IR 05000275/1985037
| ML17083B669 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/14/1985 |
| From: | Ivey K, Phelan P, Thomas Young NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML17083B668 | List: |
| References | |
| 50-275-85-37, 50-323-85-35, GL-83-28, GL-85-06, GL-85-6, NUDOCS 8512100507 | |
| Download: ML17083B669 (20) | |
Text
Report Nos
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Docket Nos.
U.
S.. NUCLEAR,IKGULATORY COMMISSION j
REGION V
50-275/85-37, 50-323/85-35 50-275 and 50-323 License Nos.
I Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Facility Name:
Inspection at:
Inspection conducted:
Diablo Canyon - Units 1 and
San Luis Obispo County, California October 21-25, 1985 Inspectors:
Ivey e
nsp c o Da e igned P.
.
helan, Reactor Inspector Consultants:
P.
Chan, Engineer, LLNL W.
W de, Engineer, EGSG Dat Signed Approved By:
T. Young, Jr.,
Ch f, Engi r
g Section Date Signed
~summar Ins ection durin the eriod October 21-25 1985 (Re ort Nos. 50-275/85-37 and 50-323/85-35)
Areas Ins ected:
An unannounced, safety inspection by two NRC regional based inspectors and two NRC consultants for the follow-up of Generic Letter 83-28
"Required Actions Based on Generic Implications of Salem ATWS Events",
TI 2515/64 Rev.
1 "Near-Term Inspection Follow-up to Generic Letter 83-28",
"QA Guidance For ATWS Equipment that Is Not Safety-Related."
The inspection involved 69 hours7.986111e-4 days <br />0.0192 hours <br />1.140873e-4 weeks <br />2.62545e-5 months <br /> by two NRC inspectors and 69 hours7.986111e-4 days <br />0.0192 hours <br />1.140873e-4 weeks <br />2.62545e-5 months <br /> by two NRC consultants on Module Nos.
30703, 92704B, and 25564B.
Results:
No violations or deviations were identified.
8512100507 851118 I
PDR ADOCK 05000275
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1.
. Persons, Contacted
"-R. C. Thornberry, Plant Mana'ger
='W: B: Kaefer, Assistant Plant Manager/Support Services
>>J.
M. Gisclon, Assi.'slant Plant Manager/Technical Services
"T. X.',Grebel, Regulatory, Compliance Supervisor L. F."Womack, Engineering 'Manager
<<D. Miklush, Maintenance Manager
"S. R. Fridley, Operations Manager
>"J. Boots, Chemistry and Radiation Protection Manager S. Foat, Power Production Engineer, Maintenance
-"W. G. Crockett, ISC'Maintenance Manager
='Denotes those attending the exit meeting on October 25, 1985 (The Senior Resident Inspector and Resident Inspectors were also present at the exit meeting).
2.
~Back round In February 1983, during startup of the Salem Nuclear Power Station Unit 1, the Westinghouse Type DB-50 reactor trip system (RTS) circuit breakers twice failed to open automatically upon receipt of a valid trip signal.
The failure to trip was attributed to a binding within the undervoltage trip attachment (UVTA) located inside the breaker cubicle.
Due to the failures at Salem and similar failures at other plants, and as a result of its investigations and reviews of the failures, the NRC Office of Nuclear Reactor Regulation issued Generic Letter (GL) 83-28 to all licensees and applicants on July 8, 1983.
This letter required all affected utilities to furnish the status of current conformance to the Generic Letter and their plans and schedules for any needed improvements.
Four of the items in GL 83-28 are identified for Region-Based post-implementation review.
They are:
item 3.1 Post-Maintenance Testing (Reactor Trip System Components)
Item 3.2 Post-Maintenance Testing (All Other Safety-.Related Components)
The inspection is to address the adequacy and completeness of the Post-Maintenance Testing (including modifications) of safety-related components.
Item 4.1 Reactor Trip System Reliability (Vendor Related Modifications)
Item 4.5.1 Reactor Trip System Reliability (System Functional Testing)
The inspection is to ensure that. vendor-recommended modifications and RTS changes are completed in PWRs and that on-line functional testing of the RTS diverse trip features is performed on all LWR I I
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On February 2, 1984, the NRC Office of Inspection and Enforcement issued Temporary Instruction (TI) 2515/64,
"Near-Term Inspection Follow-up to Generic Letter 83-28", for Region-Based inspection to identify immediate licensee actions to various items in GL 83-28 and associated licensee programs that were in place.
