This document: Copyright © 1999 Peter Turula
    Contents:

A - Overview
B - Regulatory Aspects
C - Code Purpose and Background
D - Structure of the Code
E - General Requirements
F - General Requirements - Div. 3 "NuPack"
G - Material
H - Design, Part I (Class 1)
I - Design, Part II (Other)
      Allowable Stresses Comparison Table
J - Non-ductile Fracture
K - Thermal Stresses
L - Buckling Review
M - Bolted Closures
N - Fabrication and Inspection
O - Examination
P - Testing
Q - Overpressure Protection and Stamping


OVERVIEW
WHY APPLY THE ASME CODE
TO PACKAGING ?

Administrative reasons
  • NRC Regulatory Guides 7.11 and 7.6
  • NRC Standard Review Plan (Draft)
  • DOE Packaging Guides
Technical reasons   . . .

Page A 1

WHY APPLY THE ASME CODE
TO PACKAGING ?
(continued)

Technical reasons
  • Preeminent pressure vessel code in the country
  • Accepted in all states and in many other countries
  • Long history of successful use - since 1915
  • Technically sound consensus code
  • Has broad review

NEW:   ASME Code Division for Nuclear Packaging

Page A 2

Presentation   B

REGULATORY ASPECTS


Structural Design of Packaging
for Radioactive Material

Regulatory Aspects

                  by Peter Turula, Ph.D., P.E.


Page B 0

REGULATORY ASPECTS
PRESENTATION

This presentation will cover:

  • Regulatory background
  • Structure of federal regulations
  • Structure of Titles 10 and 49
  • Packaging authority
  • DOE packaging categories
  • NRC Regulatory Guides and other guidance
  • Regulatory / Code interface

Page B 1

REGULATORY BACKGROUND


  • All federal regulations result from legislation

  • Laws focus on an issue
  • Laws identify a responsible federal agency

  • Federal agencies issue implementing regulations
  • Federal regulations have the force of law

Page B 2

REGULATORY BACKGROUND
(continued)

  • Federal agencies also issue orders and procedures

  • They are binding on federal employees

  • Can be binding on the public

NEW:

  • DOE Orders give "Necessary and Sufficient" rules

  • "Implementing Procedures" provide the guidance

Page B 3

STRUCTURE OF FEDERAL REGULATIONS


  • Called:   Code of Federal Regulations   (CFR)
  • CFR is divided into 50 Titles
  • Each Title covers a broad topic;
            e.g., Title 10 covers energy;
            29 - labor;   49 - transportation
  • Titles are divided into Subtitles, Chapters,
            Subchapters and Parts
  • Parts cover specific items

Page B 4

STRUCTURE OF FEDERAL REGULATIONS
(continued)


Subtitles, Volumes, Chapters and Subchapters are
"invisible"

For example:

Title 49, Part 173 of the Code of Federal Regulations is
called 49 CFR 173.

Also, it is in the Second Volume of that Title, as
Subtitle B, Chapter I, Subchapter C, but nobody cares.

Page B 5

STRUCTURE OF FEDERAL REGULATIONS
(continued)


  • Title 10 covers energy   (was AEC)

      -   Department of Energy   (DOE)
      -   Nuclear Regulatory Commission   (NRC)

  • Title 49 Covers Transportation

      -   Department of Transportation   (DOT)

Page B 6;

STRUCTURE OF TITLE 10
"ENERGY"

Chapter I:   NRC       (Parts   0 - 199)

      Part 50   Nuclear Reactors
      Part 54   NPP License Renewal
      Part 60   Nuclear Repositories
      Part 70   Special Nuclear Materials
      Part 71   Packaging and Transportation of
                  Radioactive Material
                  - this is our key regulation
      Part 72   Interim Storage
...   more   ...

Page B 10

STRUCTURE OF TITLE 10
"ENERGY"
(continued)


Chapter II:   DOE       (Parts   200 - 699)
Chapter III:   DOE       (Parts   700 - 999)
      Part 830   Nuclear Safety Management
Chapter X:   DOE       (Parts   1000 - 1099)
Chapter XI:   Enrichment Corporation
Chapter XV:   Alaska Gas Pipeline
Chapter XVII:   Defense Nuclear Facilities Safety Board

Page B 11

STRUCTURE OF TITLE 49
"TRANSPORTATION"


Subtitle A:   "Office of the Secretary of
            Transportation"   (Parts 1 - 99)

Subtitle B:   "Other Regulations Relating to
            Transportation"   (Chapters I - X,
            Parts 100 - 1399)

Page B 12

STRUCTURE OF TITLE 49
(continued)

Within Subtitle B:

  • Chapter I   (Parts 100 - 199) covers Research and
        Special Programs,
                Parts 171 - 199 address radioactive and
                    hazardous material packaging and
                    shipping

  • The other nine Chapters ( II through X ) address
            railroads, highways, mass transit, The Coast
            Guard, etc.

Page B 13

PACKAGING AUTHORITY

Based on   49 CFR 173   and   DOE Orders

  • DOE Order 1540.2 "Hazardous Material Packaging
      for Transport - Administrative Procedures" (old)

  • DOE Orders 460.1A / 460.2 Change 1   "Transporta-
      tion and Packaging Safety / Management" (new)

  • 49 CFR 173.413 defers regulations for "Type B"
            packaging to NRC and 10 CFR 71

Page B 14

PACKAGING AUTHORITY
(continued)

(old)
DOE Order 1540.2 requires that each packaging design:

  • Meet DOT packaging standards; that is, comply
            with 49 CFR 171 through 199
  • Satisfy standards equivalent to NRC packaging
            standards;   that is, comply with 10 CFR 71
  • Follow the NRC Regulatory Guide 7.9 format for
            the Packaging Safety Analysis Report (SARP)

Page B 15

PACKAGING AUTHORITY
(continued)

(new)       DOE Orders 460.1 states "Each package and
shipment of hazardous materials shall be prepared in
compliance with Hazardous Materials Regulations of
the Department of Transportation (DOT) [Title 49 Code
of Federal Regulations (CFR) Parts 106-199]."

and       Order 460.2 states "It is DOE policy
that ... shipments will comply with the 49 CFR 106-180
requirements."

