05000338/LER-1980-069-03, /03L-0:on 800801,while Operating in Mode 1 at 100% Power,Sample Analysis Indicated Boron Concentrations in Excess of Tech Spec Limit.Caused by Stratification of Boric Acid in Either Accumulator or Makeup Source (RWST)

/03L-0:on 800801,while Operating in Mode 1 at 100% Power,Sample Analysis Indicated Boron Concentrations in Excess of Tech Spec Limit.Caused by Stratification of Boric Acid in Either Accumulator or Makeup Source (RWST)

ML19331D836
Person / Time
Site:	North Anna
Issue date:	08/27/1980
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19331D834	List: 05000338/LER-1980-069, Forwards LER 80-069/03L-0 05000338/LER-1980-069-03, /03L-0:on 800801,while Operating in Mode 1 at 100% Power,Sample Analysis Indicated Boron Concentrations in Excess of Tech Spec Limit.Caused by Stratification of Boric Acid in Either Accumulator or Makeup Source (RWST)
References
LER-80-069-03L, NUDOCS 8009030632
Download: ML19331D836 (2)

LER-1980-069, /03L-0:on 800801,while Operating in Mode 1 at 100% Power,Sample Analysis Indicated Boron Concentrations in Excess of Tech Spec Limit.Caused by Stratification of Boric Acid in Either Accumulator or Makeup Source (RWST)

Event date:
Report date:
3381980069R03 - NRC Website

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U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT O

CONTROL BLOCK / / / / / / / (1) (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

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LICENSEE CODE LICENSE NUMBER LICENSE TYPE CAT

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DOCKET NUMBER EVENT DATE REPORT DATE

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EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (10)

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On August I and 8, 1980, while eperating in Mode 1 at 100% power, sample analy-/

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/__ sis of "B" SI accumulator indicated a boron concentration in excess of the 2100/

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ppm Technical Specification limit (2143 and 2138 ppm boren respectively).

Be- /

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cause allowable boron concentrations were restored to the accumulator prior to /

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expiration of the specified time interval for the limiting condition for opera-/

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tion, the public health and safety were not affected. Reportable pursuant to /

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T.S. 6.9.1.9.b.

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SYSTEM

CAUSE

CAUSE COMP.

VAIVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUECODE

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SEQUENTIAL OCCURRENCE REPORT REVISION LEP/R0 EVENT YEAR REPORT NO.

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ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTURER

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CAUSE DESCRIPTIOF AND CORRECTIVE ACTIONS (27)

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The high sample concentration is believed to have been caused by stratification /

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of boric acid in either the accumulator or the makeup source (RWST). Correc- /

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tive action was to drain and makeup to the tank until a satisfactory sample was/

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obtained.

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FACILITY METHOD OF DISCOVERY DESCRIPTION (32)

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Periodic Sampling

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NA ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35)

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PERSONNEI. EXPOSURES NUMBER TYPE DESCRIPTION (39)

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PERSONNEL INJURIES NUMBER DESCRIPTION (41)

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LOSS OF OR DAMAGE TO FACILITY G3)

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DESCRIPTION

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PUBLICITY ISSUED DESCRIPTION (45)

NRC USE ONLY l

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NAME OF PREPARER W. R. CARTWRIGHT PHONE (703) 894-5151 l

8009030f Q

Virginia Electric and Power Company North Anna Power Station, Unit #1 Attachment: Page 1 of 1 Docket No. 50-338 Attachment to LER 80-069/03L-0

Description of Event

During steady state operation in Mode 1, sample analysis of "B" safety injection accumulator on August 1 and 8, 1980, indicated a boron concentration in excess of the 2100 ppm Technical Specification 10mit.

Results were 2143 ppm and 2138 ppm boron respectively. Both occurrences are contrary to T.S. 3.5.1.c and reportable pursuant to T.S. 6.9.1.9.b.

Probable Consequences of Event The operability of each RCS accumulator ensures that a sufficient volume of borated water will be immediately forced into the reactor core through each of the cold legs in the event the RCS pressure falls below the pressure of the accumulators. This initial surge of water into the core provides the initial cooling mechanism during large RCS pipe rup-tures. The concentration of boric acid in the RCS accumulators is maintained within an operating band of 1900 to 2100 ppm boron. This limit ensures that the assumptions used for accumulator injection in the safety analysis are met.

Because "A" and "C" accumulators remained operable and acceptable "B" accumulator chemistry was restored prior to expiration of the specified time interval for the limiting condition for operation, the health and safety of the general public were not affected.

Cause of Event

l The high boron concentrations in the "B" accumulator samples is believed to have been caused by stratification of boric acid in either l

the accumulator itself or the water makeup source (RWST).

Immediate Corrective Action

Correct accumulator boron concentrations were restored by lowering the tank level and refilling from the Unit 2 refueling water storage tank.

I Scheduled Corrective Action There are no scheduled corrective actions required.

Actions Taken to Prevent Recurrence Prior to each accumulator solution volume increase, the refueling water storage tank providing the makeup will be thoroughly recirculated using the quench spray pumps.

Generic Implications This problem is generic in nature in that uncirculated tanks con-taining borated water, such as the accumulators, are always susceptable to stratification.