ML20045A657
| ML20045A657 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 05/28/1993 |
| From: | Warner C PACIFIC GAS & ELECTRIC CO., WINSTON & STRAWN |
| To: | Atomic Safety and Licensing Board Panel |
| References | |
| CON-#293-14004 OLA-2, NUDOCS 9306110165 | |
| Download: ML20045A657 (35) | |
Text
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[ M REATED CCRRESPONDENCE May 28, 1900
'93 j'jN -1 F U7 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of: )
) Docket Nos. 50-275-OLA_ Z.
Pacific Gas and Electric Company ) 50-323-OLA
) (Construction Period (Diablo Canyon Nuclear Power ) Recovery)
Plant, Units 1 and 2) )
)
PACIFIC GAS AND ELECTRIC COMPANY'S RESPONSE TO SECOND SET OF SUPPLEMENTAL INTERROGATORIES AND REQUESTS FOR PRODUCTION OF DOCUMENTS RE: CABLE FAILURES AT DIABLO CANYON NUCLEAR POWER PLANT FILED BY SAN LUIS OBISPO MOTHERS FOR PEACE Pacific Gas and Electric Company ("PG&E") herein responds to "Intervenor San Luis Obispo Mothers for Peace Second Set of Supplemental Interrogatories and Requests for Production of Documents to Pacific Gas and Electric Company Re: Cable Failures at Diablo Canyon Nuclear Power Plant," dated May 21, 1993 ("MFP's Second Set of Supplemental Interrogatories (Cable Failures)") . In accordance with the agreement entered into by PG&E and MFP concerning the scope of discovery at the May 12, 1993, prehearing conference, this response addresses MFP's Second Set of Supplemental Interrogatories (Cable Failures) in full. Copies of documents identified in Attachment 1 are being provided to the representatives of the San Luis Obispo Mothers for Peace ("MFP")
herewith, i
9306110165 930528 /
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II. MSWERS TO INTERROGATORIES IntgJronatory 1.:
Provide a copy of the specifications or other similar document [s] under which PG&E purchased the 4kV cable for which three failures are described in Diablo Canyon Nuclear Power Plant ["DCNPP"] Licensee Event Report ["LER"] 50-275/93-005
[ April 23, 1993).
Answer to Interrocatory 1:
PG&E is providing Specification No. 0702 dated July 15, 1971 which was the specification in effect for purchase of the three 4kV cables which failed.
Interrocatory 2:
Provide copies of any " Nuclear Notebook" entries generated by PG&E concerning the 4kV cable failures described in LER 50-275/93-005.
Answer to Interroaatory 2:
PG&E is providing copies of the following entries:
Subject:
Electrical Okonite Cable Failures, Failure Mechanism, Root Cause 9-1-92.
Subject:
Auxiliary Saltwater Pump Motor Power Cable Failed Hi-pot Testing, January, 1993.
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Subject:
Additional Power Cable Fault to Ground, i
February 1993.
Interrocatory 3:
Provide a copy of any documentation prepared by Okonite [or i others] which describe the design service conditions for the i 4kV cable for which three failures are described in DCNPP LER ;
50-275/93-005. I Answer to Interrocatory 3: i l
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4 The design service conditions for the 4kV cable are described in Specification No. 0702. See Answer to Interrogatory 1. ;
Interroaatory 4:
Describe how the actual service conditions for the as-installed 4kV cable compare or contrast with the design service conditions as described by the cable vendor.
Answer to Interroaatory 4:
The as-installed service conditions correspond with design service conditions described in Specification No. 0702. For example, portions of the 4kV ASW cables are installed outdoors in an underground duct bank. These actual cable locations correspond to the design service conditions of wet or dry locations, indoors or outdoors and in any raceway or underground duct.
Interroaatory 5:
Identify and provide copies of any procedures which PG&E utilizes to ensure that the design service conditions of the 4kV cables for the Auxiliary Salt Water ["ASW"] system are not exceeded in actual service.
Answer to Interrocatorv 5:
i PG&E is providing copies of the following procedures related to maintenance / testing of the ASW cables:
Maintenance Procedure MP E-17.1, AUXILIARY SALTWATER PUMP l l
MOTOR OVERHAUL l
Maintenance Procedure MP E-54.2, HIGH VOLTAGE TESTING OF ELECTRICAL EQUIPMENT Surveillance Test Procedure STP P-7A, PERFORMANCE TEST OF AUXILIARY SALTWATER PUMP J l
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Burveillance Test Procedure STP P-7B, ROUTINE SURVEILLANCE TEST OF AUXILIARY SALTWATER PUMPS Interrocatorv 1:
Identify and provide copies of any quality assurance and/or quality control audits [or similar documents such as quality surveillances or observations) which have been performed on the installation, operation, and/or maintenance of the 4kV ASW system cable.
Answer to Interrocatorv 6:
The circuit installation and termination inspection records for ASW circuitt 11, 12, 21 and 22 are provided herewith.
Also various quality control inspections and documentation relating to operation and maintenance of the ASW cables and i
systems are provided.
Interroaatorv 7:
Indicate whether PG&E believes that the three ASW 4kV cable failures described in LER 50-275/93-005 have the same root and contributing causes. Describe in detail the bases for PG&E's beliefs in this regard, and if the root and contributing causes are believed to be the same, please address whether
[and why or why not) PG&E believes the three failures should be considered to be " common mode" failures {within the meaning of " common mode failures" as that term is generally used in the practice of reliability and risk assessment).
Answer to Interroaatorv 7:
The root cause for the 4kV cable failures is still under evaluation. (The two in-service 4kV cable " failures" were not failures of the cables to perform their intended function, but in fact were events in which a fault was detected and isolated.) Even if the root cause were found to be identical for all three 4kV cable failures, this would not be considered a " common mode" failure event. !
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Common mode failures are mult.iple , concurrent, and dependent failures of identical equipment that fails in the same mode (NUREG/CR-2300) . However, since the three 4kV cable failure incidents have occurred over a long period of time, the likelihood of more than one cable failure occurring in a short period of time (24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) is negligible. Only common cause failures occurring within a short period of time are considered to be concurrent failures.
