ML20198E436
| ML20198E436 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/30/1997 |
| From: | Schopfer D SARGENT & LUNDY, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 9583-100, NUDOCS 9801090096 | |
| Download: ML20198E436 (14) | |
Text
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Do's K. Schopitt
- Vice President '
- 312 269-6078 December 30,-1997 Project No.' 9583-100.
Docket No. 50-423 Northeast Nuclear Energy Company
- Millstone Nuclear Power Station Unit 3 Independent Corrective Action Verification Program i United States Nuclear Regulatory Commission
- Attention: Document Control Desk Washington, D. C. 20555 -
In accordance with Subsection 4.3a of the Independent Corrective Action Verification Program (ICAVP) Audit Plan, Revision 3, this letter requests the Nuclear Regulatory Commission's (NRC) approval for sampling some calculation types for the Tier 1-systems. Specifically, this letter addresses sampling of the following calculations:
s-MOV calculations for the Service Water (SWP) and the Quench Spray (QSS)/ Containment Recirculation (RSS) systems.
- Pipe support calculations for the HVAC (HVX) and Diesel Generator (DGX) systems.
- * - Duct and Duct support qualification calculations for the HVX systems.
. Conduit and Cable Tray support calculations for all Tier 1 systems.
Calculations for stmetural components of the HVX & DGX systems.
- L Pipe stress calculations for the HVX and DGX systems.
- The proposed sample size as well as'the technical basis for the proposed sample size are presented 7
in Attachments A'through F, respectively. The proposed sampling criteria described in these 1
- attachments is consistent with the sampling criteria described in our August 5,1997 letter for the
- QSS, RSS and SWP pipe stress and pipe support calculations, which was approved by the NRC.
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- ff 9001090096 971230 e
PDR ADOCK 05000423 I
P pop 4
55 East Monroe Street
- Chicago, IL 60603 5780 USA 312-269-2000
y i Document Control Desk Project No. 9583-100 Page 2 :
- In addition to the above we are requesting approval to apply the above~ pipe stress'and support -
calculation sampling criteria to the review of the calculations prepared for the recently completed RSS system modifications.' These modifications include DCR M3-96054, -96056, -96062, --
97042, 97045, -97063, 97580 and -97094. We believe siampling of the stress and support calculations for these modifications in conjunction with the sampling of existing pipe stress and..
support calculations that was already performed as part of the.RSS Tier 1 system' review will provide the necessary level of review.
In summary, we believe the_ proposed sampfhg will provide the level of review necessary to ensure the selected Tier i systems are capable of performing their functional requirements and that the design of the systems is consistent with the design and licensing basis as required by the confirmatory order, This conclusion is based on the following:
- The proposed sampling only affects those calculations or calculation stepr. that are repetitive in nature.
1 The proposed sample size, where applicable, covers a sufficient number of the repetitive type calculations, such that a determination can be made as to the integrity of the repetitive type calculations, and the calculation process. If errors are identified which indicate potential process problems, expansion of the sample size may be increased by the NRC.
The proposed samp!ing is consistent with the NRC's Oversight Inspection Plan which states e
that the inspection methodology for the ICAVP shall be similar to inspections described in inspection procedures 93801, Safety System Functional Inspections, and NC-2530, Integrated Design Inspection Program.
Both of these inspection procedures allow selection of appropriate inspection samples.
We are proceeding with the twiew based on the proposed sample sizes. You may direct any i
. questions to me at (312) 269-6078.
Yours very tmly, p
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D.K.S pfer
-Vice President and ICAVP Manager DKS:AAN:spr -
Copies:
E. Imbro (1/4) Deputy Director, ICAVP Oversight Ti Concannon (1/2) Nuclear Energy Advisory Council J. Fougere (1/3)NU
'B. A. Erler (1/0)
MAICAVPLOhpCore97WR0f054 doc I
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i Attachment A-Page 1 of 2 j
- A.
MOV CALCULATIONS A.1-Background -
There are a total of 38 motor operated valves associated with the Tier 1 systems in the -
scope of the Generic Letter 89-10 program (14 RSS,2 QSS_and 22 SWP). Since many
-valves are identical for parallel trains, the total population of unique valves is 12 (e.g.
3RSS*MOV 20A, B, C and D are allidentical.).
A. 2..
Design Basis (System) Calculation The syMem calculations determine the operating conditions for each valve. This includes
. the differential pressure and flows.
There are three calculations for the Tier i systems; one calculation for each system (SWP,
- QSS & RSS). All three calculations will be included in the scope of review.
