ML20211B937
| ML20211B937 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 08/18/1999 |
| From: | Abbott R NIAGARA MOHAWK POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR NMP1L-1454, NUDOCS 9908250125 | |
| Download: ML20211B937 (34) | |
Text
i Niagara @ Mohawk' Richard 5.M Phone; 315.349.1812 Vice President Fax: 315.349 4417 NuclearEngineering August 18, 1999 NMPIL 1454 i
U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 RE: Nine Mile Point Unit 1 Docket No. 50-220 DPR-63
Subject:
Generic Implementation Prvcedure (GIP) Method A for Resolution of USI A-46.
Gentlemen:
The purpose of this letter is to provide additional information regarding the application of Method A at Nine Mile Point Unit 1 (NMPI) as described in the Generic Implementation Procedure, Revision 2 (GIP-2), the NRC's Supplemental Safety Evaluation Report No. 2 (SSER No. 2), and the documents referenced in GIP-2 upon which GIP-2 is based. This information was requested in a telephone conference between the NRC and Niagara Mohawk Power Corporation (NMPC) representatives on October 14,1998.
As indicated in our letter dated September 18,1992, NMPC used Method A to estimate seismic demand for certain equipment within 40 feet of effective grade at NMP1. During discussions with NMPC, the NRC questioned our use of Method A when the amplification l factor between the free-field ground response spectrum (GRS) and the calculated in-structure response spectra (ISRS) was more than 1.5. The NRC referenced the language on page 4-16 l of the GIP which states that "the amplification factor between the free-field response spectra l and the in-structure response spectra will not be more than about 1.5 . . ."
NMPC has determined that the approach described in our September 18,1992 submittal for I
(
applying and implementing GIP Method A for resolution of the USI A-46 program is !
appropriate and technicallyjustified based on the following:
- - NMPC's interpretation of GIP-2 rules for use of Method A is correct and l implementation of Method A was proper. The detailed bases for this assertion are provided in Enclosure 1 to this letter.
Y"/ 9((
...,l0-'~
9900250125 990818 PDR ADOCK0500g0 P
Nine Mile Point Nuclear Station RO. Box 63, Lycoming, New York 13093-0063
- www.nimo.com
Page 2
exceed 1.5 times the ground response spectra (GRS). However, these spectra were generated using conservative methods and assumptions (typical of most nuclear plant
. response analyses) which artificially increase the amplifications over those which would be expected in an actual earthquake. Further, the expected differences between calculated and actual building response do not represent a significant safety issue for resolution of USI A-46. The detailed bases for this position are given in Enclosure 2 to this letter.
Based on the above, and the information in Enclosures 1 and 2, NMPC concludes we have properly interpreted the conditions on use of Method A of GIP-2. This conclusion is also based on the understanding that these conditions had been previously accepted by the NRC staff. To change this interpretation at this stage in the program for resolution of A-46 would be inconsistent with the spirit and intent of A-46 and would also require rework of equipment or additional analyses and evaluations without a commensurate safety benefit. NMPC completed resolution of GIP-2 outliers related to USI A-46 during Refueling Outage No.15.
Sincerely, ,
/d - .
)
Richard B. Abbott Vice President Nuclear Engineering i
RBA/JMT/ kap Enclosures (2) xc: Mr. H. J. Miller, NRC Regional Administrator Mr. S. S. Bajwa, Section Chief PD-1, Section 1, NRR Mr. G. K. Hunegs, NRC Senior Resident Inspector Mr. D. S. Hood, Senior Project Manager, NRR Records Management j
$ 44 ENCIDSURE 1 RASES FOR INTERPRETATION AND IMPLEMENTATION OF GIP-2 RULES FDR METHOD A NMPC has determined that the approach described in our September 18,1992 submittal for applying and implementing GIP Method A for resolution of the USI A-46 program is appropriate and technically justified. The bases for this conclusion are listed below:
- 1. SQUG and NMPC Interpretation of the GIP The caution given on page 4-16 of GIP-2 lists two limitations on use of Method A:
- Equiprnent should be mounted in the nuclear plant below about 40 feet above the effective grade, and
- Equipment should have a fundamental natural frequency greater than about 8 Hz.
The introductory wording in GIP-2 for these two limitations provides the bases or purposes for imposing them, namely (1) to limit amplification to no more than about 1.5 and (2) to avoid the high-energy frequency range of earthquakes. The specific limitations which are intended by the SQUG/NRC expert panel Senior Seismic Review and Advisory Panel (SSRAP) and SQUG to satisfy these bases are included in the two bulleted items listed above. The statement on page 4-16 that the amplification will not exceed about 1.5 is the expected result of meeting the above limitations, not a third condition.
A comparison of Method A amplification with that of calculated in-structure response spectra (ISRS) was never intended. In fact, the context of the caution on page 4-16 of GIP-2 makes clear that the advantage of Method A is that equipment meeting the two bulleted limitations above "can be evaluated without the need for using in-structure
_ response spectra . . ."
- 2. The Intent of the GIP is Clear and Consistent with SSRAP's Position
- The GIP-2 (page 4-11) cites the SSRAP report as the basis for the Bounding '
Spectrum which is used in Method A, and requires users to read and understand it.
The SSRAP report clearly explains the limitations and conditions which appear on page 4-16 of the GIP. SSRAP's report states:
"Thus, it is SSRAP's judgment that amplifications greater than a factor of 1.5 are unlikely in stiff structures at elevations less than 40 feet above grade .
except possibly at the fundamental frequency of the building where higher I amplifications occur when such a frequency is less than about 6 Hz. Thus, for equipment with fundamental frequencies greater than about 8 Hz in the as-anchored condition it was judged that floor spectral amplifications within 40 feet of grade would be less than 1.5 when reasonably computed using .
more median centered approaches."
[SSRP Report, Page 102] i 1
The SSRAP Chairman and dev: loper of Method A, Dr. Robert Kennedy, was contacted by SQUG and concurs with the interpretation given in Item 1 above.
- On June 5,1997, the NRC requested additional information regarding verification of seismic adequacy of mechanical and electrical equipment. Question 7.a asked to identify structure (s) having an in-structure response spectra (ISRS) (5 percent of critical damping) for elevations within 40 feet above the effective grade that are higher in amplitude than 1.5 time the SQUG bounding spectra. As stated in letter NMPIL 1238, elevation 259' of the Reactor Building is the only elevation that contains safe shutdown equipment to be evaluated per the GIP having an ISRS for elevations within 40 feet above the effective grade that are higher in amplitude than 1.5 times the SQUG bounding spectra.
The exceedance of the Reactor Building 259' ISRS versus the 1.5 x Bounding Spectra (1.5BS) occurs at two ranges of frequencies. The first range occurs at the high-energy frequencies of 4-8 Hz. The peak ISRS in the north-south direction, at 1.24g, is about at the 1.5BS peak of 1.2g. The east-west ISRS is at the peak of the 1.5BS. Based on this assessment, the GIP is met because the ISRS is at or about the 1.5BS.
The second exceedance occurs at the lower energy frequency range of 14-18 Hz.
The peak north-south ISRS of 1.12g is about 4 times the 1.5BS. The peak east-west ISRS of 0.77g is about 1.2 times the 1.5BS. Since the exceedance is at the lower energy frequencies and the ISRS is below the 1.5BS peak, the intent of the i GIP is also met at the lower energy frequency range of 14-18 Hz. I
- 3. NRC Pacitinn Regarding GIP-2 Method A
- The NRC backfit analysis in NUREG-1211, which justifies implementation of the USI A-46 program by affected licensees, relies on the conclusions reached by SSRAP in their review of seismic experience data. NUREG-1211 states the following:
"The NRC staff has closely followed the SSRAP work and is in broad agreement with its conclusions. The staff has concluded that if the SSRAP spectral conditions are met, it is generally unnecessary to perform explicit seismic qualification on the eight' classes of equipment studied."
[NUREG-1211, page 17]
'The eight classes of equipment cited in NUREG-121I were later expanded to 20 equipment classes.
2 l
Note that this quotation specifically makes reference to the SSRAP " spectral conditions." The spectral conditions are described in SQUG's position given above
.. . and were included in GIP-2.
- - The use of Method A was previously reviewed and accepted by the NRC and SSRAP representatives during two pilot plant reviews conducted in 1987 and 1988.
