ML20023B808
| ML20023B808 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 04/28/1983 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8305060403 | |
| Download: ML20023B808 (10) | |
Text
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DUKE POWER GOMPANY P.O. HOK 33189 CHARLOTTE, N.O. 28242 HAL B. TUGKER TER.EPHONE (704) 373-4531 vece paramewr April 28, 1983
= = * = =
Mr. Harold R. Denton, Director i
Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention:
Ms. E. G. Adensam, Chief Licensing Branch No. 4 Re: McGuire Nuclear Station Docket Nos. 50-369, 50-370
Dear Mr. Denton:
Duke Power Company has described the actions taken regarding recent problems with the DS-416 breaker undervoltage (UV) devices in a letter dated April 18, 1983 and in a meeting with the NRC Staff on April 19, 1983. The NRC reviewed the information provided and, in a telephone conference call on April 26, 1983, outlined additional actions it felt necessary to satisfactorily resolve the issue. These additional actions were discussed in another conference call on April 27, 1983. The purpose of this letter is to provide the additional information requested by the Staff.
Westinghouse has been involved in the undervoltage device problems at McGuire since early in March. Duke and Westinghouse personnel have worked together in the identification and resolution of the UV devices. With one exception, the deficiencies noted in the DS-416 UV device have been discovered on the breakers at McGuire. Thus, the recommendations that have been issued by Westinghouse have been implemented at McGuire. These include:
- 1) Replacement of UV devices with new devices with all manufacturing problems corrected and with modified grooves to accommodate the new retaining rings.
- 2) Installation checks on UV attachment to verify proper alignment and interface with the breaker trip shaft.
- 3) Alerting operators to potential problems relative to reactor trip switchgear.
- 4) Re-emphasize to the operators indications available to detect failure of rods to insert into the core.
Westinghouse also recommended in a March 31, 1983 letter that the operators initiate a manual trip following any reactor trip from the reactor protection system. Duke did not implement this recommendation since 1) existing procedures (Reactor Trip and ATWS procedure) require a manual trip if reactor trip does not occur, and 2) a modification to the reactor trip breakers was made such$6k, i
8305060403 830428 PDR ADOCK 05000369 S
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Mr. Harold R. Denton, Director April 28, 1983 Page 2 that the shunt coil is energized as a result of any reactor trip signal from the reactor protection system. This automatic shunt trip of the reactor trip breaker obviates the need for a follow-up manual trip by the operator.
(Note:
Copies of the Reactor Trip Procedure and the ATWS Procedure were sent to the NRC by Federal Express delivery on April 27, 1983.)
Thus, with all the actions taken by Duke, the potential safety problems identified by Westinghouse in its Part 21 notification and its letter of March-31, 1983 to the NRC have been addressed.
The NRC Staff identified additional surveillance that should be performed to assure the operability of the reactor trip breakers. Duke evaluated the Staff's proposed testing and discussed this testing in a conference call on April 27, 1983. As a result, the following testing will be performed in addition to that required by Technical Specifications.
It is proposed that these additional tests be added to the Technical Specifications only after the program has had the benefit of additional review to determine the generic applicability.
Test Frequency 1.
Independent test of UV and Every startup if not performed shunt trip.
within previous 7 days.
2.
Test of Manual Trip from Every startup if not performed Control Room, within previous 7 days.
3.
Response time test of reactor Every 62 days on a staggered test trip breaker on UV signal from basis such that one breaker is RPS.
tested every 31 days.
4.
Functional test of shunt trip Every 62 days on a staggered test of reactor trip breakers.
basis such that one breaker is tested every 31 days.
5.
Force test on trip bar and UV Each refueling.
device of reactor trip breakers and bypass breakers.
6.
Response time test of bypass Each refueling.
breaker on UV signal from RPS.
7.
Functional test of shunt trip Each refueling.
on bypass breakers.
(A copy.of the procedures for Items 1 and 2 is attached.)
Mr. Harold R. Denton, Director April 28, 1983 Page 3 The startup testing and bimonthly testing specified will be performed at this frequency for at least one year. This will include trending of breaker response times. After one year an evaluation of the benefits versus the impact of the testing will be made. A decision on the need to change the frequency would then be made and appropriate changes proposed. Accordingly the following is a recommended license condition for inclusion in the McGuire, Units 1 and 2 Facility Operating Licenses:
"The licensee shall implement the reactor trip breaker and bypass breaker testing as described in Mr. Hal B. Tucker's letter of April 28, 1983. The licensee shall not maka any major modifications to this program unless prior NRC approval is received.
Major modifications are defined as:
a.
Elimination of any identified testing, b.
Changes in the frequency of performing the identified testing, and c.
Reduction in the scope of any of the required testing."
