ML20070P860
| ML20070P860 | |
| Person / Time | |
|---|---|
| Site: | Clinch River |
| Issue date: | 01/24/1983 |
| From: | Longenecker J ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT |
| To: | Check P Office of Nuclear Reactor Regulation |
| References | |
| HQ:S:83:192, NUDOCS 8301260407 | |
| Download: ML20070P860 (19) | |
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9 Department of Energy Washington, D.C. 20545 Docket No. 50-537 HQ:S:83:192 JAt:
EB3 Mr. Paul S. Check, Director CRBR Program Office Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Check:
ADDITIONAL INFORMATION ON MECHANICAL ENGINEERING BRANCH (MEB) ITEMS 50 AND 70
Reference:
Letter HQ:S:82:093, J. R. Longenecker to P. S. Check,
" Meeting Summary for MEB/CRBRP September 8 and 9,1982, Meeting," dated September 21, 1982 Enclosed are responses to MEB concerns 50 and 70, and associated revised Clinch River Breeder Reactor Plant Preliminary Safety Analysis Report (PSAR) pages, that will be included in a future PSAR amendment. This submittal provides the remaining responses due the MEB on low temperature concerns identified in the referenced letter.
Questions regarding the enclosuresmay be addressed to Mr. D. Robinson (FTS 626-6098) or Mr. D. Florek (FTS 626-6188) of the Oak Ridge Project Office staff.
Sincerely, Jo n R. Longene er Acting Director, Office of Breeder Demonstration Projects Office of Nuclear Energy 2 Enclosures Qf cc: Service List O
Standard Distribution Licensing Distribution S
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8301260407 830124 PDR ADOCK 05000537 A
ENCL 0EURE Item #3.1-17
Title:
MEB Item 50
^
Does the reactor i:ool nt boundary design, which was made to
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Description:==
Code Editions and Code Cases at least five years old, provide a comparable level of safety to a similar design made to current Code Editions and Code Cases.
A i.e.9 rough review has been completed, for CRBRP primary system
Response
components, of the impact of changes between the 1974 Edition of the ASME Boiler and Pressure Vessel Code, and the 1980 All Edition, including Addenda through the Summer of 1982.
the specific changes that have occurred in the design rules have been examined, and Table 1 attached lists the design rule Table 2 changes that are more restrictive than the prior rules.
lists the Class 1 primary' pressure boundary components whose low-temperature design criteria were evaluated (changes in the dcsigi, rules for the elevated temperature portions have previously beenidentifiedandevaluated). Table 3 summarizes the potentially applicable design Code Cases.
The structural integrity significance of each item in Table 1 to each pr%ary coolant pressure boundary component in Table 2 has been determined, and the results are provided in Attachment A.
Based upon the results of this review, it is concluded that the CRBRP primary pressure boundary components have a higher level of assured structural integrity than the minimum values provided by the current Code design rules.
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TABLE 1 ASME BOILER CODE SUBSECTION NB-3000 (SUPT 1ER 1982)
CHANGES THAT ARE MORE RESTRICTIVE THAN 1974 CODE NB-3100 Standard Products Table NB-3132 The referenced standards are upda 1.
and further restrictions were added to several standards.
The NB-3136 exemption from post-weld heat treating of ferritic nozzle and 2.
branch connection welds was removed.
The vessel fillet weld requirements were extended to cover all components 3.
(NB-3123.2).
J The stress categorization of shell-to-head Junction bending stresses was 4.
changed from Q to P when bending edge constraint is necessary to me head bending stress limits.
limit based on the fully plastic section factor was S.
An additional P +Pb t
added to NB-3221.3.
An additional P, limit was added to NB-3224 for pressure loadings of 6.
ritic components.
limit for testing was reduced when P,>0.67 S.
y 7.
The P,+Pb The peak stress indices for openings in shells of NB-3338.2(d) and NB-3 were restricted to cases where the opening d is less than.8[D't*
8.
The peak stress indices for openings in shells of NB-3338.2(d) and NB-333 9.
were restricted to cases where at least 40f. of the reinforceme f
outside of the shell.
The piping "B" indices of NB-3600 were restricted to cases where D 10.
other indices were changed.
