ML19210D109

LER 79-074/03L-0:on 791019,reactor Scram Received from High Radiation Signal on Main Steam Line High Radiation Monitors. Caused by Resin Injection from Reactor Water Cleanup Sys.Sys Depressurized

ML19210D109
Person / Time
Site:	Brunswick
Issue date:	11/16/1979
From:	Tollison A CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19210D102	List: ML19210D101 ML19210D109
References
LER-79-074-03L-01, LER-79-74-3L-1, NUDOCS 7911200544
Download: ML19210D109 (3)

Text

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LICENSEE EVENT REPORT CONTROL BLOCK:

1 l l l l l 6

lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 0 i 8 9 ni cl al el pl ll@l o f ol l o LICENSE 14 15 l o alolol NUMBER lolol@l 41111!11ilhl57 CATI 58 @

25 26 LICENSE TYFE JO 7 LICENSEE COOE CGN'T 0 ' SO RCE l0 l S l DOCKET O! -l NUM8ERO I 3 l 2 I 6d5 hl691 I oEVENT l 1 DATE l 4 l 7 I 4 hl75 l l l l l lh 7 8 60 61 14 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h Ml During nor-,1 full cover coeration. a reactor scram was received due to a high l 0 3 1 radiation signal on the Main Steam Line High Radiation Monitors. After the scram,l 0 4 l the nonitors returned to a normal reading and all MSIV's were onened. No stack l O 5 I off gan spikes were seen durine the evolution: however. spikes did occur at the 1 0 6 l ernan 4ne gir ,4,renre nnd the f 1,,y efte ennfene ir eke P4mp nf the scram. Anorox-l O 7 l 4 m e,1, e ..on connnaa hafnvp ehe eer ,.,_ eho fnlinuing n,r,mpterm behaved as indic a tl-

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7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUSCODE COMPONENT CODE SUSCODE SUSCODE O 9 lqlulh lrlTlT lTlP lD !@ Z l@ A @

7 8 9 10 11 12 13 18 19 20

,_ SEQUENTIAL OCCURRENCE REPORT REVISION LER RO EVENT YEAR 7EPORT NO. CODE TYPE No.

O"sVg l237hl aE l_l lgl7l4l lyl lg 3l 22 23 24 26 27 28 29 30 31 32 ACTION FUTURE EFFECT SHUTOOWN ATT ACHM ENT NP R D-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS 22 SUBMITTED FORM bus. SUPPLIER MANUFACTURER Uhd@ U@ Wh 33 34 35 36 3l7 0lll 4 1l40 l4l@ 41 42 4l@ lNl@

43 44 Dl0l5l5l@ 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 1 Ol The c,n=e for the reactor scram was a resin iniection from the RWCU system. The LLL'_J l stm =yara una han, otit of service for aooroximately six hours prior to the scrami i 2 I fnr system -nintenance. Durine this ceriod. it is believed'that the filter cake l LLL1]I arnnnod fen, *ho f41*nr centn-a with r asible air entrainment due to systen leakae4 LLL._J l ' ' - ~ - -sa -,mean,n-a - , - c - ,1ar* *ka pucu system was pressurized and the (cont'd) 7 8 9 80 F ACILITY A METPOOF STATUS *  % POWER OTHERSTATUS [C DISCOVERY OISCOVERY DESCRIPTION 32 1 5 (,Ijh 1lololhl NA l l Al@l Reactor Scram l ACTIVITY CO TENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE M W @ d@l 7 8 9 10 11 NA l 44 45 NA l 8I)

PERSONNEL EXPOSURES p . ,

NUVSER 39 b,l O 1 7 8 9 l O l 0 I n0 lh[,JJTYPE 33

@l DESCRIPTIONNA ft , R n ,

UT1 N'he l 7 i2 80 PERSONNEL INJURIES '

