ML20035E029
| ML20035E029 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 04/02/1993 |
| From: | Zamek J SAN LUIS OBISPO MOTHERS FOR PEACE |
| To: | Bechhoefer C, Kline J, Shon F Atomic Safety and Licensing Board Panel |
| Shared Package | |
| ML16342A052 | List: |
| References | |
| CON-#293-13853 OLA-2, NUDOCS 9304140195 | |
| Download: ML20035E029 (1) | |
Text
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l ggj3 PROD. & UTIL FAC.d.6'k.32 3 M -2 DOCKET NUMBER yUJ ?
.~ h r.o April 2, 1993 93 TK -7 P4 3 9 Atomic Sofety and Licensing Board Administrative Judges Charles Bechhoefer, Chairman Jerry Kline Frederick Shan U.S. Nuclear Regulatory Commission Ucshington, DC 205S5
Dear Sirs:
The San Luis Obispo Mothere for Peace informs you and those on the service list of octions that it hos token regarding information discovered concerning safety-related and non-sofety-related cable degradotion problems at the Diablo Congon Nuclear Power Plant.
Son Luis Obispo Mothers for Peace consultants at MHB Technical Associates, Greg Minor and Steven Shelly, have shared this information with the NRC.
Their letter and documents are ottoched.
A conference cc11 took piece this morning; the NRC is investigating this issue and will remain in contact with Greg Mince and Steven Shelly.
l Sincerely, k
JillZomEk,6 Treasurer Son Luis Obispo Mothers for Peace P.O.
Box 169 Pismo Beach, CA S3448 l
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I l
9304140195 930402 pOj-PDR ADOCK 05000275 G
Technical Associates i
Consultants on Energy & the Environment l
VIA FEDERAL EXPRESS l
I April 1993 Dr. Ashok C. Thadani, Director Division of Systems Technology Office of Nuclear Reactor Reguation U.S. Nuclear Regulatory Commission One Widte Flint North, Room 8 El 1
11555 Rockville Pike Rockville, Maryland 20852
Dear Dr. Thadani:
We tried to reach you today by telephone, but were unsuccessful. Accordingly, we are transmitting by Federal Express information for your evaluation and follow-up as appropriate conceming safety-related and non-safety-related cable degradation problems at the Diablo Canyon Nuclear Power Plant (DCNPP). This information was received partially from public sources and partially from our participation as technical consultants to San Luis Obispo Mothers for Peace in connection with the Diablo Canyon operating license amendment proceeding (construction period recapture).
The sequence of events involved in this issue stans initially with an electrical fire which occurred at Diablo Canyon on February 5,1993. The fire involved a non-safety-related system. Specifically, an electrical fire occuned in the DCNPP Unit 1 cable spreading room as a result of an electrical ground in the No.11 Circulating Water Pump. We believe that the pump was eventually restored to operability on 1
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or about February 10,1993, and during the interim the plant operated at a reduced power level commensurate with the availability of a single operable Circulating Water Pump.
Subsequently, by way of a copy of the February 17,1993, Region V " Morning Report", we became aware that Pacific Gas and Electric (PG&E) had pulled an unknown length of Unit 1,12 kV circulating water pump cable that " exhibited increasing groundfauh indications". According to the "Moming Repon" entry:
9304140202 930402 PDR ADOCK 05000275 6
pm 1723 Hamilton Avenue Suite K, San Jose, CA 95125 Phone (408) 266-2716 Fax (408) 266 7149 l
g I
Approximately 200ft. ofthe total 440ft. ofcable showed signs of Insulator andground conductor degradation. The licensee suspects that afluid ofunknown originfound in the associated conduit moy be the cause ofthefailure. Initiallicensee contact with the vendor (Okonite) indicates that the degradation is unprecedented and has not been seen by the industrypreviously. The licensee, the vendor, and a private licensee contractor are performing analysis on the cable. Results ofanalysis is expected to be complete by 2/27/93.
The Region is monitoring licensee evaluations.
Subsequent to this information, we received (today) from San Luis Obispo Mothers for Peace an extract ofinformation from a PG&E Onsite Safety Resiew Group (OSRG) November 1992 Monthly Report. The extract is enclosed with this letter. In short, the OSRG document indicates that there have been three occasiens since 1989 (the most recent of which was apparently in November 1992) in which Auxiliary Salt Water (ASW) system 4.16 kV safety-related cable has failed, apparently due to submergence. PG&E apparently evaluated this situation and determined that it was not reportable, apparently due to the fact that the cable's design basis does not include submergence. We have searched the NRC's Bibliographic Retrieval System (BRS) public docmnent computer system and can find no instance of PG&E reporting these failures dating back to October 1992.
