ML20028A531
| ML20028A531 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 11/10/1982 |
| From: | Mcgaughy J MISSISSIPPI POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| AECM-82-541, NUDOCS 8211220266 | |
| Download: ML20028A531 (12) | |
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MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi .$
h atatmidE P. O. B O X 16 4 0. J A C K S O N , M I S S I S S I P P I e3jS 2 0 5~
November 10, 1982 g
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JAMES P. McGAUGHY, JR. .
A$$1STANT VICE PRESIDENT v
Office of Inspection & Enforcement ,~~ -
U. S. Nuclear Regulatory Commission Region II 101 Marietta St., N.W., Suite 3100 Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Regional Administrator
Dear Mr. O'Feilly:
SUBJECT:
Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-13 File 0260/L-835.0 ECCS Injection Special Reports
Reference:
Injection Report No. E12A/01, E22/01, and E22/02 AECM-82/541 ECCS injections occurred on August 13, 1982 and August 14, 1982.
T.S.3.5.1.h requires a Special Report be prepared and submitted pursuant to T.S.6.9.2 within 90 days describing the circumstances of the actuation and the total accumulated actuation cycles to date. Attached for your review are ECCS Injection Special Reports No. E12A/01, E22/01, and E22/02.
Yours ruly,
}, ft (w JPM: sap [M g7 Attachments f f A (,n M p-cc: Mr. N. L. Stampley (w/a)
Mr. R. B. McGehee (w/o)
Mr. T. B. Conner (w/o)
Mr. G. B. Taylor (w/o)
Mr. Richard C. DeYoung, Director (w/a)
Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 ~
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- @,D0k' Document Control Desk (w/a) bT ph h U. S. Nuclear Regulatory Commission Washington, D. C. 20555 8211220266 821110 PDR ADOCK 05000416 S PDR Member Middle South Utilities System
. Att: chm:nt A AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E12A/01 (SYS MPL & SUB/ SEQ. NO.) Page 1 of 4 REPORT DATE 10/28/82 REPORT BY Eennis E. Cathey SECTION I - GENERAL INFORMATION INJECTION DATE/ TIME: 8/13/82 21:04 INJECTION DURATION: Approx. 5 minutes PLANT STATUS:
PARAMETER BEFORE INJECTION AFTER INJECTION RX POWER 0 MWT 0 MWT RX POWER 0 MWE O MWE RX PRESSURE O PSIG 0 PSIG RX TEMP Approx. 75 F Approx. 75 F RX LEVEL Approx. 500 IN 670 IN (Vessel Zero)
CST LEVEL Approx. 19-0 FT-IN Approx. 19-0 FT-IN CST TEMP 80-90 F 80-90 F SUP. POOL LEVEL 20-0 FT-IN 19-4 FT-IN SUP. POOL TEMP 78 F 78 F DRYWELL PRESS 0 PSIG 0 PSIG RX MODE SW. POS. Refuel Refuel INJECTION INITIATION AUTO: LOW RX WATER LEVEL? No HIGH DRYWELL PRESSURE? No OTHER? (EXPLAIN - BRIEFLY) Yes, due to false low reactor water level signal.
MANUAL: (REASON - BkIEFLY) NA I
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Attachment A
'AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E12A/01 Page 2 of 4 INJECTION TERMINATION ,
AUTO: (REASON - BRIEFLY) NA MANUAL: (REASON'- BRIEFLY) Correct water' level verified.
SECTION II - REPORTING OF INJECTION (NAME/ TIME /DATE)
OPS SUPT: Gil Johnson /21:30/8-13-82 DUTY MANAGER: R. A. Ambrosino/21:35/8-13-82 NRC NOTIFIED BY: Charles Hicks /22:02/8-13-82 NRC' CONTACT: Vern Hodgt
! OTHERS:
3 SECTION III - N0ZZLE USAGE FACTOR i
PRIOR TO INJECTION 0
- AFTER INJECTION O ACCUMULATED INJECTIONS TO DATE 1 COMMENTS
- No increase in factor due to the reactor being at ambient
- conditions k
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. Attachm:nt A AECM-82/541 ECCS INJECTION SPECIAL~ REPORT INJECTION NO. E12A/01 Page 3 of 4 SECTION IV - SEQUENCE OF EVENTS' nackground After the initial fuel loading of the reactor, the water level was maintained at just below the top core grid to facilitate the installation of in-vessel vibration strings on the fuel bundles. To allow the low level, the ECCS and Control Rod Drive pumps were tagged out of service and the RPV level instrumentation was valved out. This evolution is allowed per Operating License Condition 2.C.(42).e. This states that prior to going above Operating Condition 5, the provision of T.S.3.3.3 and 3.5.2 may be suspended for the purpose of instrumenting for the vibration monitoring program.
Event On the morning of August 13, 1982, the in-vessel work was completed allowing the water level to be raised to normal levels for the Control Rod Drive friction testing. When the water level reached the normal range, the ECCS and CRD pumps were placed into service at 14:15. The above was completed prior to valving in the RPV level instrumentation which provides the low water level trip signal for ECCS initiation.
