ML19353B035
| ML19353B035 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 12/06/1989 |
| From: | Bournia A Office of Nuclear Reactor Regulation |
| To: | Morris K OMAHA PUBLIC POWER DISTRICT |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR TAC-71408, NUDOCS 8912110080 | |
| Download: ML19353B035 (11) | |
Text
.'
December 6, 1989 a
Docket No. 50-285 Mr. Kenneth L. Morris Division Manager - Nuclear Operations Onaha Public Power District 1623 Harney Street Omaha, Nebraska 68102
Dear Mr. Morris:
SUBJECT:
QUESTION AND COMMENTS Oh ALTERNATE CRITERIA AND HETHODOLOGIES, FORT CALHOUN (TAC NO. 71408)
TheNRC,withtechnicalassistancefromourconsultants(BrookhavenNational Laboratory), has reviewed your reports submitted by letter dated December 2, 1988. The proposed criteria cover piping and pipe supports, electric raceways, i
HVAC systems and associated expansion anchor bolts. You proposed the use of recent ASME Code cases including N-411, N-297 and N-451.
In eddition, several exceptions to Code requirements were proposed. They include plastic strain limits for piping, removal of operating basis earthquake stress from primary stress equations for piping, a twenty per ctnt increased yield strength for pipe supports to account for strain rate effects, a ductility ratio limit of three for pipe supports, use of experienced data in place of analysis for electrical raceways, and reduced safety factors for expansion anchor bolts.
To justify your proposed criteria, you have relied on several recent programs geared toward relaxation of seismic criteria. These include programs related to Unresolved Safety Issue (USI) A-46 resolution, seismic criteria developed for the Systematic Evaluation Program (SEP) plants, the SONGS-1 seismic reevaluation program and reconnendations docup.ented in NUREG-1061 and EPRI Report NP-5228.
While having been recouaended for some specific applications, the above programs are not directly applicable to Fort Calhoun without further plant specific assessment. The enclosure transmits our coments and questions as a result of our review findings. Therefore, ir, order to continue our review, please submit your response.
Sincerely,
/s/
Anthony Bournia, Project Manager kbbc bbbbbs5 Project Directorate IV P
PDC Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/ enclosure:
See next page D_ISTRIBUTION Uocket J11e NRC PDR Local PDR PD4 Reading G. Holahan F. Hebdon P. Noonan A. Bournia OGC-Rockville E. Jordan ACRS(10)
PD4 Plant File i
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December 6, 1989
. Docket No. 50-285 Mr. Kenneth L. Morris Division Manager - Nuclear Operations Omaha Public Power District 1623 Harney Street Omaha, Nebraska 68102
Dear Mr. Morris:
SUBJECT:
QUESTION AND COMMENTS ON ALTERNATE CRITERIA AND METHODOLOGIES,FORTCALHOUN(TACNO.71408)
The NRC, with technical assistance from our consulterts (Brookhaven Natienil Laboratory), has reviewed your rtports submitted by letter dated December 2, 1988. The proposed criteric ccver piping and pipe supports, electric raceways, HVAC systems and associated expansion ancher bolts.
You proposed the use of recent ASP.E Ccde cases including N-411 N-297 and N-451.
In addition, several excepticns to Code requirenents were proposed. They include plastic strain limits for piping removal of operating basis earthquate stress froc. primary stresseqbationsforpipirg,atwentypercentincreasedyieldstrengthfer pipe supports to acccunt for strain rate effects, a ductility ratio limit of three for pipe supports, use of experienced data in place of analysis for electrical raceways, and reduced safety factcrs for expansion anchor bolts.
Tc justify your proposed criteria, you have relied en several recent procrams geared towatd relaxetion of seismic criteria. These include programs reisted to Unresolved Sefety Issue (USI) A-46 resolution, seismic criteria developed for the Systematic Evaluation Program (SEP) plants, the SONGS-1 seismic reevaluation prc9 tam and recorrnerdetions documented in NUREG-1061 and EPRI Report NP-5228.
While having been recortaended for sont specific applications, the above programs are net directly applicable to Fort Calhoun without further plar.t specific a ssr tsr ent. The enclosure transmits our comments and questions as a result of cur.revicw finoings. Therefere, in order to continue our review, please submit your response.
l:
Sincerely, Sckw (l % g Anthony Bournia, Project Manager Project Directorate IV Division of Reactor Projects - III, IV, Y and Special Projects Office of Nuclear Reactor Regulatien
Enclosure:
l As stated l-cc w/ enclosure:
.See next page
l 4
1 Mr. Kenneth J. Morris Fort Calhoun Station Omaha Public Power District Unit No. 1 cc Harry H.- Voigt. Esq.
LeBoeuf, Lamb, Leiby & MacRae 1333 New Harrpshire Avenue, NW Washington, D.C.
