ML20215C264
| ML20215C264 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 12/04/1986 |
| From: | Papanic G YANKEE ATOMIC ELECTRIC CO. |
| To: | Mckenna E Office of Nuclear Reactor Regulation |
| References | |
| TASK-03-07.B, TASK-3-7.B, TASK-RR FYR-86-116, NUDOCS 8612150081 | |
| Download: ML20215C264 (22) | |
Text
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- Telephone (617) 872-8100 TWX 7103807619 YANKEE ATOMIC ELECTRIC COMPANY e ~,
SLb 1671 Worcester Road. Framingham, Massachusetts 01701DCC 86-198
.YANKEIE
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December 4, 1986 FYR 86 116 United States Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Ms. Eileen McKenna, Project Manager PWR Project Directorate No.1 Division of PWR Licensing - A
References:
(a) License No. DPR-3 (Docket No. 50-29)
(b) Letter, USNRC to YAEC (FYR 82-207), dated September 1, 1982 (c) Letter, USNRC to YAEC (NYR 85-107), dated July 3, 1985 (d) Letter, YAEC to USNRC (FYR 86-085), dated September 8, 1986 (e) Letter, USNRC to YAEC, dated August 20, 1982 (f) NRC Meeting Summary, SEP Topic III-6 (NYR 86-120), dated June 6, 1986
Subject:
SEP Topic III-7.B. Design Codes, Design Criteria, Loads, and Load Combinations
Dear Ms. McKenna:
The NRC letter of July 3, 1985 requested Yankee to perform three actions in order to resolve the remaining open issues under SEP Topic III-7.B. These actions were recommended by Franklin Research Center (FRC) in their Technical Evaluation Report (TER) C5257-316.
We have taken the actions requested. These consisted of review and re-examination of specific plant design criteria. The results of those reviews are presented in this letter and in the two enclosures. The requested actions and our conclusions are briefly summarized below.
Action No. 1 Review all structures associated with the Safe Shutdown System (SSS) to see if any of the structural elements listed in Section 13 of the TER occur in their designs. For structures which do incorporate these features, assess tio actual impact of the associated code changes on margins of safety.
8612150081 DR 861204 1 ADOCK 05000029 0pf PDR t i (
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United States Nuclear Regulatory Commission December 4, 1986 Attention: Ms. Eileen McKenna Page 2 FYR 86-116 Summary of Results - Action No. 1 Enclosure 1 presents the details of our results for Action No. 1.
Section 13 of the TER identifies structural elements potentially affected by changes in the following design codes:
o American Institute of Steel Construction (AISC), Steel Construction Manual, o American Concrete Institute (ACI), Building Code.
i o American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code.
The term " element" is used to identify either a specific structural component or criteria modification within the applicable code.
Original structural steel components for Yankee Nuclear Power Station (YNPS) were designed in accordance with the requirements of the 5th Edition of the Steel Construction Manual, which is currently in its 8th Edition. Each SSS structure was investigated to determine if it contained any of the ten elements identified in the TER which may be affected by changes in the Steel Construction Manual. The results are as follows:
o Four elements do not exist in SSS structures at YNPS.
o The remaining six elements have been evaluated. All SSS structures, except the MS/FW support structure, meet the 8th Edition criteria.
AISC Code changes for two elements, tension members, and members subject to axial and bending stresses, may affect the MS/FW support structure. These two elements will be evaluated in accordance with the 8th Edition of the manual for nonseismic load combinations. For seismic load combinations, these two elements will be evaluated in accordance with the Seismic Re-evaluation and Retrofit Criteria, DC-1, Revision 3. These evaluations will be performed as part of the seismic analysis of this structure under SEP Topic III-6.
Concrete structures for YNPS were designed originally in accordance with
! the requirements of ACI 318-56. The present manual for nuclear power plant design is ACI 349. FRC based their evaluation on ACI 349-76. Section 13 of the TER identifies nine elements which may be affected by changes in the ACI Codes. The results are as follows:
o Three elements do not exist in SSS structures at YNPS.
o The remaining six elements have been evaluated. All SSS structures, except the MS/FW support structure, meet the ACI 349-76 or ACI 318-77 criteria. ACI Code changes for one element, steel embedments, may affect the MS/FW support structure. This clement will be evaluated in accordance with ACI 349-76 for nonseismic load r
combinations. For seismic load combinations, this element will be l evaluated in accordance with the Seismic Re-evaluation and Retrofit
United States Nuclear Regulatory Commission . Decenber 4,1986 Attention: fMs. Eileen McKenna Page 3 FYR 86-116 Criteria, DC-1, Revision 3. These evaluations will be performed as part of the seismic analysis of this structure under SEP Topic III-6.