These reviews are documented in GIP-2, References 16 and 25. The specific material presented to the NRC representatives on use of Method A is described in the report of the BWR pilot review as shown in Attachment A to this Enclosure.
The seismic demand criteria described during this trial plant review are the same as described in item 1 above. NRC and SSRAP representatives did not raise objections to the approach used by SQUG in conducting these trial plant reviews.
t The topics discussed with and comments made by NRC and SSRAP representatives during the BWR pilot review are included in Attachment B to this Enclosure.
During this trial plant review, seismic demand information was discussed in detail.
- The NMPC/SQUG interpretation of the rules for applying Method A is also consistent with the SQUG training course on use of the GIP methods provided to utility and NRC personnel. Attachment C to this Enclosure is an excerpt from the L class notes used during this course. Slide 26, Screen #2, shows several screening methods for comparing equipment capacity to demand. Screen #2 illustrates uses of
! GIP Method A as described in item 1 above. For example, if equipment is below 40 feet and above 8 Hz, and the Bounding Spectrum envelopes the ground response j
- spectrum, the equipment is acceptable, j
- 4. NRC Internr entl= Rendars Method A Not Useful The NRC interpretation is that Method A can be used only when calculated ISRS are less than 1.5 x GRS. This interpretation negates the value of using Method A. Specifically, Method A could only be used when it produces higher seismic demand than Method B where calculated ISRS are used. Under this interpretation, Method A would not be used.
l 1
i 3
i
ATTACHMENT A Excerpt from GIP-2, Reference 25 Results of BWR Trial Plant Review l
Seismic Demand Criteria I
t SEISMIC DEMAND CRITIERIA APPLICATION DEMAND CRITIERIA
- 1. Equipment in experience data 1. Compare ground spectra with base and less than AO' above bounding spectrum (Figure 3.1 l- 243', and fundamental frequency in SSRAP report).
greater than 8 Hz.
- 2. Equipment in experience data 2. Compare amplified floor base over 40' above 243' (cver response spectra with 1.5 x 281' elevation) or fundamental bounding spectrum (Figure I frequency less than 8 Hz. R1, . . . Rn , T1, . . . . Tn ) .
Equipment covered by GERS (any 3. Compare amplified floor spectra l 3.
elevation, frequency). (median-centered) with 2/3 x GERS for specific equipment class.
l 4 Anchorage evaluation and 4.
equipment-specific stress I checks (excluding valves):
- Equipment within 40' of - Utilize accelerations from
" grade" (elevation 281' and (1.5 x ground spectra) x I below) and fundamental 1. 25 .-
frequency less than 8 Hz.
- Equipment at any elevation. - Utilize accelerations from median-centered amplified floor response spectra x I 1.25.
- Equivalent static load factor - Using appropriate spectra 1 for all equipment (except with multiplier, use:
valves).
- Peak acceleration for flexible equipment.
l - ZPA for rigid equipment.
- Acceleration at calculated fundamental frequency.
- Static load check for valve - 3G, Weak direction.
I operator / yoke checks.
I *No te: In general, for equipment with fundamental frequency greater than 8 Hz and within 40' of grade,1.5 x ground spectra may be used as an estimate of median-centered amplifled floor response spectra.
l l -
ATTACHMENT B Excerpt from GIP-2, Reference 25 Results of BWR Trial Plant Review 1
l Section 8 Senior Seismic Review and Advisory Panel (SSRAP) and Nuclear Regulatory Commission (NRC) Reviews i
. MPR AssoctATES. INC.
Section 8 SENIOR SEISMIC REVIEW AND ADVISORY PANEL (SSRAP) AND NUCLEAR REGULATORY COMMISSION (NRC) REVIEWS Representatives of SSRAP and the NRC attended the NMP-1 walkdown on February 1st through 3rd (Days 8 through 10). On February 1st, following radiation protection training and dosimetry issuance, the SSRAP and NRC representatives were briefed on the organization and conduct of the NMP-1 walkdown. The indoctrination and pre-walkdown materials covered by SQUG for the walkdown participants were also reviewed with SSRAP and the NRC. The indoctrination / training materials are given in Appendix C and include information on the organization and schedule of the walkdown, the rules of conduct in the plant, plant-
. specific data on the seismic demand levels for the walkdown, and sunnary infomation on GIP requirements for review of seismic dsmand versus capacity, equipment caveats, anchorage evaluation and evaluation of interactions.
The NMP-1 seismic demand information used for this walkdown was discussed in some detail. SQUG representatives explained that the, seismic ground motion used as a basis for the walkdown is a plant-I specific, uniform hazard, ground-motion spectra developed by A. Cornell and R. McGuire and is anchored at 0.13 G. This ground-motion spectra j envelopes the NMP-1 FSAR licensing basis SSE spectra which is anchored at 0.11'G. The.NMP-1 uniform hazard ground-motion spectra is shown in Appendix C. Also in this Appendix are amplified floor response spectra j developed for NMP-1 using modern reactor and turbine building models and the 0.13 G uniform hazard ground-motion spectra. Mr. Djordjevic (Stevenson & Associates) reviewed the bases for the amplified floor response spectra and indicated that they are being used as mean-centered, realistic spectra. Dr. Kennedy (SSRAP) expressed the view that he believes the floor response spectra are conservative and i s' .
generally in accordance with current Standard Review Plan criteria. As 8-1
y .
a res, ult, SSRAP considers that it _is not 'necessary to utilf re the
' additional factors of safety recommended by'SSRAP for use with mean-centered spectra (1.5 for use of GERS and 1.25 for anchorage evaluation)
-in using the MP-1 floor response spectra during this walkdown.
A second area discussed regarding the seismic demand was the effective grade' level at MP-1. At this site, the turbine building is founded on rock at elevation 243 feet above sea level._ The reactor building is founded on rock at 198 feet. Grade elevation is 261 feet. In the construction of the buildings, the sites were excavated to the foundation level, the buildings constructed, and the annular space between the building and the rock excavation was backfilled with crushed stone up to the 261 foot grade elevation. An elevation view of the i plant ~is included in Appendix C. SQUG and MPC representatives -
explained that while they believe lateral support is provided by the crushed stone backfill, it has been conservatively assumed for the
~
I- purpose of this walkdown' that the effective grade elevation is at about 240-243 feet. This elevation corresponds to the foundation of the-turbine building and the elevation in the reactor building where the structure changes from an essentially monolithic concrete block structure (including the reactor' base mat) to that of reinforced concrete walls and floors. Essentially no amplification is expected in i
the reactor building up to about 243 feet. On this basis, the f elevations which are considered to be within 40 feet of effective grade, are those elevations in the reactor and turbine buildings up to and
<" including the 281 foot elevation. SSRAP was in general agreement with this approach.
Prior 'to walkdown of the plant by SSRAP and NRC reviewers, the three
.SRTs described their progress to date, highlighting areas they particularly wanted the reviewers to evaluate. SSRAP and NRC representatives spent most of February 2nd perfoming independent walkdowns of MP-1. Essentially all safe shutdown equipment was seen by them with the exception of the emergency condensers and related 8-2
I equipment, several= reactor coolant system instruments, several reactor ,
" coolant system isolation valves, core spray and containment spray pumps '
in the basement corner rooms and the equipment in the drywell, all of which were inaccessible due to the need for radiation work permits (RWPs). Following this walkdown, Dr. Kennedy provided a sumary of SSRAP's observations and conclusions:
)
1.- The SSRAP walkdown was performed to determine how the seismic review' teams (SRTs) were operating, to assess how the SRTs were evaluating and dispositioning the safe shutdown equipment, and to obtain a general . sense of the seismic ruggedness of NMP-1.
- 2. SSRAP did not observe many seismic concerns and no serious seismic issues. The expected outliers identified by the SRTs were .
considered by SSRAP to.be typical. Dr.. Kennedy remarked that, in fact, there'were fewer outliers' than would be expected for a plant of this; vintage. He believes that this is a result of the numerous seismic upgrades performed by NMPC over the years which were -
. apparent to SSRAP during their walkdown.