20036-Mr. Jack Jensen, Chaiman 1
Washington County Board of Supervisors Blair, Nebraska 68008 t
Mr. Phillip Har ell, Resident Inspector U.S. Nuclear Regulatory Comission P. O. Box 309 fort Calhoun, Nebraska 68023 1
Mr. Charles B. Brinkman, Manager Washington Nuclear Operations Combustion Engineering, Inc.
12300 Twinbrook Parkway, Suite 330 Rockville, MD 20852 Regional Adirinistrator, Region IV U.S. Nuclear Regulatory Commission Office of Executive Director for Operations 611 Pyar. Plaze Drive, Suite 1000 Arlington, Texas 76011 Harold Borchert, Director Division of Radiological Health Department of Health 301 Centennial Mall, South P.O. Bcx 95007 Lincoln, Netraska 68509 Mr. G. R. Peterson, Manager Fort Calhoun Station P. O. Box 399 Fort Calhcun, Nebraska 68023
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'; NOV,21 '99'14:43
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Enclosure SMgpfants/Ouanitlems an *Alternata salatnie i
criteria and Methods 1selas fer Pt. calheun Statlan,
{
Yolunt.j" i
I samtien Entsta /oumatiana 2.0 acon i
2.0 o
Provide a description and discussion of how and When alternate criteria would be used, clearly delineate what aspects of a system would remain qualified by i
USAR criteria and what by alternate criteria, how i
boundaries between criteria are selected, etc.
I Provide exanples to illustrate.
4 i
clearly delineate which elements of the new criteria o
L wou111 be used for new designs or modifications.
3.O ALTERNQI 1ELgif C CRITrR_I&
3.0 o
Expand table 3.0-1 to show the governing codes and i
industry standards committed to in the USAR.
o Provide a
listing of all piping systems and delineate their intended ASME classification when goalified using the alternate criteria.
Provide a comparison of thess clasaltications to those used in the USAR.
Explain the rational to categorize ASME Code Class o
1 piping systems as anything but Class 1 (it is innlerred from Table 3.0.2 note "d" that systems usually considered class 1
will be normall i
qualified in accordance with class 2/3 criteria),y i
i o why is the use of ASNE B&PV Section III, 1980 Edition through suruner 1981 Addenda proposed?
Why not the most recent code edition?
What are the significant differences?
EPRI report NP-5228 ist not acceptable as a standard o
for anchor bolt criteria.
Provida alternate justification or criteria.
1
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NOV 21
- s9 14t C3 P.4/18 3.1 PIPINS AND PIDE BUDDORTg 3.1 o
Provide a comparison of the material, fabrfcation, inspection and QA/QC procedures used in the construction of the plant to the requirements associated with ASME Code class 1, 3 and 3 piping.
When the class 1 approach is used to exaltfy a systaa, how will these factors be addressed.
3.1.1.1 o
The NUREG 1061 recommendations on simplified fatigue evaluation and renoval of SI and SAM stresses from equation (9) have not been accepted by NRC.
Any propcsed code relaxations would require further plant-specific justification.
3.1.1.2 o
We believe that the Service Level D Stress limit of 2.4 sy given in Tabis 3.1-2 is in error and should be 2.0 Sy (according to current Code requirements).
Please confirm.
o The use of ASME Code Case N-451 has not been accepted by NRO.
Provide alternate justification or criteria.
L I
3.1.1.3 o
Application of Inole.stic strain criteria is not l
acceptable without further plant-specific justifi-l cation.
Staff acceptance of th;,s criteria for SONGS-1 Long Term se rvice (LTS) Program does not imply general staff e.cceptance for other plants.
3.1.1.4B o
Provide the technical basis for the generic support stiffnesses given in Table 3.1-3.
Demonstrate, by example, that a reduction of up to an order of Eagnitude does not impact the analysis results.
3.1.1.4C e
provide the basis for the main / branch pipe diameter ratio greater than or egaal to 3 as the decoupling criteria.
Provide a description of the methodology used to o
I perform a seismic inertia and sA,M analysis of -a decoupled branch lint.
Indicate how the main line notion is accounted for in the response spectrum inputs to the selszie inertia analysis.
3.1.1.4F o
Provide examples cf gecretries falling outside of code Case limits in which local stresses would be calculated baned on experimental or other analytical criteria.
f 2
Nov r1 'g9 toned P.5/10 p
3.1.1.40 o
summarine the procedure that would be followed if a leak-betere-break evaluation is performed in lieu of installation of pipe rupture hardware.
3.1.2.1 o
Provida typical charts or nomogra along with sr.pporting calculations.phs for review
~
Give an exarple of how a flexible valve may be o
supported such that its effects can be deocupist
. from the nomegraph-designed spans.
Provide the basis fer determining adeguate flexi-o bility for ar.chor actions.