The final set of design code changes within the scope of this review pertain to the ASME Boiler and Pressure Vessel Code.
The Vapor Container (VC) was designed originally in accordance with ASME Section VIII, 1956. The code used by FRC for comparison in Section 13 of their TER is ASME Section III, subsection NE, 1980.
Section 13 of the TER identifies ten structural elements which may be affected by changes in.the ASME Code. These have been evaluated and the results are as follows:
o Nine elements do meet the requirements of ASME Section III, 1980, o One element, bellows and bellows expansion joints, was not evaluated per ASME Section III, 1980. At YNPS, bellows-type expansion jointa seal the penetrations of the concrete Reactor Support Structure (RSS) legs and the Spent Fuel Chute through the VC shell. The RSS expansion joints do not lend themselves to Section III analysis methods; consequently, a code evaluation cannot be made. Each joint. however, is subject to periodic pressure tests and was tested originally to 50 psig. Since the design basis accident pressure for the VC shell is 31.5 psig, the integrity of these expansion joints has been and continues to be demonstrated.
Action No. 2, Re-examine the margins of safety of SSS structures under loads and load combinations which correspond to current criteria. Consider those specific loads and load combinations identified in Section 10 of the TER.
Summary of Results - Action No. 2 Enclosure 2 presents the details of our results for Action No. 2.
Section 10 of the TER identifies: a) current design loads which do not correspond to original YNPS design loads and b) the two most severe load combinations currently specified under emergency and accident conditions by the Standard Review Plan (SRP).
In their TER, FRC identified four design loads which warranted further review. These are seismic, tornado, snow, and pipe reaction loads. The application of seismic loads will be resolved through SEP Topic III-6.
Tornado loads will be resolved through SEP Topic III-2. SEP Topic II-2.A specified the extreme snow load for YNPS. Our letter of September 8, 1986, Reference (d), presented the results of our evaluation of snow loads for YNPS.
The fourth load identified in the TER is that resulting from pipe reaction under accident conditions. AT YNPS, the only structure potentially affected by this load is the VC shell. The consequences of this load applied
United States Nuclear Regulatory Commission December 4, 1986 Attention: Ms. Eileen McKenna Page 4 FYR 86-116 to the VC'shell have been previously evaluated by the staff in Reference (e) and found to be acceptable.
The load combinations that were identified in the TER were compared with the corresponding load combinations which have been used in-our most recent evaluation of each SSS structure. These evaluations were performed as part of the resolution of SEP Topics III-2 and III-6.
Our review for all SSS structures concludes that loads and load combinations have been adequately addressed either in the original plant design or in these recent SEP analyses.
The exception to this is the MS/FW support structure. Yankee Atomic Electric Company (YAEC) has committed to reanalyze and seismically upgrade this structure.
-Action No. 3 Review Appendix A of the TER to confirm that all items listed have no impact on safety margins at YNPS.
Summary of Results - Action No. 3 Our review of Appendix.A of the TER confirmed that the items listed are either not applicable to YNPS or are addressed in Action No. 2 above.
We believe the enclosed summary along with the Reference (d) submittal is sufficient to resolve SEP Topic III-7.B.
It is our understanding that the staff will issue an SER for SEP Topic III-7.B and a summary resolution of this topic in a future supplement to NUREG-0825. If you have any questions on our response, please let us know.
Very truly yours,
^
G. Pap 4 Jr.
Senior Project Engineer - Licensing Yankee Project GP/bil Enclosures
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ENCLOSURE 1 SEP Topic III - 7.B: Code Comparisons Use the following legend for'the matrix beginning on the next page.
- a. In Reference (c), the NRC instructed Yankee to evaluate structures within the SSS scope. The scope of SSS structures is identified in Enclosure 3 of Reference (C). These are listed below and presented in the matrix.