1
-. A.3 Methodology Calculation rThe methodology calculation provides general information for performing the va ve I
calculations. This includes the definitions, general references, etc. This is a generic calculation applicable to all MOVs in the program. This calculation will be included in the scope of review.
A.4 '
Thmst/ Torque The calculatic.is provide the following information:
L target window thrust / torque limits b
maximum torque switch setting diagnostic equipment input data non.as-left not to exceed test limits whether the MOV is limited in cycles close valve factor capability control scheme stall damage evaluation results (when required).
1 There are a total of twelve calculations. F.ach valve group has a separate calculation l
except that valves 3RSS*MOV8837A/B and 8837A/B are combined into one calculation.
These calculations for each valve type (butterfly, gate and plug) are similar and repetitive.-
LWe propose to review one calculation for each of the three valve types.
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Attachment A Page 2 of 2 -
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A.5 Electrical:
The electrical calculations for the MOVs are similar for all types of MOVs. - The calculations determine the voltage and thermal overload for the motors.- These items are not based on the type ofvalve.
There are six calculations. Two calculations cover the SWP Valves which include butterfly and plug valves. One calculation covers the QSS & RSS butterfly valves. The remaining three calculations are for the RSS gate valves. We propose to review three -
calculations one for each valve type, even though the valve type does not affect the calculation methodology.
A.6 Weak Link These calculations determine the limiting operator torque values based on a structural weak link assessment. Each component of the valve, subject to the torque load, is analyzed, in combination with other design basis loads, to detennine the limiting torque
- which will not result in stresses exceeding the appropriate allowable stresses.
The critical components for each of the three valve types are the same; therefore the methodology for analysis for each valve type is the same. In addition, the types ofloading conditions for each valve type are the same. The only difference in the calculations for each valve type are dimensional and material differences and the magnitude of the loads.
There are ten calculations. One calculation covers plug valves. Two calculations cover gate valves. The remaining seven calculations cover butterfly valves. We propose to review three calculations, one for each valve type due to the repetitive nature of the calculation for a given valve type.
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Attachment B Page1of2 B.
PIPE SUPPORT CALCULATIONS B.1 Total Population The total population for nipe support and related calculations for DGX and HVX systems is as follows:
Type DGX-HVX Generie System System Master Support N/A N/A 3
Calculations Non-Standard 122 2
N/A Pipe Support Calculations Non Standard 129 20 N/A Tubing Support Calculations Standard Pipe 41 N/A N/A Support Calculations Standard Tubing 58 N/A N/A Support Calculations H.2
- Master Support Calculations The master support calculations contain reference documents utilized for the design assumptions, methodology and generic criteria for the design of steel members, plates, welded connections, ar.chors and local stresses in structural steel members. We propose 100% detailed review of these calculations.
H.3 Non-Standard Pipe Support Calculations These calculations contain the structural evaluation of auxiliary steel members and standard support components. We propose a 10% smart se.mple of these calculations.
The minimum size shall not be less than 3 for populations greater than 2 supports or 100%
- for population equal to or less than 2 supports.
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Attachment B[
Page 2 of 2
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A 10% sa'uple is deemed sufficient since these calculations are repetitive in nature and e-since the geueric design criteria and assumptions are contained in the r.uster calculatens --
which, as stated above, will receive a 100% review, The repetitive tasks _ include.
l transposing design loads from stress calculations, developing computer models, and _.
performing mathematical computations. The 10% sample of non-standard supports will--
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be selected as described below to ensure adequate diversification'of standard types (i.e...
struts, straps, snubbers, venical rod, clamps, guides, saddles, etc.) is achieved and that a
- sufficient number of cases with high stress conditions are selected.
. 1)
The total population of non-standard supports will be reviewed and grouped by the component type.
2)
Select 10% of the total population of each component. The minimum size of the sample shall not be less than three (3) for any population ~ greater than two
- supports.
3)
- Magnitude ofloads, thermal movemen:s resulting in additional friction loads and
- configuratiot, types will be reviewed to ensure that potentially highly stressed conditions are selected.
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B.4 Non-Standani Tubing Support Calculations -
These calculations contain the structural evaluation of auxiliary steel members and mechanical components. Using the same rationab as for item B.3, we propose a 10%
sample for these calculations.
B.5. - Standard Pipe Support Calculations These calculations contain the structural evaluation of auxiliary steel members and mechanical components, Using the same rationale as for item B.3, we propose a 10%
sample for these calculations.