- 3. It is SSRAP's judgment, based on their walkdown, that the SRT members received adequate training to perform.the walkdown and that they were doing an adequate.and qualified job of evaluating the
. seismic adequacy of the safe shutdown equipment. SSRAP generally expressed the opinion that when the SRTs reached different
., conclusions than SSRAP, the SRTs' conclusions were more conservative (i.e., the SRTs may have identified more outliers than would SSRAP). ' SSRAP is uncertain if the utility SRTs used during the trial plant walkdown are representative of the SRTs other utilities might use for their walkdowns, since SSRAP believes that the utility SRT members at ,the trial plant walkdown have considerable seismic experience. As a result, SSRAP continues to
. believe that it is essential that the SRT members have adequate qualifications and experience in seismic engineering.
8-3 .
- , = .
.q Following Dr. Kennedy's sumary report, NRC representatives presented their observations and conclusions. Dr. T. Y. Chang, USI A-46 Program Manager, reported the fellowing: .
- 1. The NRC generally agrees with the SSRAP review findings. The NRC believes that the walkdown has shown that the use of utility engineers is a viable approach provided the SRT members have the proper level of experience. The 1RC still strongly believes that the qualifications of the SRT members are very important, irrespective of whether the members are utility employees or contractors. Further, the NRC believes that the training program is not enough to make an engineer a seismic expert. The SRT members should have the requisite seismic experience prio' r to their selection for training and the walkdowns. -
- 2. The conduct of the NMP-1 walkdown was very smooth. The NRC consented that it is clear that the lessons learned from the Trial Plant I walkdown were factored into this walkdown in that there was a considerable amount of pre-walkdown planning which contributed to the smoothness of the walkdown.
t
- 3. The NRC was impressed with the layout of NMP-1. The plant is open and has considerable space which contributes to both good maintenance and a lack of seismic interaction hazards.
- 4. The NRC observed during their walkdown (as did the SRTs and SSRAP) that the quality of the anchor welds in some electrical cabinets was marginal.
- 5. The NRC noted that the relay review for NMP-1 was performed for a sample of typical safe shutdown circuits and did not cover every safe shutdown circuit and relay in the plant. They noted that the
, remaining circuits and relays need to be reviewed before the seismic review for NMP-1 is complete.
8-4 I
J
b There was some discussion of the uniform hazard ground-motion 6.
spectra used for this walkdown. Since this spectra bounds the licensing basis ground-motion SSE spectra for NMP-1, the NRC concluded that this ground-motion spectra is acceptable and meets the requirements of USI A-46. The NRC also noted that they concur that the amplified floor spectra used for this walkdown are conservative spectra.
l 9
7 4
I E 1
i!
8-5 l 1
ATTACHMENT C Excerpt from Class Notes for SQUG Walkdown Screening and Seismic Evaluation Training Course Section III Seismic Capacity vs. Demand i
i I
. 1
~
Capacity vs. Demand Outline
- SQUG Evaluation Considerations
- Equipment Seismic Capacity
- Equipment Seismic Demand
- Capacity vs. Demand
- Outliers 3.n Slide 25 Equipment Capacity vs. Demand Screening Process
'% iw%, r ei ne. so.ctrum > ms
_ i
[' I O is" b ew > ons
' . ._ . . '"~' , oens > ms
% ,3 ouahncaton Documentabon >
se a , ins Cansetty >
. o*maad Slide 26 Example 1 Horizontal Pump us.e ,,
N Aoor Eievahon - 642' .-
Grace Eievanon . 62cr
- f. > 20 M2 a.37 .
Slide 27 Section lli .4 Seismic Capacity vs. Demand 15 t- -
L ENCLOSURE 2 Pa=leian Paner on the Use of Methe.d A at NMP1 Purpose The purpose of this position paper is to provide supponing information for application of Method A at Nine Mile Point Unit 1 (NMP1) as requested by the NRC. This enclosure describes many of
- the conservatisms that exist in computed in-structure response spectra (ISRS) and the safety
' significance of the difference between computed and actual building response.
Conservatism in Calculm**d in-Structure D*= :rne Spectra The process of calculating ISRS is a complex, analytical exercise requiring a significant number of approximations, modeling assumptions and engineeringjudgments. As a result, the historical development of these ' conservative ISRS has served two purposes:
- It has reduced the technical debate as to the correct modeling of the many parameters which are intrinsic to the ISRS calculational methodology, and;
- It has reduced the costs associated with a very detailed state-of-the-art analysis (which would attempt to remove unnecessary conservatisms)
As a part of the A-46 program resolution methodology, the SSRAP developed and SQUG subsequently endorsed an alternate ISRS estimation technique (referred to as Method A within the GIP) which was much more median centered and realistic than the typical design practice.
NMPC's position is that the application of Method A at NMP1 was appropriate and technically justified. The fact that design ISRS may show amplifications greater than 1.5 is not surprising, nor does it negate the validity of Method'A. In fact, as noted in the SSRAP repon, it was l expected. As described below, three areas are presented to support the application of Method A at U.S. nuclear plants in general, and at NMP1 in specific:
=- Measurements ofISRS in Actual Earthquakes
- Calculations of Overall Conservatisms in Typical ISRS
- Description of the Conservatisms in ISRS in general and NMP1 ISRS in particular Measurements ofISRS in Actual Earthquakes SSRAP developed the Method A response estimation technique based on their research of both actual earthquake measurements and on recent " median centered" analysis. They reference q (SSRAP report page 102) the measured floor response spectra at elevations less than 40 feet above the grade for moderately stiff structures at the Pleasant Valley Pump Station, the Humbolt Bay Nuclear Power Plant, and the Fukushima Nuclear Power Plant where amplifications over the ground response spectra do not exceed 1.5 for frequencies above about 6 Hz. Other, more recent earthquake data from the Manzanillo Power Plant and Sicartsa Steel Mill in Mexico, as well as !
several facilities in California and Japan, has been recently reviewed by SQUG. This data also I
8 4 shows that stiff buildings (similar to typical nuclear structures) amplify very little at elevations less I
than 40 feet above grade and frequencies over 8 Hz. SQUG knows of no new measured data that challenges Gi?. Method A~
l Calculations of Overall Conservatism in Typical ISRS l
- Calculated ISRS have not been portrayed as representing the realistic expected response during an actual earthquake. As previously stated, ISRS typically contain many conservatisms which make them unrealistically high. The primary reason for the development of Method A was to establish a.
i more median centered method of defining the structural response without having to embark on costly new analyses of site buildings. (It should be noted that even the most modern, state-of-the-art ISRS contain significant conservatisms; even those classified as " median-centered" are often very conservative.) A NRC contractor (LLNL) concluded in a study for the NRC (NUREG/CR-1489) that typical calculated ISRS contain factors of conservatism of 1.5 to 8. Recent surveys by SQUG show similar levels of conservatism in calculated ISRS.
It was the contention of SSRAP that the ISRS for nuclear structures (considering the 40' and 8 ,
Hz conditions) would be within about 1.5 times the ground response spectrum (GRS)if the plant were subjected to an actual earthquake. In deriving the Method A criteria, they recognized that due to the variety of ground motions, soil characteristics and structure characteristics, there could I be some possibility ofexceedances to the 1.5 amplification, but still stronglyjustified Method A's applicability:
"It is SSRAP's firm opinion that the issue of potential amplifications greater than 15 above about 8 Hz for high frequency input is of no consequence for the classes of equipment considered in this document except possibly for relay chatter2 ,-
[SSRAP Report, Page 106]
The basis SSRAP gave for drawing this conclusion was that high frequency ground motions do not have much damage potential due to low spectral displacement, low energy content, and short duration. They further noted that the equipment covered does not appear to have a significant sensitivity to high frequencies (except possibly for relay chatter, which is addressed separately in the GIP).
Description of Conservatisms in ISRS in General and NMP1 ISRS in Particular The most significant sources of conservatism involved in the development of the ISRS for NMP1 include the following:
- _ Location ofInput Motion (variation from the free field input location)
- Ground Response Spectmm Shape
- Soil-Structure Interaction (Soil Damping, Wave Scattering Effects) 2 Because of the SSRAP concern related to possible relay chatter at frequencies above 8 Hz, the SQUG methodology specifically addresses relays which are sensitive to high frequency vibration.