The fact that the cable design basis does not include submergence seems to us to beg the issue. The facts apparently are that there have been three ASW cable failures due to a cause that PG&E does not fully understand in the last three years.
The safety significance of the ASW system is not in dispute --it is a safety-related system which serves as the functional link between safety-related decay heat removal systems and the ultimate heat sink (the Pacific Ocean). Furthermore, the Diablo Canyon IPE results indicate that without considering the cable degradation the ASW system is responsible for about 7% of the internal events severe accident frequency at Diablo Canyon.
Our concern is that the cable degradation is a new failure mode which is not reflected in the IPE, not reflected in the environmental qualification program, and not reflected in the maintenance / surveillance program, and which may make the plant more vulnerable to a severe accident. In addition, we are concerned about the attitude conveyed in PG&E's apparent decision that these potentially common-i mode cable failures are not reportable to the NRC. Further, the PG&E document enclosed with this letter opines that the cable degradation has resulted from "repeatedsubmergence over the past 20 years", (or since the 1970s) although the
l-3 plant has been in operating only since the mid-1980s. This im d
of safety-related cable back to the period before an operating licens There are several questions about these matters which we believe nee addressed quite rapidly:
Was the NRC aware of the three ASW cable failures at 1.
Diablo Canyon prior to now?
)
Has PG&E reported the three ASW cable failures to the NRC, 2.
and,if so, by what means?
If not, does the NRC agree with PG&E's reportability 3.
evaluation?
Is the 2/5/93 Circulating Water System fire related to 4.
submergence-induced cable degradation?
Is the 12 kV Circulating Water System cable degradation noted by PG&E in February 1993 related to the 4.16 kV ASW 5.
cable degradation discovered by PG&E in 1989-19927 What assurance is there that the ASW system is and will 6.
remain operable given the observed pattern of cable degradation due to submergence?
What is the cause (or causes) of the submergence, and is the 7.
submergence the cause of the degradation, a contributing l
factor to the degradation, or merely a coincidence?
Do PG&E and the NRC understand the nature of the 8.
degradation mechanism sufficiently to preclude it from occurringin the future?
Have PG&E and/or the NRC conducted inspections of the 9.
ASW and CWS cabling (and any other cabling potentially subject to this failure mechanism) to evaluate the status of the cable?
We would appreciate the opportunity to discuss this matter with you. W f
this matter to your attention as a result of our obligation to promptly repor concerns to the NRC, and we believe that the situation described herei l
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4 t attention. Ifyou have any sufficiently serious that NRC should give it very promp l
h ad address and questions, please do not hesitate to contact us at the etter e telephone / fax numbers.
l Sincerely, km l
Q Steven C. Sholly l
Gregory C. Minor Senior Censultant -
Vice-President MHB Technical Associates MHB Technical Associates
Enclosures:
- 1. PG&E OSRG Monthly Report extract, November 1992.
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- 2. NRC Daily Status Report, Diablo Canyon, Event 25029.
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- 3. NRC Region V Moming Report,2/17/93, page 3.
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t e
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ENCE0SURE 1 PACIFIC GAS & ELECTRIC COMPANY DIABLO CANYOH POWER PLANT
~
Onsite Safety Review Group (OSRG)
November 1992 Honthly Report from the
SUMMARY
The following items su-rarize the OSRG's observations November meetings.were reviewed are listed in Attachment 1.
ble The recent f ailure of a 4kV auxiliary saltwater pump motor is the third of this type in the past three years.
1.
Seismic restraints for monorati hoists, designe being 2.
installed after use.
Two OSRG concerns from the October mon 3.
CESCRIPTION Generally, where concerns The following items were discussed by the OSRG.
exist, they have been discussed with the appropriate TRG Chairm licable.
responsible department head and an AR has been initiated, if app Hi-Pot (test) on ASW PP Motor 1-2 4kV Cable 1.
NCR DC1-92-EM H054:
Failed.
A recent failure of the ASW 1-2 feeder cable is The OSRG DCPP documented f ailure of this type in the past three years.
CONCERN:
has concerns regarding repertability (i.e., outside design bas i
the the 40 year cable life potentially is invalidated) and regard ng Jack of documentation for the acceptability of potentially deg There are twelve total ash' purp cables, both units i
l cable.
NOTE:
inclusive; two have experienced f ailures.
