ML17318A159
| ML17318A159 | |
| Person / Time | |
|---|---|
| Site: | Harris, Grand Gulf, Vogtle  |
| Issue date: | 11/08/2017 |
| From: | Charkas H, Shanley L, Tegeler B, Vaughan S Jensen Hughes, Nuclear Energy Institute |
| To: | Office of Nuclear Reactor Regulation |
| Brown E DORL/LPL-LSPB 415-2315 | |
| References | |
| L-2017-LLA-0350, L-2017-LLA-0355, L-2017-LLA-0371 | |
| Download: ML17318A159 (34) | |
Text
TMRE Public Meeting Steve Vaughn - NEI Hasan Charkas - EPRI Bret Tegeler - JENSEN-HUGHES Leo Shanley - JENSEN-HUGHES November 8th, 2017
- Teleconference 1
Agenda
- Opening Remarks
- Industry responses to a subset of NRC technical questions (ML17235B148) regarding NEI 17-02, Revision 0
- Robust Targets/Missiles
- Target Characteristics
- Missile Inventory
- Path forward 2
Appendix C Questions
- Responses to Question 11 (a thru i) except 11.h (spalling secondary effect) 3
11.a
- Figure C-1 and Table C-1 do not appear to conclude that the assumptions are representative of plant targets. Specifically, the assumption for exhausts and stacks is described as having the exhaust/stack being supported on both ends.
Generally, and specific to the example in Figure C-1, these targets are unsupported at the end. The guidance should ensure justification is provided to demonstrate the appropriateness of this assumption.
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Response to 11.a
- Appendix C has been revised to include two cases:
Fluid filled pipe case that is supported on both ends of pipe Vent pipe case that is supported by a cantilevered support Table C-6 results reflect these cases 5
11.b
- In Section C.3.1, it is the NRC staffs understanding that M should be the mass of the missile, vice the weight provided in the missile descriptions (mass = weight/32.2). For non-cylindrical missiles, the guidance should ensure that the equivalent diameter used is the diameter of a circle equal to the frontal area of the non-cylindrical missile.
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Response to 11.b
- We are in agreement with the staffs understanding. While missile weight is referenced in the missile descriptions, the appropriate value of mass is used when required, such when the BRL equation for steel is used :
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11.c
- The assumption that only steel missiles are capable of perforating steel targets, should be verified and a justification provided. Also, in the associated reference document that describes the equation above, it is said that the thickness of the steel barrier required to prevent perforation should exceed the thickness for threshold of perforations by 25 percent. It should be considered whether this assumption is significant enough to be added.
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Deformation Failure Mode (Local) Penetration Failure
- Appendix C approach Modes (Local) addresses both local and global effects on steel targets
- Local effects relate to penetration and deformation failures Penetration failure is assessed using BRL equation (empirical ) Deformation Failure Mode (Global)
Deformation failure is assessed using a mechanics-based approach
- Global effects are related to larger deformations 9
Steel missiles considered for penetration
- Penetration into a steel plate requires the missile to have a high areal density and strength to remain intact (e.g., steel-jacketed lead)
- DOE Standard 3014-96 recommends only using BRL equation for rigid missiles
- Thus, for assessing penetration failure, only steel missiles are considered All missiles
- However, all missiles are considered considered credible for for deformation failure modes deformation 10
11.d
- In Section C.3.1, the guidance should provide a table of values of perforation thicknesses for the different targets in question, or an example of this equation used to evaluate one of the targets.
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Response to 11.d
- The following table summarizes three example cases indicating the parameters used in the concrete perforation using the BRL equation:
- 8 Rebar Utility Pole 4x12 timber Parameter Notes Missile Weight (lb) Ref Report Table 5-2 8 1500 200 1" dia 13.5" dia 4"x12" Missile Impact Face Dimensions Ref Report Table 5-2 Assumed Missile Projected Area (in2) Ref Report Table 5-2 0.8 143.1 48.0 Equivalent Diameter, D (in) [Based on Projected Missile Area] 1.0 13.5 7.8 Assumed Concrete Design Strength, f'c (psi) Representative 3,500 3,500 3,500 Median Concrete Strength Factor , Fm NEI 07-13; Section 2.3.1 1.15 1.15 1.15 Concrete Age Factor, Fage NEI 07-13; Section 2.3.1 1.20 1.20 1.20 Dynamci Increase Factor, DIF NEI 07-13; Section 2.3.1 1.25 1.25 1.25 Median Concrete Strength Factor'c (psi) f'c x Fm x Fage x DIF 6,038 6,038 6,038 Vertical Impact Velocity; V vert (fps) V vert = (2/3 V hor) Ref Report Figure C-3 225 179 219 BRL Equation; Report Limiting Perforation Thickness; T (in) Section C3.1 6.1 7.7 3.6 12
- Summary Table C-5 reflecting results for each missile and target combination 13
11.e
- On the Variation of Impact Velocity with Missile Weight (Figure C-3) plot provided shows how missile velocity assumed in this analysis varies with weight. The equation of the line provided represents the best fit line for the data (blue dotted line), but the model uses the green line, which is conservatively shifted up to a maximum velocity of 230 mph. The guidance should include the equation of the line for the green line in order to calculate any missile velocity given missile weight or vice versa.