Revision 1. to the TI was subsequently issued April 4, 1985.
Items from the TI to be inspected by the regions are identified as follows:
Equipment Classification (Response to Items 2.1 and 2.2.1 of GL 83-28)
Vendor Interface (Response to Items 2.1 and 2.2.2 of GL 83-28)
Post Maintenance Testing (Response to Items 3.1 and 3.2 of GL 83-28)
RTS Reliability (Response to Items 4.2 and 4.5.1 of GL 83-28)
3.
General 4.
The licensee's initial response to GL 83-28 was submitted by letter on November 7, 1983.
(I Diablo Canyon Units 1 and 2 utilize the Westinghouse RTS Design and
,Westinghouse DB-50 reactor trip breakers (RTBs).
This design consists of two RTBs'nd two bypass breakers to facilitate testing.
The RTS uses
'ensors which monitor various plant parameters to feed analog circuitry copsisti'ng'oftwo to four redundant channels.
The RTS also contains the digital"logic circuitry necessa'ry,,to automatically open the RTBs.
The digital circuitry. 'consists of two redundant logic trains which receive inputs <<from the analog protection channels.
Each of the two trains is capable of opening a.separate and independent RTB to scram the plant (i.e.", remove power from'he,rod drive power supply and release the control rods: into the core by gravity).
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p The RTB's, utilize both an undervoltage trip attachment (UVTA) and a shunt trip'evice.
Autom'atic actuation of the shunt trip was added in response to GL 83-28.
A trip signal (manua1 or automatic) interrupts power to the UVTA and simultaneously applies power to the shunt trip device.
During a loss of power or low voltage condition, the UVTAs would trip the breakers to scram the plant.
Item 3.1 Post-Maintenance Testin (RTS Com onents)
GL 83-28 Re uirements:
Item 3.1.1 Licensees and applicants shall submit the results of their review of test and maintenance procedures and Technical Specifications to assure that post-maintenance operability testing of safety-related Components in the RTS is required to be conducted and that the testing demonstrates that the equipment is capable of performing
'ts safety functions before being returned to servic U
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Item 3.1.2 Licensees and applicants shall submit the resul'ts of their check of vendor and engineering recommendations to ensure that any appropriate test guidance is included in the test and maintenance procedures or the Technical Specifications where required.
F~indin n:
The inspectors reviewed the results of the review of test and maintenance procedures and concluded that the licensee has met the requirements for item 3.1.1.
Nuclear Plant Administrative Procedure (NPAP) C-6,
"Clearances",
requires the performance of tests before returning a system or component to an operable status.
Administrative Procedure (AP) C-653,
"Post-Maintenance Testing", requires that appropriate post-maintenance testing be determined at the time the clearance request for maintenance is made.
The shift foreman, or his delegate, is responsible for properly implementing these procedures.
Documentation is provided on the clearance request form, which must include the selected post-maintenance tests when it~,is submitted for the shift, foreman's approval.
These procedures 'provide requirements to ensure that equipment is tested and operational prior to being returned to service.
The inspectors reviewed the licensee's incorporation of vendor and engineering. recommendations't'o
'ensure that, appropriate test guidance is
, included in, maintenance procedures on RTS components.
Specifically, the inspectors reve.ewed the licensee's maintenance procedures on the RTBs to verify incorporation of Westinghouse maintenance recommendations.
The licensee incorporates the Westingh'ouse information into their RTB maintenance.,',
The inspectors concluded that the'icensee has met the requirements of'tem 3.1.2.
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'he inspectors observed a demonstration of the RTB preventive maintenance procedure (MP,,E-51.7 "Mainten'ance of Westinghouse Type DB, 480 Volt Circuit Breakers" ). and noted that the licensee's maintenance personnel were'nowledgeable in; the -performance of the procedure.
The inspectors
'noted one conce'rn with th'e us'e"of non-standard feeler gauges to determine RTB clear'ances.
Three of the"gauges (0.050 inch, 1/32 inch, and 1/8 inch) were composed'of several-, pieces of bar stock material taped together with their composite dimension hand-written on t;he tape.
Recent failures of RTBs due to inadequate clearances have proven the importance of ensuring that clearance measurements are taken correctly. If one of the pieces of bar stock material were to become separated from the others, the composite dimension would be changed and the possibility would exist to allow RTB clearances to be out of specification.
