ML20035F978
| ML20035F978 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 04/19/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20035F977 | List: |
| References | |
| NUDOCS 9304230167 | |
| Download: ML20035F978 (7) | |
Text
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UNITED STATES.
ENCLOSURE f h sj NUCLEAR REGULATORY COMMISSION i(Xg8,
/
wAswmcTot o c. 20sss coci SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED T0 INSERVICE TESTING PROGRAM REllEF RE00ESTS NIAGARA M0 HAWK POWER CORPORATION NINE MILE POINT NUCLEAR STATION. UNIT 2 i
DOCKET NO. 50-410
1.0 INTRODUCTION
i The Code of Federal Regulations at 10 CFR 50.55a(f) requires that inservice testing (IST) of certain ASME Code Class 1, 2, and 3 pumps and valves be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda, except where relief has been requested by the i
licensee and granted by the Commission pursuant to Subsection (f)(6)(i) of i
10 CFR 50.55a or where an alternative is authorized by the Commission pursuant to Subsections (a)(3)(i) or (a)(3)(ii) of 10 CFR 50.55a.
In requesting relief or proposing an alternative, the licensee must demonstrate that:
(1) the proposed alternative (s) provide an acceptable level of quality and safety; (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety; or (3) conformance with certain requirements of the applicable Code Edition and addenda is impractical for its facility.
Section 50.55a(f)(4)(iv) provides that inservice tests of pumps and valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in 10 CFR 50.55a(b), subject to the limitations and modifications listed, and subject to Commission approval.
NRC guidance contained in Generic Letter (GL) 89-04, " Guidance on Developing Acceptable Inservice Testing Programs," provided alternatives to the Code requirements determined to be acceptable to the staff and authorized the use of the alternatives in Positions 1, 2, 6, 7, 9, and 10 provided that licensees fo: low the guidanea delineated in the applicable position. When an alternative is proposed which is in accordance with GL 89-04 guidance and is documented in the IST Program, no further evaluation is required; however, implementation of the alternative is subject to NRC inspection.
Furtherw re, in rulemaking to 10 CFR 50.55a effective September 8, 1992, (See 57 Fede al Reai C C 34666), the 1989 Edition of ASME Section XI was incorporated in 10 CFR 50.55a(b). The 1989 Edition provides that the rules for IST of pumps and valves may meet the requirements set forth in ASME Operations and Maintenance Standards Part 6 (OM-6), " Inservice Testing of i
Pumps in Light-Water Reactor Power Plants," and Part 10 (OM-10), " Inservice Testing of Valves in Light-Water Reactor Power Plants." Pursuant to Section i
50.55a(f)(4)(iv), portions of editions or addenda may be used provided that-all related requirements of the respective editions or addenda are met.
4 9304230167 930419 PDR ADOCK 05000410 p
! i Relief is, therefore, not required for those inservice tests that are conducted in accordance with OM-6 and OM-10, or portions thereof. Whether all related requirements are met is subject to NRC inspection.
I The Code of Federal Regulations at 10 CFR 50.55a authorizes the Commission to i
grant relief from or approve alternatives for ASME Code requirements upon
, making the necessary findings. The NRC staff's findings with respect tc i
granting or not granting the relief requested or authorizing the proposed alternative as part of the licensee's IST Program are contained in this safety i
evaluation (SE).
j This SE concerns relief requests that were submitted by Niagara Mohawk Power-Corporation (NMPC or the licensee) in a letter dated January 15, 1993, for the i
Nine Mile Point Nuclear Station, Unit 2, (NMP-2) IST program. These relief requests are evaluated below. The NMP-2 IST Program is based on the requirements of Section XI of the ASME Code, 1983 Edition through the Summer 1983 Addenda.
2.0 REllEF RE0 VEST EGF-PRR-1 i
t The licensee requested relief from the requirement listed in-Table IWP-3100-1 l
in Section XI of the AMSE Code to measure pump suction pressure for emergency diesel generator fuel oil transfer pumps 2EGF* PIA, 2EGF*PIB, 2EGF*Plc, 2EGF*PID, 2EGF*P2A, and 2EGF*P28. The licensee proposed to calculate the pump i
suction pressure.
i 2.1 Licensee's Basis for Reauestina Relief
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t The licensee stated that instrumentation is not installed for measuring fuel l
oil transfer pump suction pressure. NMPC also stated that the suction pressure can be calculated by measuring the difference in the fuel oil i
elevation in the storage tank and the transfer pump suction elevation. The difference is the suction pressure, in feet of head, which is then converted to pressure in pounds per square inch.
