ML20073N044
| ML20073N044 | |
| Person / Time | |
|---|---|
| Site: | 05000605 |
| Issue date: | 05/10/1991 |
| From: | Marriott P GENERAL ELECTRIC CO. |
| To: | Chris Miller NRC, NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| EEN-9139, MFN-050-91, MFN-50-91, NUDOCS 9105160128 | |
| Download: ML20073N044 (12) | |
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i GE Nuclear Encryy hiav 10,1991
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hiFN No. 050 91 Docket No. CTN 50-605 ElIN 9139 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention:
Charles 1.. hiiller, Director Standardization and Non Power Reactor Project Directorate
Subject:
GE Responses to Gli/NRC h1aterials & Chemical Engineering liranch Conference Call of Aprii 30,1991 Enclosed are thirty four (34) copies of the GE responses to the discussion items of the subject call.
It is intended that GE willincorporate these responses in a future amendment.
Sincerely,
)
/
P. W. hlarriott, hianager Regulatory and Analysis Services h1/C 382, (408) 925-6948 cc:
F. A. Ross (DOE)
D. C. Scaletti (NRC)
J. G. Spraul (NRC)
J. F. Quirk (GE) o 9105160128 910510 PDR ADOCK 05000605 g
n PDR gi l\\
/
RESPONSES TO MATERIALS & CllEMICAL ENGIllEERING DISCUSSION ITEMS DISCUSSION ITEli_1 Section 10.2.3.1 Material Selection The staff recommends the following SRP 10.2.2.11.1 critoria bo included in this section The fracturo appearance transition temperaturo (50% FATT) as obtained from Charpy tests performed in accordance with specification ASTM A-370 should be no higher than O
for low-pressure turbine disks.
The Charpy V-notch energy at the minimum operating-temperature of each low-pressure disk in the tangential direction should be at least 60 ft-1b.v.
PESPOllSE 1 See revised Section 10.2.3.1 attached.
DISCUSSION ITEM 2 Section 10.2.3.2 Fracturo Toughness The applicant should clarify whether 115% of rated speed is the design overspoed for the low pressure turbine.
The third paragraph in the section should include the following:
Sufficient warnup tirao should be specified in the turbine operating instruction to assure that toughness will be adequate to prevent brittle fracture during startup.
SRP 10.2.3.11.2 recommends 4 acceptable methods to obtain fracture toughness proporties.
The spplicant discussed one of the methods (mothod C) that was presented by J.A.
Begioy and W.A.
Logsdon in Westinghouse Scientific Paper 71-1E7-MSLRF-Pl.
j liowever, the applicant should stato that this method of obtaining i
fracture toughness, KIC, should be used-only on materials which exhibit a well-defined Charpy onergy and fracture appearance i
transition curvo and are strain-rate inconsitive.
The test data
-and the calculated toughness curve should'be submitted to the NRC i
staff for review.
l RESPONSE 2 1
-See revised Section 10.2.3.2 attached.
l i
L.
- _ - -, ~...... -
DISGESIoli ITIM_1 Section 10. 2. 3. 3 liigh Temperature Properties Provide specific ASTM sections that were referenced in this section.
RESPOllSP 3 Reference 2 was added to Section 10.2.3.3 and to revised Section 10.2.6 attached.
DlfLCUSSIO!1 ITEM 4 Section 10.2.3.4 Turbine Design The following SRP 10.2.3 criteria should be included in this sections a.
The design overspeed of the turbine should be 51 above the highest anticipated speed resulting from a loss of load.
The basis for the assumed design overspeed should be submitted to the staff for review.
- b. The combined stresses of low-pressure turbine disk at design overspeed due to centrifugal forces, interference fit, and thermal gradients should not exceed 0.75 of the minimum specified yield strength in the weak direction of the materials if appropriate tensile tests have been performed on the actual disk material.
c.
The turbine disk design should facilitate inservice inspection of all high stress regions, including bores and keyways, without the need fro removing the disks from ti shaft (if shrunk-on disk rotors were used).
