ML20210E246: Difference between revisions

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#REDIRECT [[IR 05000295/1986008]]
{{Adams
| number = ML20210E246
| issue date = 03/24/1986
| title = Insp Rept 50-295/86-08 on 860312-13.No Violation or Deviation Noted.Major Areas Inspected:Plant Trips
| author name = Muffett J, Westberg R
| author affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
| addressee name =
| addressee affiliation =
| docket = 05000295
| license number =
| contact person =
| document report number = 50-295-86-08, 50-295-86-8, NUDOCS 8603270289
| package number = ML20210E241
| document type = INSPECTION REPORT, NRC-GENERATED, INSPECTION REPORT, UTILITY, TEXT-INSPECTION & AUDIT & I&E CIRCULARS
| page count = 3
}}
See also: [[see also::IR 05000295/1986008]]
 
=Text=
{{#Wiki_filter:.
.
                            U.S. NUCLEAR REGULATORY. COMMISSION
                                          REGION III
    Report No. 50-295/86008(DRS)
    -Docket No. 50-295                                              License No. DPR-39
    Licensee: Commonwealth Edison Company
                  P.O. Box 767
                  Chicago, IL 60690
    Facility Name: Zion Nuclear Power Station, Unit 1
    Inspection At: Zion, IL
    Inspection Conducted: March 12-13, 1986
    Inspector:    R. A. Westberg                                    3/      M
                                                                    Date
                  % CL W
    Approved By:    J. W. Muffett, Chi                              b/z4 /gg
                    Plant Systems Section                          Date
    Inspection Summary
    Inspection on March 12-13, 1986 (Report No. 50-295/86008(ORS))
    Areas Inspected: Routine, announced inspection by one regional inspector of
    plant trips - safety system challenges.    It was conducted in accordance with
    NRC Inspection Procedure No. 93702.
    Results: No violations or deviations were' identified.
                8603270299 e60324
              PDR
              O      ADOCK 05000295
                                  PDR
 
    .
  .
                                                DETAILS
      1. Persons Contacted
        Conro nweal th_E_d i s on Compa ny_( C Ecol
'
        *G.  Plim1, Station Manager
        *E. Fuerst, Superintendent Production
        *W. Stone. Quality Assurance Supervisor
        *A. Amoroso, Technical Staff Group Leader, Electrical
          M. Bailey, Technical Staff Engineer
        USNRC
        *J. Kish, Resident Inspector
        * Indicates those attending the exit meeting on March 13, 1986.
      2. Review of Reactor Trip _ Caused _ by_1B_ Reac_ tor Trip Breaker
        The purpose of this inspection was to review the facts relative to the
        reactor trip on March 13, 1986. This review also included the excessive
!
        response time incident of March 3,1986, procedure reviews, interviews
        with involved personnel, and inspection of the IB reactor trip breaker
        (RTB).
        a.    Documents Reviewed
              (1) Maintenance Procedure No. E015-1, " Reactor Trip Breaker
                      Maintenance," Revision 6.
                (2) Test Procedure No. PT-5, " Reactor Protection Logic,"
                      Revision 14
                (3) Schematic Diagram No. 22E-1-4884, " Reactor Trip Switchgear
                      Breaker," Revision J.
          b.    Inspection Results
              The inspector's review of the procedures, the RTB schematic, and
                interviews with involved personnel indicated that the reactor trip
              was caused by the turbine trip which resulted when cell switch
              No. 52h/RTB failed to open when the IB RTB was ir. properly racked
                into place. When the bypass breaker was racked out to place the
                IB RTB back in service, continuity through cell switch 52h enabled
                the circuit logic which shut off the oil supply to the turbine
                control valves causing a turbine trip. The reactor protection logic
                then tripped the reactor 28 milliseconds later.
                The inspector inspected the IB RTB and the switchgear cubicle.
                At the inspector's request, an operator was able to duplicate the
                condition that caused the turbine trip. With the breaker racked in
                and electr:cally functional, it was possible for the breaker to be
                                                    2
 
    ..  . - .  - - _ . .      .      -    -.    .  _-                          _.        .  .    -
2
              ,
      .
A
                                  misaligned so that the cell switch 'ocated in the cubicle behind the
  ,
                                  breaker was not engaged. The function of this cell switch is to
i                                close when the breaker is racked out and to open when the breaker is
                                  racked in place. In this case, the cell switch remained closed even
:
'
                                  thought the breaker was racked in place. Then when the bypass breaker
                                  was racked out, a simila. cell switch closed tripping the turbine.
                                  Based on the review performed by the NRC inspector, this incident
                                  appears to be an example of an isolated personnel error.
!
                                  TheinspectorreviewedtheMarch3,jl986excessiveresponse
.
                                  time incident on the IB RTB, the sub, sequent maintenance, and the
!                                maintenance procedure. This maintenance did not appear to have
i                                any relation to the turbine / reactor trip on March 13, 1986.
i                          No violations or deviations were identified ir. this area,
i                3.        Exit Interview
i
                          The inspector met with licensee representatives in a telephone conference
                          on March 13, 1986, and summarized the purpose, scope, and findings of the
                          inspection. During the inspection, the inspector discussed with licensee
                          personnel the likely informational content of the inspection report with
i                        regard to documents or processes reviewed by the inspector during the
j                          inspection.
l
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a
!
                                                                                                          l
l
!
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3
e
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!
:
i                                                                3
                                                                                                          i
}}

