ML20072A771: Difference between revisions

From kanterella
Jump to navigation Jump to search
(StriderTol Bot insert)
 
(StriderTol Bot change)
 
Line 16: Line 16:


=Text=
=Text=
{{#Wiki_filter:e.                                                                                       DM8
{{#Wiki_filter:DM8 e.
                /D C-Commonwealth Edison
/D Commonwealth Edison
  ,            /      ) on's First National Pirza, Chicago, Illino$
) on's First National Pirza, Chicago, Illino$
                        "] Address Reply to: Post Office Box 767
/
((Oj    / Chicago, Illinois 60690 June 3, 1983 Mr. James G. Keppler, Regional Administrator
C-((O
                -  Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
"]
Address Reply to: Post Office Box 767
/ Chicago, Illinois 60690 j
June 3, 1983 Mr. James G. Keppler, Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137


==Subject:==
==Subject:==
Line 28: Line 31:
For your tracking purposes, this deficiency was assigned Number 83-06 for our Byron Station and Number 83-05 for our Braidwood Station.
For your tracking purposes, this deficiency was assigned Number 83-06 for our Byron Station and Number 83-05 for our Braidwood Station.
This letter fulfills the thirty (30) day reporting requirements of 10 CFR 50.55(e) regarding this matter and is considered to be a final report.
This letter fulfills the thirty (30) day reporting requirements of 10 CFR 50.55(e) regarding this matter and is considered to be a final report.
Description of Deficiency The reactor trip breakers and reactor trip bypass breakers at Byron /Braidwood Stations are Westinghouse Model DS-416. Due to a discrepancy in design, there is a potential for misoperation of the undervoltage (UV) attachment in the breakers. The width of the retaining ring on the two pivot shafts of the UV trip (refer to attachment) is not compatible with the width of the groove on the pivot shafts that receives the retaining ring. The groove in the shaft receiving the retaining ring was not increased in width to be consistant with an earlier (1972) retaining ring design change. The new retaining ring is wider than the original design and does not seat properly in the existing grooves.                       This could cause the retaining ring to become disengaged from the pivot shaft and allow the pivot shaft to move laterally and come out of its guide hole.
Description of Deficiency The reactor trip breakers and reactor trip bypass breakers at Byron /Braidwood Stations are Westinghouse Model DS-416.
8306100246 830603                                                   JUN   61 PDR ADOCK 05000454 S                         PDR Y \
Due to a discrepancy in design, there is a potential for misoperation of the undervoltage (UV) attachment in the breakers.
The width of the retaining ring on the two pivot shafts of the UV trip (refer to attachment) is not compatible with the width of the groove on the pivot shafts that receives the retaining ring.
The groove in the shaft receiving the retaining ring was not increased in width to be consistant with an earlier (1972) retaining ring design change.
The new retaining ring is wider than the original design and does not seat properly in the existing grooves.
This could cause the retaining ring to become disengaged from the pivot shaft and allow the pivot shaft to move laterally and come out of its guide hole.
8306100246 830603 JUN 61 PDR ADOCK 05000454 S
PDR Y
\\


