ML20009E436

LER 81-046/03L-0:on 810617,pressurizer Level Found Below Setpoint & Chemical Vol & Control Sys Flow Found Exceeding Rated Flow W/Two Charging pumps,11 & 13,running.Caused by Overpressure Condition Due to Relief Valve 13 Lifting

ML20009E436
Person / Time
Site:	Calvert Cliffs
Issue date:	07/17/1981
From:	Junge M, Mahon C BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20009E433	List: ML20009E432 ML20009E436
References
LER-81-046-03L, LER-81-46-3L, NUDOCS 8107280206
Download: ML20009E436 (2)

Text

NRC FOftM 366 U. S. NUCLEAR REGULATORY COMMISSION (7 17) #

LICENSEE EVENT REPORT CONTROL BLOCK: l l l l l l l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 3 6 lo lil 8l 9M I DLICENSEE 7

I C lCODE C I N 14l 1 15l@l 010 l- l LICENSE 010101010 NUMBER l- l010 26l@l411 26 11 1111 LICENSE TYPE JO l@l5 7 CA1 l 68 l@

CON'T IoI1I 7 8 S$$ l 60L l@l610 l 5 l DOCKET 0 l 0 NUMBER l 0 l 311 l 687 l@l 69 0 EVENT l 6 l1DATE l 7 l 811 74 l@l017 75 REPORT l1DATEl 7 l 811 80 l@

EVENT DESCRIPTION AND PROBA 9LE CONSEQUENCES O1o I 012 i L At 0640 during normal operation, letdown flow was found to be 45 gom l

, i O i3, l with two charging pumps running. No. 13 Charging Pump Discharge Relief l l O 14 i l Valve was found open rendering #13 charging pump inoperable (T.S. 3.1. l iO isi l 2.4). No.13 charging pump was secured for two minutes to allow the re. l

, [ O g1 l lief valve to shut. The relief valve remained seated when the pump was i 10171l restarted tenninating the event. LER 81-21 describes a similar event. l I

10181 l 80 7 8 9 DE CODE S EC E COMPONENT CODE SU8C DE St DE O 9 l c l G l@ (j_lh [Z_j@ l V I Al L l V I E l X I@ [J_jh [B_J 19 20 7 8 9 10 11 12 13 18 SEQUENTIAL OCCUR R ENCE REPORT REVISION EVENT YEAR REPORT NC. CODE TYPE NO.

RO h =LE R_221la 11 22l L--J l 01 41 61 1-1 I013I IL I l--J l_2J 32 23 24 26 27 28 29 30 31 T K N AT N ON PI ANT MET HOURS Sd IT FOR 8. SUPP IE MANUF CTURER I Gl@[E_j@ l35 Zl@ l36 Zl@ l 0l 0l 0] 0l W@ W@ l Al@ lC 44 l 7 ] 1l 01@ 47 33 34 3/ 40 di 42 43 i

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h IiIOI I No.13 Charging Pump Relief Valve lifted on actual overpressure condition. l-

i 3 l The valve did not reseat due to incorrect blowdown setting. Valve blow- I

, , i down was set improperly due to an unclear Maintenance Procedure (RELV 3). i

! i, i3, l RELV 3 will be rewritten to provide greater clarity and all Charging l l 3 4 Pump Discharge Relief Valves will be checked for proper blowdown. l 80 7 8 9 ST S  % POWER OTHER ST ATUS IS O RY DISCOVERY DESCRIPTION l l1 Isl W@ l ll 0l Ol@l NA l lA l@l Operator Observation i

' ACTIVITY C TENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELE ASE l

l1 l6 l LZj @ [_Z_j@l NA l l NA l

l PERsONNEt ExPOsOES NUMBER TYPE DEscalpTION NA l

, l i l 71 101010 l@[Z_J@l PERSONNE L INJU IES NUv8ER DesCRieTiONh l

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i a 8 9 1010101@l12 11 NA 80

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' 8107280206 810717 NRC USE ONLY PDR ADOCK 05000317 ,

2 o ,Ssuel @OESCRiPTioNh NA S PDR l lllllll;lllllj 7 8 9 10 68 69 80 5 M. A. Junge/C. R. Mahon (301) 269-4969/4870 o NAME OF PREPARER PHONE: .,

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LER NO. 81-46/3L DOCKET NO. 50-317 LICENSE NO. DPR-53 EVENT DATE 06-17-81 REPORT DATE 07-17-81 ATTACHMENT EVENT DESCRI" TION AND PROBABLE CONSEQUENCES (CONT'D)

On June 17,1981 at 0526, two charging pumps (Nos.11 and 12) were running. The third charging pump, No.13, was started at this time. No.12 charging pump was secured and tagged out shortly af terwards. However, No.13 Charging Pump Discharge Relief Valve (RV-324) lif ted when al'. three charging pumps had been running. At 0640 on June 17, 1981 the Contro'. Room Operator (RCO) noticed pressurizer level 10 inches below its setpoint level and chemical volume and control system flow at 45 gom with two charging pumps running. (Rated flow at one charging pump is 44 gpm). The CRO secured No.13 charging pump for two minutes and restarted it. The discharge relief valve for No.13 charging pump reseated while the pump was stopped. Pressurizer level was returned to tne normal operating band.

QUSE DESCRIPTION AND CORRECTIVE ACTIONS (CONT'D)

The discharge relief valve for No.13 charging pump was removed and examined.

The suspected cause on the relief valve lif ting was an actual overpressure condition. The relief valve did not reseat due to an improper blowdown setting.

Upon investigation of why the relief valve had an improper blowdown setting it was found that the blowdown ring had been incorrectly positioned because Maintenance Procedure RELV 3 was not written correctly. To prevent future occurrences of this nature, Maintenance Procedure RELV 3 will be rewritten to

! enhance its clarity. All Charging Pump Discharge Relief Valves will have their blowdown settings verified. Finally, a test will be performed to observe the l

operation of No.13 charging pump relieve valve. The test will observe discharge I pressure of No.13 charging pump when it is started while No.11 and No.12 charging pumps are already in operation.

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