ML19347E297: Difference between revisions

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       'li        Oj              PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET                          .
       'li        Oj              PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET                          .
1
1
       ._k    . , N!                            P.O. BOX B699                        %) ITI j-}~f3 g,)g                        PHILADELPHI A. PA.19101              [.'
       ._k    . , N!                            P.O. BOX B699                        %) ITI j-}~f3 g,)g                        PHILADELPHI A. PA.19101              [.'
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                                                                                                        --
                                                                                     ,y          <e April 15, 1981            4 j ._.        /
                                                                              '
                                                                                     ,y          <e
                                                                                                    ,
                                                                                                      ,
April 15, 1981            4 j ._.        /
u l ., . -
u l ., . -
l'r . Bo yca H. Grier, Director Of fice of Inspection and Enforcement Region I IIS !!uc lear Regulator y Commission 631 Park Avenue King of Prussia , PA 19406
l'r . Bo yca H. Grier, Director Of fice of Inspection and Enforcement Region I IIS !!uc lear Regulator y Commission 631 Park Avenue King of Prussia , PA 19406
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l were immediately opened fully upon discovery and operability of the remaining 5 transmitter s was verified.            The pressure l
l were immediately opened fully upon discovery and operability of the remaining 5 transmitter s was verified.            The pressure l
;            transmitters involved are PT-2-10-100A, PT-2-10-100C, and PT-2              128.
;            transmitters involved are PT-2-10-100A, PT-2-10-100C, and PT-2              128.
                                                                                .
f s
f s
810 4 2 405VD--                          3          f    f 0fhk
810 4 2 405VD--                          3          f    f 0fhk


_
l Page 2 Probable Consequence of the Occurrence Investigation of the event determined that, all three instruments had been responding normr11y to drywell pressure fluctuations, indicating that the valves were not completely closed. In order to evaluate this possibility, the valves were re-closed to the approximate as found position and 1ccal leak rate tests were per formed at pressure from 0 to 9.7 PSID. Based upon extrapolation of these results to postulated accident conditions within the drywell, calculations were made of the response time of these instr um ents . The results indicate that the instruments would have provided a back up capability although not within the design time frame.
    , -
l
  .
Page 2 Probable Consequence of the Occurrence Investigation of the event determined that, all three instruments had been responding normr11y to drywell pressure fluctuations, indicating that the valves were not completely closed. In order to evaluate this possibility, the valves were re-closed to the approximate as found position and 1ccal leak rate tests were per formed at pressure from 0 to 9.7 PSID. Based upon extrapolation of these results to postulated accident conditions within the drywell, calculations were made of the response time of these instr um ents . The results indicate that the instruments would have provided a back up capability although not within the design time frame.
Sufficient drywell pressure instrumentation remained in service to provide the required RPS, PCIS, and ECCS initiation within system design requirements in normal fashion.
Sufficient drywell pressure instrumentation remained in service to provide the required RPS, PCIS, and ECCS initiation within system design requirements in normal fashion.
Cause of the Event:
Cause of the Event:
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Plots made from these readings since the last ILRT have shown that the three affected instruments have responded normally to dr ywell pr essur e changes .        Thus determination of the valving error, at the time of the occurrence, based upon a review of the          "
Plots made from these readings since the last ILRT have shown that the three affected instruments have responded normally to dr ywell pr essur e changes .        Thus determination of the valving error, at the time of the occurrence, based upon a review of the          "
i      daily data was not possible.
i      daily data was not possible.
                                  ..- , _ _ .      ..
                                                        . , . -


_
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Page 3 Corrective Actions:
Page 3 Corrective Actions:
Upon discovery the root valves found almost closed were immediately fully opened , and the operability of the five other drywell pressure instruments was confirmed. Beginning on April 1, 1981, a program was initiated to check the position of all Unit 2 safety related instruments root valves. As of this date approximately 90" of these valves have been checked with no volving errors identified. In nddition, these valves are being tagged to identify them as safety related and prohibit operation without the approval of the Station Superintendent or his desi6nated representative.
Upon discovery the root valves found almost closed were immediately fully opened , and the operability of the five other drywell pressure instruments was confirmed. Beginning on April 1, 1981, a program was initiated to check the position of all Unit 2 safety related instruments root valves. As of this date approximately 90" of these valves have been checked with no volving errors identified. In nddition, these valves are being tagged to identify them as safety related and prohibit operation without the approval of the Station Superintendent or his desi6nated representative.
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Actions Taken To Prevent Reoc ur r enc e The listed corrective actions will prevent reoccurrnece.
Actions Taken To Prevent Reoc ur r enc e The listed corrective actions will prevent reoccurrnece.
Ver y truly yours ,
Ver y truly yours ,
                                                                        '
                                                     . J. ooney
                                                     . J. ooney
                                                     . erintendent Generation Division - Nuclear At ta c hm en t cc: Director, HRC - Of fice of Inspection and Enforcement Mr . Norman M. Haller, NRC - Office of Management &
                                                     . erintendent Generation Division - Nuclear At ta c hm en t cc: Director, HRC - Of fice of Inspection and Enforcement Mr . Norman M. Haller, NRC - Office of Management &
Program Analysis
Program Analysis P00R OP3 K
!-
                      -
P00R OP3 K
;
;
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Revision as of 02:04, 31 January 2020

