ML20056G797
| ML20056G797 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 08/27/1993 |
| From: | FLORIDA POWER CORP. |
| To: | |
| Shared Package | |
| ML20056G795 | List: |
| References | |
| 3F0893-12, 3F893-12, GL-87-02, GL-87-2, PROC-930827, NUDOCS 9309070177 | |
| Download: ML20056G797 (77) | |
Text
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Crystal River Unit 3 Docket No. 5(Mc2 August 27,1933 3r089312 Anactimord 2 Technical Basis for the Crystal River Unit 3 Plant Specific Procedure to resolve N12C Generic Letter 87-02 isr p
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Table of Contents i
Summary. . . . ii )
Background.. .1
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Approach.. .1 Technical Bases for CR3 Plant Specific Procedure.. .3 l Conclusions.. .7 References.. .7 l i
Table 1 - CR3 Plant Specific Procedure vs GL 87-02 and GIP.. .8 ,
Appendix A - Seismic Demand.. . . A- 1 Appendix B - Raceways.. ..B-1 !
Appendix C - Relays.. . ..C-1 ,
Appendix D - Equipment-Specific Caveats.. ..D-1 Appendix E - Anchorage.. . .. . ..E-1 i
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Summary !
e Florida Power Corporation is required to respond to NRC Generic Letter 87-02, St.pplement 1. FPC's response committed it to develop a Plant Specific Procedure (PSP) ,
for Crystal River Unit 3 (CR3) to resolve NRC's concerns outlined in GL 87-02. t Florida Power Corporation is a member of the Seismic Qualification Utility Group (SQUG) and could use SQUG's Generic Implementetion Procedure (GIP) for the verifi- '
cation of the seismic adequacy of GL 87-02 equipment in CR3. However, it is FPC's [
position that Florida is a low seismic risk state and implementation of the GIP (which was i developed so it could be applied generically even to GL 87-02 plants in the relatively high t seismic areas in the western US)is not in FPC's best interest.
This repon summarizes the technical bases for the CR3 PSP. The detailed CR3 PSP itselfis presented in a separate document.
We believe that the CR3 Plant Specific Procedure is a positive, responsible, and .
prudent response to GL 87-O' All of the key GIP commitments and a large number ofits guidelines are included !
in the CR3 PSP. For most GIP guidelines not specifically included in the CR3 PSP, a site- _;
and plant-specific pre-screening of CR3 concluded that CR3 meets the GIP. For the re-maining GIP guidelines not specifically included in the CR3 PSP, the CR3 PSP includes i guidelines that meet the intent of the GIP. The bases for these conclusions are discussed in this report. ;
For almost all of this pre-screening, the basis is that CR3 is a low seismic site. For !
i example, the CR3 SSE has a peak acceleration of only 0.lg. On the other hand, the GIP was developed so it would be acceptable to NRC even for the GL 87-02 plant with the largest SSE peak acceleration of 0.25g. -
The difference between a 0.lg SSE and a 0.25g SSE is very large. Even a factor i of 2.5 does not adequately convey the differences between these two SSEs. A 0.25g earthquake is a respectable earthquake. A 0.lg eanhquake is hardly so. On a qualitative scale, a 0. lg earthquake probably would cause some slight damage to homes and other commercial and public buildings. On the other hand, a 0.25g earthquake probably would cause moderate to major destruction to homes and other commercial and public buildings. l This report presents technical information to substantiate some of the differences between what is reasonable to expect for a 0.lg canhquake, what is reasonable to expect for the 0.25g earthquake considered in the GIP, and why pre-screening is reasonable.
For example, a GIP caveat limits the size of cut-outs in motor control center cabi-net sheet metal. The GIP concern is structural integrity of the MCC. Since the CR3 SSE i is only 0.lg, the size of cutouts is not considered a credible root cause of damage to CR3 MCCs that are constructed to NEMA standards. In other words, the CR3 SSE is not
large enough to damage CR3 MCCs: Thus, the GIP caveat is satisfied (that is, CR3 MCCs will not be damaged in an SSE).
Finally, as NRC stated in SSER2: "As a result of the backfu analysisfor the US/ i A-46 program, the staffdetermined that the use of the US1 A-46 approachprovides ade- i quate level ofsafety.... "
We believe,like the USI A46 approach in GL 87-02, that the CR3 Plant Specific ;
Procedure provides an adequate level ofsafety, especially when all the ram'!ications of the fact that CR3 is in a low seismic region are considered.
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Background ;
Florida Power Corporation is required to respond to NRC Generic Letter 87-02, ,
Supplement 1. FPC's response committed it to develop a Plant Specific Procedure (PSP) for Crystal River Unit 3 (CR3), based on the GIP, to resolve NRC's concerns outlined in GL 87-02. FPC contracted Gilbert / Commonwealth, Programmatic Solutions, ,
and The Readiness Operation to help develop its plant specific procedure. This re- i port summarizes the technical bases for the CR3 PSP. The detailed CR3 PSP itselfis pre- l sented in a separate document.
t Approach Florida Power Corporation is a member of the Seismic Qualification Utility Group (SQUG) and could use SQUG's Generic Implementation Procedure (GIP) for the verifi- l cation of the seismic adequacy of GL 87-02 equipment in CR3. However, it is FPC's !
position that Florida is a low seismic risk state and implementation of the GIP (which was developed so it could be applied even to GL 87-02 plants in the relatively high seismic ar- -
eas in the western US)is not in FPC's best interest.
With this background, the following two paragraphs briefly describe the two ap-proaches we used to develop the CR3 PSP: (1) Meets the G/P, and (2) Meets the Intent of the GIP.
Meets the GIP. In many cases, the CR3 PSP adopts the letter of the GIP. For i example, the CR3 PSP adopts the GIP implementation guidelines for scismic interaction, i quahfications ofseismic capabihn' engineers, documentation, and many ather detalled :
screening guidelines and caveats. These areas are identified in Table 1 and Appendix D.
Meets Intent of GIP. In the vast majority of the cases where the CR3 PSP does ;
not meet the letter of the GIP, the CR3 PSP meets the intent of the GIP. For almost all of these cases, the reason is that CR3 is a low seismic site. For example, for many electrical l cabinets a GIP caveat limits the size of cut-outs in the cabinet sheet metal. The concern is structural integrity of the cabinet. Since the CR3 SSE is only 0.lg, the size of cutouts is ;
not considered a credible root cause ofdamage to cabinets constmeted to NEMA stan- ,
dards. In other words, the CR3 SSE is not large enough to damage CR3 MCCs and the GIP caveat is satisfied (that is, CR3 MCCs will not be damaged in an SSE).
For the caveats in Appendix B of the GIP however, note that " meets the intent of !
the caveat"is all that is required to meet the GIP (this is discussed in Section 4.1.3 of the ;
GIP). To clarify matters in this report however, Appendix D identifies those caveats where the CR3 PSP meets the intent of the GIP as " meeting intent. " even though we could have stated that the CR3 PSP " meets the GlP However, this is done for the pur-pose of more clearly communicating what the CR3 PSP is, and what it is not. This does ;
not mean FPC does not accept Section 4.1.3 of the GIP.
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, The following five paragraphs describe some of the techniques we used to develop l
[ the CR3 PSP. Note, however, that they all fallinto the above two approaches. ;
J Pre-Screening. In some cases, CR3 PSP guidelines are based on a i pre-screening of the equipment class, or detail, relative to the GIP (or PSP) guidelines, )
and the pre-screening finds that the CR3 equipment or detail meets or exceeds the guide- i lines. This means a case by case screening of the item or class is not required during the l
walkdown or other implementation of the CR3 PSP (since the screening has already been done) For example, Appendix A shows that the seismic capacity of CR3 SSEL equip- ;
ment exceeds the seismic demand on it. Thus,in this case the CR3 PSP is equivalent to i the GIP commitment in Section 4.1 of the GIP, even though a case by case screening will ,
! not be performed during the implementation of the CR3 PSP.
Plant Specific Implementation of GIP Bases. SQUG developed the GIP for application to a wide variety of plants and sites. For example, the GIP was developed so it could be applied to the highest seismic GL 87-02 plants, including some plants in the :
western US. Some GIP implementation guidelines do not vary depending on the size of
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the SSE. This means the GIP implies that the desired seismic margin at CR3 is larger than j l the desired seismic margin at the GL 87-02 plant with the largest SSE. Thus, the GIP l
] does not always adequately reflect CR3 plant and site specific issues.
l In some cases, the CR3 PSP takes credit for plant or site specific issues by l I interpreting the GIP bases (the "research" reports referenced in the GIP), which is allowed j by the GIP. For example, this approach was used, in part, in evaluating the adequacy of CR3 raceway supports. Details are in Appendix B.
l Mccis GL 87-02 (219 87). In some cases, CR3 PSP guidelines are based ,
on NRC's original generic letter. For example, the CR3 PSP implementation guidelines !
! for anchorage are based, in part, on explicit guidance in GL 87-02. Details are in Appen- l' dix E.
NewInformation. In some cases, CR3 PSP guidelines are based on infor- l
- mation that was not considered in developing the GIP. For example, data on the actualin- l
, structure amplifications recorded in earthquakes at nuclear power plants are used to de- !
velop the seismic demand guidelines in Appendix A. This is allowed by the GIP (see Sec-
, tion 5) as long as the bases are documented (which is done in Appendix A).
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Combined Approach. In some cases, combinations of the above ap- :
proaches were used to develop the CR3 PSP guidelines. For example, Plant @ccifeIm-plcmentation of G/P Bases and Pre-Screenmg was used for Raceways. Details are in Ap- (
4 pendix B. !
4 1
i Technical Bases for CR3 Plant Specific Procedure i
Introduction. This section summarizes the technical bases for the guidance in the !
CR3 PSP. The technical bases fall into two major areas: Agrees With the GIP, and Agrecs ;
With the Intent of the GIP. These areas are discussed in the following paragraphs.
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CR3 PSP Agrees With GIP. A large portion of the CR3 PSP agrees with the GIP. Table 1 summarizes the key parts of the GIP, and identifies those areas where the '
CR3 PSP agrees with GL 87-02 or the GIP. The CR3 PSP agrees with the GIP for about b
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75% of the elements of the GIP listed in Table 1. Some of the key areas of agreement are l briefly discussed in the following.
j The four major steps of the CR3 PSP are the same as those in Section 1.3 of the ;
GIP, namely: J
. Selection of Seismic Evaluation Personnel
. Identification of Safe Shutdown Equipment !
. Screening Verification and Walkdown i
. Outlier Identification and Resolution ,
For Selection ofSeismic Evaluation Personnel, the CR3 PSP is the same as the l GIP for Systems Engineers, Plant Operations Personnel, and Seismic Capability Engmeers. j in fact, FPC has already sent several engineers to the SQUG training on the GIP. j For Idenufication ofSafe Shutdown Equipment, the CR3 PSP is the same as the GIP. i i
For Screening Venfication and Walkdown, the CR3 PSP has the same basic four steps as the GIP: !
. Seismic Capcity Compared to Seismic Demand ,
. Caveats
. Anchorage
. Seismic Interaction :
For Outlier Idennfication andResolution, the CR3 PSP definition of an outlier, I and the ways they can be resolved, are identical to the GIP. f Equipment Caveats. Appendix B of the GIP has a total of 266 generic caveats for l the SQUG 20 classes of equipment. The CR3 PSP accepts a.JI 266 caveats (with the un-derstanding that Section 4.1.3 of the GIP applies on " meeting the inrent" of the caveats).
Seventy-nine of the 266 caveats are briefly discussed in Appendix D. Fifty-one of '
the 79 caveats are satisfied by pre-screening, and thus are not included for implementation !
the CR3 PSP. That is, we evaluated the concern that is the basis for the caveat and con- !
cluded that, based on CR3 being a low seismic site, that the concern is not a credible one I
for CR3 equipment. In other words, CR3 meets the intent of the caveat.
The remaining 28 of the 79 caveats are included in the CR3 PSP (all of them are ;
anchorage issues). The CR3 PSP position on anchorage is discussed below. We believe the CR3 PSP approach to anchorage meets the intent of the GIP. ;
In addition, in both the GIP and the CR3 PSP, all classes of equipment include the l caveat: "No other concenn?" Moreover, the Seismic Capability Engineers (SCEs) who :
will perform the CR3 walkdowns will be SQUG trained. Thus, CR3 SCEs will be familiar ,
with all 266 caveats in the GIP Because SCEs must evaluate and answer the question I "No other concerns? " before they leave each item of SSEL equipment, they will evaluate :
any violations of the GIP caveats not included in the CR3 PSP they beheve are important ;
to the safety of each specific item of CR3 equipment. i Where the GIP caveat is included in the CR3 PSP, this is "idennfied only by omis- J sion"in Appendix D. That is, Appendix D identifies only the equipment specific caveats j
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i where there is some difference between the GIP and the CR3 PSP that warrants mention. ;
GIP caveats not in Appendix D are in the CR3 PSP. ;
Imponant differences between the implementation guidelines in the GIP and the CR3 PSP are identified in Table 1 or Appendix D. The remainder of this section summa- ,
rizes these differences and the bases for them. t r
Seismic Demand. Appendix A summarizes the bases for the CR3 PSP guidance on seismic demand. Earthquake data on actual in-structure amplifications recorded at l nuclear power plants were used to develop the seismic demand guidelines in Appendix A. l These data were not considered in developing the GIP. 2 The seismic demand spectra for CR3 SSEL equipment is found to be less than the-SQUG Reference Spectrum (which is the canhquake-experience-based equipment capacity spectrum NRC and SQUG agreed on) for all frequencies. Thus, CR3 SSEL equipment for which earthquake-based seismic capacity is applicable has a seismic j capacity greater than the seismic demand (if the applicable equipment caveats are met). ,
Note that this conclusion applies to the adequacy of only the equipment capacity !
itself. The adequacy of the capacity of equipment anchorage must be determined sepa- !
rately by walking down each item of SSEL equipment (see Appendix E). l This means the implementation of the CR3 PSP for GL 87-02 does not have to address the GIP issue of the seismic capacity and demand of equipment (for that equipment for which earthquake-based seismic capacity is used) on a case by case basis. ;
In other words, the GIP seismic capacity / demand screening guideline is pre-screened by !
the discussion in Appendix A.
This also means that the CR3 plant specific procedure for GL 87-02 does not have to explicitly include the GIP 8 Hz guideline. This is because the GIP 8 Hz guideline is i only needed when a different capacity / demand method is used than the one used in the :
CR3 PSP. (Method A ofTable 4-1 of the GIP is not used in the CR3 PSP. The CR3 PSP ;
uses Method B.1 of Table 4-1. Method A has the 8 Hz caveat, Method B does not.) r This also means that the CR3 plant specific procedure for GL 87-02 does not have :
to explicitly include the GIP guideline of evaluating the stiffness of equipment anchorage !
(for equipment frequencyissues). The GIP anchorage stiffness guideline is pre-screened ;
by the CR3 seismic demand / capacity pre-screening discussed above. (thwever, this does not mean that the base stiffness / prying action issue of Check 12 of Section 4.4.1 of the i GIP is pre-screened. SCEs should still review any base stiffness / prying action details that, in theirjudgment, they need to in their review of equipment anchorage.)
Details arein Appendix A.
Finally, note that the Commitments in Section 4.1 of the GIP do not prescribe how to develop the plant-specific seismic demand. Section 4.1 specifies how to obtain seismic . !
capacity--which the CR3 PSP agrees with, and that seismic capacity must exceed seismic l demand-which the CR3 PSP also agrees with. T/ms. the CR3 PSP approach to seismic capacity demand meets the SOUG Commitment in Section 4.1 of the GIP. ;
I Raceways. In Reference B1, SQUG documented the performance of raceways in canhquakes. Raceways have performed in an outstanding manner, even in eanhquakes over five times larger than the CR3 SSE. This is parucularly impressive considering that Programmatic Solutions 4 Rev 0 6123/93 The Readiness Operation :
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1 the vast majority of these raceways are not designed for eanhquakes, and are instead I constructed to normalindustrial practice. Raceways have a better carthquake ;
performance record thara virtually every other power plant component; this includes !
structures, vessels, piping, equipment, and equipment anchorage.
The primary analytical guideline in the GIP is that raceway supports should have a i vertical capacity of 3 times the weight they support.
The GIP guideline is stated as a vertical capacity check. However, when we de- ,
veloped the venical capacity check for SQUG, we intended the verticahoad factor of 3 to !
account for all applicable earthquake loads, including lateral earthquake loads.
In addition, we intended the analytical guidelines to act as a similarity evaluation. l That is, our objective is to use the analytical guidelines to ensure that CR3 raceway sup-ports are similar to or better than supports that performed well in eanhquakes.
The GlP analytical guidelines were derived from the performance of raceways in earthquakes that were larger (in many cases much larger) than the largest GL 87-02 SSE of 0.25g. To simplify the generic guidelines however, when SSRAP revised our original :
guidelines, they chose not to recommend that the venical dead load seismic factor vary ;
with the size of the GL 87-02 plant SSE. (However, we initially developed the dead load factor to vary with the SSE size. Moreover, other GIP raceway analytical guidelines still ,
do vary according to the size of the GL 87-02 plant SSE.)
When the GIP vertical capacity check of 3 times dead load is revised to vary with the size of the CR3 SSE, we found the existing CR3 raceway design criteria satisfy it.
Other existing CR3 raceway design criteria me:t or exceed GIP guidelines. A briefwalk-l down confirmed that the CR3 raceways are of normalindustrial or even more rugged construction. !
We conclude that the CR3 raceways meet the intent of the GIP, and that a case by case review of the raceway systems at CR3, to the screening guidelines in the GIP or to any other guidelines in addition to the criteria used for design at CR3, is not needed to satisfy GL 87-02.
Details and additional discussion arein Appendix B. !
Relays. Data on the actual performance of relays in past earthquakes are summa-rized in Appendix C. No claim is made that these data are complete in the sense that they ';
describe every instance of earthquake induced relay actuation. In fact, some of the refer-ences in Appendix C allude to insMnces of actuation that are not included in Appendix C i (because the references do not provide any details).
These data are complete in that they include all of the readily available SQUG data.
SQUG is the key group that has studied the performance of power and industrial facilities ;
in past canhquakes. Thus, these are some of the best and most complete data available on !
relay actuations undct real world plant design, plant maintenance, plant operation, i earthquake conditions, and real-world operator response. l These data are most complete in the sense that they provide a good understanding ;
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of the types of relay actuations that have occurred. (Note that the type of earthquake ef-fects included in Appendix C is based on the GIP's definition of " relay charter, " which ,
includes many different kinds of physical phenomena.) l I
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i Appendix C suggests that the canhquake induced relay chatter issue has probably j been overstated for a low seismic site like CR3. One way the issue has been overstated is '
through repons of prosctive relay actuation. While protective relay actuations have oc-curred, they are often nns-interpreted. The actuations often result from current or voltage' (
fluctuations (that were caused by eanhquake induced damage, momentary power line !
shon circuits, or other non-relay effects) or other non-relay fluctuations such as fluctua- l tions in oil level. These protective relays were simply performing as designed. (Stated j another way, even if these protective relays were seismically qualified with very large i seismic margin, they still would actuate in an eanhquake, given the same current, voltage, ;
or other non-relay fluctuations. Thus, they are a system seismic issue not a relay seismic ;
qualification issue, and probably not an A46 issue.) -!
The key findings of Appendix C are that very few, if any, essential relay actuations l should be expected in the event of an SSE at CR3 (because although the CR3 SSE ZPA is ;
conservative it is still only 0.lg, and because only short duration eanhquakes are expected l at CR3), and that operators will be able to take timely action and reset any essential relays j that actuate. i In addition, because the CR3 SSE is so small. CR3 is different from many other !
GL 87-02 plants in that it is very likely that offsite power will not be lost in the event of an l SSE at CR3. This means that CR3 operators prebably will not have to address power ,
restoring problems in the event of an SSE at CR3. This funher suppons our contention l
that operators will be able to take timely action and reset any essential relays that actuate in the event of the CR3 SSE.
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Based on substantial real world data on earthquake-induced relay actuations, the conclusion of Appendix C is that: G3 meets the GIP, and a case by case relay evaluation l program is not required at CR3 to address GL 87-02. See Appendix C for details.
j Anchorage. The CR3 PSP position on anchorage for GL 87-02 (see Appendix E) l is very close to NRC's position in GL 87 32. !
The technical basis for the CR3 position is that the GIP overstates the anchorage l issue for a low seismic site like CR3, which has an SSE with a ZPA of only 0.lg. This is based on data on anchorage damage in past earthquakes, which was not considered in de- I veloping the GIP. f Reference E2 summarizes a site and literature survey of the earthquake perform- i ance of anchorage. For example, Reference E2 documents over 360 cases of anchorage l damage. Only about 20 of the 360+ cases of damage were in power plants. All 20 cases )
occurred when the free field ZPA was 0.25g or more, and the eanhquake magnitude was )
large (greater than 7).
l The conclusion of Appendix E is that it is good conservative seismic design I practice to anchor equipment well. However, Appendix E also concluded that it is not difIicult to design and install anchorage that will perform well in earthquakes. It is also not difficult for qualified seismic capability engineers to usejudgment to evaluate the adequacy of existing anchorage for a relatively minor earthquake like the CR3 SSE.
Earthquake experience clearly suggests that the detailed GIP guidelines are not required for a low seismic site like CR3, and that the CR3 PSP guideline is completely adequate to satisfy GL 87-02 at CR3--and meet the intent of the GIP.