For ECCS Division I to initiate on low water level, low level signals must be received from reactor water level channels A and E. When the B21-N091A transmitter was valved in, the A channel tripped on a continuous low level signal. This was cause for half of the low level signal. Shortly thereafter, the N091E transmitter was being valved into service when a one second low level signal spike on channel E occurred. The low level signals occurred as a result of following incorrect sequence when valving the transmitters into service. These actions resulted in a false lor water level trip signal to
'ECCS Division I, causing the auto initiation of LPCI A and LPCS.
LPCS did not start due to a loose connection in the pump motor breaker control circuit. This was subsequently corrected. Although LPCS would have started had it not been for the above problem, the system was officially inoperative at the time due to problems with pressure instrumentation.
The LPCI A pump was manually stopped after verifying the reactor water level was above the low level er!p point.
The causes of this injection were:
- 1. Failure to sequentially follow the procedure used to control reactor water level during this time period, and
- 2. The absence of a procedure to prevent the improper valving in of the transmitters.
- Attachm:nt'A AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E12A/01 Page 4 of 4 SECTION IV - SEQUENCE OF EVENTS (cont.j Corrective Action Corrective actions taken were:
- 1. Training of appropriate personnel as to the requirements for following a procedure in sequence,'and
- 2. The issuance of a procedure for placing ~the level instrumentation into service.
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- Attachm nt B AECM-82/541 z
ECCS INJECTION SPECIAL REPORT INJECTION NO. E22/01 (SYS MPL & SUB/ SEQ. NO.) Page 1 of 3 REPORT DATE: 10/28/82 REPORT BY: Dennis E. Cathey SECTION I - GENERAL INFORMATION INJECTION DATE/ TIME: 8/14/82 / 13:00 INJECTION DURATION: Approx. 2 minutes
< PLANT STATUS:
PARAMETER BEFORE INJECTION AFTER INJECTION RX POWER 0 MWT 0 MWT RX POWER 0 MWE O MWE
. RX PRESSURE O PSIG 0 PSIG RX TEMP Approx. 75 F Approx. 75 F RX LEVEL Above -40 IN Above -40 IN i
(Wide Range)
CST LEVEL Approx. 29-0 FT-IN Less Than 29-0 FT-IN
! CST TENT 80-90 F 80-90 F SUP. POOL LEVEL 19-4 FT-IN 19-4 FT-IN SUP. POOL TEMP 78 F 78 F DRYWELL PRESS 0 PSIG
AUTO: LOW RX WATER LEVEL 7 No HIGH DRYWELL PRESSURE 7' No ,
, s .
OTHER7 (EXPLAIN - BRIEF1h) Due to a f alse low reactor water level signal .
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MANUAL: (REASON - BRIEFLY) NA .
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. Attachmsnt B AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E22/01 Page 2 of 3 INJECTION TERMINATION AUTO: (REASON - BRIEFLY) NA MANUAL: (REASON - BRIEFLY) Correct water level verified.
1 SECTION II - REPORTING OF INJECTION (NAME/ TIME /DATE)
OPS SUPT: Roy Keeton/13:40/8-14-82 DUTY MANAGER: Ken McCoy/13:10/8-14-82 NRC NOTIFIED BY: Gary Lhamon/13:55/8-14-82 i
! NRC CONTACT: Charles Cambell i
- OTHERS
! SECTION III - N0ZZLE USAGE FACTOR PRIOR TO INJECTION O AFTER INJECTION 0 ACCUMULATED INJECTIONS TO DATE 1 COMMENTS: No increase in factor due to the reactor being at ambient conditions.
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r Attachment B AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E22-01 Page 3 of 3 SECTION IV - SEQUENCE OF EVENTS Background -
Previously on August 13, 1982, the reactor water level was raised from just below the upper core grid to a few feet above the main steam nozzles. The level instrumentation for the ECCS and RPS low level trips were valved out during the time the water level was below normal for vibration instrumentation installation on the fuel bundles. This evolution is allowed per Operating License Condition 2.C. (42) .e. This stetes that prior to going above Operating Condition 5, the provision of T.S.3.3.3 and 3.5.2 may be auspended for the purpose of instrumenting for the vibration monitoring program.
While valving the transmitters into service after the water level was returned to normal, difficulty was experienced in obtaining correct level readings.
The plant Instrument and Control Organization (I&C) began to troubleshoot the level instruments to correct the level reading problems. In the early morning hours of August 14, 1982, the B21-N080A, B, C, & D level transmitters were placed into service. The A, B, & C channel readings agreed, however, the D channel read zero. It was concluded that channel D was in-correct and channels A, B, & C indicated the actual reactor water level.
The reference leg for channel D is shared by B21-N073 L&R. B21-N073 L&R provides the low level trip signal for ECCS Division 3 (i.e., the HPCS System).
Event At 13:00, HPCS initiated due to a false low level signal from B21-N073 L&R.
This was determined to be caused by B21-N073 L&R being driven low due to pressure to B21-N080D being raised and lowered during calibration. (B21-N080D and B21-N073 L&R share a common reference leg).
HPCS injection was stopped af ter verification of reactor water level on the other instruments.
