ML19323A025
| ML19323A025 | |
| Person / Time | |
|---|---|
| Site: | Shoreham File:Long Island Lighting Company icon.png |
| Issue date: | 04/04/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Wofford A LONG ISLAND LIGHTING CO. |
| References | |
| NUDOCS 8004110053 | |
| Download: ML19323A025 (1) | |
Text
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NUCLEAR REGULATORY COMMISSION o
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REGION I S
631 PARK AVENUE 4, * * * = *,&,&
KING oF PRUSSIA, PENNSYLVANIA 194M Docket No. 50-322 April 4,1980 Long Island Lighting Company ATTN:
Mr. Andrew W. Wofford i
Vice President 175 East Old Country Road Hicksville, New York 11801 L
Gentlemen:
The enclosed IE Bulletin No. 80-07, " SWR Jet Pump Assembly Failure," is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
l Sincerely, AH W
Boyce H. Grier
" Director
Enclosures:
1.
IE Bulletin No. 80-07 with Attachments 2.
List of Recently Issued IE Bulletins CCNTACT:
D. L. Caphton (215-337-5254) l cc w/encls:
J. P. Novarro, Project Manager Edward M. Barrett, Esquire Edward J. Walsh, Esquire T. F. Gerecke, Manager, Engineering QA Department i
8 0 04ti o g Q
4 SSINS No.:
6820 Accession No.:
UNITED STATES 8002280648 NUCLEAR REGULATORY COMMISSION l
OFFICE OF INSPECTION AND ENFORCEMENT
~
WASHINGTON, D.C.
20555 i
IE Bulletin No. 80-07 Date: April 4, 1980 Page 1 of 4 i
BWR JET PUMP ASSEMBLY FAILURE l
Description of Circumstances:
On February 2, 1980, Commonwealth Edison Company (CECO) reported that a jet pump failed in Dresden Unit 3 while operating at about 67 percent of full power in a coastdown mode to a refueling shutdown.
Observed changes in plant parameters during the event indicated an individual jet pump failure had t
occurred.
In accordance with T.S.,
an orderly plant shutdown was begun to bring the unit to cold shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
i The plant parameter changes reported by the licensee were (1) generator l
electrical output decreased from 539 to 511 MW electrical, (2) core thermal i
power decreased as indicated by decreased APRM readings and steam flow tg the turbine, (3) indicated total core flow increased from 97.6 to 104.7 x 10 lb./hr., (4)coreplatedifferentialpressuredecreasedfrom16.1 tog 3.8 psid.,and(5)Brecirculationloopflowincreasedfrom49to54x10 gpm j
while A recirculation loop flow remained at 49 x 10 gpm.
These changes were readily observed by the operator in the control room and it was postulated j
that a jet pump had failed.
Individual jet pung readings were taken, the jet pump operability surveillance was performe.1, and an apparent failure of jet i
pump No. 13 was determined.
l Following vessel head removal and defueling, TV camera and visual inspections of the jet pumps and vessel annulus revealed the hold-down beam assembly of the suspect jet pump had broken across its ligament sections at the mean i
diameter of the bolt thread area. Failure of the beam assembly resulted in pump decoupling at the diffuser connection.
Subsequent insitu ultrasonic i
examination of all other jet pump hold-down beams, using a special UT technique developed by General Electric (GE), revealed ultrasonic indications of cracking at the same 2) cation in 6 of the remaining 19 beams examined.
Initial estimates of crack depth ranged from 6 to 20 mils. A sketch of the typical jet pump assembly is shown in Figures 1 and 2.
t On March 15-16, 1980, insitu ultrasonic jet pump hold-down beam assemblies at Qua i
refueling).
One beam was found to contai i
in excess of 100 mils depth in the same 1 DUPLICATE DOCUMENT
[
l Entire document Previously entered into system under.
On March 28, 1980, Boston Edison reported revealed crack indications in three (3) h p
h No.
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