  .? ' .
.? '.
Analysis of Safety Implications The deficiency described above increases the potential for misoperation of the DS-416 undervoltage attachment, thereby creating a condition wherein the reactor trip switchgear might not open on automatic demand from the reactor protection system. However, the reactor could be tripped manually by energizing the shunt coil of either reactor trip breaker to prevent any adverse safety consequences.
.' Analysis of Safety Implications The deficiency described above increases the potential for misoperation of the DS-416 undervoltage attachment, thereby creating a condition wherein the reactor trip switchgear might not open on automatic demand from the reactor protection system.
Corrective-Action Westingnouse will supply replacement UV attachments for the DS-416 reactor trip switchgear. The new attachments have modified (widened) grooves te acccmmodate the new retaining rings.
However, the reactor could be tripped manually by energizing the shunt coil of either reactor trip breaker to prevent any adverse safety consequences.
Manufacturing drawings have been revised and quality control procedures modifiad to assure that critical design dimensions are maintained during manufacture. Furthermore, Westinghouse is developing and will implement a procedure for installation of the new attachments on DS-416 reactor trip switchgear in the plant.
Corrective-Action Westingnouse will supply replacement UV attachments for the DS-416 reactor trip switchgear.
The new attachments have modified (widened) grooves te acccmmodate the new retaining rings.
Manufacturing drawings have been revised and quality control procedures modifiad to assure that critical design dimensions are maintained during manufacture.
Furthermore, Westinghouse is developing and will implement a procedure for installation of the new attachments on DS-416 reactor trip switchgear in the plant.
This field installation procedure will provide for proper alignment and interface of the attachment with the breaker trip shaft.
This field installation procedure will provide for proper alignment and interface of the attachment with the breaker trip shaft.
Westinghouse will supply the new UV attachments by October, 1983.
Westinghouse will supply the new UV attachments by October, 1983.
The new UV attachments will be installed and tested prior to fuel load.
The new UV attachments will be installed and tested prior to fuel load.
Please address any questions that you or your staff may have concerning this matter to this office.
Please address any questions that you or your staff may have concerning this matter to this office.
Very truly yours         d#
Very truly yours d2
2
.,7 -
                                            . ,7 -
E. Douglas Swar z Nuclear Licensing Administrator Attachment cc:
E. Douglas Swar z Nuclear Licensing Administrator Attachment cc:   RIII Inspector - Byron RIII Inspector - Braidwood Director of Insp. and Enf.
RIII Inspector - Byron RIII Inspector - Braidwood Director of Insp. and Enf.
U.S. Nuclear Commission Washington, DC       20555 6712N a
U.S. Nuclear Commission Washington, DC 20555 6712N a


                                                                                                  ^
^
  ...' e'. g                                                                                                                       '
... ' e'.
g,Nackmend
g g,Nackmend
* ncervo > rage Ahacymenf
' ncervo > rage Ahacymenf q
                                  '                                    q
.ds:
                        .ds:
v
                            <      v TRIP BAR           \                        pjpg7 T'WAFTJ
,\\
                                                                      ~ ~dd                          *
pjpg7 TRIP BAR T'WAFTJ
                                                                                                              \             [Ff
\\
                                      /                                                                    4),1
[
[
RESET LEVER -
/
' ~ ~dd 1
[
Ff RESET LEVER -
{$I 4),
ROLLER BRAcacET
ROLLER BRAcacET
{$I                                                ~
~
Y                                 N.
Y N.
OPERATING RCD                                                                  -
N
N                ]
]
g           a MOVIN G cogg                                                            7                             -
OPERATING RCD g
                                                                                                                        ,)
a 7
K,                                         '
,)
                                                                                                , %u ..                -
MOVIN G cogg K,
(             cats. ~                                                                                           I Kr.,,.
, %u I
4                ,' s            s'
(
                                                                                              ,',     N s s
cats. ~
                                                                                                                        }.
Kr.,,.
;                                                          -          -                    s   t    ,
}.
                                                      .            s                                         ,
s'
                                                          '                                      s     ,
,', N s 4
                                          <  ,'        \
,' s s
s s                        s l
t s
s g                              -
s s
N     ,    s
s
                                                    -            s j/                                                             s   N e
\\
                                                /               s          -
s l
                                                          ,s                                           N5
s s
                                                                      'yI                   s ,
N s
                                        /                             J l
g j/
s N
s e
s
/
,s N 5
'yI s,
/
J l
t s
t s
WASHER
(
(        j STAfloN HEY coEE         N e'
j WASHER STAfloN HEY coEE N
w
e' w
                                                $          }
}
I e}}
I e}}

Latest revision as of 05:51, 15 December 2024

Final Deficiency Rept Re Westinghouse DS-416 Reactor Trip Switchgear Design Discrepancy.Initially Reported on 830504. Replacement Undervoltage Attachments Will Have Modified, Widened Grooves to Accomodate New Retaining Rings
ML20072A771
Person / Time
Site: Byron, Braidwood, 05000000
Issue date: 06/03/1983
From: Swartz E
COMMONWEALTH EDISON CO.
To: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, 6712N, NUDOCS 8306100246
Download: ML20072A771 (3)
v • d • e


Text

DM8 e.