It was later determined channels D, L, and R were in fact reading correctly and channels A, B, and C were reading high due to less than full reference l legs. Although water level may have been close to the low level trip at this time, it is believed the calibration activities on Channel D caused the L&R channels to trip due to the initiation occurring at the instant channel D was being calibrated.
Corrective Action The corrective action taken to prevent reoccurrence was to issue a procedure for placing the level instrumentation into service and to revise existing procedures, l
r Attcchment C AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E22/02 (SYS MPL & SUB/ SEQ. NO.) Page 1 of 4 REPORT DATE: 10/28/82 REPORT BY: Dennis E. Cathey SECTION I - GENERAL INFORMATION INJECTION DATE/ TIME: 8/14/82 / 20:37 INJECTION DURATION: Approx 1 minute PLANT STATUS:
PARAMETER BEFORE INJECTION AFTER INJECTION RX POWER 0 MWT 0 MWT RX POWER 0 MWE 0 MWE RX PRESSURE O PSIG 0 PSIG RX TEMP Approx. 75 F Approx. 75 F RX LEVEL Approx. -42 IN Approx. -25 IN (Wide Range)
CST LEVEL 29-0 FT-IN Less Than 29-0 FT-IN CST TEMP 80-90 F -
80-90 F SUP. POOL LEVEL 19-4 FT-IN 19-4 FT-IN SUP. POOL TEMP 78 F 78 F DRYWELL PRESS 0 PSIG 0 PSIG RX MODE SW. POS. Refuel Refuel INJECTION INITIATION AUTO: LOW RX WATER LEVEL? Yes HIGH DRYWELL PRESSURE? No OTHER? (EXPLAIN - BRIEFLY)
MANUAL: (REASON - BRIEFLY) NA
r Attachm;nt C AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E22-02 Page 2 of 4 INJECTION TERMINATION AUTO: (REASON - BRIEFLY) NA MANUAL: (REASON - BRIEFLY) Ry. level was visually verified (Rx.
head removed)
SECTION II - REPORTING OF INJECTION (NAME/ TIME /DATE)
OPS SUPT: Roy Keeton/21:50/8-14-82 DUTY MANAGER: Ken McCoy/22:25/8-14-82 NRC NOTIFIED BY: Larry Moulder /22:15/8-14-82 NRC CONTACT: Charles Cambell OTHERS:
SECTION III - N0ZZLE USAGE FACTOR PRIOR TO INJECTION 0 AFTER INJECTION 0 ACCUMULATED INJECTIONS TO DATE 2 COMMENTS: No increase in factor due to the reactor being at ambient conditions.
F Attachment C AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E22/02 Page 3 of 4 SECTION IV - SEQUENCE OF EVENTS
Background
Previously on Augcat 13, 1982, the reactor water level was raised from just below the upper core grid to a few feet above the main steam nozzles. The level instrumentation for the ECCS and RPS low level trips were valved out -
during the time the water level was below normal for vibration instrumentation installation on the fuel bundles. This evolution is allowed per Operating License Condition 2.C.(42).e. This states that prior to going above Operating Condition 5, the provision of T.S.3.3.3 and 3.5.2 may be suspended for the purpose of instrumenting for the vibration monitoring program.
While valving the transmitters into service af ter the water level was returned to normal, difficulty was experienced in obtaining correct level readings.
The plant Instrument and Control Organization (I&C) began to troubleshoot the level instruments to correct the problems.
With the water level in the RPV above the upper instrument taps, it was decided to back fill the instrument reference legs through the taps. In order to back fill the reference legs, draining of the reference lines from the instrument drain connection was initiated to avoid air being trapped in the reference lines. (A level transmitter with its reference leg less than filled will indicate higher than actual level). Shortly before this, the Recctor Water Cleanur Lyr. tem was aligned to reject water from the vessel causing the vessel water level to drop below the instrument taps.
In the early morning hours of August 14, 1982, the B21-N080A, B, C, & D level transmitters were placed into service. The A, B, & C channels read near normal, however, the D channel read zero. It was incorrectly concluded that channel D was in error and channels A, B, & C indicated the actual reactor water level.
The reference leg for channel D is shared by B21-N073 L&R. B21-N073 L&R provides the low level trip signal for ECCS Division 3, i.e., the HPCS system.
It was later determined channel D and B21-N073 L&R were actually indicating the correct vater level. Chauncls A, B. & C were being used for level indication but were reading high due to unfilled reference legs.
Fvent At 20:20 the HPCS system was initiated by a true low reactor water level signal from B21-N073 L&R. It was unknown at this time that reactor water level had actually dropped below the ECCS low level trip. This was due to the high reading channels A, B, & C being used to determine reactor water level.
The HPCS pump was manually stopped af ter the water level was visually verified to be well above the low level trip.
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Attachment C AECM-82/541 ECCS INJECTION SPECIAL REPORT INJECTION NO. E22/02 Tage 4 of 4 SECTION IV - SEQUENCE OF EVENTS (cont.)
Corrective Action To prevent this problem in the future, a procedure was developed and issued for properly filling and venting the reference legs on level instruments.
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