No primary This list does not include changes in NB-3400 or NB-3500.
Note:
l system components have been located that use these two strbarticles.
No CRBRP primary system design related Code Cases have been found that re sult in more restrictive rules in 1982 than in 1974.
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TABLE 2 LIST OF ASME CONSTRUCTION CODES. CODE CLASSIFICATIONS.
AND CODE CASES FOR LOW TEMPERATURE CRBRP PRIMARY PRESSURE BOUNDARY COMPONENTS Low Temperature Code / Code Class Design Applicable Code Cases and Component Edition / Addenda Subarticles Rev_i s_ ions Reactor Vessel & Primary Heat Transport System ReactorVessel(1)
ASME III/l NB-3100, NB-3200, 1521-1, 1682, 1974/ Winter '74 and NB-3300 1690 Closure Head (1)
ASME 111/1 NB-3100, NB-3200, 1521-1, 1682, 1974/ Winter '74 and NB-3300 1690 Primary Sodium Pump (1) ASME 111/1 NB-3100, NB-3200, 1521-1, 1682 Casing 1974/ Winter '74' and NB-3300 Intermediate Heat ASME 111/1 NB-3100, NB-3200, 1521-1 Exchangers IllX 1974/ Summer '74 and NB-3300 (Rubes and Shell)
Primary Piping ASME 111/1 NB-3100 and NB-3600 1644-4 1974/ Summer '75 Primary Sodium ASME 111/1 NB-3100, NB-3200, Overflow Vessel 1974/ Summer '76 and NB-3300 Primary Sodium ASME 111/1 NB-3100, NB-3200, 1685-1 Makeup Pumps 1974/ Summer '76 and NB-3300 l
Overflow and Primary ASME 111/1 NB-3100 and NB-3600 Sodium Makeup Piping 1974/ Summer '75 l
and Fittings I
l Thermal Transient ASME 111/1 e,
NB-3100, NB-3200, 1539, 1685, N62-2 Valves 1974/ Summer '76 and ND-3300 Check Valve ASME 111/1 NB-3100, NB-3200, 1685 1974/ Summer '76 and NS-3300 Overflow Heat ASME 111/1 NB-3100, NB-3200, 1644-6, 1681-1 Exchanger 1974/ Summer '76 and NB-3300 Notes:
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(1) Code cases 1682 and 1690 are permitted for use if the supplier elects to use them.
TABLE 3 tect C45t$ TMAT C010 HAvi EttJI 1;5ID FOR THE CPER FR1mPV (00LANT PLACTC9 ntS$utt 20umEARY C08F0ntals Relevast to Lsploraation Design tode h e hatfr h$)til use of H-Grades is irrelevaat te los temperature rules to 1521 use of et Grades of Stataless Steel Valve must be designed u4% metal seal Presumed to be ineffective thot to Pressure Boedary 15ys stetal tellous & lirtal C6aphrsgn Sten Scaled Valves Relates to corponent supports - not to Class 1 compaments themselves 1644 Addittenal %terials for Crugonent Serports and flot to design of Class 1 items Altemate besign Paquirements for Bolted Joiets Isot design specific fic 16El Organt:ations Acceptfag Cverall Pespcesibility for Section !!! Coristraction Only a material sappiter qualffication issue Ino 1682 Alternative teles for Material Mannfactorers
$10
- tsed only for brazing valve seals Not as used in CRBRP 1685 ferf ace Braling bly a anterial supply geestion 10 0 1690 Stock hterials for Section !!! Construction llot esed in the CER valves The design was based om design-by-amelysts 0 62-2 laternal and Enternal valve Items
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(1621)
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ATTACHMENT A AN EVALUATION OF THE TEN POTENTIALLY SIGNIFICANT CHANGES IN THE ASME CODE CASE I DESIGN RULES FOR THE CRBR PRIMARY COOLANT PRESSURE BOUNDARY COMPONENTS I
hote: ~See Table 1 for the list of the ten potentially significant Code design rule changes.
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Main Coolant Pump 1.te,m, l.
No Standard Products were used in the pump.
2.
Not applicable because component is austenitic steel.
3.
