ML20090M693

Forwards Results of Internal Insp of Shock Suppressors on Safety Related Sys Located Outside Primary Containment

ML20090M693
Person / Time
Site:	Monticello
Issue date:	02/25/1974
From:	Mayer L NORTHERN STATES POWER CO.
To:	Skovholt D US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 9105070410
Download: ML20090M693 (4)

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NORTHERN STATES POWER COMPANY Minneapolis, Minnesota 55401

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h February 25, 1974

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11 Mr. D. J. Skovholt D

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Assistant Director for Operating Reactor i IMR 1 DI4

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Directorate of Licensing O

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United States Atanic Energy Camrnission C1. i. M "" / 9/

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Dear Mr. Skovholt:

T'l/ TW N h0NTICELID NUCLEAR GENERATING PIAhT Docket No. 50-263 License No. DPR-22 Ilydraulic Shock Suppressors and Restraints Pursuant to our November 30, 1973, report, all shock suppressors on, safety rela'ed systems located outside primary containment have been inspepted exterm11y on a '.anthly basis. Rebuilding of these units, to provide ethylene prgylene internal parts and high tmperature, high pressure, leakproof oil fill fittings having Buna-N seats, has been ccupleted.

Additionally, all units located within primary containment were inspected externally on Febmary 17, 1974 Inspection results, corrective measures and other information requested in your letter to Mr. L 0 Mayer, dated October 1,1973, are contained in this report.

External inspection of the units in the drywell identified four units (SS-1BR, 4BR, 6AR and 8AR) which had indications of possible oil loss as observed by changes in the relative positions of the main piston rod and accumulator position indicator rod. No evidence of significant oil loss was found when the external portions of the units were examined.

None of the four units were inoperable. 011 was added to these units and no leakage was observed during the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

It is possible that the indicatioffs of oil loss were due to redistribution or leakage of air trapped in the suppressors during the initial oil filling operation.

External inspection of the units outside primary containment identified slight oil loss from two units prior to rebuilding, however, neither of the two units had sufficient oil loss to render the unit inoperabic. During the rebuilding program numerous units were found to have seal and metal parts damage due to the presence of foreign materials such as dirt, rust and metal chips. The"as-found" conditions of the rebuilt units are summarized in the attached Table I - Shock Suppressors Internal Inspection Results".

9105070410 740225 PDR ADOCK 05000263 P

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As noted in our Ictter of November 30, 1973, four units located within the drywell were provided thermocouples for determining the temperature environment. Additionally other units were provided temperature sensitive indicating tapes. Analysis of temperature daga over tge past several months indicates that the temperatures range frm 98 F to 140 F with an average g

tmperature of 115 F.

Yours very tnaly, Yhi i

L. O. Mayer, 'E Director of Nuclear Support Services Int /mmm

Attach, cc: JG Keppler G Charnoff Minnesota pollution Control Agency Attn:

E. A. Pryzina I

TABLE I - SHOCK SUFFRESSOR 1hTEPNAL INSPELTION RFSULTS Lhit Location Ihte of Last Maintenance As Found Condition Corrective Action

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SS-21 RIR Original Installation Scored (flinders and stuck Honed and polished cylinders.

piston rings.

Installed spare piston, rod, and rings.

SS-22 RHR Original Installation Scored cylinders, foreign Honed and polished cylinders.

material in accumulator, and back-up washer missirig.

SS-23 RIR Original Installation Found in good condition.

SS-24 RER Original Installation Found in good condition.

SS-25 RER Original Installation Found in good condition.

SS-26 RIR August 1973 Feund in good condition.

SS-27 RIR Original Installation Scored and pitted cylinder.

Replaced with new unit.

SS-28A RIE Original Installation Found in good condition.

SS-28B RER Original Installation Found in good condition.

SS-29 RIR O-iginal Installation Found in good condition.

SS-30 RIR Original Installation Found in good condition.

SS-31 RIR Original Installation Scored piston and cylinder.

Honed and polished cylinder.

SS-32A RIR Original Installation Found in good condition.

SS-32B RIR Original Installation Found in good condition.

SS-33 PJR Original Installation Scored piston and cylinder Honed and polished cylinder.

with a misaligned nose seal.

Realigned seal.

SS-34 RIR Original Installation Found in good condition.

SS-35 HPCI August, 1973 Found in good condition.