At the exit meeting, the licensee committed to review this concern.
The inspectors reviewed the preventive maintenance test data for all RTBs in the May/June, 1985, time frame.
These data were trended (along with previously taken data) in accordance with MP E-51.7B, "Reactor Trip/Bypass Breaker Performance Trending".
The inspectors noted that the data trended to date have been satisfactory.
No violations or deviations were identifie t
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Item 3.2 Post.-Maintenance Testin (All Other Safet -Related Com onents)
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GL 83-28 Re uirements:
Item 3.2.1 licensees and applicants shall submit a report documenting the extending of test and maintenance procedures and Technical Specifications review to assure 4P that post-maintenance operability testing of all safety-related equipment is required to be conducted and that, the testing demonstrates that the equipment is capable of performing its safety functions before being returned to service.
Item 3.2.2 Licensees and applicants shall also submit the results of their check of vendor and engineering recommendations to ensure that any appropriate test guidance is included in the te0t and, maintenance procedures or the Technical Specifications where'e'quired.
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F~indin n The reviews required by thi's itemdare still in progress and scheduled for completion by December 1, 1985, for Unit 1 and August 1, 1986, for Uni.t 2.
Consequently, Item 3.2 will remain an open item for a future NRC inspection (50-275/85-'37-01)'.,
II C
Post-mp'intenance testing is performed on all safety-related components as detailed in paragraph 8 sub-section c, "Post-Maintenance Testing".
The inspectors'eviewed completed maintenance documentation, and observed parts of preventive maintenance and post-maintenance testing conducted for regularly scheduled activities.
The inspectors verified that the work and post-maintenance tests were 'being performed in accordance with procedures, and personnel were qualified and knowledgeable to do the'ork..
The work packages examined were as follows:
Preventive Maintenance Action Request AOOO 8495 on Auxiliary Feed Water Pump 1-2.
The inspectors noted that the work package included all the associated maintenance procedures and the pump was clearly identified as safety-related
"Q" Class I.
The inspectors verified that the associated high voltage switchgear was properly de-energized and tagged, and observed part of the maintenance calibration on relays.
Preventive Maintenance per IRI-2E-53.9 on motor operated RHR Suction Valve-2, hot leg loop 4, Unit 2 (non-safety related).
Packing adjustment for motor operated valve (Clearance Request g915114-85)
SI-2-88-8B, surveillance tests per STP M-45 and STP V-314 for post-maintenance test (safety-related).
Preventive maintenance (Clearance Request
$I3-1474-85) per maintenance procedure MP E-53.9 on motor operated valve FCV-440
'ost-maintenance test per surveillance test Procedure STP V-2U, V-3P2 (safety-related).
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n Preventive maintenance (Clearance Request fjl2-3606-85) per PM activity-7/51739, 46126, 46127,,on containment spray pump CSP 1-1.
Post-maintenance test per surveillance test procedure STP P-4B (safety-,related).
, No violations or deviations', were identified.
I Item 4.1 RTS Reliabilit '(Vendor Related Modifications)
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s GL 83-28 Re uirement:
All vendor-recommended RTB modifications shall be reviewed to verify that either.:
(1) each modificator.on has been implemented; or (2)
a written evaluation of the technica1 reasons for not implementing a modification exists.
P~indin s:
Xn satisfying the requirements of GL 83-28, the licensee stated that all vendor related modifications have been fully reviewed and implemented.
The latest vendor-issued bulletins were reviewed to verify that all recommendations were being addressed.
The only required modification was the addition of automatic actuation of the RTB shunt trip attachment.
The shunt trip would then serve as a back-up to the UVTA in the event of a low voltage or loss of power condition.
The licensee interfaced with the Westinghouse Owners Group (WOG) in developing the design criteria, pre-implementation and installation review.
A11 work associated with this modification is complete.
Also, a trip counter was installed on the RTB to accurately record the number of breaker trips.
PGSZ Maintenance Procedure MP-E-51.7, Rev. 8, recommends the replacement of the UVTA after 1200 or more operations.
The counter facilitates the accurate accounting of RTB operations, while in no way compromising the effectiveness of the breakers intended function.
No violations or deviations were identified.
