Text

Forwards Addl Info on Japanese BWR Recirculation Pump in Water Bearing Ring Problem.Related Info Encl
	ML20247Q899
Person / Time
Issue date:	02/06/1989
From:	Hauber R; NRC OFFICE OF GOVERNMENTAL & PUBLIC AFFAIRS (GPA)
To:	Denton, Murley, Stello; NRC OFFICE OF GOVERNMENTAL & PUBLIC AFFAIRS (GPA), Office of Nuclear Reactor Regulation, NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
Shared Package
ML20247Q883	List: IA-89-143, Responds to Request Re Recent Foreign Experience.Review of Several Data Bases Conducted.No Failures of Reactor Coolant Pump Impellers or Water Bearing Rings Due to Faulty Welds Found.Related Info Encl; ML20247Q878; ML20247Q899; ML20247Q909;
References
	FOIA-89-143 NUDOCS 8908070282
	Download: ML20247Q899 (19)
	v • d • e

_ _ _ _ _ _ _ ___ . .

%. L 196 TO: DISTRIBUTION FROM: R. Hauber, IP/GPA Ah

SUBJECT:

ADDITIONAL INFORMATION ON THE JAPANESE BWR RECIRCULATION PUMP IN-WATER BEARING RING PROBLEM Enclosed is additional information as follows:

1. Omoto to Burke telefax; ten pages/three subparts:

a. Comments on the Murley letter to GE

b. Revised account of the incidents

c. Responses to NRC questions at the Feb. 2 meeting

~. 4

2. Okubo (U.S. Embassy in Tokyo) to Burke telefax; three pages/two items:

a. Javan Times article, Feb. 4

b. Drawings -- Laycut of BWR components To m

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1 89080702B2 890728 PDR FOIA OKUTSUB9-143 PDR

4 Japan BWR Incident Distribution List Denton, GPA OCM Assistants:

Stello, EDO Dann-Lee, OCM/LZ Murley, NRR Lopez-Otin, OCM/TR Jordan, AEOD Burns, OCM/KC Shea, GPA/IP Scaroorough, OCM/KR Fouchard, GPA/PA Gray, OCM/JC Bradburne, GPA/CA Kammerer, GPA/SLITP w

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      -                                                                         Enclosure 1 DESCRIPTION OF DAMAGE OF BWR RECIRCULATION PUMP IN-WATER BEARING RING IN JAPANESE REACTORS tracking and failure of BWR recirculation pump in-water bearing ring was reported in two reactors (BWR-5) in Japan. The extent, severity, and safety implications rere assessed. It was concluded that there is no imediate safety concern for the domestic plants. However, we are folloufng closely the eyelopment of these events to ensure safe operation of comestic plants.

Description of Japanese Experience The staff has learned that damage of a recirculation pump in-water ring was icentified at Tokyo Electric Power's Fukushima-Daini Unit 1 during annual maintenance last year. The same incident was reported at the same unit in 1984 The damage was repaired but it occurred again in 1958 and was fixed at that time. The most recent problem was fcund at Fukushima-Daint Unit 3 in

  . January 1989. They are both EWR-5 plants.

In January 1989, vibration of the primary Icep recirculation (P ) pump was cbserved during operation. The 11 ant was shut c'own for inspec ion. It was found that the bearingying was arcken into tnree pieces ce .arce pieees& many small pieces). ore piece was sticting on the upper 1cceller; another ofece est found insice the reactor vessel; anci the thire piece became a loese part but M cas fi n lly recovereo. The PLR pump in Fukushima.Daini Unit I was manufactured by Byron. Jackson Co., but 4he Unit 3 pump was made by EBARA Co., a Japanese manufacturer. MITI efficials feel that the cracks were due to high stresses of the comoonent ifinned by__ .e -@# M Uaterflow. They consicer that snis problem coes nat depend on'bR tvoer-ivrn'iiusp * '7 suppiters, but it might occur at any plants which used the same wit 6TW i technicue la fillet weid .lotntng a statnless steel bearing). ) Roa& 0 74 t " * 'W & Am"*y

