ML20064B721
| ML20064B721 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 12/29/1982 |
| From: | Davidson D CLEVELAND ELECTRIC ILLUMINATING CO. |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8301040167 | |
| Download: ML20064B721 (19) | |
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' T H E C ! E V E L A N D F I F C I R ! C I L L lRi l N A T i l! G C O M P A N Y P.O. BOX 97 5 P ERRY, OHIO 44081 m TEL EPHON E (216) 259 3737 m ADDRESS-10 CENTER RO AD Serving The Best Location in the Nation December 29, 1982 Mr. B. J. Youngblood, Chief Licensing Branch No. I Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Perry Nuclear Power Plant Docket Nos. 50-440; 50-441 Seismic and Dynamic Qualifications of Mechanical and Electrical Equipment
Dear Mr. Youngblood:
This letter and its attachments provides our responses to the questions in Enclosure (1) to the letter dated February 26, 1982 from A. Schwencer to D. R. Davidson. These responses will be included in the next Amendment to the Perry FSAR.
If you have any questions, please contact me.
Very truly yours, Dalwy R. Davidson Senior Vice President DRD:kh cc:
J. Silberg, Esq.
J. Stefano M. Gildner tf D. Reif f O1 K. Matheny fi Attachments 8301040167 821229 PDR ADOCK 05000 A
i EQ-1 Section 3.9.3.'2 discusses hydrodynamic loads. What is meant by this?
Response
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" Hydrodynamic loads" is the term used for loads associated'with LOCA I
blowdown and SRV actuation due to the interaction of steam with air and water.
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EQ-2 Page 3.9-85, first paragraph - Indicate whether the reference to IEEE 323-1971 is correct and, if so, justify referencing this specification for performing a dynamic test.
Response
The reference on Page 3.9-85, first paragraph has been changed to IEEE 344-1971.
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i EQ-3 Describe how the valve's resonance frequencies are determined as part of the overall steamline analysis (Page 3.9-85, Last Paragraph.)
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Response
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The paragraph in question is revised to avoid any impression that the valve's resonance frequencies are determined as part of the overall steamline analysis.
The valve / actuator assembly modeling i
as part of the overall steamline analysis will automatically account for the natural frequencies of the assembly.
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hydrodynamic "g" load conditions. A dynamic test per Specification IEEE g
344-1971 shall be performed on the manifold assembly and the limit switch h
assemblies with shake table inputs equal to or exceeding those specified for the valve actuator.
i If the actuator assembly is found to have a natural frequency within the frequency range of the input response spectrum in either the valve open or valve closed position, the actuator assembly shall be dynamic load tested per the requirements of a or b.
1.
The actuator may be qualified for seismic including hydrodynamic loads requirements by shake table testing with the valve body.
If the actuator is to be tested with the valve body, the combination shall be secured to the shake table at the valve inlet and outlet. Other support to the combination is not allowed.
The shake table input shall equal or exceed those specified for the required response spectra. The actuator shall be cycled at each input condition and shall develop the designed force while operating within ~
the specified time limit.
2.
The actuator without tie valve loads may be qualified for seismic and hydrodynami6 load "reqt trements by shake table testing. The actuator I
shall be supported in a manner which simulates the actual valve body mounting and orientation. Stem seals and stem-to-cover clearances shall be duplicated on the test fixture. The shake table input shall equal or exceed those specified for the required response spectra.
The actuator shall be cycled at each input condition and develop the designed force while operating within the specified time limit.
In order to assure that design limits are not exceeded for both piping input i
loads and actuator dynamic loads, the MSIV is mathematically modeled in the main steam line system analysis. The valve's dynamic response (loads and accelerations) is based on the seismic / dynamic input to the main steam line n
piping system.
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3.9-85
Pipe anchors and restraints are provided in such a way as to limit the dynamic response and amplified accelerations to within design limits for n
the MSIVs.
The mathematical modeling of the assembly accounts for the h
natural frequencies of the assembly as determined by the analysis and confirmed by a generic test'.