During the meeting with the NRC Staff on April 19, 1983 a copy of several test procedures and a maintenance procedure were provided. The Staff, in reviewing the maintenance procedures, did not see evidence of adequate QA involvement.
In a conference call on April 27, 1983 it was explained that the maintenance procedure by itself was not the only document that controlled QA/QC activities.
The scope of QA coverage is specified in Maintenance Management Procedures which described the work request system and QA requirements detailing specific inspection requirements for electrical equipment including circuit breakers. Copies of the following documents were sent to the NRC Staff on April 27, 1983 by express package service.
- 1) Copy of McGuire Nuclear Station Work Request Form
- 2) Procedures describing work request
- Maintenance Management Procedure 1.0
- Maintenance Management Procedure 3.0
- 3) QA/QC requirements for inspection of electrical equipment
- 4) Revised copy of Air Circuit Breaker Maintenance Procedure Duke is pursuing with Westinghouse a follow-on evaluation and reliability program for the DS-416 UV attachment. The scope and objectives of this program are being developed and will be provided to the NRC Staff in the near future.
Duke Power Company believes that the actions taken to date at McGuire in response to the DS-416 UV device problems and the commitments made for future actions provide a sufficient basis for operation of both McGuire units. All of these
Mr. Harold R. Denton, Director April 28,-1983 Page 4 actions have been discussed in some detail with the NRC Staff and general agreement reached on the essential points. Accordingly, it is our intention to proceed with startup of both units consistent with the plant schedule (currently Unit 1 criticality is scheduled for May 4,1983 and Unit 2 for May 2, 1983). However, operation will be limited to zero power physics testing i
on both units until receipt of_the NRC Staff Safety Evaluation Report on the j
reactor trip breakers.
Please advise if there are any questions regarding this matter.
'Very truly yours, a%/
Hal B. Tucker CAC/php Attachment cc:
Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303 Mr. W. T. Orders NRC Senior Resident Inspector McGuire Nuclear Station
IP/0/A/3010/09 10.2 Manual Input Junction Test and Independent Verification.
NOTE: This procedure provides a means of checking the reactor trip breaker using the " Manual Input Functional Test" pushbutton, and also provides a means for independent verification of both undervoltage (uy) and shunt trip.
/
10.2.1 Verify that bypass breaker for the train under test is open.
/
10.2.2 On the Logic Test Panel, place the " Input Error Inhibit"
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switch to the " Inhibit" position.
Close reactor trip breaker, as necessary.
/
10.2.3 Verify the blocking diode on A518 by measuring the resistance from TB506-5 to E101-1.
(Back of SSPS cabinets).
/
10.2.4 Verify that RT52b and RT33b contacts are open by measuring for OVDC between terminal 5-4(+) ar* GND.
(In back of reactor trip breaker switch gear cabinet).
/
10.2.5 Verify that the switch gear BY33b contact is closed by measuring for a short circuit between terminal 5-4(+) and terminal 5-2(-).
/
10.2.6 Have the byp' ass breaker for the train under test racked in to the connect position and closed.
CAUTION: This bypass breaker must remain energized for the duration of the manual testing of this section, otherwise, a reactor trip will occur.
/
10.2.7 Verify that BY52b and BY33b contacts are open by measuring for open circuit between terminal 5-4 and 5-2.
/
10.2.8 Have the bypass breaker controlled by the train under test racked to the " Test" position and closed.
/
10.2.9 Place the " Logic A" test switch in position 7 (Pressurizer High Pressure Trip)
/
10.2.10 At the switchgear cabinet for the train under test, depress and hold in the "UV Test" button.
(This will enable reactor trip independent of shunt trip).
/
10.2.11 In the " Manual Input Function Test" portion of the logic test panel, depress any two pushbuttons. At the control board, observe that the reactor trip breaker for this train de-energizes / opens, the bypass breaker in the " Test" position opens, and the "UV Coil Voltage" meter reads approximately zero volts while the switches are depressed.
2
/
10.2.12 Return " Logic A" switch back to off position.
/
10.2.13 Release "UV Test" button.
/
10.2.14 Reclose reactor trip breaker under test.
/
10.2.15 At the switchgear cabinet for the train under test, depress and release the "ST Test" pushbutton.
(This is to verify reactor trip by means of shunt trip independent of undervoltage trip).
/
10.2.16 At the control board, observe that the reactor trip breaker for this train de-energizes / opens.
/
10.2.17 Verify that RTS2b contact is closed by measuring for 48VDC between terminal 5-4(+) and GND.
/
10.2.18 Close the reactor trip breaker of the train just tested and rack out the bypass breaker controlled by the train under test.