In the case of the 4kV cables, no evidence has been found that any measurable degradation is occurring that would cause the failure of redundant circuits at the same point in time.
It should be noted that the in-service " failures" were only annunciator indications of a fault. The cables themselves had a high probability of continuing to perform their required safety function even after receiving such an indication.
Actual cable failure occurred only after hi-pot testing was completed.
Interroaatorv 8:
Identify the nature of any lubricant employed in the installation of the 4kV ASW syrtem cable for which three failures are described in LER 50-275/93-005, and indicate whether the use of this lubricant was approved by the cable vendor.
Answer to Interroaatorv 8:
The original installation of the 4kV ASW system cables used Albentonite, a vendor-approved lubricant.
Interroaatorv 9:
Indicate whether, for any of the three 4kV ASW system cable failures described in LER 50-275/93-005, the outer neoprene
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. jacket for the cable was observed to be degraded in any way (e.g., abraded, scraped, peeled, etc.).
Answer to Interroaatorv 9:
There was no degradation of the outer neoprene jacket observed in either of the two ASW cables or the Bus 14D cable.
Interroaatory 10:
Describe the design and function of the cable pull box sump pumps mentioned on page 3 of 14 of LER 50-275/93-005.
Answer to Interroaatory 10:
The design and function of the cable pull box sump pumps is as follows:
Physical Description of as-built conditions:
The multi-compartment pull boxes (BPO 13 through 20) are located near the north west (Unit 1) and south west corners (Unit 2) of the turbine building. Pull box and pipeway covers are not leak tight. These pull boxes, and outdoor portions of the diesel fuel oil (DFO) pipeway which abuts the west side of the turbine building drain via floor drains to common 3' diameter sump manholes, SM-1 for Unit 1 and SM-2 for Unit 2.
The manholes are equipped with automatic submersible Class II pumps. The pumps for both units discharge, via 1" PVC pipes and the 4" PVC turbine b1dg. suilp transfer pipe (both of which are embedded in the bottom slab of the DFO pipeway), to the Unit 1 turbine building sump.
The Unit 1 boxes are located at a relative " low-point" because the duct bank (from pull boxes BPO 23, 23A, 29, 29A, 39, 39A and 20) slopes downhill toward the turbine building t
boxes BPO 13 through 20 from the point where it crosses over the circulating water discharge conduits. Therefore, water which collects in BPO 13 through 20 and SM-1 must be removed by pumping.
The Unit 2 BPO 14-20 boxes, on the other hand, are located at a relative "high-point"; eventually, some water collected in the boxes may drain through ABS conduits toward the intake structure.
Sumo Puno Reauirement and Pump Capability:
The pull boxes and outdoor portions of the DFO pipeway mainly receive sheet flow from the turbine building roof during rainstorms. DCPS C-47447 and C-48447/RPE M-7362 replaced the inroerable pumps in manholes SM-1 and SM-2 with Grundos " Boss" 300, stainless steel, 1/2 hp submersible pumps in late 1992. The rated flow range for the new pump is up to 75 GPM, with a shutoff head of 24 ft. However, because of long lengths of 1" diameter discharge pipe and high pumping head, the actual flow rate is estimated to be significantly lower. Depending on the amount and rate of rain, pumps would be expected to clear sumps and boxes of water within a period of several days.
Water in Duct Bank System:
If a pump is not functional, or water inflow exceeds pump capability, water entering pull boxes eventually could no longer drain and would enter the ABS conduits containing electrical cables, particularly those located nearer to the ,
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bottom of the boxes. Portions of the cables exposed within pull boxes could be submerged for a time.
Interroaatory 11:
Identify each occasion on which any of the cable pull box sump pumps mentioned on page 3 of 14 of LER 50-275/93-005 have been found to be inoperable, and provide copies of any reports which were generated to document these instances of ,
irioperability.
Answer to Interrocatory 11: ,
Listed below are dates since 1985 when maintenance activities were initiated related to pull box sump pumps. Activities prior to 1986 are not readily retrievable.
7/5/85 ,
9/29/85 ,
6/6/86 ,
8/10/90 7/24/91 7/24/91 2/11/92 4/30/92 PG&E is providing copies of Action Requests which document ;
these maintenance activities.
Interroaatory 12:
l Page 3 of 14 of LER 50-275/93-005 indicates that the ASW system 4kV cables are installed in duct bank conduits with .
480V power cables, 120V ac control cables, 125V de control cables, and instrument cables. Please indicate whether any of I these additional cables are associated with the ASW system and, if so, whether these additional cables have experienced j any degradation and/or f ailures. Please provide copies of any reports documenting such failures.
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. PG&E is providing a list of additional circuits associated with the ASW System. These additional circuits have not experienced failures or observable degradation.
Interroaatory 13:
Provide copies of all reports received from Okonite and/or the PG&E Testing and Ecological Services ("TES"] Laboratory concerning the 4kV ASW system cable failure which occurred on October 29, 1989, as reported in LER 50-275/005, page 4 of 14.
Answer to Interroaatory 13:
PG&E is providing the following documents related to the October 29, 1989 4kV ASW 2-2 cable failures and prepared by Okonite and/or TES.
- 1) PG&E Memo from R. Bush (TES) to D. Bauer, Dated 2/5/90, Diablo Canyon Power Plant Unit 2 Auxiliary Salt Water Pumo No. 2-2 Electrical Feeder Cable Failure Analysis.
- 2) Letter from Okonite (Bob Buente) to PG&E (R.
Bush), Dated 2/12/90, Discussing SkV shielded cable returned to Okonite from DCPP Unit 2.
- 3) PG&E Memo Ron Bush (TES) to Don Bauer, Dated 6/1/90, Diablo Canyon Power Plant Unit 2 Auxiliary Salt Water Pumo No. 2-2 Electrical Feeder Cable Failure Analysis.
- 4) Draft report from TES, Dated 5/6/93, Results of Analvtical Investications to Determine Root Causes of Medium Voltane Cable Failures at Diablo Canyon Power Plant.
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- 5) Draft (2nd) Report from TES, Dated 5/21/93, Results of Analytical Investiaations to Determine Root Causes of Medium Voltace Cable Failures at Diablo Canyon Power Plant.
