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: 1. Abnormal Occurrence Report No. 50-313/74-9 | : 1. Abnormal Occurrence Report No. 50-313/74-9 | ||
: 2. Report Date: 10/25/74 3. Occurrence Date: 10/17/74 | : 2. Report Date: 10/25/74 3. Occurrence Date: 10/17/74 | ||
: 4. Facility: Arkansas Nuclear One-Unit 1 Russe 11ville, Arkansas | : 4. Facility: Arkansas Nuclear One-Unit 1 Russe 11ville, Arkansas | ||
. 5. | . 5. | ||
Identification of Occurrence: Crack in the socket weld on reactor coolant drain line (CCA-13-1-1-1/2) located between "B" steam generator and "B" reactor coolant pump. The socket weld is located just upstream of Valve RitD-8B a | Identification of Occurrence: Crack in the socket weld on reactor coolant drain line (CCA-13-1-1-1/2) located between "B" steam generator and "B" reactor coolant pump. The socket weld is located just upstream of Valve RitD-8B a | ||
: 6. Conditiv.s Prior to Occurrence: | : 6. Conditiv.s Prior to Occurrence: | ||
Steady-State Power X Reactor Power ~ | Steady-State Power X Reactor Power ~ | ||
1669 Wth Ilot Standby Net. Output 550 We | 1669 Wth Ilot Standby Net. Output 550 We Cold Shutdown Percent of Full. Power 65 % | ||
Cold Shutdown Percent of Full. Power 65 % | |||
Refueling Shutdown Routine Startup Operation O | Refueling Shutdown Routine Startup Operation O | ||
Routine Shutdown ' | Routine Shutdown ' | ||
Operation , | Operation , | ||
Load Changes During Routine Power Operation . | Load Changes During Routine Power Operation . | ||
Other (Specify) | Other (Specify) 7 Description of Occurrence: - | ||
7 Description of Occurrence: - | |||
1 | 1 | ||
* A one (1) hour leak rate calculation, indicating a 2.15 gpm leakage, was completed at 1245 on October 17,~1974. An immediate investigation com-menced. An entry was made into the reactor building and a leak was four.d in the vicinity of the cold leg drain on loop 8, "B" reactor coolant pump. 3 At that time, it was r.ot possible to identify an exact cause of leakage, whether it was a defective weld, valve bonnet leak, packing, etc. Load reduction and shutdown commenced. | * A one (1) hour leak rate calculation, indicating a 2.15 gpm leakage, was completed at 1245 on October 17,~1974. An immediate investigation com-menced. An entry was made into the reactor building and a leak was four.d in the vicinity of the cold leg drain on loop 8, "B" reactor coolant pump. 3 At that time, it was r.ot possible to identify an exact cause of leakage, whether it was a defective weld, valve bonnet leak, packing, etc. Load reduction and shutdown commenced. | ||
At hot shutdown, a leak was found in the coupling to 1-1/2 inch pipe t. eld of the drain. At that time, the situation was identified as an abnormal ' | At hot shutdown, a leak was found in the coupling to 1-1/2 inch pipe t. eld of the drain. At that time, the situation was identified as an abnormal ' | ||
degradation of the Reactor Coolant Pressure Coundary, s / | degradation of the Reactor Coolant Pressure Coundary, s / | ||
%) | %) | ||
800415073'7 . | 800415073'7 . | ||
July 5, 1974 NSP-10, Rev. O Page 1 of 3 | July 5, 1974 NSP-10, Rev. O Page 1 of 3 | ||
+ ~l | + ~l | ||
\~_a' Abnormal Occurrence Report No. 50-313/74-9 Sheet 2 | \~_a' Abnormal Occurrence Report No. 50-313/74-9 Sheet 2 | ||
: 8. Designation of Apparent Cause of Occurrence: | : 8. Designation of Apparent Cause of Occurrence: | ||
Design Procedure | Design Procedure bbnufre.ture Unusual Service Condition Including Installation / Environmental Construction Component Failure Operator __ | ||
Other (Sptsify) X Examination of the affected area was conducted by a qualified metal-lurgist, a consultant from Bechtel Engineering. A check of ferrite content of the weld revealed no abnormalities. A dimensional check of the clearance required for the fit up of a socket type weld was dona after the weld was ground out. This check revealed a more than adequate clearance between the coupling and the pipe. The existence of fatigue stress is being considered. Vibration readings were taken | |||
bbnufre.ture Unusual Service Condition Including Installation / Environmental Construction Component Failure Operator __ | |||
Other (Sptsify) X | |||