The applicant should clarify whether the low pressure turbines will have shrunk-on disks, welded disks, or forged disks.
EEELQESfel See revised Section 10.2.3.4 and new Section 10.2.5.2 attached.
ELECVSSION ITEM 5 Section 10.2.3.6 Inservice Inspection SRP 10.2.3.5 recommends and the applicant commits to inservice inspection for the turbine disks at about 10-year intervals.
However, in recent years, the staff has required applicants and licensees to use a probabilistic approach for scheduling the inspection of the low pressure turbine rotors with shrunk-on disks (NUREG-1048, " Safety Evaluation Report Related to the Operation of Hope Creek Generating Station Supplement No.
6," July 1986).
The turbine inspection program in the Hope Creek Generating Station is based on the General Electric Company proprietary report titled " Probability of Missile Generation in General Electric Nuc1 car Turbines", January 1984.
This methodology has been reviewed by the NRC staff and found acceptable for use in establishing maintenance and inspection schedules for specific turbine systems.
The intent of the program evaluated in NUREG-1048 is to ensure thattheprobabglityofturbinemissilegenerationismaintained lessghat1x10-per year for an unfavorably oriented turbine and 1x10-per year for a favorably oriented turbino.
The program takes into account specific turbine rotor operating conditions, material proporties, results of periodic in-service inspections, and other factors.
The program's determination of missile probability is based on the probabilities of individual parameters which may lead to the generation of the turbine missile.
As a result, the program can facilitate ovaluations of the effects of changes in any parameter.
The probability of unacceptable damage from tugbine missile should be maintained at less than or equal to 1x10-per year.
Schedules for future inspection and replacement of low-pressure turbine rotors with shrunk-on discs should be baced on the probabilistic approach.
RESPONSE 5 See item (6) of revised Section 10.2.3.4 attached.
'ABWR nA61MAC Standard Plant n,v c Table 1.91 i
SUMMARY
OF ABWR STANDARD PLAhT lhTERFACES WITH REMAINDER OF PIANT (Continued)
TTE M INTT.RFACE h 0.
SUBJECT TYPE SUBSECTION 8.11 DC Voltage Analpls Confirtnatory 83.4.6 8.12 Seismic Oualification of Eyewash Equipment Confirmatory 8.3.4.7 8.13 Diesel Generstor Lead Table Changes Confirmatory 83.4.8 8.14 Offsite Power Supply Anangements Procedural 83.4.9 8.15 Diesel Generator Qualification Tests Confirmatory 8 3.4.10 8.16 Defective Refurbished Circuit Breakers Confirmatory 8 3.4.11 8.17 Miitimum Starting Voltages for Class Confirmatory 8 3.4.12 1E Motors 9.1 New Fuel Storage Racks Criticality Analpis Confirmatory 9.1.6.1 9.2 New Fuel Storage Racks Dynamic and Impact Confirmatory 9.1.6.2 Analysis 93 Spent Fuel Storage Racks Criticality Analysis Confirmatory 9.1.63 9.4 Spent Fuel Storage Rack Load Drop Analysis Confirmatory 9.1.6.4 9.5 Ultimate heat sink capability Design 9.2.17.1 9.6 Makeup water system capability Design 9.2.17.2 9.7 Potable and Sanitary Water System Design 9.2.17.3 9.8 Radioactive Drain Transfer System Collection Design 9 3.12.1 Piping 9.9 Contamination of DG Combustion Air intake Confirmatory 9.5.13.1 9.10 Use of Communication System in Emergencies Procedural 9.5.13.2 9.11 Maintenance and Testing Procedures for
- Procedural 9.5.13 3 Communication Equipment 9.12 Fire Hazard Analysis Database Confirmatory 9A.63 to.t Low Prossure. h hvM. Ossk c ov$cv.* beg n0.2.5.)
r e-n eA w w-4 Toq b eer I O ' E I' 1 10.2.