49 CFR 173.413 in turn mandates 10 CFR 71.

Page B 16 + ;

PACKAGING CATEGORIES


Type A Packaging

  • Contains no more than a Type A quantity of
            radioactive material,   and
  • meets fissile material limits.

  • Exempt from 10 CFR 71, but covered by 49 CFR

  • Not addressed in this course

Page B 20

PACKAGING CATEGORIES
(continued)

What is an A quantity?

For any radioactive nuclide, Appendix A of 10 CFR 71
specifies the number of curies that may be transported
in a "Type A" package.

For "special form" this amount of material is an "A1"
For "normal form" this amount of material is an "A2"

The number of curies that correspond to an "A2" of a
given nuclide is referred to as the "A2 value" for that
nuclide.

Page B 21

PACKAGING CATEGORIES
(continued)

Type B Packaging

  • May contain more than a Type A quantity of
            radioactive material

  • May contain fissile material

  • Covered by both 10 CFR 71 and 49 CFR

  • Addressed in this course

Page B 22

PACKAGING CATEGORIES
(continued)

Type B Packaging is divided into three Categories by
the NRC Standard Review Plan (Draft), and by
Regulatory Guide 7.11, based on contents as follow:

I       contents > 3000 A   or   contents > 30,000 Ci

II       30 A <   contents < 3000 A
            and   contents < 30,000 Ci

III       contents < 30 A   and   contents < 30,000 Ci

A is A1 for special form or A2 for normal form

Page B 23

NRC REGULATORY GUIDES


  • Provide guidance

  • Describe acceptable methods

  • Not substitutes for regulations

  • "Not mandatory"

Page B 25

NRC REGULATORY GUIDES
(continued)

Pertinent NRC Packaging Regulatory Guides

  • R.G. 7.4   Leakage Tests on Packages
  • R.G. 7.6   Design Criteria for Structural Analyses
  • R.G. 7.8   Load Combinations
  • R.G. 7.9   Standard Format and Content of SARP's
  • R.G. 7.10   Quality Assurance Programs
  • R.G. 7.11   Fracture Toughness Criteria < 4"
  • R.G. 7.12   Fracture Toughness Criteria > 4"

      7.5 and 7.7 are obsolete administrative guides

Page B 26

OTHER GUIDANCE

  • DOE Guides:   DOE-DP-0049 Rev. 1, "Packing
            Review Guide for Reviewing SARP's"

  • DOE Rad. Materials Packaging Handbook

  • NRC Standard Review Plan (Draft)

  • NRC NUREG's:
        • NUREG/CR-3854   "Fabrication Criteria for
              Shipping Containers"
        • NUREG/CR-6007   "Stress Analysis of Closure
              Bolts for Shipping Casks"

Page B 27

REGULATORY TO CODE
INTERFACE


  • No law, regulation, or Order specifically mandates
            use of the ASME Code

  • Guidance documents recommend the use of the
            ASME Code

  • The ASME Code is "administratively applied"
            to packaging by DOE and NRC

Page B 28

REGULATORY ASPECTS
SUMMARY

DOT:   49 CFR 173   -
DOE:   DOE Orders   -

  • NRC: 10 CFR 71,   for Type B Packagings

NRC Regulatory Guide 7.6   -
NRC Standard Review Plan (Draft)
DOE Packaging Review Guide   -

  • ASME Code,   for Category I Packagings

Page B 29 .

Presentation   F
GENERAL REQUIREMENTS
FOR NUPACK


Section III Division 3   -   NUPACK

Subsection   WA   -   General Requirements

                  by   Peter Turula, Ph.D., P.E.


Page F 0

GENERAL REQUIREMENTS
SECTION III   DIVISION 3   (NUPACK)
SUBSECTION   WA


Scope of NuPack
Parties addressed by NuPack
Required documents - general
Required packaging documents
Code effectivity dates
Loadings
QA and stamping in NuPack

Page F 1

NUPACK SCOPE


NuPack is limited to:

  • [ new - deleted ]
  • design and construction (ASME Terminology)
  • containment systems
  • nuclear spent fuel or high level radioactive waste
  • transport packaging

Page F 2

NUPACK SCOPE
(continued)


Containment system

            =   pressure retaining barrier

            =   containment boundary

Nuclear spent fuel
High level radioactive waste

            are not defined

Page F 3

PARTIES ADDRESSED BY NUPACK

Design Owner (Applicant)
  • includes designer
  • must have an ASME "Certificate of Accreditation"
Packaging Owner
  • must have an ASME "Certificate of Accreditation"
  • must get a written agreement with
            an ASME "Authorized Inspection Agency"
Class TP Certificate Holder (Fabricator)
  • must have an ASME "N-Type Certificate of
            Authorization"

Page F 4

PARTIES ADDRESSED BY NUPACK
(continued)

Responsibilities:

  • Design Owner (usually the Applicant)

            Responsible for the design

  • Packaging Owner (may be the User)

