ML19345H313
| ML19345H313 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 05/13/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19345H308 | List: |
| References | |
| NUDOCS 8105200093 | |
| Download: ML19345H313 (7) | |
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REQUEST FOR ADDITIONAL INFORMATION 251.0 Material Engineering Branch - Component Integrity Section 251.1 Demonstrate that the fracture toughness of all reactor coolant pressure boundary base metal, heat-affected zones and welds comply with the fracture toughness requirements of paragraph IV.A.1 of Appendix G.
To demonstrate compliance, provide the following information:
A.
Base Metals 1.
Supply fracture toughnsis data for ferritic pressure retaining materials used in surge nozzle forgings, pump covers, valve bonnets, lower control' element drive mechanism housings and upper control element drive mechanism housings that are limiting for operation per Appendix G of the ASME Code.
If fracture toughness data from these Waterford 3 ferritic materials dre unavailable, and the material is limiting for operation, the applicant may demonstrate the fracture toughness of the materials by supplying CVN impact data and drop weight data from sample materials which were procured to the same specification and thermomechanical treatment as the Waterford 3 RCPB material.
Sufficient data must be supplied to conservatively demonstrate that paragraph IV. A.1 fracture toughness requirements are met. The data submitted shal' include the following:
a) material specification of sample material and Waterford 3 RCPB material b) thermomachanical history of sample material and Waterford 3 RCPB material c) heat or lot of sample material and Waterford 3 RCPB material
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d) fracture toughness values of sample material l
l e) test temperature of sample material i
2.
For all primary side ferritic steam generator materials and all RCPB piping greatar than 2-1/2 inches thick, the applicant must submit drop weight test data or supply technical justification to demonstrate that the.VN impact data submitted in the FSAR is sufficiently e
conservative to determine the RT without the drop weight test NDT data.
3.
Three methods were used for estimating the RT for RCPB plates and forgingswhichhadlongitudinalCVNimpactab$0[ptionenergyvalues greater than 30 ft-lbs.
Provide CVN impact data from a sufficient number of heats-to demonstrate that the correlations used in these methods are convervative.
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9 4.
Generic curveswere used for estimating the RT for RCPB plates which had longitudinal CVN impact absorption N rgy values less than 30 ft-Ibs. The generic curves were developed based on CVN imoact data from San Onofre material.
Provide heat treatment inforaation from San Onofre mate.'fal and Waterford 3 material to demonstrate that the materials which form the basis for the generic curves, Figures 5.2-29 and 5.2-30, are metallurgically equivalent to the Waterford 3 materials.
B.
RCPB Heat-Affected Zones Outside the RV Beltline Region 1.
Provids CVN impact data for all RCPB heat-affected zones a) in the RV which were not fabricated using submerged arc or covered electrode weld processes; and b) outside the RV which were not fabricated using submerged arc or covered electrode weld processes and are limiting for RV operation.
2.
If the CVN impact data in B.1 cannot be provided, estimate the RT NOT from samples which duplicate the RCPB heat affected zones.
The samples' base material must be bricated from material that has been procured to the same spec 1rication as the Waterford 3 material and heat treated to the same requirements as the Waterford 3 material.
The sample's weld metal shall be produced using the same process, post weld heat treatment, electrode type, flux type and weld manufacturer as the Waterford 3 weld.
C.
For Weld Metals Inside the RV Beltline Region 1.
Provide CVN impact curves for each beltline weld.
2.
If sample material cannot be provided to the requirements of paragraph III.C.2 of Appendix G, provide:
a)
CVN impact test curves from samples which were produced using the same process, post weld heat treatment, electrode type, flux type and weld manufacturer as the Waterford 3 RV beltlint.
Sufficient CVN impact test data must be provided to assure the data is a conservative representation of the RV beltline weld, b)
CVN impact test data for RV beltline weld materials from each weld metal test per paragraph NB-2400 of the ASME Code.
D.
For each weld adjacent to a nozzle, a flange and a shell region near a geometric discontinuity in the RV indicate the RT and the method for determining the RT IfthemethodfordetermibgtheRT is differentthanthabe.quiredbyparagraphIV.A.1ofAppendix"kprovide data to demonstrate that the method is conservative.
E.
For RCPB welds outside the RV indicate the RT of the welds that are limiting for operation.
Indicate the method b determining the RT II NOT' 2
f the method for determining the RT is different than that required by paragraph IV. A.1 of Appendix G, pbide data to demonstrate that the method is conservative.
251.2 Provide the time interval for calibration of testing and measuring equipment used in the impact testing of reactor vessel, steam generator, pressurizer, and reactor coolant pump materials.
If the above information cannot be provided or if the information provided does not comply with the calibration interval of paragraph NB-2360 of the ASME Code, state why the information cannot be provided and identify why the method used for celibrating l
the equipment is equivalent to + hose of paragraph III.B.4 of Appendix G, 10 CFR Part 50.
251.3 Provide a conservative demonstration that RCPS nuts fabricated from SA-194 Gr.87 and SA-193 Gr.87 material when tested at 60 F will meet the following JVN requirements:
a) 25 miis hteral expansion for bolitng over one inch thru four inches in nominal diameter.
b) 25 mil lateral expansion and 45 ft-lbs absorbed energy for bolting over four inches in nominal diameter.
