ML20064C934
| ML20064C934 | |
| Person / Time | |
|---|---|
| Site: | McGuire  |
| Issue date: | 02/24/1994 |
| From: | Mcmeekin T DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9403100338 | |
| Download: ML20064C934 (23) | |
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, Duke 1%erCompany T C M6kms
, McGuite Nuclear Generation Department tite President 12709Hagers FerryRoad(MG01\P) (7(H)8754800 Huntersville, NC2807885 (704)STS4M9 Fax DUKEPOWER February 24, 1994 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555
Subject:
McGuire Nuclear Station, Units 1 and 2 :
Docket Nos. 50-369 and 50-370 Inservice Testing Plan (IST)
Second Interval Plans for Unit 1 i Response to NRC Safety Evaluation (SE)
Relief Request 92-04
Dear Sir:
By letter dated October 12, 1992, the McGuire Nuclear' Station, Unit 1, second ten-year IST program plan was submitted for NRC review. A Safety Evaluation-(SE) providing the results of the NRC staff review of the relief requests submitted within the Unit 1 IST program plan was provided by an October 12, 1993 NRC letter.
As documented within the SE, some_of the requests for relief that were submitted were denied. The October 12, 1993 NRC l
letter stated that for relief requests that have been denied, the licensee should, within 90 days from the date of the SE transmittal letter, comply with applicable Section XI l requirements and Generic Letter 89-04 guidelines. That any l additional information supporting the denied relief requests l should also be submitted within the same time period.
Accordingly, please find attached the actions that have been taken regarding the denied requests, including additional j information supporting the denied relief requests.
By letter dated January 6, 1994, a revised IST program plan for Unit 1 was provided. The revision updated the Unit 1 i IST program plan to comply with the 1989 edition of ASME l Section XI, as suggested within the October 12, 1993 NRC j letter. The information provided by this letter is i consistent with the information that was submitted by the January 6, 1994 letter.
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I U. S. Nuclear Regulatory Commission February 24, 1994 page 2 i
When the initial IST program plan for Unit 1 was submitted, modifications were in progress that impacted certain requests for relief. In particular, relief requests associated with the diesel generator room sump pumps and the containment spray header check valves. As discussed within a the NRC staff SE (see Sections 2.2 and 2.3 of the SE), these modifications had been completed for Unit 1 and were still in progress for Unit 2. Please be advised that these modifications have been completed for Unit 2 as well.
Please contact Paul Guill at (704) 875-4002 if there are any questions regarding this response.
Very truly yours,
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T. C. McMeekin xc: Mr. S. D. Ebneter Regional Administrator, Region II U. S. Nuclear Regulatory Commission
'101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. George F. Maxwell Senior NRC Resident Inspector, McGuire McGuire Nuclear Station Mr. Victor Nerses, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission One White Flint North, Mail Stop 9H3 Washington, D.C. 20555
4 ATTACHMENT DUKE POWER COMPANY MCGUIRE NUCLEAR STATION, UNIT 1 Response to NRC Safety Evaluation of Relief Request 92-04 that was Transmitted October 12, 1993 A summary of the actions taken in response to the relief requests that were denied are presented in the table below:
Summary of Actions Taken Regarding Denied Relief' Requests RELIEF REQUEST TER DUKE ACTIONS NUMBER SECTION Generic Pump 2.1.3 The request has been deleted and Number I.3.3 re-submitted, specifically for the RN Pumps only. The request has been updated to OM-6.
Pump 2.3.1 The request'has been modified and Number I.4.2 re-submitted to provide additional information. The request has been updated to OM-6.
Pump 2.5.1 The request has been modified and Number I.4.4 re-submitted to provide additional information. Will continue to perform full-head curve test and reference a single point.
Pump 2.6.1 The request has been modified and Number I.4.5 re-submitted to provide additional information. The request has been updated to OM-6.
Pump 2.7.1 The request has been modified and Number I.4.6 re-submitted to provide additional information.
Pump 2.8.1 The request has been deleted. The Number I.4.7 pumps will be tested in accordance with OM-6, using the single point parameter comparison.
Generic Valve 3.1.1 The request has been deleted.
Number (III) Valves will be tested in accordance with OM-10.
Valve 3.12.1 Additional information providing the Number RR-VG1 reason why the modification was delayed is provided.
By an October 12, 1993 letter the NRC transmitted a Safety l Evaluation (SE) which provided the results of their review of the McGuire Nuclear Station, Unit 1, second ten-year interval IST program plan. The NRC SE stated that for relief requests that were denied, the licensee should either comply with applicable Section XI requirements or additional information supporting the denied relief requests be submitted within 90 days from the date of the SE transmittal letter.
