DCL-85-195, Responds to Rev 1 to IE Bulletin 81-01 Re Insps of safety-related Snubbers.Insps Completed on 850426,per Temporary Procedure TD-8402, Visual Insp of Mechanical Snubbers, Included Stroking of All safety-related Snubbers
| ML20127D774 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 05/28/1985 |
| From: | Brand D PACIFIC GAS & ELECTRIC CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| CON-#385-286 DCL-85-195, IEB-81-01, IEB-81-1, OL, TAC-59760, NUDOCS 8506240331 | |
| Download: ML20127D774 (8) | |
Text
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MC PACIFIC OAS AND E LE C T RIC C O M PANY 1985 MAY 3i AH ll: 11!I IP G W1E i
77 DEALE STREET. SAN FRANCISCO, CALIFORNIA 94106. (415)781-4211. TWX 910 372 6587 REGt0N Vit.E D. A. B R A N D
$1"l17 May 28,1985 PGandE Letter No.: DCL-85-195 Mr. John B. Martin, Regional Administrator U. S. Nuclear Regulatory Commission, Region V 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368 Re: Docket No. 50-323, OL-DPR-81 Diablo Canyon Unit 2 Response to IE Bulletin 81-01, Surveillance of Mechanical Snubbers
Dear Mr. Martin:
Enclosed is PGandE's final report on inspections of safety-related snubbers at Diablo Canyon Unit 2 as required by IE Bulletin 81-01, Rev. 1, dated March 4,1981. This report completes the requirements of IE miletin 81-01 for Unit 2.
Approximately, 740 manhours were expended in review and preparation of this report and 2400 manhours were expended performing corrective actions (i.e.,
8506240331 850528 PDR ADOCK 05000323 O
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Mr. J. B. Martin PGandE Letter No. DCL-85-195 May 28, 1985 Page 2 snubber replacement and associated paperwork).
Kindly acknowledge receipt of this material on the enclosed copy of this letter and return it in the enclosed addressed envelope.
Subscribed to in San Francisco, California this 28th day of May 1985.
Respectfully submitted, Pacific Gas and Electric Company By u ) _..-)-
AL D'A. N d Robert Ohlbach Vice President Philip A. Crane, Jr.
Engineering Richard F. Locke Attorneys for Pacific Subscribed and sworn to before me Ga d Electric pa this 28th day of May 1985 E
, )L/ M PhilipjA. Grane, Jf.
Eancy J. Lemister, Wary Public in SEAL
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and for the City and County of San Francisco, State of California My comission expires April 14, 1986.
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G. W. Knighton 33,
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PGandE Letter No.: DCL-85-195 i
ENCLOSURE DIABLO CANYON UNIT 2 RESPONSE TO IE BULLETIN 81-01 Temporary Procedure TD-8402, " Visual Inspection of Mechanical Snubbers," was developed and implemented for Diablo Canyon Power Plant (DCPP) Unit 2 to comply with the requirements of IE Bulletin 81-01, " Surveillance of Mechanical Snubbers." Temporary Procedure TD-8402, which describes the visual examinations and tests performed on the snubbers, was forwarded for NRC Staff review with PGandE letter DCL-84-390, dated December 28, 1984.
The Unit 2 snubber inspection work began on February 14, 1985, and was completed on April 26, 1985. The inspection included stroking all of the safety-related mechanical snubbers in Unit 2.
Attachments 1 and 2 summarize all of the mechanical snubbers inspected.
Twenty-two snubbers were found to have impaired operability; these snubbers are identified in Attachment 3.
All 22 snubbers were replaced prior to fuel load, which began on May 7,1985. The results of the Unit 2 snubber inspections / stroking are individually documented for each snubber and filed in each snubber's equipment history jacket on file with the Maintenance Department at DCPP.
0335S/0033K
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ATTACHMENT 1 MECHANICAL SNUBBERS INSPECTED IN UNIT 2 Manufacturer & Supplier:
PACIFIC SCIENTIFIC COMPANY MODEL RATING QUANTITIES (LBS.)