8 2.2 Alternate Testina 3
The licensee proposed to calculate suction pressure from the difference in elevation of the fuel oil and the pump suction inlet. NMPC stated that the calculated suction pressure meets the accuracy requirements of Table IWP-4110-1, as determined by an engineering evaluation.
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2.3 Evaluation j
i The six emergency diesel generator fuel oil transfer pumps used at NMP-2 are vertical turbine type pumps.
These pumps transfer fuel from the three j
underground fuel oil storage tanks to their respective fuel oil day tanks located near the three diesel generators.
The ASME Code requires measurement d
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of the pump inlet pressure in order to calculate pump differential pressure which is used to evaluate potential pump degradation. Due to the design of the pumps, inlet pressure cannot be measured directly.
The licensee has proposed to calculate pump inlet pressure by determining the difference in elevation between the level in the fuel oil storage tank and the pump inlet elevation and converting this value into-static pressure. The measuring of pump inlet pressure was deleted from the requirements of OM-6 because there were no acceptance criteria in the ASME Code.
The requirement exists in ASME Section XI, Subsection IWP, to assist the licensee in establishing the test and to recognize that adequate pump suction pressure should be available. The OM-6 Code recognized that the licensee is responsible for addressing testing limitations which will be written into their procedures.
l The licensee should proceduralize the calculation of inlet pressure and this l
calculation should meet the ASME Code accuracy requirements.
2.4 Conclusion l
Relief is no longer required for use of this portion of OM-6, pursuant to 10 CFR 50.55a(f)(4)(iv), provided the licensee implements all related requirements. Whether all related requirements are met is subject to NRC inspection.
i 3.0 RELIEF RE0 VEST SLS-PRR-2 i
The licensee requested relief from the requirements listed in Table IWP-3100-1 to measure pump suction pressure and differential pressure for standby liquid control (SLC) pumps 2SLS* PIA and 2SLS*PIB. The licensee proposed to measure pump discharge pressure and not measure pump suction pressure and differential pressure.
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3.1 Licensee's Basis for Recuestina Relief i
The licensee stated that pump suction pressure is the head of water in the i
test tank and test lines and that this pressure is constant during testing.
NMPC further stated that these positive displacement pumps are designed to-provide a constant quantity of fluid (flow rate) at a relatively high discharge pressure (approximately 1500 psig) regardless of the suction pressure.
In addition, the suction head is so small in comparison to the i
discharge pressure during testing of these pumps (2 psig vs. 1270 psig) that measurement of suction pressure would provide no useful information in assessing pump performance.
Similarly, calculation of pump differential pressure by subtracting suction pressure from discharge pressure also provides no useful information.
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i 3.2 Alternate Testina The licensee proposed to use pump discharge pressure, flow rate, and vibration in determining pump degradation.
i 3.3 Evaluation l
The two SLC pumps are designed to inject a neutron absorbing poison solution into the reactor vessel at maximum reactor pressure in the event that not enough control rods are inserted into the core to maintain the plant in a subcritical condition.
The ASME Code requires measurement of the pump inlet pressure in order to calculate pump differential pressure which is used to evaluate potential pump degradation. The SLC pumps are positive displacement pumps and their performance is not greatly effected by inlet pressure provided that pump net positive suction head requirements are met. There are currently no installed pressure indicators on the suction side of each pump.
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n The licensee has proposed to not measure pump inlet pressure because of the relatively large difference between the suction pressure (2 psig) and the discharge pressure (1270 psig) during SLC pump testing.
ASME Section XI, Table IWP-3100-.1, requires measurement of pump. inlet and differential pressure i
for both positive displacement. and centrifugal pumps. The measurement of pump i
inlet pressure was deleted from the requirements of OM-6 because there were no acceptance criteria in the ASME Code. The requirement exists in ASME Section XI, Subsection IWP, to assist the licensee in establishing the test and to recognize that adequate pump suction pressure should be available.
OM-6 recognized that the licensee is responsible for addressing testing limitations which will be written into their procedures.
In addition, since s
discharge pressure is independent of inlet pressure for positive displacement l
pumps, the requirement in OM-6, Table 2, has been changed to only require discharge pressure as the indicator of pump degradation for positive displacement pumps.
i 3.4 Conclusion l
i Relief is no longer required for use of this portion of OM-6, pursuant to 10 CFR 50.55a(f)(4)(iv), provided the licensee implements all related requirements including acceptance requirements for discharge pressure.