            Responsible for the packaging

Overall responsibility is not assigned to any one party

Page F 5

REQUIRED DOCUMENTS
GENERAL


Design Owner
Packaging Owner
Class TP Certificate Holder

each must have:

  • Quality Assurance Program

  • Applicable ASME Certificate

Page F 6

REQUIRED PACKAGING DOCUMENTS

Design Owner (Applicant):
  • Design Specification
            -   with PE Certification
  • Design Report (SARP ?)
            -   with PE Certification
            -   with independent review
  • Certificate of Compliance
Packaging Owner:
  • Construction Specification
            -   with PE Certification

Page F 7

REQUIRED PACKAGING DOCUMENTS
(continued)


Class TP Certificate Holder (Fabricator):
  • Construction Procedures
  • Shop Drawings
  • Construction Report

  • Data Report
            -   Certified
  • Code Stamp

Page F 8

CODE EFFECTIVITY DATES


The Design Specification must establish
the Code Edition and Addenda (date)
which must not be earlier than
one year prior to the date of filing
of an Application for the Certificate of Compliance.

Materials may be to a different specification date, must
satisfy the requirements of the same specification
for the Design Specification Code effectivity date.

Page F 9

LOADINGS

Operating Conditions
  • Normal Operating Conditions
      -   Normal Conditions of Transport   (NCT)
      -   In Plant Handling Conditions
  • Hypothetical Accident Conditions   (HAC)

Test Conditions   - the greater of:
  • 1.5   x   Maximum Normal Operating Pressure   (NMOP)
  • 1.25   x   Maximum Normal In Plant Handling
                  Pressure   (MNIP)

Page F 10

QA AND STAMPING
IN NUPACK


Much of Subsection WA deals with QA and QC:

  • reports and documentation
  • inspection responsibilities
  • records retention
  • marking and identification

WA includes a requirement for a code stamp

Page F 11

SUMMARY
SECTION III   DIVISION 3   (NUPACK)
SUBSECTION   WA


Calls for several new documents
Defines new ASME authorizations
Adds PE certification and independent reviews
Defines loadings
Deals with QA and stamping

Page F 12 .

Presentation   H
DESIGN REQUIREMENTS
PART   1   OF   2


ASME Code Section III Division 1 NB (Class 1)

Design Rules   -   NB-3000

                  by   Peter Turula, Ph.D., P.E.


Page H 0

DESIGN REQUIREMENTS
NB-3000
( in Sec.III Div.1 Class 1 )


  • General design rules
  • Load criteria (categories) and load combinations
  • Categorization of stresses - stress intensity
  • Categorization of stresses - ASME stresses
  • Stress (intensity) limits
  • Vessel Design
  • Significance of stress limits

Page H 1

DESIGN REQUIREMENTS
APPLICABLE RULES
( why NB ? )

DOE's Packaging Review Guide
DOE's Packaging Handbook (maybe)
NRC's Standard Review Plan (maybe)

      For Category I Containments,
      use ASME Sec. III, Class 1   (NB)

also:
NRC Reg. Guide 7.6:

      Portions of the ASME Class 1 approach are used
      for spent (irradiated) fuel containment vessels

Page H 2

DESIGN REQUIREMENTS
APPLICABLE RULES
(continued)

DOE Packaging Review Guide

and   NRC NUREGs:

  • NUREG/CR-3019 (UCRL-53044)
      -   Recommended Welding Criteria   . . .

  • NUREG/CR-3854 (UCRL-53544)
      -   Fabrication Criteria   . . .

Call out ASME III NB, ND, NF and NG;
and Section VIII Division 1

Page H 3

STRUCTURE OF
SECTION III   CLASS 1
DESIGN RULES


NB-3000:

  • NB-3100 General Design
  • NB-3200 Design by Analysis
  • NB-3300 Vessel Design

  • NB-3400 Pump Design
  • NB-3500 Valve Design
  • NB-3600 Piping Design

Page H 4

GENERAL DESIGN
NB-3100
( details )


Contents:

  • NB-3110 Loading Criteria - defines load categories

  • NB-3120 Special Considerations - corrosion,
            welding, etc.   (materials)

  • NB-3130 General Design Rules - for vessels under
            external pressure.   (buckling)

Page H 5;

LOADING "CRITERIA"
(load categories)
NB-3110


NB-3110 refers back to NCA-2142 for definition of
loading categories.

The ASME Code does NOT define or categorize
the loads (by type or level):
"the Owner or his designee shall identify the loadings"

NRC Reg. Guide 7.6 provides some loading guidance.

Page H 10

LOADING CRITERIA
NB-3110
(continued)

NCA-2142 establishes load categories as follows:

  • Design loads   (defined in the Code)

  • Service loads   (from Owner and Jurisdiction)

      -   Level A   [ normal ]
      -   Level B   [ upset ]
      -   Level C   [ emergency ]
      -   Level D   [ faulted ]

  • Test loads   (defined in the Code)

Page H 11

LOADING CRITERIA
NB-3110
(continued)


Design Load (pressure, temperature and mechanical):

  • Defined by NCA-2142.1 on the basis of the Service
            Loads

  • "Worst case" Level A Service load condition

  • This is the nominal or enveloping load

Page H 12

LOADING CRITERIA
NB-3110
(continued)

Service loads:

NRC Regulatory Guide 7.6 states (Part B, Discussion):
"The design criteria for normal transport conditions
are similar to the criteria for Level A Service Limits."

(Part C, Regulatory Position)   Specifies stress limits
for NCT that are the ASME Design limits
(this IS consistent since the Design Load is
the Level A Service load "envelope"),   and

Level D Service limits (almost) for the HAC loads.