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Tanks. The CR3 PSP requires verification only ofanchorage of vertical cylindri- 4 cal ground mounted storage tanks. This is all that is required in GL 87-02. This is also consistent with the observation from past carthquakes (in Reference 1) that damage in an- .
chored tanks is almost exclusively associated with tank anchorage (that is, anchor stretch ,
or pullout) CR3 PSP anchorage verificaticn requires anchor stretch and pullout to be evaluated. This evaluation is to be performed using calculations (using the methods in the GIP, Reference 1, Reference 2, or any other rational method). ,
i SSER2. We reviewed NRC's comments in SSER2 on the GIP. Almost all of them are not relevant to CR3 or the CR3 PSP. For some, this is because they address is-sues such as modifications and replacements, which are not included in the CR3 PSP. For others, this is because of difTerences in approach or scope. For still others, this is because l CR3, or the CR3 PSP, complies with NRC's comment.
The most imponant difference not included in the above categories is on third party auditors. Here NRC requested that third party auditors have broad engineering ex-perience (in addition to the GIP requirements in Section 2.2.7). The CR3 PSP accepts NRC's request on third part auditors. ;
Conclusions The technical bases for the CR3 Plant Specific Procedure have been presented and l explained. A detailed comparison of the guidelines in the CR3 Plant Specific Procedure i
and SQUG's GIP has been presented to ease NRC's review. The CR3 Plant Specific Pro-
. cedure either agrees with the GIP, or the CR3 plant meets the GIP or its intent. Where the CR3 Plant Specific Procedure differs with the GIP, this is almost always because CR3 ,
is a low seismic site with an SSE ZPA of only 0.lg, whereas the GIP was developed so it l would be applicable even for a California plant with an SSE ZPA of 0.25g. We believe, ;
like the USI A46 approach in GL 87-02, that the CR3 Plant Specific Procedure provides l an adequare /crel ofsafety, especially when all the ramifications of the fact that CR3 is in !
a low seismic region are considered.
1 Referenees i
- 1. P S Hashimoto and L W Tiong: Earthquake Experience Data on Anchored Ground- l Mounted Vertica/ Storage Tanks, prepared by EQE Engineering for the Electric Power !
Research Institute, EPRI NP-6276, March 1989. I 2.1 W Reed, R P Kennedy, D R Buttemer,1 M Idriss, D P Moore, T Barr, K D Wooten, :
1 E Smith: A Methodologyfor Assessment ofNuclear Power Plant Seismic Margin (Revision I), prepared for the Electric Power Research Institute, EPRI NP-6041-SL, Re-sision 1, August 1991.
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Table 1 compares the guidance given in the CR3 Plant Specific Procedure for GL 87-02 with the guidance given in the GIP and GL 87-02.
Table 1 -- CR3 Plant Specific Procedure vs GL 87-02 and GIP i
GIP Guidance GL 87-02 Guid- CR3 Plant Specinc Pro- Basis for ;
ance cedure Guidance CR3 PS Guidance ;
1.1 Purpose. ne pur- Same as GIP Not ne purpose of the FPSP N/A pose of the GIP is to as detailed Not is to summanze p] ant !
summanze gen _ene Fuid- complete. _spenfic Fuidance that can ,
ance that can be used to be used to venfy the i venfy the seismic ade- seisnuc adequacy of se-quacy of selected eqmp- lected equipment follow. ,
ment following a safe ing a safe shutdown !
shutdown canhquake at canhquake at Crystal ,
all GL 8742 plants River Unit 3.
1.3 Approach. He j steps in a GIP evaluation are desenbed. Theyin-clude the following:
Selection of Seismic Does not require Same as GIP. N/A Evaluation Personnel as extensive a ,
(Section 2). bacLFround as the !
GIP.
- Identification of Safe Different functions Same as GIP. N/A ;
Shutdown Equipment specified com- ,
(Section 3) pared to GIP.
Screening Venfication Many difTerences Four basic steps same as See below.
and Walidown (Sectmn m details from the GIP. Some differences in ;
4). GIP. details.
Outlier Identification and included " outliers" Same as GIP. N/A Resolution (Section 5) and "deficencies."
Relay Functionahty Re- Similar to GIP, but Detailed relay review not Appendix !
view (Section 6). not as detailed. required because CR3 C meets the GIP. ,
Tanks and lleat Ex. Tanks and heat Same as GL 8742. For tanks, [
changer Review (Section exchanger anchor- (Evaluate anchorage.) see text of ,
- 7) age included, but mam re- [
no detailed guide- pon.
lines.
(
Cable and Conduit Cable trap m- Pre-screened Appendix ,
Raceway Review cluded, but not B. ;
(Section 8) condmt sptems, but no details.
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Table 1 -(Continued)
GIP Guidance GL 87 02 CR3 Plant Specific Basis for Guidance Procedure Guidance CR3 PS Guidance l
2.0 Introduction. The Similar to GIP Same as GIP. N/A J responsibilities and Not as detailed quahfications of the Not as stringent. f mdividuals who will i tmplement the GIP are defmed in this section.
2.1 SQUG Commit- N/A Same as GIP except for N/A ;
ments. relay reviewers-Conumtments made by licensees are given m r
this section.
2.2 Systems Engineers Systems engmeets Same as GIP. N/A De responsibilities and not specifically qualifications of %e sys- discussed.
tems engineers are de-scnbed in this section. ,
2.3 Plant Operations Similar to GIP. Same as GIP. N/A ,
Personel The respon- Not as detailed ;
sibilities and qualifica-
- tions of the plant opera-tions personnel are given ;
[
in this section.
2.4 Seismic Capability SCEs not defmed Same as GIP. N/A ,
Engineers. He respon- as such. Respon- 1 sibihties and qualifica- sibihties similar to !
tions of the seismic ca- GIP. Quahfica.
pabihty engmeets are tions not as sinn- ,
desenbed in this section. gent.
i 2.5 delay Evaluation Relay evaluauan Relay evaluation persor- . Appendix Personnel The respon- personnel not de- nel not required- C sibilities and capabihties fined as such of relay evaluation per- Responsibilities r sonnel are described in similar to GIP. not i
this section. as detailed as GIP.
2.6 SQUG Training GL B742 imphes Same as GIP. N/A ,
Corrses. Two training trairung requued ;
courses are discussed:(1) only for usik- l Walkdown training doun- j course, and (2) Safe shutdown equipment t selection and relay {
screemng and evaluation.
.Ii l
t F
i f
i Programmatic Solutions 9 Rev 0 6123/93 The Readiness Operation ;
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Table 1 - (Continued)
CIP Guidance GL 87-02 CR3 Plant Specific Basis for Guidance Procedure Guidance CR3 PS Guidance j 3.0 Introduction. This N/A N/A N/A section describes in gen- ,
eral terms the process used to select safe shut-I down equipment and identifies the GIP section that provides the details.
3.1 SQUC Commit- Not as detailed Same as GIP. N/A ments. Comnutments made by licensee are Fi ren in this section.
3.1.1 Identification of Different functions Same as GIP. Ilouever, N/A Safe Shutdown Path. specified com- hie some other GL 87-02 his section requires pared to GIP plants, CR3 does not selection of a safe shut- have some systems that '
down path that ensures allow it to precisely meet that the four essential the GIP redundancy functions of Reactivity guidehnes. l Control. Reactor Coolant Pressure Control, Reac-tor Coolant Inventory Control, and Decay IIcat .
Removal can be accom-plished after an SSE. .
After identifying the safe shutdown path, this sec-tion requires identifica-tion ofindividual items of egwpment to accom-plish the four essential functions.
3.1.2 Assumptions Sunilar assump. Same as GIP. N/A Used in Identifying tions to GIP.
Safe Shutdown Path. Mo&fied single This section identifies failure entenon bounding conditions that only for maintain-must be observed in se- ing safe shindown lectmF the safe shutdown (GIP adds enterion path and equipment. to achieve safe shutdown).
3.3.1 Scope of Equip- Onh 8 of the GIP Same as GIP (except for N/A ment. This section de- 23 classes 65- those classes of equip-fines the 23 classes of cussed. ment not on CR3 SSEL)-
equipment that should be reviewed.
3.3.2 Esclusion of NSSS equipment same as GIP. N/A NSSS Equipment not discussed.
Programmatic Solutions 10 Rev 0 6123/93 The Reactiness Operation
Table 1 -(Continued)
GIP Guidance CL 87-02 CR3 Plant Specific Basis for Guidance Procedure Guidance CR3 PS Guidance i'
3.3.3 Rule of the Box. Rule of the box not Same as GIP. N/A Tlus section explains discussed ;
that it is not necessan to separately evaluate sub.
conents that are part of a ,
component assembly. ;
3.3.4 Active Equip- Similar to GIP Same as GIP. N/A ment This sectmn Not as detailed elaborates on assump-tions in Section 3.1.2.
t 3.3.5 Inherently Rug- Not exphcitly dis- Same as GIP. N/A ged Equipment. This cussed. Probably section elaborates on implicit in GL 87- e equipment types that 02 hnuting its need not be evaluated for scope to active seismic adequacy. equipment.
3.3.6 Equipment in Need to include Same as GIP. N/A Supporting Systems. supportmg equip-This section tequires ment mentioned equipment in systems but not discussed.
that support safe shut-down equipment to be {
identified.
3.3.7 Equipment Sub- Not explicitly dis- Case by case review not Appendix ject to Relay Chatter. cussed in detatl. required. Relays are pre- C 1his secuon elaborates Probably imphcit. screened.
on assumption 7 of Sec-tion 3.1.2.
3.3.8 Instrumentation Not explicitly dis. Same as GIP. N/A This section outlines cussed. Probably identification of mstru- imphcit m GL 87 ments to confirm that the 02.
plant is in a safe shut-down condition and to control safe shutdown equipment.
3.3.9 Non-Safety Non-safety grade Same as GH'. N/A Grade Equipment. equipment not This section pernuts non- exphcitly ad-safety grade equipment dressed.
to be include,i in SSEL, provided its operation is covered by procedures.
)
i Programmatic Solutions 11 Rev 0 6/23/93 The Readiness Operation 1
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i Table 1 - (Continued)
GIP Guidance GL 87-02 CR3 Plant Specific Basis for ;
Guidance Procedure Guidance CR3 PS j Guidance j 3.3.10 Tanks and Heat Scope hmited to Same as GL 87-02. For tanks, Exchangers. This sec- cvaluation of (Evaluate anchorage ) see main ,
don explams the need to adequate report. _;
evaluate tanks and heat anchorage. i exchangers required for ;
i 3.3.11 Cable and Con- GL 87-02 included Pre-screened. Appendix ;
duit Racewsys. This cable trays but not B L section explams the need condmt systems ;
i to evaluate cable and conduit raceways.
3.4 Safe Shutdown Different functions Same as GIP. N/A ;
Functions. This section . specified com-describes the actions pared to GIP. .
necessary to satisfy the i four safe shutdown func- ,
tions dermed in the GIP.
3.5 Safe Shutdown Not discussed in Same as GIP. N/A i Ahernatives. This sec- detail.
tion discusses typical f alternate methods to ac- t complish the four safe shutdown functions in Section 3.4. ,
3.6 Identification of GL $7-02 similar Same as GIP, except for Appendix Equipment. This sec- to GIP, but not as relays C ten sununanzes the five detailed.
steps used to idenufy safe shutdown equip-ment.
t 3.7 Operations Review Not m GL 87 02. Same as GIP. N/A of SSEL This secuon suggests methods for revieuwig the SSEL for :
compaubility with plant '
shutdown procedures.
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3.8 Documentation. Not required by Same as GIP. N/A This section decribes the GL 87-02.
. documentanon of the t selection of safe shut-down systems and ,
equipment.
4.0 Introduction. This Same as GIP. Same as GIP. N/A p section desenTes the four elements of the screemng ,
verification and walk-down (see 4.2,4.3,4.4, and 4.5 for detailes).
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Table 1 - (Continued) i CIP Guidance GL 87-02 CR3 Plant Specific Basis for i
Guidance Procedure Guidance CR3 PS -
Guidance l 4.1 SQUG Not in GL 87-02. Same as GIP. (Our N/A i Committments. readmg of Section 4.1 is !
Licensee committments that the CR3 PSP i are given m this section satisfies it.)
4.2 Seismic Capacity- Same as GIP, ex- Same as GIP. Ilowever, . Appendix Demand his section cept casher carth- not done on a case by A addresses the comparison quake expenence case basis. Already pre-of seismic capacity with Reference Spectra screened. ;
demand for the equip. were used. ,
ment itself. !
4.3 Equipment Class Similar to GIP, not Some GIP caveats not Appendix Similarity and Caicats. as detailed. Only included because of pre- D To use the screening some equipment screemng Anchorage guidelmes in the GIP, the classes exphcitly caveats included but refer equipment charactenstics addressed to CR3 PSP a moach. ,
should be similar to the carthquale experience ;
equipment class, or l GERS class, and must !
meet the intent of the specific caveats for the equipment class. 1 f
4.4 Anchorage Ade- Smular to GIP, Same as allowed by GL Appendix quary. Guidance is except that GL 87- 8742. E provided to screen an- 02 exphcitly al-choraFe based on inspec- lows anchorage ,
tion, analy sis, and engi- adequacy to be !
neenng judgment. evaluated solely by <
judgment.
4.5 Seismic Interac- Similar to GIP, Same as GIP. N/A tion. He fmal screenmg except that details step is to evaluated are not provided.
seismic mteraction.
4.6 Documentation. Not addressed in Same as GIP. N/A This section specifies detail. ,
documentation for the screemng verification
[
and ulldown.
~
5.0 OutlierIdentifica- Outlier defined Same as GtP. N/A tion and Resolution. same as GIP. No j T1us scetion dermes details on
" outliers," and how they dxumentation or ,
should be documented resolution and resolved.
I e
Programmatic Solutions 13 Rev 0 6123/93 The Readiness Operation
Table 1 - (Continued)
GIP Guidance GL 87-02 CR3 Plant Specific Basis for Guidance Procedure Guidance CR3 PS Guidance 00 Relay Functionality Similar to GIP, not Case by case review not Appendix Review. Ilus section as detailed required Relays are pre. C describes how to perform screened a relay rergw.
7.0 Tanks and llent Scope imuted to Same as GL 8742. For tanks, Eschangers. This sec- evaluation of ade- see text of tion describes the review quate anchorage. main re-for tanks and heat ex- port.
changers.
8.0 Racensys.11us included, but no Case by case review not Appendix section describes the details. required. Raceways are B raceway review. pre-screened.
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Programmatic Solutions 14 Rev 0 6123/93 The Readiness Operation
Appendix A - Seismic Demand 1
)
Introduction. This appendix describes the approach used to develop the seismic j demand for evaluation of GL 87-02 equipment at CR3. First, note that the SQUG com. !
mitments in the GIP do not prescribe how seismic demand is to be obtained. - The guid- l ance portion of the GIP does suggest ways an acceptable seismic demand can be devel- l oped, but the GIP clearly allows the use of alternative methods. If alternate methods are j used, then the licensee is requested to maintain their bases at the plant site for NRC review j (but prior NRC approval is not required).
However, this appendix goes beyond the GIP, in that through it FPC is advising :
NRC of the approach used for seismic demand at CR3 for A46 prior to its use in the plant ;
i evaluations and walkdown.
i CR3 In-Structure Spectra. The following figure summarizes the SQUG Refer- i ence Spectmm and CR3 in-structure response spectra (5% damping) at elevations 187 and j 162.
f Figure A1 - CR3 In-Structure Spectra ;
and SQUQ Reference Spectrum i 1.2 , * *
+ SQUG Reference f Spectrum - l
[ -controi sing tar 1- 4 ,
p ,, , --&- Aux Bldg 162' .
.9 j 0.6 - ,
0.4 - , h
- 0. _ _
0 30 '
0 5 10 15 20 25 Frequency,Hz Figure Al shows that the CR3 in-structure spectra are less than the SQUG Refer-ence Spectrum, except around about 11 Hz to 19 Hz at Auxiliary Building elevation 162 ,
(67 f1 above free field grade). There are three items of CR3 SSEL equipment at elevations l where in-structure spectra exceed the SQUG Reference Spectra. Thus, except for these three items of equipment, the agreed-upon SQUG-defined seismic capacity of the CR3 SSEL equipment (that is, the SQUG Reference Spectrum) exceeds the seismic demand on ,
it. In other words, except for three items of SSEL equipment the CR3 SSEL equipment meet the GIP capacity / demand screening guidelines and commitment.
i The purpose of the following discussion is to explain the technical basis for more realistic, but pessimistic, CR3 in-structure spectra at frequencies around about 11 Hz to i 19 Hz where the calculated CR3 in-structure spectra in the Auxiliary Building at elevation ,
f 162 exceed the SQUG Reference Spectrum. The result of this discussion is that all CR3 i
Programmatic Solutions A-1 Rev 0 6123/93 The Readiness Operation -
l SSEL equipment, including the three items mentioned in the presious paragraph, meet the l GIP capacity / demand screening guidelines and commitment.
Earthquake Data. Data on amplifications recorded in carthquakes (References l Al and A3) will now be used to illustrate the pessimism in the calculated CR3 in-structure - l spectra, and to obtain insight on an appropriate seismic demand for the three items of !
equipment in the CR3 auxiliary building at elevation 162 (which is 67 ft above free field). ,
The data are from a number of different earthquakes with free field ZPAs in the l range of 0.01g to 0.13g Thus, the data are appropriate for a low seismic site like CR3, which has an SSE ZPA of only 0.lg. !
Only one set of data are available where horizontal earthquake recordings were i' made in thefreefield and in nuclear plant structures. The data are for measurements in three different reactors in Japan. The three reactors recorded 19,18, and 14 earthquakes, :
respectivay. -Typically, more than one recording was made in each carthquake (for ex- l ample, the earthquake motion was recorded in the two horizontal directions at a specific l in-stmeture or free-field location.) In-structure recordings were made at 20 and 127 fl ,
above the free field.- Figure A2 is a plot of amplification versus frequency for these two elevations. Amphfication is defined as thefrequency byfrequency quotient af the re- l cordedin-structure spectra (5% damped) at elevation (20 fl or 127 ft) and the recorded l freefieldspectra, versus frequency. ,
Figure A2 -In-Structure Amplifications from Earthquake :
Data l TA ' I
--$--20 ft above free
- g. field
---5--127 n above tree E
I' field .
?
j 0.s .
0.s . _ _ = l OA. ^????? O 0.2 -
- I a
O 5 10 15 20 ,
Frequency, Hz I
The data in Figure A2 show that the maximum recorded horizontal amplification is j about 1.4 at 127 ft above free field. The amplification at 20 ft is based on the average 1 of 48 records, while the amplification at 127 fl is based on the average of 71 records. Statis-tically, since the amplifications are based on such a large number of records, this means that the amplification estimates are robust. ,
l t
- 1. The basis for using the average is discussed in detail below. l f
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These data are from a reactor building at a soi/ site. However, CR3 is a rock site. ;
Therefore, to use these amplifications at a rock site like CR3 we must correct them for the j effects of the different foundation materials (rock instead of soil). This is usually assumed !
to mean the amplifications in Figure A2 for a soil site will be increased if the same earth- J quakes had occurred at a rock site. However, there are data that do not support this as-sumption. See the section below titled " Confirming Earthquake Data " Nevenheless. in j this section we will proceed using the assumption that because CR3 is a rock site the am- s plifications in Figure A2 must be increased to apply them to CR3. )
Working backwards, the amplification of the CR3 5% damped free field SSE :
spectra that will ensure CR3 in-structure spectra are below the SQUG Reference Spec- i trum is a factor of about 5 at the closest point (at 33 Hz). In other words, the free field to ;
in structure amplification at CR3 would have to exceed 5 for the m-structure spectra at l CR3 to exceed the SQUG Reference Spectrum. j It is prudent to expect that, even at a low seismic rock site like CR3, the maximum in-structure amplification around 11 Hz to 19 Hz might exceed that shown in Figure A2 ;
(which is for a soil site). However, it does not appear to be reasonable to expect it would i exceed 5. Thisjudgment is reinforced considering that the larger amplification curve in Figure A2 is for an elevation of 127 fl, which is about double the elevation of 67 ft for the t three items of SSEL equipment ofinterest in the CR3 auxiliary building. l NRC Analytical Studies. Thisjudgment is reinforced by the analytical studies in !
Reference A2. These studies assessed the sensitivity ofin-stmeture spectra in a typical shear wall saucture for a variety of foundation conditions (very soft soil to infinitely rigid rock), embedded versus surface founded structure, and 110 fl of soil over bedrock versus half space of soil or rock. The following results are from Reference A2.
The sensitivity study result is that in-structure spectra peaks around 11 Hz to 19 Hz at a rigid rock site would be amplified c worst case 2 multiplicative factor of 4.9 over in-structure spectra peaks calculated at a soil site. This result assumed very soft soil (a half space with a shear wave velocity of 500 fl per second-fps), which is not considered to be representative of the soil in the sites where the data in Figure A2 were recorded.
For the next soflest soil condition,1,000 fps (which is more representative of the soil properties for the Figure A2 data-see Reference A3), the above worst case factor be-comes 3.4 instead of 4.9.
In addition, these results compare 2% damped spectra. We believe the factors would be reduced below 4.9 to 3.4 if the sensitivity study had compared spectra with damping at the GIP damping of 5%.