Such relays are included on the Low Ruggedness Relays list in Appendix E of EPRI Report NP-7148,
'2 I L.:
- Ground Motion Incoherence e Frequency (Structure Modeling) '
- Structural Damping 4
.. ' Time. History Simulation
-* Non-Linear Behavior (e.g., soil propeny profile variation, concrete cracking)
- e. Peak Broadening and Enveloping
- Clipping ofNarrow Peaks
. The degree of conservatism involved in each of these parameters is specific to the building being analyzed, to the floor level being considered, and often, to the equipment location within the specified floor level. - These conservatisms typically cannot be accurately quantified using simplistic calculational techniques since each parameter contributes to an overall set of highly non-linear responses. Thus, it would take a considerable effon to quantify the exact excess conservatisms inherent in the calculated ISRS at NMPl. However, on the qualitative level presented below, it is easy to see the origins and levels of this conservatism. For the purpose of NMP1, the only floor level where Method A was utilized and for which the ISRS exceeded the reference spectrum was drywell elevation 259'. The components in question are ERV valves and motor-operated valves which are mounted on piping which is supported off the top of the 259' elevation floor beams. Thus, the following discussion will be geared to the NMP1 reactor internal structure. The following parameters are the source of the major portions of the excess conservatism:
Loatinn ofinnut Motion - The defined location of the plant SSE is typically part of the design basis documentation.' The SSE should typically be defined at the ground surface in the free field as defined in the current Standard Review Plan criteria. The defined location of the NMP1 SSE is considered the ground surface in the free field. But for purposes of generating ISRS, some plants conservatively defined the input (currently identified as the
" control point" location) at another location, such as the embedded depth of a building basemat. This conservatism can be significant depending on the specific plant /builditt configuration. The NMP1 reactor building is founded on rock at elevations which v:9 between 198 feet and 207 feet. Plant grade elevation is 261 feet. in the construction of the reactor building the site was excavated to the foundation level, the buildings constmeted, and the annular space between the building and the rock excavation was backfilled with crushed stone up to the 261 foot grade elevation. NMPC and SQUG representatives believe that while full lateral support is provided by the crushed stone backfill, it has been conservatively assumed for the purpose of the A-46 program that the effective grade elevation for the reactor building is at 243 feet. This elevation corresponds to the foundation of the turbine building and the elevation in the reactor building where the
'stmeture changes from an essentially monolithic reinforced concrete structure (including the reactor basemat) to that of reinforced concrete walls and floors. Essentially no amplification is expected in the reactor building up to about 243 feet. On this basis, the L elevations which are considered to be within 40 feet of effective grade, are those elevations in the reactor and turbine buildings up to and including the 283 foot elevation. It should be noted that SSRAP was in agreement with this approach during the trial plant review conducted at NMP1 and that the NRC participated in that review and concurred with it.
For the 10 valves evaluated using Method A, the effective grade elevation should be taken at elevation 225 feet. The basis for this lower effective grade is that the response of these valves is primarily driven by the response of the top of the reactor pedestal (Elevation 259' 3
l m
where the pipe supposts are anchored), and not the reactor building itself. The reactor pedestal is a cantilever-type structure supponed by the monolythic concrete foundation at 225 feet. Therefore, reactor pedestal response is driven from elevation 225 feet by the
' monolythic concrete foundation which will be responding with input SSE ground motion.
Thus, for equipment supported off the reactor pedestal, Method A would apply up to 265 feet. NMPC and SQUG representatives concur that Method A would be applicable for the subject valves at the 259 foot elevation of the reactor pedestal. The amount of conservatism inherent in this control point placement is discussed in the Soil Structure Interaction (SSI) description below.
Ground Ranonse Spectrum Shane - The SSE defined within the plant-licensing basis is the appropriate review level for the A-46 program. Some utilities utilized alternative (conservative) spectral shapes for the earthquake levels utilized for their A-46 resolution (i.e., submitted as past of their 120-day response letters). The amount of conservatism is directly related to the difference between these two spectral shapes at the frequencies of interest for the structures being reviewed. This factor can range from 1.0 to around 2.0 depending on the differences between the spectra.
The licensing basis safe shutdown earthquake for NMPI is characterized by a site-specific horizontal ground response spatn::n anchored to a PGA of 0.1 Ig. However, ISRS were not generated in the original seismic design of NMPI and this earthquake was not used for the USI A-46 program. A more conservative earthquake anchored to a PGA of 0.13g and with a NUREG/CR-0098 shape (broader band) was used for the generation oflSRS in the A-46 program. The use of this alternate earthquake input definitely contributes to conservatism in the ISRS being assessed in this document.
Soil Structure Interaction (SSI)- Typical design analyses do not account properly for the phenomena of SSI, including the deamplification with depth that really occurs for embedded structures and for the radiation damping effects inherent at soil sites. Fixed-base analyses have been performed in typical design analyses, both for structures founded on iock and for structures founded on soil columns. For rock foundations, the fixed-base model has been shown to be slightly conservative depending on the rock / structure characteristics. For soil founded structures this assumption can vary between conservative and very consenative, depending on the level of sophistication of the modeling of the soil-structure system. The simplified analyses that used the frequency-independent soil springs were typically very conservative in that radiation and/or material damping were either consenatively eliminated or artificially limited during the analysis. Soil properties were also typically not adjusted to reflect anticipated soil strain levels. Significant reductions have been demonstrated over design type analyses using more modern techniques. These reduction factors are highly dependent on the specific soil conditions and structure configurations, but values of around 2 to 4 have been seen in past studies.
The NMP1 reactor building is founded on rock, thus the amount of SSI conservatism inherent in the foundation input will be small (but not insignificant). There is additional margin in the conservative assumption ofignoring the restraining effects of the 63 vertical feet of embedment against the crushed stone backfill. The realistic inclusion of the effects of this crushed stone would provide a significant deamplification to the reactor building ISRS, and some minor deamplification of the reactor pedestal response since some connectivity exists between the reactor building and the RPV/ shield wall / pedestal structure.
4
Ground Motion incoherente - As has been documented in the EPRI seismic margin report (EPRI NP 6041), there can be a deamplification effect on nuclear type structures due to the incoherence of ground motion over the relatively large dimensions of typical nuclear
'stmetures. Conservative reduction factors as a function of frequency and building footprint have been documented within NP 6041 to account for the statistical incoherence of the input wave motion. These conservative values range from a factor of 1.1 to around 1.5.
More recent studies have documented even greater reduction factors. This ground motion incoherence is applicable to rock sites like NMP1 and is particularly appropriate in the high frequency range where exceedances are noted for the NMPI reactor building.
Time History Simulation - ISRS at NMP1 have been generated using a time history which is intended to approximate the desired earthquake spectrum (0.13g, Regulatory Guide 0098 shape). This process involves the generation of an artificial time history whose response spectra envelops the SSE. The amount of consenatism involved in the enveloping process has not been specifically calculated for NMP1, but can range up to a factor of 2 or more unless significant resources are applied to minimize the degree of enveloping.
Cliocing of Narrow Peaks - The SSRAP report and the Generic Implementation Procedure (GIP) recommend procedures for adjusting narrow peaks to reflect two areas of conservatism:
Narrow peaks are not as highly amplified in real structures as are predicted by linear elastic mathematical models, and
=
Narrow peaks in ISRS are not as damaging to equipment as are broad frequency input such as the Reference Spectrum.
The GIP procedure recommends an averaging technique over a frequency range of 10% of the peak frequency (e.g., I Hz range for a 10 Hz peak frequency) using the unbroadened ISRS. The NMP ISRS have narrow peaks and did not utilize the peak reduction methods from the GIP. The consenatism involved has been shown to be in the range of 1.1 to 1.4 for typical narrow peaks at several plants. We expect the consenatism for the peaks of the NMP1 ISRS to fall within this range of 1.1 to 1.4.
There are several additional sources of conservatism (e g., structural damping, structural modeling, structural / soil non-linearities, peak broadening and enveloping, etc.) which add to the overall conservatism in the calculation oflSRS. These additional conservatisms, coupled with j those described above, reinforce the overall levels of conservatism in ISRS of between 1.5 and 8 which were referenced by SSRAP (LLNL Report NUREG/CR 1489), and explain why the consewative NMP1 ISRS produce exceedance beyond the 1.5 factor. '
The Difference Between the Calculated ISRS and Actual Building Response - Not a Significant Safety Issue The expected differences between calculated ISRS and actual building response do not represent ,
a significant safety question. The lessons learned from review of hundreds ofitems of equipment '
i at various sites that have experienced earthquakes which were significantly larger than those for Eastern U.S. nuclear plants, are that missing anchorage, seismic interaction hazards, and certain equipment-specific weaknesses (incorporated into the GIP caveats) were the seismic !