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NUY8ER OESCRIPTION ,

IT R8 9Iololol@l 7 11 12 NA 80 l

LOSS OF OR DAMAGE TO FACILITY

• TYPE CE SCRIP TIO~ ^< 91 2 00 W b@l 7 8 9 10 NA b 80 ISSUE OE SC RiPTION e d

7 8 3 bI 10 inc,1 radio. television, and newspaper l 68 69 IllllllIIIlll5 80 5 NAME OF PREPARER A. C. Tollison, Jr. PHONE: 919-457-9521 2

LER CONTINUATION -- RO# l-79-74:

Facility: BSEP Unit # 1 Event Date: 10-19-79 EVENT DESCRIPTION AND PROBAh:E CONSEQUENCES (Cont'd)

Slight Increase No Change Power (APRM) Core a P

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Vessel Pressure Vessel Level Core Flow "B" Feed Flow "A" Feed Flow Throttle Pressure Total Steam Flow Gross Megawatts Turbine Vibration Events noted during and after the scram were as follows:

1. #1 Diesel Generator did not start on the lov level (-38") initiation signal at the time of the scram.

2. While trying to go into torus cooling and later, shutdown cooling, on "B" RHR heat exchanger, no a T could be developed across the heat exchanger.

3. After being used intermittently throughout the day for ves cl level control, the RCIC turbine could not be started on the afternoon of the scram.

4. Vessel chemistry exceeded 2 umho for approxtsately 31.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />, reaching a maximum value of 6.63 umho.

5. The CRD scram discharge volume drain line was found to have several pipe supports damaged from an apparent water hammer event. .

Technical Specifications 6.9.1.9b l j '/ 4J ,a s

-3 LER CONTINUATION - RO# l-79-74 Facility: BSEP Unit # 1 Event Date: 10-19-79 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (Cont'd)

RWCU pump was started. Approximately one minute later, the reactor scrammed.

Resin injected into the vessel caused a change in coolant viscosity and surface tension resulting in flow and pressure disturbances. This imbalance in vessel chemistry results in a release of N-16 which carries over with the steam. The N-16 high energy gamma caused the scram.

~

The faLI.ure of the #1 Diesc1 Generator was due to a split metallic bellows on the lube oil diverting valve actuator, causing a loss of control air.

The diverting valve actuator was replaced with a new vender modified design on all diesel generators. Diesel generator control air pressure has been added to the auxiliary operators Daily Surveillance Report to be checked once ..

per shift.

The anti-rotation device on the RHR heat exchanger inlet valve F047B allowed the stem to rotate without moving the valve disk. The anti-rotation device was adjusted and the valve tested satisfactorily. This is considered an isolated event.

Disassembly of the RCIC steam exhaust check valve showed that the stud and nut on the back of the disk had broken and the disk had separated from the hinge and had lodged in the valve inlet. A new valve has been ordered and will be installed upon arrival. Engineering has been tasked to determine the cause of the failure.

Vessel conductivity increase to 6.63 umho was due to the resin injection and resin breakdown due to temperature and neutron flux. The vessel was cleaned to less than 2 gmho in approximate'ly 31.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. Operating Procedure 14, RWCU, has been revised to direct the RWCU effluent to the condenser after precoating or an. extended shutdown until a chemical analysis is run on the effluent.

Also, the revision requires that (1) double valve isolation of the filter /

demineralizer be used when going.co " Hold / Start", (2) always backwash and precoat the filters when RWCU has been depressurized for greater than thirty minutes, and (3) F042, the RWCU injection valve, will not be opened until the system is completely pressurized and stable.

The CRD scram discharge volume drain line had esveral of its supports damaged by water hammer during the scram. This water hammer is believed to have been caused by the excessively long closing time of the drain line isolation valve.

This problem has been corrected by replacement of the solenoid valve which operates the drain and vent valves. The damaged supports were also replaced and an evaluation is underway to determine if additional support is required.

PT inspections will be conducted on all welds on this line. The drain lines on the other unit were inspected with no detectable damage noted.

i 3'/ 3 ;Jr7/

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