Design basis reportability was mentioned by Regulatory The OSRG member asked the TRG to RESOLUTION:
Preliminary indication is that Cor'p11ance during a TRG ceeting.
address this issue at its next meeting.The cable design basis does not the condition is not reportable.
The OSRG will continue l
include submergence, the probable root cause.
to track this concern.
The concern regarding lack of documentation for the accep the potentially degraded condition was presented to th attending OSRG member.
l Analysis update to address this issue.
~
OSRG Hovember 1992 Monthly Report Page 2 of 5 The OSRG consensus is that the cable is not rated for long term l
submergence, and therefore, the cable is not failing to meetHowever, submergence requirements (i.e., not outside design basis).
degradation of the cables, due to submergence, is a potential i
(The cable is not designed for l
unreviewed safety question.
The Safety submergence but is being exposed to this condition.)
Analysis requested above by the OSRG should address this concern.
The first failure of a hi-pot test on this type of cable t
The second failure was in May 1992 DISCOSSION:
was in October 1989 on ASW PP 2-2.All three insulation f ailures were experienced !
on the But 14E feeder.
l in the vicinity of the first circuit pull box just outside the turbine This is the low point in a long horizontal run of cable just The fact that water has been documented i
building.
west of the turbine building.in these pull boxes, and the fact that the most re f
approximately 3 days after a rain shower (water found in ASW PP 1-2 i
associated pull box 2 ft. above cable elevation), leads to a strong i
preliminary conclusion that the cable has been degraded due to repeated sube.ergence over the past 20 years.
[
Walkdown of Plant-Mounted Monorail Hoists. cer OSRG 0:en item 92-0; Titems to Monitor for 1RS Outace), te Assure Seismic Clips Were
'2.
i Reinstalled.
f Seismic restraints for monorail hoists, designed to prevent CONCERN:
interactions with nearby safety related equipment, are not being installed after use in all cases. Controls to assure that plant-mounted trolleys and hoists are secured are not consistently Mechanical Maintenance has placed steps in applicable implemented.
work orders, at the OSRG's request.
Recently, Electrical Maintenance has been found to have the same problem.
The OSRG initiated AR A0286094 recently on a missing hoist RESOLUTION:
seismic stop above Centrifugal Charging Pump (CCP) 1-1.-
An AE was i
issued to request a seismic interaction analysis of this condition and another AE was issued to request rnodification of electrical w:rk orders Work order to include steps to secure hoists and seismic stops.was initiated to re C0107374 This issue will be followed via the AR and the OSRG's Open monorail.
Item 92,02.
DISCUSSION:
In 1991 the OSRG issued AR A0235110 requesting that Mechanical Maintenance establish procedural guidance to ensure applicable work orders contained steps to secure monorail hoists.
Riggers who use such equipment are in the Mechanical Mainten would be added to RT work orders and planners would be directed to add section.
instructions to CM work orders.
i Onsite Safety Review Group November 1992 Monthly Report if the TRG was t
Nonconformances llowing NCRs or,fic critique
/
10 The CSRG either ettended TRGs for the fo Speci CR package.ible Chairman and/or ARs have not attended, reviewed the completed Ncoment 1
been initiated, if applicable.Hi-Pot (test) on ASW P l Failed.
DC1-92 EH-N054:(OSRG Surveillance 92-055.kwr)
Regulatory Correspondence NRC Inspection Report No.
2.
HRC letter to PG&E, Notice of Violation, 92-16,. dated July 7, 1992. Chron192621.
l tion in NRC Inspection PG&E 1etter to NRC, Reply to Notice of Vio a61, dated Jul Report No. 92-17, PG&E Letter No. DCL-92-1
/
92-01, Revision 1.
Chron193142 PG&E letter to NR'C, Response to Generic letterE Le Reactor Vessel Structural Integrity, PG&
June 30,1992 Chron192218.
OSRG Open Item 92-02 Miscellaneous items Walkdown of plant-!nounted monorail hoists, per.-to ass
/
3.
(Items to Monitor for 1R5 Outage)92-052.rcs) a)
i (OSRG Surveillance f an blade deformation.
reinstalled.
TES evaluation of CFCU imbalance due to
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(OSRG Surveillance 92-054.bal)OE f b)
OE 92-20, Rev. 1:
c)
Damper Blades.
Cycle 6 Core /S3 Tube Plugging d) DCP H-47225:
1
J ENCLOSURE 2
+.................................+
4._...................--+
l POWER REAC10R l
jEVENT NUMBER:
25029 l
...................................+
+...._.................+
4_.............................................. 4.............................+
l FACILITY: DIABLO CANYON REC 10N:
5 (NOTIFICATION DATE: 02/06/93 l
)
l UNIT:
[3])W.4-L@,[2] W-4.LP CAl'NOTIFICATIONTIME:
')
[]']
STATE:
00:56 [ET !