Briefly, there were six (6) relief requests for pumps and two (2) relief requests for valves that were denied. The NRC Se provided the staff's concerns and the basis for denying the requests for relief. The following provides Duke's position regarding the NRC staff's concerns and the action taken in response to the NRC staff's denial of each of the eight (8) requests for relief.
NRC CONCERN REGARDING RELIEF REQUEST I.3.3 JTER SECTION 2.1.311 The licensee has not provided suf ficient in: formation with which to evaluate the request for relief from the requirements of IWP-4520(b) because the specific pumps and their operating frequency have not been identified. Therefore, it is not possible to determine how much the proposed calibration form the l
10 Hz deviates for the 1/2 minimum pump shaft rotational. speed. .
In addition, the licensee has not provided in this request information concerning the repeatability and accuracy of the instruments from 10 Hz to 1/2 minimum pump shaft rotational speed. Therefore, relief is denied. The licensee should provide this information and resubmit this relief request.
DUKE'S POSITION REGARDING RELIEF REQUEST I.3.3:
Item five (Calibration of vibrational instruments between 10-1000 Hz) of relief request I.3.3 was denied based on insufficient i
information because the specific pumps and their operating frequency had not been identified. This general relief request has been deleted and a new request for relief has been re-submitted. The new and updated specific relief request was provided for NRC review by a January 6, 1994 Duke Power letter.
The specific request for relief is provided in Section I.4 of the McGuire Pump and Valve IST Program Manual for Unit 1 (Manual provided by the January 6, 1994 Duke Power letter) as Relief Request I.4.7. The specific relief request applies to the Nuclear Service Pumps only. For convenience, Relief Request I.4.7 is enclosed with this response. In addition, the request for relief has been updated to comply with the requirements specified by OM-6 and to include the additional specific information requested.
i McGuire Unit 1 Specific Relief Reauest RELIEF REQUEST: 1.4.7 PUMPS: 1RNPU0003,1 A Nuclear Service Water Purnp ;
1RNPU0004,18 Nuclear Service Water Pump j TEST REQUIREMENT: OMa-1988 Part 6, Section 4.6.1.6 requires the frequency response range of the vibration measuring transducers to be from one-third minimum pump shaft rotational speed to at least 1000 Hz.
BASIS FOR RELIEF: The Nuclear Service Water pumps are designed to operate at 1185 rpm.
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- This speed yields a frequency of 19.75 Hz (1185/60). The vibration 1 instrumentation used cannot be calibrated to the required one-third minimum shaft speed of 6.58 Hz (19.75/3).
ALTERNATE TESTING: In lieu of OMa 1988 Part 6, Section 4.6.1,6, the vibration instrumentation will be calibrated over a range of 10 to 1000 Hz. This calibration range encompasses most of the noise contributors, and repeatability within this range is very good. Accuracy of measurement within this range is addressed in relief request 1.3.1 l
l 11/1/93 SECTION 1.4 11 OF 11
McGuire Unit 1 General Relief Reauest RELIEF REQUEST: 1.3.1 PUMPS: All pumps in the Inservice Test Program TEST REQUIREMENTS: 1) OMa-1988 Part 6 Section 6.1 (Table 3a) specifies the allowable range
, for acceptable operation of vibration measurements.
- 2) OMa-1988 Part 6 Section 4.6.1.1 (Table 1) requires the accuracy of vibration amplitude measurements to be +/ 5 % of full scale.
BASIS FOR RELIEF: 1) Experience has shown that smooth operating pumps (Vr s 0.075 in/sec) often fall in the alert range of vibration measurement when compared to the acceptance enteria given in OMa-1988 Part 6, Table 3a. The Table included with this relief request allows for acceptable ranges of vibration measurement for this classification of pumps. This ,
proposal provides an acceptable level of quality and safety given the .
minimum limits.
- 2) Vibration measurement instrumentation currently in use is digital instrumentation. Using our present instrumentation and accounting for all instrumentation uncertainties in the calibration process, the requirement of +/- 5% instrument accuracy cannot be achieved.
ALTERNATE TESTING: In lieu of the vibration specifed in OMa-1988 Part 6, Table 3a, the following ranges shall be used. These ranges are based on current vibration standards (vibration seventy charts).
