ML20203C172
| ML20203C172 | |
| Person / Time | |
|---|---|
| Issue date: | 02/19/1998 |
| From: | Richards S NRC (Affiliation Not Assigned) |
| To: | Roe J NRC (Affiliation Not Assigned) |
| References | |
| OREM-98-003, OREM-98-3, NUDOCS 9802250105 | |
| Download: ML20203C172 (11) | |
Text
Rirmry 19,199B i
4
, e MEMORANDUM TO: Jack W. Roe, Acting Director Division of Reactor Program Management FROM:
Stuart A. Richards, Chief lOrigimi adgni byl Events Assessment, Generic Communications and SpecialInspections Branch i
l Division of Reactor Program Management
SUBJECT:
OPERATING REACTORS EVENTS BRIEFING FEBRUARY 18,1998 - BRIEFING 98-03 On February 18,1998, we conducted an Openting Reactors Events Briefing (98-03) to inform senior managers from the Offices of the Comniission, AEOD, NRR and regional offices of selected events that occurred since our last briefing on February 4,1998. Attachment 1 lists the attendees. Attachment 2 presents the significant elementa c U.e discussed event.
The statements contained in the attached briefing slides represent the best information currently available to the NRC. Future followup could produce new information that may alter the NRC's current view of the event discussed.
Attachments:
As stated (2) cc w/atts:
See next page CONTACT: Kathy Gray, NRR (301) 415-1166
- SEE PREVIOUSE CONCURRENCE DISTRIBUTION: (w/atts)
(CeWeltgesi PUBLIC LKilgore, SECY PECB R/F KGray RBenedict DOCUMENT NAME: GnKAG\\ORTRANS To receive e copy of tNo document, tr.dieete in the boa: 'C' = Copy without attachment / enclosure
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S. Collins, NRR (0-12G18)
B. Wetzel, NRR (0-13/D/18)
F. Miraglia, NRR (0-12G18)
C. Carpenter, NRR (013/D18)
F. Gillespie, NRR (0-12G18)
- 8. Boger, NRR (0-14E4)
- 8. Sheron, NRR (0-12G18)
J. Zwolinski, NRR (0-14H3)
E. Adensarn, NRR (013E4)
G. Lainas, NRR (0-7D26)
G. Holahan, NRR (0-8E2)
D. O'Neal, NRR (0-10E4)
L. Spessard, NRR (0-9E4)
M. Markley, ACRS (T 2E26)
T. Martin, AEOD (T-4D18)
C Rossi, AEOD (T-4A9)
F. Congel, AEOD (T-4D28)
R. Barrett, AEOD (T-4A43)
S. Rubin, AEOD (T iD28)
M. Harper, AEOD (l-4A9)
W. Leschek, AEOD (T-4A9)
G. Tracy, EDO (0-16E15)
J. Gilliland, PA (0-2G4)
D Morrison, RES (T-10F12)
W. Hill, SECY (016G15)
H. Miller, Region I C. Hehl, Region i L. Reyes, Region il L. Plisco, Region 11 S. Vias, Region 11 A. Beach, Region ill G. Grant, Region ill E. Mershoff, Region IV P. Gwynn, Region IV K. Perkins, Region IV/WCFO G. Fader, INPO J. Zimmer, DOE I
LIST OF ATTENDEES OPERATING REACTORS EVENTS FULL BRIEFING (98-03)
February 18,1998 NAME OFFICE NAME OFFICE R. Benedict NRR B. Holian OCM/SAJ S. Richards NRR D. Castleman OCM/NJD T.Koshy NRR J. Rosenthal AEOD K. Connaughton NRR C. Carpenter NRR B. Wetzel NRR J. Carter NRR K. Gray NRR TELEPHONE ATTENDANCE (AT ROLL CALL)
Reaions Resident inspectors Region i Region 11 P. Krohn, Prairie Island Region 111 Misc.
A. Lohmeier, Region I, DRS ATTACHMENT 1
~
l 98-03 OPERATING REACTORS EVENTS BRIEFING 98-03 LOCATION:
0-10B11, WHITE FLINT WEDNESDAY, FEBRUARY 18, 1998 11:00 A.M.
PRAIRIE ISLAND, UNIT 2 REACTOR COOLANT LEAKAGE FROM UNIS0LABLE CRACK IN CONTROL R0D DRIVE MOTOR TUBE PRESENTED BY:
EVENTS ASSESSMENT, GENERIC COMMUNICATIONS AND SPECIAL INSPECTION BRANCH DIVISION OF REACTOR PROGRAM MANAGEMENT, NRR Attadrmt 2 I
98-03 PRAIRIE ISLAND, UNIT 2 REACTOR COOLANT LEAKAGE FROM UNIS0LABLE CRACK IN CONTROL R0D DRIVE MOTOR TUBE JANUARY 23, 1998 ERDELEM A SMALL BUT UNIS0LABLE REACTOR COOLANT LEAK WAS DISCOVERED COMING FROM THE PRESSURE HOUSING OF AN UNUSED PART-LENGTH CONTROL R0D DRIVE MECHANISM (CRDM).