Forwards LER 81-023/01T-0.Detailed Event Analysis Encl
ML19347E297
Person / Time
Site: Peach Bottom Constellation icon.png
Issue date: 04/15/1981
From: Cooney M
PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19347E298 List:
References
NUDOCS 8104240542
Download: ML19347E297 (3)
v • d • e


Text

_

'li Oj PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET .

1

._k . , N! P.O. BOX B699  %) ITI j-}~f3 g,)g PHILADELPHI A. PA.19101 [.'

azisi e4i-4ooo  ! '2 \

hoY [

q$ M l'

,y <e April 15, 1981 4 j ._. /

u l ., . -

l'r . Bo yca H. Grier, Director Of fice of Inspection and Enforcement Region I IIS !!uc lear Regulator y Commission 631 Park Avenue King of Prussia , PA 19406

SUBJECT:

LTCEllSEE EVENT REPORT NARRATIVE DESCRIPTION

Dear Pr. Grier:

The following was reported to Mr. C. Cowgill, Region I, Office of Inspection and Enforcement on April 1, 1981.

/

Reference:

Docket fio. 50-277 Report ?!o .: 2-81-23/1T Report Date: April 15, 1981 Occurrence Date: April 1, 1981 Facility: Peach Dottom Atomic Power Station RD #1, Delta, PA 17314 Technical Soecification

Reference:

Technical 9pecification 3.P.H. , requires that instr um e n t s

! listed in Table 3.2.B. be operable when the system (s) they initinte or control are required to be operable.

Description of the Ev ent l

l During investigation of anomalous indications on drywell pressure l

indicators , three of eight pressure transmitters were found with their root ( so ur c e) valves only partially open. The root valves l

l were immediately opened fully upon discovery and operability of the remaining 5 transmitter s was verified. The pressure l

transmitters involved are PT-2-10-100A, PT-2-10-100C, and PT-2 128.

f s

810 4 2 405VD-- 3 f f 0fhk

l Page 2 Probable Consequence of the Occurrence Investigation of the event determined that, all three instruments had been responding normr11y to drywell pressure fluctuations, indicating that the valves were not completely closed. In order to evaluate this possibility, the valves were re-closed to the approximate as found position and 1ccal leak rate tests were per formed at pressure from 0 to 9.7 PSID. Based upon extrapolation of these results to postulated accident conditions within the drywell, calculations were made of the response time of these instr um ents . The results indicate that the instruments would have provided a back up capability although not within the design time frame.

Sufficient drywell pressure instrumentation remained in service to provide the required RPS, PCIS, and ECCS initiation within system design requirements in normal fashion.

Cause of the Event:

Our investigation has not been able to determine the cause of the occurrence. Our administrative controls indicate that the valves should have been fully open. A review has been conducted of permits and maintenance request forms (MRF's) issued during 1980 and 1981 associated with changes in valving of the affected systems. No operations of any of these valves was indicated.

The three valves were verified open on 7/24/80 and 7/29/80 during the last Unit 2 Integrated Leak Rate Tests (ILRT).

The instruments involved are checked daily and the drywell pressures indicated by each are recorded on a surveillance log.

Plots made from these readings since the last ILRT have shown that the three affected instruments have responded normally to dr ywell pr essur e changes . Thus determination of the valving error, at the time of the occurrence, based upon a review of the "

i daily data was not possible.

Page 3 Corrective Actions:

Upon discovery the root valves found almost closed were immediately fully opened , and the operability of the five other drywell pressure instruments was confirmed. Beginning on April 1, 1981, a program was initiated to check the position of all Unit 2 safety related instruments root valves. As of this date approximately 90" of these valves have been checked with no volving errors identified. In nddition, these valves are being tagged to identify them as safety related and prohibit operation without the approval of the Station Superintendent or his desi6nated representative.

Further corrective actions will be described in a letter from Boyce H. Crier , Director , Region I, Office of Inspection and En forcem ent , United States Nuclear Ranulatory Commission, to Shields L. Daltroff, Vice President, Philadelphia Electric Com pan y.

Actions Taken To Prevent Reoc ur r enc e The listed corrective actions will prevent reoccurrnece.

Ver y truly yours ,

. J. ooney

. erintendent Generation Division - Nuclear At ta c hm en t cc: Director, HRC - Of fice of Inspection and Enforcement Mr . Norman M. Haller, NRC - Office of Management &

Program Analysis P00R OP3 K

-. . . -

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