Acceptable Alert Required Range Range Action Range For all pumps when 0 to 0.19 in/sec > 0.19 s 0.45 in/sec > 0.45 in/sec Vr s 0.075 in/sec For centrifugal pumps, s 2.5
- Vr > 2.5
- Vr to 6
- Vr or > 6
- Vr or when Vr > 0.075 in/sec > 0.325 to 0.70 in/sec > 0.70 in/sec :
For reciprocating pumps, s 2.5
- Vr > 2.5
- Vr to 6
- Vr > 6
- Vr i when Vr > 0.075 in/sec For intemal gear positive s 2.5
- Vr > 2.5
- Vr to 6
- Vr > 6
- Vr displacement pumps, when Vr > 0.075 in/sec 11/1/93 SECTION l.3 1OF2
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i McGuire Unit 1
- General Relief Reauest l
RELIEF REQUEST: 1.3.1 (Continued) ,
in lieu of the vibration instrument accuracy requirements of OMa 1988 Part 6 Table 1, the loop accuracy of vibration measurements will be +/-
6.56 % of reading. This accuracy is based on the Root Sum of Squares method and includes the accuracy of the vibration probe (+/- 5.0%) and the accuracy of the calibration instrument (+/- 4.25%). This accuracy is the best that can be reasonably obtained from the state of the art '
instrumentation used.
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11/1/93 SECTION 1.3 20F2 !
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9 NRC CONCERN REGARDING RELIEF REQUEST I.4.2 TER SECTION 2.3.1):
The licensee intends to monitor the EDG fuel oil transfer pumps I discharge pressure for information purpose only and it will not be compared to any acceptance criteria. The licensee's rational is that system limitations restrict the discharge pressure to less than or equal to 55 psig, but that the pumps could easily pump against 150 psig. Since the transfer pumps are positive displacement type pumps, for a given speed, the pump flow rate is essentially constant and independent of pump discharge pressure.
Fluctuations in the discharge pressure could be indicative of degradation or an impending safety concern. The licensee has not
! demonstrated the hardships or impracticality in meeting the Code requirements. Therefore, pending such demonstration by the licensee, it is recommended that this relief request relating to the discharge pressure be denied.
DUKE'S POSITION REGARDING RELIEF REOUEST I.4.2:
The relief request for not measuring the discharge pressure of j the EDG fuel oil transfer pumps was denied because the NRC reviewer states that fluctuations in the discharge pressure could be indicative of degradation or an impending safety concern.
Further, the NRC reviewer also stated that the hardship or impracticality associated with meeting the Code requirements was not demonstrated. This relief request has been modified to provide some additional technical basis for not measuring the discharge pressure. The modified relief request was submitted to the NRC for review by a January 6, 1994 Duke Power letter. The specific request for relief is provided in Section I.4 of the
! McGuire Pump and Valve IST Program Manual for Unit 1 as Relief Request I.4.2. For convenience, Relief Request I.4.2 is enclosed with this response. In addition, the request for relief has been updated to comply with the requiremer.ts specified by OM-6 and to include the additional specific information requested.
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McGuire Unit 1 Specific Relief Reauest RELIEF REQUEST: 1.4.2 -
PUMPS: 1FDPU0054,1 A D/G Fuel Oil Transfer Pump 1FDPU0055,1B D/G Fuel Oil Transfer Pump TEST REQUIREMENT: . Test pumps in accordance with OMa 1988 Part 6, Table 3b '
i BASIS FOR RELIEF: -The characteristics of these pumps and system configuration are such that the comparison of discharge pressure to the acceptance criteria in the code places the pumps in constant alert range.' Additionally, the flow rate evaluation is based on pump performance and derived such that the pump is not constantly in the alert range.
ALTERNATE TESTING: The D/G Fuel Oil Transfer Pumps are intemal gear positive displacement .
pumps. The performance curve for these pumps is relatively flat.
Capacity of these pumps is independent of discharge pressure when operating property and below the cracking pressure of the pump intemal relief valve. Since discharge pressure can be affected by the differential pressure of the filters downstream of the pumps and other normal ,
operating conditions associated with these pumps, discharge pressure will be monitored for information purposes, but it will not be compared to ;
any acceptance criteria. If the discharge pressure were to be compared to the acceptance criteria, due to the previously stated reasons, these pumps would be constantly in the alert range. Pumps will be tested by measuring level rise in the Fuel Oil Day Tank over time and converting the results to a flow in gallons per minute. This method provides a flow rate that meets the instrument accuracy requirements of 2 % (Table 1).
The test flow rate (O) will be compared to acceptance criteria established in accordance with Table 3b except the acceptable range has been -
widened on the high side and the High Alert Value has been increased.
As a result, the High Required Action Range has also been increased.
The increased acceptance enteria band is to allow for instrument fluctuations. The new limits are:
Acceptable Range: 0.94*Qr to 1.07*Qr Low Alert Range: 0.90*Qr to 0.94*Qr High Alert Range 1.07'Or to 1.10*Or l
Low Required Action Range: < 0.90*Or j I
High Required Action Range: > 1.10*Or !