If the rock is not assumed to be infinitely rigid, but to have a relatively stiff shear wave velocity of 3,5003 fps, the factors of 4.9 and 3.4 (relating the quotient of the amplifi-cation of an infinitely rigid site and the amplification of a soil site) are 2.5 and 1.8, respec-tively.
- 2. The following defines " worst case"- comparisons are made at the top of building, worst soil conditions (softest) are selected, and worst physical conditions are selected (half space and embedded foundation assumption for the soil case. infmitely rigid rock for the rock case).
- 3. 3,500 fps is the next stiffer foundation stiffness available in the sensitivity study.
Programmatic Solutions A-3 Rev 0 6123193 The Readiness Operation
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The sensitivity study factors of 2.5 to 1.8 are considered to be acceptable and . :
probably pessimistic factors for the rock conditions at CR3 versus the soil conditions in the eanhquake data in Figure A2. This means that, around about 11 Hz to 19 Hz, the earthquake amplifications shown in Figure A2 for a soil site are not expected to be ampli-fied more than about 2.5. Thus, the total amplification of the CR3 SSE spectra around l about 11 Hz to 19 Hz is the factor of 0.53 from the data in Figure A2 times the factor of 2.5 from the analytical studies, or a total amplification of about 1.3. Since an amplification i of1.3 around about i1 Hz to 19 Hz is less than the maximum tolerable amplification of 5 discussed above (obtained by working backwards), this means that more realistic, but still pessimistic, CR3 in-structure spectra around about 11 Hz to 19 Hz are less than the SQUG Reference Spectrum.
Note that this result applies up to about 127 ft above free field. This is one indica- !
tion of the pessimism in the calculated CR3 in-structure spectra. Another indication of ,
pessimism is that the above evaluation found the amplification around about 1I Hz to 19 Hz to be at most 1.3, while the calculated in-structure spectra have an amplification of almost 10 at some frequencies.
Thus, combining these results (in the range of about 1I Hz to 19 Hz) with those in Figure Al (for all other frequencies) suppons the above judgment that, for the low seismic CR3 SSE of L Ig, the CR3 structures will not amplify the CR3 SSE free field motion so !
the in-structure motion at the three SSEL equipment locations exceeds the SQUG Refer-ence Spectrum. In shon, CR3 SSEL equipment meet the GIP guidelines and commit- -
ments and seismic demand and capacity.
Confirming Earthquake Data. The above evaluation is based on an approach !
that combined results from canhquake data and analytical sensitivity studies. The follow- ;
ing evaluation of new data provides an independent check on this approach. ,
The new data describe the quotient of the p_eak of the 5% damped in-structure ;
spectra
- and the ZPA at the top of the basemat, which the authors of References A3 and ;
, A4 called the total amplification factor (TAF). These data are from accelerometer record- .
ings made in nuclear plant structures in earthquakes (References A3 and A4). The data !
are for free field ground ZPAs of 0.0lg to 0.14g. The earthquake magnitudes ranged !
- from 4.2 to 7.4. Thus they are appropriate, and probably pessimistic, data for the low seismic conditions at CR3. Records were obtained from a total of 28 separate stmetures l and 30 different eanhquakes.
These amplification data reflect at least three pessimisms: (1) they do not account i for the beneficial effects (even at a rock site) of soil structure interaction, (2) the amplifi- ,
cations are relative to the ZPA at the top of the basemat rather than relative to the ZPA at i the ground surface (which is the relation ofinterest here), and (3) Reference 3 found that ;
- the TAFs for a rock site (CR3 is a rock site) are less than those in Table A1. With these ,
- cautions, Table Al displays the TAF results. The column marked "CR3 Sa"is the peak 5% damped in-structure spectral acceleration at the indicated height above basemat ob-
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- 4. Unfonunately, the frequencies of these spectral peaks have not been published. ;
Programmatic Solutions A-4 Rev 0 6123/93 The Readiness Operation l s
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The values in the "CR3 Sa" column are obtained by multiplying the values in the "TAF' column by O.1. ;
Table Al--Total Amplification Factor (TAF) From Earthquake Data l Structure Height Above No. of TAF CR3 Sa [
Basemat (ft) Data !
- 5. Int Conc 20 8 3.9 0.39 ,
- 6. Int Conc 35 6 6.4 0.64
- 7. Int Conc 50-75* 20 8.5 0 85 !
- 8. Turb Bldg 60-70* 41 9.3 0.93 :
- 9. Aux Bldg 35 6 4.6 0.46 l'
- 10. Aux Bldg 90 6 5.3 0.53
- 11. Aux Bldg 115+ 6 11.4 1.14
- Operating floor j Note that all the above CR3 Sa values are less than the 1.2g peak of the SQUG ;
Reference Spectrum (even though the CR3 Sa values are pessimistic), regardless of the :
elevation of the spectra are above the basemat. However, because the frequencies at ,
.,hich the spectral peaks occurred have not been published, we cannot state with cenainty that the CR3 Sa values in Table Al do not exceed the SQUG Reference Spectrum around !
those frequencies. However, these results do not contradict the previous results, as they l would, for example, if CR3 Sa values were found that exceeded 1.2g. ;
The LR3 Auxiliary Building elevation 162 is about 67 ft above the basemat. Eight i of the 11 results (Items 1, 3, 5, 6, 7, 8, 9, and 10) are in the range of 67 ft above the basemat or somewhat higher, and their CR3 Sa is 0.93g or less, which is less than the ,
SQUG Reference Spectrum peak of1.2g. Thus, these data tend to confirm the results in the presious paragraph.
The SQUG Reference Spectrum has a minimum amplitude of about 0.6g in the ;
range of 1I Hz to 19 Hz. Five of the 8 results (1,3, 5,9, and 10) have CR3 Sa values ;
that are less than this. Note that this includes both of the auxiliary buildings (which is the CR3 structure ofinterest here). These results suggest that it is highly likely that the ;
I SQUG Reference Spectrum envelops more realistic, but still pessimistic,i -structure spectra around 11 Hz to 19 Hz in the CR3 auxiliary building at elevation 162 and below. ]
This confirms the earlier result, which was based on data and analytical studies. i Definition of Amplification. The amplification results illustrated in Figure A2 are obtained by averagmg the amphfication quotients descriued above over the indicated number (48 or 71) of different earthquake records, frequency by frequency. Similarly, Programmatic Solutions A-5 Rev 0 6123193 The Readiness Operation
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Reference A2 calculated amplification as the average of the quotients from 10 analyses (10 different free field time histories were input to the soil structure interaction analyses). ,
Amplification is properly defined as an average (of the quotients). That variations '
in in-stmeture "amphfcation" are obtained from one time history to another does not '
imply that the capability of the stmeture to amplify motion varies from one earthquake to another. This can be seen the easiest from antlytical studies where the analytical model of the structure is exactly the same from one analysis to another, yet variations in !
" amplification" s esult when different time histories are used as inputs to the analysis (see l the discussion below on Figure 11). ;
The apparent variations in arnplification are a consequence of variations (from one [
time history to another) in the relative strengths of the frequency content (from one fre-quency to another) of the earthquake motion input to the building. The variations in the input motions are typically random in nature and reflect a property of the time histories rather than a property of the building amplification. 3 i
The variations in frequency content are already regulated by NRC. NRC does this by requiring plant design spectra to be a smoothed curve derived from response spectra from a mimber of real or realistic earthquakes.
In the past, NRC has typically not regulate this phenomena further. For example. l NRC could require utilities to perform 10 different soil structure interaction analyses ;
(where each of the 10 analyses used a different input time history and calculated in-structure spectra at every iri-structure location and direction for each of the 10 analyses), :
and then take the mean, or mean plus one standard deviation of, for example, the calculated 10 in-structure response spectra. However, NRC does not require this added conservatism, or others, to account for the phenomena of variation in in-structure spectra.
Since NRC does notfurther regidate thisphenomena, this suggests NRC criteria implicitly accept the average in-structure spectra.
To see why this is so, assume 10 identical plants at 10 different sites perform soil ;
structure interaction analyses according to current NRC criteria. Each plant uses a j different input time history in their soil structure interaction analysis. Assume there is no -
bias in selecting the 10 input time histories, and that they are randomly selecteu (NRC i
criteria allow this as iong as each of the time histories mr.tch the plant design spectra according to NRC criteria).
If the resulting 10 different in-structure spectra at any given in-structure location and direction in this hypothetical example are plotted on a single figure, they will exhibit j considerable variation. This is well documented 5 ;
Any of the 10 in-structure spectral values in this hypothetical example is acceptable to NRC, including the smallest one. Since the average of the 10 in-structure spectra is ,
larger than the smallest acceptable value, the average value must also be acceptable.
- 5. For example, see Figure 11 of Reference A4-which plots the upper and lower bounds of 3,072 spectra instead of"only" 10. Figure 11 shows that variations in in-structure spectra of more than a factor of 2 are ,
possible with 2% daraped spectra. In Figure 11, the mannium variability is a factor of 2.36 at about 3.5 .
HL Figure 11 is included on Page A-9 for the convenience of the reader.
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Programmatic Solutions A-6 Rev 0 6123/93 The Readiness Operation
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i NRC implicit acceptance of average in-structure spectra is equivalent to defining amplification using an average. l The GIP agrees with this. For example, Section 4.2.4 of the GIP contains the j following: f t
" *Reahstic, median-centered' m-structure response spectra are defined l as response spectra u hich are based on (1) realistic damping levelsfor the structure and the effects of embedment and u ave-scattering, and (2) i structural dynamic analysis using realistic, best estimate modehngpa- 1 rameters and calcidation methods such that no intentional conservatism {
enters mio theprocess. " (underline added) {
r s
Section 4.2.4 of the GIP also refers to Reference A4--the same reference from )
which Figure 1I was obtained-in defining realistic, median-centered spectra.
The terms " realistic, " " median-centered " and "best estimate," are all consistent f with the above use of the average (or mean) to define amplification for the CR3 A46 - l seismic demand. ,
l Conclusion. The seismic demand spectra for all CR3 SSEL equipment, including i SSEL equipment at elevation 162 or below with frequencies around 11 Hz to 19 Hz,is l found to be less than the SQUG Reference Spectrum (which is the NRC accepted equip- ;
ment capacity spectrum based on eanhquake experience) for all frequencies. Thus, all ,
CR3 SSEL equipment is considered to have a seismic capacity in excess of the seismic demand (if all applicable equipment caveats are met). Note that this conclusion applies l
. only to the adequacy of the capacity of the equipment itself. (The adequacy of the capac- ;
ity of equipment anchorage must be reviewed separately for each item of SSEL equip- - :
i ment, as discussed elsewhere in this report.)
This means the CR3 plant specific procedure for GL 87-02 does not have to ad-dress the GIP issue of the seismic capacity and demand of equipment on a case by case ,
basis. The GIP seismic capacity / demand screening guideline is satisfied by the above dis-cussion. >
This also means that the CR3 plant specific procedure for GL 87-02 does not have to explicitly include the GIP 8 Hz guideline. The GIP 8 Hz guideline is satisfied by the CR3 plant specific conditions discussed above.
If any GERS are used in the CR3 A46 evaluation, the CR3 calculated in-structure spectra will be used for the seismic demand at the in-structure location and direction.. ,
i Programmatic Solutions A-7 Rev 0 6123/93 The Readiness Operation
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< References for Appendix A l Al. Seismic DemandStudy Status Report, presented at SSRAP/SQUG Steering Group !
- Meeting by URS/ John A Blume & Associates, March 30,1988. j I !
i A2. J J Johnson, E C Schewe, O R Maslenikov. SSI Response of a 7ipicalShear Wall l Structure: In-Structure Response Spectra Comparisons, prepared by Structural Mechanics i Associates for Lawrence Livermore National Laboratory as part of the NRC's Seismic l' Safety Margins Research Program, SMA #12209.23.02, April 1984. ,
j A3. D P Jhaveri, R M Czarnecki, R P Kassawara A Singh: Seismic DemandEvaluanons j Based on Actual Earthquake Records, proceedings of the Second Symposium on Current i Issues Related to Nuclear Power Plant Structures, Equipment, and Piping. Orlando, De-
- cember 1988.
l l '
A4. S E Bumpus, J J Johnson, P D Smith: Best Esnmate Method vs Evaluation Method: i A Comparison of Two Techniques in Lvaluating Seismic Analysis andDesign, prepared l by Lawrence Livermore National Laboratory for the US Nuclear Regulatory Commission, ;
NUREG/CR-1489, May 1980. !
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m
MATHEMAllCAL M3, DEL FOR MAIN STEfM VALVE HOUSE & OUENCH SPRAY AREA KEY = 3 NODE = 6 DIREC110N = 1 DT = 0.0100 SEC CODE = 02/15/SOR STRUCTURAL DWPING IN ALL M7ES 5.0% AVERAGE DVFV SROCENED 15%
,I 50 L THE WW MW l (OVER1.0HZ) '
0F THE RATIO Of THE l
45 W AND WN N.M . .
SPECTRA 15(ATI) ,
2.36 l l
40 -
I ,
i 35 ;
i 30 -
/(W -
A i tt k.
25 -
E -
h 1 l 20 -
[, j '
I '
15 -
10 -
S- ,
'r 0
N n
- o osm n m
- in C N M N n 4 0 C AM {
"o
~
Io o o- -
i MAX. MEAN + MIN. ACC. SPECTRA (RG E0, GEES) VS FREQUENCY (HZ) 2.0% DWP :
Figure 11 from Reference A4 l I
Programmatic Solutions A-9 Rev 0 6l23193 Tbe Readiness Operation 1
Appendix B - Raceways Introduction. As NRC notes on page 10 ofits SSER 2 for GL 87-02 (and SQUG t has agreed ta for some time): "The staff acknouledges that these responsible mdividuals l must exercisejudgment to implement the USl A-46 program. The review engineers should utih:e the technicalinformation m the GIP-2 and the reference documents to the maximum extentpracticable in determimng the seismic adequacy ofequipment. Where i judgments are needed:o make these determinanons, the assumptions and basisfor the judgmental conclusions should be documentedas requiredin GIP-2 or idennfied in this supplement. "
The purpose of this Appendix is to describe the technical bases for thejudgment that a case by case review of the raceway supports or systems at CR3, to the screening guidelines in the GIP or to any other guidelines in addition to the criteria already used at ,
CR3, is not needed to satisfy GL 87-02.
To suppon this judgment, this Appendix uses the following approach:
- 1. Previous raceway earthquake and test experience is briefly reviewed. The conclusion :
is that raceways not designeo for earthquakes have an excellent performance record in past earthquakes and tests. Because the CR3 SSE is much smaller than virtually all of the earthquakes in the raceway earthquake experience, and because a brief walkdown of CR3 raceways revealed they are of normal industrial construction (non-safety re-lated systems) or of obvious r"gged seismically-designed construction (safety-related systems), our conclusion is that CR3 raceways meet the intent of the GIP (that is, there will be no loss of electrical cable function in the event of an SSE at CR3). Thus, a case by case review of the raceway supports or systems at CR3, to the screening guidelines in the GIP, or to any other guidelines in additional to the criteria already used to construct the raceways at CR3, is not needed to satisfy GL 87-02. :
- 2. The previous raceway seismic design effons at CR3 are briefly - *l. Since these CR3 raceways were originally designed, and were later re-ev- eted, h 'rthquakes, our conclusion is that these CR3 raceways will perform ever .ater 0 .a the naceways in past earthquakes (which typically had no seismic design). ho~ver, note that this .
review is strictly supplemental to the conclusion in (1), which is based on the perform- ;
ance of raceways in past earthquakes and tests, and its implications to CR3 raceways, particularly considering the construction of CR3 raceways and that CR3 is a low seismic site.
i
- 3. Analytical evaluations are performed on the bases for the GIP raceway screening guidelines, and GIP-like guidelines developed that are appropriate for CR3, specifi-cally considering that CR3 is a low seismic site. The CR3 raceway seismic design cri- -
teria are also reviewed and interpreted in terms of the GIP guidelines. Again however, note that this review is strictly supplemental to the conclusion in (1), which is based on the perfonnance of raceways in past earthquakes and tests, and its implications to CR3 Programmatic Solutions B-1 Rev 0 6/23/93 The Readiness Operation
I raceways, panicularly considering the construction of CR3 raceways and that CR3 is a l low seism 2 site. j i
Earthquake and Test Experience. SQUG documented the earthquake perform-i ance of raceways in Reference Bl. Raceways have performed in an outstanding manner, even in eanhquakes whose free field ground response spectra were over five times larger than the CR3 SSE free field ground response spectra. This is panicularly impressive con- l sidering that the vast majority of these tsceways were not designed for earthquakes.
Raceways have a better earthquake performance record than vinually all other power i plant components, including structures, components, piping, equipment, and equipment anchorage. l The large capacity of raceways constructed to normal industrial practice to with- j stand seismic loads appears to be a result of the many sources of nonlinear behavior. !
In addition, many raceway systems are supponed overhead. For example, most l CR3 raceway suppons are of trapeze construction. As trapeze suppons displace laterally l in an canhquake, the weight of the trays or conduit causes restoringforces that tend to, j and ultimately do, return the displaced system to its at-rest position. Unless the primary .
vertical load carrying capacity of supports is compromised by the lateral or longitudmal displacement (the venical earthquake motion alone does not appear to be very capable in j causing damage to supports), raceway systems will simply swing or displace back and forth like a pendulum until the eanhquake is over (if the complex network-like layout of .
the system will even ahow them to displace). (Many CR3 suppons are even better off l than this since they have engineered antiseismic lateral and longitudinal restraints to limit !
lateral displacement.) l The potential for network effects to restrain real raceway systems is evidenced by j the lack of observations oflateral or longitudinal displacement of real non-seismic raceway systems in earthquakes. (This is contrasted with non-seismic piping systems, which have noted to displace several inches or more.) Because of their limited physical extent, even ;
large scale raceway system tests are unable to realistically simulate these network effects. !
The one instance of raceway structural collapse due to lateral inenial loads oc- l curred in cantilever construction Here, cable trays were supponed from below, where the ,
weight of the cable trays tends to displace the support and cable trays even further once the horizontal canhquake forces displaces the system laterally. Thus, in this case the !
weight did not cause a restoring force, and instead ultimately caused the system to col- }
lapse. Even in this case however, no loss of cable function was found (every cable was i tested for electrical function after the original trays were re-installed and placed back into j service). As noted above, most CR3 supports are of trapeze not cantilever construction. i Shake table tests oflimited test portions of raceway system support the conclu-sions based on the excellent earthquake performance history of real, large scale, raceway systems. One particularly revealing series of tests (for another utility, not Florida Power ,
Corporation) shook the same relatively large scale cable tray test system with and without lateral bracing in place. The primary difference in performance is that the lateral cisplace-ment of the braced system was less than the unbraced system. Since the venical suppons l were ductile, the lateral displacement of the trays did not compromise the primary vertical 1 i
Programmatic Solutions B-2 Rev 0 6123/93 The Readiness Operation i t
load carrying capacity of the suppons. Thus, even though the shaking level was very high, neither the braced nor the unbraced test system wu damaged or collapsed.
Thus, for a low seismic site like CR3, the outstanding canhquake performance of raceways constmeted to normal industrial (non-seismic) practice suppons the conclusion that a case by case review of raceways at CR3 is not required to satisfy GL 87-02. ;
This conclusion is reinforced considering the CR3 raceways that were initially de-signed for earthquakes, which were since been re-evaluated and modified in the light of the evolution of raceway criteria since their initial design and construction.
In thefollowing, we present a variety ofanalyticalinvestigations. However, we present them only as supplementary mformation to ourjudgment (see above) that a case by case review ofraceways at CR3 is not required to satisfy GL 87-02, particularly con-sidering that CR3 is a low seismic site. We believe the analyticalinvestigations support thisjudgment.
GIP Analytical Guidelines. One GIP analytical guideline is that raceway sup-ports should have a venical capacity of at least 3 times the weight they suppon (3xDL).
(The GIP also has a dead load check, and, for cenain support types, a lateral load check.
The lateral load check is discussed in deta3 in a subsequent section.)
The GIP guideline is stated as a vertical capacity check. However, when we de-veloped this guideline, we intended the vertical capacity check (using a derived static load factor of 3xDL) to account for all canhquake loads on the supports, including venical, lateral and 1p_ncitudinal earthquake loads. In cases where a more conventional earthquake engineering approach was used to design the raceways, where raceway supports are de- ,
signed to have lateral and longitudinal load resistance (as is the cast for many supports at CP3), we did not intend that the venical capacity check of 3xDL be used. i Thus, for some support types, the G1P guidelines require a dead load check, a ver- ,
tical capacity check, and a lateral load check. The GIP has the curious effect of penalizing l some plants, including CR3, that have raceways that were designed for canhquakes from the beginning. The reason this happened is that the GIP guidelines were primarily de-t signed to resolve the generic problem ofraceway systems that had no seismic design.
in addaion, we intended the analyticalguidelines to act as a similarity evalu-ation. That is, our intent was that the analytical guidelines would ensure that CR3 race- i way supports are similar to or better than suppons in the earthquake data base that per-formed well. In other words, we did not intend the GIP analytical guidelines to serve the nme function as normal structural engineering calculations.
