05000219/LER-1981-028, Forwards LER 81-028/03L-0.Detailed Event Analysis Encl

Forwards LER 81-028/03L-0.Detailed Event Analysis Encl

ML20010A431
Person / Time
Site:	Oyster Creek
Issue date:	08/03/1981
From:	Carroll J JERSEY CENTRAL POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20010A432	List: 05000219/LER-1981-028, Forwards LER 81-028/03L-0.Detailed Event Analysis Encl 05000219/LER-1981-028-03, /03L-0:on 810706,unmonitored Release of Rx Bldg Ventilation Air Occurred.Caused by Tear in Plastic Sheeting Used to Seal Section of Ductwork.Leak Isolated & Exhaust Fans Swapped
References
NUDOCS 8108110427
Download: ML20010A431 (3)

LER-1981-028, Forwards LER 81-028/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191981028R00 - NRC Website

text

______

y a

OYSTER CREEK NUCLEAR GENERATING STATION l

f._'.;+'f.a?f' lu,?.^C '.YJ",

(609)693-6000 P.O. BOP V ?

• FORKED RIVER

• NEW JERSEY

• 08731 J

w n

August, 1981 1[/g/

1 Mr. Boyce H. Grier, Director

(,

I

- ) )'

UL' Office of Inspection and Enforement j

United States Nuclear Regulatory Carmission

[(gg 10 1981 > 32 Region I g-

,, toss ;

631 Park Avenue c*55 0' King of Prussia, Pennsylvania 19406 9

/

4 N

Dear Mr. Grier:

/ w SUBJECI': Oyster Creek Nuclear Generating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/81-28/3L This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/81-28/3L in cmpliance with paragraph 6.9.2.b.4 of the Technical Specifications.

Very truly yours,

/ M ah d J. T. Carroll, Jr.

Director Station Operations JIC:dh Enclosures cc: Director (40 copies)

Office of Inspection and Enforement United States Nuclear Regulatory Carmission Washington, D.C.

20555 Director (3)

Office of Management Information and Program Control United States Nuclear Regulatory Catmission Washington, D. C. 20555

% Stl NRC Resident Inspcer (1)

Oyster Creek Nuclear Generating Station Forked River, N. J.

8108110427 810803 PDR ADOCK 05000219 S

PDR

- o OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Peport Reportable Occurrence No. 50-219/81-28/3L Report Date August 3, 1981 Occurrence Date July 6, 1981 Identification of Occurrence An urmonitored release of reactor building ventilation and turbine building air occurred through a tear in the seal of a section of ductuork for the new raawaste ventilation exhaust.

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

Conditions Prior to Occurrence h e plant was operating at steady state power.

Major Plant Parameters Power:

Reactor 1602 m t Generator 525 me 4

Flcw:

Recirculation 14.5 x 10 p Feedwater 5.94 x 106 lb/hr Description of Occurrence On July 6,1981 at approximately 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br /> a tear was discovered in a plastic seal used to tenporarily block a newly installed section of ventilation duct for the new radwaste ventilation exhaust. The duct had been tied into the discharge duct of reactor building exhaust fan EF-1-6.

W e other end of the duct was tmporarily sealed with plastic sheeting over a wooden frame until it could be tied into the existing new radwaste ventilation systs.

Assuming the tear was made inmediately after the last visual observation verifying that the seal was intact, the ccnservative estimate for a maximum release is 58,540 cubic feet of air. This figure is based on fan loadings and pressure readings in the ductwork. The maxinum release rate occurred when EF-1-6 was operating for a period of approximately 20 minutes on July 6.

This is estimated to be 650 cfm. It is possible for the release to have existed for an aMitional 92 hours0.00106 days <br />0.0256 hours <br />1.521164e-4 weeks <br />3.5006e-5 months <br /> when exhaust fan EF-1-7 was operating'. EF-1-6 fan may be used as a back-up for EF-1-7.

The estimated release rate with this fan operating is 8.5 cfm.

Reportable Occurrence Page 2 Report No. 50-219/81-28/3L Apparent Cause of Occurrence The cause of the release was a 6" x 6" triangular tear in the plastic used to seul the duct and a leaking sealing surface which permitted air to escape to the enviroment. The strength of the plastic was adequate to withstand any back-pressure developed by the exhaust fans. We tear was apparently made through physical abuse, but the specific means is unknown.

Analysis of Occurrence The most restrictive dispersion factor (X/Q) for a ground level release frm the new radwaste building is 2.5 x 10-5 sec/m. We maximtun flow rate during the 3

release was less than 700 cfm (for conservatism, 700 cfm is used for calculations).

5 These values yield a dilution factor at the fence line of 1.21 x 10. Applying this factor to the isotope with the highest concentration to MPC (maximum permissable concentration) ratio that was released (I-131) yields a concentration at the fence line of 1.53 x 10-14 pCi/cc for I-131. This concentration is approximately 0.00015% of the MPC for unrestrictive release to the env.trortnent.

All other isotopes released had valtws less than this.

The maximum total quantity of air released was 58,540 cubic feet during a maximtzn time period of 92 hours0.00106 days <br />0.0256 hours <br />1.521164e-4 weeks <br />3.5006e-5 months <br /> red 20 minutes. In this time period less than 60 pCi of activity were released. This value is less than the amount of activity which is normally released frm the new radwaste building ventilation exhaust systs during normal operation, which is within all limits given in the Technical-Specifications. Based on the above discussion, the safety significance of the event is considered minimal.

Corrective Action

The immliate action taken was to shut down exhaust fan F-1-6 and restart E 5.

Metal flanges were secured over the openinga in the ductwork, thereby isolating the leak. The conpletion of the ductwork tie-in with the existing new radwaste ventilation exhaust is expected in the near future. In addition, all special procedures for Installation ofitdifications by contractors will require a field review (walkdown) with operations supervision. The procedure for installation of this modification will be reviewed and revised if necessary, prior to final tie-in of the new duct.

Failure Data Not applicable.