11/1/93 SECTION 1.4 2 OF 11
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McGuire Unit 1 Specific Relief Reauest RELIEF REQUEST: 1.4.2 (Continued)
These pumps are designed to produce a flow rate of 22 gpm. The requirements of the Diesel Generator are approximately 6 gpm. Five vibration points are monitored and trended on the Fuel Oil Transfer Pumps. Acceptance enter.a for the vibration points is calculated based on Relief Request 1.3.1. Vibration data is trended on a quarterly basis similar to the flow test res alts. Any degradation in the performance of the Fuel Oil Transfer pumps will first appear in the vibration data. Also, the Fuel Oil Transfer pumps are conservatively designed in the discharge pressure that can be obtained. The capabilities of the pump are not challenged during the quarterly test with respect to discharge pressure.
System limitations restrict the discharge pressure to less than or equal to 55 psig; however, the Fuel Oil Transfer pumps could easily pump against 150 psig.
Since the pumps are installed with considerable safety margin with respect to flow and discharge pressure, the most prudent data to use for
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trending for pump degradation would be the velocity vibration data. By trending the five velocity vibration data points, the acceptability of the widened High Alert and Required Action ranges for flow are justified. The flow ensures system operability is met and the pump intemal relief valve is not lifting prematurely while the vibration test ensures an adequate trending program is in place to ensure continued operability during testing intervals.
The D/G Fuel Oil Storage Tank is the suction source for the Fuel Oil Transfer pumps and is monitored to maintain level as required by McGuire Technical Specifications. This level ensures adequate NPSH; therefore, a suction pressure reading is not required.
In addition, monthly Diesel Generator starting and loading (as required by i McGuire Technical Specifications) will assess the hydraulic condition of the subject auxiliary pumps and demonstrates the capability of the individual components to perform their design function.
11/1/93 SECTION 1.4 3 OF 11
NRC CONCERN REGARDING RELIEF REOUEST I.4.4 (TER SECTION 2.5.1):
Since The Licensee does have an instrumented minimum flow path, there is no basis for the licensee to record the pump flow rate .
for information purpose only. In addition, the licensee has not I provided any information specific to the RHR system to justify l waving the pressure instrument range requirements of IWP-4110 and i IWP-4120 for quarterly tests. !
With respect to the refueling tests, the licensee has not explained what is meant by the statement that the test method selected (i.e., testing the pump at a single point or utilizing a reference curve) will depend on plant refueling conditions and the quantity of pump data required.
Furthermore, the licensee has not stated the reason for
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requesting relief from the requirement of IWP-3100 concerning the l
variation of the system resistance until either the measured differential pressure or the measured flow rate equals the reference value. It is recommended that this relief request be denied pending further information from the licensee.
l t DUKE'S POSITION REGARDING RELIEF REOUEST I.4.4:
The-NRC reviewer expressed concerns regarding the recording of pump flow rate for information purposes only, and that specific information regarding the RHR system was not provided. In j addition, the request for relief from IWP-3100 was denied pending i further information from the licensee. IWP-3100 requires that the resistance of the system be varied until the measured differential pressure or the measured flow rate equals the corresponding reference value. This relief request has been modified to provide additional technical information specifically concerning the RHR pumps and has been updated to comply with the requirements specified by OM-6. The modified relief request was submitted to the NRC for review by a January 6, 1994 Duke Power i letter. The specific request for relief is provided in Section f I.4 of the McGuire Pump and Valve IST Program Manual for Unit 1 1 as Relief Request I.4.4. For convenience, Relief Request I.4.4 is i enclosed with this response.
I Briefly, the test loop (miniflow line) used in the test is 1 instrumented to measure flow. The system resistance cannot be l adjusted with the associated throttling valve without l invalidating the ND flow balance settings, as specified by Technical Specification 4.5.2h. As such, flow through this loop will be recorded for information only. A full-head curve test of these pumps will continue to be performed and reference a single point.
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McGuire Unit 1 Specific Relief Reauest f
! RELIEF REQUEST: 1.4.4 i
i PUMPS: 1NDPU0001,1 A Residual Heat Removal Pump i 1NDPU0002.1B Residual Heat Removal Pump l TEST REQUIREMENT: 1) OMa-1988 Part 6, Section 5.2.b requires the resistance of the system l to be varied until either the measured differential pressure or the measured flow rate equals the reference value.
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- 2) OMa-1988 Part 6, Section 4.6.1.2.a specifies the range of each j instrument shall be three times the reference value or less.
j BASIS FOR RELIEF: 1) When testing these pumps on line, the o' nly flow path available is through the miniflow control valve in the line, which yields a test point back on the head curve. As stated in Generic Letter 89-04, minimum flow
- lines are not designed for pump testing purposes. The test point for
- monitoring pump performance for degradation should be in a more stable region on the pump performance curve. Also, the amount of time the -
pump is run at miniflow should be minimized.
