05000219/LER-1982-051, Forwards LER 82-051/03L-0.Detailed Event Analysis Encl

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Forwards LER 82-051/03L-0.Detailed Event Analysis Encl
ML20069P649
Person / Time
Site: Oyster Creek
Issue date: 11/23/1982
From: Fiedler P
GENERAL PUBLIC UTILITIES CORP.
To: Haynes R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20069P652 List:
References
NUDOCS 8212080240
Download: ML20069P649 (4)


LER-2082-051, Forwards LER 82-051/03L-0.Detailed Event Analysis Encl
Event date:
Report date:
2192082051R00 - NRC Website

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GPU Nuclear g gf P.O. Box 388 Forked River. New Jersey 08731 609-693-6000 Writer's Direct Dial Number:

November 23, 1982 Mr. Ronald C. Haynes, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

Dear Mr. Haynes:

Subj ect: Oyster Creek Nuclear Generating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/82-51/03L This letter forwards three copies of a Licensee Event Report (LER) to report Reportable Occurrence No. 50-219/82-51/03L in compliance with paragraph 6.9.2.b.4 of the Technical Specifications. We recognize that the time limitation specified in Technical Specification paragraph 6.9.2.b has been exceeded.

The delay in submittal of this LER is attributed to the failure to prepare a deviation report, which is the administrative mechanism which initiates management review for corrective action and the determination of reportability, at the time of discovery of this event. A deviation report (82-223) was subsequently prepared on October 18, 1982. It should be noted that although the deviation report was filed af ter the occurrence date, investigation and corrective action were initiated immediately following discovery.

Very truly yours,

g. A Y .

i fiyf & b' Peter'B. Fiedler Vice President and Director Oyster Creek cc: Direc t or (40 copies)

Of fice of Inspection and Enforcement U.S. Nuclear Regulatory Commission Wa shi ng ton, D.C. 20555 Direc t or (3)

Of fice of Management Information and Program Control U.S. Nuclear Regulatory Commission Washington, D.C. 20555 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, NJ 08731 8212080240 821123 PDR ADOCK 05000219 lear is a part of the Genere Pubhc Utihties System g,t.2, S PDR

OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/82-51/03L Report Date November 23, 1982 Occurrence Date September 30, 1982 Identification of Occurrence An abnormal degradation of the Waste Surge Tank located outside on the northwest side of the Old Radwaste Building caused an unmonitored release of radioactive liquid to the soil in the vicinity of the tank via tank, pump, and/or attached pipe leakage.

This event is considered to be a reportable occurrence as defined in the Technical Specifications, paragraph 6.9.2.b.4.

Conditions Prior to Occurrence Not applicable.

Description of Occurrence On the evening of September 21, 1982, a Radiological Controls Technician had performed a survey in the vicinity of the waste surge tank. When he completed his tour , he found that his shoes were contaminated. Ef forts were immediately initiated to remove the contaminated soil. During the decontamination effort, the pattern of the contaminated soil and the depth vs. the activity level indicated the cause of contamination was the waste surge tank.

An inspection of the waste surge tank on September 30, 1982, confirmed i degradation of the tank.

Many soil samples were taken in the area of the waste surge tank. The following is a summary of the highest activities obtained from each set of samples:

TABLE I ,

Co 60 Cs 134 Cs 137 Mn 54 Zn 65 10 CFR 30.70 Limit SE-4 9E-5 None IE-3 lE-3 9/21/82 and 9/22/82 3.6E-2 3.9E-3 2.7E-2 1.03E-3 1.07E-3 9/28/82 through 9/30/82 8E-5 4.6E-6 1.3E-4 4.8E-7 10/7/82 2E-4 2.4E-5 3.4E-4 2.8E-6 10/13/82 1.6E-4 1.4E-5 1.9E-4 1.5E-6 10/27/82 4.7E-5 1.8E-6 6.7E-5 None l All values in microcuries per gram

Licensee Event Report Page 2 Reportable Occurrence 50-219/82-51/03L 9/21/82 and 9/22/82 These samples were taken from the surface down to a depth of one foot and were analyzed in-house.

9/28/82 through 9/30/82 The environmental controls group took nine core borings just outside the fenced area surrounding the tank. Three of these were angled toward the tank.

4-5 samples were taken at different depths down to ten feet deep from each core hole. These samples were analyzed by Radiation Management Corporation (RMC) 4 under contract to GPU Nuclear.

10/7/82 The environmental group used a post hole digger to .

take samples from a depth of 3 feet. These samples were in the area of the samples taken on 9/21 and 9/22. Samples were analyzed by RMC.

10/13/82 Samples were taken in the same manner as those taken on 10/7/82 down to a depth of 6 to 7 feet below original grade. Samples were analyzed by RMC.

10/27/82 Samples were taken in the same manner as 10/7 and 10/13 down to a depth of 7 to 8 feet below original gra de. These were also analyzed by RMC.

The higher activity samples taken on 9/21 and 9/22 were f rom the vicinity of the waste surge tank drain nozzle and waste surge tank pump which is mounted on a diked pad. Therefore, there was only a small volume of dirt with the higher 1 ac tivi ty. Most of the samples taken were below the 10 CFR 30 limits for Co 60. The total activity contained in the excavated soil has been 4

conservatively calculated to be 0.66 curie.

The environmental controls group checked the test wells of f site as well as the j test well that was recently drilled on site near the af fected area. None of the test wells showed any activity. The well drilled on site showed the water table to be at least 29 feet below grade.

Apparent Cause of Occurrence The apparent cause of waste surge tank degradation was severe pitting of the bottom ten feet of sidewall and bottom of the tank. In addition, a cracked weld was found on the tank drain nozzle. Although it has not been determined whether any of the pits went completely through the bottom of the tank, the contamination is believed to have been caused by waste surge tank and pump leakage and/or leakage from the attached drain piping.

l

Licensee Event Report . Page 3 Reportable Occurrence No. 50-219/82-51/03L l

The weld crack in the drain nozzle is believed to be due to low cycle fatigue caused by buckling of the tank floor which in some areas is as high as three inches of f the foundation.

j The waste surge tank, which is made of aluminum, was designed for condensate

quality water between pH 5 and 7.5. In recent years, the tank has had very little service and only with condensate quality water. However, during past service for old radwaste, the tank was exposed to less pure water coming from such systems as the Floor Drain System, the Waste Collection System, and the Waste Neutralizing Tanks.

Analysis of Occurrence l Based on the depth of the water table, samples taken from the test wells and soil, the radioactive liquid that leaked to the soil was totally contained j within the radiologically controlled area of the plant and did not in any way af fect the ground water or the health and safety of the general public.

Corrective Action .

i Immediate corrective action was to remove the tank from service. The tank interior was hydrolazed to remove all sludge and was then pumped dry to prevent further leakage of contaminated liquid. Various portions of the ground were covered and samples were taken. When the results of the samples taken showed higher than 10 CFR 30.70 limits, excavation was initiated in order to ensure activity at ground level was lef t below 10 CFR 30.70 limits.

The waste surge tank has been condemned. An evaluation is being performed to determine whether the tank will be repaired, replaced, or removed entirely.

A study is being initiated to review all external piping, flanges, valves and tanks which contain contaminated fluids. The degree of protection provided against leakage to the soil will be evaluated, and appropriate corrective actions pursued, if required.

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