Examination of the affected area was conducted by a qualified metal-lurgist, a consultant from Bechtel Engineering. A check of ferrite content of the weld revealed no abnormalities. A dimensional check of the clearance required for the fit up of a socket type weld was dona after the weld was ground out. This check revealed a more than adequate clearance between the coupling and the pipe. The existence of fatigue stress is being considered. Vibration readings were taken | |||
('"'N for further analysis to determine the -possible existence of fatigue stress failure. -- | ('"'N for further analysis to determine the -possible existence of fatigue stress failure. -- | ||
: 9. Analysis of Occurrence: | : 9. Analysis of Occurrence: | ||
There were no safety implications or haz:rd to the health and safety of plant per;onnel or the public, due to prompt identification of the Icak and cooldown to cold shutdown conditions. 2 | There were no safety implications or haz:rd to the health and safety of plant per;onnel or the public, due to prompt identification of the Icak and cooldown to cold shutdown conditions. 2 | ||
~ | ~ | ||
s | s | ||
~ | ~ | ||
: 10. Corrective Action: | : 10. Corrective Action: | ||
The socket weld filler material on the affected weld was completely '; | The socket weld filler material on the affected weld was completely '; | ||
Line 83: | Line 56: | ||
Qualified welders, working under a QA program, were used to p<:rform | Qualified welders, working under a QA program, were used to p<:rform | ||
* this repair. ANO QA/QC inspectors witnessed the entire repair. A leak test was performed with no discrepancies noted. - | * this repair. ANO QA/QC inspectors witnessed the entire repair. A leak test was performed with no discrepancies noted. - | ||
1 i | 1 i | ||
7s ) | 7s ) | ||
\ | \ | ||
%J | %J | ||
: i. July 5, a.t NSP-10, Rev. O Page 2 of 3 -i l | |||
: i. July 5, a.t NSP-10, Rev. O Page 2 of 3 -i | |||
l | |||
~ | ~ | ||
: e. . | : e. . | ||
l' | l' | ||
Line 108: | Line 69: | ||
Sheet 3 | Sheet 3 | ||
: 11. Failure Mta: | : 11. Failure Mta: | ||
The three other similar welds on drain lines in the reactor coolant system were visually checked _ with no indications noted. A further analysis of the situation is required to determine if the additional investigation is necessary. The results are to be forwarded upon availability. | The three other similar welds on drain lines in the reactor coolant system were visually checked _ with no indications noted. A further analysis of the situation is required to determine if the additional investigation is necessary. The results are to be forwarded upon availability. | ||
- j 12 Reviews and Approvals: | |||
- j | |||
12 Reviews and Approvals: | |||
Reviewed and Approved by: Plant Safety Committee Yes (X) No ( ) | Reviewed and Approved by: Plant Safety Committee Yes (X) No ( ) | ||
Plant Superintendent | Plant Superintendent | ||
Line 125: | Line 81: | ||
Approved by ' # / M -,- ,f .,,[ [ Date: / 8 - Z s '- 7t / | Approved by ' # / M -,- ,f .,,[ [ Date: / 8 - Z s '- 7t / | ||
/ a/fet "Re'vla Co 15e ' | / a/fet "Re'vla Co 15e ' | ||
g | g | ||
~' ' | ~' ' | ||
Approved by- ' | Approved by- ' | ||
fnager of htfc' lear ServGs Date: /0/ I | fnager of htfc' lear ServGs Date: /0/ I | ||
/ /Y | / /Y | ||
~2 Approved by: h'72,','p/ , ,/mf' Date: | ~2 Approved by: h'72,','p/ , ,/mf' Date: | ||
/ | / | ||
Director of Power Prod:.tction h"- 1s- 7f Approved by: ] | Director of Power Prod:.tction h"- 1s- 7f Approved by: ] | ||
)- Date: /[ ' | )- Date: /[ ' | ||
M Senior Vice Prdsident ~ | M Senior Vice Prdsident ~ | ||
t | t | ||
! 4 | ! 4 NM | ||
NM | |||
. ~ | . ~ | ||
July S, 1974 NSP-10, Rev. O | July S, 1974 NSP-10, Rev. O Pace t of 7 | ||
Pace t of 7 | |||
_ -}} | _ -}} |
Latest revision as of 18:19, 18 February 2020
ML19326B388 | |
Person / Time | |
---|---|
Site: | Arkansas Nuclear |
Issue date: | 10/25/1974 |
From: | Cavanaugh W, Phillips J, Rueter D ARKANSAS POWER & LIGHT CO. |
To: | |
Shared Package | |
ML19326B382 | List: |
References | |
NUDOCS 8004150757 | |
Download: ML19326B388 (4) | |
Text
.
w/
- 1. Abnormal Occurrence Report No. 50-313/74-9
- 2. Report Date: 10/25/74 3. Occurrence Date: 10/17/74
. 5.