Interroaatory 14:
Provide copies of all reports received from Okonite and/or the PG&E TES Laboratory concerning the 4kV ASW system cable failure which occurred on May 3, 1992, as reported in LER 50-275/93-005, page 4 of 14.
Answer to Interrocatory 14:
PG&E is providing the following documents related to the May 3, 1992 4kV Bus 14D cable failures and prepared by Okonite or TES.
- 2) Draft report from TES, Dated 5/6/93, Results of Analvtical Investiaations to Determine Root Causes of Medium voltace Cable Failures at Diablo Canyon Power Plant.
- 3) Draf t (2nd) Report from TES, Dated 5/21/93, Results of Analvtical Investications to Determine Root Causes of Medium Voltace Cable Failures at Diablo Canyon Power Plant.
Interroaatory 15:
Provide copies of all reports received from Okonite, Cable Technologies Laboratory ["CTL"), and/or the PG&E TES Laboratory or any other entity or person [s] concerning the 4kV ASW system cable failure which occurred on October 31, 1992, as reported in LER 50-275/93-005, Pages 4-5 OF 14.
Answer to Interrocatory 15:
PG&E is providing the following documents related to the October 31, 1992 4kV ASW 1-2 cable failures and prepared by various laboratories.
- 1) Cerco Analytical Lab Sheet for ASW Excavation, July 17, 1992.
- 2) TES Labs Progress report # 4, Dated 4/7/93, Analytical ;
Investications by TES to Determine Cause of 4kV and 12kV Cable Failures.
- 3) Draft report from TES, Dated 5/6/93, Results 'of Analytical Investications to Determine Root Causes of Medium .
Voltaae Cable Failures at Diablo Canyon Power Plant.
- 4) Draf t (2nd) Report from TES, Dated 5/21/93, Results of ,
Analytical Investications to Determine Root Causes of Medium Voltaae Cable Failures at Diablo Canyon Power Plant.
t Interroaatory 16:
Provide copies of any other reports concerning the 4kV ASW ,
cable failures which occurred on October 29, 1989, May 3, 1992 and October 31, 1992.
Answer to Interroaatory 16:
- 1) FAX Correspondence between Altran Laboratories (Joe Groeger) and PG&E (Wells Fargo), 5/13/93 and 5/24/93. FAX ,
contains a draft report of Altran's findings relative to the 4kV and 12kV cable failures.
- 2) Letter from Okonite (Bob Buente) to PG&E (R. Bush),
Dated 2/12/90, Discussing SkV shielded cable returned to
, Okonite from DCPP Unit 2. i i
- 3) E-Mail from V. Wyman (TES), Dated 4/1/93,
Subject:
Medium voltage Cable Failures at DCPP.
- 4) FAX Correspondence between Altran Laboratories (Joe Groeger) and PG&E (Bob Hanson), 4/7/93. FAX discusses analysis work to date.
- 5) Draft of letter from Altran to R. McDevitt, discussing Cable management program with updates to discuss recent cable '
failures, Dated 4/15/93.
- 6) Letter from Altran Labs, (Joe Groeger) to W. Fargo, Dated 4/24/93,
Subject:
Okonite Report on the root cause of the 4kV and 12kV cable Failures.
Interrogatory 17:
Provide copies of any PG&E documents which comment on the reports generated by Okonite, CTL, and/or the PG&E TES Laboratory, or any other entity or person (s) concerning the 4kV ASW system cable failures which occurred on October 29, 1989, May 3, 1992, and October 31, 1992, as reported in LER 50-275/93-005, pages 4-5 of 14.
Answer to Interroaatory 17:
The following PG&E documents are being provided that comment on reports generated by Okonite, CTL, and/or the PG&E TES Lab, or any other entity or person.
- 1) Summary of results of Chemical Analysis for 2/93 and 3/93, Dated 3/30/93.
- 2) E-Mail from W. Fargo (IPRT Chairman), Dated 5/18/93,
Subject:
TES DCPP Cable Report.
Interrogatory 18:
Describe why the DCNPP Unit 1 Bus 14D 4kV cable is considered by PG&E to be "non-safety-related" as identified in LER 50-275/93-005, page 7 of 14.
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Answer to Interroaatory 18:
The 4kV cable supplying load center transformer 14D is non- !
safety related because there are no loads connected to 480V Bus 14D necessary for safe shutdown of the plant.
Interroaatory 19:
Indicate whether PG&E believes that the 4kV ASW system cables which failed on October 29, 1989, and October 31, 1992 (as identified in LER 50-275/93-005, pages 4-5 and 7 of 14], were safety-related, and, if not, please explain in detail why not.
Answer to Interrogatory 19:
The 4kV cables for the ASW system are safety related cables. ,
Interroaatory 20:
Explain in detail the bases for PG&E's belief that the 4kV cable failures discussed in LER 50-275/93-005 were not caused by " manufacturing defects" (page 8 of 14], and provide copies of the documents which form the bases for PG&E's belief.
Answer to Interroaatory 20:
The root cause for the 4kV cable failures is still under evaluation. However, PG&E's preliminary conclusion is that i the 4kV cable f ailures are not caused by manuf acturing defects because studies of all three cable failures concluded that the ,
insulation was in good condition with no generic defects. See documents provided in Answers to Interrogatories 13-17, above.
Interroaatory 21:
Provide copies of the document [s] which describe the 4kV ASW system cable design basis for wet and/or dry conditions as ,
discussed in LER 50-275/93-005, page 8 of 14.
Answer to Interrocatory 21:
See Answer to Interrogatory 1.
Interroaatory 22:
Explain in detail the bases for PG&E's belief that 4kV cable failures discussed in LER 50-275/93-005 were not caused by
" chemical degradation" [page 8 of 14], and provide copies of the documents which form the bases for PG&E's belief.
Answer to Interrocatory 22:
There was no evidence of any chemical degradation on any of the 4kV failed cables. See Answers to Interrogatories 13-17, above.