Item 4.5.1 RTS Reliabilit (S stem Functional Testin )
GL 83-28 Re uirement, On-line Functional testing of the RTS, including independent testing of the diverse t:rip features, shall be performed on all plants.
P~indin s
Xn a response to this item, the licensee stated in a letter dated January 24, 1985, that "...on-line, independent, functional testing of the undervoltage and shunt trip features is performed in Modes 1 through 4, after maintenance, in accordance with Surveillance Test Procedure (STP) I-33C, Time Response Testing of Reactor Trip Breakers".
Preventive Maintenance (PM) is performed on a 6 month interval which can be increased to a maximum of a one year inte'rva1 based on RTB performance
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Testing is also performed every 18 months in Modes 5 and 6 per STP I-33B; "Reactor'Trip,and ESF Logic Response Time".
The inspectors reviewed the STPs and records for completed tests and concluded that the licensee is meeting this requirement of the Generic Letter.
f No violations or deviations were identified.
8.
TI 2515/64 Rev.
1 (Closed)
"Near-Term Ins ection Follow-u to Generic I,etter 83-28" This TI was written to provide follow-up inspection on the licensee's response in the areas of equipment classification, vendor interface, post-maintenance testing, and RTS functional testing (covered elsewhere in this report).
a E ui ment Classification The criteria for identifying systems and components as safety-related are outlined in Section 3.2.2 of the Diablo Canyon Units 1 and 2 Final Safety Analysis Report (FSAR) Update.
The licensee utilizes the following three classifications:
Desi n Class I Any structure, system, or component necessary to assure; in the event of the safe shutdown earthquake (SSE):
(1) the integrity of the reactor coolant pressure boundary; (2) the capability to shutdown the reactor and maintain it in a safe shutdown condition; or (3) the capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to listed exposure guidelines.
Desi n Class II Plant features important to the operation of the plant but not required to perform one of the three functions listed above.
Desi n Class III Other plant features not related to plant safety or plant operation.
A licensee document entitled "Classification of Structures, Systems, and Components for Diablo Canyon Units 1 and 2 (Q-List)" identifies the design classification of plant equipment.
The inspectors reviewed this document against a sample of associated drawings, procedures, and surveillance tests for the following components and found them to be correctly classified:
(1) reactor trip and bypass breakers; (2) auxiliary feedwater pumps; (3) containment spray pumps; (4) motor operated valve No. FCV-440; and (5) motor operated valve No. V-3I I I
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The inspectors held discussions with licensee personnel and reviewed a sample of procedures and records to confirm the following:
t Written directives for structures, systems, and components which have been designated as safety-related were issued, reviewed, and controlled by plant and/or corporate management.
Personnel performing activities impacting safety-related equipment have received indoctrination and training per Quality Assurance (QA) procedure No. QADP-2.2 "Training and Indoctrination Program".
Periodic audits were scheduled and performed by QA personnel in accordance with QA procedure Nos.
QADP-18.1 "Audit Scheduling",
and QADP-18.2 "Quality Assurance Audits".
The inspectors also reviewed Audit No.
85035P entitled "Maintenance Program".
t Repair, maintenance, or modifications to equipment to correct
~ failures, malfunctions, deficiencies, deviations, defective, material and equipment, and nonconformances were performed, documented, and trended to determine the reliability of replacement components in accordance with the guidelines of Nuclear,'lant Operations procedure No.
NPAP C-40 "General Requirements For Plant Maintenance Programs".
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'",: No viol,'a'ti'ons'or deviations were identified.
b. 'endor Interface
t The.vendor-inter'face pxogram was reviewed to assure vendor information for,",sa'Set'y-relat'ed equipment was complete, current and
" controls,ed~thioughout,the life of the plant.
Technical Specifications',
test p'rocedures, and maintenance procedures were
,'eviewed to veri'fy tha't appropriate vendor, supplied information was
"incorporated -int'o applicable procedures.
~C PGSE Procedure '/PAP E-14/GOAP 9-123, Rev.
0 establishes the program
'by which supplier documentation is controlled.
The Engineering Department, is responsible for the control and distribution of supplier documentation.
The Project Engineer assigns the appropriate,'engineering discipline supervisor the task of determining the vendor information applicability.
When applicable, the supervisor is responsible for the technical review. If the review generates information important to the Nuclear Power Generation (NPG) group, a transmittal of the results will be sent to NRG.
