PNO-III-86-108, on 860926,radiation Monitor for Condenser Air Ejector Alarmed in Control Room.Caused by Two Tanks of Argon Gas Inadvertently Connected W/Hydrogen Tanks Used to Supply Cover Gas for Vol Control Tank.Tanks Disconnected

PNO-III-86-108:on 860926,radiation Monitor for Condenser Air Ejector Alarmed in Control Room.Caused by Two Tanks of Argon Gas Inadvertently Connected W/Hydrogen Tanks Used to Supply Cover Gas for Vol Control Tank.Tanks Disconnected

ML20210R631
Person / Time
Site:	Kewaunee
Issue date:	09/29/1986
From:	Guldemond W, Jackiw I, Schumacher M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-86-108, NUDOCS 8610070383
Download: ML20210R631 (2)

- - - -

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-86-108 Date Septembsr 29, 1986 DnB

% f*

This preliminary notification constitutes EARLY notice of events of POSSIBLE safety

or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region III staff on this date.

l Facility: Wiscensin Public Service Corp. Licensee Emergency Classification:

Kewaunee X Notification of an Unusual Event

Kewaunee, WI 54216 Alert Site Area Emergency l

Docket No. 50-305 General Emergency Not Applicable

Subject:

GASE0US RELEASE At 3:38 p.m. (CDT) on September 26, 1986, the radiation monitor for the condenser air ejector alarmed in the control room, and subsequently an alarm was received on the reactor coolant letdown system at 4:34 p.m. (CDT), indicating elevated radioactivity levels in the reactor primary coolant system. A primary coolant sample indicated the presence of argon-41, which is not nonnally present in the reactor cooling system.

Further investigation -- including analysis of a reactor coolant sample -- determined that two tanks of argon gas were mistakenly connected with four hydrogen tanks used to supply a cover gas for the volume control tank. (The hydrogen is used to prevent the buildup of free oxygen in the primary cooling system. Nonradioactive Argon-40 entered the primary coolant system and was activated as it passed through the reactor, becoming Argon-41.) The tanks ware disconnected, and the cover gas from the volume control tank was transferred about 5;40 p.m. (CDT) to the waste gas treatment system. During the transfer, minor leakage in the piping system resulted in a release to the auxiliary building. The radiation monitor on the auxiliary building vent stack detected the radioactivity and alaniied. Although the actual

. gas transfer had been completed, the residual radioactivity being released reached the threshold requiring the declaration of an Unusual Event under the plant's emergency. plan at

-6:10 p.m. (CDT). The Unusual Event was terminated at 3:33 a.m. (CDT), September 27,-1986, when the release levels returned to normal.

The licensee reported that approximately 3 curies of argon-41 were released and that the .

release rate was approximately 10% of the Technical Specification release limit. '

(Argon-41 has a half-life of 1.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />).

The Resident Inspector from the nearby Point Beach site was dispatched to Kewaunee at approximately 8 p.m. (CDT) to monitor the licensee's activities. A radiation specialist from R:gion III (Chicago) will perform a followup inspection this week to review the circumstances of the release.

1 DISTRIBUTION:

H. St. % 3.~l'8 M ED03.7/ NRR3.'.2/ E/W IN Willstel Mail: ADM:DMB Chairman Zech PA- IE NMSS DOT:Trans only Comm. Roberts ELD OIA RES Comm. Asselstine AE0D Conn. Bernthal Conn. Carr SP 103 Regional Offices 84.$21 M'WD ACRS A.s - 3:SD- At - 3:37 SECY CA-INP0 3'7 )

RIII Resident Office NSAC b h,

PDR- Licensee: 2:40 (Corp. Office - Reactor Lic. Only) 0 I i

86100g f W M kjo ber 1985 ,4f M-III-86-108PDR _ - - - - - - -

PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-86-108 Date September 29, 1986 s e" d

According to the licensee, the argon tanks were among a shipment of 12 tanks received from a supplier and specified as containing hydrogen. The argon tanks were identical in appearance and fittings to the rest of the tanks, although a small label correctly identified the cent nts as argon.

Tha licensee is investigating the source of the leakage from the waste gas treatment system and reviewing the procedures for hydrogen use to preclude a recurrence of this event.

There was local news media interest in the event.

The State of Wisconsin was informed of the Unusual Event classification.

Region III (Chicago) was notified of this event 6:30 p.m. (CDT), September 26, 1986, by the Headquarters Duty Officer. This information is current as of 9 a.m. (CDT), September 29, 1986.

CONTACT: I N. Jag tw 1"a 0 M. Schumacher

& 5--

W. G. Guldemond ge^

nS 3884697 FTS 388-5514 FTS 388-5574 I

-- _ _ _ , , , .