IR 05000334/1988007
| ML20148C174 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 03/10/1988 |
| From: | Blumberg N, Dev M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20148C152 | List: |
| References | |
| 50-334-88-07, 50-334-88-7, 50-412-88-04, 50-412-88-4, NUDOCS 8803220299 | |
| Download: ML20148C174 (7) | |
Text
- _-___- __ ___ __ - __ _
.,'
.
.
"
.U.S. NUCLEAR REGULATORY COMMISSION
REGION I
50-334/88-07 Report Nos.- 50-412/88-04 50-334 Do'cket Nos.
50-412 OPR-66 License Nos. NPF-13 Licensee:
Duquesne Light Company r
P.O. Box 4 Shippingport, Pennsylvania 15077
,
Facility Name: Beaver Valley Power Station, Units 1 and 2 Inspection At:
Shippingport, P6?4ylvania Inspection' Con cted:
Febr@ry
, 1988
O 3 E Bg W
Inspector:
"
M. Dev, PE, Reactor Engineer
' date i
!O Approved by: <
V N. 8' lumb 4rg, Chief, Operational Program d6te Section, 38, DRS Inspection Summary:
Routine Unannounced Inspection conducted on February 8-12, 1988 (Inspection Report Nos. 50-334/88-07 and 50-412/88-04)
Areas Inspected:
Licensee's compliance to the NRC Order to modify Beaver
.
Valley Power Station (BVPS) Unit I license concerning Primary Coolant System Isolation (Event V) Valves, Incorporation of vendor recommended modifications to BVPS Units 1 & 2 Reactor Trip Breakers, and QA/QC interfaces.
l-Safety' Issue Management System (SIMS) Items: MPA-B-45, BVPS-1 (completed); and
'
MPA-B-80, BVPS-1 and BVPS-2 (completed).
I Results:
The licensee action to modify the BVPs Unit I license concerning Primary Coolant System Isolation (Event V) valves were found complete and satisfactory. Also, vendor recommended modification to BVPS Units 1 and 2
!
l reactor trip breakers per GL 83-28, Item 4.1 were found adequately implemented and complete.
No violations or deviations were identified.
l l
$O Nbb
$4 l
i G
!
l w
l..
,
.
,
.
.
INSPECTION DETAILS 11. 0 Persons Contacted Duquesne Light Company (DLC):
Beaver Valley Power Station (8VPS) Units 1 & 2
. J. Crockett, Senior Manager, Nuclear Operations
- D. Hunkele, Director, Quality Assurance, Operations
- F. Lipchick, Senior Licensing Supervisor M. Pergar, Quality Control Supervisor
- B. Sepelak, Licensing Engineer
- J. Vassello, Director, Licensing
- J. Waslousky, Quality Assurance Supervisor J. West, Test-Engineer United States Nuclear Regulatory Commission J. Beall, Senior Resident Inspector, Beaver Valley Power Station
.
Unit 1 & 2
- S. Pindale, Resident Inspector, Beaver Valley Power Station Units 1 & 2
- R. Winters, Reactor Engineer, Region 1.
- Denotes those attending the exit meeting.
The inspector also contacted other administrative and technical personnel during the inspection.
2.0 BVPS Unit 1 Primary Coolant System Pressure Isolation (Event V) Valves -
License Modification, MPA-B-45 2.1 Background The Reactor Safety Study (RSS), WASH-1400, identified in a PWR an intersystem loss of coolant accident _(LOCA) that is a significant contributor to risk of core melt accidents (Event V).
The design examined in the RSS contained in-series check valves isolating the high pressure primary coolant system (PCS) from the low pressure injection system (LPIS) piping. The scenario which leads to the Event V accident is initiated by the failure of these check valves to function as a pressure isolation barrier against reactor coolant system (RCS) pressure.
This causes an overpressurization and rupture of the LPIS low pressure piping which results in a LOCA that bypasses containmen.
.
To better define the Event V concern, all light water reactor licensees were requested by letter dated February 23, 1980, to provide the following in accordance with 10 CFR 50.54(f):
a.
Describe the valve configurations and indicate if an Event V isolation valve configuration existed within the Class 1 boundary of the high pressure system piping, e.g., (1) two check valves in series, or (2) two check valves in series with an open motor-operated valve, b.
If either of the above Event V configurations existed, indicate whether continuous surveillance or periodic tests were being performed on such valves to ensure integrity. Also indicate whether valves had been known, or found, to lack integrity.
c.
If either of the above Event V configurations existed, indicate whether plant procedures should be revised or if plant modifications should be made to increase reliability.
In addition to the above, licensees were asked to perform individual check valve leak testing before plant startup after the next scheduled outage.
