ML20207K783
| ML20207K783 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/29/1988 |
| From: | Tiernan J BALTIMORE GAS & ELECTRIC CO. |
| To: | Russell W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| REF-PT21-88, REF-PT21-88-138-000 PT21-88-138, PT21-88-138-000, NUDOCS 8810170020 | |
| Download: ML20207K783 (4) | |
Text
b e
e 6 B ALTIM O RE GAS AND ELECTRIC CH ARLES CENTER P. O.5CX 1475
- BALTIMORE. MARYLAND 21203 JostPH A.Titaw AN Vict Patgipth?
l N sCkt AR E 8 vin 9 7 September 29, 1988 U
S. Nuclear Regulatory Com:nissica Region One 475 Allendale Road l
King of Prussia, PA 19406 1
ATTENTION:
W, T. Russell Regional Administrator SUBJ ECT:
Calvert Cliffs Nuclear Power Plant Uni t Nos. 1 & 2; Docket Nos. 50 317 6 50 318 Notification of a Defect in A:tphenol SAMS Model 205 0034 Electrical Penetration Assembiv. ner 10 CFR 21 l
Centlecen:
l l
Ve have identified a deviation in Amphenol SAMS Model 205 0034 Electrical Penetration Assamblies. We evaluated the deviation, and determined such deviation can be considered a manufacturing defect, as defined in 10 CFR 21.
l This defect was reported te ne on today and wn notified Mr. David l
Liaroth by telephone today.
Enclosed is our written report, as required by l
I Should you have any further questions regarding this snatter, we will be i
pleased to dis:uss thern with you.
1 i
Very truly yours,
~'
I
,k7'A.7l.m 1
- r.
l
'Jne lo sure s 1
J AT/j pte/ghb l
l l
C310170020 G50920 l
PDR ADOCK 05000317 S
FCC ig 1
..s.o Mr. W. T. Russell September 29, 1988 Page 2 cc:
D. A. Brune, Esquire J. E. Silberg, Esquire T. E. Murley, NRC (3 copies)
R. A. Capra, NRC S. A. McNeil. NRC D. C. Trimble. NRC T. Hagette, DNR 1
i.
l r
i l
k
o
.5 ATTACitMFELA The forsat of this Attachment conforms to the list of information required per 10 CFR 21.21(b)(3).
.s (i)
Name end address of the individual informing the Commission.
Joseph A. Tiernan Vice President, Nuclear Energy Baltimore Cas & Electric Company Post Office Box 1535 Lusby, MD 20657 (ii)
Identificacion of the basic component which contains a defect.
Amphenol SAMS Model 205-0034 Electrical Penetration Assembly (iii)
Identification of the firm supplying the basic component which contains a defect.
Amphenol SAdS (iv)-
Nature of the defect and the safety hazard which could be created by such defect.
Electrical connection studs on Amphenol SAMS Model 205-00'4 electrical penetration assemblies (EPA) have been found defective.
This defect was identified during a work activity which required disconnecting cables from the EPA studs.
During the cable disconnection, eight (8) studs broke at the connection of the electrical penetration assembly.
A metallurgical analysis was performed and revealed that the studs which broke were made of C11000 copper alloy and that the C11000 had degraded.
The vendor prints specify that C10200 copper alloy be used for the studs. Analysis indicates, for C11000 studs to degrade, they would have to be heated above 500 F in a hydrogenated environment.
Oxygen in the C11000 copper alloy then reacts with the hydrogen at high temperatures to create steam. The steam then creates small cracks at the grain boundaries and weakens the metal.
The C10200 copper alloy does nor degrade because it lacks the oxygen necessary to react with hydrogen. An inspection indicated that all C11000 studs were degraded to varying degrees, and that none of the C10200 studs were degraded.
Metallurgical analysis also concluded that no fatigue mechanism exists for *.he C11000 studs.
Our investigation concluded that the degradation occurred during manufacturing.
Tests were performed on the remaining unbroken, but degraded C11000 studs on Unit 1 to provide reasonable assurance that the studs subjected to a calculated load will withstand a design basis earth-quake. Twenty three (23) degraded C11000 studs were tested. Twenty-two (22) of these studs passed the test. The one stud that failed the test was believed to have been weakened from the stress imposed during disconnection of the cable from the stud, which involved the removal of heat shrink tubing.
a
'*6 4f '
We.aro reporting this deviation to notify others of a potential safety p roblem'.
The reduction in the mechanical properties of the specified material could lead to failure of the stud and loss of power to the equipment connected to the stud.
(v)
. The date on which the information of such defect was obtained.
September 28, 1988.
It should be noted that the Resident Inspector was in continuous communication with the licensee during resolution of this event.
(vi)
The number and location of all such defective components identified in l
use at Calvert Cliffs Unita 1 and 2 (NOTE:
testing is not connlete for Unit 2):
Ef6 Location
_ No. of ' Defec ts 1ZEB6 Containment Unit 1 Eight
( 8) 1ZWB1 Containment Unit 1 Eighteen (18) 1ZWB7 Containment Unit 1 Seven
( 7) 2ZWB2 containment Unit 2 One
( 1) 1ZWB7 W. Electrical Pene. Room, Unit 1 One
( 1) 2ZWB2 W. Electrical Pene. Room, Unit 2 One
( 1)
Total studs:
36 (vii)
The corrective action which has been taken:
For Unit 1, the circuite for safety related equipment have been placed either on studs verified to be C10200 or relocated to Conax EPAs, which are not of this configuration and are not defective.
For Unit 2, a Justification for Concinued Operation (JCO) has been prepared and approved by our plant on site Safety Review Committe, which concluded that operation of Unit 2 till the next Refueling Outage would not pese a significant safety hazard.
The name of the organization responsible for the corrective action:
Baltimoro Cas & Electric Company.
The length of time that was taken to complete the action:
The Unit 1 outage was extended to test, evaluate and reconnect the l
1 FPAs from June 16, 1988 to June 30, 1988. The Unit 2 EPAs will be
[
taken out of service, tested, evaluated and cables reconnected no r
later than at the conclusion of the next Refueling Outage, scheduled to beg!n March 31, 1989.
[
(e sii) Any advice related to the defect that has been, is being, or will be given to purchasers or licenseep:
Amphenol SAMS is no longer in the business of making nuclear electrical penetation assemblies.
Licensees should be cautioned in disassembling the connections, as disassembly can be more damaging l
than testing.
2 i
i i
l,___
____.,m
_,,_,..,m,
_