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- 2) Also, range requirements will be waived for the quarterly test. The purpose of the quarteriy is to verify Tech Spec requirements are met and to obtain vibration data for trending. The instrumentation used for the quarterly Residual Heat Removal Pump test will meet accuracy
, requirements for assuring Residual Heat Removal Pump operability per Technical Specifications.
ALTERNATE TESTING: The Residual Heat Removal Pumps will be tested according to the following prog:am, which is consistent with Generic Letter 89-04.
- Quarteriv The Residual Heat Removal Pumps will be tested quarterly to verify Technical Specifications are met. The test measures differential
.) pressure and velocity vibration data. The differential pressure and velocity vibration data will be trended. The instrumentation range -
requirements of OMa-1988 Part 6, Section 4.6.1.2.a will be waived. The instrumentation used to measure suction and discharge pressure will
- meet applicable accuracy requirements for the determination of operability per Technical Specifications. The instrument used to measure i vibrations will meet the requirements specified in relief request 1.3.1. The test loop used in the test has a flow measuring otifice installed, however, the system resistance cannot be adjusted with the associated throttling
, valve without invalidating the Residual Heat Removal system flow balance (a Tech Spec balance of flow to all 4 cold legs.) Therefore, flow through this loop will be recorded for information only.
4 11/1/93 SECTION l.4 5 OF 11 l
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l Specific Relief Reauest
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i RELIEF REQUEST: 1.4.4 (Continued)
Refuelina Outaae During each refueling outage, a code pump test - including velocity vibration measurements - will be performed at a test point in the stable ,
region of the performance curve.
As an attemative to repeat testing at-a single test point in the stable region, a reference curve may be obtained with applicable acceptance curves plotted. Using this technique, the full flow test point (also in the stable region of the pump curve) will be bound by flow points obtained in ;
the development of the reference curve. The data obtained is then evaluated against acceptance criteria and Chapter 15 basis acceptance .
curves to verify pump operability. When baseline vibration data varies significantly over the pump head curve, vibration acceptance criteria will be developed for flow regions of the head curve.
The test method selected will depend on plant refueling conditions, maintenance performed on the pump, and the quantity of pump data j required. Either method selected will ensure that the pump is tested in the full flow region of the head curve and that system operability is verified. Each test methodology is consistent with the intent of Code l requirements and Generic Letter 89-04, l
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11/1/93 SECTION 1.4 6 OF 11 I
NRC CONCERN REGARDING RELIEF REQUEST I.4.5 (TER SECTION 2.6.1):
Since the licensee does have an instrumented minimum flow path, there is no basis for the licensee to record the pump flow rate for information purpose only. In addition, the licensee has not provided any information specific to the Safety Injection system to justify waving the pressure instrument range requirements of i
IWP-4110 and IWP-4120 for quarterly tests.
With respect to the refueling tests, the licensee has not explained what is meant by the statement that the test method selected (i.e., testing the pump at a single point or utilizing a l
reference curve) will depend on plant refueling conditions and i the quantity of pump data required.
Furthermore, the licensee has not stated the reason for requesting relief from the requirement of IWP-3100 concerning the I
l variation of the system resistance until either the measured I differential pressure or the measured flow rate equals the reference value. It is recommended that this relief request be denied pending further information from the licensee.
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DUKE'S POSITION REGARDING RELIEF REOUEST I.4.5:
! The NRC reviewer expressed concerns regarding the recording of pump flow rate for information purposes only, and that specific information regarding the Safety injection system was not provided. In addition, the request for relief from IWP-3100 was denied pending further information from the licensee. IWP-3100 requires that the resistance of the system be varied until the measured differential pressure or the measured flow rate equals the corresponding reference value. This relief request has been modified to provide additional technical information specifically concerning the Safety Injection pumps and has been updated to comply with the requirements specified by OM-6. The modified relief request was submitted to the NRC for review by a January 6, 1994 Duke Power letter. The specific request for relief is provided in Section I.4 of the McGuire Pump and Valve IST Program Manual for Unit 1 as Relief Request I.4.5. For convenience, Relief Request I.4.5 is enclosed with this response.
Briefly, the test loop (miniflow line) used in the test is instrumented to measure flow. There is no means provided to vary the system resistance to set either the flow or differential pressure. As such, flow through this loop will be recorded for information only.
