ML20118A591
| ML20118A591 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 09/17/1992 |
| From: | NIAGARA MOHAWK POWER CORP. |
| To: | |
| Shared Package | |
| ML20118A589 | List: |
| References | |
| NUDOCS 9209240007 | |
| Download: ML20118A591 (7) | |
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ATTACl! MENT A NIAGARA moi!AWK POWER CORPORATION DOCKET NO. 50-410 NPF-69 Proposed Chanaes to the Technical Specificatione Replace existing pages 3/4 3-72 and 3/4 3-73 with the attached revised pages.
These pages have been retyped in their entirety with marginal markings to indicate changes to the text.
1 9209240007 920917 rDR ADOCK 05000410 P -.
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. TABLE 3.3.7.21 fiEISMIC MONITORING INSTRUMENTATIOR MINIMUM MEASUREMENT INSTRUMENTS INSTRUMENTS AND SENSOR LOCATION $
RANGE OPERABLE 1.
Triaxial Time-History Accelerographs and Trigger a.
Reactor Bldg. Mat El.175'-0" 0 1 1.0 g 1
b.
Reactor Bldg. Refueling Floor El. 353'-10" 0
1.0 g 1
c.
Control Bldg. Mat. El. 214'-0" 0 1 1.0 g 1
2.
Triaxial Peak Accelerographs a.
Diesel Generator Bldg. Service 0-5 g' 1
Water Piping b.
Prim. Cont. High Pr. Core Spray Piping 0 10 g
- 1 c.
Prim. Cont. Reactor Pedestal 0-10 g' 1
l 3.
Triaxial Soismic Switches Reactor Bldg. Mat. El.175'-0" 0.025-0.25 g 1**
(Adjustable) 4.
Triaxial Response-Spectrum Recorders a.
Reactor Bldg. Mat. El.175'-0" 0
- 2 g' 1**
b.
Prim Cont. RHR Piping Pene. El. 294'-6" O i 2 g' 1
c.
Reactor Bldg. Refueling Fl. El. 353'-10" 0
- 2 g*
1 d.
Control Bldg. Mat. El. 214'-0" 0 i 2 g* ~
1 i
Calibration required to be for the range:
1 g.
With control room annunciation.
NINE MILE POINT - UNIT 2 3/4 3-72 Amendment No.
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TABLE 4.3.7.2-1 SEISMIC MONITORING.INSTRt) MENTATION SURVEILL_ANCE REQUIREMENTS CHANNEL CHANNEL FUNCTIONAL CHANNEL INSTRUMENTS AND SENSOR LOCATIONS CHECK TEST CAllBRATION 1.
Triaxial Time-History Accelerographs and Trigger
- a. Reactor Bldg. Mat. El.175'-0" M*
SA R
- b. Reactor Bldg. Refueling Fl. El. 353' 10" M*
SA R
- c. Control Bldg. Mat. El. 214'-0" M*
SA R
2.
Triaxial Peak Accelerographs
- a. Diesel Gen. Bldg. Service Water Piping NA NA R**
- b. Prim. C ;nt. High Pr. Core Spray Piping NA NA R**
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- c. Prim. Cont. Reactor Pedestal NA NA R**
l 3.
Triaxial Seismic Switches Reactor Bldg. Mat. El.175'-0" M***
SA R
4.
Triaxial Response-Spectrum Recorders
- a. Reactor Bldg. Mat. El 175'-0" M
SA R**
- 5. Prim Cont RHR Piping Pene. El. 294'-6" NA NA R**
- c. Reactor Bldg. Refueling Fl. El. 353'-10" NA NA R**
- d. Control Bldg. Mat El. 214'-0" NA NA R**
Battery and Tr!gger only.
Calibration required to be for the range: 1 1 g.
Except seismic trigger.
NINE MILE POINT - UNIT 2 3/4 3-73 Amendment No.