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Main steam isolation valve operability following a downstream line break was demonstrated by the " state line test" as defined in the report APED-5750 (March 1969). The test specimen was a 20 inch valve of a design representative of the MSIVs. Operability during seismic and hydrodynamic accelerations is addressed in Section 3.9.2.2.1.
Environmental qualification of sensitive electrical / pneumatic equipment to meet performance requirements defined in Section 3.11 have been successfully completed by product design and test evaluation methods and are summarized as follows:
1.
Selection of materials and requirements of periodic replacements of environmentally affected materials assures performance during normal operation.
2.
Air valve test in 3400 F steam environment of design basis accident demonstrated performance of required function during abnormal plant operation.
The detailed qualification results are contained in General Electric Report VPF 2793-54-3.
3.9.3.2.3.1.2 Main Steam Safety / Relief Valves The S/R valves are qualified by test for operability during a seismic event.
Structural integrity of the configuration during a dynamic event is demonstrated i
by both code analysis and test.
a.
The valve is designed for maximum moments which may be imposed when installed in service.
These moments are resultants due to dead weight plus seiswie and hydrodynamic loadings on both valve and connecting pipe, thermal expansion of the connecting pipe, and reaction forces from valve discharge.
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EQ-4 Page 3.9-86, paragraph c. - Provide the criteria that was used to conclude that the 20-inch test valve is representative of the MSIVs.
Response
i The criteria used was to ensure that the test valve was similar in design and had the same operability considerations and characteristics.
For more detail, see APED 5750, " Design and Performance of GE BWR Main Steam Isolation Valves", March 1969.
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a IQ-5 Explain what is meant by a typical valve and provide the criteria used for selecting the test valve.
Describe what maximum capability load means? Also, indicate whether the valve and
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the actuator are tested together as an assembly.
Response
a A typical valve used for testing is one that is of the same configuration, material and construction as the actual valve that will be used.
The maximum capability load is the maximum load which when applied at the centerline of the actuator (holding the valve body rigid) will not affect the movement of the valve stem. Loads exceeding this value could cause stem galling or binding.
The actuator and valve are operability tested as an assembly.
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EQ-6 Page 3.9-89, first paragraph - Describe how acceptable vibration levels are determined.
Also, indicate if a qualified life is determined for all pumps.
Response
Vibration levels during in-shop tests are determined in accordance with the Guidelines of the Hydraulic Institute Standards or the Pump Manufacturer's Procedures.
Pump Manufacturer's Procedures are required to be within the requirements of the Hydraulic Institute Standards.
Maximum amplitude in mils is specified as a function of pump / motor RPM and is measured at the e.op motor bearing on vertical pumps, and on bearing housings for horizontal pumps.
A qualified life has not been specifically stated for pumps.
Pump life depends greatly on operating and maintenance procedures.
A maintenance program outlining scheduled replacement of sub-components such as bearings, seals, gaskets, and wear rings will be established.
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EQ-7 Page 3.9-98, paragraph above Test Procedure A: - Provide the criteria used to select the test valve, including what is meant by "...most conservative construction."
Response
Test valves are selected from each group of valves having geometric similarity.
Generally this requires that the valve body castings and motor operator models be identical to the tested prototype in order to show proof of similarity.
Some valve manufacturers have tested only the largest valves in groups where they are geometrically similar, but of different size ranges.
The manufacturer's justification for only testing the larger of the series of size ranges is that the smaller valves are always more rigid and can accept higher 'g' loads.
The most conservative construction is usually the larger of the valves in a group with geometric similarity.
Where motor operators are mounted on valves, the most conservative construction is usually the valve with the largest operator to valve weight ratio.
This generally results in the smaller valves being tested since the operator to valve weight ratio increases for the smaller sizes.
EQ-8 Page 3.9-100, Test Procedure C: - Describe how the strains in critical component parts were determined.
Also, clarify why more than one plant loading condition was simulated if each is larger than the combined.
Response
The strains in critical component parts are determined by performing a static structural analysis of the valve under equivalent static forces conservatively representing the actual dynamic loadings.
Seismic forces on each critical component are obtained by concentrating its mass at its center of gravity and multiplying by the appropriate seismic load factors.
Load combinations include (1) seismic loads, (2) design pressure, and (3) piping reaction forces.