We proposed a venical capacity factor to evt.luate similarity because of the large number ofparameters8 that would otherwise have to be considered to evaluate the physi-cal similarity of raceways in nuclear plants to those in the earthquake data base. We co*
cluded a similarity evaluation would be impracticable ifit was based on comparing such .
large number of parameters. We developed the vertical capacity check as a substitutefw i a similarity evaluation. (Thus, a traditional eanhquake resistant design, as at CR3, is as '
good and probably better than a similarity evaluation.) At the same time, we felt the verti- 1
- 1. For example, support type, suppon construction, suppon dimensions. suppon spacing. number of trays ,
per support, tray size, tray loads, tra) eccentricity, number of conduit per suppon. size of conduit, suppon bracing. system bracing, and system configuration.
Programmatic Soluffons B-3 Rev 0 6/23/93 The Readiness Operation l
cal capacity check addressed the essentialissue of ensuring that the primary vertical ca- l pacity of nuclear plant raceway supports is at least equal to the capacity of earthquake ;
data base supports that performed well l The GIP analytical guidelines were derived from back-calculanons (see below) on i raceways that performed well in earthquakes that were larger (in many cases much larger) !
than the largest GL 87-02 SSE of 0.25g To simplify the generic guidelines however, SS- ;
RAP chose not to recommend that the wrtical capacity factor vary with the size of the GL 87-02 plant SSE. (llowever, when we initially developed the venical capacity guideline.
and presented it to SSRAP for their review, it did sary with the SSE size. Moreover, other GIP raceway analytical guidelines still do vary according to the size of the GL 87 02 plant SSE.) :
In the remaining paragraphs in this section, it helps clarify the discussion to have a quantitative)gure ofmerit of seismic margin The " seismic margmpgure of merit" (SMFOM) used here is the GIP raceway vertical capacity static load factor of 3 divided by the nuclear plant SSE ZPA. For example, at CR3 the SMFOM is 3/0.1 = 30. A SMFOM of 30 is not intended to imply that raceways that satisfy it have a seisrrs margin of 30.
The SMFOM is only intended to provide a way to assess the relative size of the seismic ,
margin at CR3 and other GL 87-02 plants.
Consider the case where the venical capacity factor of 3 is applied at the GL 87-02 l plant with the largest SSE ZPA of 0.25g. The leads to a SMFOM of 3/0.25 = 12. Since '
the SMFOM is 12 at the GL 87-02 plant with the largest SSE ZPA, this implies that the minimum raceway support SMFOM acceptable to NRC is 12.
Stated another way, the generic GIP raceway vertical capacity factor of 3 implies that the desired seismic margin at CR3 is 2.5 times the desired seismic margin at a Cali- <
fornia GL 87-02 plant 2 We are not aware of why the seismic margin at CR3 should be j larger than the margin at a California plant. Thus, the generic GIP vertical capacity race-way guideline appears to embody excessive conservatism for the low seismic conditions at CR3.
- We obtain one measure of excessiw :onservatism by calculating the CR3 vertical capacity static load factor that has the same SMFOM relative to its SSE as the California GL 87-02 plant SMFOM does to its SSE (which had a SMFOM of 12). This implies that i the plant specific vertical capacity static load factor at CR3 could be 1.2xDL instead of the generic value of 3xDL in the GIP.
At first glance, a factor as low as 1.2xDL might be viewed as unreasonably close to 1.0xDL (because it apparently does not account for canhquake loads). Such low fac-tors are not unreasonable. They arejust a natural consequence of a low seismic site. For example, if eanhquakes were impossible at a site, then it would not be unusual for 1.0xDL :
to be the criteria (that is, a dead load criteria only). However, to fully explain why will re-quire a discussion of the implications of the "back calculation" approach that we used to as the basis for the GIP screening guideline of 3xDL.
The key point is that back-calculations were performed on a large number of raceway supports that had experienced an earthquake and were not damaged. The back calculations were based on a set of assumptions, for example: (1) The static coeflicient 4
- 2. We realize that Rancho Seco is no longer a GL 87-02 plant. However, it was a GL 87-02 plant when the SQUG raceway guidelines were developed and a:cepted by NRC reviewers.
Programmatic Solutions B-4 Rev 0 6123/93 The Readiness Operation
approach, (2) Simple tributary area considerations, (3) Support eccentricities were ignored in calculating loads, (4) Specified allowable loads for welds, bolts (including expansion ,
bolts), and members, and (5) Limiting the back-calculations to consideration of the pri- !
mary vertical support connection or detail.
Because of novel consequences of the back-calculation approach, it can lead to re- i sults that are, at first glance, counter-intuitive. For example, the 3xDL factor was based on using a factor of safety of 4 for expansion anchors in the back-calculations. If the fac- l tor of safety used in the back-calculations is increased to twice this, or 8 instead of 4, then this would mean the GlP screening guideline would be adu_ggd to 1.5xDL instead of i 3xDL. This is illustrated in the following schematic illustrative back-calculation:
Capacity / Dead Load = 3 (using FS of 4.) i However, if the FS is changed to 8, then the inferred support capacity in the back-calcula-tion will be one-hsif that when a FS of 4 is used, but the dead load remains the same. The revised back-calculation is now as follows:
(Capacity /2)/ Dead Load = (Capacity / Dead Load)/2 = 3/2 = 1.5 (using FS of 8).
t in other words, when we use a FS of 8 the inferred capacity is 1.5xDL instead of :
3xDL. :
The point is that the absolute value of the factor (3 or 1.2 in the case being dis- l cussed here) is a consequence of the assumptions used in the back-calculations to develop it. There is no inherent reason why the factor derived from back calculations should be greater than 1.0, or why it should not be less than 1.0.
Of course, we are not saying that if the back-calculations indicate that the capacity factor should be less than 1.0, for example 0.6 (where it is obtained using the same rules and guidelines as in a dead load design or design check), that the cable tray supports ;
should not be designed for the full dead load of 1.0xDL. All we are discussing here are r the seismic guidelines. The dead load is treated in normal design using its own set of rules and guidelines, such as those in the GIP guidelines.
The conclusion of this section is that, considering the low seismic nature of CR3, {
and using the same technical approach as was used in developing the GIP guidelines, the j GIP 3xDL (seismic) static load factor at CR3 could be as low as 1.2xDL. ;
Original CR3 Raceway Seismic Criteria. The original CR3 raceway seismic l design criteria resulted in 15 different typical 2pports for cable trays and conduit. Each j of the 15 supports has an acceptable vertiera .oad and an acceptable unbalanced j (unsymmetric) verticalload defined for it for field guidance. Detailed structural dynamic analyses were used to develop the support details, the required structural capacities (for example, member types and sizes, size and length of weld, location and orientation of se-ismic bracing, and size and number of expansion and other bolts), and the acceptable ver- ;
tical and unbalanced venicalloads. (Structural dynamic analyses were also used to check l stresses in the cable trays and conduit for typical spans.)
Programmatie Solutions B-5 Rev 0 6/23/93 The Readiness Operation l
In addition, three-way restraint: were prosided at specified maximum honzontal distances, and at changes in direction of raceways The three-way restraints are often made up from closely spaced trapeze suppons, which are connected by 4x4x5/16 struc-tural steel angles welded to botb :rapeze suppons to form a three-dimensional space frame (which was dynamically analyzed to evaluate its structural adequacy) In other cases, three-way restraint is achieved by the addition of diagonal or other bracing.
A brief walkdown of the CR3 raceway supports revealed that they are of rugged construction it is obvious that they had been designed for eanhquake loads Most cable tray trapeze supports are fabricated from 4x4x5/16 (or larger) structural steel angles welded to form a planar frame. (For these supports, the three-way restraint is typi: ally constructed by connecting two closely spaced planar frames ) Most conduit suppons are fabricated from Unistrut members (Here the three-way testraint is typically constructed by adding bracing ) Some supports were noted to be supported from and welded to over-head stmetural steel, others are supported by bolting into Unistrut embeds, and still others are supponed by expansion anchors into the above reinforced concrete ficor.
The following analytical results were obtained by mrcrprenng the original calcula-tions that went into the development of the typical suppons. These results interpret the design loads and suppon capacities in temts of the GIP 3xDL Enaldcal venical capacity guideline for the purpose of comparison with it.
The ultimate venical load of Typical Trapeze Cable Tray Suppon 1 is supported by a welded connection to an overhead structural steel beam. Using the weld allowables in Table C.6-1 of the GIP, the welded support has a venical capacity of 48,720 lbs The cable tray dead load in this calculation is 1,800 lbs. For the purpose of comparison with the GlP guideline of 3xDL, the CR3 factor in this case is 48,720/1,800 = 27xDL, or much more than 3xDL. A number of other suppon types are based on this one, and they appear to have an even larger capacity relative to dead load.
The ultimate vertical load of Typical Trapeze Cable Tray Support 2 is supported by a bolted connection (2 3/4 inch bolts) to an overhead Unistrut embed. The bolted sup-port has a venical capacity of at least 12,800 lbs, using the plant-specific pullout allowable for 3/4 inch bolts. The cable tray dead load in this calculation is 1,800 lbs. For the pur-pose of comparison with the GIP guideline of 3xDL, the CR3 factor in this case is 12,800/1,800 = 7.1, or more than the GIP factor 3. The similar Typical Trapeze Cable Tray Support 3 has a CR3 factor of 14xDL.
The ultimate venical load of Typical Trapeze Conduit Support 4 is supponed by an expansion bolted connection (1/2 inch Phillips self drilling) to the overhead reinforced concrete floor. The bolts have a vertical pullout capacity of 4,580 lbs, using the dlowable in Table C.2-1 of the GIP. The largest conduit dead load in this calculation is 2,373 lbs.
For the purpose of comparison with the GIP guideline of 3xDL, the CR3 factor in this case is 4,580/2,373 = 1.9, or less than the GIP factor of 3, but more than the above-de-rived factor of 12. The 1.9 is the least factor we found.
The ultimate vertical load of Typical Trapeze Cable Tray Support 5 is supported ,
by a bolted connection (6 3/4 inch bolts) to an overhead Unistrut embed. The bohed sup- 1 pon has a venical capacity of at least 38,400 lbs, using the plant-specific pullout allowable i of 6,400 lbs for 3/4 inch bolts The tray dead load in this calculation is 2,340 lbs For the Programmatic Solutions B-6 Rev 0 6123/93,, The Readiness C9erstion
purpose of comparison with the GIP guideline of 3xDL, the CR3 factor in this case is 38,400/2,340 r 16, or much larger than the GIP factor of 3.
In conclusion, all of the above factors interpreted from the original CR7 raceway seismic design criteria are larger than the 1.2xDL derived in an earlier section, and many of them are much larger than the GIP guideline of 3xDL.
Seismic Re-Evaluation of CR3 Raceways In the 1982-3 time frame (years after CR3 was constructed and put into operation), the CR3 raceways were re-evaluated. A calculation package was developed for tach individual suppon and the specific loads on it, and a load control program instituted for each individual support. New suppons were designed in accordance with the criteria described in the following section.
CR3 Criteria for New Raceway Supports CR3 new raceway design criteria are similar to key GIP analytical screening guidelines.
CR3 Critenafor l'erticalLoads. CR3 criteria require cable tray supports to be designed for venical factors similar to those in the GIP.
The CR3 factors vary depending on the tray width. The fac; s for normal dead I
plus live loads varies from 1.6xDL to 2.4xDL. The values of 1.6 to 2.4 are obtained using the weights in Section 8.3.9 of the GIP and assuming the CR3 trays are fullt Thus, this provides a fair comparison with the GIP guideline of 3xDL in addition, CR3 criteria re- l J
quire the supports to be designed for a scismic venical load that varied from 0.1 to 0.5, depending on the building and elevation. The combined CR3 dead, live, and canhquake factor is 1.8xDL to 3.6xDL (1.8 = 1.6 x 1.1,3.6 = 2.4 x 1.5). Thus, the minimum CR3 design criteria factor of 18xDL is less than the GIP guideline of 3xDL, but it exceeds the minimum required CR3 plant specific GIP like criteria of 1.2xDL derived above. (Recall again that the minimum of 1.8 is achieved only for those suppons where d the trays are fully loaded. Typical values will be larger than 1.8.) In addition, the CR3 raceways are designed for lateral and 12ngitudinal earthquake loads, which is not required for the use of the GIP vertical capacity check of 3xDL, in other words, more earthquake loading con-siderations have been considered in the design and re-evaluation of the CR3 raceways than can be accounted for by the simple 3xDL GIP guideline, or was anticipated when we de-veloped the GIP guidelines.
CR3 Criteriafor LateralandLongitudinalLoads. CR3 criteria require a three-di-rectional restraint at the beginning, end, or along a tray run before a directional change.
Lateral restraints are also required every third support, or every 30 ft, whichever is less.
A brief walkdown of the CR3 raceways revealed that they are of obvious mgged construction. Numerous three-directional restraints were noted.
For some CR3 suppons, the GIP might require a check of their lateral load carry-ing capacity. One of the acceptable GIP screening lateralload screening guidelines is to analyze the suppon for the following loads:
" Dead loadplus a transverse acceleration of 2.5 times the Zero Period Acceleration (ZPA) of thefloor response spectrumfor the anchorpoint in the plant u here the raceum system is attached "
- 3. Note that this means the achieved factor at CR3 is more than 1.6 where the trays are not full.
Programmatic Solutions B-7 Rev 0 6123/93 The Readiness Operation
i E
As noted above, CR3 design criteria require many raceway supports to be de-signed for lateral loads The following table displays CR3 design criteria for those build-ings and elevations where 5% damped in-structure spectra are available. The results show that the lateralload used to design CR3 raceway suppons in these buildings and at these elevations varies from 4.2 to 7.1 times the floor ZPA (x DL). The table also shows that the verticaldead load used to design these CR3 supports varies from 2.0xDL to 2.4xDL.
Location CR3 Design CR3 Nsign Horizontal Accel- Vertical Dead eration/ZPA Load Factor Auxiliary Building, elev 143 7.1 2.3 Auxiliary Building, elev 162 5.8 2.4 Control Building, elev 145 4.2 2.0 Control Building, elev 163 5.2 22 Control Building, elev 186 6.5 2.3 !
The above table shows that all of these CR3 cases have lateral load capacities that I
are larger than the GIP guideline of 2.5 times the ZPA.
On the other hand, the CR3 design criteria require the horizontal and venical carthquake loading cases to be combined. This means that CR3 criteria require these sup- !
ports to be designed for a minimum of 4.2xZPA lateral load plus a simultaneous 2.0xDL ;
vertical load, while the GIP requires suppons to be checked for 2.5xZPA lateral load plus !
a simultaneous 1.0xDL venical load. Thus, the CR3 criteria for lateral (and longitudinal)
. load exceeds the GIP guideline in all cases. In addition, these CR3 raceways were de-signed from the beginning, and re-evaluated, using traditional sound eanhquake engineer-ing practice, that emphasizes lateral load resistance. ;
Thus, particularly for a low seismic site like CR3, where the SSE is only 0.lg, the t CR3 new raceway seismic design criteria and taceway construction suppon the judgment that these CR3 raceways meet the intent of the GIP and a case by case review of racev ays ;
at CR3 is not required to satisfy GL 87-02.
i Inclusion Rules. Finally, none of the Inclusica Rules in section 8.2.2 of the GIP, l are either applicable orjudged to be credible at a low seismic site like CR3. These are briefly discussed next.
i Rule 1 - Cable Tray Span. CR3 raceway criteria included a stress calculation on cable trays and the allowable loads on them. Later criteria used the same span limit as in l the GIP. j Rule 2 - Conduit Span. CR3 raceway criteria included a stress calculation of con- !
duit and the allowable loads on them.
Ru/c 3 - RacewayMember Tie-downs. Not required for trapeze suppons.
Rule 4 - ChannelNuts. CR3 uses Unistrut construction, which has acceptable >
channel nuts. t Rule 5 - RigidBoot Construction. None observed in walkdown. Even if there is ;
an occasional support with a rigid boot connection at CR3, the vast majority of the sup- l Programmatic Solutions B-8 Rev 0 6123/93 The Readiness Operation i
e o
pons at CR3 do not have rigid boot connections. Thus, the possible failure of an occa- l sional suppon is consistent with what is accepted by the GIP. In addition however, the i raceways at CR3 are restrained laterally and longitudinally, and CR3 is a low seismic site. .
Thus, even if there are any rigid boot connections at CR3, the raceways at CR3 cannot move laterally sufficiently to cause the failure mode that is of concern with the rigid boot )
connection.
Rule 6 - Beam Clamps. Not used at CR3 for safety-related raceways.
Rule 7 - Cast-Iron Anchor Embedment. Not applicable at CR3.
Other Seismic Performance Concerns. The Other Seismic Performance Con-cerns in Section 8.2.3 of the GIP are "less sigmpcant or less well-defined conditions I which should be evaluated during the plant walkdown....it is rot necessaryfor all of the raceway systems in the plant to be inspected in detailfor the Other Seismic Performance :
Concerns. Instead, the SRTshould note and evaluate any of these concerns, if and when they are noticed as apart of the walkdown. Ifit appears that any of the Other Seismic Performance Concerns are not met, then the SRTshould exercise their engmeering judgment in assessing whether the condition sigmficantly compromises the seismic ade-quacy of the raceuay system. " (Quoted from GIP Section 8.2.1)
None of the Other Seismic Performance Concerns were observed in a brief walk-down. In addition, neither of the two more significant ones (Concern 1 - Anchorage, and Concern 8 - HardSpots) are considered credible considering the careful seismic design and re-evaluation performed on CR3 raceways, I
Conclusion. Based on the good performance in past eanhquakes ofraceways not designed for earthquakes and constructed to normalindustrial practice, the fact that CR3 safety-related raceways were originally designed for and later re-evaluated for eanh- ;
quakes, and the fact that CR3 is a low seismic site, in ourjudgment the raceway systems l at CR3 meet the intent of the GIP. Thus, a case by case review of the raceway systems at !
CR3, to the screening guidelines in the GIP or to any other guidelines in addition to the raceway seismic criteria used at CR3, is not needed to satisfy GL 87-02. ,
Thisjudgment is supported by supplementary calculations interpreting the basis for the GIP vertical capacity guideline to infer a CR3-specific GIP-like guide!ine, and calcula- ;
tions interpreting the CR3 raceway design criteri:t in terms of GIP guidelines. .
t i
References for Appendix B !
B 1. The Performance ofRaceway Systems in Strong-Motion Earthquakes, prepared by ;
i EQE Engineering for EPRI on beha'f of SQUG, EPRI NP-7150-D, March 1991.
l t
Programmatic Solutions B-9 Rev 0 6123193 The Readiness Operation l l
8
Appendix C - Relays Introduction. It should be obsious that relay chatter is potentially much more of :
a problem in larger than in smaller eanhquakes. Conversely, relay chatter is potentially '
much less of a problem in smaller than in larger eanhquakes. This principal is recognized by NRC in that, in the seismic portion of the Indisidual Plant Examination (IPEEE--seis- ,
mic IPE) program, NRC accepts different criteria for evaluation of relay chatter in lower ;
versus higher seismic sites.
In siew of the previous paragraph, and the low seismicity at CR3, it follows that relay chatter is potentially much less of a problem at CR3 than at almost all other GL 87- ,
02 plants. As in the seismic IPE program, it is reasonable for CR3's GL 87-02 relay chat-ter approach to be reduced relative to other GL 87-02 plants. Thus, the issue is not u hether the CR3 approach to address GL 87-02 relay chatter issues can be reduced relative to other GL 87-02 plants, but by how much.
The relay chatter issue is recognized to be an operator issue. That is, the issue is i
not that a chattering relay is damaged or inoperable afte'r the eanhquake. Instead, chatter may cause an uncommanded change of state of relays, breakers, or other desices, and op-erators will have to reset them after the eanhquake. The issues are whether operators have sufficient knowledge to reset the devices that experienced an uncommanded change ;
of state during or after the canhquake, whether there are a sufficient number of operators, and whether they have sufficient time to reset.
The GL 87-02 relay chatter issue arose because of reports of operators in power ,
and industrial facilities in past earthquakes, that were collected through the data gathering effons of SQUG. When data are available, we believe that assessments of what could 1
happen in future eanhquakes are best guided by what happened in past earthquakes '
Thus, to develop the CR3 approach to GL 87-02 relay chatter issues, in the following we summarize data on how relays and operators have perfonned in past earthquakes.
Note that earthquake repons of relay chatter often contain an element of pessi- '
mism. This is because uncommanded changes of state in an eanhquake can arise from at a least three different root causes: (1) fluctuations in electrical quantities such as voltage or 2
current, (2) fluctuations in other quantities such as oil level or water pressure , and (3) 3 mechanical vibration of the relay.
In root cause (1), the fluctuations are caused by phenomena such as momentary shorts caused when transmission lines swing and touch, or damaged switchyard insulators. l Thus, for root causes (1) and (2), many of the relays function as designed when they ac-tuate. ,
In the repons below, the root cause of relay actuation is not always clear. How-ever, the available information is included for completeness. l The findings from an evaluation of the data summarized below are as follows. l l
l 1
- 1. Put another way, the purpose of this paragraph is to point out that we believe that ifit is fair to use carthquake data to identify concems, then it is also fair to use carthquake data to resolve them.
- 2. This is discussed in Finding 1.
Programmatic Solutions C-1 Rev 0 6123193 The Readiness Operation e
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l Finding I. With some exceptions, operators typically are able to quickly diagnose and correct relay actuations and restart plants This is true even though operators are acting in high stress post-eanhquake conditions, and they probably are not trained as thor-oughly as nuclear plant operators.