NRG reviews the supplier documents for maintenance and post-maintenance testing recommendations.
NRGs recommendations, combined with engineerings recommendations, are compared with current procedures.
Recommendations not previously incorporated in the procedure will be resolved by either explaining why the recommendation is not applicable or updating the appropriate plant procedur I
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In. accordance with GL 83-28, the licensee has established a
preventive maintenance and surveillance program to cover the reactor trip breakers.
PG&E Procedure MP-E-51.7, Rev.
8 details the maintenance program for the Westinghouse DB-50 RTBs.
The procedure incorporates all of the recommendations supplied by Westinghouse in Technical Bulletin NSD-TB-83-02, Rev.
1, Addendum l.
A trending program for the breakers, governed by PGGE Procedure MP E-51.7B, was established to evaluate the effectiveness of the preventive maintenance program, forecast, degradation and adjust the maintenance frequency if applicable.
The program is presently fully implemented, however, the relative effectivenss will be more readily evident after more trending points become available.
A review of the spare parts associated with the RTB's was conducted to ascertain whether the inventory was adequate to support the above preventive maintenance program.
Based on the manufacturers recommendations and operating plant experience, it appears that. an adequate amount of replacement parts are available.
No violations or deviations were identified.
Post-Maintenance Testin The general requirements and responsibilities for the plant maintenance program are described in Administrative Procedure NPAP C-40 and detailed in others, including NPAP C-6 and its supplements.
These procedures ensure that testing is conducted before returning RTS Components and other safety-related components to operable status following maintenance or modification.
Additionally, paragraph
"D" of NPAP C-40 states that "Whenever a safety-related system, or subpart thereof, is to be intentionally removed from service for maintenance or other activities, the Shift Foreman shall be notified and the operability of the redundant engineered safety features shall be verified by test or inspection before the work can be authorized to proceed."
The inspectors reviewed plant procedures and confirmed that the program for post-maintenance and post-modification 'testing included the following elements:,
Documents. which relate to the maintenance or modifications also describe or reference the necessary testing prior to returning the structure,'. sy'tem, or component'o an operable status.
These documents require a signature indicating satisfactory completion of post-maintenance/modification testing before the document can be fi.led as a safety-related reCord; U
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Criteria exist and responsibilities are delineated for review and approval,of'modifications, maintenance, and subsequent.
testing.
K Criteria exist'and responsibilities are delineated for inspection and data verification of the testing by QA, QC, maintenance, engineering or other. responsible personne I C
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Administrative controls exist for preparation, documentation, review, approval of results, transfer, and retention of safety-related records in the records storage facility.
The controls provide for approval of the modification or maintenance packages; identification of personnel who performed the maintenance or modification; and, identification of the personnel who are required to inspect the work and subsequent testing.
No violations~or deviations were identified.
(Closed)
"QA Guidance For ATWS E ui ment That Is Not Safet -Related On June 1,
1984, the'RG approved publication of a final rule,
CFR 50.62, regarding> the reduction of risk from anticipated transients without scram (ATWS) events "for'ight-water cooled nuclear, plants.
This generic.letter was>issued to provide explicit QA guidance for non-safety related eq'uipment encompassed by %he ATWS rule.
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Section'i50.'6$ (d) of the. ATWS',rule~, required that each licensee develop and submit a'roposed schedule~for m'ecting the requirements of the rule within 180 days after issuance, of the QA guidance (issued April 16, 1985),
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The licensee
'responded to 'it&is it'em by letter on October 14, 1985 (gDCL-,85-'323,"J..iD.:Shigfer;.to H. R. Denton).
The licensee stated that,
"PGandE'is a'member of'the Westinghouse Owners Group (WOG) and is participa'ting ~n the WOG 'Generic. Design Program on Anticipated Transients WithoutlScram Mitigation System Actuation Circuitry (AMSAC)".
The WOG AMSAC 'design is presently undergoing review by the NRC.
PGandE plans to implement the requirements of 10 CFR 50'.62 for Westinghouse pla'nts by completion of the second refueling outages for Diablo Canyon Power Plant (DCPP)- Units 1 and 2 after final, issuance of the NRC Staff SER on the WOG AMSAC design.
No violations or deviations were identifie'd.
On October 25, 1985, an exit meeting was held with the licensee representatives identified in paragraph 1.
The. scope and findings of the inspection, as noted in this report, were discusse J J
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