Interroaatory 23:
Provide a copy of the root cause evaluation for the 4kV ASW system cable failures [as discussed in LER 50-275/93-005]. If the root cause evaluation is not now completed, please provide notes or drafts that have been completed. In addition, please provide a copy of the root cause evaluation when it is completed.
Answer to Interrocatory 23: ,
The root cause evaluation for the 4kV ASW system cable f ailures has not been completed. PG&E is providing the latest draft of the root cause evaluation, dated 4/8/93.
Interroaatory 24:
Describe in detail the bases for PG&E's opinion, as expressed on page 10 of 14 of LER 50-275/93-005, that "The ground detection system, as well as additional control room indication [i.e., red / green lights associated with the motors), provide sufficient time to identify and correct a problem prior to another failure causing a portion of a mutually redundant system from becoming inoperable." Please provide copies of all documents which discuss this issue and/or which form all or part of the basis for PG&E's opinion.
Answer to Interrocatory 24:
The medium voltage cables used in DCPP have 133% insulation level. Per IEEE 242 and ICEA S-66-524, cables with this insulation level can operate continuously, without damage, in the presence of a ground fault where fault isolation may be l
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accomplished within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. This one hour period is adequate to detect and isolate the ground fault. PG&E's operating procedures, in conjunction with the ground detection alarm, assure that the fault is detected immediately and well within the one hour period. .
Note, each electrical safe shutdown train (i.e. buses F, G and H) has an independent and separate ground detection system. A ground fault which occurs on the 4kV system, other than en the ASW cables, would be detected and cleared by the operators within the one hour rating of the cable. Likewise, a ground fault occurring on the operating ASW cable would be i
detected and the other ASW pump would be manually started by the operators. In the unlikely event of a ground fault resulting in a failure of the operating ASW cables prior to operator action, the circuit breaker on that circuit would trip and the control scheme for the other pump would detect that trip, through low system pressure, and automatically start the other ASW pump.
Interrogatory 25:
Provide copies of all nonconformance reports associated with 4kV cable failures in the ASW system at DCNPP, Units 1 and 2.
If some of these reports have already been provided to SLOMFP, please identify them by number and date.
Answer to Interrocatory 25:
PG&E is providing a copy of NCR D2-89-EM-N104. NCR D1-92-EM-N054 previously was provided on May 6, 1993.
Interroaatory 26:
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l Explain how the ASW system at DCNPP Units 1 and/or 2 can be operated if the 120V ac. control or instrument circuits are lost [see page 11 of 14 of LER 50-275/93-005].
Answer to Interroaatory 26:
The control power for each ASW Pump motor and valves operation is from a redundant 125V dc Class 1E system. The power supply for the annunciator is from either safety related 125V dc system or 125V dc from 480V safety related motor control center through ac/dc converter.
The de system is ungrounded, therefore grounding of either the negative or positive polarity cable will not affect the operation of the ASW system. The control circuit cable is rated 600V, and therefore a grounded 125V de cable can be operated without any time limitation. Therefore, the operator has adequate time to put the redundant ASW pump into operation and take the ASW pump with a grounded control power circuit out of operation. Besides, each motor control circuit has a white indicating light in the control room to monitor the 125V i dc potential available to the motor control circuit.
120V instrument ac power is not required for ASW system normal operation and for safe shutdown of the plant.
120V ac control power circuits from the 480-120V control transformer in the motor control center cubicles are protected by a fuse. Should a failure of any of the circuits occur due to a fault in the 120V ac circuit, the component related to that train becomes inoperable. This will not prevent the
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other train of the ASW system from performing its safety-related function or to safely shutdown the plant.
Interroaatory 27:
Please indicate whether the ASW pumps can be operated "for a limited time" with a ground on a 4kV cable, and, if so, please identify the length of time and the number of cycles of operation for which such operation is possible.
Answer to Interroaatory 27: .
As addressed in the Answer to Interrogatory 26, above, the ASW pump can be operated for one hour for most postulated ground ,
faults on its 4kV cable. Such operation is possible any number of times. However, PG&E's operating procedures assure that the fault is detected immediately and isolated. In the unlikely event of a ground fault leading to a phase-to-phase fault, the pump would trip and the redundant ASW pump would automatically start.
Interrocatory 28:
At page 10 of LER 50-275/93-005, PG&E states that "In all cases, DCPP has ground detection alarms that provide indication that a potential cable problem exists." Please indicate whether there are any safety-related electrical power, control, or instrumentation cables which are not equipped with round detection alarms, and, if so, please identify the affected components and trains of systems.
Answer to Interrocatory 28:
Of the safety-related electrical power, control and instrumentation cables associated with the ASW system, only the 120V ac control power circuits from the 480-120V cable transformer in the motor control center cubicles do not have a ground detection alarm. However, these circuits are l
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protected by a fuse should a failure occur. See Answer to Interrogatory 26, above.
Interrocatory 29:
At page 10 of LER 50-275/93-005, PG&E states that "The 12kV, 4kV, and 480V systems have high-resistance grounding, which allows continued operation for a limited time in the event of a single-line-to-ground fault." Please quantify, for each type of cable, what is meant by " limited time." In each case, what is the longest time that the cable would need to operate during an accident? Please describe the basis for your answer.
Answer to Interrocatory 29:
The cables of each of 12kV, 4kV and 480V Systems can be operated for one hour before isolation of the ground fault, as per the standards identified in the response to Interrogatory
- 26. This time is adequate to put into operation the redundant i
ASW train for safe shutdown of the plant.
r There is no safety-related application of 12kV cables'. l Therefore, 12kV cables are not necessary to safely shutdown the plant.
Each 4kV safety-related cable application and each 480V safety-related bus has independent and separate ground ,
detection system.
i Interroaatory 30:
Identify all other safety-related applications of the 4kV l cable that is described in LER 50-275/93-005.
a) Are the cables in these applications submerged at any l time? If so, please describe any and all steps that have been taken to verify their operability. !
