ML19263C329

LER 77-105/03L-1 on 771011:during 18-month Surveillance testing,13 Hydraulic Snubbers Appeared to Have Suspect Lockup & Bleed Rate Valves.All Snubbers Have Been Rebuilt & Tested to New Generic Values

ML19263C329
Person / Time
Site:	Beaver Valley
Issue date:	02/13/1979
From:	Werling J DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19263C328	List: ML19263C327 ML19263C329
References
LER-77-105-03L, LER-77-105-3L, NUDOCS 7902210261
Download: ML19263C329 (2)

Text

Update Report U.S. NUCLEAR REGULATORY COMMISSION NRC FORM 3G6 (7 771 - Previous Report Date 11/10/77 LICENSEE EVENT REPORT CONTROL BLOCK: l l l l l l l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) i 6 l0 l1l8 9l P l LICENSEE 7

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EVENT DESCRIPTION AND PROBASLE CON 3EQUENCES h O 2 l During performance of 18-month surveillance testing of 13 hydraulic snubbers, the l 10 l 3 l l snubbers appeared to have lock-up and biced rate values which were suspect. Based l o 4 I upon subsequently established acceptance criteria, all snubbers in Table 3.7-4 of l o s l Tech Spec 3.7.8.12 have been rebuilt and tested to the criteria. The seals of all l Lo 16 I I TTT Grinnell snubbers requirea for safe operation of the pinne hnve been chanced I o 7ll to ethylene propylene material. I I

o 8 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUDCODE l 0j_j 7 8 l x l x l@ Lx_J@ LLJ O la l A l N l G l E l R lh l Z lh20 W h 9 10 11 12 13 18 19 SEOUE NTI AL OCCURRENCE REPORT REVISION REPORT NO. CODE TYPE NO.

LER/RO hvENTYEAR

@ yUQERE RT l7l7 l-l l1 l0 l 5 l l/] l0l3l lL l l-l l 1l 21 22 23 24 26 27 28 29 30 01 32 KEN ACT ON ON PL NT ET HOURS S B 1 D F OR L4 B. SUPPL E MAP FACT RER lFl@lZl@ l Zl@

33 34 33 lZ 36 l@ l0l0l0l0l 31 40 lYl@

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42 lA 43 l@ 44 Il 2l 0l 7l@ 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h i o l When the snubbers were purchased, no lock-up and bleed rate was specified. The l li 13 i i standard setting was nominally 4 in./ min. lock-up and 0.1 in./ min. bleed after I i, ;7l l lock-up. Generic values have now been developed which specify a nominal lock-up ]

5 l i l 31 ] of 8 in. / min. and 4 in./ min bleed after lock-un. The snubbers have been rebuilt l l

i 4 l and tested to these new ceneric values. 80 7 8 9

' STA  % POWER OTHEp STATUS OtSCO RY DISCOVERY DESCR' ' TION R l Gl@ l 0l 0l 0l@l N/A l lBl@l Surveillance testinn l A TIVITY CO TENT AMOUNT OF ACTIVITY LOcATI ; , OF RE LEAS E MLEASEO OF RELE ASE 1 6 N/A l N/A l 7 8 9 Zl @ l 10Zl@ lt1 44 45 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION i 7 l0l0l0l@lZl@l N/A l PERSONNE L INJURIES NUMBER DESCniPTION ITTa1 10 l 010 l@l12 N/A l go 7 8 9 11 LOSS OF OR DAMAGE To FACILITY Q TYPE DE SCRIPTicN N/

Q ]Zl@l 7 8 9 10 N/A 80 l

7902210A6/

2 o iSSuf lN f@l llCRiPTiO~@ N/A l l l l 1 1 l l l l l l l l :;

7 8 9 to 68 69 80 5 J. A. k'erlinR PHONE:

412-643-1258 E NAME OF PREPARER o s _

Attachment to Updated LER 77-105/03L Echver Valley Power Station Duquesne Light Ccmpany Docket No. 50-334 A review has determined that the worst case post-lockup thermal transient which could be experienced by a QA Category I pipe and associated snubber would be the inadvertent auxiliary spray through the pressurizer auxiliary spray line. This transient would occur when the auxiliary spray line injected 100"F water into the 4 inch pressurizer normal spray line that was initially at 547"F. The resultant maximum thermal growth rate at the location of the Category I snubber was calculated to be 1.36 inches per minute. Since the actual bleed rate setting on test was set to be greater than or equal to 2 inches per minate, the thermal growth of the piping during lock-up can be accomodated.