Page H 13

LOADING CRITERIA
NB-3110
(categories summarized)

Normal Conditions of Transport (NCT) loads are treated
as Level A Service Loads, so:

  • Level A Service limits apply.
  • Design limits also apply, because the most severe
            Level A Load also defines the Design Load

Hypothetical Accident Conditions (HAC) loads are
treated as Level D Service Loads.

Hydrostatic Pressure Acceptance test is a Test Load.

Page H 14

LOADING CRITERIA
NB-3110

Load combinations:

  • NCA-2142.2 states that the Design Specification is
            to provide the loading combinations.

  • NB-3111 lists various loading that are to "be taken
            into account" but does not address
            combinations.

  • However Reg. Guide 7.8 does provide a load
            combination table - which follows a "common
            sense" worst case combination scheme.

Page H 15;

DESIGN BY ANALYSIS
NB-3200
( details )


Contents:

  • NB-3210 "Design Criteria" presents the ASME
            stress categories scheme

  • NB-3220 Provides stress limits, except for bolting

  • NB-3230 Provides stress limits for bolting

Page H 20

CLASSIFICATION OF STRESSES
( NB-3210)

NB-3213 discusses stress categories (details later):

  • Stress intensity (definition) and principal stress

  • Structural Discontinuity

  • Conventional stress analysis terms -
            normal, shear, membrane and bending,

  • ASME Code stress analysis terms

      -   Primary vs. Secondary
      -   Local stress   and   Peak stress

Page H 21

CLASSIFICATION OF STRESSES
STRESS INTENSITY

All Section III NB stress limits are expressed as
stress intensity, which is not equivalent to stress.

Defined at any infinitesimal point in the material as
  • Twice the maximum shear stress
            which is identical to
  • (max principal stress) - (min principal stress)
Max and min are the algebraic, not absolute, values.

Stress intensity is a "scaler" not a vector or tensor.

Superposition is NOT valid for stress intensities.

Page H 22 + 2

CLASSIFICATION OF STRESSES
STRESS INTENSITY
(continued)

Stress intensity - examples:

Simple tension:
    stress intensity = tensile stress

Simple compression:
    stress intensity = absolute value of the stress

With tension as the principal stress in one direction
and compression in the other,
the stress intensity is the sum of the absolute values
of the individual stresses.

Page H 23

CLASSIFICATION OF STRESSES
STRESS INTENSITY
(continued)

More stress intensity examples:

For shells of revolution with low internal pressure
one principal stress is near zero, so:

if both (tangential and hoop) stresses are same sign;
the stress intensity is the larger stress at any point

if the stresses are of opposite sign (knuckle region)
the stress intensity is the sum of the absolute values

Page H 24

CLASSIFICATION OF STRESSES
STRESS INTENSITY
(continued)

More on stress intensity:

For most real structures, computation of stress
intensity is complex.

For high internal pressure, the surface pressure stress
is a significant factor.

Computation of stress intensity is usually left to the
computer, except for the simplest of cases.

Page H 25 + 6

CLASSIFICATION OF STRESSES
CONVENTIONAL TERMS

NB-3213 Terminology continued:

  • Stress intensity

  • Conventional stress analysis stress terms

      -   normal
      -   shear
      -   membrane, and
      -   bending

  • ASME Code Terms (as follows):

Page H 26 + 2;

CLASSIFICATION OF STRESSES
ASME CODE TERMS






Primary (P)
Secondary (Q)
required for static equilibrium with the external loads
produced by internal resistance within the component
NOT self limiting
is self limiting
load controlled
deformation controlled
e.g.:
Pressure stress
e.g.:
thermal stress, or geometric discontinuity stress


Page H 31

CLASSIFICATION OF STRESSES
ASME CODE TERMS
(continued)


Membrane and Bending:

Membrane stress (Pm) is the averaged stress across
a cross section.

Bending stress (Pb) is the increment over the
membrane stress due to stress variation across the
cross section.

Page H 32

CLASSIFICATION OF STRESSES
ASME CODE TERMS
(continued)


Local Primary Membrane Stress (PL)

Secondary membrane stresses that require large
deformations before they are relieved,
e.g., at nozzles and brackets.

Code gives spacing rules for nozzles and brackets.
( See NB-3213.10 )

Page H 33

CLASSIFICATION OF STRESSES
ASME CODE TERMS
(continued)


Peak stress (F)

The increment of stress added to P or Q
caused by a local discontinuity, or local thermal stress,
or by a stress concentration.

Page H 34;

STRESS INTENSITY LIMITS
( NB-3220 )


The limits are based on:

Design Stress Intensity Values - Sm

Tabulated in Section II

Typically,   Sm is the lesser of
2/3 yield or 1/3 ultimate

Page H 40

STRESS INTENSITY LIMITS
(continued)


For Design Loadings the limits (NB-3221) are:

1.0   Sm   for   general primary membrane (Pm)
1.5   Sm   for   local primary membrane (PL)
1.5   Sm   for   primary membrane plus bending
                (Pm+Pb) and (PL+Pb)

In addition, the external pressure design provisions
of NB-3133 apply.

Page H 41 + 1

STRESS INTENSITY LIMITS
(continued)


Level A Service loading limits (NB-3222):

  3   Sm   for   general or local primary membrane (PL)
            plus bending (Pb) plus secondary (Q)

      Sa   for the above   plus   peak (F)

where Sa is a stress intensity that takes into account
"strain cycling fatigue data"

Page H 42 + 1

STRESS INTENSITY LIMITS
(continued)

For Level D Service loading limits NB-3225 points to
Appendix F.   F-1331.1   gives:

  • the lesser of   2.4 Sm   or   0.7 Su
            for   general primary membrane (Pm)

  • the lesser of   3.6 Sm   or   1.05 Su
            for general or local primary membrane plus
            bending   (But see Reg. Guide 7.6)

Special limits for pure shear, triaxial load and bearing.

