ML19289F305

LER 79-057/01T-0 on 790518:hydraulic Snubbers May Not Have Fulfilled Their Functional Requirements.Cause Under Investigation,But Possibly from Improper Installation of Snubbers During Const

ML19289F305
Person / Time
Site:	Davis Besse
Issue date:	05/30/1979
From:	Oneill J TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19289F303	List: ML19289F302 ML19289F305
References
LER-79-057-01T, LER-79-57-1T, NUDOCS 7906070208
Download: ML19289F305 (3)

Text

NRC F ORM 366 U. S. NUCLE AR REGUL ATORY COMMISSION (7 77)

LICENSEE EVENT REPORT CONTROL BLOCK:

1 l l l l l lh 6

(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) l o l 18 l9 l 0 l 11 7

l D l B [ S l 141 l@l 0 l 0 l - l 0 l LICENSE 0 l N lNvYBEHP F l-- l 0 l 321l@l264 l1 1l1l1l@l l l@

LICENSEE CODE 15 LICEP.SE TYPE JO bl CA T $8 CON'T l0l11 S$n'C$ I L hl610 l 5 l 0DOCKET l - 10 3 l 4 l 6 @l 01511 l8 7l9l@l015l3l0l7l98J @

7 8 60 NUV8E R 03 03 EVENT O TE 14 15 REPORT DATE EVENT DESCRIPTION AND PPOBABLE CONSEQUENCES h o 2 l It was determined a reportable event existed in that some hydraulic snubbers may not o 3 lhcVe filfilled their functional requirements. There was no danger to the health and  ;

l o l 41 [ saf ety of the public or station personnel. No seismic event was experienced during l 0 s Ithis period. (NP-32-79-07) l l o 16 I l I lo 7 [ l

[O 8 l l 7 8 9 :80 SYSTEM CAUSE CAU"E COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SU8 CODE SUSCODE 7

o 9 8 lX IX lh WQ lC l@ l Sl Ul Pl Ol Rl Tlh WQ l Zl@

9 10 11 12 13 18 19 20 SEQUE N TI AL OCCURRENCE REPORT REVIStoN

_ EVENT YEAR REPOR T NO. CODE TYPE NO.

a

@ lLER Uqt; RO 17 19 I l-l 10 15 l 7 i l-l i 0l 11 l Tl -

l 0l

_ 21 22 2J 24 26 21 28 29 30 31 32 TAKEN ACTC ON PLANT TH HOURS S B I FO R. .B. SU PLIE MA C TURER l B l@74 Xl@ W@

33 33

[ Z__j@

36 l0l0l0l0l 31 40 lY 41 l@ lY 42 l@ 43 Al@ lI l2 l0 l7 [@

44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i O l Although the cause of this occurrence is still under investigation, the cause could  ;

i i l have been improper installation of the snubbers during construction. Toledo Edison I i 7 l personnel and representatives of ITT Grinnell are working gether to determine the

,i 3 l cause of these problems, correct them, and determine what is necessary to prevent l

i 4 l further similar occurrences. l 7 8 9 FJ STA S *.POWER OTHER STATUS blSCO RY DISCOVERY DEssmpTION i 5 l Gl@ l 0 l 0 l 0 l@l NA l l B lgl Surveillance Test ST 5044.01 l AC flVI TY CO TENT RELEASED OF RELE ASE AMOUNT OF ACTIVITY LOCATION OF RELE ASE 1 6 8 9

@ lZl to l NA 11 44 l l NA 45 l

PERSONNEL EXPOSURES EJ NUVBER TYPE D E SC RIPTION i 7 1 01 0l Ol@lz l@l NA I PERSONNEL INJU tES NUVREH OESCRIP TION i R I 0101 Ol@l NA 8 9 11 12 80 LOSS OF OR DAMAGE TO FACILITY O l

\/

i 9 TYPE

] @l DESCRIPTION NA 7906070aq I 8 9 10 80 t ISSUE

• 2 O 8 9 hl DESCRIPTION NA l lllllll[lllll$ l 10 68 69 80 ; l VR 79-074 NAME OF PREPARER 419-259-5000. E-t.

PHONE: 252 2, 4

IOLEDO EDISON COMPANY DAVIS-bt,5SE NUCLEAR POWET- c~'ATION UNIT ONE SUPPLEMENTAS INFORMAiIC a 'I NP-32-79-07 DATE OF EVENT: May 18. 1979 FACILITY: Davis-Besse Unit 1 1DENTIFICATION OF OCCURRENCE: Hydraulic snubbers deficiency Conditions Prior to Occurrence: The unit was in Mode 5, with Power (MWT) = 0, and Load (Gross MWE) = 0.

Description of Occurrence: At 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> on May 18, 1979, it was determined a repor-table event existed in that some hydraulic snubbers may not have fulfilled their functional requirements.

Plant snubbers, nulcear safety related with a capacity of less than 50,000 pounds, are in the process of being tested per Surveillance Test ST 5044.01, " Inspection of Safety Related Snubbers", which removes each snubber from its field location and tests the snubber on a test stand.

The ~following is a list of some of the deficiencies now known to exist:

(A) Some snubbers had fittings installed which may not have providad seal, and may have permitted air in-leakage to degrade snubber performance.

(B) Flitid reservoirs were installed on some snubbers with orientations which may not have allowed the reservoir to perform properly and/or allowed air in-lea kage .

(C) Installation of brackets mounting the local reservoirs for three snubbers were not per design and required removal of cap head body bolts which could have allowed air into ute hydraulic cylinders and possibly disturbed the o-ring seals.

(D) Two snubbers had non-ethylene-propylene gasket material.

Of the first 133 snubbers tested, 78 did not meet all the acceptance criteria.

This report is being submitted in accordance with Technical Specification 6.9.1.8.f.

Designation of Apparent Carse of Occurrence: Although the cause of this occurrence is still under investigation, the cause of the deficiencies could have been improper installation of the snubbers during construction.

LER #79-057

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE i' AGE 2 SUPPLEMENTAL INFORMATION FOR LER NP-32-79-07 Analysis of Occurrence: There was no danger to the health and safety of the public or to station personnel. No seismic event was experienced during the period.

Corrective Action: Under Maintenance Uork Order 79-2009, and as per Surveillance Test ST 5044.01, safety related snubbers with capacity of less than 50,000 pounds are being tested and returned to original specifications.

The cause of the problems and -corrective actions are still being evaluated.

Toledo Edison personnel and representatives of ITT Grinnell are working together to determine the cause of these problems, correct them, and determine what is neces-sary to prevent further similar occurrences. Further information will be provided i

by a supplement to this report.

Failure Data: There have beca no previously reported similar occurrences.

LER #79-057 2233 0.39

.