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e McGuire Unit 1 Epecific Relief Reauest RELIEF REQUEST: 1.4.5 PUMPS: 1 NIPU0009,1 A Safety injection Pump 1NIPU0010,1B Safety injection Pump i
TEST REQUIREMENT: 1) OMa-1988 Part 6, Section 5.2.b requires the resistance of the system I to be varied until either the measured differential pressure or the j , measured flow rate equals the reference value.
l 2) OMa 1988 Part 6, Section 4.6.1.2.a specifies the range of each 1 l instrument shall be three times the reference value or less. l l
l BASIS FOR RELIEF: 1) When testing these pumps on line, the only flow path available is through the miniflow line which has a flow restricting orifice. The orifice yields a test point back on the head curve. As stated in Generic Letter ,
89-04, minimum flow lines are not designed for pump testing purposes, j The test point for monitoring pump performance for degradation should l
- be in a more stable region on the pump performance curve. Also, the l
( amount of time the pump is run at miniflow should be minimized. ;
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- 2) Also, range requirements will be waived for the quarteriy test. The l purpose of the quarterly is to venfy Tech Spec requirements are met and to obtain vibration data for trending. The instrumentation used for the quarterly Safety injection Pump test will meet accuracy requirements for assuring Safety injection Pump operability per Technical Specifications.
ALTERNATE TESTING: The Safety injection Pumps will be tested according to the following program, which is consistent with ' *nenc Letter 89-04.
Quarteriv The Safety injection Pumps will be tested quarteriy to verify Technical Specifications are met. The test measures differential pressure and velocity vibration data. The differential pressure and velocity vibration data will be trended. The instrumentation range requirements of OMa-1988 Part 6, Section 4.6.1.2.a will be waived. The instrumentation used to measure suction and discharge pressure will meet applicable accuracy requirements for the determination of operability per Technical l Specifications. The instrument used to measure vibrations will meet the
, requirements specified in relief request 1.3.1. The test loop has a flow I measuring onfice installed, however, there is no means provided to vary the system resistance to set either the flow or differential pressure.
Therefore, flow through this loop will be recorded for information only.
11/1/93 SECTiON 1.4 7 OF 11
McGuire Unit 1 Soecific Relief Reauest RELIEF REQUEST: 1.4.5 (Continued)
Refuelino Outaae During each refueling outage, a code pump - including velocity vibration measurements - will be performed at a test point in the stable region of the performance curve.
As an attemative to repeat testing at a single test point in the stable region, a reference curve may be obtained with applicable acceptance curves plotted. Using this technique, the full flow test point (also in the stable region of the pump curve) will,be bound by flow points obtained in the development of the reference curve. The data obtained is then evaluated against acceptance criteria and Chapter 15 basis acceptance curves to venfy pump operability. When baseline vibration data varies ,
significantly over the pump head curve, vibration acceptance enteria will 1 be developed for flow regions of the head curve. j The test method selected will depend on plant refueling conditions, j maintenanca performed on the pump, and the quantity of pump data I required. Each method selected will ensure that the pump is tested in the full flow region of the head curve and that system operability is verified. l Each test methodology is consistent with the intent of Code requirements '
and Generic Letter 89-04.
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4 11/1/93 SECTION 1.4 8 OF 11
NRC CONCERN REGARDING RELIEF REQUEST I.4.6 (TER SECTION 2.7.1):
1 There is a flow element (1NVFE 6120) on the miniflow line leading from the charging pump 1A and a flow element (INVFE 6130) on the miniflow line leading from charging pump 1B. These flow elements are not instrumented for flow measurement.
The licensee's proposal to measure flowrate only during refueling j outages is approved pursuant to Generic Letter 89-04, Position 9.
The licensee should, however, consider instrumenting the flow elements in the minimum flow lines to allow testing in accordance with the Code. This could be a very minor modification.
1 The licensee has not provided any information specific to the CVCS Centrifugal Charging Pumps to justify waving the pressure instrument range requirements of IWP-4110 and IWP-4120 for quarterly tests. The licensee has not stated the reason for requesting relief from the requirement of IWP-3100 concerning the variation of the system resistance until either the measured differential pressure or the measured flow rate equals the reference value. It is recommended that this relief request be denied pending further information from the licensee.
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DUKE'S POSITION REGARDING RELIEF REOUEST I.4.6:
The NRC reviewer recommended that a modification to install flow measuring instrumentation be implemented and that additional i
information specific to the CVCS Centrifugal Charging Pumps be !
provided. In addition, the request for relief from IWP-3100 was denied pending further information from the licensee. IWP-3100 requires that the resistance of the system be varied until the measured differential pressure or the measured flow rate equals the corresponding reference value. This relief request has been modified to provide additional technical information specifically concerning the centrifugal charging pumps and has been updated to comply with the requirements specified by OM-6. The modified relief request was submitted to the NRC for review by a January 6, 1994 Duke Power letter. The specific request for relief is a provided in Section I.4 of the McGuire Pump and Valve IST Program Manual for Unit 1 as Relief Request I.4.6. For convenience, Relief Request I.4.6 is enclosed with this response.
Briefly, the test loop (miniflow line) used in the test is NOT instrumented to measure flow. In addition, there is no throttle valve or any other means provided to vary the system resistance.
Furthermore, a modification to install flow measuring instrumentation would not be cost effective and thus, is not a feasible option to pursue at this time.
