ML042940196
| ML042940196 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/05/2002 |
| From: | - No Known Affiliation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2003-0187 02-00932 | |
| Download: ML042940196 (2) | |
Text
C N()P-LP2001-01 CONDITION REPORT CR Number TITLE:
CRDM NOZZLE CRACK INDICATIONS 02-00932 DISCOVERY DATE I TME EVENT DATE TIME SYSTEM / ASSET#
2128/2002 1500 02/28/02 1500 064-02 NA EQUIPMENT DESCRIPTION Reactor Vessel Head DESCRIPTION OF CONDITION and PROBABLE CAUSE (If known) Summarize any attachments. Identify what, when, where, why, how.
0 Completion of Ultrasonic Testing (UT) on all 69 Control Rod Drive Mechanism (CRDM) Nozzles, R
using the 'under-head' circumferential probe, and subsequent confirmatory testing using the "top-I down" tool under Framatome procedure 54-ISI-100-08 has revealed additional CRDM cracks l
beyond those on CRDM nozzle # 3 as described and reported under CR 02-00891.
In total, there G
are indications of cracks on 5 nozzles:
N NOZLE #1 (location H8): Axial cracks, some with pressure boundary leakage.
A NOZZLE #2 (location G7): Axial cracks, some with pressure boundary leakage, and a partial depth T
circumferential crack of approx. 30 degrees. (Note: this crack is sufficiently small that there was no I
risk of nozzle failure - stresses had substantial margin before reaching.ASME code allowable values.)
o NOZZLE #3 (location G9): Axial cracks, some with pressure boundary leakage (CR 02-00891)
N NOZZLE #5 (location K7): Small axial cracks, predominantly below the weld, no leakage but requiring repair NOZZLE #47 (location D12): Small axial cracks, predominantly below the weld, no leakage but requiring repair Nozzles #1, 2, and 3 have leakage paths apparent on UT, which is corroborated by boric acid deposits on the reactor head. UT results with the 'top-down' tool also provide some evidence of carbon steel base metal corrosion at nozzles 2 and 3. Nozzle 2 also exhibits channeling of the alloy 600 material to a maximum depth of approximately 0.050 inches to form part of the leakage flow path. These effects must be considered during repair of the nozzles.
(There was initial suspicion of a small axial crack below the weld on nozzle #58 from output using the circumferential probe. However, the top-down tool, which is more comprehensive due to a greater number of probes, confirmed that there was no actual defect.)
SUPV COMMENTS I IMMEDIATE ACTIONS TAKEN (Discuss CORRECTIVE ACTIONS completed, basis for closure.)
Unlike the axial crack indications, the observed circumferential crack on CRDM nozzle #2 Is the type indentified In NRC bulletin 2001-01. However, due to its small size, the circumferential crack is not a safety concern. The 3 nozzles with pressure boundary leakage noted in this CR, i.e. nozzles #1, 2, and 3 are reportable per T.S. 3.4.6.2.a. This Issue was already reported under CR02-0891 on 2127/02 for nozzle #3, however, an update of that report will be needed. This CR will ensure the reporting requirements are satisfied.
Resolution of the issues will be addressed by CR 02-00891, which was classified as OSignificant-Root Cause".
QUALITY ORGANIZATION USE ONLY IDENTIFIED BY (Check one)
El Seol-Revealed ATTACHMENTS Quality Org. Initiated E Yes 2
IndividuaVlWork Group E
Internal Oversight Quality Org. Follow-up El Yes El No El Supervision/Management El External Oversight g Yes E No ORIGINATOR ORGANIZATION I DATE SUPERVISOR DATE PHONE EXT.
LANG, T LCM 2128/2002 LANG, T 3/5/2002 8116 Page 1 of 2 H53
NOP-LP-2001-01 CONDITION REPORT JoCR Number TITLE:
CRDM NOZZLE CRACK INDICATIONS 02-00932 SRO EQUIPMENT E
VALUATION IMMEDIATE ORGANIZATIO0N MODE CHANGE REVIEW OPERABLEREQUIRED INVESTIGATION REQUIRED NOIID RESTRAINT L
g3 Yes 0 No El Yes 10 No a3 WA 0 Yes i]
No
[] Yes il No NIA EdYes 0 No MODE ASSOCIATED TECH SPEC NUMBER(S)
ASSOCIATED LCO ACTION STATEMENT(S)
A L
-g~
ij#~
N
-1WI DECLARED REPORTABLE?
One Hour W1AAPPLICABLE UNIT(S) 0 NOPERABLE (Date/Time)
RYes EINo 1
}
P 2/27/02 / 1330
]Evat Required Other 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Ul E0 U2 E0 Both E
COMMENTS R
Refer to CR 02-0891. Made 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Non-Emergency update to the initial report (Event Number A
38732) to the NRC. Update was made via ENS at 1921, 3/5/02. The disposition of this CR will be T
tied to that of CR 02-0891. NRC Resident Inspector was also notified, as well as the applicable I
personnel listed in DB-OP-00002.
o Current Mode - Unit I Power Level - Unit 1 Current Mode - Unit 2 l Power Level - Unit 2 N
6 0
S SRO-UNIT 1 SRO - UNIT 2 DATE Ploeger, T Steenbergen, C 3/5/2002 CATEGORY/ EVAL ASSIGNED ORGANIZATION DUE DATE R REPORTABLE?
Yes O]No EO LERNNo.
ORPATREND CODES Comp Type I ID Resp u
REPORTASILITY REVIEWER I
Process I Activity/ Cause Code(s)
(If Cause T or W)
Org A Wolf, G SUPV HDW 0600 T
0 DATE MRS y
03/08/02 INVESTIGATION OPTIONS CLOSED BY DATE E Generic Impliations El Part 21
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