ML17192A630
| ML17192A630 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 04/14/1980 |
| From: | Janecek R COMMONWEALTH EDISON CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8004180217 | |
| Download: ML17192A630 (10) | |
Text
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Commonwe. Edison One First National Plaza. Chicago, Illinois Address Reply to: Post Office Box 767 Chicago, Illinois 60690 April 14, 1980 Mr. Darrell G. Eisenhut, Acting Director Division of Operating Reactors U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Dresden Station Units 1, 2, and 3 Quad Cities Station Units l and 2 Failure of Control Rods to Fully Insert on Scram NRC Docket Nos. 50-10/237/249 and 50-254/265 References (a): D. L. Ziemann letter to D. L. Peoples dated January 11, 1980 (b): T. A. Ippolito letter to D. L. Peoples dated January 10, 1980
Dear Mr. Eisenhut:
References (a) and (b) requested additional information concerning failure of control rods to fully insert on a scram at Dresden and Quad Cities Stations.
The referenced letters requested this information for the period from January, 1978 through December, 1979, and indicated that other malfunctions, such as unlatching should be included also.
For Dresden Unit 1,
~ review of the station records indicates that no instances of control rods failing to fully insert during scram or other significant malfunctions were evidenced from January, 1978 until shutdown for the current outage in October, 1978..
The information concerning control rod failures to fully insert during scram and other malfunctions are presented in Attachments l and 2 for Dresden 2 and 3 and Quad Cities l and 2, respectively.
The cause of the control rods to settle to the "02" position following a scram is still believed to be excessive leakage past worn or brdken stop and drive piston seals, causing a hydraulic p
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8004180 21, 1i
Commonwealth Edison Mr. Darrell G. Eisenhut April 14, 1980 Page 2 block on the drives between positions "02" and "00".
This has been confirmed by preliminary results of an investigation by General Electric Co. at Dresden~
No final fix to prevent or reduce seal deterioration has been recommehded to date.
All control rod drives which exhibit the failure to fully insett during scram will continue to'be overhauled during the first refueling outage following their failure.
Please address any additional questions you may have concerning this matter to this office.
One (1) signed original and fifty-nine (59) copies of this transmittal are provided for your use.
3014A Very truly yours, Robert F. Janecek Nuclear Licensing Administrator Boiling Water Reactors
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ATTACHMENT l Dresden Units 2 and 3 Tabulation of Control Rods Failing to Fully Insert Following Scram and Other Malfunctions
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'ATTACHMENT Control Rod Drives observed at position "02" following a scram condition during operation.
Underlined I.D. no. denotes first occurrence durinq that cycle.
DRESDEN UNIT 2 Date of Scram Cycle 6 2-09-78 2-10-78 2-12-78 4-09-78 4-27-78 7 78 7-29-78 7-30-78 9-13-78 10-28-78 2-08-79 D2 Cycle 7 6-12-79 CRD's at Position "02" J-6 (34-23). J-9 (34-35)
J-6, J-9 L-9 (42-35), M-7 (46-27)
E-7 (18-27), J-6, J-9, K-10 (38-39), L-9 B-5 (06-19), E-7, F-11 (22-43), H-4 (30-15};-K-10, L-9 D-11 (14-43), H-4, J-6, J~9, K-4 (38-15), K-10 D-11, _E-8 (18-31), F-11, H-4, J-6, J:9, K-4, K-10, M-7 D-11, E-8, ~2 (26-07), J-4 (34-15), K-5 (38-19), M-7 C-6 (10-23), E-5 (18-19),
E-7, E-8, G-1~26-51), H-4, J-6, J-9, K-4, K-5, K-10, L-9, M-4 (46-15), M-7 B-12 (06-47), E05, E-7, F-8, G-13, H-4, J-6, J-9, K-4, K-10, L-9 C-6, D-11, E-5, E-7, E-8, E-11 (18-43), F-6 (22-23),
F-7 (22-27), F-9 (22-35),
F-11, G-8 (26-31), G-9.
(26-35~G-13, H-4, J-6, J-9, K-4, K-5, K-10, L-4 (42-15), L-9, L-10 (42-39),
M-4, M-7 (28 CRD'a)
C-7 (10-27), E-9 (18-35),
G-4 (26-15)' G-10 (26-39).
_c;-11. (26-l13). !!:".2. (30-15).
J-5 (Jli-19), J-8 (311-)l).