I b] Are any of these safety-related applications of 4kV cable subject to the requirements of 10 CFR 50.49 due to their location in a harsh accident environment? If so, please describe all steps that have been taken to determine whether
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the environment in which they have been installed' (i.e.,.
temperature, radiation, humidity), is within the bounds of the-conditions to which the cable was aged for purposes of environmental- qualification, or which were. assumed for purposes of environmental qualification. Please supply copies o# all records compiled in making this determination. .
l c) For all such cable located in a harsh environment, please discuss whether ground detection alarms are used. If so, please discuss the extent to which they would be effective in predicting cable failure in the event of a LOCA.
Answer to Interroaatorv 30:
The other safety-related applications for the 4kV cables are ,
for the following:
- 1. Auxiliary Feedwater Pumps 12, 13 (U1); 22, 23 (U2) 1
- 2. Component Cooling Water Pumps'11, 12, 13 (U1); 21, 22, 23 (U2)
- 3. Centrifugal Charging Pumps 11, 12 (U1); 21, 22 (U2)
- 4. Safety Injection Pumps 11, 12 (U1); 21, 22 (U2)
- 5. Containment Spray Pumps 11, 12 (U1); 21, 22 (U2) ,
- 6. Residual Heat Removal Pumps 11,12 (U1) ; 21, 22 (U2)
- 7. Load Center transformers IF,1G, 1H (U1) ; 2F, 2G, 2H (U2) ,
- 8. D/G 11, 12, 13 (Unit 1); 21, 22, 23 (Unit 2).
a) The 4kV feeder cables to the above safety-related loads are installed in indoor raceways and/or in~ '
underground ductbanks embedded in concrete with all pull-boxes located indoors. These cables are not submerged during normal plant operation.
b) PG&E objects to this request because it is related .l to the environmental qualification of equipment, i
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not to maintenance issues within the scope of Contention I as admitted.
c) PG&E objects to this request for the same reason cited in Answer to Interrogatory 30(b), above.
Interrogatory 31:
Identify all other safety-related applications of the 12kV cable that is described in LER 50-275/93-005.
a] Are the cables in these applications submerged at any time? If so, please describe any and all steps that have been taken to verify their operability.
b] Are any of these safety-related applications of 12kV cable subject to the requirements of 10 CFR 50.49 due to their location in a harsh accident environment? If so, please describe all steps that have been taken to determine whether the environment in which they have been installed (i.e.,
temperature, radiation, humidity], is within the bounds of the conditions to which the cable was aged for purposes of environmental qualification, or which were assumed for purposes of environmental qualification. Please supply copies of all records compiled in making this determination.
c) For all such cable located in a harsh environment, please discuss whether ground detection alarms are used. If so, please discuss the extent to which they would be effective
'in predicting cable failure in the event of a LOCA.
Answer to Interroaatory 31:
There are no safety-related applications of the 12kV cables at DCPP.
Interroaatory 32:
In NRC Information Notice No. 89-30 [ March 15, 1989], the NRC alerted licensees to " potential problems resulting from high temperature environments in areas that contain safety-related equipment or electrical cables." & at 1 [ copy attached].
The NRC noted that "It is important for licensees to be aware that there are areas within the plant where the local temperature may exceed equipment qualification specifications even when the bulk temperature, as measured by a limited number of sensors, is indicating that it is lower than the qualification temperature." & at 3. SLOMFP seeks to determine, for any safety-related applications of 4kV cable or
12kV cable in a harsh environment, whether PG&E measures local temperature with reasonable accuracy. Please describe PG&E's method for measuring the temperature to which safety-related cable is subjected. Into what zones, if any, is the containment broken for purposes of temperature measurement?
Please provide the results of all such temperature measurements. Please provide the results of any comparisons i
between these temperature measurements and environmental qualification specifications for cable.
Answer to Interrocatory 32:
Maintenance Procedure MP E-57.4 establishes PG&E's program for temperature monitoring in connection with maintenance of environmentally-qualified equipment, including cables.
Results from such temperature monitoring are available for inspection at DCPP.
Interrocatory 33:
Please provide copies of any documents which describe PG&E's evaluation of or response to NRC Information Notice 89-30
["High Temperature Environments at Nuclear Power Plants",
March 15, 1989).
Answer to Interroaatory 33:
PG&E is providing a copy of its June 14, 1989 review of IE Notice 89-30.
i Interrogatory 34: ;
l At page 4 of 14 of LER 50-275/93-005, PG&E states that the l testing laboratories " determined the [ October 29, 1989] l f ailure to be an isolated event." Please explain whether PG&E now agrees with these assessments, and provide the basis for l PG&E's current beliefs and conclusions in this regard. l l
Answer to Interrocatory 34: )
l PG&E's preliminary conclusion is that the 4kV cable failures are not generic in nature, and that laboratory investigations after each failure support this position. This is based upon substantial laboratory review , and discussions with the cable manufacturer.
Interroaatorv 35:
In LER 50-275/93-005 [page 11 of 14), PG&E stated that, "Furthermore, since the failures have been separated in time, and diagnostic examinations of the failed cables and the additional 'non-failed' cables show no evidence that i
additional failures are imminent, the probability of a design basis accident followed by a random 4kV failure is considered to be very low." Did the laboratory and visual examinations of the " failed" and anon-failed" cables show any differences?
If so, please describe the differences in detail. If not, please explain how PG&E can reach the conclusion quoted above.
Moreover, please explain in quantitative terms what PG&E means '
by "very low" in the context of the probability of a design '
basis accident followed by a random 4kV cable failure.
Answer to Interroaatory 35:
As discussed above, the root cause is still under evaluation for the 4kV cable failures which have occurred. However, PG&E's preliminary conclusion is that additional failures are i not imminent, because diagnostic examination of failed cables indicates no generic degradation or failure mechanism. In addition, the failures have been separated in time. This preliminary conclusion is not based on any finding of differences between failed and nonfailed cables.
PG&E has evaluated the impact of the failures of the ASW safety related 4kV cables on the Diablo Canyon core damage frequency (CDF) by updating the ASW system failure probabilities. These failure probabilities were increased to reflect an increase in the random failure probability of a single ASW pump due to an additional two pump failures i occurring within the total operating period of DCPP. While i
the random failure probability of a single ASW pump increased over 100% (based on adding two additional failures), the impact on CDF was determined to be insignificant.