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Response to 11.e Report will be updated to better describe green line relationship as used in the model:
Vi(W)= -0.0317W + 230.0
- Where, Vi = Missile impact velocity (mph)
W= Missile Weight (lb) 15
11.f
- In section C.3.1, the assumption is that only like materials can cause perforation (steel to steel). The guidance should ensure that a justification is provided to support this assumption.
Response to 11.f
- Refer to Response to 11.c 16
11.g
- Figure C-14, should be reviewed to determine whether it can be used to estimate tank rupture Response to 11.g
- This is a typographical error. Figure number should read Figure C-13 17
11.i
- The data in Table C-5, specifically the minimum perforation thickness in the first column, should be validated and more comprehensive guidance provided regarding the use of the Concrete Perforation equation. Additionally, the evaluations on the failure of the concrete using those values should be addressed should the validation demonstrate that the values should be changed. Similar validation efforts should be performed on vehicle impact and the tree impact evaluation.
Response to 11.i
- This issue is similar to that raised in Question 11.d 18
Responses to Appendix B and Robust Missile & Target Questions 19
5.d., 10.c., and 10.d.
- 5.d. Table 7-2 and Table B - 18 provide the percentage of general target descriptions to be used to adjust fragility (by number of missiles). The calculations for these values should be validated and the methodology to obtain the methodology discussed if unchanged.
- 10.c. It appears that in some cases (example, missiles 10 and 11) an explanation was not provided regarding why these missiles vary widely in damage profiles. As a detailed justification for the results in Table B-14 have not been provided, the guidance should ensure the submittals should provide justification for the assumptions used and conclusions made in this table.
- 10.d. The values in Table B-18 should be validated. Additional guidance should be provided to explain how the data in Tables B-14 through B-17 where used to create the fragility percentages in Table B-18 (and also in Table 7-2*).
- Table 7-2 in Rev. 0 is now Table 5-2 in Rev. 1 20
Response to 5.d., 10.c., and 10.d.
- Comments refer to the development of Tables B-14 and B-18
- Table B-14: Robust Target Missile Matrix
- Matrix showing which missile types can damage which robust target category
- 23 missile types (1 - 23) vs. 9 target categories (A - I)
- Table B-18: Missile Damage Capability
- Provides percentage of total missiles that can damage each robust category (A - I)
- Results repeated in Table 5-2
- Table C.6 (Target Damage Approximations) was updated and will be incorporated in NEI 17-02, Rev. 2
- Tables B-14, B-18, and others in Appendix B, were updated in NEI 17-02, Rev. 1 21
Table C.6 22
Tables B-14 and B-18 23
Use of Table C.6 Results to Create Table B-14 Table B-13: Table B-12:
Robust Target Individual Target Categories and Descriptions and Descriptions Assigned Categories Table C.6:
Individual Target Table B-14:
Damage Robust Target Missile Approximations Matrix Table 3-2*:
Missile Types and Descriptions To next page
- Table 3-2 in Rev. 1 was Table 5-2 in Rev. 0 24
Use of Table B-14 and B-17 to Create Table B-18/Table 5-2 Table B-14:
Robust Target Table B-15: Missile Matrix Unrestrained Missile (from previous page)
Inventories Table B-18:
Missile Damage Table 3-2: Table B-17: Capability Missile Types Average and and Table B-16: Missile Type Table 5-2*:
Descriptions Restrained Inventory Robust Missile Missile Inventories for EEFP Inventories Calculations
- Table 5-2 in Rev. 1 was Table 7-2 in Rev. 0 25
Robust Missile Percentage Example
- Category B: Steel Pipe
- At least 16 diameter and thickness less than 3/8 but at least 0.125
- Crushing/Crimping of > 50%
- Table C.6 worst case results - damaged by all missiles except: 1, 11, 13, 15, 20 Robust Target Category Steel Frame/Grating Concrete Paver Concrete Block Plywood Sheet Channel Section Small equipment Large Equipment Large Steel Frame Gas Cylinder Tank/Drum Utility Pole Cable Reel Storage Bin Wood Beam Wood Plank Metal siding Wide Flange Rebar 3" pipe 6" pipe 12" pipe Vehicle Tree Target Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 B Diesel Generator Air intake (small)
B Diesel Generator Air intake (large) 26
Example - Category B (cont.)