Finding 2. The eanhquake data do not indicate any relay actuations at the level of the CR3 SSE (0.lg). The lowest ZPA for which these data reveal a relay actuation is 0.14g (La Villita), and this was from a Buchholz type sudden pressure switch). !
Finding 3. The canhquake data suggest that very few relay actuations should be ]
expected for ZPAs equal to or less than the CR3 SSE ZPA of 0.lg. This can be seen from the following table4and chan.
Site ZPA No. of Ac-tuations Adak 0.25 1 Olive 0.3 2 Magnolia 5 0.3 2 Concon 0.3 1 Cool Water 0.28 3 (estimate)
El Centro 4 0.42 1 ElInfiernillo 0.15 1 Glendale 0.3 5 Humboldt 1&2 0.3 2 Humboldt 1 0.25 1 Ormond 0.2 4 Perry 0.18 5 ,
I San Isidro 0.6 3 (estimate)
Valley 4 0.4 2 These data plot as shown in the following chan.
- 3. However, when a Buchholz type sudden pressure switch actuates. it typically is only performing as l designed (usually sensing a pressure change - w hich often results from oil sloshing). The problem is that j' the system may falsely interpret the earthquake induced transient pressure as loss of oil-the real function the switch is intended to sense. This is a system design defect, which can be seen by noting that earth-quale inducedfalse actuation ofsudden pressure switches would not be prevented even ofthe switch is seismically quahfied.
- 4. Note that data from mercun switches and sudden pressure relavs has e been omitted from this table.
However, this does not change the conclusions. On the contrary, it results in a marginally pessimistic intr mtation of the data-see the probabilities below.
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Earthquake cata on Relay Actuations Nurnber of g O Relay 26- O Actuations 20<
At or '
Below the N'
g indicated O ZPA 5-e 0 0.1 0.2 0.3 OA 0.6 0.8 Zero Penod Acceleraten, g We fit a normal distribution to these data (the above data yield a mean of 0.3g, standard deviation of 0.12, coefficient ofvariation, CCV, of 0.12/0.3 = 0.4), and used a standard table of the normal distribution, t; interpret them statistically as follows: The probability of relay actuation for ZPAs at and below the CR3 SSE ZPA of 0.lg is about 4.7x10-2. This probability happens to decrease slightly when actuations of devices like mercury and sudden pressure switches are included.
We believe these data are skewed pessimistically. In other words, we believe the actual probability of relay actuation is less than 4.7x10-2. The reason is that the data are exclusively " failure " (actuation) data, rather than data that include success andfailure.
In addition, the data are based on a relatively large population of weak link cases over a relatively large population offacilitics andsites. We believe this means these data include more different kinds of root causes ofactuation than should be expected to exist at a ,
sing /c site such as CR3. This conclusion that these data are pessimistic is partially as-sessed in the following evaluation, which includes some effects of success data, i The following table provides an altemate estimate of the probability of relay ac-tuation (all data from Reference Cl). The important new data shown here are the total number of relays at sites. In other words, these data not only include relays that actuated, but also relays that did not actuate. The only sites we included in this table are those for which a basis exists for an estimate of the total number of relays at the site.
Plant ZPA No. of Ac- Total tuations No. of Relays Adak 0.25g 3 71* I Burbank 0.3 5 166*
Drop IV 0.3 0 46' El Centro 0.42 1 43*
Glendale 0.3 5 265**
Humboldt 0.25-0.3 7 38' Metcalf 0.4 4 189**
Ormond 0.2 5 128' .
Pasadena 0.2 0 127' Rinaldi 0.5-0.75 5 (estimate) 189*
Valley 0.4 4 228*
l Weighted average 0.35g Totals 39 1490 Programmatic Solutions C-3 Rev 0 6/23/93 The Readiness Operation ,
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- This estimate of the total number of relays at the site was obtained by counting relays. However, not all relays were counted. Thus, the estimate is known to be a strict lower bound to the actual total number of relays at the site.
" This is a realistic estimate of the total number of relays at the site, aiso obtained by counting relays. It may be a lower bound, but this is not known with certainty. This is because the number of relays was obtained both by count-ing and by estimation.
The estimate from the data in the above table is that, at a ZPA of 0.35g, the prob-ability of relay actuation is 2.6x10-2 (2.6x10-2 = 39/1490). Since 2.6x10-2 si less than 4.7x10-2, this tends to confirm that the previous estimate is pessimistic. This point is rein- '
forced considering that the total number of relays on which the 2.6x10-2 is based is a lower bound estimate. For example, the total number of relays is pessimistically estimated as 5,000 (Reference Cl) rather than 1490. Thus, at a ZPA of 0.35g, the probability falls from 4.7x10-2 to 7.8x10-3 (7.8x10-3 = 39/5000), or one-third as much.
The probability of 7.8x10-3 is associated with a ZPA of 0.35g (which is 3.5 times !
the ZPA of the CR3 SSE) and earthquakes oflonger duration than are expected at CR3.
Considering these and other pessimisms discussed above, for engineering purposes we estimate that, for earthquakes with ZPAs equal to and less than the CR3 SSE of 0.lg, the probability of relay actuation is at most 1x10-2 (or somewhat more than 7.8x10-3).
Note that these results did not take credit for the 6,968 relays and up to 5 actua- j tions at the Perry plant. If these data are included in the above table, then we have 44 ac-tuations in 11,968 relays. This leads to a probability of 3.6x10-3, or half the 7.8x10-3 developed above. We did not include these data because the Perry plant is new and all of its safety-related relays are qualified. Thus, their inclusion could be viewed as unfairly skewing the results relative to what should be expected at CR3.
The probability of lx10-2 means that even if there are as many as 5005 essential re-lays in the CR3 SSEL, and we assume that none of them are quahfied, then we expect less than 500 x (1x10-2) = 5 of them to actuate in the unlikely event of a CR3 SSE. This is a conditional estimate, where the condition is the occurrence of the CR3 SSE. The condi-tional estimate where the condition is an earthquake rather than the CR3 SSE is obtained as follows.
Combining the above probability of actuation with the probability of an earthquake at CR3, we find there is a probability of about 10-6 of relay actuation in the unlikely event of an canhquake (not specifically an SSE) at CR36 . This estimate means that even if there are as many as 500 essential relays in the CR3 SSEL, then we should expect less
- 5. Based on the number of essential relays at other A46 plants. we believe this estimate is an accurate one.
However, we are continuing to further clanfy the bases for our estimate of 500 essential relays. If we conclude that a better estimate is substantialh different that 500, FPC will adsise NRC of this.
- 6. The probability of 10 is 4 obtained from the median curve in Figure 5-1 of Reference C4 at the mean ZPA of 0.35g. This rule of thumb closely approximates the exact calculation. which integrates two prob-ability distributions: (1) the carthquake hazard probability distnbution from Figure 5-1, and (2) probabil-ity distribution of actuation given an earthquake.
Programmatic Solutions C-4 Rev 0 6123/93 The Readiness Operation
than one to actuate in the unlikelv event of an eanhquake (not necessarily an SSE) at CR3.
Of course, there is the issue of whether these data and estimates are representative of the plant specific and site specific conditions at CR3. Until such time as there are more _,
credible performance data on large populations of relays exposed to realistic plant opera-tional, installation, and canhquake conditions, such as those discussed above and below, ,
we continue to believe that these data are more credible, and are a better indication of f what we have reasonable assurance to expect, than estimates that are based on seismic analyses that are typically pessimistic. ;
Finding 4. There is reasonable assurance that there is a large margin against relay )
I chatter relative to the CR3 SSE of 0 Ig. This is explained as follows.
from Finding 3, the COV of the actuation data is OA Taken together, the prob-ability of 10-2 from Finding 3 and the COV of 0.4 imply that the mean failure level is :
about 1.0g. This implies the margin relative to the CR3 SSE ZPA of 0 lg is about 10. :
As discussed above, the raw data have a mean of 0.35g. These data are known to I have a pessimistic bias, which implies the margin is a minimum of 3.5 relative to the CR3 SSE ZPA of 0.lg. Thus, that the minimum margin is 3.5 does not suggest that the margin .j estimate of 10 is optimistic. t Large margins are credible in view ofhow small CR3's SSE is. In other words, ,
large margins are a normal consequence of the low seismicity ofpeninstdar Florida.
Finding 5. Because the CR3 SSE is so low (the CR3 ZPA is only 0.lg), carth-quake data suggest there is a high probability that switchyard damage will not occur in the event of the CR3 SSE. This means there is a much higher probability that CR3 will not lose offsite power in a CR3 SSE, than at many other GL 87-02 plants. Thus, CR3 operators will probably not have to deal with restoring power to vital equipment after an canhquake. This suggests CR3 operators will be more likely to be able to reset relays ;
than operators at most A46 plants, which have larger SSE tbm CR3. <
Conclusion. Considering these Findings: (1)If the CR3 SSE causes any relay actuations at CR3,it probably will cause only a few. Moreover, the low CR3 SSE prob- .
ably will not cause loss of offsite power. (2) CR3 operators probably will not have to deal with post-SSE issues of restoring power to vital equipment. (3) Taken together, these two conclusions mean there is reasonable assurance that CR3 plant operators will quickly i diagnose and reset any relay actuations-cenainly better than at most A46 plants (which have much Iatget SSEs than CR3's). (4) Thus, according to thefirst specific assumption'
(
in Section 6.3.1 ofthe GIP, CR3 meets the GIP. anda case-by-case relay evaluation program is not required at CR3 to address GL 87-02.
- 1. Which is as follous: "Unquahfied relays are assumed to malfunctn,n dunng the short penod ofstrong i motion during an earthquake. Such a malfunction. Opically chatter, may result m loss ofsystemfunction i or inadvertent actuation ofsystems dunng the strong shaking period It is also possible that relay mal-function during strong shakmg can result in unacceptable seal-in or lockout ofspecific circuits u hich are designed to have thisfeature. In such cases, operator actions to reset or restore such circuits to their origmal condition may be acceptable provided there are sufficient tin:t. awareness, access andproce-duresfor the operators to tale this action " CR3 satisfies this because, (1) there will be few post-SSE demands on CR3 operators and (2) u e don't consider " strong motion ' or " strong shakmg." to be very realistic desenptions of minor, almost inconsequennal, earthquakes like the CR3 SSE of only 0.lg.
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l Earthquake Data. The remainder of this Appendix presents available eanhquake induced relay actuation and operator action data upon which the above Findings and Conclusion are based. The data are only gathered and presented below for the conven-ience of the reader, who may not have the reference material readily at hand. The evalu-ation of the following data is presented above.
General Data. The following general canhquake data is included for the conven-ience of the reader.
"The data base contains no evidence of seismically induced malfunctions ofhort-
- ontalpumps (inadvertent starting or stopping). " (Reference C2, page 5-8)
"The data base contains no evidence of the malfamction ofmotor-operated valves durmg an earthquake. " (Reference C2, page 8-5)
"The data base contains no evidence ofseismically induced malfunctions (inadvertent starting or stopping) offans. " (Reference C2, page 9-9)
"The data base contains no evidence ofseismically induced malfunctions (madvertent starting or stopping) of air handlers. " (Reference C2, page 10-6)
"The data base contains no evidence ofseismic malfunctions (madvertent starting .i or stopping) ofchillers. " (Reference C2, page 11-5) j "The data base contains no evidence ofseismic malfunction (inadvertent starting or stopping) (of air conpressors] during an earthquake. " (Reference C2, page 12-6)
"The data base contains no evidence of the seismic malfunction (inadvertent starung or stopping) ofmotor-generator sets. " (Reference C2, page 13-4)
Specific Data. In the following, available data on eanhquake induced relay actua-tions are summarized. The data are primarily from two SQUG publications (References C1 and C2). In each case, the source of the data is indicated. For some sites, for exam-pie, Adak Naval Station, data from both SQUG publications are included for complete-ness. This leads to some redundancy, but the flavor of both publications is retained.
Adak Naval Station. At the Adak Naval Station, which experienced an estimated peak ground acceleration of 0.25g during the magnitude 7.51986 Alaska eanhquake, the Birchwood Substation tripped due to actuation of a General Electric IBCG protective re-lay on a 13.8 kV switchgear. Once the relay was reset, the substation went back on line, and normal operation resumed. (Reference C2, page 3-8)
The Birchwood Substation is a small electrical substation on Adak Island. A GE IBCG phase directional ground relay tripped the No. I breaker in the 13.8 kV switchgear at the substation. The operator's log indicated the trip was caused by canhquake induced vibrations. The breaker provides the tie betweer> the NAVFAC substation and Birch-wood. The power line runs underground. Thas, slapping together of power lines was dis-counted as the source of relay actuation. Shortly after the canhquake (the exact time was not documented) the tripped breaker was identified, the operator reset the relay at the 13.8 kV switchgear and normal operation resumed. (Reference Cl, page 4-13)
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i At Steam Plant Number 3 on Adak Naval Station, which experienced an estimated ZPA of 0 25g during the 1986 Alaska canhquake, two pressure switches were tripped.
During the earthquake, vibration of the internal push rod caused the actuation of dia- ;
phragm-type sudden pressure switches on two of the boilers. These switches are on a
" hair-trigger" and are easily actuated by vibrations. The actuation of the switches tripped l an auxiliary relay, which, in turn, tripped the motor control center controlling the boiler !
> fan motor. There was no damage to any of the equipment in this system. (Reference C2, !
page 18-6) ;
Steam Plant 3 on Adak Island was operating at the time of the canhquake and had several earthquake induced actuations, none of which were identified as having been caused by relays. Two sudden pressure switches on the boilers tripped and had to be reset manually before the boilers could be relit. A boiler fan motor also tripped ofrwhich was initially believed to be caused by the canhquake induced vibrations of a fan motor contac-tor. After further discussions with plant personnel, it was determined that this is an auto-matic function when a boiler fire trips (Reference Cl, page 4-13) ,
Burbank Power Plant. At the Burbank Power Plant, which experienced an esti-mated ZPA of 0.3g during the magnitude 6,51971 San Fernando, California earthquake, !
two tripped protective relays in the generator control panel caused the gas turbine genera-tor to fail to start on demand following the earthquake. (Reference C2, page 17-7)
The Burbank Power Plant consists of the tivo Olive units and the five hiagnolia un'!s.
Olive Units 1 and 2 were on line at the time of the canhquake at 6:01 a.m., and l were tripped offline by spurious relay actuation. The relays were identified as GE Type CFD, which are located on the main control panel on the second floor of the Control Building. The CFD relays activate a multi-contact auxiliary relay, which trips the genera- ;
tor offline, trips the house transformer OCB, transfers power to the station auxiliaries !
from the start-up transformer, and trips the turbine stop valve. l Station power was being provided from offsite sources at the time of the earth- !
quake. At about 6:15 a.m , offsite power was lost to the Olive units due to damage i throughout the Southern California power grid. A 6:37 a.m., offsite station power was j made available from Recovery Station E. The furnace purge was completed on both units i at 7:00 a.m., and the boilers relit. Unit I was brought back on line at 8:09 a.m. and Unit 2 !
at 8:24 a.m. No other relay malfunctions were identified at either Olive unit. (Reference C1, page 4-5) hiagnolia Units 2 and 3 were on line at the time of the earthquake. Both Units 2 and 3 remained on line during and following the earthquake. However, reduced fuel oil pressure due to a pipe leak, and loss of steam pressure convinced the operator to manually trip both units. The auxiliary generator at hiagnolia Units I and 2 started up. However, the plant draft fans and the feed pumps are too large to be supplied by the auxiliary gen-erator, so the operator had to kill the fires and trip the turbine. j A startup of hiagnolia Unit 5 (a gas turbine peaking plant) was attempted, but both the turbine and the generator were locked out by relay actuation and the operators could not immediately determine which relays needed to be reset. Three spurious relay actua-tions were found to have occurred at Unit 5 and caused the blocked start: (1) hiain trans-Programmatie Solutions C-7 Rev 0 6/23/93 The Readiness Operation
l former sudden pressure, (2) Low voltage relay on the sequencer power supply, and (3)
Loss of field. '
The main transformer sudden pressure relay is a Westinghouse Type SPR. The low voltage ielay on the generator sequencer power supply is a GE Type IAV. The loss of field relay is a GE Type CEH. By 6:47 a m. operators had found the actuated relays and Unit 5 was on line. No other relay malfunctions were recorded at the Magnolia units. ;
(Reference Cl, pages 4-5 and 4-6) :
City of Commerce Plant. At the City of Commerce Refuse-to-Energy Plant, which experienced an estimated ZPA of 0 4g (tecorded I km west of plant) during the l 1987 magnitude 5.9 Whittier, Califomia canhquake, the plant operated through the main shock of October 1 without tripping oft-line. The plant manager reponed that the motion in the cont ol room three floors above gnde was brief but intense items slid from shelves and a ventilation diffuser dislodged from the ceiling. A small waterline attached to the potable water heater ruptured, apparently due to rocking of the heater tank. There was no damage to any of the primary electronic or mechanical systems in the plant. All control and instrumentation systems appeared to work properly. (Reference C7, page B-8) l Concon Refinery. At the Concon Oil Refinery, which experienced an estimated ZPA of 0.3g during the magnitude 7.81985 Chile earthquake, the emergency diesel gen- >
erator started during the carthquake, but tripped off-line due to protective relay actuation.
The relay was reset and the diesel operated properly. (Reference C2, page 17-8)
The refinery was operating at about 80 percent of capacity when the earthquake occurred. Power from the mail grid was lost during the earthquake. The on-site steam turbines (which provide power to the control rooms) functioned properly. The emergency diesel generator started automatically during the canhquake, but tripped offline almost immediately during the start sequence due to actuation of a GE Type IAC fault current protective relay. The panel containing the relay was stifTened with structural steel angles.
The operator felt that contact chatter in the relay caused the trip. The generator was ,
manually started a few minutes later and operated nomially. There were no other misop-erations, malfunctions, or false alarms reported with any other system. (Reference Cl, page 4-15)
Cool Water Station. The Cool Water Station experienced a magnitude 7.5 earth-quake, and a ZPA of 0.43g was recorded at the site. At the time of the initial event, one -
gas turbine of Unit 3 was on line and the Unit 3 steam turbine was in the process of being brought on line. All other turbine generators were down. The gas turbine tripped offline and shutdown due to its vibration trip system. Most circuit breakers in the 115 kV and 230 kV switchyard opened due to relay actuation on the control panels. The operators j believed the relays actuated on vibration. ,
El Centro Steam Plant. At the El Centro Steam Plant, which experienced an ZPA of 0.42g during the magnitude 6.61979 Imperial Valley, California eanhquake, Units '
I and 2 were shut down at the time of the canhquake, while Units 3 and 4 were operating.
Both Units 3 and 4 were tripped offline by damage to a lightning arrestor on the 1-Tl Programmatic Solutions C-8 Rev 0 6123/93 The Readiness Operation
transformer. This is an automatic function as the 1-Tl transformer provides station serv-ice power to Units 3 and 4. Unit 3 was brought back on line 15 minutes after the earth-quake. Unit 4 required repairs to the generator exciter cooling water lines and was ,
brought back on line 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> after the canhquake.
Unit 3 was tripped offline but continued generating its own station power, while Unit 4 went completely black. The Unit 4 generator was believed to have been tripped by l its differential relay due to spurious relay actuation. After the earthquake, Unit 4 picked ,
up its indoor 480V bus from Unit 3, which restored station power to Unit 4 and allowed its auxiliary systems to become operational. Unit 3 was synchronized back onto the power grid 15 minutes after the earthquake, but only operated at 10 MW because the Unit 3 cooling tower fans were locked out. The fans are energized from the outdoor 480V bus.
- The outdoor 480V had two breakers that would not operate, which prevented the bus from being energized from its respective 2.4 kV bus or 480V tie bus. The 3-10 and 3-OSP breakers failed to operate. Both the El Centro operators and the breaker repair technician who serviced the breakers after the earthquake attributed their operational fail-ure to the sensitivity of this type of breaker (GE AK-1-50) to moisture and dirt build-up, These breakers require frequent cycling to assure "on demand" operation. The breakers were placed in their test position, cycled, and placed into service 35 minutes later. The site visit verified that the breakers are mounted in an outdoor enclosure located adjacent to the Unit 3 cooling tower structure. The internal of the cabinets were found to be dusty, and moisture was falling from the cooling tower. (Reference Cl, page 4-12)
El Infiernillo Power Station. At the El Infiernillo Power Station, which experi-enced a ZPA of about 0.15g during the magnitude 8.1 1985 Mexico earthquake, three of ,
the five units were in operation during the earthquake. Two units disconnected from the power grid by the actuation of a high voltage circuit breakerin the station switchyard.
They were tripped by faults in the transmission network in Mexico City. Thus, their relays performed their intended function. The third operating unit disconnected from the power grid due to actuation of a ground fault relay. Plant operators believe that this relay tripped due to earthquake induced vibrations on the relay, which then sent a spurious signal to the breaker. All three units were placed back into service once undamaged distribution paths were established in Mexico City, and the ground fault relay checked and reset. (Reference Cl, page 4-17)
Gilroy Cogen Plant. At the Gilroy Energy Cogeneration Plant, which experi-enced an estimated ZPA of 0.3g during the magnitude 7.1 1989 Loma Prieta, California earthquake, both the gas and steam turbine generators were in operation at the time of the ;
earthquake, feeding power into the local 115 kV grid. Protective relays detected an over- ,
current condition in the 115 kV grid and tripped both turbine generators off-line. As the shaldng continued, the local i15 kV grid blacked out, shutting off power to the Gilroy area. Loss of normal off site ac power shut down all mechanical equipment, and triggered ,
shutdown of the gas and steam turbines. Backup power for critical circuits such as the programmable control system continued through the uninterruptible power supply.