Page H 43

STRESS INTENSITY LIMITS
(continued)


NRC Reg. Guide 7.6 provisions:
( also:   ASME Sec. III Div. 3   WB-3000 )

Same as NB-3000   except

Level D limit is 1.0 Su,   not 1.05 Su

[ see Fig. WB-3224-1 ]

Page H 44

STRESS INTENSITY LIMITS
(continued)

For Test Loadings (hydro, not drop) the limits
(NB-3226) are:

0.9 of tabulated yield strength at temperature (Sy)

            for general primary membrane (Pm)

(1.07   up to   2.15)   Sy   (using interaction equations)

            for   primary membrane plus bending (Pm+Pb)

Page H 45 + t;

VESSEL DESIGN


NB-3100 - General
NB-3200 - Design by Analysis
NB-3300 - Vessel Design:

  • In addition to NB-3100 and NB-3200 requirements:

  • Provides the modified "pr/t" and "pt/2t" formulas

  • Provides extensive vessel detailing requirements

Page H 50

DESIGN REQUIREMENTS
SUMMARY


Stresses approaching yield for normal conditions,
approaching ultimate for hypothetical conditions,
and exceeding ultimate for test conditions,
are allowed.

Why is this safe?

Stresses are linear elastic analysis stresses,
not real inelastic analysis stresses.

Page H 51 + 2

DESIGN REQUIREMENTS
SUMMARY
(continued)


  • Reg.Guide 7.6,   NUREGs
            and   DOE Packaging Review Guide

  • Categorization of loads   and   Reg.Guide 7.8
  • Categorization of stresses
  • Stress intensity   and   stress intensity limits

NuPack,   in WB-3000 (Design):

  • Streamlines the process somewhat
  • Focuses on packaging

Page H 52 .

Presentation   I
DESIGN REQUIREMENTS
PART   2   OF   2


ASME Code Section III Division 3 - "NuPack"

Design Rules   -   WB-3000

and miscellaneous other sections:

ND, NF, NG and Section VIII

                  by   Peter Turula, Ph.D., P.E.


Page I 0

DESIGN REQUIREMENTS
SECOND PART


  • NuPack Design (WB-3000)

  • Subsection ND (Category II Packaging)
  • Section VIII Division 1 (Category III Packaging)
  • Subsection NF (Other safety components)
  • Subsection NG (Fissile Fuel Baskets)

  • An Example

  • Summary

Page I 1

NUPACK DESIGN
(WB-3000)

NuPack - Design

  • Streamlined and focused on packaging   ( ? )

Subsections:

  • WB-3100 General Design
  • WB-3200 Design by Analysis
  • WB-3300 Containment Vessels

All references to pumps, etc.,   have been deleted

Page I 2

NUPACK - GENERAL DESIGN
(WB-3100)


WB-3111 Addresses loadings:

  • Max Normal Operating Pressure   (MNOP)
      -   Uses one year definition

  • Max Normal In-plant Handling Pressure   (MNIP)

Page I 3

NUPACK GENERAL DESIGN
(WB-3100)
(continued)


WB-3112 Covers packaging "Operating Conditions"

Operating Conditions   (same as WA-2121)

  • Normal Operating Conditions

      -   Normal Conditions of Transport   (NCT)
      -   In Plant Handling Conditions

  • Hypothetical Accident Conditions   (HAC)

Page I 4

NUPACK GENERAL DESIGN
(WB-3100)
(continued)

WB-3113 Covers Test Conditions

Test Conditions   (same as WA-2122)
Containment system shall be pressure tested to the
      greater of:

  • 1.5 x Maximum Normal Operating Pressure
            (MNOP)
  • 1.25 x Maximum Normal In Plant Handling
            Pressure (MNIP)

Page I 5

NUPACK GENERAL DESIGN
(WB-3100)
(continued)


WB-3120 Covers Special Considerations

  • Corrosion, cladding and welding

WB-3130 Covers General Design Rules

  • Buckling and Instability - tbd

            reference to Code Case N284 is deleted
            ( covered in Presentation   L )

Page I 6

NUPACK DESIGN BY ANALYSIS
(WB-3200)

WB-3210 "Design Criteria" presents the same ASME
stress categories scheme as in NB-3210.

WB-3220 "Stress Limits"

    WB-3221 stress limits for Normal Operating
          Conditions (including NCT):
          Combines limits for
                  Level A Service Loads from NB-3222,
                  and   Design Loads from NB-3221

Page I 7

NUPACK DESIGN BY ANALYSIS
(WB-3200)
(continued)


WB-3220 "Stress Limits" (Continued)

  • WB-3224 stress limits for HAC:

            Numerically like Level D Limits of NB-3225
                EXCEPT:
            No reference to Appendix F; therefore,
            No provision for:
                • (F-1340) "Plastic System Analysis"
                • (F-1341.2) "Plastic Analysis"

Page I 8

NUPACK DESIGN BY ANALYSIS
(WB-3200)
(continued)

Special provisions of WB-3200:

WB-3217: for connected concentric shells
  differential thermal expansion stresses
  must be treated as primary, not secondary.
            ( covered in Presentation   K )

WB-3221.9 addresses analysis for cyclic operation.

WB-3224 limits maximum HAC stresses to 1.0 Su,
            not the NB-3225: Apx F limit of 1.05 Su.