2.2 Order Implementation Review and Findings In a letter to the NRC dated March 17, 1980, the licensee concluded that the BVPS Unit 1 Low Pressure Safety Injection System (LPSIS)
contained Event V isolation valve configurations.
It is connected to the cold-leg side of each of the three Primary Coolant System loops.
Each cold-leg segment of the LPSIS has two check valves leading away from the reactor vessel with all three segments joining together and then leading outside containment to a single, normally open, motor-operated valve. Three of the check valves (151-10, -11 and-12) and the MOV (SI-890C) required periodic leak testing in accordance with the ASME B&PV Code,Section XI.
The other check valves (ISI-25, -24 and -23) were not required to be leak tested.
The Franklin Research Center performed a technical evaluation and l
concluded that the licensee needed to modify the plant Technical Specifications for BVPS Unit-1 to incorporate periodic testing of all
,
the LPSIS check valves.
This would be an effective measure in substantially reducing the probability of an intersystem loss of l
coolant accident (LOCA) occurring in these lines, and means of l
increasing the probability that these lines would be able to perform l
their safety functions.
l
l l
l
F.
,
.
.-
The licensee conducted two leak rate tests of the LPSIS cold-leg check valves SI-10, -11, -12, -23, -24 and -25 to determine the possible leakage of the primary coolant system in-line check valves and their postulated failure (Event V).
These tests were satisfactorily conducted during November 1980.
Inspector's review of the test results did not identify any problems.
On April 26, 1981, the NRC issued an order requiring the licensee to perform leak rate testing of Event V pressure isolation valves and implement Technical Specifications changes to incorporate their periodic surveillances. Accordingly, the licensee amended the plant Technical Specifications and established an operating surveillance test, OST-1.11.16 to conduct leakage testing of the Reactor Coolant System Pressure Isolation Valves.
The inspector reivewed the design change packages (DCPs)-360 for the installation of the pressure gauges to monitor check valves; and DCP-434 for the installation of LPSIS check valves test rigs.
Their associated safety evaluations were found to have been adequately reviewed for any safety concerns, and the maintenance work orders were properly dispcsitioned. The inspector also reviewed the operation surveillance leakage testing of RCS pressure isolation valves, conducted on April 28, 1987, in accordance with the test procedure OST-1.11.16. The procedure has established acceptance criteria, initial conditions and test instruction.
The test met the plant Technical Specifications requirements delineated in paragraphs 4.4.6.3.1 and 4.0.5 related to surveillance and in-service testing. The
-
corrective and preventive maintenance history of these Event V pressure isolation valves, during the period January 1,1976 through February 9, 1988 was also reviewed. No significant problem was identified. The licensee action was found adequate and timely.
On November 12, 1987, the licensee submitted a proposed amendment to the plant Technical Specifications. This amendment added 15 valves, in addition to previously identified six Event V LPSIS valves, which also perform pressure isolation function. Also included in this proposed change are the revised Limiting Condition for Operation (LCO), Action and Surveillance Requirements.
The license amendment is currently in the NRC review cycle.
2.3 Conclusions The licensee has completed the action required by the NRC Order to modify BVPS Unit I license concerning Primary Coolant System Pressure Isolation Valves.
Based on the review of related system design change documentation, Technical Specifications amendment, implementation of operations surveillance program, and discussion with the cognizant test and engineering personnel, the inspector determined that the licensee action was adequate.
This closes the multiplant action (MPA) item B-45.
-. _ - - _ _ _ _ _ - _ - _ - _ _ - _ _ - _ - _ _ _ _ - _ _
l
- ,
.
'3.0 BVPS Units 1 and 2 Reactor Trip Breakers Vendor Recommended Modification 1 MPA-B-80 3.1 Dackground On February 25, 1983, during startup of the Salem Unit 1 plant both Westinghouse 08-50 reactor trip systen (RTS) circuit breakers failed to open automatically upon receipt of a valid trip signal on a low-low steam generator water level.
This failure to trip was attributed to a binding with the undervoltage trip attachment (UVTA)
located inside the breaker cubicle.
The reactor was tripped manually from the control room about 30 seconds after the automatic trip signal was generated.
Subsequent to the February 25 event, it was determined that a failure of the breakers to cpen following receipt of an automatic reactor trip signal also had occurred on February 22, but had not been detected at that time by the licensee.
In addition, the NRC has become a vare of approximately 25 other instances wherein the UVTAs failed to trip the RTS breakers within the acceptance time specified by the licensees.
Sluggish operation of the UVTAs may indicate that the breakers are deteriorating to the point where complete failure to trip may ensue.
This situation has caused the NRC to require licensees to expand their maintenance and surveillance testing of RTS breakers.
The Commission reviewed several intermediate-term actions to be taken by licensees and applicants as a result of the Salem anticipated transient without scram (ATWS).