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Off site power became available about 20 minutes after the eanhquake. Operators inspected the plant and, finding no damage, restarted the gas turbine about an hour after the earthquake.
l However, problems presented restart of the steam turbine Water had seeped into l the main steam line. The water source may have been earthquake-induced sloshing in the main steam drum high in the plant. Moisture reaching the hot turbine through the steam line caused minor thermal distonion in the rotor, which, in turn, caused excessive vibration as the turbine was brought up to speed. A second attempted restan also had excessive !
vibration When a third restart was attempted around 11:30 pm, the turbine vibration was !
acceptable. The steam turbine was brought on line around midnight, about seven hours after the earthquake. A thorough inspection of the plant revealed no significant damage to ;
either stmetures or equipment. The plant was kept on-line at fullload for several days af-ter the earthquake--prosiding much need power for the grid. (Reference C7, page B-19)
I Glendale Power Plant. At the Glendale Power Plant, which experienced an esti-mated ZPA of 0.3g during the magnitude 6.51971 San Fernando, California earthquake, Units 3,4, and 5 were in operation at the time of the earthquake, and stayed on line during i and following it. One and one-half hours after the earthquake, all three units tripped os !
line because of system disturbances throughout the entire Los Angeles area. Units 3 and 4 were brought back on line two minutes later, and Unit 5 was brought up nine minutes later.
I
- The operator's log documents the following relay induced trips (none of which af-fected the normal operation of Units 3,4, and 5)
- (1) Number 1 differential, (2) Glendale- !
Rossmoyne 34.5 kV lines, (3) Glendale-Grandview 34.5 kV lines, (4) Glendale-Grandsiew i South (relayed at substation), (5) Glendale-Acacia East and West (relayed at substation), .
1 Glendale-Fremont Nonh and South (relayed at substation). All of these relays were GE
- Type CPD. These are pilot-wire differential type relays, which are used for the inter-i change of relaying information in the form of currents or voltages between the relays at !
4 the two line terminals. The relays have a current balance characteristic arranged to cause relay operation if the current entering the protected line section is not balanced by the cur- l rent leaving it. Under external fault or normal load conditions these currents are in bal- l 4
ance, and the relays will not trip. For internal faults however, the currents will not be in ;
balance and the relays will trip the breakers at the line terminals. !
The operators could not determine whether the CPD relays performed their in- l tended function (for example, actuated by internal faults in the lines due to power lines i i touching), or whether the vibration of the relay contacts caused the trip. Plant operators }
)
speculated that the relay caused a spurious signal based on their experiences in causing l trips with these relays when accidentally bumping or drilling holes in their cabinets. !
(Reference Cl, pages 4-6 and 4-7)
Humboldt Bay Power Plant. At the Ilumboldt Bay Power Plant, which experi-j enced an estimated ZPA of 0.3g during the magnitude 5.51975 Ferndale, California
, canhquake, actuation of a mercoid switch caused the motor-operated gas supply valve to j Unit I to close, resulting in the tripping of the Unit I boiler. (Reference C2, page 18-5) :
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l Units 1 and 2 were on line at the time of the canhquake while Unit 3 was down for scheduled maintenance Both Units I and 2 had their generator oil circuit breakers (OCBs) and auxiliary transformer OCBs trip due to spurious relay actuation. Auxiliary electrical equipment associated with these units transferred to the plant stanup banki which remained energized from the plant's 60 kV bus. The plant operator's log states; i
" spurious auxiliary relay action caused a loss of field on both units." The loss of field re-lay is a Westinghouse type IILF relay. It is located on the master control board together with its MG-6 auxiliary relay. In addition, a mercoid switch spuriously actuated causing ;
the closure of a motor-operated gas supply valve to Unit 1, which tripped a forced draf) ,
fan on the Unit I boiler.
At the Unit 3 nuclear unit, spurious relay action was reponed on one of a pair of [
redundant GE type 11EA relays in the refueling building related to the liigh DifTerential l Pressure Protection System. The IIEA relays are auxiliary relays for two mercoid type PQ l protective pressure switches, which are connected in series and sense pressure changes in -1 the liigh Differential Pressure Protection System The mercoid switches spuriously actu-ated and tripped the llEA relay, which closed the primary system isolation valves associ- ;
ated with the emergency condenser and the reactor cleanup systems, and tripped the reac- !
tor cleanup pump. The switches were replaced in 1977. To ensure that the llEA auxiliary i relays had not caused the isolation valve closure in the reactor clean-up pump trip, lium- !
boldt engineers tested and seismically qualified the IIEA relays. (Reference Cl, pages 4-10 and 4-11) l The 11umboldt Bay Power Plant experienced an estimated ZPA of 0.25g during the l magnitude 7.01980 Eureka, California eanhquake. Units 1 and 2 were on liac at the time :
of the canhquake, while Unit 3 had been out of service since 1976. Unit I was tripped off f line by a GE type CFD high speed differential relay. Operators felt that the CFD gave a i false indication of electrical trouble within the generator. Unit 2 sustained a transient cut- :
off of fuel due to shaking of the gas regulating stop valve mercoid switch At the same l time, the internal mechanism of the air flow meter dislocated; therefore, Unit 2 was tripped ;
by the operator. Unit 2 was restaned about 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> afler shutdown. Unit I generator was l checked and the unit was restarted, about 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> after shutdown. Unit 3 was inspected !
by plant stafrafter the earthquake and they found no damage. (Reference Cl, pages 4-11 l and A-35) .
Krsko Nuclear Plant. The Krsko Nuclear Power Plant is located 2 km east of the i town of Krsko on the northern bank of the Sava River in the Republic of Slovenia. On December 28,1989, the Krsko Plant experienced a magnitude 3.9 earthquake and re- !
corded a free field motion with a ZPA of 0.56g. l Plant operators heard an audible sound caused by the canhquake that sounded like ;
a passing freight train. They also noticed annunciation of an earthquake on the control panel. !
They interpreted the audible earthquake sound as a rupture of non-safety class 3 piping systems, and manually tripped the plant. Plant personnel performed detailed walk- !
downs of the plant and found nothing unusual except the spurious high water level indica- l tion at the non-safety class level switches (Deha model 760/770) of the feed water high !
pressure reheaters. After the reset of the level switches, the plant went back on line and l i
t Programmatic Solutions C 11 Rev 0 6123/93 The Readiness Operation I
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onerated smoothly. Operators concluded that the plant would have tripped automatically to protect the turbine generator by the spurious level switch signal, if the plant operator had not tripped the plant manually.
A magnitude 31 aftershock earthquake occurred several days later. It tripped the ,
plant automatically on an indication of steam generator high water level. Plant personnel ;
3 again performed detailed plant walkdowns. They found nothing unusual except that the !
non-safety class low pressure feed water reheater had a spmious level switch indication of ;
high water level, which caused the high water level indication in the steam generator. Af- ,
ter operators reset the level switches, the plant went back on line and operated smoothly.
(Reference C3) ,
La Villita Power Plant. At the La Villita Power Plant, which experienced a ZPA of 0.14g during the magnitude 8.1 1985 Mexico eanhquake, two of the four units were in ,
operation during the eanhquake. Both units disconnected from the power grid in the earthquake due to actuation of protective relays. This was attributed to Buchholz type sudden pressure relay actuations caused by oil sloshing in the switchyard transformers.
The plant disconnect was also attributed to grounded transmission lines at the steel plant :
in Lazaro Cardenas. The two units were reconnected with the power grid after a briefin-spection. (Aeference C1, page 4-17) i Metcalf Substation. At the Metcalf Substation, which experienced an estimated ;
ZPA of 0.4g during the magnitude 6.2 Morgan Hill, California eanhquake, four relay ac-tuations were reported. No other details are available. ,
New Zealand Distillery. At the New Zealand Distillery, which experienced an estimated ZPA of 0.5g during the magnitude 6.21987 New Zealand earthquake, a level l controller was found to be non-functional following the eanhquake. The controller ;
4 monitors the level of the distillation column through a diaphragm-actuated differential l 5
pressure sensor. The controller is calibrated to operate at a range of 3 to 15 psi. Appar- ,
ently, sloshing of the fluid in the distillation column during the earthquake caused a pres-sure surge, which, in turn, tripped the pneumatic overload relay within the controller.
- Once the relay was manually reset, the controller was operational. (Reference C2, page 18-6) I
- Ormond Beach Generating Station. At the Ormond Beach Generating Station, !
3 which experienced an estimated ZPA of about 0.2g during the magnitude 5.71973 Point !
J Mugu, California eanhquake, Unit I was operating at the time of the earthquake and was !
tripped offline. The A phase generator differential relay and the A, B, and C phase volt- ,
, age unbalance relays produced targets. Plant operators felt that the canhquake induced j i vibrations caused the plant to trip. They supponed their view by showing that the relay i panel was very flexible and that an operator shaking the panel caused the relays to actuate. l l The panel was structurally stiffened after the canhquake to prevent this low frequency vi-bration in the future.
The generator differential relays are located on the main panels in the relay and in-strumentation room, whose elevation is between the ground and turbine levels. They are Programmatic Solutions C-12 Rev 0 6/23/93 Tbe Readiness Operation l
GE Type CFD, and are located at the top of the relay panel. They are attached using the standard four bolts to the panel face. The generator voltage unbalance relays are GE Type !
CFVB, also mounted near the top of the relay paneljust below the CFD relays with the j standard four bolts. l The log book indicates that several other control room relays targeted. These, along with operator interpretation of their causes are: (1) Generator trip - annunciator ,
showing that the generator had tripped, (2) Low feedwater flow - due to the boiler trip, ,
(3) Low oil pressure - probably a mercoid switch, (4) Thrust bearing - probably a mercoid ;
switch, and (5) Turbine overspeed - normal when the turbine trips. The operators could ,
not determine whether these target actuations were vibration induced or if they were re-sponding as designed to another physical condition. (Reference Cl, page 4-8 and 4-9) {
i Pacific Lumber Plant. At the Pacific Lumber Cogenerztion Plant, which experi-enced an estimated ZPA over 0 4g in the magnitude 6.9 April 25,1992 Petroilia, Califor- l nia earthquake, Unit A turbine generator was on line near full power at the time of the in- _j itial earthquake at 11:06 am. Turbine generator B was down for maintenance. l Actuation of a generator overload relay in the control room tripped Unit A offline and initiated shutdown of the boilers. In spite of the intense level of shaking, the off site ;
supply of 60 kV power was maintained into the cogen plant. The source of 13.8 kV sta- l tion power sutomatically transferred from Turbine Generator A to the substation's ;
60/13.8 kV transformer. This maintained power within the cogen plant to all operating equipment. l Operators inspected the plant after the earthquake. The most serious damage
. found was in the emission control system. Sway and impact of the charged plates within 1 the electrostatic precipitators created electrical faults and disconnections. Only a portion }
of the electric field in one out of three precipitators was found to be operable. This was !
sufficient to allow a reduced level of steam generation for a limited time. l After an inspection, Boiler A was refired, and Turbine Generator A was brought ;
back on line. Operators began the process of refiring Boiler B to increase steam genera- !
tion, and power, from Generator A. The startup process requires the use of oil to fire the ;
boiler until sufficient heat is achieved to combust wood waste efliciently. l The cogen plant appeared to be on the way back to normal operation, albeit at re- [
duced capacity, when the second, magnitude 6.2, earthquake struck on April 26 at 12:41 :
am. l The second earthquake also tripped Turbine Generator A offline. Station sersice power was lost, so that all AC-powered mechanical equipment deenergized. The control i
4 system continued to function on power supplied from its unintermptible power supply system. The battery rack and the UPS supplied the digital controls system, emergency lights, control power for all switchgear, and the DC lube oil pumps that allowed coast down of the turbine generator. l Shonly after the second earthquake, a check ofinstrumentation revealed that the 1 60 kV supply to the plant substation was still energized from the off site grid. The loss of i station power turned out to be due to actuations of 13.8 kV circuit breakers within the plant, rather than blackout of the local grid. Once again, the 60 kV supply to the plant had been retained in spite of very strong ground shaking (an estimated ZPA of 0.4g).
Programmatic Solutions C-13 Rev 0 6/23/93 The Readiness Operation
Within about 10 minutes, the 13.8 kV breaker was reclosed to the plant substation and station service power was restored. The control system readout revealed that Turbine Generator A had tripped on a thmst bearing alarm. It appeared that the generator rotor had contacted and perhaps damaged the bearings during the shaking Some time later when the turbine generator was rolled on the turning gear, the resulting "squan k" indi-cated that a restart should not be attempted Investigations revealed that the generator casing had shifted about 1/8 inch on the concrete floor. Similar shifting was also noted on Generator B. Since it was apparent that the unit should not be restaned, operators de-cided to disassemble Generator A for the same overhaul that Unit B was undergoing.
When the third, magnitude 6.5, earthquake struck at 4:18 am on April 26 (with an estimated ZPA of over 0.2g), the cogen plant was already offline and no specific effects were noted. Power from the off dite grid was retained and there were no apparent mal-function in the control or power supply systems in the plant.
Both mechanical and electrical power supply systems within the cogen plant sur-vived the eanhquakes with minimal effects. Tanks and heat exchangers escaped damage.
No problems were encountered in mechanical equipment such as fans, pumps, or control valves in the process of restaning the plant. Pneumatic tubing in the plant instrument and service air systeus remained intact, except at severallocations where sway of the boilers buckled pressure taps (Reference C7, page B-35)
Perry Nuclear Plant. The Perry Nuclear Plant is about 56 km nonheast of Cleveland, Ohio on the shore of Lake Erie. On January 31,1986, a magnitude 5.0 eanh-quake occurred near Leroy, Ohio. The epicenter is estimated to be 17 km to the south of the Perry Plant, which recorded a ZPA of 0.18g. At the time of the earthquake, the Perry Plant was under pre-operational testing prior to fuel load.
There were 47,000 electrical components in 70 separate safety and non-safety systems that were energized during the earthquake. None of them experienced adverse affects like spurious starts or alarms. The 345 kV breakers in the switchyard were tripped as designed after the chattering of the turbine generator loss of excitation protective relay.
This is an induction cylinder type relay. The chattering was caused by the lack of AC re- '
straint voltage on the cylinder, which was caused because the isophase bus potential trans- ,
former was racked out. A total of five non-safety related relays actuated, of which three !
were in the more sensitive de-energized state. (Reference C3) l Out of a total of 6,968 identified relays, at least one (and possibly up to three) de- l energized non safety-related protective relays closed contacts due to motion during the j earthquake. All safety-related relays continued to operate normally through the earth- j quake. (Reference C5) ;
The East Lake fossil plant is 20 km to the west of the epicenter area. The unit 5 l turbine generator was tripped by the vibration monitor-in other words, it performed as l designed when it sensed vibrations from the earthquake. (Reference C3) !
The Painesville Municipal Power Plant is about 17 km northwest of the epicenter.
At least six boiler alarms (triggered by mercoid switches) caused the operator to manually trip the only operating unit (#5) as a precautionary measure. The tripped boiler was re- ,
staned about one-half hour after the eanhquake after an inspection revealed no problems. i (Reference C6) l Programmatic Solutions C-14 Rev 0 6!23l93 The Readiness Operation l
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l No relay actuations at the following power plants: Ashtabula--about 33 km nonh- l west of the epicenter, Lake Shore--about 29 km southwest of the epicenter, and Avon- !
about 70 km southwest of the epicenter. (Reference C6)
Puente Ilills Station. At the Puente Hills Landfill Gas-to-Energy Station, which experienced an estimated ZPA of 0.4g in the magnitude 5.91987 Whittier, California ,
canhquake, the plant was in operation at the time of the main shock of October 1. The operator observed the swaying of the turbine-generator structure through the control room window, which caused the operator to manually shut the plant down over concern l about possible structural damage. An inspection of the plant revealed no damage.
Off site power from the nearby Mesa Substation was not lost in the earthquake. !
However, the blowers that extract gas from the landfill are powered from the Walnut Substation, which blacked out in the earthquake. It was not restored untillate in the af- ,
ternoon. Without power to the blowers, the plant could not restan. A portable generator i was ordered, but required several hours to deliver because of the congested freeways ;
(partially caused by the closure of the daneged 1-5/1-605 interchange). '
At about 10:30 am, off-site power was lost for one-half hour when the local grid blacked out. On loss of normal ac power, the unintermptible power supply to the control room draws on its batteries. The UPS failed to provide adequate ac voltage, causing the f automatic control system to shut down Several batteries in the UPS were found to be [
defective, and had apparently been defective before the eanhquake. Fonunately, off-site ,
power was quickly restored and repair of the UPS was delayed until later. l The plant was restarted around 5:00 pm after the portable generafors arrived. l Plant startup and subsequent operation proceeded without problems. Close inspection of l 4 , the plant revealed no significant damage to either structures or equipment. Personnel re- !
poned that superficial cracks in concrete and reinforced masonry might have been earth- ;
quake-caused, or might have been preexisting and not noticed before the earthquake. !
(Reference C7, page B-13)
Rinaldi Receiving Station. At the Rinaldi Receiving Station, which experienced l an estimated ZPA of 0 5-0.75g during the magnitude 6.51971 San Fernando, California !
earthquake, several relay actuations were reported. They relay actuations were on typical ;
pilot wire and sudden pressure relays. (Reference Cl, pages 3-10 and 3-11)
San Cristobal Substation. At the San Cristobal Substation, which experienced !
an estimated ZPA of about 0.25g during the magnitude 7.81985 Chile canhquake, the substation was tripped offline during the canhquake when capacitor banks in the yard ;
failed and power was lost. It took about one hour to restore power, two hours to transmit I
power to the city, and four hours to return the substation to normal operation. Several relays were reponed to have actuated during the earthquake. Operators recounted that -
these were differential relays and sudden pressure relays. (Reference C1, page 4-16 and 4-17)
San Isidro Substation. At the San Isidro Substation, which experienced an esti-mated ZPA of about 0.6g during the magnitude 7.81985 Chile canhquake, the substation i
Programmatic Solutions C-15 Rev 0 6123193 The Readiness Operation
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was tripped offline during the carthquake. Operators indicated that the trip was due to ;
vibration of a protective relay (or relays)in the control room The emergency diesel gen- j erator started automatically with the loss of power and continued operating for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> i until power was restored. Damage in the 220 kV switchyard prevented resumption of ;
normal operation of the substation for over 3 days (Reference Cl, page 4-16)
San Sebastion Substation. At the San Sebastion Substation, which experienced :
an estimated ZPA of about 0.4g during the magnitude 7.81985 Chile eanhquake, the !
substation lost power during the earthquake when two protective " fault pressure relays" tripped. Afler an inspection, the relays were manually reset and normal operation was re- ;
sumed. Plant operators attributed these trips to oil sloshing in the transformers. ,
(Reference Cl, page 4-16) l Santa Cruz Water Treatment Plant. At the Santa Cruz Water Treatment Plant, !
which experienced an estimated ZPA of 0.4g in the magnitude 7.1 1989 Loma Prieta, Califomia carthquake, the plant was in operation at the time of the carthquake. Off site l power was lost immediately. The computer monitoring system continued to operate on ]
power from its uninterruptible power supply system. The emergency diesel generator j started automatically and operated until off site power from the grid was restored almost i 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the earthquake. !
The c.N1 generator is sized to supply all plant mechanical equipment, but water i treatment was suspended because ofinterruptions in the supply of raw water (the pumping j stations on the San Lorenzo River and Lock Lomand Reservoir have no source of backup power). Operations resumed almost 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the canhquake, when the local grid !
was brought up. l Mechanical and electrical systems in the plant were undamaged. There was no .
significant structural damage in the operations building, the sedimentation basins, or the !
I concrete water storage tanks, and only supedicial cracking in wall plaster and brick facmg. -
(Reference C7, page B-30) l Sangus Substation. At the Saugus Substation, which experienced an estimated -l ZPA of 0.35g during the magnitude 6.51971 San Fernando, California carthquake, in-spection of the plant log and conversations with plant personnelindicate that sudden pres-3 sure relays operated to remove the No 3 A 220/66 kV transformer bank from service. ,
The relays are typically mounted on the transformer between the oil reservoir and the main (
transformer body. Operators stated that alarms (no trips) were received on the No.1 A l' and 2A transformer banks. The alarms could have been caused by spurious relay actua-tion, but operators felt it is more likely that the failed lightning arrestors and insulators in the switchyard caused ground faulting, which in tum caused the alanns. (Reference Cl, ;
page 4-7 and 4-8) l t
UC Santa Cruz Plant. At the University of California, Santa Cruz cogeneration l plant, which experienced an estimated ZPA of 0 4g in the magnitude 7.1 1989 Loma Prieta, California earthquake, the diesel-generator was operating at the time of the canh-quake. The plant lost off site power, and the diesel-generator shut down as designed. The l Programmatic Solutions C-16 Rev 0 6/23193 The Readiness Operation
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operators checked for damage and, fmding none, manually restarted the diesel engine l However, when the diesel-generator was connected to the campus grid, the campus power ,
load was too large, and an underfrequency relay tripped the diesel off-line. Operators manually disconnected electrical supply at several buildings around campus and, with the reduced load, successfully re-started the diesels. The diesel was the sole source of campus power for about 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, until off site power was restored. (Reference C7, page B-25) .
