05000219/LER-1981-071, Forwards LER 81-071/01T-0.Detailed Event Analysis Encl

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Forwards LER 81-071/01T-0.Detailed Event Analysis Encl
ML20042A291
Person / Time
Site: Oyster Creek
Issue date: 03/05/1982
From: Fiedler P
GENERAL PUBLIC UTILITIES CORP.
To: Haynes R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20042A292 List:
References
NUDOCS 8203230297
Download: ML20042A291 (4)
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LER-1981-071, Forwards LER 81-071/01T-0.Detailed Event Analysis Encl
Event date:
Report date:
2191981071R00 - NRC Website
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GPU Nuclear i.

Qg g7 P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number March 5, 1982 Mr. Ronald C. Hayne s, Adminis tra tor g

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gN Region I U.S. Nuclear Regulatory Commission 8

631 Park Avenue 4-MD King of Prussia, PA 19406 E bO2h =l

Dear Mr. Haynes:

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9 38 Subject: Oyster Creek Nuclear Generating Station is g

Docket No. 50-219 4

Licensee Event Report Q

O Reportable Occurrence No. 50-219/81-71/011 This letter forwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-219/81-71/01T in compliance with paragraph 6.9.2.a.(2) of the Technical Specifications.

During the extensive investigation performed in order to prepare this Reportable Occurrence, it was determined that the violations should have been reported under Section 6.9.2.a. (2) of the lechnical Specifications.

All of the information necessary to make this determination was not readily available when the reporting requirements were set forth on the date the violations were discovered.

If this information had been available, the normal procedure for an immediately reportable violation would have been followed.

Very truly yours, hn> b Peter B. Fiedler Vice President & Director Oyster Creek PBF:Ise Enclosures ec: Director (40 copies)

Of fice of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.

20555 Director (3)

Of fice of Management Information and Program Control U.S. Nuclear Regulatory Commission Washington, D.C.

20555 NRC Resident Inspector (1)

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c OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/81-71/01T Epport.Date March 5, 1982 Opcurrepce.Date December 31, 1981 Id.en,ti. fica. tion of. 0ccurrence It was determined that the Radwaste liquid effluent radiation monitor was not being surveilled in accordance with Section 4.6.A of the Technical Specifications. The subsequent extensive investigation also revealed that the limiting condition for operation given in Section 3.6.B.2 of the Technical Specifications was violated.

Con.d.itions. Prior. to. 0_cc.urrenc.e The plant was in various operating modes during the time period of February 1,1981 to December 31, 1981.

L p.espription_ o.f.0ccurrenc.e During the calibration of the Radwaste liquid effluent radiation monitor, one of the wires on the detector was found disconnected and the monitor was reading low by a factor of 10 throughout the operating range of the instrument. The monitor was taken out of service in order to perform inspections and electrical and chemical tests. A preliminary investigation revealed that the required surveillances had not been performed for most of the time period between February ~1981 and December 1981. The Technical Specifications require a daily check, monthly test and quarterly calibration. As of August 7,1981, the daily Radwaste Operations Log has included the channel check once per shift. The monthly operability test has never been performed, and the calibration was only performed upon completion of the installation.

(No procedures were' developed at the time of the installation.)

Apparen.t Cause of 0.c.curre.nc.e The cause of the occurrence was attributed to the lack of procedural and administrative controls at the time of the completion of the modification in January 1981.

Reportable Occurrence Page 2 Report No. 50-219/81-71/01T Analysis of Occurrence The new liquid effluent monitor was installed in early 1981 as part of a modification to an existing system.

Each time an overboard release is maJe, an isotopic analysis is performed and a maximum release rate is i

calculated prior to discharge.

During releases with the monitor operable, the valve alignment for the tank to be released is checked to be correct by an operator.

During releases with the monitor inoperable, the valve alignment is verified independently by two operators and an additional sample is taken while the release is in progress (in accordance with the Technical Specifications).

During the course of 1981, several releases were made with the liquid effluent monitor declared operable, when, in fact, it was operating in a degraded condition.

Fron August to December, the daily checks listed background icvels in the monitor of approximately 500-700 CPM, which were apparently one-tenth of the proper value due to the disconnected wire.

When the monitor was bench-tested and reinstalled, background levels were reading in the 5000-6000 CPM range.

The bench-testing also revealed that the one-tenth error was consistent throughout the operating range of the instrument.

In an attempt to determine an approximate date on which the monitor operability became degraded, the recorder strip-charts for the period of February to December were examined. The charts showed that from February 1 to April 12, the monitor was operable.

However, on April 12, a downscale indication was - received. The ratemeter was returned to service on April 13, but the recorder output was downscale from April 13 until the end of the year.

This indicates that the monitor began operating in a degraded mode sometime between_ April 13 and August 7, when the daily checks were initiated.

In order to determine the effects of the degraded mode of the monitor, the t'

investigation became more involved. The strip-charts for the new monitor and the charts for the old monitors were checked against any records of work performed and/or releases made to inaure that the cause of any upscale or downscale indications were verified. This was done to insure that no unidentified or unmonitored material was released overboard.

(It should be noted that the old monitors were calibrated and tested on schedule. Although Operations personnel were essentially instructed to disregard the old monitors, their chart outputs are still valuable indications.) This investigation revealed that at no time during the period of February to December was there a perturbation which did not correspond to a release or to work being performed.

4

m Reportable Occurrence Page 3 Report No. 50-219/81-71/01T Since Oyster Creek makes its releases on an uniderJ,ried basis, yet actually determines the concentration of each isoto:ee by sampling, a large margin of conservatism between actual discharge concentrations and the 10 CFR 20 limits is inherent.

However, an additional analysis was performed to verify this.

The liquid release data for every release made f rom February 1 to December 31 was analyzed, and the two (2) releases with the highest total isotopic concentration were chosen.

For the analysis, the maximum release rate of 200 GPM was used, and the minimum dilution flow of 460,000 GPM was used (even though actual release rates were much lower and actual dilution flows were higher).

The maximum possible concentration in the discharge for each isotope present was calculated, and these concentrations were compared to the limits given in 10 CFR 20, Appendix B, Table II, Column 2.

All of these maximum concentrations were below the 10 CFR 20 limits, with the margin of conservatism being at least a factor of 16 or greater.

These results can also be correlated with the alert and alarm setpoints for the monitor and with the fact that the monitor was reading one-tenth low.

The results of this correlation are that the monitor would have alarmed and automatically halted the release by closing the discharge valve prior to any 10 CFR 20 limits being exceeded.

, Corrective Action The monitor was removed from service for the previously mentioned tests, and during this period, the independent verification of valve lineup and additional samples were performed as required by the Technical Specifications. A new sample chamber has since been installed, and the recorder has been restored to operable status.

The procedures for the monthly test and quarterly calibration have been written and are currently in the review process.

The daily checks are currently being performed.

The double valve lineup verifications and double samples will still be performed until all procedures are reviewed and issued.

On a more general basis, a review of past modifications and Technical Specification changes since July 1980 will be performed to determine if the necessary administrative requirements were met prior to their completion.

Since the time of this modification, a new system was devised which outlines responsibilities for insuring the necessary administrative requirements are addressed (i.e., procedures, surveillance requirements, drawing changes, etc.) prior to the plant assuming control of the system or piece of equipment.

This system will be reviewed to ensure that events of a related nature will not occur.

Failure Data Manufacturer:

_ Victoreen Instrument Division

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