Notwithstanding that no clear, imminent failure mechanism has been identified which caused the cable failures, the probability of additional cable failures is assumed to be very low. Furthermore, the impact on CDF of the 4kV cable failures (assumed to cause ASW pump failures) which did occur is very small since the redundant train would still be available for accident mitigation.
Interroaatory 36:
Provide copies of the documents which describe the " formal preventive maintenance program" which has been established for the " sump pumps and drains immediately outside the turbine building" [LER 50-275/93-005, page 11 of 14].
Answer to Interrogatory 36:
PG&E is providing AR A0304814, R0118283, and RO118288, which include the pull box sump pumps and drains as recurring task activities in PG&E's formal preventive maintenance program.
Interrocatory 37:
In LER 50-275/93-005 [page 8 of 14], PG&E indicates that it made inquiries of other nuclear power plants regarding medium voltage EPR insulated cable failures. Please provide copies of documents which describe the substance of those inquiries, or, if no such documents are available, please identify whether any other failures have occurred and, if so, please describe the circumstances [ type of cable, system affected, plant name, date, method of discovery of the failure, and the assessed root cause for the failure).
Answer to Interrocatory 37:
PG&E is providing a summary of its informal survey of other nuclear power plants regarding cable failures. Since the i
--r
information provided is confidential, the names of the plants are not being provided.
Respectfully submitted, Joseph B. Knotts, Jr.
David A. Repka Kathryn M. Kalowsky WINSTON & STRAWN 1400 L Street, N.W.
Washington, DC 20005-3502 (202) 371-5726
- f. u ' 'A Christophet J. Kgrner kQ i Richard F. Locke PACIFIC GAS AND ELECTRIC COMPANY 77 Beale Street San Francisco, CA 94106 Attorneys for Pacific Gas and Electric Company Dated in San Francisco, CA this 28th day of May, 1993
.- l l
ATTACHMENT 1 l i
SECOND SET OF SUPPLEMENTAL INTERROGATORIES AND REQUESTS FOR PRODUCTION OF DOCUMENTS RE: CABLE FAILURES AT DIABLO CANYON NUCLEAR POWER PLANT l
- 1. Specification No. 0702 dated July 15, 1971
- 2. Entry "
Subject:
Electrical Okonite Cable Failures, Failure Mechanism, Root Cause 9-1-92"
- 3. Entry "
Subject:
Auxiliary Saltwater Pump Motor Power Cable Failed Hi-pot Testing, January, 1993"
- 4. Entry "
Subject:
Additional Power Cable Fault to Ground, February, 1993"
- 5. MP E-17.1
- 6. MP E-54.2 1
- 7. STP P-7A
- 8. STP P-7B
- 9. Various Circuit Installation and Termination Inspection Records
--Construction Documentation: Circuit G06H00 Circuit Installation Record, 12/11/75 Termination Inspection Report, 12/15/75
--Construction Documentation, Circuit F08H00 Circuit Installation Record, 12/11/75 Termination Inspection Report, 12/15/75
--Construction Documentation, Circuit G06H00 Circuit Installation Record, S/31/74
--Construction Documentation, Circuit F08H00 Circuit Installation Record, 2/8/74
--Construction Documentation AR A0283650 and various work orders Work Orders C0063056-01, C00106431-01, C0112307-02
- 10. Various QC Surveillance and Inspection Reports QCS 93-0016, 92-0085 QCI 92-1688, 92-1687, 92-0446, 91-1237, 89-1774, 88-1863, 88-1862, 88-0330, 88-0176 ARs A0284076, A0284173, A0300220
- 11. ARs A0000818, A0007706, A0026569, A0200329, A0237275, A0237284, A0258320, A0264973 1 '
- 12. List of Additional Circuits Associated with ASW System
- 13. PG&E Memo from R. Bush (TES) to D. Bauer, Dated 2/5/90, Diablo Canyon Power Plant Unit 2 Auxiliary Salt Water Pump No. 2-2 Electrical Feeder Cable Failure Analysis.
- 14. Letter from Okonite (Bob Buente) to PG&E (R. Bush), Dated 2/12/90, Discussing SkV shielded cable returned to Okonite from DCPP Unit 2.
- 15. PG&E Memo Ron Bush (TES) to Don Bauer, Dated 6/1/90, Diablo Canyon Power Plant Unit 2 Auxiliary Salt Water Pumo No. 2-2 Electrical Feeder Cable Failure Analysis.
- 16. Draft report from TES, Dated 5/6/93, Results of Analytiqql Investications to Determine Root Causes of Medium Voltaae Cable Failures at Diablo Canyon Power Plant.
- 17. Draft (2nd) Report from TES, Dated 5/21/93, Besults of Analvtical Investigations to Determine Root Causes of Medium Voltace Cable Failures at Diablo Canyon Power Plant,
- 19. Cerco Analytical Lab Sheet for ASW Excavation, July 17, 1992
- 20. TES Labs Progress report #4, dated 4/7/93, Analvtical Investications by TES to Determine Cause of 4kV and 12kV Cable Failures
- 21. FAX Correspondence between Altran Laboratories (Joe Groeger)
,and PG&E (Wells Fargo), 5/13/93 and 5/24/93. FAX contains a draf t report of Altran's findings relative to the 4kV and 12kV cable failures.
- 22. E-Mail from V. Wyman (TES), Dated 4/1/93,
Subject:
Medium voltage Cable Failures at DCPP.
- 23. FAX Correspondence between Altran Laboratories (Joe Groeger) and PG&E (Bob Hanson), 4/7/93. FAX discusses analysis work to date.
- 24. Draft of letter from Altran to R. McDevitt, discussing Cable management program with updates to discuss recent cable failures, Dated 4/15/93.
- 25. Letter from Altran Labs, (Joe Groeger) to W. Fargo, Dated 4/24/93,
Subject:
Okonite Report on the root cause of the 4kV and 12kV cable Failures.
- 26. Summary of Results of Chemical Analysis for 2/93 and 3/93, dated 3/30/93.