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.vanese Experience trned that damage of a recirculation pump in-water ring was i syo Electric Power's Fukushima-Daini Unit 1 during annual 1 year. The same incident was reported at the same unit in
!a aostwas repaired recent but itwas problem occurred again found at in 1988 Daini Fukushima and was Unitfixed 3 in at tey are both BWR-S plants. vibration of the primary loop recirculation (P ) pump was /' O operation. The plant was shut down for inspec ton. It was d eating ring was broken into three pieces (a targe pieces. and ; s). One piece was : ticking on the upper impeller; another piece Fthe reactor vessel; and tne third (iice became a loose part out / @ l vereo. Flukushime-Dair6 Unit I was manufactttrat.by Byron-Jackson Co., but was made< by ERAREco_ , a Japanesg gur33fgCturer. MITI official!L .4,'@ icks were due to high stresses of the component induced by y consider that tnts problem does not deoend on BWR tyoes and cumo p - t might occur at any plants whien u!ied tne same weldine et weld Joining a stainless steel bearing). A.e. p ear b w s i d o w + w 2 m e .a. a r y . y a few rad a mtzJtic.y
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EMBASSY OF THE-UNITED STATES OF AMERI
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TOKY0. JAPAN e +++++++ : : : : : : : : : : : : : : : : : : : : : : : :+++
++++. : : : : : : : : : : : : : : : : : : : : : : -
DOE-TOKYO - FACSIMILE MESSAGE I Ib' Date:
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301-492-0260 Time: (JST) Telefaxw.Ho.
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NRC/0IP Tm Attention: % v ,,4 ,. n i ,,.6, ns? m w.:.;;;;; .; ; :.;;;.; ;;******M m.
********************+**;;;;;;;;;;;;;; ;;..;;; ;...;;p; From:
L aubo 7 3.f,x no, [03) 582-0496
v. s. Department of Energy American Embassy Tel. No. (03) 224-5478 il l
10-5, Akasaka 1-chome (DOESecretary) i Chiyoda-ku, Tokyo 100 Japan l
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7p a.,; 1. g ' Number of Pages Ti*i Sentby:)
~~'- 'S mi' (Initial (ExcludingCoverSheet) = =:.np
Subject:
TEPCO Fukushima II-3 INCIDENT W'
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Remarks: m 4 O e e e
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) ~2 ' THE JAPAN TIMES e SATURDAY, FEBRUARY 4,1989' j \ .- , . ~. . ~ . -Broken partin water pump ' l endangered nuclear reactor ~
g FUKU' 5 mMA (Kyodo) A broke'n ered at Reactor No. 3 of the ' If the washen, wm Ecked part found in the' cooling com inside the reactor,they might pump of a nuclear reactor Nuclpany's car PowerNo. 2 Fukushima - Plant, harm the surfaces of fuel here could have led to a se- rods, causing Icaks of' As these am the f rious accident,it was learned Iems of their kind m,irst Japan,prob.radioact e material into Friday. . . the company immediately de cooli ..- ter, it was re-
~ . The problem was located in cided to halt the o?cration of Tut ra'di5 tion levels'in the Reactor No. I at ;ts Kariwa reactor did not show any sign -
the pump coolinke. of t 1.1 water recycling million kilo- Nuc! car Power Plant in watt boiling light water Kashiwazaki,Niigata Prefec- ng th t eie 's d reactor of a power plant- ture, today to conduct checks not suffer such damage, a 1 About one'.fifth of a dough. of thesame type of pump used prefectural government offi- , nut shaped metal plate 2n that reactor, the spokes- cial repoded. ! cttached us an axle in the man said. . The four missing washers oump was torn off, the Tokyo Takash! Usami, head of the : 51ectric Power Co. said. No. 2 Fukushima Plant, visit. are believed to be inside a jet l The plate,with a majoraxis ed the Fukushima prefectural jump,p titivice to send cool-cf 1 meter, weighs about 300 government Friday afternoon ng wscr back to the reactor, kg and the torn off part about and expressed regret for hav. the com,pany spokesman said. !' 20 kg, it was reported. - ing caused the treubles. This is because the exit of
- The com any found the .the pum is 33 mm in dia-The broken metal plate also problems furing a safety metern ch means it is too damaged another part inside check that began Jan. 6. On small to:-eflow the washers the pump. Moreover, eight that day, the company sus. Into the reactor,be explained. ~
bolts, each about 8 cm long, The company is now using d five washers, each with a onimmediate! hended the reactor's afteritmon. opera.fiberscopes to search for the thfe ss of 2 mm, botfi it red abnormafvibrations of' washers, he added. " the axle of the pump, the According to nuclear ex-used to attach the plate to the spokesman said. ,perts, the cooling water re-cxle,' had come off, the com-pany said. - . All e!ght of the bolts and one . cycling pump plays an impor . washer were recovered, but tant part an controlling the According to a spokesman, four washers are still mis ' volume of cooling water that these problems were discov- sing, he said. ~ flows into the reactor. .
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Purpose:
of weld f ailures in Byron-Jackson' primary loop recirculation pump and another pump designed similarly. It is e pected that recipients will review the information for applicability to their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in ! this information notice do not constitute llRC requirements; therefore, no ' specific action or written response is required. ; Description of Otrcumstances ;, .i , i The information received by the flRC staff is related to boiling water o-A> ~ 1 reactors; however, the nature of the failures were such as to potentially & affect all pumps of similar_. des.i_gn 'The events brought to the staff's attention are as~follows: (a) In 1984, a foreign BWR experienced a failure in the attachment weld of a ring which surrounds the bearing housing component of a foreign '= pumpGiry.similar to Byron-Jackson recirculatioripump. The operator - - % '> - 3 W- ., . 4 : performed repairs involv'ing fillet welds a plied at the crack loca-(tions.-DurJnq inspections last year (1988 cracks were found at the , p - ,, (same locatfor.s. The repair involved applyJng butt--welds-at-the4 racks f,,j f.i, 'i locations. ' (b) Similar problems were recently repo ted at another BWR plant. Signi-ficant vibration was observed durin.g operationL The plant was imediately shut down for inspection. It was found that the welds ' had failed entirely and that the ring had broken into three pieces;s\ ',q 7'. ^ two of the pieces were relatively large and one of them was broken '. up into smaller pieces. One )iece jappeared to be attached to the l " ' ') upper impeller and one piece .1ad travelled into the reactor vessel. ,/ ,. . . i . i . .. i (' n... .r .: E ,% . l "' *b \ g % ' E C I- . . . , , 6 4 $ d. '< g . 4r ..: -. 4 -. L _ In . _ _ _ _ - - _ - _ _}}

ML20247Q899

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ML20247Q899

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