- Damaged by all missiles except:
1, 11, 13, 15, 20
- Results shown in Table B-14 27
Example - Category B (cont.)
Missile Type Percentage 1 - Rebar
- From Table B-17, sum of missile 2 - Gas Cylinder 0.5%
percentages (excluding 1, 11, 3 - Drum, tank 4 - Utility Pole 0.2%
0.1%
13, 15, 20) is 53% 5 - Cable Reel 0.4%
6 - 3 Pipe 11%
- Majority of missiles contributing to 7 - 6 Pipe 0.6%
total are: 3 pipes, metal siding, 8 - 12 Pipe 0.1%
channel sections and trees (42%) 9 - Storage bin 1.6%
10 - Concrete Paver 2.7%
- Other damaging missiles have 11 - Concrete Block relatively small inventories at sites 12 - Wood Beam 1.5%
13 - Wood Plank 14 - Metal Siding 17%
- Table B-18 for Category B: 15 - Plywood Sheet 16 - Wide Flange 0.3%
- Calculated percentage = 53% 17 - Channel Section 7.2%
18 - Small Equipment 1.0%
- Final percentage rounded up to 19 - Large Equipment 0.5%
55% 20 - Frame/Grating 21 - Large Steel Frame 0.5%
22 - Vehicle 0.8%
- Table 5-2 for Category B: 55% 23 - Tree TOTAL 6.8%
53%
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Tables B-18 and 5-2
- Most categories get a modest reduction in damaging missiles (factor of 2 to 3)
- B, C, D, E, F, G
- Most robust targets are thick steel pipes (for crimping/crushing) and concrete roofs 29
4.f.
- In Table 5-2*, 23 missiles are identified, but in Tables and calculations following (including the Appendices) 22 missiles are identified. Missiles in the Section 5* tables are only referred to by number, so the guidance should ensure adequate missile identification and justification is provided to support each missile that has been excluded.
- Table 5-2 and Section 5 are now Table 3-2 and Section 3 Response to 4.f
- 23 missiles used in all tables except Tables 3-3 through 3-8
- Tables 3-3 through 3-8 are missiles created from the deconstruction of buildings
- Only the first 22 missiles are listed, since missile #23 is a tree 30
5.g.
- Examples in Section 7.5 appear to use values different than the percentages in Table 7-2.
The guidance should ensure that examples use verified values.
Response to 5.g.
- Corrected
[Note: Section 7.5 and Table 7-2 are now Section 5.5 and Table 5-2]
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7.b
- Section 9.4 states that if part of the SSC is shielded or inconsequential, a smaller area could be used. The guidance should address the considerations for addressing shielding in calculating area.
Response to 7.b.
- Section 5.3.2 discusses shielding examples and how shielding would be used to change target areas
- Targets may be adjacent to Class 1 buildings or other structures that would preclude missiles hitting targets from those directions
- Penetrations or openings may be partially blocked by piping or supports, reducing the effective opening size
- Section 5.3.2 additionally states:
The basis for crediting shielding in reducing target surface area or providing equivalence to other robust targets/barriers should be justified and documented on a target-specific basis.
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Path Forward
- Deterministic
- #4.c, #4.e - #4.d
- #6.a, #6.b, #6.c - #5.c
- #7.a, #7.c, #7.d
- Clarifications Needed
- #9.a, #9.b - #5.a, #5.b, #5.f, #5.h
- #11.h - #4.a
- Missile Impact Parameter - #2.a
- #2.b
- #9.c Proposed dates for future
- #10a, #10.b teleconferences?
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Questions?
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