The actions were developed on the basis of information contained in NUREG-1000,
"Generic Implications of ATWS Events at the Salem Nuclear Power Plant." NRR issued GL 83-28 to all licensees and applicants on July 8, 1983, requiring the utilities,' pursuant to 10 CFR 50.54(f),
to furnish the status of current conformance with the positions contained in GL 83-28 and plans and schedules for any needed improvements.
This inspection is intended to verify the satisfactory completion of the licensee's action required in item 4.1 of GL 83-28 which concerned vendor recommended modifications for reactor trip
'eakers at the BVPS Units 1 and 2.
3.2 Implementation Review and Findings
.
3.2.1 Beaver Valley Power Station Unit 1 Reactor Trip Breakers BVPS Unit 1 utilizes Westinghouse 0B-50 breakers in the rod control reactor protection scheme.
Testing by Westinghouse on 0B-50 breakers after Salem ATWS event indicated that an additional margin on the trip
_ _ _ _ _ _
- _ _ _ _
_ _ _ _ _ _
s
'
,
interaction of the undervoltage trip attachment (UVTA) existed if the overcurrent trip brackets, which are mounted on the trip bar, were removed.
In accordance with the vendor letter DLW-83-581, dated May 9, 1983, the licensee inspected the reactor trip and reactor trip by pass breakers.and found overcurrent trip brackets without the overcurrent trip device. As a result, a station modification request was initiated and during the third refueling outage, the overcurrent trip brackets were removed.
The inspector reviewed the station modification request (SMR)-822, dated May 27, 1983, and the maintenance work requests,(MWR)-836399, dated May 17, 1983 and MWR-837384, dated September 9, 1983.
Inspection of the reactor trip breakers and its associated modifications were found to have been performed in accordance with the vendor instruction and approved station procedure. The vendor recommended modification was adequately reviewed by the licensee engineering group and on-site review committee.
No unreviewed safety concerns were identified.
3.2.2 Beaver Valley Power Station Unit 2 Reactor Trip Breakers BVPS Unit 2 utilizes Westinghouse DS-416 breaker in the rod control reactor protection scheme. Westinghouse evaluations identified potential for misoperation of 05-416 reactor trip switchgear undervoltage trip attachments.
Through letter DMW-3738 dated November 28, 1983, Wescinghouse advised the licensee of the corrective action.
Accordingly, Westinghouse provided a new undervoltage trip attachment with modified grooves to accomodate the new retaining ring. A revised design drawing and the field installation procedure were also provided for proper alignment and interface of the attachment with the breaker trip shaft. Westinghouse performed the undervoltage trip attachment field modification prior to the BVPS Unit-2 startup The inspector reviewed the Westinghouse field change notice (FCN) DMWM-10592 dated May 30, 1984, including associated installation procedure and field change request.
The Westinghouse QA and the site manager verified the acceptability of the completed work and the FCN was closed.
3.3 Conclusions i
l The licensee implemented the BVPS Unit 1 08-50 reactor trip breaker l
modification during the third refueling outage. Whereas, i
Westinghouse site construction and installation group completed the l
BVPS Unit 2 0S-416 reactor trip breaker modifications prior to l
t L
q
.
l
startup.
Thus, the licensee's action to implement the vendor recommended modification of the reactor trip breakers per GL 83-28, Item 4.1 was found complete.
This closes the multiplant action (MPA)
item B-80.
4.0 QA/QC Interfaces The inspector verified that the BVPS Unit 1 QA had reviewed the pressure isolation (Event V) valve related design changes and modifications, including the operations surveillance test procedure, maintenance work requests and the Technical Specifications changes.
Field installation, includir-g witness and holdpoint verification of the quality control activities were found to have been properly covered by the plant QC persc,nnel.
Similarly, the QA/QC involymerit for the BVPS Unit 1 reactor trip breaker modification was founc' scequate.
Since the Westinghouse field installation group conducted the BVPS Unit 2 reactor trip breaker modification prior to the plant startup, the Westinghouse QA was found to have been actively involved in the modification work activities performed in accordance with the field change notice and the installation procedure.
Based on the review of the design changes and modifications documentation and discussion with the cognizant individuals, the licensee's QA/QC interfaces in the areas inspected were found adequate.
5.0 Management Meetings The licensee management was informed of the scope and purpose of this inspection at an entrance meeting conducted on February 8,1988.
The findings of the inspection were discussed with the licensee representatives during the course of this inspection. An exit meeting was conducted on Februaty 12, 1988 at the conclusion of this inspection to provide the finding of this inspection to the licensee management (see paragraph 1.0 for attendees).
At no time during this inspection was written material provided to the licensee. Also, the licensee indicated that no proprietary information was involved within the scope of this inspection.