ML20149J449
| ML20149J449 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/02/1997 |
| From: | Gray K NRC |
| To: | |
| Shared Package | |
| ML20149J390 | List: |
| References | |
| FOIA-97-177 28335, NUDOCS 9707280221 | |
| Download: ML20149J449 (2) | |
Text
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EVENT FOLLOW-UP ASSIGNMENT SHEET No Sort Specifl M QUERY > " HUN" $ Assigned To & Event Number >= 28335 & Event Number <= 28335 ASSIGNMENT DATE: 02/06/95 ASSIGNED TO: HUNEMULLER N.
PLANT & UNIT: DRESDEN 3 EVENT DATE: 02/03/95 50.72 REPORT NO: 28335 DAILY REPORT DATE:
OTHER REPORT: #28336 PROJECTS CALL 2/6/95 EVENT DESCRIPTION TORUS TO REACTOR BUILDING VACUUM BREAKERS WERE DAMAGED DURING TESTING ON 01/06/95.
SPECIFIC FOLLOW-UP ASSIGNMENT DETERNINE DETAILS, EVALUATC SAFETY SIGNIFICANCE AND GENERIC IMPLICATIONS. IN ADDITION, ADDRESS THE FOLLOWING SPECIFIC CONCERNS: PROVIDE DETAILS CATHERED AT MORNING CALL, SEARCH FOR SIMIAR OCCURRENCES AT DRESDEN, AND CLOSE AS OTHER IF APPROPRIATE.
SAFETY SIGNIFICANCE: SIGEVENT AO OTHER OR ERIEFING: ;
1 EVENT FOLLOW-UP REPORTS INFORMAI4 CLOSEOUT DESCRIPTION CLOSE00T: The torus-to reactor building vacuum breakers, split body style swing check valves made by j Crane / Chapman, have a removable arm which may be used to operate the valve. Prior to manual operation, a flange i may be removed allowing the removable arm to be inserted into the hinge pin shaft. After cycling the check vstve disk, the arm is removed and the flange replaced and tightened down. This flange keeps leakage from tround the shaft 0-rings from leaking out. This flange is part of Primary Containment.
Prior to January 29, 1987, an LLRT was required to be performed following the quarterly vacuum breaker operability survuillance to ensure the flange was on tightly and there was no primary containment teakage.
Kowever, in 1987, an on-site review of a procedure revision to Dresden operating Surveittance (DOS) 1600-13, Suppression Chanber To Reactor Building Vacuum Breaker Operability Test For 2/3 1601- 31A&B, concluded the: Ce hinge pin shaf t flanges were not part of Primary Contelrunent and as such no LLRT was required as part of the j surveillance.
During a licensee's investigation into Torus to Reactor Building vacuum breaker LLRTs (February 1990) it was i concluded that the 1987 On-Site Review had been incorrect in their determination that the flange was not part of Primary containment. In addition, DOS 1600-13 did not contain adequate instructions to verify proper inst:llation of the flange. The investigation team reconsnended that the vacuum breakers access ports, which cllow access to the valve disk, should be used in the performance of the operability surveillance and that the cirresponding DOS procedure be revised, thus eliminating the need to remove the hinge pin shaf t flange (and the j subcequent required as left LLRT). This access port is outside of Primary Containment and allows for cycling of i the vacuum breaker valve disk with a broom handle. This procedure wes revised on October 22, 1993 but not until Operctions Department Personr:et had performed the survelltance (removed and replaced the flange, thus altering SUBMITTED BY: HUNEMULLER N. DATE: 02/13/95 APPROVED BY: R. DENNIG DATE: 02/16/95 CLO!EOUT NARRATIVE ENTERED: K. Gray DATE: 02/17/95 l
'I' # "* # # ##
9707280221 970722 PDR FDIA FDWLER97-177 PDR
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, f EVENT FOLLOW-UP ASSIGNMENT SHEET No Sort Specified QUERY > " HUN" $ Assigned To & Event Ntaber >= 28335 & Event Number <= 28335 CLOSEOUT DESCRIPTION (Continued)
Primary Containment without en as lef t LLRT) 11 times af ter the recomendation.
BJtween 1987 and 1992 the Unit 3 torus to reactor building relief check valves (3-160131A&B) hinge pins were removed and replaced per procedure on a quarterly basis without performing a local leak rate test of the flange upon conpletion of the surveillance. This was a Severity Level IV violation (50 249/94014-05(DRP)).
Th2 cvents described in 50.72 reports 28335 and 28336 were the result of a personnel error in that the auxiliary operetor performing the surveillance did not use the revised procedure. This resulted in a repeat of the vlotetton described in Inspection Report 50-249/94014.
- ! DENT:FY DISCREPANCIES FROM INITIAL EVENT INFORMATION: YES NO X N/A
- PERFORM RISK ASSESSMENT: YES NO X N/A ESTIMATE CONDITIONAL CORE DAMAGE PROBABILITY: YES NO N/A
- COMPARE WITH PREVIOUS SIMILAR EVENTS: X YES NO N/A PREVIOUS SIMILAR EVENTS: SIMILAR EVENTS AT DRESDEN SITE (SAME VALVES AFFECIED)
' RELATE TO ENFORCEMENT ACTIONS: YES NO X N/A
- RELATE TO US! GSI (NUREG 0933): YES NO X N/A RELEVANT U$l GSla PREPARE TO BRIEF: YES X NO
- TARGET CLOSEQUT SCHEDULE: 30 DAYS
- 1NITIAL SCREEMING PANEL EVENT / CONDITION SAFETY SIGNIFICANCE: X OTH E0! $1G A0
- REMAINING OR
- ADDITIONAL FOLLOW UP ITEMS:
- FINAL PANEL ASSESSMENT EVENT / CONDITION SAFETY
$1GNIFICANCE: OTH E0! SIG A0 *BMIS: RISK PROGRAMMATIC MARGIN N/A MENERIC FOLLOW-UP ACTION RECOMMENDED: YES NO PRIORITY (1,2,3,4) IN BUL GL f
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