02/05/93]'
lRX TYPE:
EVENT DATE:
4.........
.................................... 4 EVENT TIME:
21:06[PST)'
NRC NOTIFIED BY: GOELZER lLAST UPDATE DATE:
02/06/G3 l
l'HQOPSOFFICER:
DICK JOLLIFFE
+...---.....-.-..--------..---+
4................................................+
NOTIFICATIONS l EMERGENCY CLASS: UNUSUAL EVENT
+....-..................----..+
10 CFR SECTION:
l FRANK WENSLAWSKI ROO l
.AAEC 50.72(a)(1)(1)
ENERGENCY DECLARED l JAMES RICHARDSON E0 I
'STINEDVRF FEMA l
l l
1
+.....+..........+......
4........+.............
4..+......._4................
+
' UNIT l SCRAM CODEjRX CRITjlNIT PWR!
INIT RX MODE lCURR PWR; CURR RX MODE i
...............+._....
4..
....+..
_........+..
.4 1
l l
l
......+...................................._........l._
4 EVENT TEXT
+....................._..................._........_...........................+
l. ELECTRICAL FIRE IN 12 KV CABLE SPREADING ROOM LASTING LESS THAN 10 MIN -
l
'i i
l AN ELECTRICAL FIRE OCCURRED IN THE UNIT 1 12 KV CABLE SPREADIN3 ROOM
! DUE TO AN ELECTRICAL GROUND IN 1 0F 2 CIRC WATER PUMP MOTORS (#11).
l
! LICENSEE REDUCED POWER TO 46'/. TO REMOVE til CIRC WATER PUMP FROM SERVICE.
j (CIRC WATER PUMP IS NOT A TECH SPEC ITEM).
l I
s
! LICENSEE CALLED THE CALIFORNIA DEPARTMENT OF FORESTRY TO ASSIST IN FIGHTIN 1
i
! THE FIRE.
THE FIRE LASTED LESS THAN 10 MINUTES AND IS PRESENTLY OVT.
l l SMOKE HAS BEEN CLEARED FROM THE ROOM.
THERE WERE NO PERSONNEL INJURIES.
j 8'
i l LICENSEE IS MAKING AN ENTRY INTO THE ROOM TO DETERMINE THE CAUSE AND l
I l EXTENT OF DAMAGE.
i
,i DURING THE POWER REDUCTION, THE DIGITAL R00 POSITION INDICATIONS DIO NOT l
c FOLLOW THE CONTROL ROD INDICATORS AS CONTROL RODS WERE INSERTED INTO THE i
, CORE.
LICENSEE DECLARED CONTROL BANK 'D' (9 CONTROL RODS) INOPERABLE.
l l
TECH SPEC 3.1.3.1 REQUIRES LICENSEE TO RESTORE CONTROL BANK 'O' 10 OPERABLE STATUS WITHIN 72 HOURS OR TO PLACE UNIT 1 IN AT LEAST HOT SHUTDOWN MODE
!'WITHINTHEFOLLOWING6 HOURS.
I & C TECHNICIANS ARE INVESTIGATING THE CAUSE AND DETERMINING CORRECTIVE ACTIONS.
l i
l
! LICENSEE NOTIF]ED STATE AND LOCAL OFFICIALS AND THE NRC RESIDENT INSPECTOR j
l AND WILL ISSUE A PRESS RELEASE.
i,
!! * *
- UPDATE AT 0216 BY COELZER EN1ERED BY N00 JOLLliFE * *
- l o
l LICENSEE TERMINATED THE UNUSUAL EVEN1.
l
' AT 2232 (PST) ON 02/05/93, I
i l LICENSEE DETERMINED THAT THE ELECTRICAL GROUN
! CAUSED THE LOAD BANK IN THE 12 KV CABLE SPREADIN i PAINT, DIRT, AND DVST IN THE ROOM. THERE WAS NO ACTUAL FLAME; i
' IN THE ROOM CAUSED THE f!RE ALARM.
NO EQUIPMENT IN.THE ROOM WAS DAMAGED.
j l
l LICENSEE NOT! fled STATE AND LOCAL OfflCIALS AND THE NRC R j
H00 NOTIFIED R500 WENSLAWSKI,
- 0F THE TERMINATION OF THE UNUSUAL EVENT.
]
t NRR EO RICHARDSON, FEMA STINEDURf.
