ML17261A120

LER 79-009/01T-0 on 790416:routine Sample of Boron Boric Acid Tank Showed 11.8%.Reactor Power Reduction Started. Caused by Possible Backflow of Makeup Water.Check Valve Replaced

ML17261A120
Person / Time
Site:	Ginna
Issue date:	04/30/1979
From:	Peck C ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML17261A119	List: ML17261A118 ML17261A120 ML17261A121
References
LER-79-009-01T, LER-79-9-1T, NUDOCS 7905040187
Download: ML17261A120 (4)

Text

NRC FORM 386 U. S. NUCLEAR REGULATORY COMMISSION (707 7I 79-009/01T-0 CONTROL BLOCK:

LlCENSEE EVENT REPORT Q1 e

(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

(CAR 1221)

I 6

~01 7 8 9 N Y R E G LICENSEE CODE 1

14 Q20 15 0 0 0 0 0 LICENSE NUMBER 0 0 0 25 Q3 26 4 1 1 LICENSE TYPE 1 1 30 Q4~57 CAT 58 QE CON'T

~0 LQ30 3 0 0 0 2 4 4 1 69 0 4 1 6 7 9Qso 74 75 4 3 0 7 9QR 80 7 8 60 61 DOCKET NUMBER 68 EVENT DATE REPORT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES Q10 Following routine sample of B boric acid storage tank, analysis showed 11.8% boric acid (BA). (T.B. 3.2.3.c) Reactor power reduction was started. After enriching tank contents and analysis showed above 12%, power reduction was stopped.

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~03 80 7 8 9 SYSTEM CAUSE CAUSE COMP. VAI.VE 8

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CODE 10 Q"

CODE E Q12 SUBCODE

~X Q' V A COMPONENT CODE L V E X 64 'C SUBCODE QE SUBCODE L~J 20 Qo TYPE'O.

7 11 12 13 18 19 SEOUENTIAL OCCURRENCE REPORT REVISION EVENT YEAR REPORT NO. CODE Q

LER/RO REERRE ~79 21 22 Q23

~00 24 9

26 Qx 27

~01 28 29 QT 30 Q31 Qo ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRDP PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS Q22 SUBMITTED FORM bUB. SUPPLIER MANUFACTURER LXJQ13 L~JQ10 L~JQ20 ~ZQ>> O O O 3 ~XQ23 ~TQ24 ~AQ23 R 3 4 O Qo 33 34 35 36 37 40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 27 0 Possible back flow of reactor makeup water (RMW) through blender BA s upply check valve. Initial investigation and corrective action was checking closed RMW valves to BA pumps. After similar event (see LER 79-010) manual valve in blender BA supply line was closed, and sample frequency increased to every 12 hr. Check valve was replace wit qua ied spare. Valve is Rockwell Manufacturing Co. 1 in. 1,500 lb. stainless 4 steel spring check valve.

7 8 9 80 CH 3 FACILITY STATUS E Qos ~09

%POWER 2 Q20 OTHER STATUS NA

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~3p METHOD OF DISCOVERY

~BQ31 chemical anal sis DISCOVERY DESCRIPTION Q32 8 9 10 12 13 44 45 46 80 ACTIVITY CONTENT 0

RELEASED OF RELEASE

~ZQ33 ZIQ34 AMOUNT OF ACTIVITY NA Q NA LOCATION OF RELEASE QSB

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7 8 9 10 11 44 45 80 PERSONNEL EXPOSURES NUthBER TYPE DESCRIPTION Q39

~17 7 8

~pp 9

p 11 Q31 ~ZQ33 12 13 NA 80 PE R SO NNE L Ih'JURIES NUMBER DESCRIPTION Q41 7

3 8

~00 9

0 QEo NA 11 12 80 LOSS OF OR DAMAGETO FACILITY TYPE DESCRIPTION Q43

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ZZ 8 9 Q 10 NA 80 PUBLICITY

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. ISSUED

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DESCRIPTION Q NA NRC USE ONLY 8 9 10 68 69 80 ER NAME OF PREPARER Carl H. Peck PDNE.716 546-2700 ext.291-205

Attachment to LER 79-009/01T-0 Rochester Gas and Electric Corporation R. E. Ginna Nuclear Power Plant, Unit No. 1 Docket No. 50-244 On April 16, 1979 at approximately'200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> the Shift Foreman was notified of the chemical analysis which indicated that the "A" boric acid storage tank contained 12.0 wt.-% boric acid solution and the "B" tank, 11.8%, each tank containing a volume of approximately 1,400 gallons. An orderly load reduction was commenced, and batching operations were ini-tiated to restore the tanks to the required specifications. The tanks were within specifications at 1415 hours0.0164 days <br />0.393 hours <br />0.00234 weeks <br />5.384075e-4 months <br /> that day.

As it was suspected that leakage of reactor makeup water to the boric acid tanks was the cause, operations personnel began an investigation of manual valves which could present such a leakage path, and tightened closed valves which are used to supply reactor makeup water to the boric acid system pumps and tanks. The investigation was renewed after a similar event reported as LER 79-010. To check for the possibility of back flow of reactor makeup water from the reactor makeup water storage tank through the blender and the blender boric acid supply check valve, a manual valve in the boric acid supply line was closed. With this valve closed the tank concentrations remained constant. The tank sampling frequency has been increased to once every twelve hours. The check valve was replaced with a qualified spare.

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