J-T2 (38-47). K-11 (38-43)'
L-12 (42-47)
ATTACHMENT Date of Scram
.02 Cycle 7 7-2 7-79 10-20-79 10-22-79 1-19-80 1-30-80 2-03-80 CRD's at Position "02" B-7 (06-27), E-4 (18-15),
E-6 (18~23), E-10 (18-39),
F-3 (22-11), F-5-(22-19),
G-4, G-6 (26-23), G-10, H-9, J-8, K-9 (38-35), K-11, L-6 (42-25), L-12, M-9 (46-35)
B-7, C-7, D-12 (14-47), E-9, F-5, F-13 (22-51), C-3 (26-l~G-7 (26-27T:-G-11, H-8 (30-31"5: H-9, H-11 (30-43), J-5, J-7 (34-27),
K-8 (38-31), K-11, K-12 (38-43), M-5 (46-19), M-9, N-9 (50-35)
C-7, C-9 (10-35), D-8 (14-31) I D-12, E-9, G-3 '
G-7, G-11, H-6 (30-23), H-8, J-5, J-7, J-13 (34-51), K-8, K-12, N-9 -.-
B-7, E~4, E-10, F-5, F-13, G-4, G-6, H-5 (30-19), H-7 (30-27), H-9, H-11, J-8-, -
K-9, K-11, L-12, M-5, M-9, M-11 (46-43)
B-7, C-5 (10-19), c~7, C-9, D-7 (14-27), D-8, D-12, E-6, E-9, E-10, F-5, F-9 (22-35),
F-12 (22-47); G-~G-4, G-5 (26-19), G-6, G-7, G-9 (26-35), G-10, G-1(:-H-5, H-6, H-7, H-9, H-10 (30-39), H-11, H-14 (30-55T:-J-5, J-7, J-8, J-9 (34-35), K-7 (38-27), K-8, K-9, K-11, K-12, L-6, L-12, M-5, M-9, N-9 B-7, C-5, C-7, C-9, D-7, D-8, D-12, E-3 (18-11),
E~4, E-6, E-9, E-10, E-11 (18-43), F-5, F-8 (22-31)-:C::-3, G-4, G-6, G-7, G-10, G-11, H-5, H-6, H-7, H-8, H-9, H-10, H-11, H-14, J-5, J-6 (34-23), J-7, J-8, J-9, J-13, ~~ ( 34-55)'
K-8, K-11, K-12, L-6, L-12, M-5, M-9, N-6 (50-23), N-9 C-11 (10-43) Uncoupled (56 CH.D's)
ATTACHHENT DRESDEN UNIT 3 Date of Scram Cycle '1 9-02-78 11-18-78 12-09-78 12-12--78 2-16-79 Cycle 6 4 79 5-20-79 6-01-79 6-01-79 9-22-79 9-25-79 10-25-79 11-10-79 12-10-,79 CRD's at Position "02" P-10 (54-39)
L-6 (42-23)
L-6, L-7 (42-27), L-9 (42-3~ N-8 (50-30 J-10 (34-39), L-6, L-7, L-9 L-7 (6 CRD's)
C-7 (10-27), G-8 (26-31),
H-10 (30-39), J-7 (34-2 7),
J-8 (34~31). J-9 (34-35)
C-7, G-8, H-10, J-7, J-8, K-8 (38-31)
C-7, H-10, J-7, J-9, K-8, L-5 (42-19), L-11 (42-43)
G-5 (26-19) Overtravel C-7, F-10 (22-39), H-8 (30-31)-;-H-10, J-7, J-9, K-8, L-11 F-3 (22-11), G-8, J-8, K-1 (38-03), K-7 (38-27), K-9
. (38-35), L-8 (42-31) -
C-7, F-10, G-8, H-8, H-9 (30-35), H-10, J-7, J-8, J~9, K-7, K-8, K-9, K-10 (38-39)
C-7, F-10, G-8, H-8, H-9, H-10, J-6 (34-23), J-7,
. J-8, J-9, K-7, K-8, K-9, K-10~ L-5, L-11 C-7, D-7 (14-27), F-10, G-8, H-8,. H-9, H-10, J-6, J-7, J-8, J-9, K-7, K-9, -
K-10, L-5, L-8, L-11, M-6 (46-23), M-8 (46-31)
(23 CRD's)
ATTACHMENT 2 Quad Cities Units l and 2 Tabulation of Control Rods Failing to Fully Insert Following Scram and Other Malfunctions
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Tl\\nr.r:: l UNIT ONE DATE OF CONTROL ROD CONTROL ROD POSITION
. SCRAM POSITION FOLLOWING SCRAM 317179 34-43 02
- 9121 /79 34.;.43 02 42-43 02 30-39 02 18-15 02 11 /29/79 26-19 02 I
30-39 02
)
10-43 02 34-43 02 46-31 02
- 12/11 /79 18-39 02 34-15 02
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14-31 02 I
.26-19 I
02 34-43 02 I
30-39 02 18-15 02 I
42-43 02 I
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DATE OF SCRAM I
- 9/24/79 I
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'T'MT.P. 7 UNIT TWO CONTROL ROD POSITION 50-27 42-27 26-27 CONTROL ROD POSITION FOLLOWING SCRAM 02 02 02 Unit Two CRO failures to latch in at 00 following scram
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2-25-78 3-23-78 Lt-17-78 &
Lt-21-78 10-2-78 Lt-27-79 7-21-79
'T'N3LP. 1 Control Rod Drive Malfunctf6ns Unit Two Control Rod Drive 02-35,experienced a cold scram time of greater than seven (9.28) seconds for 90% insertion.
The cause was found to be a faulty scram inlet valve which was repaired.
The new 90% insertion scram time was 2.03 seconds.
Unit Two Cor.trol Rod Drive 02-35 drifted in to 00 from Lt8 on three seperate occasions.
The cause was found to be a worn diaphragm in an ASCO scram solenoid valve, which allowed arr to leak through the solenoi<; al lowing the scram exhaust valve to momentarily open.
Both ASCO scram valves.on the drive unit were replaced.
Unit 2 Control Rod Drive 50-39 failed to scram during scram timing.
The cause was found to be a malfunction at a scram solenoid valve.
Both scram solemoids were rebuilt, and the rod was successfully timed.
Additional information can be found in LER RO 78-34/03L-O.
Control Rod Drive 06-31 stuck at position 16.
Failure was caused by malfunction of the directional control valve.
The control rod drive was scrammed and electrically disarmed, and both directional control valves (121 & 121) were replaced.
Unit One Control Rod Drive 18-59 failed to latch in at 00, during a sequence exchange, and drifted to 02.
A scram signal was given to 18-59 and the rod latched at 00.
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