Fillet welds are not used on the pressure boundary thus the changes are not applicable.
4.
The head bending stress values are low, and thus the head pressure-induced bending limit can be met with fully free to rotate head supports.
5.
The cross-sections are solid rectangular thus the new a factor lir.its result i.i no change.
6.
The component is austenitic steel so that the change is not applicable to the pump.
7.
The test pressure stresses are low thus the modified stress limit is not encountered.
8, 9. The peak stresses were determined using detailed analysis, not the stress indices of NB-3338 or NB-3339.
10.
Not applicable because the pump was designed using vessel (not purp) design rules.
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1 I
Main Primary Coolant System Piping Item The changes in the referenced standards are not signficant to these 1.
components.
Not applicable because NB-3136 refers to ferritic nozzles while the 2.
CRBR primary piping is austenitic.
Not applicable because fillet welds are not used in the main primary 3.
coolant system piping.
Not applicable because the piping does not involve a shell to formed 4.
head junction.
Not applicable because the main primary coolant system piping is 5-9.
designed as piping not as a vessel.
The revised piping stress indices do not result in a singificant (to 10.
the rain coolant piping) change in stress limits. The main coolant piping uses only a few of the indices, some of the indices are reduced which partially offsets the increases in other indices, and the margins by which the existing rules are met assure that the revised indices can be accommodated.
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Intermediate Heat Exchanger _
Item 1.
No Standard Products were used.
2.
Not applicable because th I}Xisaustenitic.
3.
Not applicable becausegfillet welds are not used.
The only places where significant center-of-head bending stresses 4.
In one tubesheet the pressure occur are in the two tubesheets.
bending stresses are low enough that it is clear that edge effects are not significant.
In the other tubesheet, while the tubesheet pressure-induced bending stresses are high, the shell thickness is so low (1 1/2 inches) compared to the head (11 inches thick) that limit to be edge constraint (if released) cannot cause the P +P g b exceeded.
The cross sections are all solid rectangular thus the recent rules 5.
changes have no effect.
6.
The component is austenitic.
The test pressure stresses do not exceed the current limits.
7.
Fatigue stresses are obtained froia detailed analyses, not from 8.
NB-3330 stress indices, ide v 9.
See the answer to quettien 8 10.
Not applicable to vessels.
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ltem 1.
No Standard Products were used.
Not applicable because the component is austenitic steel.
2.
Not applicable because fillet welds were not used.
3.
Not applicable because the center of head bending streses are 4.
well below Code limits.
All sections are solid-rectangular thus the changes are not significant.
5.
Not applicable because the check valve is made of austenitic stainless 6.
steel.
The testing stresses are low thus the recent rules changes are not 7.
applicable.
Detailed 8, 9. The fatigue stress indices of NB-3338 or -3339 are not used.
analysis is used instead.
10.
Not applicable to the check valve.
This item was designed using vessel not valve design rules.
Note:
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Reactor Vessel and Closure Head 1.
Not applicable because Standard Components have not been used.
2.
Not applicable because carbon or low-alloy steel nozzles have not been used.
3.
Fillet welds have not been used on the primary coolant pressure boundary.
4.
The only flat head is the closure head. The low head bending stresses due to pressure (s 1000 psi) and the large head thickness preclude violation of footnote 5 to Table NB-3217-1.
5.
All sections used a=1.5 and all sections are solid rectangular thus the change does not affect the reactor vessel and head.
6.
There are no significant Level C pressure loads on the ferritic portions.
7.
The margins for testing stress levels assure that the current P +Pb L
limits are satisfied.
8, 9.
The fatigue evaluations of the nozzles were based on design-by-analysis, not the stress indices.
10.
Not applicable to vessel and vessel closures.
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Overflow / Makeup Piping Item 1.
No significant effect on the design.
J 2.
!;ot applicable to this austenitic SS piping system.
3.
No fillet welds were used.
4-9.
Not applicable to piping.
The 0/M system piping meets the limits with the current stress 10.
indices.
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Overflow / Makeup Valves (Thermal Transient Valves)
Item 1-9.
All the valves were designed to the elevated temperature rules.
They were designed-by-analysis as vessels. They are all austenitic SS.