Identification of Occurrence: Crack in the socket weld on reactor coolant drain line (CCA-13-1-1-1/2) located between "B" steam generator and "B" reactor coolant pump. The socket weld is located just upstream of Valve RitD-8B a
- 6. Conditiv.s Prior to Occurrence:
Steady-State Power X Reactor Power ~
1669 Wth Ilot Standby Net. Output 550 We Cold Shutdown Percent of Full. Power 65 %
Refueling Shutdown Routine Startup Operation O
Routine Shutdown '
Operation ,
Load Changes During Routine Power Operation .
Other (Specify) 7 Description of Occurrence: -
1
- A one (1) hour leak rate calculation, indicating a 2.15 gpm leakage, was completed at 1245 on October 17,~1974. An immediate investigation com-menced. An entry was made into the reactor building and a leak was four.d in the vicinity of the cold leg drain on loop 8, "B" reactor coolant pump. 3 At that time, it was r.ot possible to identify an exact cause of leakage, whether it was a defective weld, valve bonnet leak, packing, etc. Load reduction and shutdown commenced.
At hot shutdown, a leak was found in the coupling to 1-1/2 inch pipe t. eld of the drain. At that time, the situation was identified as an abnormal '
degradation of the Reactor Coolant Pressure Coundary, s /
%)
800415073'7 .
July 5, 1974 NSP-10, Rev. O Page 1 of 3
+ ~l
\~_a' Abnormal Occurrence Report No. 50-313/74-9 Sheet 2
- 8. Designation of Apparent Cause of Occurrence:
Design Procedure bbnufre.ture Unusual Service Condition Including Installation / Environmental Construction Component Failure Operator __
Other (Sptsify) X Examination of the affected area was conducted by a qualified metal-lurgist, a consultant from Bechtel Engineering. A check of ferrite content of the weld revealed no abnormalities. A dimensional check of the clearance required for the fit up of a socket type weld was dona after the weld was ground out. This check revealed a more than adequate clearance between the coupling and the pipe. The existence of fatigue stress is being considered. Vibration readings were taken
('"'N for further analysis to determine the -possible existence of fatigue stress failure. --
- 9. Analysis of Occurrence:
There were no safety implications or haz:rd to the health and safety of plant per;onnel or the public, due to prompt identification of the Icak and cooldown to cold shutdown conditions. 2
~
s
~
- 10. Corrective Action:
The socket weld filler material on the affected weld was completely ';
ground out. The 1-1/2 inch pipe was reinserted in the socket and a single root pass was made. The surface of the coupling and the single root pass were dye penetrant checked with no indications evident.
Qualified welders, working under a QA program, were used to p<:rform
- this repair. ANO QA/QC inspectors witnessed the entire repair. A leak test was performed with no discrepancies noted. -
1 i
7s )
\
%J
- i. July 5, a.t NSP-10, Rev. O Page 2 of 3 -i l
~
- e. .
l'
/
Abnormal Occurrence Report No.
Sheet 3
- 11. Failure Mta:
The three other similar welds on drain lines in the reactor coolant system were visually checked _ with no indications noted. A further analysis of the situation is required to determine if the additional investigation is necessary. The results are to be forwarded upon availability.
- j 12 Reviews and Approvals:
Reviewed and Approved by: Plant Safety Committee Yes (X) No ( )
Plant Superintendent
\ ) Yes (X) No ( )
V ._
Reference:
JWA-621 Date: 10/24/74 Reviewed by Date: O f (
Licensing Supervisor 3
Approved by ' # / M -,- ,f .,,[ [ Date: / 8 - Z s '- 7t /
/ a/fet "Re'vla Co 15e '
g
~' '
Approved by- '
fnager of htfc' lear ServGs Date: /0/ I
/ /Y
~2 Approved by: h'72,','p/ , ,/mf' Date:
/
Director of Power Prod:.tction h"- 1s- 7f Approved by: ]
)- Date: /[ '
M Senior Vice Prdsident ~
t
! 4 NM
. ~
July S, 1974 NSP-10, Rev. O Pace t of 7
_ -