Valley Steam Plant. At the Valley Steam Plant, which experienced an estimated ZPA of 0.4g during the magnitude 6.51971 San Fernando, California eanhquake, the se-ismic motion caused the actuation of a mercoid switch The oscillation of the mercury in the switch, which controls the low pressure fuel gas, caused the Unit 3 boilers to trip.
(Reference C2, page 18-5)
Based on discussions with later Valley Plant personnel, and on the operator's log, there were four spurious relay actuations that resulted from the seismic vibiations: (1) sudden pressure relay on the Bank F transfonner, (2) Unit 1 generator differential relay, .
(3) Unit 4 generator differential relay, and (4) Unit 3 low pressure fuel gas mercoid switch.
Units 1,3, and 4 were down at the time of the earthquake. Unit 2 was down for i maintenance. At the time of the canhquake, station power was being supplied to all three operating units from outside sources through Bus No. 2. Station power from Bus No 2 comes into the Valley switchyard at 230 kV and is converted to 138 kV by the Bank F transformer. The canhquake occurred at 6:01 a.m., and canhquake induced vibrations caused the sudden pressure on the Bank F transformer to trip the circuit breaker and cut off the outside station service power. This is a Buchholz type relay made by the Italian i company of Savigliano. The operators immediately attempted to energize Bus No. 2, but the breakers failed to reclose. The operators assumed the bus had been damaged. Fony- i eight minutes later, operators determined that the MG-6 auxiliary relay in the relay room :
had to be reset before the bus can be re-energized after a bus trip. The MG-6 relay acts as a lock out relay in the event of a bus trip, and was designed into the system to prevent '
premature resetting of the tripped breaker. Thus, the MG-6 relay is judged to have per-formed its intended function, and its locking out did not indicate a chatter condition during the earthquake. ,
Units 1 and 4 were tripped ofline by spurious actuation of their generator differ-ential relays. Unit 3 remained on line. However, during the confusion, operators assumed i that all units, including the station service, had been lost. Unit 3 boiler fires had been tripped from the oscillating of mercury in the low pressure fuel gas mercoid switch. When operators discovered that Unit 3 was still on the line, they energized the tie busses to sup- ,
ply Units 1 and 4 station service with power generated from Unit 3 (at 6:49 a.m.). The normal offsite station service power was restored at 7:54 a.m. !
The canhquake caused the turbine / generators in Units 1 and 4 to trip offline due to the spurious operetion of the generator differential relays. The relays are GE model CFD differential percentage relays, which are located on the control relay boards at eleva- !
tion 930 (15 ft above grade). (The principal of operation for the generator differential re- -
lay involves comparing the current entering one end of the transformer winding with the !
- current leaving the other end of the winding. When the current difference exceeds a cer- l J
1 Programmatic Solutions C-17 Rev 0 6/23193 The Readiness Operation ,
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tain value due to an internal fault, the relay closes its contact and causes a unit bus to trip.) [
Once operators had inspected the generators to ensure damage had not occurred Unit 4 was returned on line at 6.50 a m. and Unit 1 at 7:12 a m (Reference C1, pages 4-3 and 4-4)
Whitewater Hydroelectric Plant. At the Whitewater Hydroelectric Plant, which ,
I experienced an estimated ZPA of 0 5g in the magnitude 61986 Palm Springs earthquake, the plant was in operation at the time of the eanhquake. Vibration sensors on the impel-ler-generator tripped the plant during the earthquake. Leaks in the Colorado Aqueduct forced a reduction in flow while repairs were made over a period of several days. During this time, flow in the penstock feeding the Whitewater Plant was not available. Upon re- l turn of the aqueduct to full capacity, the plant was restarted without problems in any op-erating system. (Reference C7, page B-6)
Operator Response. In the following, available operator response to the earth-quake is briefly documented. Unless noted otherwise, these data are from Reference Cl.
Concon Refinery Plant remained operational through the earthquake. Emergency ,
diesel generator staned on loss of offsite power, but tripped offimmediately by relay ac-tuation. Operators manually restaned generator in 10 minutes and resumed operations.
El Centro Steam Plant 3. Unit tripped from grid but continued generating its own i station power after the earthquake. Operators placed the unit back on grid 15 minutes j after canhquake. However, the unit was limited to 10 MW due to lack of cooling tower fans because ofinoperative circuit breakers caused by build up of dirt and moisture. :
Problems corrected 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br /> after earthquake. About 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> later, operators manually tripped the unit to repair piping. Unit placed back on line about 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> later. l El Centro Steam Plant 4. Unit went completely black, loss of station senice power. Operators restored station senice from Unit 3 in 10 minutes. Inspection and re- :
pair of pipe leaks delayed returning the unit to senice until 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 20 minutes after the i earthquake.
Ellnfernillo. Both units remained on line, but plant disconnected from grid by outside system disturbances. Reconnected to grid after outside system restored (time un- ;
known).
Glendale. One and one-half hours after the canhquake, Units 3,4, and 5 tripped offline due to outside system disturbances (overcurrent relay trips). Operators diagnosed 4
the situation, reset the relays, and retumed all three units on line within 10 minutes. ;
Humboldt Bay 1 (1975). Unit tripped offline by relay actuation. Operators in-spected the unit, reset relays and breakers, and returned unit to service 19 minutes after }
the earthquake. t Humboldt Bay 2 (1975). Unit tripped offline by relay actuation. Operators in-spected the unit, reset relays and breakers, and returned unit to service 19 minutes after the earthquake. ,
Humboldt Bay 3 (1975). Unit down for scheduled maintenance. Mercoid switch !
actuation closed primary isolation valve. l Programmatic Solutions C-18 Rev 0 6123193 Tbe Readiness Operation
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Humboldt Bay / (19S0). Unit tripped offline by relay actuation. Operators in-spected the generator and placed it on line about 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> aner the euthquake. (No de- l tails available to explain why it took so long.) _
Humboldt Bay 2 (19CO). Unit manually ; ripped because of mercoid switch actua- -
tion. Operators had to correct additional problems before placing the unit on line about 8 !
hours after the eanhquake. j Krsko Nuc/ car Plant. Plant operators heard an audible sound caused by the earth- l quake that sounded like a passing freight train. They also noticed annunciation of an j eanhquake on the control panel.
They interpreted the audible canhquake sound as a rupture of non-safety class [
piping systems, and manually tripped the plant. Plant personnel performed detailed walk- !
downs of the plant and found nothing unusual except the spurious high water levelindica- l tion at the non-safety class level switches of the feed water high pressure reheaters. After :
the reset of the level switches, the plant went back on line and operated smoothly. i A magnitude 3.1 aftershock earthquake occurred several days later. It tripped the l plant automatically on an indication of steam generator high water level. Plant personnel j again performed detailed plant walkdowns. They found nothing unu;ual except that the j non-safety class low pressure feed water reheater had a spurious level switch indication of i high water level. C ich caused the high water level indication in the steam generator. Af-ter operators ress me level switches, the plant went back on line and operated smoothly. I (Reference C3) !
Magnolic 2. Lost outside station service power. Auxiliary generator started !
automatically, but operators could not stan the draft fans and feed pumps. Operators i manually tripped the fires and turbine. Operators inspected equipment and returned the !
unit to senice 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 45 minutes after the canhquake. f Magnolia 3. Fuel oil line broken in eanhquake Operator manually tripped the j unit due to low fuel oil pressure. Fuel line repaired and unit returned to senice 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 25 l minutes after the earthquake. ,
Magnolia 5. Unit offline at the time of the earthquake. Operators attempted to start it, but this was blocked by three relay actuations. Operators took 46 minutes to di- :
agnose the blocked start, reset relays, and bring the unit on line.
Olme 1. Unit was tripped offline by actuations of the generator differential relay. !
Outside statien service power was also lost. Thiny six minutes after the earthquake, sta- .
tion service power was made available from receiving station E. Operators reset relays, j purged and relit the boilers one hour after the canhquake. They placed the unit back on line 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 42 minutes later.
Olive 2. Unit tripped offline by actuations of the generator differential relay. ,
Outside station senice power was also lost. Thirty six minutes after the canhquake, sta- !
tion service power was made available from receiving station E. Operaters reset relays, i purged and relit the boilers one hour after the canhquake. They placed the unit back on j line I hour 47 minuteslater. !
OrmondBeach 1. Unit tripped by spurious actuations of relays. Several mercoid :
switches also actuated. Operators inspected the unit and returned it to service a shon time after the eanhquake. i i
h Programmatie Solutions C-19 Rev 0 6123193 The Readiness Operation I I
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i San Isidro Substation. Site lost power due to relay actuation. Diesel generator ;
started and remained on line until power was restored 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> later. Damaged transform-ers in switchyard delayed normal operation for 3-4 days. ,
San CristobalSubstation. Failure of capacitor banks in switchyard caused loss of ;
offsite power. It took about I hour to restore power,2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to begin sending power, and j 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to regain nonnal operation. ;
San Sebastian Substation. Station lost power from a transformer trip. Station in-spected, relays reset, and operations resumed. ,
Saugus Substation. Several sudden pressure relays actuated, tripping alarms and :
removing at least one transformer from senice. Station damage delayed retuming it to service.
Valley Stram L Outside station senice power was lost during the eanhquake, due !
to sudden pressure relay actuation. In addition, the units turbine generator was tripped off l line by differential relay actuation. Operators restored station senice power from Unit 3 19 minutes after the earthquake. Operators inspected the turbine generator and placed l unit back on line I hour 1I minutes after the earthquake.
Valley Steam 3. Unit 3 remained on line during the earthquake. In the confusion ,
however, operators believed all units went offline. Operators took 19 minutes to deter-mine that Unit 3 was on line, purge and relight the boilers, and energize Unit I and 4 aux- ;
iliaries. Operators had to relight the boilers because the actuation of a mercoid switch 1 shut off fuel to the boilers. l Valley Srcam 4. Outside station senice power lost during the canhquake, due to sudden pressure relay actuation. In addition, the units turbine generator was tripped off line by differential relay actuation. Operators restored station service power from Unit 3 19 minutes after the earthquake. Operators inspected the turbine generator and placed '
unit back on line 49 minutes after the earthquake.
Valley Steam. Outside station senice power lost during the eastaquake, due to sudden pressure relay actuation. A breaker failed to close when operators attempted to reenergize a bus. An auxiliary relay required resetting prior to closing the breaker. Op- ;
erators restored outside station service power 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 48 minutes after the earthquake. ,
f h
t l
Programmatic Solutions C-20 Rev 0 6/23/93 The Readiness Operation !
- - .. ~- . _ . - . . . , --. - . . . . - . .
i References for Appendix C j Cl. Gregory S Hardy, Michael J Griffin, Sam W Swan: 7he Performance ofRelays in [
Earthquakes: A Summary ofArailable Data, prepared for SQUG by EQE, October 1986. !
C2. Summary of the Seismic Adequacy of Tu enty Classes ofEquipment Requiredfor the i Safe Shutdown ofNuclear Plants, prepared for SQUG and EPRI by EQE Engineering, ,
March 1991. !
I C3. Chang Chen, Samir J Serhan, Zeljko Pavlosic: Erperience Data and AnalyticalRe- !
sults ofHigh Frequency Earthquakes, proceedings of the Fourth Symposium on Current Issues Related to Nuclear Power Plant Structures, Equipment, and Piping, December ,
1992. l t
C4. R McGuire, G Toro, T O'Hara, J Jacobson, W Silva: Probabihstic Seismic Ha ard l Evaluationfor OystalRiver Nuclear Generating Plant, prepared by Yankee Atomic l Electric, Risk Engineering, and Woodward-Clyde Consultants for EPRI, RP 101-53, April j
' 1989. !
C5. K M Skreiner, J D Stevenson, P R Wilson: Relay Behavior at the Perry Nuclear Power Plant During the 1986 Earthquake in Leroy, Ohio, prepared for the Electric Power i Research Institute, report NP-6472, September 1989. }
C6. J D Stevenson, P R Wilson: 1he 1986 Leroy, Ohio Earthquake: Performance of Power andindustrialFacihties, prepared for the Electric Power Research Institute by Stevenson and Associates, report NP-6558, November 1989.
{
. C7. AdvancedLight Water Reactor (ALWR) First-of-a-KindEngmeermg Project on i Equipment Scismic Quahfication, prepared for Advanced Reactor Corp by MPR Associ-ates, EQE Engineering Consultants, and ANCO Engineers. February 5,1993. ,
f n I i
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i i
Programmatic Solutions C-21 Rev 0 6/23193 The Readiness Operation 1
. , . . - . . . , . . , ~ ~ _ . - _ _ _ . . . - _ -. I
B t
6 Appendix D - Equipment-Specific Generic caveats ;
The purposes of this appendix are to describe any difTerences between the equip-ment caveats in Appendix B of the GIP and the caveats in the CR3 Plant Specific Proce-dure, and to explain the basis for the difference. Only those caveats where there is a dif-ference are included below If a caveat is not discussed below, the CR3 Plant Specific l Procedure adopts the GIP caveat.
Generic caveat CR3 Plant Specific Pro- Technical Basis for CR3 cedure Position on In- Plant Specific Position i clusion of Generic ca- i vcat
- 1. Motor Control Centers -
MCC/BS Generic Caveat #4 Genenc caveat is not in- Concern is structural in- '
Attached it'eight cluded because its intent tegrity of MCC. Concern :
is met by pre-screemng. ts not credible at a low ,
seismic site like CR3.
MCC/BS Genenc Cascat #7 Genenc caveat is not in- Concern is structuralin- ,
Cutours cluded because its intent tegnty of MCC. Concern is met by pre-screening. is not credible at a low seismic site like CR3.
MCC/BS Generic Caveat #8 Generic caveat is not in- Concern is carthquake Doors cluded because it's met by actuation of more r&s !
pre-screening. See Con- than operators can . vt clusion of Appendix C. Concern is not credible at ,
a low seismic site like CR3. See. Appendix C.
MCC/B5 Generic Caveat #9 Generic caveat is not in. Generic seismic capacity l 6 He Luna cluded because it's met by exceeds CR3 seismic de-pre-screening. mand at all frequencies.
including 8 Hz and be-low. See Appendix A.
MCC/BS Generic Caveat #10 Genenc caveat is in- Concern is structural in- ;
Anchorage cluded, but it refers to tegnty of anchorage.
{
CR3 approath an Appen- Concern is not very dix Einstead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site like CR3. See Ap- l nenc caveat willbe met pendix E. Anchorage j in implementation. reveiw is required, but detailed GIP approach is not required.
MCC/BS Genenc Caveat #11 Generic caveat is not in- Concern is carthquake Relays cluded because it's met by actuation of more relays pre-screening. See Con- than operators can reset.
clusion of Appendix C Concern is not credible at ;
a low seismic site like !
CR3 See Appendix C.
i
Cas eat CR3 P!:.nt Specific Technical Basis for CR3 Procedure Position on Plant Specific Position inclusion of Caveat
- 2. Low Voltage Switchgear LVS/BS Generic Caveat #3 Generic caveat is not in- Concern is excessive Breaker Restramt cluded because its intent structural response of ,
is met by pre-screening. breaker, based on high level test programs. Con-cert. b not credible at a low seismic site like CR3.
LVS/BS Generic Caveat #5 Generic caveat is not in- Concern is structuralin-
.4rtached if'eight cluded because its intent tegrity of LVS. Concern '!
is met by pre-screening. is not credible at a low seismic site like CR3.
LVS/BS Genene Caveat #8 Generic caveat is not in- Concern is structuralin- +
Cutouts cluded because itsintent tegnty of LVS. Concern is met by pre-screemng. is not credible at a low seismic site like CR3. ;
LVS/BS Generic Caveat #9 Generic camat for integ- One concern is structural -
i Doors rity is not included be- integnty. Concernis not cause itsintent is met by credible at a low seismic pre-screemag. Genene site like CR3. A second i
caveat for relays is not concern is canhquake included because it's met actuation of more relays by pre-screening. See than operators can reset. ;
Conclusion of Appendix Concern is not credible at C. a low seismic site like !
CR3. See Appendix C. !
LVS/BS Genenc Caveat #10 Generic caveat is in- Concern is structuralin- !
.4nchorage cluded, but it refers to tegrity of anchorage. I CR3 approach in Appen- Concern is not very ,
dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is required, but detailed GIP approach is t not required.
LVS/BS Generic Caveat #11 Generic caveat is not in- Concem is canhquake ,
Relays cluded because it's met by actuation of more relays pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at a low seismic site like i CR3. See Appendix C.
- 3. Medium Voltage Switchgear t 1
MVS/BS Generic Caveat #5 Generic caveat is not in- Concern is -tructuralin- l
.4ttached if ~ eights cluded because its intent tegnty of hWS. Concern I is met by pre-screening. is not credible at a low l seismic site like CR3.
l Programmatic Solutions D-2 Rev 0 6/23/93 The Readiness Operation
Cavert CR3 Plant Specific Technical Basis for CR3 Procedure Position on Plant Specific Position inclusion of Cascat MVS/BS Genene Caveat #8 Genenc c .e is not in. Concern is structural in-Curouts cluded '.,ccause its intent tegnty of MVS. Concern is m,t by pre-screening. is not credible at a low seismic site like CR3.
MVS/BS Genenc Caveat #9 G .nent caveat for integ. One concern is structural Doors r cy is not included be- integrity. Concern is not ause its intent is met by credible at a low seismic pre-screening. Generic site like CR3. A second caveat for relays is not concern is carthquake included because it's met actuation of more relays by pre-screemng. See than operators can reset.
Conchtsion of Appendix Concern is not credible at C. a low seismic site like CR3. See Appendix C.
MVS/BS Genenc Cascat #10 Genenc caveat is in- Concern is structuralin-Anchorage cluded. but it refers to tegrity of anchorage. 4 CR3 approach in Appen- Conectriis not very dix E instead of Section credible at a low scismic 4 4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is required, but detailed GIP approach is not required.
MVS/BS Generic Caveat #11 Generic caveat is not in- Concern is carthquake Relays cluded because it's met by actuation of more relays pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at a low seismic site like CR3. See Appendix C.
- 4. Transformers TRN/BS Generic Caveat #8 Generic caveat is not in- Concern is structural in-If *cak-II'ay Bendmg cluded because its intent tegrity of TRN. Concern is met by pre-screening. is not credible at a low seismic site like CR3.
TRN/BS Generic Caveat #10 Generic caveat for integ- One concern is structural Doors rity is not included be- integnty. Concern is not cause itsintent is met by credible at a low seismic pre-screening. Generic site like CR3. A second caveat for relays is not concern is canhquake included because it's met actuation of more relays by pre-screening. See than operators can ieset.
Conclusion of Appendix Concern is not credible at C. a low scismic sitelike CR3. See Appendix C.
The Readiness Operatson !
Programmatic Solutions D-3 Rev 0 6/23/93
Cavest CR3 Plint Specific Technical B sis for CR3 Procedure Position on Plant Specific Position ;
inclusion of Caveat TRN/BS Generic Caveat #11 Generic cas cat is in. Concern is structural in- .
Anchorage cluded. but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site hke CR3. See Ap -
nenc caveat will be met pendix E. Anchorage ,
in implementation.
reveiw is required, but detailed GIP approach is i not required.
TRN/BS Generic Caveat #12 Generic caveat is not in- Concern is carthquake Relavs cluded because it's met by actuation of more relays pre-screening. See Con- than operators can reset. t clusion of Appendix C. Concern is not credible at a low scismic site like CR3. See Appendix C. l i
- 5. Ilorizontal Pumps HP/BS Generic Caveat #4 Generic caveat is not in- Concern is excessive Pipmg cluded because its intent seismic loads from pip-is met by pre-screening. ing. Concern is not credible at a low seismic ;
site like CR3.
HP/BS Generic Caveat #5 Generic caveat is in- Concern is structural in- ;
BaseIsolatwn cluded, but it refers to tegnty of anchorage.
CP,3 approach in Appen- Concem is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site like CR3. See Ap- j neric caveat will be met pendix E. Anchorage ;
in implementation. reveiw is required. but detailed GIP approach is not required.
HP/BS Generic Caveat #7 Generic caveat is in- Concern is structuralin-Anchorage cluded. but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not wry ,
dix E instead of Section credible at a low scismic l 4.4 of GIP. Intent of ge- sitelike CR3. See Ap-
{
nenc caveat willbe met pendix E. Anchorage in implementation. reveiw is required, but ,
detailed GIP approach is l not required.
HP/BS Generic Caveat #8 Generic caveat is not in- Concernis carthquake Relays cluded because it's met by actuatian of more relays '
pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concernis not credible at a low scismic site like CR3. See Appendix C.
l
- 6. Vertical Pumps I
)
l Programmatic Solutions D-4 Rev 0 6123193 The Readiness Operation
Caveat CR3 Plant Specific Technical Basis for CR3 Procedure Position on Plant Specific Position inclusion of Caveat VP/BS Generic Caveat #3 Generic caveat is not in- Concern is excessive Piping cluded because its intent seismic loads from pip-is met by pre-screening. ing. Concern is not credible at a low seismic site like CR3.
VP/BS Generic Caveat #5 Generic caveat is in- Concern is structural in-Anchorage cluded, but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very da E instead of Section credible at a low seismic 4 4 of GIP. Intent of ge- site like CR3. See Ap-nenc caveat will be met pendix E. Anchorage .
I in implementation. reveiw is required, but detailed GIP approach is l
t not required.