Test procedure e states that the calculated strains in critical components were greater for each loading case than the actual strains during combined plant loading.
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EQ-9 Page 3.9-101, Subsection 3.9.3.2.4.2.1 - Clarify what is meant by appropriate seismic qualification standards.
Response
Appropriate seismic qualification standards are in accordance with t
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EQ-10 Page 3.9-101, Subsection 3.9.3.2.4.2.2 - Indicate whether the check valve's internals are included in the stress analysis model. Also, indicate whether and how a qualified life is determined for these internal components.
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Response
Valve internals as listed on page 3.9-10lb Am. 1 were included in the stress analysis model.
Qualified life for these internal components is most realistically determined by operating surveillance and established maintenance schedules.
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EQ-ll Page 3.9-102, Subsection 3.9.3.2.4.2.3 - Briefly describe how -
the test valves were proven to be dynamically equivalent to the valves supplied by Target Rock.
Response
The analysis indicate that all of the dynamic characteristics such as natural frequency of each group are similar.
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EQ-12 Tables 3.10-1 and 3.10-2, pages 3.10-17 through 3.10-63, of the FSAR on Seismic Category I Instrumentation and Electrical Equipment and Supports Identification and Seismic and llydrodynamic Load Qualification Summary and Balance of Plant Category I Electrical and Instrumentations Equipment Qualification Results, respectively, are not complete. On what date will complete Tables 3.10-1 and 3.10-2 be submitted to the NRC?
Response
Tables 3.10-1 and 3.10-2, pages 3.10-17 through 3.10-63 have been deleted.
Section 3.10 contains information concerning the seismic qualification program. The device specific information will be provided under separate cover to support the plant site audit review teams of the NRC - Equipment Qualification Branch.
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EQ-13 For plants for which the CP application was docketed af ter October 27, 1972, the qualification of electrical equipment and their supports must meet the requirements and recommendations of the IEEE Standard 344-1975 and the Regulatory Position of Regulatory Guide 1.100, which endorses IEEE Standard 344-1975.
These documents are generally applicable to all types of equipment and should be used to the extent practicable for the qualification of mechanical equipment as well.
Do you plan to commit to IEEE Standard 344-1975 for both NSSS and BOP equipment?
If not, what are the exceptions and the justification for these exceptions?
Response
Exceptions to IEEE Standard 344-1975 will be identified on a case by case basis by a seismic qualification review effort as described in Section 3.10.1.1.3.4.
Justifications will be provided to demonstrate that exceptions have no significant safety impact.
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EQ-14 In qualification by analysis and testing justify the selected (3.10) values of 1, 2, 4, and 7 percent of the critical damping ratio as stated in Section 3.10.2.1.2 of the FSAR, Page 3.10-4.
Are the damping values known or are the damping values assumed?
Do you plan to commit to Regulatory Guide 1.61 for damping values?
Response
The critical damping ratios for piping, mechanical equipment and structures chosen to bound the values given in Regulatory Guide 1.61 and to were facilitate interpolation for purposes of performing a response spectrum analysis.
The damping values are selected as shown in Table 3.7-1.
Section 3.10.2.1.2 has been revised to delete references to damping factors.
Section 3.10.1.1.3.1 has added a commitment to RG 1.61.
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EQ-15 In Section 3.10.2.1.3.1, page 3.10-5, of the FSAR the higher cut-off frequency for combined seismic and hydrodynamic loads is not stated.
What is the numerical value of the higher cut-off frequency?
Response
The cut-off frequency for combined seismic and hydrodynamic loads is 60 Hz.for NSSS equipment testing and 100 Hz for BOP equipment testing.
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EQ-16 The statement "if the fundamental frequency of the equipment is above the input excitation frequency, the equipment is considered rigid" appears in Section 3.10.2.2, page 3.10-8, of the FSAR.
For equipment with resonant frequencies below 33 Hz and between 33 Hz and the higher cut-off frequency, is the above statement applicable?
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Response
The above statement is applicable for equipment with resonant frequencies below 33 Hz and between 33 Hz and the higher cut-off frequency.
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