3.1.2.2 o
Large bore criteria is stated to be an alternate evaluation method fer sr.all bore piping.
Pisase clarify the significance of this approach and l
delineate the specific differences that may result.
Will the exceptions to NC/ND-3600 rules proposed in the large bore criteria be applied?
i 3.1.3 o
Conpare the proposed design criteria for pipe supports with the usAR criteria.
What are the differences in safety margins?
i l
3.1.3.1 o
Demonstrate that the criteria given in Table 3.1-4 i
l_
comply with ASME Code Subsection NF requirements for standard ccaponent supports.
Table 3.1-4 (Design criteria for Standard Component o
suppcrts) a13cvs ;! tinos manufacturer recommended Level A - capacity as the faulted (Level D) limit.
It also requires a minimum safety factor of 1.5 for Level D.
How is the 1.5 safety factor assured if the manufacturer provides only Level A limits and no ultimate load Linits?
3.1.3.2 o
Table 3.1-5 Applicable Code column lists ASME and deviations.
Define all deviations and provide justifications for their use.
Various Table 3.1-5 limits include a factor of 1.2.
o Is this the factor which accounts for strain rate and average strength effects?
Provide additional justification for the 204 strength increase.
The NRC acceptance of this criteria for the SONGS-1 LTS i
progran does not imply acceptance for all plants.
The ductility limit of 3 is not acceptable. The NRC o
acceptance of this criteria for the sono-1 LTs program does not apply to all plants.
Provide alternate criteria or justification.
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5 compare the proposed criteria for welds, structural o
J bolts, and base plates with the UsAR criteria.
s.n rLuemeAt nemvm 1
l 3.2, o
Provide justification for not performing seismic l
evaluations ior conduits and cable trays.
If the basis is seistic experience, provide the seismic
~
experience data which substantiates the adequacy of l
the span length table used for Ft.
Calhoun electrical receways.
The data should demonstrate the similarity of span configuration, seismic
- levels, materials, censtruction characteristics, etc.
i o
compare the proposed criteria for electrical raceways and supports with the USAR criteria.
What are the differences in safety margins?
3.2.1 o
Is the 0.6 yield strength allowable the basis for the manufacturer recortended conduit spans or will plant-specific condu.it span tables be developed?
o If conduit stresses shall not exceed 0.6 yield strength undur gravity load, what stress levels would be expected under gravity plus seismic load?
The proposed span ;* ength criteria for conduits does e
L not consider horizontal loading.
Provide the l
allowable sptna for horizontal restraint in both the transverse and. Inngitudinal directions of the conduit axis and describe their basis.
3.2.2 o
provide the technical basis for manufacturers I
catalog cable tray span allowables.
What maximum stresses een be expected for gravity loads and seismic loads;?
toen the aanufacturer specify a s
maximum cable fill? Describe the procedure used to increase the allowable span for " lightly loaded" cable trays.
Does the manufacturer allow cable fill above the top o
of the side rails?
Describe how cables are tied to the cable trays.
Provide the basis for the seismic adequacy of this configuration.
3.2.3 o
Describe the nothods that will be used to determine the electrical raceway support loads.
Define the required loads and load combinations for each plant operating condition.
L 4
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3.3.3.1 o
For hot-rolled steel raceway supports, will the 30%
increased yield strength or the maximum ductility of 3 as proposed for pipe supports be allowed?
If so, provide justification.
80NG8-1 LTS program criteria are not acceptable.
)
3.2.3.2 o
Provide the basis for the allowable stress increase factors of 1.33 and 2.0 for cold-formed steel raceway supports.
Will these factors be applied to all stress limits including buckling limits?
3.2.3.3 o
Provide the basis for the allowable stress increase l
factors of 1.33 and 2.0 for catalog items based on manufacturer's allowable loads. Against what limit will a minimum safety factor of 1.5 be maintained?
For qualification of catalog items by analysis, will l
9 the 30% increased yield strength or the maximum ductility of 3 as proposed for pipe supports be allowed?
If so provide justification.
80NG-1 LTS i
program critoria are not acceptable.
i i
custify the applicability of the proposed cyclic o
load rating pre.cedure to electrical raceway l
supports.
It appearn to be based on ASME Code Case N=430 which covers energy absorbing supports.
rurtharnere it addrenses only cyclic seismic loads, i
Normal loads (deadwnight, thermal, etc.) are not included.
3.2.4 o
will conduit clamps and cable tray clips provide restra. int in the Isr.gitudinal direction?
Will friction be relied upon and considered in the i
evaluation?
3.5 MvAc e
3.3.1 o
compara the proposed criteria for qualification of NVAC ducts with USAR criteria.
What are the differences in safety nargins?
l 3.3.1.1 o
Define the loads, load combinations, and corres-pending plant oportting conditions for use in qualification of HVAC ducts and supports.