/D Commonwealth Edison

) on's First National Pirza, Chicago, Illino$

/

C-((O

"]

Address Reply to: Post Office Box 767

/ Chicago, Illinois 60690 j

June 3, 1983 Mr. James G. Keppler, Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

Cyron Station Units 1 and 2 Braidwood Station Units 1 and 2 10 CFR 50.55(e) 30 Day Report DS-416 Reactor Trip Switchgear NRC Docket Nos. 50-454/455 and 50-456/457 06ar MI. Keppler:

On May 4, 1983, the Commonwealth Edison Company Project Engineering Department notified Mr. L. McGregor of your of fice of a deficiency reportable pursuant to 10 CFR 50.55(e) regarding the DS-416 Reactor Trip Switchgear at our Byron and Braidwood Stations.

For your tracking purposes, this deficiency was assigned Number 83-06 for our Byron Station and Number 83-05 for our Braidwood Station.

This letter fulfills the thirty (30) day reporting requirements of 10 CFR 50.55(e) regarding this matter and is considered to be a final report.

Description of Deficiency The reactor trip breakers and reactor trip bypass breakers at Byron /Braidwood Stations are Westinghouse Model DS-416.

Due to a discrepancy in design, there is a potential for misoperation of the undervoltage (UV) attachment in the breakers.

The width of the retaining ring on the two pivot shafts of the UV trip (refer to attachment) is not compatible with the width of the groove on the pivot shafts that receives the retaining ring.

The groove in the shaft receiving the retaining ring was not increased in width to be consistant with an earlier (1972) retaining ring design change.

The new retaining ring is wider than the original design and does not seat properly in the existing grooves.

This could cause the retaining ring to become disengaged from the pivot shaft and allow the pivot shaft to move laterally and come out of its guide hole.

8306100246 830603 JUN 61 PDR ADOCK 05000454 S

PDR Y

\\

.? '.

.' Analysis of Safety Implications The deficiency described above increases the potential for misoperation of the DS-416 undervoltage attachment, thereby creating a condition wherein the reactor trip switchgear might not open on automatic demand from the reactor protection system.

However, the reactor could be tripped manually by energizing the shunt coil of either reactor trip breaker to prevent any adverse safety consequences.

Corrective-Action Westingnouse will supply replacement UV attachments for the DS-416 reactor trip switchgear.

The new attachments have modified (widened) grooves te acccmmodate the new retaining rings.

Manufacturing drawings have been revised and quality control procedures modifiad to assure that critical design dimensions are maintained during manufacture.

Furthermore, Westinghouse is developing and will implement a procedure for installation of the new attachments on DS-416 reactor trip switchgear in the plant.

This field installation procedure will provide for proper alignment and interface of the attachment with the breaker trip shaft.

Westinghouse will supply the new UV attachments by October, 1983.

The new UV attachments will be installed and tested prior to fuel load.

Please address any questions that you or your staff may have concerning this matter to this office.

Very truly yours d2

.,7 -

E. Douglas Swar z Nuclear Licensing Administrator Attachment cc:

RIII Inspector - Byron RIII Inspector - Braidwood Director of Insp. and Enf.

U.S. Nuclear Commission Washington, DC 20555 6712N a

^

... ' e'.

g g,Nackmend

' ncervo > rage Ahacymenf q

.ds:

v

,\\

pjpg7 TRIP BAR T'WAFTJ

\\

[

/

' ~ ~dd 1

[

Ff RESET LEVER -

{$I 4),

ROLLER BRAcacET

~

Y N.

N

]

OPERATING RCD g

a 7

,)

MOVIN G cogg K,

, %u I

(

cats. ~

Kr.,,.

}.

s'

,', N s 4

,' s s

t s

s s

s

\\

s l

s s

N s

g j/

s N

s e

s

/

,s N 5

'yI s,

/

J l

t s

(

j WASHER STAfloN HEY coEE N

e' w

}

I e

Retrieved from "https://kanterella.com/w/index.php?title=ML20072A771&oldid=4413464"