None of the low temperature design rule changes thus are relevant.
10.
The piping rules changes are not applicable.
(
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Overflow /Makeuo Vessel, Heat Exchanger, and Pump Item 1.
No structural impact.
2.
These components are not ferritic.
3.
No fillet welds are used.
The center-of-head pressure bending stresses are within Code limits 4.
without rotational edge constraint.
5.
All a factors are 1.5.
6.
Tnese components are not ferritic.
7.
These limits are satisfied.
Where design-by-analysis rules were not used the openings are not large.
- 8. 9.
- 10. Not applicable to vessels.
These components were all designed as vessels using design-by-analysis.
Note:
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MEB Item 70:
The information on load combinations and emergency limits in PSAR Sections 3.9.2/3.7A is incomplete.
Coverage equivalent to that in current SARs (e.g.,
the Byron PSAR) should be provided.
Response
PSAR Section 3.9.1.6 has been modified to include requirements for component supports.
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3.9.1.6 Analvtical Methods for ASME Code Class 1 Comeonents and 1
Comoonent Sucoorts The design transients for these canponents are described in Appendix B of this PSAR. The analytical methods and stress limits will be discussed in the FSAR.
The evaluation of ASME Code Class I components and component supports wil!
comply with the requirements of the 1974 Edition of the ASME Boiler and Pressure Vessel Code Section li t, Subsection NB (canponents) and NF (supports). The subsection NB requirements for components are supplemented by the following:
(1) Low Temeerature Comeonents (below 8000fli RDT Standard E15-2NB-T, October 1975.
Regulatory Guide 1.48, " Design Limits and Load Combinations for Selsmic Category i Fluid System Components."
(2) E levated Temoerature Comoonents (above 8000 ELL (a)
Interpretations of the ASME Boiler and Pressure Vessel Code Case 1592, " Class 1 Components in Elevated Temperature Service Section lil".**
(b) RDT Standard F9-4T, " Requirements for Design of Nuclear System Components at elevated Temperatures" Jan.1976.
(c) RDT Standard E15-2NB-T, October 1975.
The inelastic and limit analysis methods having the stress and deformat!on (limits) established by the ASME Code, Section lil, ar.d Code Case 1592 (elevated temperature design) for normal, upset and emergency conditions may be used with the component dynamic analysis.
For these cases, the limits are l
suf ficiently low to assure that the dynamic elastic system analysis is not l
invalidated.
For the case of elevated temperature components designed in accordance with Code Case 1592, conservative deformation (or strain) limits have been formulated to help ensure the applicability of the other rules of the Code Case; i.e. the strain limits in Code Case 1592 are set conservatively low such 1 hat they ef fectively ensure that small deformation theory is applicable for i
most structural analyses of elevated temperature components. The small l
deformation assunptions, which have been the cornerstono for analyses of structures at low temperatures, are retained by the majority of current computer structural models being used for elevated temperature analysis.
- There are no deviations at present.
All supplemental criteria will be f ully identified and justified in the FSAR.
3.9-3 Amend. 75 nma omet
The elevated temperature Code Case places the following limits on the maximum accumulated inelastic strain for component parent material (Section T-1310 of l Case 1592):
1.
Strains averaged through the thickness,15 2.
Strains at the surface due to an equivalent linear distribution of strain through the thickness, 2%
These limits are consistent with the NRC Standard Review Plan, Section 3.9.1, which states that small def ormation methods of analysis typically tend to have ac<,eptable ef f ective strain limits in the range of 0.5 to 1.5 percent.
For components designed in accordance with the low temperature rules of Section lli of the ASME Code, the 3 Sm limit on primary-plus-secondary stress ensure the applicability of small deformation theory:
1.e., the 3 Sm limit ensures shakedown and precludes ratchetting.
For f aulted conditions, the plastic and limit analysis stress and def ormation limits are specified in Appendix F of the ASME Code, Section Ill. These limits are established in terms of an equivalent adopted elastic limit which can be used with a dynamic elastic system analysis.
Particular cases of concern will be checked by use of simulated inelastic internals properties in the clastic system analysis.