TB = Turbine Building PAB = Primary Auxiliary Building, including the Radioactive Pipe Tunnel MS/FW = Main Steam /Feedwater Support Structure VC = Vapor Container TK-55 = Fire Water Tank SSB = Safe Shutdown System Building RSS = Reactor Support Structure
- b. All structural elements listed in Section 13 of the TER are presented in the matrix. S1, S2, etc., indicate steel elements; C1, C2, etc.,
indicate concrete elements; and M1, M2, etc., indicate VC mechanical / structural elements.
- c. Under each structural element the particular item and corresponding applicable section of the new code are identified. For each structure, the following key applies:
o N/A = This item is not applicable to this structure, o AISC 8th Edition, ACI 318-77, etc., = for t'ais structure, this item has been evaluated and is in conformance with this particular edition of the code.
o Notes 1, 2, etc. are notes located after element C9.
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ENCLOSURE 1 *
(Continued)
AISC Code Comparison STRUCTURAL ELEMENTS STRUCTURES D PAB MS/FW YC TK-55 SSB RSS SI. Beams / Columns o Hollow Circular Sections N/A N/A N/A Meets N/A N/A N/A Subject to Bending AISC (AISC 1.5.1.4.1(7)) 8th Ed.
S2. Composite Construction o Shear Connectors in Composite N/A N/A N/A N/A N/A N/A N/A Beams (AISC 1.11.4) o Composite Beams or Girders N/A N/A N/A N/A N/A N/A N/A with Formed Steel Deck (AISC 1.11.5) o Width of Concrete Fiange N/A N/A N/A N/A N/A N/A N/A Limitations (AISC 1.11.1)
S3. Compression Elements o With Width-to-Thickness N/A N/A N/A N/A N/A N/A N/A Ratio > Specified in AISC 1.9.1.2 (AISC 1.9.1.2 and Appendix C) 1
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ENCLOSURE 1 ;
(Continued)
STRUCTURAL ELEMENTS STRUCTURES TB PAB MS/FW YC TK-55 SSB RSS o Hollow Circular Sections N/A N/A N/A Meets N/A N/A N/A f Subject to Axial Compression AISC {
(AISC 1.9.2.3) 8th Ed.
o Members Where Sidesway is N/A N/A N/A N/A N/A N/A N/A.
Not Prevented (AISC 1.8.3) l l
S4. Tension Members l l
o When Load is Transmitted by Meets Meets Note 1 N/A N/A N/A N/A {
Bolts or Rivets (AISC 1.14.2.2) AISC AISC 8th Ed. 8th Ed.
o Built-Up Members (AISC 1.18.3) Meets Meets N/A N/A N/A N/A N/A j AISC AISC 8th Ed. 8th Ed. .
SS. Connections o Beam Ends with Top Flange Meets Meets Meets N/A N/A N/A N/A Coped, if Subject to AISC AISC AISC Shear (AISC 1.5.1.2.2) 8th Ed. 8th Ed. 8th Ed.
o Connections Carrying Moment N/A N/A N/A N/A N/A N/A N/A or Restrained Member End Connection (AISC 1.15.5.2, 3, 4) l l
ENCLOSURE 1 (Continued)
STRUCTURAL ELEMENTS STRUCTURES D PAB MS/FW C V_C TK-55 SSB RSS S6. Members Designed to Operate in Inelastic Regime o Spacing of Lateral N/A N/A N/A N/A N/A N/A N/A Bracing (AISC 2.9)
S1. Rolled Sections and Built-Up N/A N/A N/A N/A N/A N/A N/A Members (AISC 1.5.1.4.1) o Partial Length Cover Plates N/A N/A N/A N/A N/A N/A N/A (AISC 1.10.4)
S8. Members Subject to Axial Meets Meets Note 1 Meets Meets N/A N/A and Bending Stresses AISC AISC AISC AISC (AISC 1.6) 8th Ed. 8th Ed. 8th Ed. 8th Ed.