+............._......._______....___..............____........_...............,
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f l
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.I RtGION V MORNING RE POR T PAGE 3 fECRUARY l7, 1993 L s c en.cc/F ac i n i t y.
Not11itat:on Partfir Gas & flectric Co MR Number 5-93 0010 Date 02/11/93 Daablo Canyon I Avsla Orath, California IE L E PHONE Call IROM RI Dockets 50-275 PWR/W-4-LP Subject CIRCULATING WATER PUMP POWE R CABLE DEGR Alail0N-UPDA TE TO LVENT REPORT NUMBER 25029 Ocportable Event Number N/A Dascession-THE VWELVE KV CIRCULATING WATER PUMP CABLE THAT E xtilDITED INCRE ASING GCOUND F AUL T INDICATIONS WAS DEENIRGlZED AND PUILED FROM IIS UNDERGROUND CONDtil l APPROXIMATELY 200 FT. OF THE TOTAL 440 Fi Of CARLE SHOWED SIGNS Of INSULAIOR AND GROUND CONDitCTOR DEGRADATION. THE 1ICENSEE SilSPECTS IHAT A F LUID OF UNKNOWN ORIGIN F OUND IN THE ASSOCI ATED CONDUli MAY BE THE CAtl3E OF THE FAILURE. INITI AL LICENSE E CONT ACT WIIH THE VENDOR 10KONITE)
INDICATES THAT THE DEGRADATION IS UNPRECEDINTED AND HAS NOT DEEN SEIN DV THE INDUSTRY PREVIOUSLY.
THE LICENSEE. THE VENDOR AND A PRIVATE LICENSEE CONTRACTOR ARE PERFORMING ANALYSIS ON THE CABLE RE SUtis OF ANALYSIS IS E XPECTED TO DE COMPLE TE RY 2/21/93.
THE REG:0N IS MONiiORING LICE NSE E IVALUA110NS. UNIT I HAS RESUMED FULL POWEit OPERAIlONS Re<)t onal Ac t non -
N/A Cont as :
d A p r}
(5101975-0310
=
e 4
4 G
f a
m
.i-A.. !
1 93 rp -7 P A 55 Certificate of Service i
I hereby certify thct copies cf the foregoing Intervenor Son Luis Obispo Mothers for Peace ("SLOMFF"3 Motion for Leave to File Additianoi Discovery Re: Okonite Cables with Bonded Jockets; Intervenor SLOMFP Supplemental Interrogatories Related to SLOMFP First Set of Written Interrogatories and Requests for the Production of Documents to Pacific Gas and Electric Company; Intervenor SLOMFP Supplemental Interrogatories Related to SLOMFP First Set of Written Interrogatories and Requests for the Production of Documents to the NRC Staff Re: Okonite Cables with Bonded Jockets; Letter dated 2/2/S3 and ottochments from SLOMFP to the Atomic Sofety and Licensing Board have been served upon the following persons by U.S. mail, first class.
Office of Commission Apcellote Administrative Judge Adjudiention Charles Bechhoefer, Chairman U.S.
Nuclear Regulatory Commission Atomic Sofety and Licensing Board Washington, DC 20555 U.S.
Nuclear Regulatory Commission Washington, DC 2055S Administrative Judge Jerry Kline Administrative Judge l
Atomic Sofety and Licensing Board Frederick J. Shon U.S. Nuclear Regulatory Commission Atomic Sofety and Licensing Board Washington, DC 20555 U.S. Nuclear Regulatory Commission Washington, DC 20555 Edward O'Neill Ann P.
Hodgdon, Esq.
Peter Arth, Jr.
Office of the General Counsel Truman Burns U.S. Nuclear Regulatory Commission Robert Kinosion Washington, DC 20555 Peter G.
Fairchild, Esq.
California Public Utilities Commission Joseph B.
- Knotts, Jr.,
Esq.
505 Von Ness Avenue Winston & Strown Son Francisco, CA S9102 1900 L Street, N.W.
Washington, DC 20005 Adjudicatory File Secretary of the Commission U.S.
Nuclear Regulatory Commission Docketing and Service Branch Washingten, DC 20555 U.S. Nuclear Regulatory Commission Washington, DC 20555 Robert R.
Wellington, Esq.
Diablo Canyon Independent Sofety Committee 957 Coss Street, Suite D Monterey, CA S3590 Christopher Ucrner, Esq.
Richard Locke, Esq.
Pacific Gas and Electric Co.
77 Beale Street Son Francisco, CA S9106 Dated April 2, 1993, San Luis Obispo County, CA Jill ZomEk
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