- B.6 Standant Tubing Support Calculations These calculations contain the structural evaluation of auxiliary steel members and
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mechanical components. Using the same rationale as for item B.3, we propose a 10%
sample for these calculations.
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Attachment C Page 1 of 2 t
C.
DUCT AND DUCT SUPPORT CALCULATIONS C.1 Total Population The total population for duct qualification analysis and duct supports for DGX and HVX systems is as follows:
Type DdX HVX Generic Duct Qualification N/A 6
N/A Master N/A N/A 14 Non-Standard 84 503 N/A Duct Supports Standard Duct N/A 13 N/A Supports C.2 Duct Qualification Duct Qualification Calculations contain design assumptions, methodology and generic crite:ia for checking duct stresses. We propose 100% detailed resiew of these calculations.
C.3 Master Duct Support Calculations The master support calculations contain reference documents utilized for the design assumptions, methodology and generic criteria for the design of steel members, plates, welded connections, anchors and local stresses in structural steel members. We propose 100% detailed review of these calculations.
C.4 Non-Standard Duct Supports These calculations contain the structural evaluation of auxiliary steel members. We propose a IW. sample of these calculations. A 10% sample is deemed sufficient since these calculations are repetitive in nature and since the generic design criteria and
' assumptions are contained in the master calculations which, as stated above, will receive a 100% myiew. The repetitive tasks include transposing design loads from stress calculations, developing computer models, and performing mathematical computations.
The 10% sample of non-standard duct supports will be selected to ensure that a sufficient number ofcares with high stress conditions is selected.
Attachment C-Page 2 of 2.
C.5 Standard Duct Support Calculations These calculations contain the structural evaluation of auxiliary steel members generic details and are not repetitive in nature. Therefore, we propose 100% review of these calculations.
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Attachment D Page1of2
- b. -
CONDUIT AND TRAY SUPPORTS D.1 Total Population The total population for conduit and tray supports and related calculations for DGX and HVX systems is as follows:
Type Generie Conduit Supports 159 Type SWP QSS/RSS DGX HVX Generie-Tray 380 301 293 310 N/A Supports D.2 Conduit Supports These calculations contain the structural evaluation of auxiliary steel members. Condait Support configurations typically used at Millstone Station, Unit - 3 are based on standard i
conduit support details shown on BE 52 series ofdrawings that contain 159 support configurations. We propose 10% random sample selection for these calculations. The random selection criteria applied to large populations typically offers adequate assurance that review sample provides representation of population attributes. Also, inspection of BE-52 series of drawings and calculations ri.vealed repetitive nature of most of the calculations based on the similarity of the support configurations. Therefore, proposed calculation review methodology is expected to capture all relevant design aspects associated with typical support details.
D.3 Tray Supports These calculations contain the structura: evaluation of auxiliary steel members. Tray supports are typically attached to the large support frames with multiple tray support attachments. We propose a detailed review of one frame structure for each elevation within each building that contain cable tray associated with Tier 1-Wave I system cables.
Support frames will be selected at applicable elevations of the following buildings:
Containment Auxiliary ESF Service Control Fuel
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- Attachment D Page 2 of 2
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This type of the review is deemed sufficient to provide adequate representative sample and
. capture all relevant aspects of the design as related to the selection of seismic excitation coefficients, design load input, frame modeling and evaluation of stresses in auxiliary steel -
members and welded connections.
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Attachment E 7
Page1of1 E.
CALCULATIONS FOR STRUCTURAL COMPONENTS E.1 Embedded Plate Calculations These calculations contain evaluation of attachments to steel plates anchored to reinforced concrete structures. We propose review of attachments to umbedded plates as appbcable to the supports selected for the review sample addressed in Attachments B, C and D.
E.2 Structural Steel Calculations These calculations contain evaluations of attachments to in-place structural steel beams.
We propose review of attachments to structural steel as applicable to the supports selected for the review sample addressed in Anchments B, C and D.
E.3 Equipment Mounting Calculations These calculations contain the qualification of the equipment anchorage. Total population ofcalculations is six (6) for DGX System and nineteen (19) for HVX System. Since the anchor bolt pattern is unique for each equipment type, we are proposing 100% review sample.
Attachment F Page1of3-F.
hPE STRESS CALCULATIONS F.1 Large Bore / Small Bore Stress Calculations - Detailed NUPIPE Analysis The population oflarge and small bore pipe stress and related calculations for the two systems include:
DGX HVX Type System System Total Large Bores Stress 15 5
20 Calculations Small Bore Stress 31 1
32 Calculations Filly-two (52) large and small bore piping stress calculations have been identified for review. All stress calculations in this category are based on detailed computer aided calculations using the NUPIPE code. We propose to conduct the review for-these calculations using a two-level process. The first level review will be for 100% of the calculations and would verify that the design information, as stated in the calculations, is comistent with the system design package, applicable design criteria, and other references provided in the calculations.