/
10.2.19 Verify that RT52b contact is opened by measuring for OVDC between terminal 5-4(+) and GND.
/
10.2.20 Have the bypass breaker of the train under test opened.
/
10.2.21 Verify that.BY52b contact is closed by measuring for short circuit between tecninal 5-4 and terminal 5-2.
/
10.2.22 Have the bypass breaker of the train under test racked out to the disconnect position.
/
10.2.23 Verify that BY33b contact is closed by measuring for a short circuit between terminal 5-4 and terminal 5-2.
a v
IP/0/A/3010/05 10.6 Manual Input Function Test NOTE: This procedure provides a means of checking the reactor trip breaker using the " Manual Input Function Test" pushbutton.
It also provides a means for independent verification of reactor trips (shunt and undervoltage) and also records reactor trip breaker response time.
CAUTION:
Insure the bypass brecker for the train is still racked in to the connect position and closed. This bypass breaker must remain energized for the duration of the manual testing of this section or a reactor trip will occur.
/
10.6.1 Verify that BY52b and BY33b contacts are open by measuring for Open Circuit between terminal 5-4 and terminal 5-2.
(Back of RX Trip Breaker Cabinet).
CAUTION:
INSURE OPERATOR IS AWARE THAT TO RACK THE BYPASS BREAKER FOR THE OTHER TRAIN IN TOO FAR (P'.ST THE " TEST" POSITION TO THE " CONNECT" POSITION AND CLOSING IT WILL RESULT IN A REACTOR TRIP.
/
10.6.2 Have the bypass breaker controlled by the train under test racked to the " TEST" position and closed.i
/
10.6.3 On one channe.1 of the visicorder, connect input to TB7-1 and TB7-2 of the reactor trip breaker being timed. (BREAKER CONTACT).
/
10.6.4 On another channel of the visicorder, connect input to TB1-1 and TB1-2 of the reactor trip breaker being timed.
(UV COIL)
/
10.6.5 Close reactor trip breaker that is being tested if necessary.
/
10.6.6 Place the " Logic A" test switch in position "7" (Pressurizer High Pressure Trip).
/
10.6.7 At Reactor Trip Switchgear Cabinet, depress "UV Test" button for the train being tested.
(This enables UV reactor trip independent of shunt trip).
/
10.6.8 Start recorder at a speed of 10 inches per second.
/
10.6.9 In the " Manual Input Function Test" portion of the Logic Test Panel, depress any two pushbuttons. At the Control Board, observe that the reactor trip breakers for this train de-energize /open, the bypass breaker in the " Test" position opens, and the "UV Coil Voltage" meter reads approximately zero volts while the switches are depressed.
/
10.6.10 Stop recorder.
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/
10.6.11 Release "U/ Test" buttons.
/
10.6.12 By the use of the reactor chart determine the reactor trip breaker response time.
/
10.6.13 Record response time value on Enclosure 11.6.
If less than allowable value continue, if not notify proper IAE personnel.
/
10.6.14 Place " Logic A" test switch back to the "0FF" position.
/
10.6.15 Reclose reactor trip breaker under test.
/
10.6.16 At the swit chgear cabinet for the train under test, depress and release the "ST TEST" pushbutton.
(This is to verify reactor trip by means of shunt trip independent of undervoltage trip).
/
10.6.17 At the control board, observe that the reactor trip breaker for this train de-energizes / opens.
/
10.6.18 Verify the RT52b contact is closed by measuring for 48 VDC between terminal 5-4(+) and GND.
/
10.6.19 Close the reactor trip breaker of the trdin just tested and rack out the bypass breaker controlled by the train under test.
/
10.6.20 Verify that RT52b contact is opened by measuring for 0 VDC between terminal 5-4(+) and GND.
/
10.6.21 Log test equipment used for time response as needed on
- 1.7.
/
10.6.22 If no further testing is to be performed on this traing, proceed to Step 10.9.
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O IP/0/A/3010/05 ENCLOSURE 11.6 Page 1 of 1 DATA SHEET REACTOR TRIP BREAKER RESPONSE TIME REQUIRED
< 15 SEC REACTOR TRIP BREAKER RESPONSE TIME RECORDED DOES REACTOR TRIP BREAKER PASS ACCEPTANCE CRITERIA YES NO IS RECORDER CHART ATTACHED TO THIS DATA SHEET?
YES NO UNIT BEING TESTED
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TRAIN BEING TESTED WORK REQUEST NUMBER l
DATE RECORDED BY Y
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IP/0/A/3010/05 ENCLOSURE 11.7 PAGE 1 of 1 TEST EQUIPMENT DVM NO.
CAL. DUE DATE I
MODEL NO.
RECORDER NO.
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DATE TIME BASE CHECKED VOLTAGE SOURCE NO.
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