PNO-II-88-015, on 880229,licensee Informed NRC That Unit,A 1 Mwt Pool Reactor Had Been Shut Down Due to Primary Coolant Leak Outside Containment.Region II Has Dispatched Both Health Physics & Operations Inspector to Review Event

PNO-II-88-015:on 880229,licensee Informed NRC That Unit,A 1 Mwt Pool Reactor Had Been Shut Down Due to Primary Coolant Leak Outside Containment.Region II Has Dispatched Both Health Physics & Operations Inspector to Review Event

ML20212C652
Person / Time
Site:	North Carolina State University
Issue date:	03/01/1988
From:	Fredrickson P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-88-015, PNO-II-88-15, NUDOCS 9710300072
Download: ML20212C652 (1)

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&&M Y( March 1, 1988 fv PRELIMINARYNOTIFICATIONOFEVENTORUNUSUALOCCURRENCEPNO-II-88h5 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or i public interest significance. The information is as initially received without verifi-cation or evaluation, and is basically all that is known by the Region 11 staff on _this date.

FACILITY: North Carolina State University Licensee Emergency Classification:

Pulstar Notification of Unusual Event Docket No. 50-297 Alert  !

Site Area Emergency  ;

General Emergency X Not Applicable

SUBJECT:

REACTOR COOLANT LEAK IN UNRESTRICTED AREA On 2/29/88, the licensee informed the NRC that the unit, a 1 MWt pool reactor, had been shut down due to a primary coolant leak outside containment. The last time the reactor had been operated was 2/26/88. The leak was isolated on 2/29. Coolant loss is believed to have been slowly increasing for several weeks. It became obvious as a leak when, over the last week the loss increased from 60 gpm to approximately 180 gallons per day (gpd), which is significantly higher than the normal pump-seal and evaporative losses. The February pool water sample contained 2.88 E-6 uCi ml (MPC IE-4) of Mn56; 7.79 E-7 uC1/ml (MPC 2E-4)

! of Na 24; and less than 3.1 x 10-5 uC1/ml of tritium (MPC 3 E-3). The licensee is taking additional _ samples of the pool water for analysis.

f The portions of piping that are outside the facility include several hundred feet of 10"

( stainless steel pipe and a Nitrogen 16 delay tank. Piping is buried between 5 and 15 feet underground. The hot leg (119') and cold leg (104') were pressure drop tested and the leak-has tentatively been located in the cold leg. Radiation levels and contamination levels on the; soil above _the pipe are not above background. Measurements of wet spots inside the reactor building air intake cubicle, located outside the containment where the pipes emerge from the soil, showed contamination levels below 1000 dpm/100cm2 Access to this cubicle is controlled by a locked grating. The licensee is reviewing the situation and has agreed to'not restart without NRC notification. Region 11 has dispatched both a health physics and operations inspector to review the event and evaluate corrective actions. The licensee

'is considering issuing a press release.

The' State of North Carolina was informed by the licensee.

The NRC received initial notification of this event by telephone from the licensee at 4:30 p.m. (EDT) on February 29, 1988.

This information is current as of 10:30 a.m. (EST) on March 1,1988, CONTACT: P..Fredrickson - 242-5649 1/

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", C/R Distribution:

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v 5X036 9710300072 880301 PDR I8sE PNO-II-88-015 PDR

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