S9. Plate Cirder Webs o Subject to Shear and Tension N/A N/A N/A N/A N/A N/A N/A Stresses (AISC 1.10.7); with Stiffeners (ISIC 1.10.10.2)
S10. Partial Penetration Welds o Effective Throat N/A N/A N/A N/A N/A N/A N/A Thickness (AISC 1.14.6.1)
ENCLOSURE 1 (Continued)
ACI Code Comparison STRUCTURAL ELEMENTS STRUCTURES TB PAB MS/FW VC TK-55 SSB RSS C1. Short Brackets and Corbels o Shear Span-to-Depth Ratio of Meets N/A N/A N/A N/A N/A N/A Unity or Less (ACI 11.13) ACI 349-76 C2. Shear Walls l
o Used as Primary Load Meets Meets N/A N/A N/A Meets N/A
- 318-77 318-77 349-76 C3. Precast Concrete Structural Elements o Shear is Not a Measure of Meets N/A N/A N/A N/A N/A N/A Diagonal Tension (ACI 11.14) ACI 349-76 C4. Concrete Regions Subject to High Temperatures I
o Time-Dependent and N/A N/A. N/A N/A N/A N/A Note 2 Position-Dependent Temperature Variations (ACI 349-76, Appendix A) l l
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ENCLOSURE 1 (Continued)
- STRUCTURAL ELEMENTS STRUCTURES TB PAB MS/FW VC TK-55 SSB RSS C5. All Structural Elements o Ultimate Bond Strength Meets Meets N/A N/A N/A Meets Note 3 (ACI 349-76, Chapter 12) ACI ACI ACI 318-77 318-77 349-76 o Allowable Bond Stress Meets Meets N/A N/A N/A Meets Note 3 (ACI 318-56. Table 305(a)) ACI ACI ACI 318-77 318-77 349-76 C6. Columns with Spliced Reinfo"cemreg o Subject to Stress Reversals N/A N/A N/A N/A N/A N/A Note 3 (ACI 349-76, 7.10.3)
C7. SJ eel Embedments o Uced to Transmit Loads to Meets Note 4 Note 1 N/A Meets Meets Meets Concrete (ACI 349-76, Appendix B) ACI ACI ACI ACI
- 318-77 349-76 349-76 318-77 C8. Ele,wnts Subject to Impulsive N/A N/A N/A N/A N/A N/A N/A and Impactive Loads VACI 349"76. Appendix C) s
t ENCLOSURE 1 (Continued)
STRUCTURAL ELEMENTS STRUCTURES TB PAB MS/FW VC TK-55 SSB RSS C9. Composite Construction N/A N/A N/A N/A N/A N/A N/A (ACI 349-76. Chapter 17)
NOTE 1: MS/FW support structure analysis will be performed in the future in accordance with the schedule given to the NRC.
NOTE 2: ACI 349-76, Appendix A, is applicable for:
Normal Operating Temperature (NOT) >150 0 F general and 2000 F local; and Accident temperature >350 F general and 6000F local.
0 YNPS parameters are as follows: NOT (maximum) = 1200F Accident Temp = 2490F (LOCA)
Accident Temp = 3600F (MSLB) exceeds 3000F for 3 minutes NOTE 3: Addressed by seismic analysis of Reactor Support Structure by Cygna Energy Services, Report No. EY-YR-80023-6, Revision 3, dated March 1983.
NOTE 4: To be resolved through confirmatory analysis of the PAB which is being performed under SEP Topic III-6.
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f ENCL 9SURE 1 .
(Continued)
- 7' ASMF Cod _e Comparison n
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Note: Mechanical / Structural Elements M1 through M10 apply only to the Vapor Container (VC). . Js:
. ~ m Ml The Stone and Webster original design specification (YS-289,'~~ r :
ASME Section III, 1980, NE-3112.4 revised December 15, 1959) lists material specifications for each component. No statement for substitutions is given. A review of 1 Q
" Plates, if Understrength" the applicable Chicago Bridge & Iron fabrication drawings for the VC shell shows no other materials were substituted. In 1982,'-
Cygna Energy Services performed a seismic evaluation of the VC-for SEP Topic III-6. They used material allowables based on the 1980 ASME III code for the modern equivalent ASTM cpecification of the materials in the 1956 ASME VIII code.
Therefore, the VC does meet the new code for this element.
M2 Material specifications in ASME III, 1980, for all pressure ASME Section III, 1980, , retaining components in the original design specification for the NE-3112.4 Vapor container and expansion joints are either identical to
" Vessels of Materials ASME VIII 1956 code or an- equivalent current ASTM or ASME No Longer Listed As specification.
Code' Acceptable" '
Therefore, the VC does meet the new code for this element.