I 5 l l
vulnerabilities which cause equipment damage. These areas are conservitively addressed in the GIP. The NRC staff acknowledged the seismic ruggedness of nuclear power plant equipment in the backfit analysis for USI A-46 in which they stated the following:
" . . subject to certain exceptions and caveats, the staff has concluded that equipment installed in nuclear power plants is inherently rugged and not susceptible to seismic damage."
[NUREG-1211, page 16]
Method A is only applicable to stiff equipment with fundamental frequencies over about 8 Hz. As noted earlier in this Enclosure, SSRAP and SQUG have agreed that excitations over 8 Hz have little damage potential due to low spectral displacements, low energy content and short duration.
Thisjudgment is supported by industry and NRC guidance for determining whether an operating
. basis earthquake (OBE) is exceeded following a seismic event at a nuclear power plant. EPRI Report NP-5930 and NRC Regulatory Guide 1.166 recognize that damage potential is
'significantly reduced for earthquake ground motions above 10 Hz. Therefore, the value of building amplification at response frequencies greater than 8 Hz has very little safety significance '
Reactor Building is a Tvnical Nuclear Structure The NMP1 reactor building and internal structure are typical of Mark 1 reactor designs and consist of a cast-in-place reinforced concrete substructure and reinforced concrete / structural steel superstructure. The concrete substructure, which is founded on firm Oswego sandstone, begins i 68 feet below grade and extends upward 147 feet to the operating floor at Elevation 340' - 0".
The reinforced concrete walls vary in thickness from 1 foot 4 % inches to 4 feet 0 inches. The reinforced concrete surrounding the drywell extends from Elevation 212' - 0" to Elevation 340' -
0" and varies in thickness from 4' - 9 %" to 7' - 0". The reinforced concrete surrounding the drywell is integrally connected to the reactor building slabs at Elevations 237' - 0",
261' - 0", 281' - 0", 318' - 0", and 340' - 0". The reactor pedestal is a 5' - 0" thick cylindrical reinforced concrete structure which is tied into the massive reinforced concrete foundation surrounding the drywell. Therefore, this reactor building and internal structure represent " typical nuclear plant structures" as defined in the SSRAP report and the GIP.
Attached to this enclosure is a comparison of the seismic margins between Median Centered Analysis and Design Basis Analysis for typical nuclear power plant structures at other facilities similar in construction, building frequency and damping to those at NMPl. This comparison has been developed and compiled by EQE International, Inc. and is meant to show that factors of safety in original design basis analysis can range between 2.3 to 5.4.
Conclusions The NMP1 reactor building internal structure is the only building where Method A was utilized and where there is an exceedance to the reference spectrum. The NMP1 reactor building internal structure is a " typical nuclear structure". ,
The results from actual measured ISRS on " nuclear type" structures support the 1.5 response levels advocated within Method A. .
'6
Qualitative assessments 'of the conservatism inherent within the methods utilized to calculate ISRS
' have been provided above. These conservatisms are typically quite significant (as has been independently verified by median / modern assessments such as the LLNL study) and can/will result in ISRS ivhich show amplifications well beyond the 1.5 factor from Method A. NMPC feels that the specific exceedances noted by the NRC (beyond the 1.5 factor) on NMP1 are due to these high conservatisms inherent in the ISRS methods and do not invalidate the application of Method A.
There is little safety significance in the expected differences between calculated ISRS and actual building response. The largest safety improvements are provided by appropriately reviewing equipment anchorage, seismic interaction hazards, and certain equipment-specific weaknesses where seismic vulnerabilities have caused equipment damage in real earthquakes. Reviews of these areas were a primary focus of the SQUG GIP process. Therefore, NMPC's implementation of the GIP at NMPI resulted in significant seismic safety enhancements.
f I
l I
7 l
l
T l
l ATTACHMENT TO ENCLOSURE 2 l
i I
,1 9 .
kr a
e c e m r 0 i n n t
c 6 de
) ic) i r
g) u) e ig e
p ge 1 e p 4 e4 p s8 N0 s S 1 d S er S er l o er d er 1
d e
e u l gg u de m
- 2. sa 0C i t iS g teu g 5i Egu
- ht e
e g iF iS iF 7. F di w e 2 ( 2( ( oF n
. ~
G e
R 1
0 1
0 0
M(g i
m 1 i s
t 0 a v
r e
s e n
_ o nh c .
i gd ri 3
5 3 3 3 4 t s e
nt n ag 2 5 3 2' 5 r a Mise e lp h
D nre isd se lo k
l r a da f o
_ e ) ) ) ) )
hd
_ mP ge I
g 3
e g 6 ge 7 9 d te ud 7 re 'g re
_ i de 3 u r 1 r u 6 ug 7 ur 2 u nc e e r e I ig 1 g 0i 4 ig 0 ig a, xp Mem F
(
iF
(
F
( F
(
F
(
y e E C
e lmse n S c ig S e r r n a ig sk lym s e
e ia s e ) ) ) ) ) ve it h D BaP g 7e 1 2 5 9
- D t
s ge g e ge ge laf 7
ni gnt 8 3 g ur 8 r
u g 2 ur 0 u r
4 u r
e o r
t n
5 2 ig 1 ig 1 g d a ise s iF iF iF e n n
o e
( (
F
( F
( (
l P
Dm A ds er ht e
a w f wk o e e d a
"g k ht e a
n s u n qo w ip
- 6
?
6 6
. n
_ s 2 5 5' 5 5 ht e i,
_ n rb a )
a e D
ird e o iv t
t ge a s g v r
Hu od e s
s j n e
te l l e e gs o n
e i
i o
i o i t
t 5i (c S s S 7. )
0 ak n e S e i S e u kc ivc t iS
/t ki cS kc l i
e p
m o a o o o o o S he p h C R R R R t n s
_ r oi a 0 fd 6 iss em 1 e
n ly/ k d i
rl e t
. . . . . a a u oe f t
F R R R ne a p ou l v 0 5 7 0 5 e r n G.
F e3 0 6 1 4 5 g g 9 3 3 1 1 ei e E .
ht s e R S t d a R a( r ht o S
I 3 f d
d2 d d ye e r
tef oo e t
te z Iz te nn a r
nem e n t
I I
3 t I zt z i z Iz n eig e n
my 8- I l I e b r e 1
4 2 0 c i
ss er 7 0 1 1 0
1 n d a g u m l
e EF 1 ia oe r e
d hh e s t w m I t ,
S s
d u R
_ n t t .h S
_ a e I l
e e e e S k c keT n dl c a ea t e
t e
t e
t e R S
o ol i
n cW r
r c
r c
r c
r c I d d - d e
t e fo ra n o
l l
a nll oa nll oa n
o4 C C P m t
. is a
s R RM e n d r de ra de ra dear i
s a b N NN s ht e
s R, S e e c a c e c e c B n e e a t n yt r e r h e
rh rh r e ig ht ht a o o r fo S fS o fSo fS oh n s n nc h ht
_ C t S no c n n n m ig s
e o ous t c
ie ie ie e e d s s a 5C R R R R D to i ni ts f s h o nn e
_ ht
't n
t o
i ioalp t
a b a..
a nr t
c s r e
&e l
g e g e P ie m rd r r s f ol u mll mtu n o m f r i lp n g y g d t c d e e c yg ht p n o r
l ur l h a i. i,a n a in mu i t ra m i
u uS r k nh d fo i
i B tr e l d Br o mS i d a t
d l S l u e ot e se ixi r ri a ixi l la ys l uu r r P a o o to er tno uu E v ni s c
_ D AB t c
a ir e
c a tx oi r AB B g h e a y Cl a s
e t eE Cten O n c s a
n n R I R I x ip a lona w b
_ 2 s
m a
m o isa e e u
d a d t
Cs Dn s p o la V
e n s t i n e iA i Cre n
_ n 8 fe m t s ia B B D ip a C t
n ni d l
P
'A d u a a s a e E q l l
Pb M S E P S
- 1 2 3
d
[,
Tv k,
t
. e
- e. y .w n b s _
o ,
d s
dn o
u i -
- r s a y g e - . _
i u _
- U p b
- o i -
Eo m d ,
o D a '
,~_. SR.
