ML20027A369

From kanterella
Jump to navigation Jump to search
LER 78-034/03L-1:on 780326,absolute Position Indication for Group 5,Rod 12,declared Inoperable.Caused by Component Failure in Penetration Area.Containment Conductors Connected to Spare Penetration Connectors.No Further Problems
ML20027A369
Person / Time
Site: Davis Besse Cleveland Electric icon.png
Issue date: 04/21/1978
From: Kovach S
TOLEDO EDISON CO.
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20027A363 List:
References
LER-78-034-03L, LER-78-34-3L, NP-33-78-38, NUDOCS 7811210362
Download: ML20027A369 (3)
v • d • e


Text

U. S. NUCLEAR REGULATORY COMMISSION NRC FORM MG W.77)

LICENSEE EVENT REPORT CONTRoLsLoCo l l l l l 1 (PLE ASE PRINT OR TYPE ALL REQUtRED INFORMATIONI lJg l011l l 0l Hl Dl Bl Sl lgl50l0l-l0l0lNjPjFl-[0j3lgl4l1l1(1[ljgl 1 & 3 LICENSEE CoJE 14  : L:Ci'.SE NuvSER .' $ ;6 uCENSE TYPE JJ 67 GT bd CON'T lolil L'y l L l@l 0l 5 l 0 l - l 0 l 3 l 4 l 6 , 0l3l2l6l7l8 g 0l4}2l1l7}8Jg 74 75 AE'CRT cATE 8J 64 63 EVENT oATE i 8 60 61 COCKET *.UVSER EVENT DESCRIPTION AND PROBA8LE CONSECUENCES hto for Control Rod 12 of Group 5 was de Io l2l l The Absolute Position Indication (API)

The API for Control y l o t a l I operable on 3/26/78 at 0040 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> and on 3/31/78 at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />.

Rod 11 of Group 5 was declared inoperable on 4/3/78 at 1549 hours0.0179 days <br />0.43 hours <br />0.00256 weeks <br />5.893945e-4 months <br />. These occurrences ;

Io IdI l There y g n ,3 f g placed the unit in Action State =ent (a) of Technical Specification 3.1.3.3.

The Relative ,

l o is t I was no danger to the health and saf ety of the public or unit personnel.

1 l3l7; l Position Indication (RPI) as well as zone reference indication f or each rod were operap (NP-33-78-38) g , g-} ; ble during the period that each API was inoperable.

CAUSE CovP. VALV E SYSTE\1 CAUSE SUFOCE SU8M OE CODE Coci SUBCOOE COVPANENT CODE loisi S

i Rl Bl@ lE l@ l A l@ lf3El Ll El Cl 0l Nl@ l Z l@ l Z l @ Revision 10 11 12 14 19 20 7 a CCtuRRENCE PEPCRT SEovENTIAL ' sw).

A PoRTNo COO 5

,_EVENTY AR 3 LER ao 31 IM i 1 I l'YPEI l-l 111

@ af.:.j,a; 1 7I I l-l i 1 26 1

27 23 23 30 31 J2 22 23 24

_ 21 FoR1 9. 5P ' MAN FAC b ER TAK O oN FL NT TO woVRS 22 SB t

{ B_JQl Zl@ lZl@ lZl@

6 l0IOl0l 31 l

40 l41 Y l@ l42Y l@ lA 43 l@ l44B l 3 l 6 l 547l@

34 33 1

CAUSE CE$CRIPTION AND CORRECTI'/ E ACrlONS h ion areaJ j , ; o l lThe cause of the occurrence is attributed to ccmponent failure in the cenetrat l,

[

[,,,j j During the May/ June / July 1978 outage, the conductors which carry the Group 5, Rod 12 to the control rod drive cabir.ets were connected to spare; mg API signals from conta2 sent connectors of the penetration. Post-outage operation has revealed no further problemsp g,,,,l I

i Iil: i I 60 7 8 9 btSCO RY DISCOVERY CESCRIPTioN ST L 'i po?;ER oTHER $TA TU3 '

l 11 I5) [EJg l 0l 8l 4gl NA l [ A [gl NA l ACTtvity CO TENT LOCATION oF RELEASE aftErsE AUouNT CF ACTivsTY I

)

lt is l l Z j @s Cr aELE A3Eb h NA l l NA s kE

'$. Tv E o NA

@ l l 1 l 7 l l 0 l 0 l 0 lhl Z lhl

ESCaiPrioN *

,ERSe.sELiN;ULS Neveta CES: R Prion @ 7 811210 hv'1 I linilolol0I@lNA 7 8 9 11 12 ao

(

T #E Es #T ON l N^

l ' h l4 L, Z J@lm 1 NRC USt ONLY i:s.E N Es:=.P m N h l ll t1illIII I1 l}

I ' I C I I N lhl NA ea sa c.;

1  % ) TO "O

Susan p..,,.5, PHONE: @ S U W" - " -

DVR 7S-049, , A..e cF PREPARER

TOLEDO EDISON COMPANY DAVIS-BESSE UNIT ONE NUCLEAR POWER STATION SUPPLEMENTAL INFORMATION FOR LER NP-33-78-38 DATE OF EVENT: March 26, 1978 - April 3, 1978 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Absolute Position Indication (API) for Group 5, ,

Rods 11 and 12 was inoperable.

Conditions Prior to Occurrence: The unit was in Modes 1, 2 or 3 with Power (MWT) ranging from 0-2336, and Load (MWE) ranging from 0-394.