Whether all related requirements are met is subject to NRC inspection.
4.0 RELIEF RE0 VEST GpRR-3 The licensee requested relief from the ASME Code requirements listed in Table IWP-3100-1 to measure pump inlet pressure prior to pump start for the pumps l
listed below. The licensee has proposed to either calculate or measure the inlet pressures for each of these pumps during the test for determination of differential pressure.
s
v
-S-l l
High-Pressure Core Spray Pump 2CSH*P1 f
Low-Pressure Core Spray Pump 2CSL*P1 Diesel Fuel Oil Transfer Pumps 2EGF* PIA, 2EGF*PIB, 2EGF*PIC, 2EGF*PID 2EGF*P2A, 2EGF*P2B l
Reactor Core Isolation Cooling Pump 2ICS*P1 Residual Heat Removal Pumps 2RHS* PIA, 2RHS*PIB, 2RHS*Plc I
Fuel Pool Cooling Pumps 2SFC* PIA, 2SFC*PIB r
Service Water Pumps 2SWP* PIA 2SWP*PIB 2SWP*Plc 2SWP*PID l
2SWP* PIE 2SWP*PlF 4.1 Licensee's Basis for Reauestina Relief The licensee stated that these pumps use lake water, suppression pool or applicable tank contents as a fluid medium.
Lake water level will not change because of its large volume.
In those tests which use the suppression pool or tank as the fluid source, the fluid is recirculated back to the source to i
maintain level. Therefore, the change in supply pressure before a pump is started and throughout the duration of the test is negligible. The above levels are controlled either by plant technical specifications or other monitoring systems.
4.2 Alternate Testina I
The licensee proposed to measure or calculate inlet pressure only during the pump test. NMPC stated that the calculated inlet pressure meets the accuracy requirements of Table IWP-4110-1, as determined by an engineering evaluation.
4.3 Evaluation
+
l The pumps listed in this relief request are centrifugal type pumps with the exception of the emergency diesel fuel oil transfer pumps which are vertical turbine type centrifugal pumps. The licensee has proposed to not measure inlet pressure prior to pump start as required in ASME Section XI, Table IWP-3100-1. The measurement of pump inlet pressure prior to the start of the test was deleted from the requirements of OM-6.
The OM-6 Code recognized that adequate pump suction pressure should be available and that the licenser is responsible to address testing limitations which will be written into their precedures.
The licensee stated that inlet pressures were to be either calculated or measured during pump testing, but did not specify which pump inlet pressures l
would be calculated as opposed to measured. An examination of the Updated Safety Analysis Report figures related to the pumps discussed in this relief
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request revealed that all the pumps have pressure indicators on their suction sides with the exception of the diesel fuel' oil transfer pumps.
If the licensee uses a calculated inlet pressure to determine differential pressure, l
this is in compliance with IWP-4240 or Paragraph 4.6.2.2 of OM-6, provided the calculation method is included in the test procedure, provides accurate results, and is subject to a quality assurance review.
Conclusion l
Relief is no longer. required for use of this portion of OM-6, pursuant to 10 CFR 50.55a(f)(4){iv), provided the licensee implements all related requirements. Whether all related requirements are met is subject to NRC inspection.
e Principal Contributor:
l Joseph Colaccino j
Date: April 19, 1993-l
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Mr. B. Ralph Sylvia April 19,1993 This completes our efforts in response to the NMPC submittal dated January 15, 1993, and its associated TAC No. M85500.
1 Sincerely, I
i Original signed by:
I Robert A. Capra, Director Project Directorate I-l Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Enclosure Safety Evaluation of Relief Requests j
cc w/ enclosure.
p See next page I
, Distribution:
--Docket File --
J. Menning l
NRC & Local PDRs J. Colaccino, 7/E/23 i
PDI-l Reading OGC T. Murley/F. Miraglia,12/G/18 E. Jordan, MNBB 3701
}
J. Partlow,12/G/18 G. Hill (2)
E. Rossi, 9/A/2 ACRS (10)
J. Lieberman, 7/H/5 OPA i
S. Varga OC/LFDCB J. Calvo V. McCree, 17/G/21 R. A. Capra C. Cowgill, Region I C. Vogan
- See previous concurrence LA:PDI-l PM:PDI-I,
OGC D:PDI-l i
JMenning:hfI
- JHull RAcapra E' '
CVogan to Y/R/93 i/n/93 04/01/93 4 /19/93
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OfflCIAL RECORD COPY
- FILENAME: NM285500.REL T
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