w r6 n e. Dess y. overs pe.d D** P 1.95 Amendmeat 15 I
AISWR nxnow Staglan! I'lant en A CilAPTEll 10 TAllLE OF CONTENTS l
Section Illig l' age 10 STEAM AND POWElt CONVEllSION SYSTEM 10.1 EUS1$1 ARY DESCRilTION 10.1 1 10.1.1 Protective Teatures 10.1 2 1
10.2 TURillNE Gl:NERATOR 10.2 1 l
10.2.1 Design Ilases 10.2 1 10.2.2 Description 10.2 2 10.2 3 Turbine Disk integrity 10.2 6 10.2.4 Evaluation 10.2 8 to 2.5 I 4* v IV ee 5 10.24 G.
References 10.2 9 103 51 AlN STEet St'PPIN 10 3.1 Design Bases 103 1 1
103.2 Description 103 2 1033 Evaluation 103 4 103.4 Inspection and Testing j
Requirements 103 5 103.5 Water Chemistry (PWR) 103 5 103.6 Steam and Feedwater System hlaterials 103 5 10.4 0111ER FE ATURES OF Tile STE A51 AND POWER CONVERSION SYSTES1 10.4.1 hiain Condensers 10.4-1 10.4.2 hiain Condenser Evacuation System 10.4-4 10.4 3 Turbine Gland Scaling System 10.4-5 10 ii Amendment 3
ABWR 234anw fitjulditrd Plant r~ s SECTION 10.2 CONTENTS (Continued)
Section Tilk bge 10.2.3.6 Inservice Inspection 10.2 7 10.2.4 littluntion 10.2 8
)
10.2 / 6 Feferences 10.2 9 i
TAllLES 1alde Title hge l
10.2 1 Events Following Loss of Turbine Load with Postulated Equipment Failures 10.2 10 l
1LLUSTRATIONS Deures Illk bge 10.2 1 Turbine Stop Valve Closure Characteristic 10.2 11 10.2 2 Turbine Control Valve Fast Closure Characteristic 10.2-12 10.2 3 Acceptable Range for Control Valve Normal
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Closure Motion 10.213 10.2-4 Generator 11ydrogen and CO System Diagram 10.2 14 2
~1&de a ce s i O. 2. 5.
t o. 2,5 1 Low Pra.ssu s 7 uv 6,-e D$s(
p m (-N - e "To q \\ wa3#
40,7.5.1 h\\em t De sip, Ov er s p46d 10.2 ui Amendment 3
i 2
23A61e0AJ m... i Standard Plant i
l(5) Bearing metal and oil drain temperatures (7) 'nirust bearing wear detector l
l l (6) Shell temperature (8) Remote trip solenoids l
i l
l (7) Valve positions (9) Lubricating oil pumpe l
d l (8) Shell and rotor differential espansion (10) Control Guid pumps l
l l (9) Shaft speed, electrical load, and contro1 valw 10.2J Turbinelategrity l
l.
lalet pressure ladication 10JJ.1 Materials Selecties 4
l l (10) Hydrogen temperatwe, pressure, and purity Turbine rotors and parts are made from vacunni l
meked or vacuum desassed Ni Cr.Mo V alloy steel j
l (11) Stator coolant temperature and conductivity by processes which minimize flaw occurrence and j
l (12) Stator windingtemperatwo provide adequate fracture toughness. Tramp ele.
meats are controlled to the lowest praaical conces.
l trations consistent with good scrap selection sad l (13) Enciter air temperatwas melting practice, and consistent with obtaining adequate laitial and long life fracture toughness for 3
l (14) Turbine gla al sealing prusure the environment la which the parts operate. The- --
turbine materials have the lowest fracture appearance
(
l (15) Gland sica a condenser vacuum transition temperatures (FATT) and higbast Charpy
.l V.aotch energies obtainable, os a consistent basis, j
l (16) Steam ches' pressure from water quenched Ni Cr.Mo V material at the j
slaes and strength levels used. Slace actual levels of l (17) Sealoilpressure FATT and Charpy V. notch energy vary depending 4
l 10JJ.7 Teotias upon the slas of the part, and the location withis the part, etc., these variations are taken into account la l
accepting specific for$ ass for use la turbines for l
j The electrical and mechaalcal overspeed trip devices can be tested remotely at rated speed, under nuclear applicatio_a/Ciarpy tests ~tre perrorme l
load, by means of lighted pushbuttons on the EHC essentially la accordance with Specification ASTM l
test panel. Operation of the overspeed protection A 370.
devices under controlled, overspeed condition is
( m a p.7 l
checked at startup and after each refueling or asshe 1323J FreetareTenghases go,o 3.t l
maintenance outage.