Lower bound CVN curves for SA-194 Gr.87 and SA-193 Gr.87 are considered acceptable methods for extrapolating the CVN impact data from the test tempera-ture to 60 F.
In addition, demonstrate that the metallurgical condition of material used to generate the lower bound curves for SA-194 Gr.87 and SA-193 Gr.87 material are equivalent to the metallurgical condition of the Waterford 3 i
nuts fabricated from SA-194 Gr.B7 and SA-193 Gr.B7 material.
This can be l
accomplished by providing the heat treatment information for the material L.d to generate the lower bound curves and the Waterford 3 nuts.
251.4 Demonstrate that the metallurgical condtion of the materials used to t
generate the lower bound curve, FSAR Figures 121.3-1 and 121.3-2 are equivalent to the metallurgical condition of the Waterford 3 RCP casing studs and RV bolting (heat no. 18551).
This can be accomplished by providing the heat treatment information for the material used to generate the lower bound curves and for the Waterford 3 RCP casing studs and RV bolting (heat no. 18551).
251.5 There are many incon:.stencies in the Charpy test data as shown in Figures 5.3.2 through 5.3.4, and the corresponding fracture toughness data l
reported in Table 5.2-6 and Table 5.3-3 of the Waterford FSAR.
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a)
Reexamine the fracture toughness data and either correct or explain the inconsistencies in CVN data reported in Table 5.3-3 and the CVN data plotted in Figures 5.3-2, 5.3-3 and 5.3-4.
b)
The applicant must reexamine the fracture toughness data in Tables 5.2-6 and 5.3-3 and explain the inconsistencies in the data.
Table 5.3-3 indicated that longitudinally oriented CVN specimens are more brittle than transversely oriented CVN specimens from M-1004-2 base metal.
c)
Provide the transverse base meta. CVN impact curves which form the basis for the transverse CVN data presented in Table 5.3-3.
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251.6 Reexamine the pressure temperature limit curves in the FSAR to explain or to correct the curves which indicate that the heatup curves are more limiting than the cooldown curves. Thermal stresses should cause the cooldown curves to be more limiting than the heatup curves.
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l LOUISIANA POWER AND LIGHT COMPANY WATERFORD STEAM ELECTRIC STATION, UNIT 3 REQUEST FOR ADDITIONAL INFORMATION MATERIALS ENGINEERING BRANCH DIVISION OF ENGINEERING 251. '7 Identify the specific model (s) of Westinghouse low pressure turbine (s) installed in Waterford SES Unit 3.
Provide tables showing, for each of the unique 'vheels in a Waterford low pressure turbine, the weight and location of the wheels relative to the turbine center, and the a) dimensions, b) shapes, c) weights and d) initial energy (or velocity) ranges of missiles postulated to be representative of missile-producing turbine wheel rupture at 1.
design overspeed, and
- 11. destructive overspeed.
Show how values for the exit energies are obtained or reference an available document which contains an adequate description.
251. 8 Provide tables listing, in detail, all barriers and safety related targets considered in the calculation of P (or P X P ).
Previde schematic 2
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drawings (to scale) which sh w the location and orientation of barriers and targets relative to the turbine train. The targets should be specific components (e.g. steam generators 1 & 2, reactor vessel, feedwater lines, main steam lines, auxilliary feedwater pt.mps 1 & ?, etc.)
251 S The discussion of high trajectory turbine missiles presented in 3.S.1.3.3 of the FSAR needs clarification.
If the prz,edure used to obtain P~is that 2
approved in Standard Review Plan Section 3.5.1.3, it should be so stated.
. If some other procedure is followed, as appears to be the case, the derivation of the probability formulas used must be presented for review and approval by the NRC staff.
251. 10 The defin.'tions of the variables in 3. 5.1. 3. 3.1 of the FSAR do not agree with those presented in Appendix 3.5A.
The former, however, represent the conventional breakdown of the damage probability.
Show the formulas or constants which constitute quantitative definitions of the probabilities presented in 3.5.1.3.3.1, and describe how they are used.
The values of P shown in 3.5.1.3.3.2 are unacceptable; the values 1
currently accepted by the NRC staff are 6 X 10-5 and 4 X 10-5 per turbine year for design and destructive overspeed failv es, respectively.
There is no description in the FSAR of the method used to calculate P 2
for low trajectory missiles. The probability P must either be derived 2
or an available document referenced which contains an adequate derivation.
To be conservative, and due to lack of infomation, the values of P 3
are generally taken to be one.
If other values are used, the appropriate equations must be derived and the values obtained for each target must be l
justified to the NRC staff.
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251.11 The equation 3a in 3.5.1.3.3.J of the FSAR is not the correct definition l
of the NDRC " perforation thickness." Consequently, calculations and discussions steming from the use of equation 3a are erroneous.
Equation t
3a and subsequent discussions in 3.5.1.3.3.3 and 3.5.1.3.3.4 must be corrected.
Note, the perforation thickness is generally used to determine barrier effectiveness in the calculation of P, and not in the determination of the 2
l target damage per strike probability P.
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251 12 Re-calculate the P XP probabilities associated with each safety 2
3 related target for design overspeed, and destructive overspeed, and show that the total P XP for each of these failure conditions 2
3 it. less than 10-3 per failure, as stipulated in Regulatory Guide 1.!15.
Prepare a table showing the P XP probabilities for each target.
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