M3 Original' design calculations include both design by formula ASME Section III, 1980, (required thickness equations) and analysis for dead load, water, NE-3131 wind, snow, and piping loads. Also, Cygna's seismic evaluation
" Containment Shells used the finite element program, ANSYS, to analyze the entire VC Designed by Formula" shell, penetrations, and supporting structure.
Therefore, the VC does meet the new code for this element.
1 ENCLOSURE 1 (Continued)
ASME Code Comparison M4 There are two stiffener rings on the VC. These are located ASME Section III, inside and outside the VC on the personnel hatch barrel. The 1980, NE-3133.5(a) design of these stiffening rings is such that the stiffening
" Stiffening Rings for provided exceeds ASME Section III NE-3133.5(a) requirements.
Cylindrical Shells Subject to Buckling Loads" Therefore, the VC does meet the new code for this element.
M The stiffening rings described in M4 above are the same material ASME Section III, as the shell.
1980. NE-3133.5(b)
" Shells and Stiffening Therefore. this element is not applicable.
Rings of Different Material" M A fatigue exemption evaluation per ASME III NE-3221.5(d) has been ASME Section III, successfully performed for the VC.
1980. NE-3221.5
" Containment Components Per NE-3221.5(d)1, the allowable number of atmospheric-to-service Subject to Cyclic pressure cycles is 3,500. The actual number to date is 44. For Loadings" this number of service cycles, the maximum allowable AT per NE-3221.5(d) is 7760F. The maximum actual AT (at the main steam penetrations) is 575 0F.
Therefore, the VC does meet the new code for this element.
ENCLOSURE 1
-(Continued)
ASME Code Comparison M1 There are three flat heads on the VC:
ASME Section III, 1980, two-20" diameter manholes and one-18" diameter manhole. None of Figure NE-3325-1 (c) and (m) these are the types shown in ASME III, Figure NE-3325-1 (c) and "Unstayed Flat Heads (m).
and Covers of the Designs in the Therefore this element is not applicable.
Referenced Figures" M8 Subsection NE-3327 of the code states that it applies La ASMR Section III, 1980, " Closures other than multibolted type that are designed to NE-3327 provide access to the contents space of a component..." The
" Quick Acting Closures" personnel hatch of the VC is the only closure to which this applies.
Subsection NE-3327 of the code states the following two specific design requirements for a quick-acting closure:
- 1. " .. Shall have the locking mechanism or locking
. device so designed that failure of any one locking element or component in the locking mechanism cannot result in failure of all other locking elements and the release of the closure."
- 2. " Quick actuating closures shall be so designed and installed that it may be determined by visual external observation that the holding elements are in good condition and that their locking elements are in good condition and that their locking elements, when the closure is in the closed position, are in full engagement."
ENCLOSURE 1 (Continued)
ASME Code Comparison M8 (Continued) The VC Personnel Hatch (VCPH) is equipped with redundant inner and outer doors. These doors are identical in the way they are designed and operated. Each door is also designed to withstand full containment design pressure; therefore, if one door were to fail in the open position, the second door would maintain containment integrity.
The locking devices on each door are also identical. Each door has a series of metal tabs along the outside circumference of the door. The locking device is a rotating j ring, called a locking ring, with metal tabs that align themselves with the tabs on the door. The locking ring is locked in position by a locking pin which is part of a slide bolt handle. The locking pin can only be inserted when the locking ring is completely aligned with the door in the I
locked position.
1
! Therefore, with regards to the first design requirement, two failures are required to open one door. First, the locking J
pin must fail so that the locking ring can be rotated, and i then a second failure is needed to rotate and disengage the locking ring. The locking ring is rotated manually with a set of screwjacks, or hydraulically. The most likely failure to assume would be an inadvertent actuation of the hydraulic control circuit. Since there are two doors, four failures are needed to open the personnel hatch to
! containment.
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ENCLOSURE 1 ,
(Continued)
ASME Code Comparison M8 (Continued) With regards to the second design requirement, the outside door locking ring is visible for inspection from the outside, and must be fully engaged to enable the locking pin to be engaged. The faces of the locking ring and door tabs can only be inspected with the door open. This is required to be checked by procedure, and any abnormal conditions reported to the Control Room. The inner door cannot be inspected until the outer door is opened. The inner door l locking device is verified fully engaged by noting the position of the locking pin. An interlock is provided that prevents the outer door from being opened unless the inner door is closed. In addition, since the containment is maintained at a positive pressure, the personnel hatch must be vented before opening the outer door. This is not done.
until the air flow stops from the vent line. If air continues to come out from the vent line, the inner door is assumed open.