Page I 9;

OTHER COMPONENTS GROUPS
AND CATEGORIES

Containment
  • Cat. I   -   NB - Class 1 Nuclear Vessels
  • Cat. II   -   ND - Class 3 Nuclear Vessels
  • Cat. III   -   Sec VIII. Div. 1 - General Vessels

Criticality
  • All Cat.   -   NG - Reactor Core Supports

Shielding and Other Safety
  • Sec. VIII Div. 1 or NF - General Vessels   (shells ? )
  • Sec. III NF - Component Supports   (supports)

Page I d1

SUBSECTION ND

Subsection ND applies to
            Category II Packaging Containments

ND-3000 - Design   (Rules for "Class 3" nuclear vessels)

  • ND-3300 Vessel Design

        • ND-3321 Stress limits:

              Based on normal stress limits,
              not on stress intensity limits.

Page I d2

SUBSECTION ND
(continued)


Material allowable stress values, S, are taken from
Section II, Part D, Table 1A (Fe), Table 1B (non Fe),
and   Table 3   for bolts.

Allowable stress values, S, for ND are generally
different from stress intensity values, Sm, for NB.

Page I d3

SUBSECTION ND
(continued)

ND-3321 Stress limits are

1.0 S   for Level A (NCT) membrane stress

1.5 S   for NCT membrane plus bending stress

2.0 S   for Level D (HAC) membrane stress

2.4 S   for HAC membrane plus bending stress

Applied to conventional stress, not to stress intensity.

Page I d4

SUBSECTION ND
(continued)


also

  • Subsection ND allows design by rule and provides
            extensive guidance for shell thickness
            determination.

Page I d5;

SUBSECTION NF
(NPP COMPONENT SUPPORTS)
NF-3000 - Design

Applied to a packaging's "other safety components"
other than containment or criticality control

  • NF-3100   General Design Requirements
  • NF-3200   Plate and Shell Type Supports -
                        (Vessel Skirts and Saddles)
  • NF-3300   Linear Supports -             (Struts, Beams, Lugs)
  • NF-3400   Standard Supports -             (Catalog Items)
  • NF-3500   Component Supports
  • NF-3600   Piping Supports

Page I f1

SUBSECTION NF
NF-3000 - Design
(continued)


  • NF-3200, NF-3300, and NF-3500 have the most
            applicability to packaging

Note:       NF-1130 and NF-1210 give definitions of
            categories of supports

  • Table NF-3131(a)-1   ("road map")   provides
            a matrix of paragraphs and procedures
            applicable for specific types of support
            design

Page I f2

SUBSECTION NF
NF-3000 - Design
(continued)


NF-1215 defines primary and secondary members

  • Primary members carry load
            "load path" members

  • Secondary members
            mostly there to maintain geometry
            stress less than 50% of "allowable"

NOT like primary vs. secondary loadings in NB !

Page I f3

SUBSECTION NF
NF-3000 - Design
(continued)


  • Applies Class 1 design load stress limits (NB)
            for Class 1 supports.

  • But for service loads, uses a stress limit factor
            approach applied to design limits.

  • Class 3 (for packaging category II) defers to
            Class 2 for stress limits - essentially NC
            which is like ND rather than like NB.

Page I f4

SUBSECTION NF
NF-3000 - Design
(continued)

  • For Class I bolting:   applies a stress limit scheme
            devised especially for NF bolts.

      • For simple tension bolts the allowable
            is 50 % of ultimate strength.

      • Otherwise lower percentages apply.

      • For pure shear, the allowable
            is only about 10 % of ultimate strength.

  • For Class 3 bolting:   applies Class 1 stress limits.

Page I f5;

SUBSECTION NG
NG-3000 - Design


Sec. III - NG:   Design by analysis approach for
      core support structures
            -   applied to shipping cask fuel baskets.

Stress intensity values are taken from Tables 2A, 2B,
      and 4, Section II, Part D, Subpart 1
            -   same as NB.

NG is concerned with "pressure surges" due to reactor
hydrodynamics - which do not apply to casks.

Page I g1

SUBSECTION NG
NG-3000 - Design
(continued)


NG-3221 specifies design load limits -
            on   Pm   and   Pm+Pb   but not on   PL.

NG-3222 specifies same limits as NB-3222 for
            Level A Service Loads,   but:
      adds plastic analysis and limit analysis rules,
            and design by test rules.

NG-3225 specifies same limits as NB-3225 for
            Level D Service Loads

Page I g2

SUBSECTION NG
NG-3000 - Design
(continued)


NG-3227 specifies "special stress limits"
for Level A Service Loads, similar to NB limits, for:

  • bearing loads       •   pure shear

  • triaxial load       •   mechanical connections

Twice the special limits apply to Level D Service Loads.