SAFETY SIGNIFICANCE LOSS OF PRESSURE B0bnvARY INTEGRITY, PLANT CONDITION e
JANUARY 22 REACTOR OPERATING AT FULL POWER.
O LEAKAGE INCREASED BY FACTOR OF 10 TO 0.2 GPM.
9 JANUARV 23 CONTAINMENT ENTRY.
LEAKAGE OBSERVED FROM G-9 PART-LENGTH CONTROL ROD DRIVE.
6 JANUARY 24 REACTOR SHUT DOWN.
DISCUSSION e
LEAK INITIALLY BELIEVED FROM CANOPY SEAL, BUT FOUND TO BE FROM PRESSURE BOUNDARY IN TAPERED TRANSITION JUST ABOVE THE CANOPY, CONTACT:
R.
BENEDICT, NRR/DRPM/PECB AIT: _NQ
REFERENCES:
10 CFR 50.72 #33634; SIGEVENT: ISD PN-3-98-11
PRAIRIE ISLAND, UNIT 2 98-03 e
THE TRANSITION INCLUDES A WELD CONNECTING 304 AUSTENITIC SS TO 403 MARTENSITIC SS.
THE 403 HAS BEEN " BUTTERED" WITH 309 SS WELD ROD.
O MECHANISM REMOVED FROM REACTOR VESSEL HEAD.
I e
UT INSPECTION SHOWED CIRCUMFERENTIAL INDICATIONS 5 INCHES l
LONG AND 3 INCHES LONG.
e UT COULD NOT MEASURE CRACK DEPTH OR RELATION TO WALL THICKNESS, BUT THE VISIBLE LEAK ON OUTER SURFACE WAS CENTERED IN THE 5 INCH INDICATION.
VISIBLE LEAK ABOUT 3/4 INCH LONG.
O RADIOGRAPHY SHOWED 4.5 INCH INDICATION IN SAME LOCATION AS 5-INCH UT INDICATION.
O VISUAL INSPECTION OF INTERNAL SURFACE, USING FLASHLIGHT AND MIRROR, SHOWED DISCONTINUOUS LINES ORIENTED CIRCUMFERENTIALLY AROUND APPROXIMATELY 250 DEGREES.
O ASSEMBLY G-9 SENT TO WESTINGHOUSE FOR EXAMINATION.
O AS OF 2/17/98, THE THREE REMAINING P/L CRDM ASSEMBLIES HAVE BEEN REMOVED AND EXAMINED ONSITE.
NO INDICATIONS SEEN.
O ALL FOUR HEAD PENETRATIONS WILL BE CUT AND CAPPED.
l
PRAIRIE ISLAND, UNIT 2 3-98 03 EVALUATION e
AS OF 2/17/98:
()
THE CRACK IS AT THE 403 - 309 BUTTERING INTERFACE.
()
MECHANISM CAUSING THE CRACK APPEARS TO BE OXIDE INCLUSION AT INTERFACE BETWEEN 403 SS AND BUTTERING, INDICATING PRE-EXISTING WELD FLAW.
C)
THE ASSEMBLY INCLUDES A SIMILAR WELD AB0VE THE STATOR.
THIS WELD IN ALL FOUR CRDM ASSEMBLIES SHOWED NO INDICATIONS WHEN UT TESTED ON SITE.
O ALL W PLANTS THAT HAD PART-LENGTH RODS HAVE HAD THOSE RODS REMOVED.
SHOULD A HOUSING RUPTURE DURING REACTOR OPERATION, THERE IS NO CONTROL R0D THAT COULD BE EJECTED.
O FULL LENGTH CRD MECHANISMS ARE MAGNETIC JACKS, HAVING NO SIMILAR DISSIMILAR-METAL WELDS.
LICENSEE AND INDUSTRY FOLLOWUP GD NORTHERN STATES POWER PUBLICIZED THE EVENT ON INP0 NUCLEAR NETWORK.
ED WOG ISSUED LETTER TO ALL W OWNERS AND INFORMED THE OTHER PWR OWNERS GROUPS OF THIS ISSUE.
ED WOG ISSUED SURVEY REQUEST TO W OWNERS REGARDING STATUS OF PART-LENGTH MECHANISMS.
RESPONSES DUE 2/19/98.
El PRAIRIE ISLAND, UNIT 1 HAS BEEN MONITORED AND INSPECTED FOR LEAKAGE: NO INCREASE IN PRIMARY LEAKAGE OR CONTAINMENT RADIATION.
I
PRAIRIE ISLAND, UNIT 2 98-03 NRC FOLLQWUE e
NRC ATTENDING W INSPECTION WORK Tl.IS WEEK.
9-.NRC REQUESTED WOG TO PROVIDE LIST OF AND RESULTS OF SURVEY OF PLANTS HAVING THIS CRD CONFIGURATION.
I PART LENGTH CRDM I;;"![*:,,'"'""P """ 2 Figure 1 of 3 T//5; 7q N yf N N
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