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Page 1 of 4 ATTACHMENT B NIAGARA HOHAWK POWER CORPORATION DOCKET No. 50-410 NPF DESCRIPTION OF PROPQ1ED TECHNICAL SPECIFICATION CHANCES Niagara Mohawk Power Corporation (NMPC) propost the following changes:
1)
Item 2.c of the Instruments and Sensor Locations of Technical Specification Tables 3.3.7.2-1 and 4.3.7.2-1, currently states:
" Prim. Cont. P.ecire. Pump Motor" NMPC proposes to modify item 2.c to states
" Prim. Cont. Reactor Pedestal" d
gAFETY EVALUATIOE The operability of the seismic mcnitoring instrumentation ensures that sufficient l
capability is available to promptly determine the ground motion effects of a seismic event and evaluate the response of those features important to safety.
This capability is j
required to permit comparison of the measured response to that used in the design basis for the plant.
The above cha nges reflect relocation of tne triaxial peak accelerograph, from the constant vibration environment of the Recirculation Pump Motor, to the lower background vibration environment of the reactor pedestal.
This. change is necessary to ensure that the sensitive instrument's response to actual seismic activity is not masked by the background vibration readings occurring at the instrument's original location on a large pump motor.
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The new location on the reactor pedestal complies with Regulatory Guide 1.12 and American National Standard ANS 2.2 and will improve the instrument's ability to provide accurate measurements of seismic response.
This instrument is a passive, non-safety related instrumente requiring no electrical power to operate.
Inasmuch as it does not control or actuate any systems and its failure would not inhibit the function of any safety related systems or components, its relocatien does not alter or affect-the operation of any safety related. equipment or the safe operation or shutdown of the plant. Moreover, its relocation increases its ability to provide accurate measurements of seismic response in accordance with the level of information required by the Technical Sre ifications and the USAR.
For these reasons, there is reasonable assurance that the instrument relocation that would be authorized by the proposed amendment, will not endanger the health and safety of the public.
SUPPORTING INFORMATION American National Standard " Earthquake Instrumentation Criteria for Nuclear Power Plants" ANSI /ANS 2.2 and Regula sry Guide 1.12, Rev. 01,-" Instrumentation for Earthquakes" provide types.of-instruments to enable the licensee to make administrative decisions or invoke administrative procedures following an earthquake.
Information from these instruments will be used to determine the conservatism in design assumptions for the structure and the design input motion to supported systems and components. This information will further;be used to assess whether a safety evaluation is required for continued operation following an earthquake, j
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1 Page 2 of 4 The seismic Instrumentation System of Nine Mile Point Unit 2 includes instruments tot record the time history vibratory motion, record points en a response spectrum, provide immediate remote indication that a specified acceleration has been exceeded, provide
.immediate remote indication that specified spectral accelerations have been exceeded, and record peak acceleration by non-powered, passive instruments.
The records of peak acceleration by non-powered, passive instrumente called triaxial peak accelerographs are to be used following an earthquake to determine if continued operation without a safety analysis is advisable.
This Application for Amendment proposes a relocation of one triaxial peak accelerograph.
The accelerograph relocction is nececeary to avoid high background vibration at the l
original instrument location which could mask readings from actual seismic activity, i
In a Special Report dated January 16, 1989, Niagara Mohawk advised toe NRC that Triaxial a
Peak Accelerograph 2ERS-PAC 2C on the reactor recirculation pump motor was declared inoperable as a result of a failed vertical channel flexure arm, vertical permanent record plate indications exceeding amplitude values expected in an earthquake, and a loss of transverse axial sensitivity.
Subsequent testing and analysis by Engineering revealed that the normal, but constant vertical vibration of the pump motor loosened the flexure arm and caused it to fail.
The loosened arm recorded increased amplitude on the record plate. Constant instrument wear caused degraded sensitivity of the transverse platform sensor asaembly.
Niagara Mohawk, in the January 16, 1989 Special Report, committed to move the instrument to a location with an acceptably low level of background vibration. A Safety Evaluation was performed according to 10 CFR 50.59, and-the prnposed location reported to the Nuclear Regulatory Commission by Special Report dated July 9, 1990.
As described in the July 9, 1990 Special Report,. surveillance tests were planned for the Unit's second refueling outage to evaluate whether the background vibration at the new location.had been acceptable, i
Triaxial peak accelerograph 2ERS-PAC 2C was relocated to the, reactor pedestal _during the unit's first refueling outage in the autumn of 1990.