.s _
C 3 I p s' -
1 EI.
SD i a P c
- a r
5 2 D e
3 _,'
C t = 5 I T.o E -
c g 3 Z gg E
.N e
5 3, . o( F s 1 \ . s p I g
3
~
S ie' Y
C 0.ao_
S
,i i . _
8, N 0
- 0 .
3 - . C A 9u U
S = ,eI . -
i)i - .
- s. EG e -
E i n ,
R R=r T .n g CY
'/ .
r S
i r
a / r EE.
- t'Lo
- P M e- . 5E i.
C ~
E S m
- 4 8
8 6 19 s
~
- g. a.
f lY OR f'R s
- 1 4 1
- ,,_ 5I r EL e
r 0y 5r
- a
, RI e X c
&r u - - EU.
u 5 b -
, . . 9R e 0
=r g 4e -
i C.z i
F 4 F 0d
- 6e t
~
D.
L
- e - - - - B r.
- tD e
s.
o kr e s 0 0 0
8 9
0 9
8 8 o
- e. 0 ct ot
- s 5 4 2 1 DeL ~3 x3 duE mC o
rR FN
- e O
m hm ......4 6 .d a. . . . . . ..i ..;.4 4 .1 kli l .. . : 4. . .... 4. 0 3 84 . 3. W 4 U li.3 4 &4 4 G1.4 3.' 3 43.
- % f 5 +? e^8 # 9 4 e 914 f. 4. # it 4f 3 '4 t tr8.9 t-f f H f f *** t I f 84 f t: f*n D ' 8 f ? * * - 89
- it'+'9f t 'id f f f f ] '
O .P t ' t . Y >$ f I f f f i. tit'?-; f f1 fit!1! *4 tt
- t'? lf f 11 it '-f1177 1
-n s t : ten t : n e t r. 3 +r ew -+ e tt stet re* it :t e -r D
t TM1 F n-e n
- ?.f f ;-tf t t ti t l ttitt
- n.t s .I s..
f : fel a0 r: 64s feai.n-' . itti
- sun;ttif f.aas?ttasunseed f f t f+t ? 1t+M a P*i
-ee.c c ^s a s l diii una4.u ;waw:4 i.HH:hdi': tiiii.+::i":f'.:
JN ""-!Hiti' ; *G.
@ 2m. namm t;.
O A :r :- n= :. :: :-:r: *-:. :=.:::: C 8 r:.u.y .n :.: [.
e ~ *
- . L. ::::::
wn...
cw .m:!.1+t
.u. . . . s. ::f.:
.. .. s . ::.r:.y
- m. ..s... =a.
. 4 . :.:!.!E..pl . . . ..u:t. . ~i. l'b.:.:.:e
. . . U:n:s:; .. .,
U) *
- 1".1.".!.. .e t. .t t.t t.t.' l t.t.M. 1. .f t t. . t.f
.- . . . . t..-.
e..r. *.r t.t.t ,t f l O g a' . i fi.te. e:" .
erst e-i etwerf ertnet rettpA} e o,
.c.. 1 .es.4.M.t > . . . . . . . . . . . . . . . . . . . . e c c . c] .. ~t.:y e.r. .
ewan c ; . . . . .
- c. .s w i.c n.r
. ..usannes
- et e. r e vi s+ f +s t s t+tn?+ tet we+a4 44o.swene:
- ; eue r . ;
- =
-2 E .rnt e n.,-t t .nmn,- wrv,mr t mnt e E L E -M:
t t ewn- e n-th g e O o as rtie:
7: rrimi tic?:-tert-::::tmrt: +inwters-steeiterre ?:rr.e tr ?: o c6 o C e e e o t ' -- r . H o o t g an.uat-2.e.ninet :4 een e 4 su+etun nece wen np y t tc.- . e
~~
y g ci i.- pt m y E
o H liiH Hi.
enu4 :euneu+wl tith +H !iF ~ HHiHi4H4.f,*it i. +. e. +. n.4. a. .. . . .
En O
o a o -
o m
- o.
,e e. e. .n . . ,.
2: ,......l.+....h.......
.r w.. e. t. t. ' m .it. i.
tt+ t.o: !4 + t r.. i- t-
+ 1+.1.. ,te. O .n. . t. . s. .
.O c w o tt. .e.4.11w. lte. n. . f +. n. ..l. .: . -.o. . ,.+. n .v . r. .
E -S-
.4.
i:4, 6 ! '- .
. l. n +. i.t.:'t. h.4 : . !.t. .ir, u; lif
- e. 5i4 -
- t. :i:.r"n :. ~. : : .:i. . t. :-
to ew ED o y>
a.a ,
- s. .s ., s.', u, m. u. u. . n. . .n. 4,1 s s.a. !
. . :.r. ..r
., su. .-ru. . e. u. u. a..+.n.w. . . le.
s
+
m L.!
-C
- .. l. 1: .i!L;ii u., ; af1!i 14 mi- : 1
] o g
- f. i su. :: n n. ".
o-it; .
e q}..i...
g:pr :p:
i i : i w
r+ -: :lo y~
,o, -I r r r fir c -
m g s. u-rp* r .
em .
r e. rt- .er:. ente. . :: ..y co W 7:
11: g *;.j i, 7. 3l' . 't. t. !. ' f. i :...to:lf: g.
il ,4. : t y .n n tj . .. * : r. ' .g:. t, .
2.
- i. .
- Q") C- -
t a O me
. 4
+
.. u t u s sa.3 m., .+, n,,,n,,n - n,t w m.,4 sessim e tt e,.su.e.u.g...m.
., s ,o,,.. --
g , ._,,,, , ..A..s e v4 gu.,,,v.,
.,. ,,u,, ,
we.u.u ,tu, ,.u.,
p, a.,n.a.u.a.L..
- . . . , ,'t=-,. a d.m,,a.4.,
, . . . . .,n-. Lm.q -s,a,,..a.,
. , , m,,,.,,.,, , e.44,
.,, o
- C bN .t e gg g gg,,, f f tte-! f1 e '
's t4
,!.3 44Me 6t #4ems Me+#H t. 346+s MeHMlHt4ptets#f M 44444 M4+e n,444.s t.H.nHe ltte+e -644 . ..su t 7+ . . . - ' etPfte+'N t Q 44e .44 e 6, *. #M.a sue 4 6.s e +e.'i
- * .I *..* * ' .: f. ;.4. :.1. ::. . M. . *f... .t-7.:: :. 4. ; .* :. .:.: 7 :.1
..! . ., t: : . :.. .. . . . . . . - * .
- f/ 14. . ,
M .!!'1!r::.
1
.. : r.M.a. r- '.1 . . . . . .
O 48 84u s M. ..4 4 4 4.kaa.3 H3 t.14414 >M 4 8841 && H M3 4 6 44 4 4...iul44 a44 4.: 4.,
i . . . . .u.s t s a4 H.,
c:..n.:. r. .:
e co ~m ..:r::.:. n. ..:n..r..:1.:.:.::..:::: . :: : ::
. . . . . . . :T . . s .n.:::::.: . .. . . r:n. .nt ..
- ... 4
~
3t.M.....!.!.1.17. 13.1%.,t.J. ..!.1.1t..it.1 i.3.I.d..11 ' ..r..n...
.e.rr.::u.
. G. lt..[f.tl. .1. r...i. . .t( .r.a. h.. .t.r..
.t!..!.!.!Es..t..i.
,t'D (D L1J 8.tf t!!!!!!!!!!!!!.!M fliitC!Mi .l?!.?!!'!LI!!!!.?!!!1?l.il .f..!.!.1.1M...J..i..A!.0lt..r.. U.,k.1.*&. t 12..;.
'"" it!.t!!!!.!?i!!!11!?i!c, it!?!.*
b @
.C f t. .*.(4..t.t. s..f.t .H. ..e.t.-t
. .ti. .l.t.'s.11. .'a t. .t.M.. 99. 9 9. .'.M. 9.t. s .t.*. .t p
.i. .t.t. .e.t+t t. ., f tet t *4 tt M .1.1.f ".
e A 4- t. .i.t..t.14..s.t. .s.ti..t t..i4 10 4 64 44 410 6 64M 84 44 8 He=s 4 44 M
- 4 6 M 48 Ni . ... . . .