PSA-1/4 (NF)*
350 23 PSA-1/4 (PRE-NF) 250 104 PSA-1/2 (N/F) 650 7
PSA-1/2 (PRE-NF) 500 46 PSA-1 (NF) 1,500 58 PSA-1 (PRE-NF) 1,000 14 PSA-3 (NF) 6,000 81 PSA-3 (PRE-NF) 3,000 29 PSA-10 (NF) 15,000 11 PSA-10 (PRE-NF) 10',000 32 PSA-35 (NF) 50,000 5
PSA-35 (PRE-NF) 50,000 3
PSA-100 (NF) 120,000 4
PSA-100 (PRE-NF) 100,000 1
418 TOTAL
- Nuclear Function 0335S/0033K
ATTACFMENT 2 MECHANICAL SNUBBERS INSPECTED IN UNIT 2 Manufacturer & Supplier: ANCHOR / DARLING INDUSTRIES MODEL RATING QUANTITIES (LBS.)
'AD-41 400 146 AD-71 700 72 AD-151 1,500 75 AD-501 5,000 101 AD-1601 16,000 54 AD-5501 55,000 41 AD-12501 125,000 14 503 TOTAL 0335S/0033K
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.ATTAC19fENT 3 SUfetARY OF SNUBBERS REPAIRED ITEN MFG-MODEL MODE OF FAILURE PROBABLE CAUSE OF FAILURE CORRECTIVE ACTION LOCATION 1
AD-501 Snubber will retract Probable cause not Snubber replaced.
412-153SL but not extend.
determined.
2 AD-151 Snubber strokes with no Snubber experienced a large Snubber replaced.
72-80SL resistance.
externally applied load.
3 AD-151 Snubber strokes with no Snubber experienced a large Snubber replaced.
71-24SL resistance, externally applied load.
l 4
AD-71 Snubber strokes with no Snubber experienced a large Snubber repisced.
71-64SL resistanco, externally applied load.
3 5
AD-41 Snubber will not stroke Probable cause not snubber replaced.78-361SL in last 1 inch.
determined.
l 6
AD-41 Snubber will not fully Probable cause not Snubber replaced.78-322SL extend.
deterinined.
7 AD-71 Snubber strokes with Snubber experienced a large Snubber replaced.
78-3893L no resistance.
externally applied load.
8 AD-71 Snubber strokes with Snubber experienced a large Snubber replaced.78-562SL no resistance.
externally applied load.
0335S/0033K ATTACIGIENT 3
SUMMARY
OF SNUBBERS REPAIRED ITEN MFG-MODEL MODE OF FAILURE PROBABLE CAUSE OF FAILURE CORRECTIVE ACTION LOCATION l
9 AD-71 Snubber will not stroke Probable cause not Snubber replaced.
75-8SL in last 1 inch.
determined.
10 AD-71 Snubber strokes with no Snubber experienced a large Snubber replaced.
413-540SL resistance.
externally applied load.
4 11 PSA-1/4 Snubber binds during Snubber experienced a large Snubber replaced.
70-30SL stroking.
externally applied load.
12 PSA-1/4 Snubber will not stroke.
Snubber experienced a large Snubber replaced.
70-21SL externally applied load.
13 PSA-1/4 Snubber barrel rotates.
Probable cause not Snubber replaced.
70-31SL determined.
14 PSA-1/4 Snubber will not stroke.
Snubber experienced a large Snubber replaced.
412-43SL externally applied load, i
15 PSA-10 Snubber will not stroke.
Snubber experienced a large
' Snubber replaced.
71-11SL externally applied load.
16 PSA-1/4 Snubber will not retract.
Snubber experienced a large Snubber replaced.
71-54SL externally applied load.
0335S/0033K --.
ATTACHMENT 3
SUMMARY
OF SNUBBERS REPAIRED ITEM MFG-MODEL MODE OF FAILURE PROBABLE CAUSE OF FAILURE CORRECTIVE ACTION LOCATION 17 PSA-1/4 Snubber will not retract.
Snubber experienced a large Snubber replaced.
78-76SL externally applied load.
18 PSA-1/2 Snubber missing barrel snap Probable cause not Snubber replaced.
75-4SL ring.
determined.
19 PSA-10 Snubber will not stroke.
Snubber experienced a large Snubber replaced.
73-2SL externally applied load.
20 PSA-1/%
Snubber will extend but Snubber experienced a large Snubber replaced.
78-1195L not retract.
externally applied load.
21 PSA-1/2 Snubber will not stroke.
Snubber experienced a large Snubber replaced.
413-545SL externally applied load.
22 PSA-3 Snubber has damaged spberical Probable cause not Snubber replaced.
74-33SL bearings.
determined.
0335S/0033K -