-5578: FTS 388-5547 j ;-

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