2
- 27. E-mail from W. Fargo, dated 5/18/93,
Subject:
TES DCPP Cable Report
- 28. Draft Root Cause Evaluation, dated 4/8/93
- 29. NCR D2-89-EM-N104
- 30. Memorandum, June 14, 1989, Review of IE Notice No. 89-30 t
- 31. AR A0304814; R0118283, R0118288
- 32. Survey of Nuclear Power Plants Re: Cable Failures i
3
- . _ . .- . - . ~ . -
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION i BEFORE THE ATOMIC SAFETY AND LICENSING BOARD t
In the Matter of: ) !
) Docket Nos. 50-275-OLA l Pacific Gas and Electric Company ) 50-323-OLA [
) (Construction Period ;
(Diablo Canyon Nuclear Power Recovery)
)
Plant, Units I and 2) ) .;
I
)
I, James E. Molden, being duly sworn, hereby state as follows. f
- 1. I am employed by Pacific Gas and Electric Company as Director, Instrumentation !
and Controls.
l
- 2. My business address and phone number are: ;
Diablo Canyon Power Plant 104/5/521 P. O. Box 56 Avila Beach, CA 93424 I
(805) 545-4336
- 3. I have provided the information which forms the basis for the answers to [
Interrogatories I through 37 included in the attached " Pacific Gas and Electric .'
Company's Response to Second Set of Supplemental Interrogatories and Requests for the Production of. Documents (Cable Failures) Filed by San Luis Obispo !
Mothers for Peace." i
- 4. The information contained in the referenced interrogatory answers and responses to requests for documents is true and correct to the best of my knowledge and belief. ;
Segrrof G4 fro.c @
hE James E. Molden i Co swry /f e3Ad lui.r 66 )C Pb ,
Sworn and subscribed to before me this 27th day of May, 1993 s E EINnYL Notary Public m gg-c ;
, e ** c o mm Empres Jul 18.1995 ,
My commissior(expires:
UNITED S1ATES OF AMERICA NUCLEAR REGULATORY COMMISSION 4
BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of: )
) Docket Nos. 50-275-OLA Pacific Gas and Electric Company ) 50-323-OLA
) (Construction Period ,
(Diablo Canyon Nuclear Power ) Recovery)
Plant, Units 1 and 2) )
) ;
AFFIDAVIT I, Steve R. Ortore being duly sworn, hereby state as follows.
- 1. I am employed by Pacific Gas and Electric Company as Director, Electrical Maintenance.
- 2. My business address and phone number are:
Diablo Canyon Power Plant 104/5/523 P. O. Box 56 Avila Beach, CA 93424 (805) 545-4175
- 3. I have provided the information which forms the basis for the answers to Interrogatories 1 through 37 included in the attached " Pacific Gas and Electric Company's Response to Second Set of Supplemental Interrogatories and Requests for the Production of Documents (Cable Failures) Filed by San Luis Obispo Mothers for Peace."
- 4. The information contained in the referenced interrogatory answers and responses to requests for documents is true and correct to the best of my knowledge and belief.
e .
eSrArc of Cs (ke ALv' 6 veh R. Ortore CetwryoiG.a L A.s DAisPo Sworn and subscribed to before me this 27th day of May, 1993 Notary Public (j' ,
^^^^^ ^^^d'{^]^^^{^^[,
SANDRA EATHERLY q Notry Putsc-Cmkms , ,
SAN LUIS 08 spo COUNTY 7/j ,,_
4 w
44 h Egens JUL 18,1995 ,
My cosnission expires:
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of: )
) Docket Nos. 50-275-OLA
) 50-323-OLA Pacific Gas and Electric Company ) (Construction Period
) Recovery)
(Diablo Canyon Nuclear Power )
Plant, Unites 1 and 2) )
)
AFFIDAVIT I, Tom F. Fetterman, being duly sworn, hereby state as follows.
- 1. I am employed by Pacific Gas and Electric Company as Electrical Engineering Supervisor.
- 2. My business address and phone number are:
Pacific Gas & Electric Company 333 Market Street, Room A9042 San Francisco, CA 94105 (415) 973-5044
- 3. I have provided the information which forms the basis for the supplemental answers to Interrogatories 3, 4, 7-9, 13-31, 34, 35 and 37 included in the attached " Pacific Gas and Electric Company's Supplemental Response to Second Set of Supplemental Interrogatories and Requests for Production of Documents Re:
Cable Failures at Diablo Canyon Nuclear Power Plant Filed by San Luis Obispo Mothers for Peace."
- 4. The information contained in the referenced interrogatory answers and responses to requests for documents is true and correct to the best of my knowledge and belief.
IH1 . h Tom F. Fetterman Sworn and subscribed to before me this 39 0 day of May, 1993 , gg, , ,,,, ,
M 6 l AMY EMIK0 DONG reur euanc.cAuFouhiA E l
Notary)Public / '
CITY & COUNTY OF SAN FRANCISCO)
My Commission Expres Dec. 23,1994 l nuuuuuutuusmaumumuuluulumnin:lttlittuutukitubulinnillil My commission expires
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of: )
) Docket Nos. 50-275-OLA Pacific Gas and Electric Company ) 50-323-OLA
) (Construction Period (Diablo Canyon Nuclear Power ) Recovery)
Plant, Units 1 and 2) )
)
AFFIDAVIT I, Richard D. Cramins, being duly sworn, hereby state as follows.
- 1. I am employed by Pacific Gas and Electric Company as a Senior Quality control Specialist.
- 2. My business address and phone number are:
Diablo Canyon Power Plant 104/3/4B P. O. Box 56 Avila Beach, CA 93424 (805) 545-4209
- 3. I have provided the information which forms the basis for the answer to Interrogatory 6 included in the attached " Pacific Gas and Electric Company's Response to Second Set of Supplemental Interrogatories and Requests for the Production of Documents (Cable Failures) Filed by San Luis Obispo Mothers for Peace."
- 4. The information contained in the referenced interrogatory answers and responses to requests for documents is true and correct to the best of my knowledge and belief.
[ .