Sultable material tousbaens is obtained through
[
the use of selected materials as described la Subsec.
Provisions for testing each of the following l
devices while the unit is operating are lacluded:
tion 10.2.3.1, to produce a balance of adequate material strength and toughness ;o ensure safety while
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simultaseously providing high reliability, availabihty, i
l (1) Mais stop and control valves efficiency, etc. during operation.
l (2) Turbine bypass' alves v
heress calculations include components due to l (3) Low pressure turbine combined latermediate centrifugal loads, laterference fit, and thermal valves (CIVs) gradicats where applicable. The ratio of material i
fracture toughness, Km (as derived from material l-l (4) Overspeed governor tests on each major paWor rotor), to the maximum tangential stress at speeds from normal to 115% of l
l (5) Turbine entraction aoaretura valves rated speed (the highest anticipated speed result from a loss of load is 110%)is at least 2 inc.
l(6) Coadcaser vacuum trip system Adequate material feeurs toughness needed to main-tala this ratio la assured by destructive tests on l
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ABWR moom Standard Plant bA material s.mples using correlation methods which (1) Forgings are rough machined with minimum l are as conservative, or more so, than those presented stock allowance prior to heat treatment, h
in Reference 1. *-iw sskT i 0. 2
- 9. 2. a (2) Each finished machined rotor is subjected to l Turbine operating procedures are employed to 100 percect volume:ric (ultrasonic), and surface preclude brittle facture at startup by ensuring that visual examinations, using established metal temperatures are (a) adequately abose the acceptance criteria. These criteria are more FATT, and (b) as defined above, sufficient to main-restrictive than those specified for Class 1 tain the fracture toughness to tangential stress ratio components in the AShlE Boiler and Pressure at or above 2 / inch. - i w sm s o. 2 's z b Venel Code, Sections ill and V, and include the requirement that subsurface sonic indications 10.23J liigh Temperature Properties are either removed or evaluated to ensure that they will not grow to a sire which will The operating temperatures of tbc high pres-compromise the integrity of the unit during its sure rotors are below the stress rupture range.
senice life.
Therefore, creep-rupture is not considered a signifi-
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cant failure mechanism.
(3) All finished machined surfaces are subjected to l
3 magnetic particle test with no f'tw indications Basic stress and creep rupture data are perminible, obtained in standarrllaboratory tests at appropriate temperatures with equipment and procedures (4) Each fully bucketed turbine :
assembly is l
consp' tent with ASThi recommendationsq spin tested at 20 percent overspe.4 m
R 4 t e ve n u 2..
10.23.4 Turbine Design Additional preservice inspections include air leakage tests performed to determine that the The turbine assembly is designed to withstand hydrogen cooling system is tight before hydrogen is normal conditions and anticipated transients, includ-introduced into the generator easing. The bydrogen ing those resuhing in turbine trip, without loss of purity is tested in the generator after bydrogen has structuralintegrity. The design of the turbine been introduced. The generator windings and all assembly meets the foUowing criteria:
motors are megger tested. Vibration tests are performed on all motor driven equipment. Hydro-l (1) Turbine shaft bearings are designed to retain static tests are performed on all coolers. All piping is their situctural integrity under normal pressure tested for leaks. biotor operated valves are operating loads and anticipated transients, factory leak tested and inplace tested once installed.
Including those leading to turbine trips.