I NE-3327.1 Subsection NE-3327.1 does not apply to manually operated closures
" Positive Locking Devices" such as the VCPH. Subsection NE-3327.3 applies to manually operated closures and will be discussed below.
NE-3327.2 This section does not apply since the VCPH is is the only quick "Other Quick Access access closure into the containment, and Safety Devices" t
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ENCLOSURE 1 (Continued)
ASME Code Comparison M8 (Continued)
NE-3327.3 Subsection NE-3327.3 states: " Quick actuating closures that are
" Manual Operation" held in position by a locking device or mechanism that requires manual operation and are so designed that there will be leakage of the contents of the vessel prior to disengagement of the locking elements and release of closure need not satisfy NE-3327.1 ..." -The VCpH meets these criteria. It is manually operated, and unlocking the locking pin vents the personnel hatch prior to disengaging the locking ring.
NE-3327.3 further states: "... Such closures shall be equipped with an audible or visible warning device that will serve to warn the operator if. pressure is applied to the vessel before the-closure and its holding elements are fully engaged in their intended position and further will serve to warn the operator if an attempt is made to operate the locking mechanism or device before the pressure within the vessel is released.
An indicating light is provided on the VCPH control panel outside containment to indicate that the inner door is fully closed and locked. The indicating light is actuated by a limit switch on the inner door that is adjusted such that the light will not be lit unless the inner door locking pin can be engaged; i.e. , the locking ring must also be fully engaged. The same limit switch also actuates an interlock that prevents opening the outer door with the inner door not fully closed and locked. Also, as discussed previously, disengaging the locking pin vents the area between the two doors while the locking ring is fully engaged.
These three features satisfy the requirements of NE-3327.3.
I ENCLOSURE 1 (Continued) i ASME Code Comparison M8 (Continued)
NE-3327.4 Subsection NE-3327.4 states: "...All vessels having quick
" pressure Indicating actuating closures shall be provided with a pressure indicating i Device" device visible from the operating area." Containment pressure is not indicated at the VCpH control panel. However, as discussed
- above, disengaging the locking pin on the outer door vents the j area between the inner and outer door. If the inner door is not l tightly sealed and a positive pressure exists inside containment, the vent will continue to release air, which warns the operator that the area between the doors is still pressurized.
This arrangement is superior to a pressure gauge since rather j than counting on an indication of the pressure behind the door,
, the pressure is dissipated through the vent. Also, the locking ring remains fully engaged, and is not engaged by the operator
, until the pressure is dissipated.
t Therefore. the VC does meet the new code for this element.
1 i M9 All penetrations in the VC have been evaluated to ASME Section III, ASME Section III, 1980, NE-3334.1 and NE-3334.2 criteria. All 1
1980, NE-3334.1 and NE-3334.2 reinforcement provided meets additional 1980 restrictions.
" Reinforcement for Vessel Openings" Therefore. the VC does meet the new code for this element.
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ENCLOSURE 1 (Continued)
ASME Code Comparison M10 The seals between the VC sttveture and the ASME Section III, Reactor Support Structure (RSS), as well as the seal between the 1980. NE-3365 VC and the Spent Fuel Chute, utilize expansion joint designs.
" Bellows and Bellows The Fuel Chute joint is a bellows type. The RSS joint is of the Expansion Joints" folded / bellows design which does not lend itself to Expansion Joint Manufacturers Association methods of analysis referenced by NE-3365 of ASME Section III.
Per the original specification, the expansion joints have been designed and tested for both pressure and differential displacements. This included pressure testing at 50 psig as well as pressure testing at 40 psig combined with design differential displacements.
The design basis accident pressure for the VC is 31.5 psig.
Technical Specifications require three Type A pressure tests during each 10-year service period. Six separate tests have been performed since 1969 These tests were performed at 17.0, 17.5, 16.5, 31.8. 17.1, and 21.9 psig. In all cases, the containment leakage rates were less than half the allowable rate.
Additionally, VC leakage is continuously monitored.
The norinal containment operating pressure and differential movements are minimal; therefore, stress or fatigue is not a concern. In sununary, the expansion joint tests demonstrate joint design integrity.