Latest revision as of 09:14, 19 December 2021

Insp Rept 50-295/86-08 on 860312-13.No Violation or Deviation Noted.Major Areas Inspected:Plant Trips
ML20210E246
Person / Time
Site: Zion File:ZionSolutions icon.png
Issue date: 03/24/1986
From: Muffett J, Westberg R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20210E241 List:
References
50-295-86-08, 50-295-86-8, NUDOCS 8603270289
Download: ML20210E246 (3)


See also: IR 05000295/1986008

Text

.

.

U.S. NUCLEAR REGULATORY. COMMISSION

REGION III

Report No. 50-295/86008(DRS)

-Docket No. 50-295 License No. DPR-39

Licensee: Commonwealth Edison Company

P.O. Box 767

Chicago, IL 60690

Facility Name: Zion Nuclear Power Station, Unit 1

Inspection At: Zion, IL

Inspection Conducted: March 12-13, 1986

Inspector: R. A. Westberg 3/ M

Date

% CL W

Approved By: J. W. Muffett, Chi b/z4 /gg

Plant Systems Section Date

Inspection Summary

Inspection on March 12-13, 1986 (Report No. 50-295/86008(ORS))

Areas Inspected: Routine, announced inspection by one regional inspector of

plant trips - safety system challenges. It was conducted in accordance with

NRC Inspection Procedure No. 93702.

Results: No violations or deviations were' identified.

8603270299 e60324

PDR

O ADOCK 05000295

PDR

.

.

DETAILS

1. Persons Contacted

Conro nweal th_E_d i s on Compa ny_( C Ecol

'

  • G. Plim1, Station Manager
  • E. Fuerst, Superintendent Production
  • W. Stone. Quality Assurance Supervisor
  • A. Amoroso, Technical Staff Group Leader, Electrical

M. Bailey, Technical Staff Engineer

USNRC

  • J. Kish, Resident Inspector
  • Indicates those attending the exit meeting on March 13, 1986.

2. Review of Reactor Trip _ Caused _ by_1B_ Reac_ tor Trip Breaker

The purpose of this inspection was to review the facts relative to the

reactor trip on March 13, 1986. This review also included the excessive

!

response time incident of March 3,1986, procedure reviews, interviews

with involved personnel, and inspection of the IB reactor trip breaker

(RTB).

a. Documents Reviewed

(1) Maintenance Procedure No. E015-1, " Reactor Trip Breaker

Maintenance," Revision 6.

(2) Test Procedure No. PT-5, " Reactor Protection Logic,"

Revision 14

(3) Schematic Diagram No. 22E-1-4884, " Reactor Trip Switchgear

Breaker," Revision J.

b. Inspection Results

The inspector's review of the procedures, the RTB schematic, and

interviews with involved personnel indicated that the reactor trip

was caused by the turbine trip which resulted when cell switch

No. 52h/RTB failed to open when the IB RTB was ir. properly racked

into place. When the bypass breaker was racked out to place the

IB RTB back in service, continuity through cell switch 52h enabled

the circuit logic which shut off the oil supply to the turbine

control valves causing a turbine trip. The reactor protection logic

then tripped the reactor 28 milliseconds later.

The inspector inspected the IB RTB and the switchgear cubicle.

At the inspector's request, an operator was able to duplicate the

condition that caused the turbine trip. With the breaker racked in

and electr:cally functional, it was possible for the breaker to be

2

.. . - . - - _ . . . - -. . _- _. . . -

2

,

.

A

misaligned so that the cell switch 'ocated in the cubicle behind the

,

breaker was not engaged. The function of this cell switch is to

i close when the breaker is racked out and to open when the breaker is

racked in place. In this case, the cell switch remained closed even

'

thought the breaker was racked in place. Then when the bypass breaker

was racked out, a simila. cell switch closed tripping the turbine.

Based on the review performed by the NRC inspector, this incident

appears to be an example of an isolated personnel error.

!

TheinspectorreviewedtheMarch3,jl986excessiveresponse

.

time incident on the IB RTB, the sub, sequent maintenance, and the

! maintenance procedure. This maintenance did not appear to have

i any relation to the turbine / reactor trip on March 13, 1986.

i No violations or deviations were identified ir. this area,

i 3. Exit Interview

i

The inspector met with licensee representatives in a telephone conference

on March 13, 1986, and summarized the purpose, scope, and findings of the

inspection. During the inspection, the inspector discussed with licensee

personnel the likely informational content of the inspection report with

i regard to documents or processes reviewed by the inspector during the

j inspection.

l

b

a

!

l

l

!

i

3

e

I

!

i 3

i