Yg J q -
M rc or (A / roe de4 f
dichard D'. Cramins C's oury e F &A) L tOS AA/3Pb Sworn and subscribed to before me this 27th day of May, 1993 ome f Notary Public ff < hary m-camen I
SAN Lut$ omSPo COUNTY
< W h Exatas At is,iaM '
y g [
........,l My c'ommission expires:
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of: )
) Docket Nos. 50-275-OLA Pacific Gas and Electric Company ) 50-323-OLA
) (Construction Period !
(Diablo Canyon Nuclear Power ) Recovery)
Plant, Units 1 and 2) )
)
AFFIDAVIT I, James A. Davis, being duly sworn, hereby state as follows.
- 1. I am employed by Pacific Gas and Electric Company as Senior Supervisor, Quality Assurance.
- 2. My business address and phone number are:
1 California Street, Room F1820 San Francisco, CA 94111 (415) 973-3249
- 3. I have provided the information which forms the basis for the answer to Interrogatory 6 included in the attached " Pacific Gas and Electric Company's Response to Second Set of Supplemental Interrogatories and Requests for the Production of Documents (Cable Failures) Filed by San Luis Obispo Mothers for Peace."
- 4. The information contained in the referenced interrogatory answers and responses to requests for documents is true and correct to the best of my knowledge and belief.
~
i OFFiCAL SEAL M '" BIANCA E. ZELNIK b
'o - : NOTARY PUBUC - CAUFORNIA ( g i 7
- San Francisco County d - -.
,es A. Davis L J ur coussen h:ms J4 m ms j a __ _ _ ,_ -m _ _ _=_ ,_~
Sworn and subscribed to before me this 25th day of May, 1993
[.[ Lbit '
No ary Public
^
L J. .X l'} '16 My commission expires:
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of: )
) Docket Nos. 50-275-OLA Pacific Gas and Electric Company ) 50-323-OLA
) (Construction Period (Diablo Canyon Nuclear Power ) Recovery)
Plant, Units 1 and 2) )
)
AFFIDAVIT I, Steven W. Hamilton, being duly sworn, hereby state as follows.
- 1. I am employed by Pacific Gas and Electric Company as a Senior Nuclear Generation Engineer, Operating Experience Assessment.
- 2. My business address and phone number are:
77 Beale Street, Room 1465 San Francisco, CA 94105 (415) 973-8101
- 3. I have provided the information which forms the basis for the answer to Interrogatory 33 included in the attached " Pacific Gas and Electric Company's Response to Second Set of Supplemental Interrogatories and Requests for the Production of Documents (Cable Failures) Filed by San Luis Obispo Mothers for Peace."
- 4. The information contained in the referenced interrogatory answers and responses to requests for documents is true and correct to the best of my knowledge and belief.
WT "SttNen Wi'14aiftilton ~
Sworn and subscribed to before me this 28th day of May, 1993 pimmtim11mummsntmuunmuntuntummmnmimmmmumfl g, OFHCIAL StAL lb g -
AMY EMIKO DONG q Notarj' Public / l' NOTARY Pl>BLIC CAlfF0WA i city & coum1r Dr SAN FRANCl$ 0]
5 'dv comm'$5'oa t=n',.. oec. 23.1994 k/R V I ' '
Wuunmituumsmmmunummmnm1ammmmtmmumm!3.y J My commission exp' ires:
n R LATEDCORpggpgggggy
. UNITED STATES OF AMERICA _
NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOA D E ~1 T:07 In the Matter of: ) .
) Docket Nos. 50-275-OLA Pacific Gas and Electric Company ) 50-323-OLA
) (Construction Period (Diablo Canyon Power ) Recapture)
Plant, Units 1 and 2) )
)
CERTIFICATE OF SERVICE I hereby certify that copies of " PACIFIC GAS AND ELECTRIC COMPANY'S RESPONSE TO SECOND SET OF SUPPLEMENTAL INTERROGATORIES AND REQUESTS FOR PRODUCTION OF DOCUMENTS RE: CABLE FAILURES AT DIABLO CANYON NUCLEAR POWER PLANT FILED BY SAN LUIS OBISPO MOTHERS FOR PEACE" in the above-captioned proceeding have been served on the following by deposit in the United States mail, first class, or as indicated by an asterisk
(*) , by Federal Express overnight delivery, this 28th day of May,1993.
Copies of documents being provided, as referenced in the discovery response, are being provided only to parties indicated by the (t) symbol.
Charles Bechhoefer, Chairman Frederick J. Shon .
Administrative Judge Administrative Judge j Atomic Safety and Licensing Board Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 Washington, DC 20555 Jerry R. Kline Office of Commission Appellate Administrative Judge Adjudication Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission j U.S. Nuclear Regulatory Commission Washington, DC 20555 ,
Washington, DC 20555 )
Office of the Secretary Ann P. Hodgdon, Esq.(t) l U.S. Nuclear Regulatory Commission Office of the General Counsel I Washington, DC 20555 U.S. Nuclear Regulatory Commission l Attn: Docketing and Service Washington, DC 20555 i Section (original + two copies) l Adjudicatory File Peter Arth, Jr.
Atomic Safety and Licensing Edward W. O'Neill Board Panel Peter G. Fairchild U.S. Nuclear Regulatory Commission California Public Utilities ,
Commission Washington, DC 20555 505 Van Ness Avenue San Francisco, CA 94102 l
j 1
Nancy Culver, President Truman Burns Board of Directors California Public Utilities San Luis Obispo Mothers for Peace Commission P.O. Box 164 505 Van Ness, Rm. 4103 Pismo Beach, CA 93448 San Francisco, CA 94102 Robert R. Wellington, Esq. Joseph B. Knotts, Jr., Esq. '
Diablo Canyon Independent Safety David A. Repka, Esq.
Committee Winston & Strawn 857 Cass Street, Suite D 1400 L Street, N.W.
Monterey, CA 93940 Washington, DC 20005-3502 Robert Kinosian Jill ZamEk*(+)
California Public Utilities 1123 Flora Road Commission Arroyo Grande, CA 93420 505 Van Ness, Rm. 4102 San Francisco, CA 94102 Mr. Gregory Minor
- MHB Technical Associates 1723 Hamilton Ave., Suite K San Jose, CA 95125 b f Christophet J.
&O y'tner p
Counsel for Pacific Gas and Electric Company
!