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ENCLOSURE 2 SEP Topic III-7.B: Loads and Load Combinations Enclosure 2 concerns loads and load combinations listed in Section 10 of the FRC TER-C5257-316. The TER identifies (a) current design loads which do not correspond to original YNPS design loads, and (b) the two most severe load combinations currently specified under emergency and accident conditions by the Standard Review Plan (SRP) for each structure.
LOAD DEFINITTONS D = Dead load L = Live load, including snow load unless otherwise indicated S = Snow load To = Normal operating thermal loads Ro = Pipe reaction loads (normal operating)
R a = Pipe reaction loads (accident conditions)
YCS = Earthquake loads based on the Yankee Composite Spectra NRC = Earthquake loads based on the NRC Site Specific Spectra Wt = Loads induced by tornado event including differential pressure FL = Hydrostatic loads induced by flooding during a LOCA W = Wind load To = Thermal loads (accident conditions)
Ts = Thermal loads generated by safety relief valve discharge Pa = Pressure load (accident conditions)
Ps = Pressure loads generated by safety relief valve discharge Rs = Pipe reaction loads generated by safety relief valve discharge E, = Operating Basis Earthquake (OBE) load E = Safe Shutdown Earthquake (SSE) loads Yr = Load generated by reaction from pipe break Yj = Jet impingement load from pipe break Ym = Missile impact load from pipe break
i ENCLOSURE 2 (Continued) *
(e) NEW LOADS TO BE ADDRESSED ACCORDING TO THE FRC TER Structure Load Remarks VC Ra The consequences of this load applied to the VC shell have been previously evaluated by the staff in Reference (e) and found to be acceptable.
E' The application of seismic loads will be resolved through SEP Topic III-6. This structure has been evaluated to the NRC Site Specific Spectra and found to be acceptable.
Wt Tornado loads will be resolved through SEP Topic III-2. This structure has been analyzed for a 248 mph wind load and found to be acceptable.
TB S SEP Topic II-2.A specified the extreme snow load. This was evaluated and the response was submitted via Reference (d).
PAB S See TB.
RSS - -
TK-55 S See TB.
MS/FW - -
ENCLOSURE 2 ,
(Continued)
(b) LOAD COMBINATIONS Structure Identified by FRC Evaluated by YAEC Remarks VC (1) D+L+Ta+Ts+Pa (a) D + L + To + YCS The load Ra used by YAEC includes
+ Ps + Ra + Rs + E' (b) D + L + To + NRC dead, thermal, and seismic loads.
+ Yr +Yj + Ym (c) D + L + Ta + Pa + FL + YCS + Ra The loads Ts and Ps are bounded by the loads Ta and Pa used by YAEC. The load Rs is not applicable to the VC. The loads Yp , Yj, and Y,are not applicable to the VC; refer to SEP Topic III-5.a. Load combination (c) is applied only to the VC shell pipe penetrations.
(2) D+L+FL+E (d) D + L + Ta+Pa+FL The staff has previously accepted the position that seismic and LOCA loads are decoupled. Therefore, E, the seismic OBE, should not be combined with Fg hydrostatic loads induced by flooding during a LOCA.
TB (1) D+L+To+Ro+Wt (a) D+L+To+Ro+W Critical components of this structure have been evcluated for W,
t tornado wind loads, under SEP Topic III-2.
(2) D+L+Ta+Pa+Ra (b) D+L+To+Ro + YCS Loads Ta , Pa , and Ro are
+ E' +Yr + Yj + Ym insignificant for this structure.
Loads Y r , Yj, and Ymhave been resolved through SEP Topic III-5.B.
ENCLOSURE 2 ,
(Continued)
(b) LOAD COMBINATIONS (Continued)
Structure Identified by FRC Evaluated by YAEC Remarks PAB (1) D+L+To+Ro+Wt (a) D + L + Ro+W To loads are insignificant.
Critical components of this structure have been evaluated for W t, tornado wind loads, under SEP Topic III-2.
(2) D+L+Ta+Pa+Ra (b) D+Ro + YCS Loads Ta , Pa , and Ra are
+ E' +Yr + Yj + Ym (c) D+Ro + NRC insignificant for this structure.
Loads Yr = Yj, and Ym have been resolved through SEP Topic III-5.B.
.