The seconel level review will verify that this design information is correctly and accurately entered in the NUPIPE computer code and the computer output supports the conclusions of the calculaticins. We propose to review a sampling (approximately 10% with a minimum sample size of 3) for this second level review due to their repetitive nature. The rationale for selecting a 10% sample is that the first level review would verify that the design information for 100% of the calculation is appropriate. The 10% sample verifies the repetitive task ofincorporation of the design information as input to the NUPIPE computes code.
The repetitive tasks include developing the piping model, preparing the NUPIPE input data, perfonning the computer analysis, and verifying that the computed stresses are within code allowable stresses.
F.2 Small Bore Stress calculations - Simplified Analysis There are no small bore pipe stress calculations for the two systems which are evaluated using simplified analysis methods.
All of the small bore pipe stress calculations identified for the two systems are based on detailed analytical methods using the NUPIPE code, thereibre the review method for this category of calculations will be addressed by the method as described in F.1 above.
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- O Attachment F Page 2 of 3.
g F.3 Tubing Stress Calculations The population of tubing stress and related calculations for the two systems include:
i
'DGX IIVX Type System System Total Tubing Stress Calculations 18
.* 7 '
65 These types of calculations are primarily based on implen,a..tation of Procedure NETM-25 and a limited number of special case supplemental calet.lations which are referenced in each calculation as applicable. The basis for implementing these procedural requirements is-to prepare a' series of Jculations which repetitively address the following eight individual design considerations:
- 1. Tabulate the applicable analytical data from the affected EK series isometric drawing and NETM-25.
- 2. Tr.hulate maximum allowable spans and minimum thermal offset per procedure.
- 3. Identify assumption or approaches which may differ frc n procedure.
- 4. Tabulate all applicable references.
S. Tabulate actual maximum spans and minimum offset from isometnc.
- 6. Calculate required thermal offset based on operating temperature.
calculation et root valve location.
- 8. Verification that support loads meet BZ-600 series support capacities (if applicable).
There are approximately 65 tubing stress calculations which are formatted in this manner.
. Based on the rationale presented in F.1 above, we propose to review a minimum'of 3 or
- 10%, whichever is greater, of these types of calculations for each system (i.e. 3 for DGX and 5 for HVX.)
. F.4 Vent and Drain Stress Calculations i
The population of vent and drain pipe stress and related calculations for the two systems include:-
DGX HVX Type
. System System -
Total Vent and Drain Stress -
48 9
57 Calculations c
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Attachment F -
Page 3 of 3 4
These types 'of calculatic::s are based on implementation of Procedure NETM 24,
- Millstone Nuclear Power Station Unit 3 Design and Installation of Small Bore Piping, and ~
based on approaches. defined in master Calculation (s) NP(F)-C.1 HVR / EGA / EGS /
EGF / EGO.. The methodology for implementing the above requireme.ts is to prepare a series of calculations which repetitively address.the following 15 individual design considerations for each piping configuration:
- 1. Local model configuration based on referenced design ISO.
- 2. Tabulation of piping data, properties, material allowables, etc., from referenced -
sources.
- 3. Tabulation of component, hardware weights from referenced sources.
- 4. Calculation for configuration frequency check to verify applicability of method.
- 5. Calculation for critical stress location.
6.' Calculation for Eq. 8 (pressure and dead weight stress evaluation).
- 7. Tabulation of applicable local pipe, building and design acceleration values.
- 8. Calculation for seismic stress (normal / upset).
- 9. Calculation for Eq. 9 compliance (Steps 6 and 8 above).
- 10. Calculation for seismic stress (energency/ faulted),
- 11. Calculation for Eq. 9 compliance (Steps 6 and 10 above).
- 12. Tabulation of header thermal displacement and branch line thermal expansion.
- 13. Thermal stress enklation.
- 14. Calculation for Eq.10 compliance.
- 15. Flange load check.
There are approximately 57 vent and drain calculations. Based on the rationale presented in A.1, we propose to review a minimum of 3 or 10%, whichever is greater, of these types of calculations for each system (i.e. 5 for DGX and 3 for HVX.)
F.5 Time History Load Csiculations No time history load c.ticulations have been identified as applicable to the design basis for the DGX and IIVX systems.
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