O O ga
- E O
4-P 4 5t4H tM j.itt*
4J4filt*f 4e6 H
!:Tf- F:T!11:ttt!!1t e
f Fttt t ,#
- !* ?Mi* ???!*?!;;;?tMtTtif f*tt tf t itti t f t-Fti f M?tt f4 0+tt1td.itt t f
- 1 tif f f1t't ttiTlti 't tif f ?!*T1-f ? F1 f tf ** 'M ;T Ti tT:Tf r*ST
-f tt e f!1 f t111 t t t's tt+
f 1;:T; *-;t*t F r; f t **
- ? t t !11;"~ ; ; ?n r
.1 6M tttt!
'* tT * !
Vf tT:
8v e QJ O)* Tf ?tttfit tt-fl t t Htt rs tf 4tt1t+ tit-f t e '4??f t it4tttM't ri ty M;at tt t to ge t tf r. *- t tar t.
ee 8 ;4 HH4 H l+oMtuMOct g46+ 64 404 '
4 bht-iMM i t6o d-D pet-61004HeteHH # ytN t m Ili ggN M N $. $.hi!h nu.
. . o. n.u u.* .fs.kh'-ih*h .wu.
f+f. t.199 t. t. t.+ t.4. M. i.f. t. .f i. t.' t.4.t.t. f M 1.. .n.
ht!N
- n. .. u. n. . hh!-T Nh
. . s.f"u.
F.
'$ h! N' i e..s a.
.f.
i.t4
>. .s.
u.. .s..a!
'i.u.
Pt1
't.'t
- h i- d '
h!a.N
- t. 1 L, . *u;!!
t- f.
. . e. h.'
- f. i. t. F
- n. . *n.*. *e.$u.u.
- r. t. i.t.
N $ N.m. kNiN..
t.41 t.+
. s. n.s.. .
t.t. ?, ' t. d.'
I',+E ',,
- o. : ..s
,t.
' t.
etton ste&>H +r- e u + ,t+ n.iw. a. t.'t t. $.
4md .gn.euw..el&ii-k Le *n!!e tos 1 reou c,r 1:1 au f; nt..
C @ lll II:i d:
- rnt, r f l .1 : 3: :::: 1 iti t t i;t!- .:8:th if ! ! -'!!
'.ur ::t:ntr' +
- : ~
f'!! :
mOa -.i..,,, -itn -- .
r:ts tat r .! : .. :t : # '. t.!!:l .
O M *E*
.i f
4.84.14...4-
.- 4. .k I.44. b>44.14 ..- . . .. . . I b.
i-I 8 4144 . 4. -. l..I.
- I2:.. .i. .A.. .4.& .44 4.... 24. M. 6 &. .l 4. . 4. .t. .b . . t. .i' M. l. . 48:
emme O ,!.! .*; Ig .: .9. ..S.t. . u.. 1.1.!.
.n: n t.!.!n l a.
1..; .i.; . . . , . -..!.,.. !.!. ...I. 1.: .S.t : .;;;;.. ..
.o-..
- ..m .f ...
"e N 82. .:9.......
. . n .":. w. u n u r .."..."........uz....o. . . ' ... .....'
" . .n.
f
. 4 . .. . . .. .......a. .
Q ll gC :l trif tt #:tl Pr:1 stt f f f f t!!1 t P!!P?t . . . 1 t i t13 T!1 . ?tttt1:T!! t .'tr
. .'*.':::s. .tt! n? n. t r: rn u s r u n n l u r a n.n u n::::::ps'ltlit Ewy 'n -
n -+n r r. :p:nr:{:r- -inniannun r g: - o
== gg . . r . . . r , , ,irin :. , - . , , ,
. g e e o m e a e e w w w N ogog e >
e.
e a 4 n m.
n n m - e o o
k u*J. .[. $ G)' ucpere;ox:y U (D
- O G .O DO(ey xgge O
O.
eM1 ee D. C *
- e s
n 9 p
o I.
i ,
o s . ' e i 8 2, u r
e I i
i 3 t c
u R, -
, 'n iI g t r
S
, !l h l a
L s d
l g 'g a
n r
e l 8- I .i ; a D n l
i t
r e
n t
e - '
t aa r n t a si I
i s
ot s n -
n pa jr e ly e '
L '
a t
s, 1Te a n
C l i v
yb 9. m l
A 6n n
a I
i i.
[1 13 3
1 C
y k 4 to Aia Ssl I
n Un i
,r a
_ t a
d -
, T e -
F t
r -
ig n T, f
- _ - d" M g il I 3 '2-t l
i 6 u-B '5 i
- 1, r6 I _u l..
I o3 B -
I t
1 . l c .
a v
' t
= el e E .
t t
i e e RE n v g
f .
nu e
Su s
l a r u j g
ne Ip c
8 P c d
ee pt S 3 3
d * . i d.: on e
- e p
a g
7 l - lo s wp r
u 3 t s
g e
L v2 ta r
IK i g
e m s= e3 F r a
- u g
d i
5 F f _
o k .
a e
P .
r 6 e #
%n I
I m
111
' I I M 0- -
m / Ill I
'E / /// /
s '
/
V // //
c //// .
e
" )
c) m / /1 //lI '
'E m e O / // / // -
i c .g ./ / I
,/
/ .l.l.
.,I 77
. ee l
.. ; ~/ / 1 . ,
- i
//
/ / / /u/
.5 a- 2 E
/ // / N/ /
/
// 1 I
I a
.$. h(Yt 3
. Q) m N
- - ~
( ._ _
g_ , - -
4
' li. : : : : -D u) - u ,.. u u. u... .
O h speettal Aetdemil'as O
Z i
i I
. s .
e
.=
. $. . 4 g.
Q . . . . ,
.C ,
M
- . . . g. .
O.
. o g . . . . .
LLJ .
.. - - g. - . .. . o :-* en a c, er coa o c ;..
m
.- c- e
. , . . . .. g2 ..... ... ... ,.... . . . gcg E -EL ggg ... . . . ..u . .- .
E E E 5 a O <
. . . ., ,. "J g ..s. . . . . , .o. c& a, a 8 o,r -..s.
e, ... . - .
. -e.
. i, g*. ?. *. " M, .f . !" Q. et M ,M ,M ,
M 1*P ' . "T,."
. (f,) . Em . . .--
, .~
u .
- 1. ,
...#. ,,. i. 7. , e n n wm..
s .- .
. i.,
..i.4......
.O $ . . . . .., .. ., ... .<.. O ..o (f) s a ..
g g. _C .; . ._
- y. . .. . . .
t._. . .
m
- O .!
1 .
. , . , . ww ,....
- . . p.$. 9....q.y..
. ....a.9. .;: : 3... .: r,. ; , a. , s.g..r;.. . . .. . 9...;............. .
m t !
. . .. ,i' t,
- 8 : .:
. 1. . l . . .. .,si.
. * ..-8.t.et ~1 . -
..... . . 1 *.:- i..-
.:4.. .... .
9 u
- h. ,
3 r-*4 -r - t - r : - p --- ; . : . : gn eaum m
W N e 4.
.. . .....4...: 4
.s.....,'...........a.&..4...... . ... .... . . . p ' gg: .. &.. . .
O 12
. . . . . , , e. 0 g .s...:..~1.,*...~.*.:..v.t,.t..~.~.=.,..e.s...-.
.....m..e., .# . . .. : . - < ..s.v.t..r, .
%,. ,..,r#....
.,.. t. t.=. .g
- . . ,, ,.. ,. .p., . , s.: ;..y.e .s ..o., ,
i.. : . . . , , , . . . .
, a . ., a .
Q
.4..
, .j .- g y y ..7..7.....,.5..,..._
Oe ..H:. .. % s t ::2&: ..? ::.i&:&r :.H:1..w ::. 4:s:L:t:.+:.'. : . , !.: ;:.n.
my .. 3..: . .:. ; e"g.p.:ev. : .;crm.: :::..r.e..n.:c .: = r. .: : vc . ' --
n"r 0..s....i. .
e .;;. .;. . . : :t.n..;.. .In..t.k..I.r.,..r. .t.em..,..!.,n..t:t. . : .. . :!.$.