TABLE I - S110CK SUPPRESSOR INTERNAL INSPILTION RESULTS (Cont'd.)

l Unit location Date of Last Miintenance As Found Condition Corrective Action SS-36A IIPCI Original Installation Scored cylinder and dirty lioned and polished cylinder.

oil.

SS-36B HPCI August, 1973 Found in good condition.

SS-37 IIPCI Original Installation Scored cylinder and dirty 11oned and polished cylinder.

oil.

SS-38A RCIC Original Installation Scored cylinder.

lioned and polished cylinder.

SS-38B RCIC Original Installation Scored cylinder, piston loose Substituted a unit from a on shaft and dirty oil.

non-safety related system.

SS-40 IIPCI November, 1973 Not rebuilt since previously j

provided EP parts.

l SS-41 Core Spray November,1973 Not rebuilt since previously provided EP parts.

SS-42 HPCI Original Installation Found in good condition.

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AEC DIS' BUTION FOR PART 50 DOCKET MATP~

L, (TEMPORARY TORM)

CONTROL NO:_ 1647 FILE:

FROM:

DATE OF DOC DATE REC'D LTR MEMO RPT OTIER Northern States Power Co.

Minneapolis, Minn.

2-25-74 3-1-74 X

L. O. Mayer 70:

ORIG CC OTHER SENT AEC PDR XXX D. J. Skovholt 1 signed 39 CLASS UNCLASS PROP INFO INPUT NO CIS REC'D DOCKET NO:

40 50-263 xxx ENCLOSURES:

DESCRIPTION:

Ltr furn info re inspection of snubbers Table: Titled Shock Suppressor Internal Inspection Results trans the following....

DO NOT muuVE

.J.EKNOWLEDGE0 PLANT NAME: MONTICELLO (40 cvs attachment ree'd)

FOR ACTION / INFORM.fl0N 3-1-74 GMC BUTLER (L)

SCIMENCER(L)

ZIDIANN(L)

REGAN(E)

W/ Copies W/ Copies W/ 5 Copies W/ Copies CLARK (L)

STOLZ(L)

DICKER (E)

W/ Copies W/ Copies W/ Copies W/ Copies GOLLER(L)

VASSALLO(L)

KNIGHTON(E)

W/ Copies W/ Copies W/ Copies W/ Copies KNIEL(L)

SCHDiEL(L)

YOUNGBLOOD(E)

W/ Copies W/ Copies W/ Copies W/ Copies INTERNAL DISTRIBUTION kREGFILE TECH REVIEW DENTON A/T IND LIC ASST BRAI'IMAN

/AEC PDR dENDRIE GP,IMES OGC, ROOM P-506A JCHROEDER GAMMILL

/DIGGS(L)

SALTZMAN MUNTZING/ STAFF

1. MACCARY KASTNER GEARIN (L)

B. HURT fASE KNIGHT BALLARD GOULBOURNE (L) gg V GI AMBUSSO PAWLICKI SPANGLER LEE (L)

.CDONALD BOYD SHA0 MAIGRET (L)

DUBE v/ Input MOORE (L)(BWR)

STELLO ENVIRO SERVICE (L)

DEYOUNG(L)(PWR)

HOUSTON MULLER SHEPPARD (E)

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/SKOVHOLT (L)

NOVAK DICKER SMITH (L)

C. MILES P. COLLINS ROSS KNIGHTON TEETS (L)

B. KING DENISE IPPOLITO YOUNGBLOOD WADE (E)

EG OPR TEDESCO REGAN WILLIAMS (E)

FILE & REGION (3)

LONG PROJECT LDR WILSON (L)

MORRIS LAINAS S. REED (L)

STEELE BENAROYA HARLESS VOLIMER

/

EXTERNAL DISTRIBUTION M_

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(1)(2)(10)-NATIONAL LAB'S 1-PDR-SAN /LA/NY uTw 1 - DTIE(ABERNATHY) 1 - dSIC(BUCHANAN) 1-ASLBP(E/W Bldg,Rm 529) 1-GERALD LELLOUCIE 1 - ASLB(YORE /SAYRE/

1-W. PENNINGTON, Rm E-201 GT BR00KRAVEN NAT. LAB j

WOODARD/"H" ST.

1-CONSULTANT' S 1-AGMED ( Ru th Gu s s:an)

J16 - CYS ACRS AL%4 NEWMARK/BLUME/AGBABIAN EM-B-12 7. GT.

Sent te Lic Asst Diggs 3-1-74 1-GERALD ULRI KSON... ORNL 1-RD.. MULLER..F-309 GT