At the component level, use of plastic or inelastic stress analysis or application of Inelastic stress and deformation limits may be used with the elastically calculated dynamic external loads provided that shakedown occurs (as opposed to continuing def ormation) or deformations do not exceed specified limits.
Otherwise, readjustment to the elastic system analysis will be required. A list of components for which inelastic analysis has been perf crmed or is planned is shown' in Table 3.9-11.
Complete system inelastic methods of flexibility analysis combined with inelastic stress techniques may be used if there is justification.
Design loading combinations to be used f or ASME Section lil Class 1 components are those as given in Appendix 3.7-A with the additional combinations given below.
Normal and Emergency Conditions: Dead + Live + Operating
+ Thermal + Transients Active components will be quallfled f or operability on a component by component basis in accordance with Reference 12, PSAR Section 1.6.
ASME Class 1 Component Supports will be designed and analyzed to the rules and requirements of ASPE Section ill Subsection NF.
The methods f or analysis and associated allowable limits that are used in the evaluation of linean supports f or f aulted conditions are those defined in ASME Section 111 Appendix F.
The load combinations for ASME Class 1 Component Supports are given in Table 3.9-5a for normal, upset, emergency and f aulted plant conditions.
i k h) 3.9-3a Amend. 75 Jan.1983
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The design of bolts f or ASNE Class 1 Component Supports for normal and upset plant conditions will be in accordance with paragraph NF-3280 of ASME Section lli Subsection NF.
For emergency and f aulted plant conditions, bolts will be treated as linear supports, and the methods for analysis and associated allowable limits are those defined in paragraph NF-3230, Subsection NF and paragraph F-1370, Appendix F of ASME Section 111.
l 3.9.2 ASME Code Class 2 and 3 Comoonents and Comoonent Suecorts 3.9.2.1 Comnenent Ooeratino Conditions and Desion Leadino Combinations Design pressure, temperature, and other loading conditions that provide the design basis f or fluid system Code Class 2 and 3 components are described in Appendix B of this PSAR and referenced in the sections that describe the system f unctional requirements.
3.9.2.2 Deslan Loadino Combinations Design loading combinations f or ASME Code Class 2 and 3 components, and piping, are given in Appendix 3.7-A which are the same as for Class 1 components.
Corresponding stress and pressure limits for each case are speci f ied i n Section 3.9.2.3.
For ASNE Section lli Class 2 and 3 components which are not sodium-containing and high temperature, the CRBRP will fully conform with the requirements of ASME Section lli Code. The load combination given in Appendix 3.7-A plus the additional load combination given below will be ut!!! zed.
I Normal and Emergency Conditions: Dead + Live + Operating + Thermal +
I Transients ASME Class 2 and 3 Component Supports will be designed and analyzed to the The methods for rules and requirements of ASME Section 111 Subsection NF.
analyst s and associated allowable limits that are used in the evaluation of linear supports f or f aulted conditions are those defined in ASME Section lli Appendix F.
The load combinations f or ASbE Class 2 and 3 Component Supports are given in Table 3.9-5a f or normal, upset, emergency and f aulted plant conditions.
The design of bolts f or ASME Class 2 and 3 Component Supports for normal and l
upset plant conditions will be in accordance with paragraph NF-3280 of ASME I
Section ill Subsection NF.
For emergency and f aulted plant conditions, bolts will be treated as linear supports, and the methods for analysis and l
associated allowable limits are those defined in paragraph NF-3230, Subsection NF and paragraph F-1370, Appendix F of ASME Section li t.
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3.9-3b Amend. 75 l
J an. 1983
a Table 3.9-5a Load Combinations for A$ME Class 1, 2 and 3 Component Supports System Ooerating Condition Load Combination Normal Weight + Thermal + Transients Weight + Thermal + Transients (1)
Upset
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+ WE Emergency Weight + Thermal + Transients
+ DSL(2)
Faulted.
Weight + Thermal + Transients
+ DSL(3) + SSE (1)
Seme as f ootnote (1), Page 3.7-A.16(a)
(2) includes only those dynamic system loadings associated with sodium water reactions (3) Dynamic system loadings associated with IHTS design basis leaks and water / steam rupture events.
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t 3.9-9ba Amend. 75 J an. 1983