Page I g3;

SECTION VIII
DIVISION 1


Applicable to:

  • Category III Containments,   and

  • Non-containment Safety Related Components

Page I v1

Comparison of Containment Vessel Allowable Stress Intensities

Material316 SS Plate, SA240-316, (S31600)
Tensile or Ultimate StrengthSu = 75 ksi
Yield StrengthSy = 30 ksi
Allowable Stress IntensitySm = 20 ksi ( Section II, Table 2A )
Allowable Stress S = 18.8 ksi ( Section II, Table 1A )
Calculated Stress IntensityPm = Membrane, Pb = Bending, also Sigmam, Sigmab

Sec.III Div.1 (Cl 1) & Div.3
Subsec. NB & WB; NF & NG
(NB, WB, NF & NG-3220) 		Sec.III - Div.1
ND (Class 3)
(ND-3320) 		Sec. VIII
Div. 1
(UG-23)
Normal Conditions of Transport (numerical values in ksi)
Pm <  Sm = 20
Sigmam <  S = 18.8
Sigmam <  S = 18.8
Pm+Pb <  1.5 Sm = 30
Sigmab+Sigmam <  1.5 S = 28.2
Pm+Pb+Q <  3 SmC = 60
Not Limited
Hypothetical Accident Conditions (numerical values in ksi)
Pm <  2.4 SmA = 48
Sigmam <  2.0 S = 37.6
No Guidance
Pm+Pb <  3.6 SmB = 72
Sigmab+Sigmam <  2.4 S = 45.1
A Pm must be the lesser of 2.4 Sm or 0.7 Su
B Pm+Pb must be the lesser of 3.6 Sm or 1.05 Su (1.0 Su in WB)
C Pm+Pb+Q must also be less than Sa which considers fatigue.

Page I v2;


DESIGN REQUIREMENTS
SUMMARY


  • Design to NB-3000 was covered in part 1

  • NuPack Design (WB-3000)

  • Subsection ND, NF, NG, and Section VIII Div. 1

  • Summary

Page I v5;


Presentation   K   -   THERMAL



Thermal Stresses and Deformations

                  by   Peter Turula, Ph.D., P.E.


Page K 0

THERMAL


  • Thermal stresses

  • Special ASME rules

  • Cask examples

  • Summary

Page K 1

THERMAL LOADINGS
AND STRESSES


A uniform (linear) temperature field for a homogeneous
material results in no thermal stress.

Thermal stresses caused by:

  • Materials with different coefficients
            of thermal expansion,   and/or

  • Nonlinear thermal gradients.

Page K 2

THERMAL STRESS
CLASSIFICATION


ASME generally classifies thermal stresses
as "secondary" - does not mean un-important.

Reason - thermal stresses are self-limiting;
            i.e., deformation controlled.

Given enough strain, the stress will go away;   whereas,
for gravity load, stress does not go away with strain.
( For pressure load, the stress reduction with strain
is a second order effect. )   -   but   . . .

Page K 3

THERMAL STRESS
CLASSIFICATION
(continued)

A high level of strain needed to reduce
thermal load stresses may not be acceptable.

In general, ASME is not concerned with operability.

But, ASME Code Section III Division 1   recognizes
the potential problem with large thermal load strains
by using primary stress limits for elastic follow-up
thermal stresses, where a large elastic displacement
in a large component can cause inelastic response
in a smaller component connected to the large one.

Page K 4

THERMAL STRESS
CLASSIFICATION
(continued)

Thermal loading of concentric cylinders:

Sec. III Div. 3 Fig. WB-3217-1 Note (7) and Note (8)
recognizes an elastic follow-up type problem
for concentric cylinders,
where a thick cylinder under elastic strain
may over-load a constrained cylinder, and the joint.

Primary load limits apply in this case.

In particular, the buckling evaluation rules
for primary stresses apply.

Page K 5

THERMAL STRESS
EXAMPLE I

Consider two rigidly connected concentric cylinders,
a thick outer cylinder and a thin inner cylinder,
200 F thermal gradient (heat generating contents).

Stress on the inner cylinder could approach:

E Alpha DeltaT
  =   (30,000 ksi) (6.5ù10-6) (200)   =   39 ksi

This is less than   3 Sm   but not less than   Sm.

Also:   buckling must also be considered.

Page K 6 + 5

THERMAL STRESS
EXAMPLE I
(continued)

Elastic finite element analysis shows:

( for buckling analysis )

  thermal membrane stress in the inner cylinder:   about   28 ksi

  membrane plus bending is:   about   40 ksi

( for stress analysis )

  membrane stress intensity is:   about   30 ksi
  discontinuity stress intensity is:   about   75 ksi

Page K 7;

THERMAL CONCERNS
IN CASKS


The stress itself due to thermal loading is usually
not a problem.   The problems are:

  • Relative movement of the closure flanges

  • Gross distortion of non-containment structures

  • Failure or weakening of material due to high
              temperature

Page K 10

THERMAL STRESS
EXAMPLE II

Heavy homogeneous cask made of one material
under thermal gradient loadings (internal heat source):

Normal condition of transport:

  • Bolted up isothermal - no thermal stress
            Steady state:   cold outside and hot inside.
                                    dT = 300 F

Hypothetical accident condition:

  • Fire temperature outside:       dT = 600 F

Page K 11 + 1

THERMAL STRESS
EXAMPLE II
(continued)

The ASME Code requires that the stresses in the
material be limited to allowable values.

But, the Code does not address operability,
i.e., "containment" requirements.

For a cask with o-ring seals (esp. metallic),
in lieu of extensive testing,
the containment criterion used is
no relative movement at the closure surfaces.

Page K 12

THERMAL STRESS
EXAMPLE II
(continued)


Thermal stresses in the cask material
were found to be manageable -
about   1 Sm   locally, and less generally.   ( <<   3 Sm )

However, calculated thermally induced unrestrained
displacements were 12 mils shear and 5 mils axial.

Page K 13 + 4

THERMAL STRESS
EXAMPLE II
(continued)


To restrain this movement, a total bolting force of
at least   13ù106 lb   would be needed

  -   more than twice any reasonable bolting capacity

Hypothetical accident load bolt loads are about
10 times any reasonable bolting capacity.

Page K 14 + 6

THERMAL
SUMMARY


  • Special ASME rules

  • What is important to packaging

  • Some cask examples

Page K 15 .