Descrintion of Occurrence: On March 26, 1978, the API for Rod 12 of Group 5 was observed to have had sporadic indication. At 0040 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br />, this Absolute Position Indication was declared inoperable by the Shif t Foreman. On March 31, 1978, at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, the same API was declared inoperable. On April 3, 1978 at 1549 hours0.0179 days <br />0.43 hours <br />0.00256 weeks <br />5.893945e-4 months <br />, the API for Group 5, Rod 11 (displayed on Group 5, Rod 12's position indicating meter) was declared inoperable.

These occurrences placed the unit in Action Statement (a) of Technical Specifica-tion 3.1.3.3. This Technical Specification requires the operability of all APIS in Modes 1 and 2. Action Statement (a) of Technical Specification 3.1.3.3 speci-fies that operation may continue provided that the position reference indicator (zone reference) of the control rod is verified within eight hours of the occur-rence, and at least once per twelve hours thereafter.

In each case, Group 5 was placed in the asymmetric bypass condition. l Designation of Apparent Cause of Occurrence: The cause of the occurrence is attri-buted to component f ailure in the penetration area. The exact cause of the occur-rence was not determined until entry into containment was permitted during the 1 May/ June / July,1978 outage.

Ansivsis of Occurrence: There was no danger to the health and safety of the public or to unit personnel. The Relative Position Indication (RPI) as well as zone reference indication for each rod was operable during the period that each API was inoperable.

Corrective Action: Surveillance require =ents 4.1.3.3 as well as the require =ents of Action Statement (a) was followed.

As reported in Licensee Event Report NP-33-78-26, Maintenance personnel perfor=ed an inspection of connectors and cable at the bulkhead, control rod drive mechanism, and position indicator tube for Control Rod Drive Group 5 Rod 12 under Maintenance Work Order (MWO)78-319. Since Licensee Event Report NP-33-78-26 was written, LER #78-034

m t

l TOLEDO EDISON COMPANY DAVIS-BESSE UNIT ONE NUCLEAR POWER STATION PAGE 2 SUPPLEMENTAL INFORMATION FOR LER NP-33-78-38 Maintenance has replaced the cable from the API tube to the bulkhead (MWO 78-512).

MWO 718-78 was issued (af ter approval of Facility Change Request 78-169) to change wires at the penetration from Rod 12 to a spare and to switch the position indication cables for Rods 11 and 12 at the position indication tubes. The posi- On tion indication patch for Rods 11 and 12 were exchanged under MWO IC 277-78.

March 30, 1978, the patch and position cables were returned to their original con-figuration.

On March 31, 1978, under Facility Change Request (FCR)78-173, the position indi-cation cable for Group 5 Rod 12 was switched with the position indication cable for Group 5 Rod 11. In addition, the cable for Group All work 5 Rod 12 from the penetration was performed under MWO to the bulkhead was replaced with a new one.78-512. This change was recommended by Diacond Power Specialty Corporation as an aid in troubleshooting the Group 5 Rod 12 problem. As a result of this change, the API signal for Group 5, Rod 12 was on Group 5 Rod lls API meter and vice versa.

The zone reference Relative Position Indication for each rod remained unaffected.

lights for Group 5 Rod 12 were displayed on Group 5 Rod lls zone reference lights, and vice versa.

On April 7, 1978 under FCR 78-180 and MWO IC ,285-78, the API signal leads for Group 5 Rod 11 were exchanged with the API signal leads for Group 5 Rod 12 at the penetration. The APIS for both Rod 11 and 12 of Group 5 were inoperable for the few minutes required to switch cables. RPIs and zone reference lights for each rod were operable during this time. The API signals for Group 5 Rods 11 and 12 were returned to their respective meters. The zonezone reference lights for Rod 12 reference l'ights. As a of Group 5 were still displayed on Rod 11 Group 5 result of this change, it was determined that the problem with the API on Rod 12 of Group 5 originated in the penetration area.

The unit was removed from Action Statement (a) of Technical Specification 3.1.3.3 on March 30, 1978 at 1750 hours0.0203 days <br />0.486 hours <br />0.00289 weeks <br />6.65875e-4 months <br />, on March 31, 1978 at 1845 hours0.0214 days <br />0.513 hours <br />0.00305 weeks <br />7.020225e-4 months <br /> and on April 6, 1978 at 0950 hours0.011 days <br />0.264 hours <br />0.00157 weeks <br />3.61475e-4 months <br />, after performance of Surveillance Test ST 5013.03, "Contain-ment Pressure to SFAS Channel Calibration".

During the May/ June / July outage, position indication cables for Group 5, Rods 11 and 12 were returned to their original rods. Also during this time under Mainten-ance Uork Order 78-512, the conductors which carry the Group 5, Rod 12 API signals 1 from containment to the Control Rod Drive Cabinets were connected to spare connec-tors of the penetration. Post-outage operation to date has revealed no further problems. A recurrence is not expected since it is felt that the difficulties in the problem area (penetration) have been resolved.

The API for Rod 12, Group 5 was Failure Data:_ This is a repetitive occurrence. 1 inoperable in three previously reported occurrences, Licensee Event Reports NP-33-78-02, NP-33-78-19 and NP-33-78-26.

LER #78-034

Retrieved from "https://kanterella.com/w/index.php?title=ML20027A369&oldid=2495571"