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McGuire Unit 1 Soecific Relief Reauest J
RELIEF REQUEST: 1.4.6 PUMPS: 1NVPUOO15,1 A Centrifugal Charging Pump 1NVPUOO16,1B Centrifugal Charging Pump 1 TEST REQUIREMENT: 1) OMa-1988 Part 6, Section 5.2.b requires the resistance of the system to be varied until either the measured differential pressure or the measured flow rate equals the reference value.
- 2) OMa-1988 Part 6, Section 4.6.1.2.a specifies the range of each instrument shall be three times the reference value o.10ss.
BASIS FOR RELIEF: 1) When testing these pumps on lins, the only flow path available is through a combination of the normal charging line and the miniflow line to the Volume Control Tank. This test yields a test point back on the head
, curve. As stated in Generic Letter 89-04, the test point for monitoring pump performance for degradation should be in a more stable region on the pump performance curve. Also, the miniflow is not instrumented for flow. The flow through the line is assumed to be at the flow rate corresponding to the orifice design conditions.
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- 2) Also, range requirements will be waived for the quarterly test. The ;
purpose of the quarterly is to verify Tech Spec requirements are met and l to obtain vibration data for trending. The instrumentation used for the ;
quarterly Centrifugal Charging Pump test will meet accuracy l requirements for assuring Centnfugal Charging Pump operability per Technical Specifications.
ALTERNATE TESTING: The Centrifugal Charging Pumps will be tested according to the following program, which is consistent with Generic Letter 89-04.
Quarterly The Centrifugal Charging Pumps will be tested quarterly to verify Technical Specifications are met. The test measures differential pressure and velocity vibration data. The differential pressure and velocity vibration data will be trended. The instrumentation range requirements of0Ma-1988 Part 6 Section 4.6.1.2.a will be waived. The instrumentation used to measure suction and discharge pressure will meet applicable accuracy requirements for the determination of operability per Technical Specifications. The instrument used to measure vibrations will meet the requirements specified in relief request 1.3.1. The flow through the miniflow line to the Volume Control Tank will be assumed to be constant at the orifice design conditions (60 gpm).
11/1/93 SECTION 1.4 9 OF 11
McGuire Unit 1 l
i l Specific Relief Reauest REllEF REQUEST: 1.4.6 (Continued)
Refuelina Outace During each refueling outage, a code pump including velocity vibration measurements - will be performed at a test point in the stable region of
- the performance curve.
As an attemative to repeat testing at a single test point in the stable
, region, a reference curve may be obtained with applicable acceptance i curves plotted. Using this technique, the full flow test point (also in the stable region of the pump curve) will be bound by flow points obtained in the development of the reference curve. The data obtained is then evaluated against acceptance criteria and Chapter 15 basis acceptance curves to verify pump operability. When baseline vibration data varies l significantly over the pump head curve, vibration acceptance criteria will be developed for flow regions of the head curve. .
The test method selected will depend on plant refueling conditions, maintenance performed on the pump, and the quantity of pump data required. Each method however will ensure that the pump is tested in the full flow region of the head curve and that system operability is verified.
Each test methodology is consistent with the intent of Code requirements and Generic Letter 89-04.
I 11/1/93 SECTION l.4 10 OF 11
NRC CONCERN REGARDING RELIEF REOUEST I.4.7 (TER SECTION 2.8.1):
The licensee has not stated the reason for requesting relief from the requirement of IWP-3100 concerning the variation of the system resistance until either the measured differential pressure or the measured flow rate equals the reference value. It is recommended that the licensee's request to perform a " head curve" test upon completion of the modification be denied pending further information from the licensee.
Regarding testing the pump every two years, the licensee has not established the impracticality or burden of providing the required fluid inventory to permit testing quarterly in accordance with Section XI. The licensee's proposal to perform pump testing every two years complies with the requirements of OM-6 and relief is not required.
DUKE'S POSITION REGARDING RELIEF REQUEST I.4.7:
The request for relief from IWP-3100 was denied pending further information from the licensee. IWP-3100 requires that the l
resistance of the system be varied until the measured !
l differential pressure or the measured flow rate equals the I corresponding reference value. This relief request has been deleted. As recommended by the NRC reviewer, the Unit 1 IST program for the second ten-year interval has been updated to 1989-edition of Section XI. As such, these pumps will be tested in I accordance with OM-6 Code, which will include all related requirements. This has been documented within the McGuire Pump and Valve IST Program Manual for Unit 1, which was provided by a January 6, 1994 Dake Power letter. In addition, the testing will use the single point parameter comparison which complies with the OM-6 Code.