Will any exceptions to AISI or ASME Code stress o
allowables be taken for EVAC ducts? If so, justify.
5
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3 3.1.3 o
Provide an example to illustrate the methodology that will be used to qualify NVAC ducts and supports by experience data, and identify the sources of the experience da.ta to be referenced.
3.3.2.1 o
For MVAC suports,imum ductility of 3 as proposed will the 30% increased yield I
strength or tne ma.x for e sup be allowed?
If so provide cation. ports just 3.3.3.1 o
Justify the allowable load increase factors of 1.33 and 2.0 for amargency and faulted load conditions for qualification of MVAC support hardware using manufacturer's allowables.
I i
LJ CONCRETE _IXPAMBI]ltH AFCigl33 j
3.4.2 o
EPRI report NP-5218 dcas not provice an acceptable basis for use of reduced safety factors, modified tensien-shear interaction formula, and modified edge distance and spacing requirements for expansion anchors.
provice-additional-justification or alt, ornate criteria..
3.4.6 o
Provide justifica"lon for embedmont depth of 1/4 inch less then the minimum specified in the nanufacturer's catalog.
l 3.4.7 o
Provide the technical basis for the proposed criteria ter anchors installed in concrete topping including Table 3.4-1.
3.4.8 o Justify the factor of 1.5 on anchor bolt tension load to account for base plate prying.
4.e mrRNATF ANALQUEKQQQgg 4.1 Loan augg 4.1.3 o
Provide cenparisons of floor response spectra between the 1970 and the updated analysis.
Explain the differances.
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The use of ASME Code Case N-411 damping in a multiple level response spectrum analysis is not acceptable without further justification.
Regula-tory Guide 1.84 currently limits the use of 5 411 damping to single level response spectrum analysis.
ll 4.2.1.1 o
NRC acceptance of the song 8-1 LTS program methodology la not sufficient justification for the use of the CQC method of modal combination. Provide plant-specific justification or alternate j
methodology.
j i
o Demonstrate the adequacy of the random vibration method for independent support action combinations l
by comparison with time history analysis results.
j o
Provide justification for combination of SAM j
stresses and renetions with seismic inertial j
stresses and reactions by the sRss method.
4.2.1.2 o
How will the licensee. Identify piping systems in which stress corrosion cracking has occurred for which Code caise N-411 danping wi31 not be allowed?
4.2.1.3 o
Is sRss conbination of SSE with LOCA or water hammer / stear. hammer loading consistent with USAR criteria?
4.2 1.4 o
The use of AsME Code case N-397 on spectral peak shif ting is esece tions on a casse ptable for specific plant applica-by-case basis per Regulatory Guide 1.84. Provide a plant specific assessment on safety margin using this methos versus the peak broadening method.
4.2.2 o
Justify the use of ASME code Case N-411 dar. ping with the equivalent static coefficient method of analysis.
Regulatory Guide 1.44 currently limits its use to responsis spectrum analysis.
Table 4.2-1 defines an equivalent static coefficient o
of 1.5 for non-rigid systems. Under what conditions would a icwer coefficient be used for non-rigid systems and how would it be justified?
When the equivalent sta. tic coefficient method is e
used, how will the system fundamental frequency be determined if no dynnnic analysis is performed?
7
NOV r1 '99 14 t M P,1gegg I
i 4g2 3
.o Ixplain how both socaleration and displacement notions will be ocnsidered at support points.
Explain the method that will be used to perform o
I independent support action time history analysis.
Will different support motions be applied staul-taneously? If so, why is support level combination necessary? Will the method distinguish between the inertial components and the psuedo-static components 1
of response?
o Clarify when a SAM analysis would be performed versus an independent support motion analysis.
l 4.2.4.1 o
The staff does not accept the use of ductility demand response spectra in piping system seismic analysis.
c 4.2.4.2 o
Application of inelastic strain criteria is not
[
soceptable withou; further plant-specific justification.
See cor.nent on 3.1.1.3.
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d3 ELECTRICAL RACEWAYS i
4.3.1 o
Describe the methods that will be used to calculate fundaxental frequency of an electrical raceway syster..
If single span nodels are used, will the frequency and spectral acceleration vary between different spa.ns within the same systen?
o Describe.the methods that will be used to calculate tributary lengths for complex systems.
Provide
- examples, o
Provide the basis for the proposed danping ratios for conduits and cable trays. Demonstrate that test progran results arei applicable to Ft.
Calhoun conduit and cable tray systems.
o Demonstrate the adequacy of the procedure for SRss combination of support loads in multiple tiered supports.
d.4 UyAg 4.4 1 o
For a
representative HVAC
- system, provide a
calculation to demonstrate the seismic evaluation of NVAC ducts and supports by the equivalent static nethod.
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