View source for PNO-V-89-021, on 890330,control Rod 5 Failed to Insert on Manual Scram Following Anomalous Reactivity Indications During Calibr.Caused by 2-inch Spacer Between Connecting Rod & Control Rod Not Included When Drive Assembly Changed

{{Adams
| number = ML20244C111
| issue date = 04/03/1989
| title = PNO-V-89-021:on 890330,control Rod 5 Failed to Insert on Manual Scram Following Anomalous Reactivity Indications During Calibr.Caused by 2-inch Spacer Between Connecting Rod & Control Rod Not Included When Drive Assembly Changed
| author name = Garcia E, North H
| author affiliation = NRC OFFICE OF INSPECTION &amp; ENFORCEMENT (IE REGION V)
| addressee name = 
| addressee affiliation = 
| docket = 05000163
| license number = 
| contact person = 
| document report number = PNO-V-89-021, PNO-V-89-21, NUDOCS 8904200052
| document type = PRELIMINARY NOTIFICATION OF EVENT OR OCCURRENCE (PNO,, TEXT-INSPECTION &amp; AUDIT &amp; I&amp;E CIRCULARS
| page count = 1
}}
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' PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PN0-V-89-21 Date: 04/3/89
  ;This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or
_public' interest significance. -The information presented is as-initially received without verification'or evaluation and is basically all that is known by Region V staff on this'date.-
FACILITY: General Atomicsu                                      Emergency Classification San Diego.: California                                Notification of Unusual Event:-
         -            Docket,No. 50-163'                                    Alert Site Area Emergency General Emergency X Not Applicable
                                          ~

==SUBJECT:==
CONTROL R00 FAILURE TO INSERT ON MANUAL SCRAMc On March 30, 1989, at 6:50 P.M. PST, the licensee initiated a manual scram of the TRIGA                            ,
1 Mark-F reactor.following anomalous-reactivity. indications during calibration'of control rod number 5'fo110 wing change ~out of the drive assembly. Control rod 5 failed to insert; The reactor operator gently twisted the connecting rod and the rod immediately inserted;
: Subsequent investigation by the licensee' determined that when the drive assembly had-been changed, a two inch spacer between the' connecting rod and the control portion of the rod-was.not included.
The Genera 1' Atomics TRIGA Mark F reactor is different from other IRIGAs in that it has five standard control rods and no transient ' control ' rod. The control portion of the rods are 13 inches long.instead of the standard 15. A two inch aluminum spacer
';batween the connecting rod and control portion is used to accommodate for the travel
, difference. ' This: spacer was missing-from the drive assembly.
LThe licensee has verified that the other four control rod assemblies have the. required spacer.' Other corrective actions include modifying the procedure for changing the
  . drive' assembly'to. include a step requiring verification that-the~ spacer is in. place and adding spacers to all spare connecting rods. The licensee, manufacturer of the
)TRIGAreactors,dcesnotbelievethatanyotherTRIGAhasthemodified13inchcontrol                                                       ,
' rods;with' spacers.
' This information is current .as of 8:30 A.M. PST, April 3,1989.
s
' CONTACT: Harry North (463-3762) or Emilio Garcia (FTS 463-3750)
                                                                                                         .          l DISTRIBUTION BY 5520:                        FAX T0:             .        .
l Date: 4-03-89                                     Date 4-03-89 Time-10:i5 AM l Chairman'Zech                EDO        RI        INP0                       ,
l Comm.. Roberts               AE0D       RII       NSAC
                                                                                                                          .V l Comm. Carr                   PA0        RIII      LICENSEE
                                                                                  -                                     =
Comm. Rogers            SLITP      RIV       RESIDENT INSPECTOR                                           ,4)M J
     ' Com. Curtiss            NRR                  HQS. OPERATIONS OFFILEn
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   -ACRS                       RES-                 D0T: (Trans. Only, Applicable State)
A              8904200052 890403
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