VP/BS Generic Caveat #6 Generic caveat is not in- Concern is carthquake Relays cluded because it's met by actuation of more relays pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at a low scismic site like CR3. See Appendix C.
- 7. Fluid-Operated Valves l
FOV/BS Genenc Caveat #2 Generic caveat is not in- Concern is excessive CastIron Bodv cluded because its intent carthquake stresses in is met tw pre-screening. cast iron. Concern is not credible at a low seismic site like CR3.
FOV/BS Genene Caveat #3 Generic caveat is not in- Concern is excessive
, CastIron Fole cluded because its intent carthquake stresses in is met tw pre-screening. cast iron. Concern is not credible at a low scismic site like CR3.
FOV/BS Genenc Caveat #4 Generic caveat is not in- Concern is excessive Piping > 1 Inch cluded because its intent carthquake stresses in is met by pre-screening. piping. Concern is not uedible at a low seismic site like CR3.
FOV/BS Generic Caveat #5 & 6 Generic caveat is not in- Concern is excessive l'alve Operator Length cluded because itsintent carthquake stresses in )
is met by pre-screening. piping. Concernis not l credible at a low seismic I site like CR3. 1 FOV/BS Genene Caveat #7 Generic caveat is not in- Concern is excessive Actuator & Fole cluded becauseits intent earthquake stressesin I is met by pre-screening. yoke or shaft Concern is j not credible at a low l seismic site like CR3. I i
- 8. Motor- & Solenoid-Operated l Valves l
Programinatic Solutions D-S Rev 0 6123/93 The Readiness Operation l
l.
Cas cot CR3 Plant Specific Technicci Basis for CR3 i Procedure Position on Plant Specific Position ;
inclusion of Casest .
MOV/BS Generic Caveat #2 Generic caveat is not in- Concern is excessive t I
Cast /ron Bodv cluded because its intent carthquake stresses in is met by pre-screening. valve body. Concern is ,
not credible at a low scismic site like CR3. l MOV/BS Genene Caveat #3 Generic caveat is not in- Concern is excessive CastIron Fole cluded because its intent carthquake stresses in is met by pre-screening. yoke. Concern is not credible at a low scismic site like CR3.
MOV/BS Genenc Caveat #4 Genenc caveat is not in. Concern is excessive
+
Piping > / inch cluded because its intent carthquake stresses m is met by pre-screening. - piping. Concern is not credible at a low scismic site hke CR3, MOV/BS Genenc Caveat #5 Genenc caveat is not in- Concern is excessive Valve Operator Length cluded because its intent earthquake stresses in is met tn pre-screening. yoke. Concent is not
' credible at a low seismic :
site like CR3.
MOV/BS Genenc Caveat #6 Genenc caveat is not in- Concern is excessive ActuatorToke Braced cluded because its intent carthquake stresses in is met by pre-screening. yoke or shaft. Conocrn is not credible at a low scismic site like CR3.
1
- 9. Fans FAN /BS Generic Caveat #4 Generic caveat is not in- Concern is excessist Duct Distortmn cluded because its intent earthquake loads on fan t
is met by pre-screening. from ducts. Concern is not credible at a low seismic site like CR3.
FAN /BS Generic Caveat #5 Generic caveat is in. Concern is structuralin-Base Isolatwn cluded. but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very i dix E instead of Section credible at a low scismic 4.4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementatwn. reveiw is required, but detailed GIP approach is not required.
FAN /BS Generic Caveat #7 Generic caveat is in- Cor:ccrn is strecturalin-Anchorage cluded, but it refers to tegnty of anchorage.
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- sitelike CR3. See Ap- ,
pendix E. Anchorage ;
neric caveat will be met in implementation. reveiw is required, but l detailed GIP approach is l not required. ,
t Prograrnmatic Solutions D-6 Rev 0 6123/93 The Readiness Operation t l
I 1
Cascat CR3 Plant Specific Technical Besis for CR3 Proecdure Position on Plant Specific Position i Inclusion of Cascat j lo, Air llandlers ,
AIFBS Generic Caveat #2 Genenc caveat is in- Concern is structuralin-tegnty of anchorage.
)-
Anchorage-Internal cluded. but it refers to CR3 approach in Appen- Concem is not very -;
dix E instead of Section credible at a low seismic [
4.4 of GIP. Intent of ge- site like CR3. See Ap- t nenc caveat will be met pendix E. Anchorage l an implementation. reveiw is required, but [
detailed GIP approach is not required. ;
AH/BS Genenc Caveat #3 Generic caveat for integ- One concern is structural i Doors rity is not included be- integrity. Concern is not ,
cause its intent is met by credible at a low scismic pre-screemng. Generic site like CR3. A second l caveat for relays is not concern is carthquake l included because it's met actuation of more relays by pre-screening. See than operators can reset.
Conclusionof Appendix Concern is not credible at I
C. a low scismic site like CR3. See Appendix C. ;
AIVBS Generic Caveat #4 Generic caveat is not in- Concern is excessive ,
Duct Distortion cluded because its intent canhquake loads on air is met by pre-screening. handler from ducts. Con- l cern is not credible at a low scismic site like CR3.
AH/BS Generic Caveat #5 Generic caveat is in- Concern is structuralin- ,
Base Isolation c!uded, but it refers to tegrity of anchorage. ,
CR3 approach in Appen- Concern is not very L dix E instead of Section credible at a low seisnuc ,
4.4 of GlP. Intent of ge- sitelike CR3 See Ap- t nenc caveat will be met pendix E. Anchorage in implementation. reveiw is required, but >
detailed GIP approachis l
not required.
AIVBS Generic Caveat #7 Generic caveat is in- Concern is structural in- l Anchorage cluded, but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very l dix E instead of Section credible at a low seismic :
4.4 of GIP. Intent of ge- site like CR3, See Ap- [
neric caveat will be met pendix E. Anchorage j m implementation, reveiw is required, but detailed GIP approachis ;
not required. :
AH/BS Generic Caveat #8 Generic caveat is notin- Concern is carthquake
- Relays cluded because it's met by actuation of more relays (
pre-screening. See Con- than operators can reset. ,
elusion of Appendix C. Concern is not credible at alow seismic sitelike l CR3. See Appendix C. ,
l Programmatic Solutions D-7 Rev 0 6123/93 The Readiness Operation ;
1
L !
Carcet CR3 Pitnt Specific Technical Basis for CR3 l Procedure Position on Plant Specific Position ;
inclusion of Cascat
- 11. Chillers T
CinJBS Generic Caveat #2 Genenc caveat is not in- Concern is excessive !
Weak WayBendmg cluded because its intent carthquake loads on is met by pre-screemng. structural element. Con- [
cern is not credible at a low scismic site like CR3. j CHIJBS Generic Caveat #3 Generic caveat is m- Concern is structuralin- 1 Ba3e Isolation cluded, but it refers to tegrity of anchorage. ;
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is required, but detailed GIP approach is not required.
CHIJBS Genenc Caveat #4 Generic caveat is in- Concern is structural in-Anchorage cluded, but it refers to tegrity of anchorage. .
?
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is required, but ,
detailed GIP approach is not required.
CHIJBS Gem sic Caveat #5 Genenc caveat is not in. Oncern is earthquake Relays cluded because it's met by actuation of more relays pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at ';
a low seismic site like CR3. See Appendix C.
- 12. Air Compressors AC/BS Generic Caveat #2 Generic caveat is in- Concern is structuralin.
Base Isolation cluded, but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very dix E instead of Section - credible at a low seismic 4.4 of GIP. Intent of ge- site like CR3. Sec Ap- j neric caveat will be met pendix E. Anchorage in implementation. reveiw is required, but detailed GIP approachis not required.
AC/BS Generic Caveat #4 Generic caveat is in. Concern is structuralin-Anchorage cluded, but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very ,
dix E instead of Section credible at a low seismic i 4.4 of GIP. Intent of ge- sitelike CR3. See Ap-neric caveat will be met pendix E. Anchorage ;
in implementation. reveiw is required, but detailed GIP approach is not required.
Programmatic Solutions D-8 Rev 0 6123193 The Readiness Operation
Caveat CR3 Plznt Specific Technical Bisis for CR3 Procedure Position on Plant Specific Position inclusion of Caseat AC/BS Generic Caveat #5 Generic caveat is not in- Concern is earthquake Relays ciuded because it's met by actuation of more relays pre-screening. See Con- than eperators can reset.
clusion of Appendix C. Concern is not credibic at a low seismic site like CR3. See Appendix C.
- 13. Motor-Generators MG/BS Genenc Caveat #3 Genenc caveat is in- Concern is structuralin-Base Isolation cluded but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a low scismic 4.4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reverw is required. but detailed GIP approach is not required.
MG/BS Generic Caveat #5 Generic caveat is in- Concern is structural in-Anchorage cluded, but it refers to tegrity of anchorage.
CR3 approachin Appen- Concern is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent ofEe- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is required. but detailed GIP approach is not required.
MG/BS Genenc Caveat #6 Generic caveat is not in- Concern is carthquake Relays cluded because it's met by actuation of more relays
, pre-screemng. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at
(
I a low seismic site like CR3. See Appendix C.
- 14. Distribution Panels DP/BS Generic Caveat #2 Generic caveat is not in- Concern is about carth-Only Circuit BreaActs & Switches cluded because its intent quake vulnerabihty of is met by pre-screening, unspecified sub<ompo-nents. Concern is not credible at a low seismic site like CR3.
DP/BS Generic Caveat #3 Generic caveat for integ- One concern is structural Doors rity is not included be- integnty. Concern is not causeitsintentis met by credible at a low seismic pre-screening. Generic site like CR3. A second caveat for relays is not concern is earthquake included because it's met actuation of more relays by pre-screening. See than operators can reset.
Conclusion of Appendix Concern is not credible at 1 C. a low seismic sne like l CR3. See Appendix C.
Programmatic Solutions D-9 Rev 0 6/23/93 The Readiness Operation
r Cas cat CR3 Plant Specific Technical Basis for CR3 J Procedure Position on Plant Specific Position Inclusion of Caveat ;
i DP/BS Genene Caveat *6 Generic caveat is in- Concern is structural in- i
. Anchorage cluded, but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a lou seismic 4.4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage ,
in implementation. reveiw is required, but l detailed GIP approach is not required. ,
DP/BS Generic Caveat #7 Generic caveat is not in- Concern is canhquake !
Relays cluded because it's met by actuation of more relays ;
pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at a low seismic site like l CR3. See Appendix C.
l
- 15. Batteries on Racks l BAT /BS Generic Caveat #9 Generic caveat is in- Concern is structural in- !
cluded, but it refers to tegrity of anchorage. !
Anchorage CR3 approach in Appen- Concernis not very ;
dix E instead of Section credible at a low scismic 4.4 of GIP. Intent of ge- site like CR3. See Ap- i neric caveat will be met pendix E. Anchorage .!
in implementation. reveiw is required, but i detailed GIP approach is not required.
- 16. Battery Chargers & In-verteres L
BCl/BS Generic Caveat #4 Generic caveat is not in- Concern is excessive Weak-Way Bendmg ciudu!because itsintent earthquake loads on is met by pre-screening. structural element. Con-cern is not credible at a low seismic site like CR3.
BC1/BS Generic Caveat #6 Generic caveat for integ- One concernis structural !
Doors nty is not included be- integnty. Concern is not cause its intent is met by credible at alow seismic pre-screening. Generic site like CR3. A second l caveat for relays is not concern is canhquake r included because it's met actuation of more relays by pre-screening. See than operators can reset. l Concern is not credible at f Conclusion of Appendix C. a low seismic site like CR3. See Appendix C.
i Programmatic Solutions D-10 Rev 0 6/23!93 The Readiness Operation
?
Cascat CR3 Plant Specific Technical Basis for CR3 Procedure Position on Plant Specific Position Inclusion of Caveat BCl/BS Generic Caveat #7 Generic caveat is in- Concern is structural in-Anchorage cluded. but it refers to tegnty of an:horage.
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. rewiw is required, but i detailed GIP approach is not required.
BC1/BS Generic Caveat #8 Generic caveat is not in- Concern is earthquake Relays cluded because it's met by actuation of more relays pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at a low seismic sue like CR3. See Appendix C.
- 17. Engine-Generators EG/BS Generic Caveat #3 Generic caveat is in- Concern is structuralin-Base Isolation cluded, but it refers to tegnty of anchorage.
CR3 approach in Appen- Concern is not very dix 5i instead of Section credible at a low seismic 4.4 ot #T. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is required, but detailed GIP approach is not required.
EG/BS Generic Caveat #5 Generic caveat is in- Concern is structural in-Anchorage cluded, but it refers to tegnty of anchorage.
CR3 approachin Appen- Concern is not very dix E instead of Section credible at a low scismic r 4 4 of GIP. Intent of ge- site like CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is required, but detailed GIP approach is not required.
EG/BS Generic Caveat #6 Generic caveat is not in- Concern is earthquake Relavs cluded because it's met by actuation of more relays pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at a low seismic site like CR3. See Appendix C.
- 18. Instruments on Racks IR/BS Generic Caveat #2 Generic caveat is not in- Concern is that pro-Programmable Controllers cluded because it's met by grammable controllers pre-screening. are not adequately repre-sented by the carthquake l date base. They are now known to be adequately represented.
Programmatic Solutions D-11 Rev 0 6123193 The Readiness Operation l
l l
l
Cas eat CR3 Plint Specific Technical Basis for CR3 !
Procedure Position on Plant Specific Position inclusion of Caveat IR/BS Genene Caveat #5 Genenc caveat is not in- Generic scismic capacity ,
6 H: Limir cluded because it's met by exceeds CR3 scismic de-pre-screening. mand at all frequencies.
including 8 Hz and be-low. See Appendix A. '
IR/DS Generic Caveat #7 Generic caveat is in- Concern is structural in-Anchorage cluded. but it refers to tegrity of anchorage.
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site hke CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is requi ed. but detailed GIP approach is i not required. !
IR/BS Generic Caveat #8 Generic caveat is not in- Concern is carthquake Relays cluded because it's met by actuation of more relays i pre-screening. See Con- than operators can resetc l clusion of Appendix C. Concern is not credible at a low seismic site like CR3. See Appendix C.
- 19. Temperature Sensors No changes.
- 20. Instrumentation and Con- '
trol Panels and Cabinets '
I&C/BS Generic Caveat #2 Generic caveat is not in- Concern is that pro-Programmable Controllers cluded because it's met by grammable controllers by pre-screening. are not adequately repre- ,
sented by the earthquake data base. They are now j known to be adequately represented.
I&C/BS Generic Caveat #3 Generic caveat is not in- Concern is structuralin-Strip Chart cluded because its intent tegnty. Concern is not is met by pre-screening. credible at a low seismic site like CR3.
I&C/BS Generic Caveat #7 Generic caveat for integ- One concern is structural Doors ' rity is not included be- integrity. Concern is not cause its intent is met by credible at a low scismic pre-screening. Generic sitelike CR3. A second caveat for relays is not concernis earthquake !
included because it's met actuation of more relays !
by pre-screening. See than operators can reset.
Conclusion of Appendix Concernis not credible at :
C. alow seismic site like CR3. See Appendix C. I i
Programmatic Solutions D-12 Rev 0 6123193 The Readiness Operation I
Corcat CR3 Plant Specific Technical Basis for CR3 Procedure Position on Plant Specific Position Inclusion of Cascat I&C/BS Genene Caveat #9 Genenc cavest is in- Concern is structural in-
.1nchorage cluded, but it refers to tegnty of anchorage.
CR3 approach in Appen- Concern is not very dix E instead of Section credible at a low seismic 4.4 of GIP. Intent of ge- site Itke CR3. See Ap-neric caveat will be met pendix E. Anchorage in implementation. reveiw is required. but detailed GIP approach is not required.
I&C/BS Genenc Cascat #10 Generic caveat is not in- Concern is carthquake Relays cluded because it's met by actuauon of more relays pre-screening. See Con- than operators can reset.
clusion of Appendix C. Concern is not credible at a low seismic site hke CR3. See Appendix C.
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Appendix E- Anchorage ]
Background. The purpose of this section is to describe the basis for the CR3 ;
plant specific position on anchorage for GL 87-02. NRC's position on anchorage in GL 87-02 (Reference El) accurately reflects the consensus of the A46 program at the time:
"During the walk-through inspection, anchors andsupports of eqmpment within the scope ofreview will be carefully inspected. 7he de-tailed guidance developed is the preferred methodfor review of anchorages.
The detailedguidance has been developedjointly by SQUG and EPRI. It was approved by SSRAP and is being renewed by the NRC staff it will be approved by the NRC staff before implementation. If the adequacy afsup-ports and anchors cannot be determined by inspection. an engineering re- {
view of the anchorage or support will be conducted. This engineering re- l view willinchide a review ofdesign calculations or the performance ofnew ,
calculations and'or venpcation offundamentalfrequency ofequipment to ensure adequate restraint andstz[fness. ' (underline added)
CR3 Position. The CR3 plant specific procedure for GL 87-02 is very close to '
NRC's GL 87-02 position. However, some differences are logical since NRC's position in GL 87-02 is a generic one for all GL 87-02 plants (including the plant with the largest SSE), but CR3 is a low seismic site. The CR3 position is as follows: .
The preferred method to determine the adequacy of anchorage, support, andanchorage loadpath is through the inspection andjudgment ofSeismic Capability Engmeers (SCEs). SCEs should consider the an-chorage attributes in Section 4.4.1 of the GIP, as theyjudge appropriate, .
in their evaluation of the specific anchorage, support, or loadpath. If {
SCEs cannot determine the adequacy ofanchorage, support, or loadpath by inspection, then an engineermg review of the anchorage, support, or ;
loadpath should be conducted (which does not have to be performed by ;
SCEs). The engineering review shouldinclude a review ofexisting design calculations or the performance ofnew calculations.
I Basis for CR3 Position. The basis for the CR3 position is that the GIP overstates the anchorage issue for a low sei.cmic site. This is even illustrated by a comparison of the ;
above quote from GL 87-02 and the current guidance in the GIP (which applies for all GL 87-02 plants).
This is also illustrated by Reference E2, which summarizes a site and literature survey of the canhquake performance of anchorage. For example, Reference E2 docu- ;
ments over 360 cases of anchorage damage. Only about 20 of the 360+ cases of damage were in power plants. The pawer plant damage occurred when the free field ZPA was ;
0.25g or more, and the canhquake magnitude was large (greater than 7). Reference E2 also contains the following:
l Programmatic Sotutions E1 Rev 0 6/23/93 The Readiness Operation
" Friction chps andisolation-type anchorages, the anchorage of tall, thin electrical cabinets such as motor control centers, and the anchorage of massive items like large transformers and tanks are a source ofpoorper-formance. No damage wasfoundforpositive anchorage ofpumps and motors, pipe-mounted components such as valve operators, and devices mounted to control boards, relay panels, and electrical cabinets or ;
racks." -
"Past earthquakes have caused anchorage damage, but it is clear that ;
sufficient knouledge exists to engineer anchorage that willperform wellin :
future eanhquakes. "
Reference E3 contains the fallowing: " Failures are rare when criteria are equal l to or exceed equimlent lateralforces of 0.2W(0.2 times the weight of the equipment), {
even when thefree-field acceleration is 0.5g or more. "
7 This suggests the lateral force requirement for the CR3 SSE of 0.lg could be one- !
fifth of this, or 0.04W. In other words, this suggests CR3 equipment could be designed l for a seismic lateral force of only 4% of the weight of the equipment. We are not suggest- :
ing such an extremely ic u criteria. However, it does dramatize the different thought :
process called for when considering what is appropriate for a low seismic site. !
The presentation for Reference E3 contains the following:
" Experience data based criteria and insights include effects of workman- 1 ship, and design and construction errors:
- Some sites have poor workmanship, design & construc-tion errors .
@ fain Oil Plant, Clearly different Ihan nuclear) i
- With the exception ofitems like tanks and transformers, the errors appear to be isolatedrather thanpervasive ;
(Anchorage of 4 out of 8i MCCs in SQUG data base i were damaged)
- Tank and transformer anchorage damage may be mostly design error related I
- Workmanship apparently is not as important asfactors that can be (easily) checked l
- Does anchorage exist? l
- Are the number ofbolts enough?
-is the bolt diameterlarge enough?
- Are the nuts on the bolts?
-Is there enough weld? "' ,
Conclusion. It is good design practice to anchor equipment well. However,it is not difficult to design and install nchorage that will perform well in earthquakes. It is !
J also not difficult for qualified engmcers to use judgment to evaluate existing anchorage for a relatively minor earthquake like the CR3 SSE. Earthquake experience clearly suggests l l
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i the detailed GIP guidelines are not required for a low seismic site like CR3, and that the j above plant specific guidelir e is completely adequate to satisfy GL 87-02 at CR3.
i References for Appendix E E1. Verification ofSeismic Adequacy ofMechanical andElectricalEquipment in Op-erators, Unresolved Safetyissue (US1) A-46 (Generic Letter 87-02), US Nuclear Regula- ;
tory Commission, Febmany 19,1987.
E2. Paul D Smith: Compilation ofEarthquake Data on Equipment Anchorages, u; pub- !
lished, February 1988.
E3. W M Morrow, P 1 Yanev, P D Smith: Earthquake Performance in IndustrialFacili- ?
ties andits Relation to Nuclear Plant Equipment Anchorages, paper D 915, Transactions ;
of the 8th International Conference on Structural Mechanics in Reactor Technology, p 4
Brussels, Belgium, August 19-23, 1985. ,
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