, . , . ..,.1....I.:.C.r:t.x..t:t. t..,..:.
m 4.:1.......,.
-=. m CI- ....,.....s...L................
- , 2,. . .
i
.....,.a..
> . .. ,, .,.. . ,. . ....e.,
s.
y @g .,..u...
.. .. ......4..
3a,..<......i.....>......4....,..s.,..,..,e.......-...
. .,....:........~.......,.. . ,.
C .C ,C, ,,, rcv,.r....r,..n,...r+t,,r+...rw,.,.v...~.~,.<..,.,*.,.r..,...,..*,..*..
.i.4,...,.,. ,
..,. '..~...>.......
g g (2. : .
&4.....:...........,...,..,..:......,......,.: ......,..,s,.....,....,.....,. , . , . . , . . , . . . . .
..s.......
EE ~
++i'+'.,~.'.+".'..+'4..'~.4..+'4-'..+.........'..'..i..i..+.'.....+-'..'.....+..'.-'.'.-
ty mm
- 2. . . p ... ..
..+
..s-: . . . . ..
.....>..i....
.s.. . . . .
+.....s......,...t.,....:.... .,
..e . .-
t i . ,.
- t m 1a :: rr. -:-:
g) bo o .! iw .-; i. : '. -
- . . .r g.2.5 J :. i. .3 .... .... . . ,
. I L,O,,,,, F g) .,
. -. . .. .. .. j . .. .. . . . .
g ma "N.
. . . . , . , . . . . ; .q.+. ,.-.; .. g -; . .
~3 - - ,. . ,
~, a. o -
g T- N e n
n n
n . y o
. oo
\
LL.
ll H i
~
8 xm m x (S)
- uonneleocy GG 1 Q.
W W W CO O to 1 1
I 4
1 I
i i
i l
I I
4 .
S R
S I
E II 1
1' 2
h 3
S, )I { j; * '
T _
S 1 .
g
, i!
s( I n
i a p*
3 v
d mg e e
r eyI i y
a p n l
as i
l E
l l
rt e t
e .' Q g t e ci et pa h
S n I A 4 :
S r e
l a
n e [ s 1 tl .
.L d e e r t c e
- e 0. c _
C P t t 5A x t
z t E n
(
? ii y s c is i
a lI I i:8 !}tI
/
n e
p ly a
n d e r A e -
/ - 8 r
6 4
M 3
3 A-I
, S II
- U ,
B 1I t
c i
g n
t t u d n
t=
r l l
a J n SP I
iu B
r o
d P . _ t
. e c "I t o"
p l" a e
- ao M f
s"
, 1 L , t t e? R 6 u
& "pvi; eb?
e r ,
u i
g -
F
1 4
1 Figure 7: Diablo Canyon (Plant C)
Spectral Comparison u, .
....i. ..... .; . . . . . .
y,- - - - - - - _ .
w.... .. . ... .. ... .. ... ..................... i . ... . . ...... ............................ .._
',*. f .laise f freguesecy range
..st .
"h for equipownt and piping 2 g. .............. .5;
_en ..... ............. . . . . . . . . . . . . ...... . . . .. .... ... . . . . . . . . . . . . . . ..
i :
7 i 6~ ~ - - - - " * ~ ~ - " - ~ - - - ~ -- 4 --
~ ~ ~ - - ~ ~ ~ ~ ~ ~ ~ - ~ - ~ - - -
.'n9- -- - .-. -- .-
Seismec qeselification beds 4 ........... ... . ... ..... ..... . ..... .. 4._g.........,
+ . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
/
/ 'g
- 84% site specific g% :
NA'. . \
2--.......**.f"/ -
. . /. . . . .. . . . .. j . . k . . .
N W 5 % -.
D
' " ' ' ' ' ' * ' ' ' I ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '
M' M5 M2 T. _ 1 ; Otr)
Q S p Pe A h . f TS R.I *
{d,d -:.as _ O'N e
sg,7j ~*
Figure 7 31 Coseparison of fkw revoise spectra for owiprnem quahackan far the conuinment bulkkg. kaerlor structure, E3140 feet, cast / west response, anske cangeshun elas Pwlic sasand Eleceic tas,s'W taas Tea assume Pseems
E 1
Figure 8: Diablo Canyon Ground l Motion s- . , , . ...., -
5% Damping I 23 - _
- l l
4 -
I
- ~
7.'s\ T.
3 1977 Homerieusiasdon
- / .
~
(#**'"='k) l 5 g
- 1 f
} / \ "'**" * "* i gi.s-f x -
i */ .
I g
/ '
~ ,
, \-----
/
/ iggs adedian gf . -
g . . . ....*1 , ,...f . . . . , . .
1 2 3 1 2 5 to 20 50 100 Fregg (Hz)
Figure 7$2 Compasaoon of the 1988 sisc-spcent, modsses and 84d> twreentUo herucotal resporee spectra with the 1977 Hosatt evaluacon 00ewmary rutponse spectnun.
sessestaurenroenrises E PasenssowuiscencCampear t T sesvehe, t
I
Figure 9: Plant D Auxiliary Building ISRS (5% damping)
_ _ _ . _ . _ _ _ _ _ _ _ _ _ _ _ . 8me_ RI_. ___A).S_____________________.___
- x .
,ccuo.n . cci.o.,
vi,.mcno.,.. .......
i.. . ..................i.
........m.......................
..,. ,i , , ..............
u..o. .,,........
..1.o
. . s. _ .
. j .9 . . _ _ , ,, . . . , _ _ , . _ , ,
,,_ _ _ . . , 3 4
._ . . __.___ - - _p.A _ . _ Jf G M = g tl. - 2.92 a . 1 1.. 6 ; NR
.. .. ; L. - - - -
- i..
-F e l j '
. l A Desip Bisis ,,,,,
{, ._-. . .T.iir
-=. _.
. _ . . _ . . . . . 3.
to ._ .m ... .._.. . . . . . . . . . . .
l l
.. .n .
. e .. . . . - -
.. _ _ . _ _ . . . . . . j .
q
=.
e
...c (b rpp.T4Rs
\
'. . o.N l
._ _a. ... . ,
,, g,,, . . . . _
_._ .. m .. .
. e ob c.
..s..
j
,, -.p .. . .
. . . . . . ....,. _ . . . 1.E.We,C1 INL9
. n. ...
io.,
fi.e/ ff.T'+ d
- 5.16 .TZ D A!1Pt.sos
_ .HA$1_Poe.sr$~
14 r n Y,4 ~ .I* vr o Denscret 1
, N aro]tg M W rv bpb3 (td NNfin Ak b hsp hv bk == IM S g, .bl. 5,4 i pi,,&w bk == 0.43 d.25 = 0. 3 '#6 t.<..h bek b fhwto l
l l
l l
, l s
f . z.
i
- . . Q ,
0 0 0
n 4
~,, q;. g " ;;f- ,
0 0
1 p =
n k.
p S - ..
m d a ko g.u,___ , .;
ni d u
o e a 3 W*7q. "
(
4 t
rM ^;, N . [$. T w f g, +#~ Za G 'd g t,m.[
y C..
h B5 e
0 t *yhl@
f n 1 j
g oa i
0 .
= .i ~ , i S'.
ns a
g oissi p '- 0 _
s as 0
i 0 _
.-: 0 1
rBy a 6 1 ' 7 d.
WM..
l ' .
pn a II l;x e : .
gn d i
u 7 w#' ,. .)5g .
)
m os i A
- a G. , c j.. H g
e H: - 5 ;.
(
y Ced f
c R 7. n wM'3f$M, l' e
,De d -
c4 u
q n
" j xE r
p.. M':a,.. e a u Dr ote S E s-_)_
_h g
F r
t nf n ad e R
G g
- h
- gp
".;. ' M"..:.
eC abdN'A l '
0 Ps i
~~
't 0 1
.r f
- U o n
0 e L1 .
o .
.. : ~ '
y s
1 s
l+
i r .
a en !-.,}u y.. . wh
~
p r o J' y l i'; .. ;
m .
up o ~~ p 9 i;M i
gs F e C
y ... .
p
}.['
s 53
- n v
A D;. -
R yp_
.. {}-
y"m.y%' -
k g p~ y . gM 0 1
5 3 2
5 g 1 5 O 0 3 -
0 o ' O 0 o 0 0 3.O '
l I ,f