10.23.6 Inservice lospection l(2) The multitude of natural cri;lcal frequencies of the turbine shaft assemblies existing between The insenice inspection program for the turbine zero speed and 20 percent overspeed are assembly includes the disassembly of the turbine and controlled in the design and operation so as to complete inspection of all normally inaccessible parts, cause no distress to the unit during operation.
such as couplings, coupling bolts, turbine sbaIts, low pressure turbine buckets, low pressure and l(3) The rnaximum tangential stress resuhing from high pressure rotors. During plant shutdown centrifugal forces, interference fit, and thermal coinciding with the insenice inspection schedule for gradients does not exceed 0.75 of the yield ash 1E Section 111 components, as required by the strength of the materials at 115 percent of rated AShiE Boiler and Pressure Vessel Code,Section XI, g 3 p, r speed.
turbine inspection is performed in sections during the
--+
io,e.3.4 refueling outages so that in 10 years total inspection g4g 10.2JJ Presenice inspection has been completed at least once.
The presenice procedures and acceptance crl-This inspection consists of visual and surface teria are as follows:
examinations as indicated below:
Amendment 8 10.2-7 J
AInVR 2mu,w Standard Plant n,.
3 Since there is no nuclear safety related mechani-cal equipment in the turbine area and since the condenser is at subatmnspheric pressure during all modes of turbine operation, failure of the joint will have no adverse effects on nuclear safety related equipment.
tuss 9T 10.25 References 1.
J. A. Begley and W. A. Legsdon, Westinghouse Scientific Paper 711E7 MSLRF Pl.
- 2. A S T M S e c-h ow LIE, Vo l O '3. on, E t 3 9 - 6 3 SdG ud a d Pra ch e< Our Co w ducM og Cr erp; Cro p Rw pba a.w el S k sa R u w ha d Yt t hJ N fko k kiC. M c4 C%taki o
Amendment 3 10.2 9
INSERTS INSERT 10.2.3.1 The fracture appearance transition temperature (50% FATT) ad G*)
obtained from Charpy tests performed in accordance with specification ASTM A-170 will be no higher than OOP for low-pressure turbine disks.
The Charpy V-notch energy at the minimum operating temperature of each low-pressure disk in the tangential direction should be at least 60 ft-lbs.
INSERT 10.2.3.2a However, this method of obtaining fracture toughness, K Will IC+
be used only on materials which exhibit a well-defined Charpy
~
energy and fracture appearance transition curve and strain-rate insensitive.
The applicant referencing the ABWR design will provide the test data and the calculated toughness curve to the NRC staff for review. (See Subsection 10.2.5.1 for interface requirements)
INSERT 10.2.3.2b Sufficient warmup time should be specified in the turbine operating instruction to assure that toughness will be adequate to prevent brittle fracture during startup.
INSERT 10.2.3.4 (4)
-The design overspeed of the turbine will be 5% above the highest anticipated speed resulting from a loss of load.
The basis for the assumed design overspeed will be submitted to the MCR staff for review.
(See Subsection 10.2.5.2 for interface requirenients)
(5)
The combined stresses of low-pressure turbine disk at design overspeed due to centrifugal forces, interference fit and thermal gradients will not exceed 0.75 of the mirimum specified yield hh strength of the material, or 0.75 of the measured yield strength in the weak direction of the materials if appropriate tensile tests have been performed on the actual disk material.
(6)
The turbine disk design will facilitate inservice inspection of all high stress regions, including bores and keyways.
The turbine rotor design will be a solid forged monoblock rotor rather than shrunk-on disks.
l
A i
INSERT 10.2.5 1
1 10.2.5 Interfaces 1
10.2.5.1 Low Pressure Turbine Disk Fracture Toughness m
i The applicant referencing the ABWR design will provide turbine
] (b) material property drita and ar~ure sufficient turbine warmup time j
as required by Subsection 10.2.3.2, 1
10.2.5.2 Turbine Design Overspeed i
The applicant referencing the ABWR design will provide-the basis
([)
for the turbine design overspeed as required by subsection i
10.2.3.4(4).
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