Presentation   L   -   BUCKLING



Structural Buckling Considerations

                  by   Peter Turula, Ph.D., P.E.


Page L 0

BUCKLING


  • Buckling in packaging
  • NRC Regulatory Guide 7.6
  • ASME Rules, NB and other Subsections
  • Example
  • ASME NuPack (WB)
  • Code Case N-284 and Subsection NE

Page L 1

BUCKLING
BASIC CONCEPTS

Buckling is an unstable deformation of a structure
subjected to a load - structural instability.

In theory -   buckling is when:
more then one deformed shape function
satisfies the equations defining of structure;
i.e., the solution is not unique.

In practice -   buckling is when:
a small increase in load results in
a large increase of deflection, (at small strain levels).

Page L 2

BUCKLING
BASIC CONCEPTS
(continued)


Buckling is usually inelastic (pop can),
but it can be elastic (yard stick).

It is a nonlinear phenomenon, but the buckling load
(or stress) can be computed from the linear equations
describing the structural deflections.
(   non-trivial solution to   A x = k B x   )

The "linear" solution is the "eigen value" solution,
and for a simple column it is the "Euler load."

Page L 3

BUCKLING
BASIC CONCEPTS
(continued)

An elastic buckling load for a shell can be found,
but is usually meaningless because plastic deformation
takes place before the elastic buckling load is reached.
Also, imperfections have a very significant effect.

In some elastic structures there is a "snap through"
buckling load that is much lower than the theoretical
elastic buckling load (linear eigen value solution).

So:   an elastic buckling solution is not adequate.

Page L 4

LOADINGS CAUSING
BUCKLING


In packaging, buckling can be caused by:

  • Drop load (dynamic or static buckling)

  • External pressure due to immersion

  • Internal pressure - for unusual geometries

  • Thermal stresses - for concentric cylinders

Page L 5;

BUCKLING
NRC Regulatory Guide 7.6

Paragraph C.5 of Reg. Guide 7.6 proscribes buckling
of a containment vessel, under both NCT and HAC.

It allows elastic-plastic buckling analysis,
which is the basis of the ASME Code procedure
for calculating buckling loads.

Eccentricities of load and geometry must be
considered, and are also covered by the ASME Code.

Page L 10 +

BUCKLING RULES
IN THE ASME CODE

The buckling rules of the appropriate Subsection apply.

For Category I containment vessels:

ASME Section III Division 1 Class 1 NB-3133
has the design rules for buckling,
but only for design (NCT) conditions.

BUT:       NOT in WB-3133   which now has   TBD.

Page L 11 a

BUCKLING RULES
IN THE ASME CODE
(continued)


ASME Section III Class 1:

Requirements for shells under pressure are treated in:

  • NB-3133.3 for cylindrical shells, and

  • NB-3133.4 for spherical shells.

NB-3133.6 provides a procedure for computing
a buckling stress for cylinders under
axial compression, which, if smaller, replaces Sm.

Page L 11 b;

BUCKLING RULES
IN THE ASME CODE
(continued)

For Category I containment vessels under HAC:

  • ASME Section III Class 1 for Level D in NB-3225
              [ but NOT WB ]   points to Appendix F, where:

F-1331.5 limits compressive load stresses to (either):

  • 2/3 ù buckling load or stress determined by
            analyses, or tests of physical models

  • 1.50 ù limit from NB-3133

  • 1.34 ù "MC Code Case"   [ N-284 ]   limit

Page L 12

ASME BUCKLING RULES
OTHER CATEGORIES


For Category II containment vessels:

ASME Section III Class 3 (ND) applies.   For NCT:
ND-3133 is similar to NB-3133 for vessels,
but addresses pressure only, not "axial compression".

Load level D (HAC) is not addressed.

Page L 13

ASME BUCKLING RULES
OTHER CATEGORIES
(continued)


For fuel baskets and criticality control components:

ASME Section III NG (Core supports) applies.
For NCT:   NG-3133 is similar to NB, except that it
addresses pressure differences from hydro-dynamics,
rather than pressures.

For HAC:   NG-3225 for Level D points to Appendix F.

Page L 14

BUCKLING RULES
IN THE ASME CODE

The ASME Rules for buckling are very conservative:

  • were developed for static buckling,
            rather than for dynamic package drop loads.

  • do not consider support conditions (backing)
            found in typical packaging configurations.

Much of the ASME complexity relates to stiffening rings
which are generally not used in packaging.

Page L 15;

BUCKLING
EXAMPLE
(continued)

For the HAC:

NB Load Level D (NB-3225) applies,
      and refers to Appendix F.

Using   F-1551.59(b): "1.5 the limit in NB-3133"
            -   use ratio   -

Required effective impact absorber thickness:

(1.5 in) (30 ft / 4 ft) / (1.5)   = 7.5 in.

Page L 21

BUCKLING RULES
IN NUPACK

WB-3133 no longer calls for Code Case N-284
  - just states:   rules "are under development."

CC N-284 addresses Class MC Components which are
metal containments - covered in ASME Sec. III Part NE.
Allowable stresses in NE are generally 10 % higher
than in NB and WB.

WB-3133 is not limited to design loadings as are
NB-3133 and NE-3133.

Could use CC-284 as a guide, but not NE (MC).

Page L 22

BUCKLING
SUMMARY


  • Buckling considerations in packaging
  • NRC Regulatory Guide 7.6 considerations
  • ASME Rules, NB-3133 and Appendix F
  • Other ASME Subsections
  • Example
  • ASME NuPack (WB), Code Case N-284 and NE

Page L 23 .
This document: Copyright © 1999 Peter Turula
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