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i NRC CONCERN REGARDING RELIEF REQUEST GV-III (TER SECTION 3.1.1):
j The licensee has requested relief from the requirements of IWV-3417(a), which requires increasing the test frequency to once each month when valves exceed 25% or more form previous test (for valves with stork times > 10 sec.) or 50% form the previous
- test (for valves with stroke times $ 10 sec.). The licensee has not provided criteria for establishing limiting stork times. The licensee's proposed alternative is less restrictive than the industry developed OMa-1988 Part 10, without an explanation of l the burden or impracticality and how the proposed alternative provides reasonable assurance of the components operational readiness. If however, the licensee utilizes OMa-1988 Part 10 and all related requirements, relief would not be required.
l DUKE'S POSITION REGARDING RELIEF REQUEST GV-III This relief request was denied because information regarding the criteria utilized to establish the limiting stroke times was not provided. The NRC reviewer, however, recommended that the relief request would not be required if the Unit 1 IST program for the second ten-year interval is updated to OM-10 Code. This relief request has been deleted as a result of updating Unit 1 IST program. As recommended, the Unit 1 IST program plan has been updated to the OM-10 Code, including all related requirements of OM-10. This has been documented within the McGuire Pump and j Valve IST Program Manual for Unit 1, which was provided by a January 6, 1994 Duke Power letter. In addition, the limiting J values for each valve under the scope of OM-10 have been established. Accordingly, this relief is no longer required and ,
has been deleted. l t
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l NRC CONCERN REGARDING RELIEF REQUEST RR-VG1 (TER SECTION 3.12.1):
The licensee has stated that" Limitations on available acoustic equipment prevents its use on these valves" and that it would be burdensome to purchase additional acoustic monitoring equipment.
The previous SE stated that "in the event modifications are not effected in the 1993 refueling outages, the licensee must determine.if continued relief is required and submit a revised relief request prior to startup from the refueling outage. The proposed alternative is not adequate for long-term relief." The licensee has revised the request by rescheduling the modification to the next refueling outage, however, the licensee has not provided an explanation of the burden of utilizing acoustic equipment as requested in the previous SE. Therefore, without an expanded explanation of the burden of complying with the Code, relief cannot be recommended.
DUKE'S POSITION REGARDING RELIEF REOUEST RR-VG1:
! The NRC reviewer denied relief request RR-VGI because of inadequate justification of the burden associated with complying with the Code. The particularly concern expressed is that the licensee did not explain the burden associated with utilizing i acoustic equipment. As discussed in the initial relief request that was submitted by a Duke Power letter dated July 8, 1992, the valves in question were not initially included within the scope of our IST program. This oversight was identified as a result of our Design Basis Document upgrade program.
Direct observation of valve disk movement is not practical, since
- the valves in question are solenoid valves. One means, however, of indirect indication of valve disk movement is to use acoustic equipment. By use of this equipment, it is possible to i indirectly verify valve disk movement. Another means of indirect indication of valve disk movement was proposed within the initial relief request. As stated within the relief request, a diesel start test is performed every month. If any one of these valves fails to perform its intend function, it would result in a failure of the diesel to start. Conversely, a successful start of the diesel would indirectly indicate that the valve disk properly moved. As such, the proper movement of the valve disk is indirectly verified on at least a monthly basis.
The use of acoustic equipment to indirectly verify valve disk movement would still require a relief request and thus NRC approval. For our particular situation, another, equally affective, means of indirectly verifying valve movement was proposed. In fact, the proposed alternative testing would result in testing these valves on a more frequent basis (monthly instead of quarterly).
i Further, during the upcoming refueling outages (EOC-9 for both i units), the valves in question will be modified. The modification would result in deleting the valves from the scope of valves to be included within our IST program. For Unit 2, a revised relief request reflecting the revised schedule for completing the modification (EOC-9 refueling outage) was provided by a Duke Power letter dated August 24, 1993. The October 12, 1992 submittal provided the revised relief request which updated the Unit I revised schedule for completing the modification (E0C-9 refueling outage). Briefly, the reason for the delay in completing the modification is because of less diesel down time during the outage due to the increased concern with shutdown risk management. This revision will allow the modifications to be ,
planned within allowable outage windows.
As noted, NRC approval of this relief request was originally provided by a letter dated September 25, 1992. Within the September 25, 1992 letter, the NRC advised that a relief request be submitted in the event the modifications were not completed during the 1993 refueling outages for the two units. To this end, the October 12, 1992 IST program submittal for Unit 1 provided the request for relief for the Unit 1 valves, while for Unit 2 a relief request was submitted by an August 24, 1993 Duke ;
letter.
Accordingly, since there is an effective indirect means of !
monitoring the valve disk movement; and that in the near future :
! the valves will be modified in such a manner that they no longer i l fall within our IST program, continued interim relief until the
! EOC-9 refueling outages for both units is needed.
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