Surveillance teste conducted during i
a forced outage in April 1991, a brief surveillance outage in August 1991, and the second refueling outage in 1992 recorded acceptably low background vibration values. These-values were below those expected from an Operating Basis Earthquake and demonstrated that the accelerograph could distinguish background noise from seismic activity at its new 1
location on tne-reactor pedestal. The reactor pedestal, therefore, is an acceptable permanent location for triaxial peak accelerograph 2ERS-PAC 2C.
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Page 3 of-4 NO SIGNIFICANT HAZARDS CONSIDERATION.ANALYSlS s
According to 10CFR50.91, at the time a licensee requests an amendment, it must provide to the Commission its analysis, using the standards in 10CFR50.92, concerning the issue of no significant hazards consideration.
According to 10CFR50.92(c), a proposed amendment to an operating license involves no significant hazards considerations if operation of the facility in accordance with the proposed amendment would not:
1.
Involve a significant increase in the probability or consequences of nn j
accident previously evaluated; or 2.
Create the possibility of a new or different kind of accident from any accident previously evaluated; or 3.
Involve a significant reduction in a margin of safety.
4 Niagara Mohawk has evaluated this proposed amendment pursuant to 10CFR50.91 and has determined that it involvea no significant hazards considerations.
The following analysis has been performed.
The operation of Nine Mile Point Unit 2, in accordaDre with the nyrppsed_ amendment, will not involve a siunificant increase in the probability or consecuences of an accident oreviously evaluated.
This Amendment relocates a nor.-safety related passive instrument.
The relocated inatrument is a triaxial peak accelerograph which has been moved from the reactor racirculation pump "A" motor to the reactor pedestal, azimuth 137.5* at elevati.on 265' 5 1/2".
The new location on the reactor pedestal complies with Regulatory Guide 1.12 and American National Standard ANS 2.2 and will improve the jnstrument's ability to provide accurate measurements of seismic response.
This non-safety related passive instrument does not control or actuate any systems.
It does not perform an active function in response to an accicent analyzed in the Updated Safety Analysis Report (USAR).
The triaxial peak accelerograph will, however, measure the maximum acceleration response of reactor equipment during a seismic event.
This i
information will enable Niagara Mohawk to compare the seismic response of reactor equipment with the design basis described in 6ection 3.7 of the USAR.
4 The relocation of triaxial peak accelerograph 2ERS-PAC 2C by this Amendment will not increase the probability or consequences of any accidents previously evaluated.
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Page 4 of 4 The ooeration of Nine Mile Jbqiut Unit 2, in accordance with the proposed qmgndment, will not create the possibility of a new or different kind of accident from any accident nreviousiv evaluated.
This instrument is a passive, non-safety related instrument, requiring no electrical power. The instrument does not control or actuate any systems and its failure would not inhibit the function or any safety related systems or components.
Its relocation will not i
alter or affect the operation of any safety related equipment or the safe operation or shutdown of the plant.
The relocation of triaxial peak accelerograph 2ERS-PAC 2C has no effect on pipe breaks and jet impingecc.ont on systems within the containment.
This instrumen' 'elocation does not create any new human factors or fire protection concerns, nor does.c affect any equipment clearance or any existing heavy loads analysis, d
In summary, the relocation of triaxial peak accelerograph 2ERS-PAC 2C does not create the possibility of a new or different kind of accident from any previously evaluated.
The operation of Nine Mile Point Unit 2.
in accordance with the proposed amendment, will not involve a sianificant reduction in a marcin of safety, c
The relocation of 2ERS-PAC 2C will increase its ability to provide accurate measurements of seismic response in accordance with the level of information required by tho Technical Specifications and the USAR.
This information may be required,.according_to Regulatory Guide 1.lf, to determine "the advisability of continuing the-operation of the plant without a safety analysis following an earthquake."
This relocatud triaxial peak accelerograph does not affect, control, or actuate any safety related systems or any systems required for the sai'o operation or' shutdown of the plant.
Consequently, this Amandment'to relocate triaxial peak accelerograph 2ERS-PAC 2C does not involve a reduction in a margin of safety, i
Accordingly, as determined by the analysis above, this proposed Amendment involves no
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significant hazards consideration.
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