ML19282B448
| ML19282B448 | |
| Person / Time | |
|---|---|
| Site: | Zimmer |
| Issue date: | 02/01/1979 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Borgmann E CINCINNATI GAS & ELECTRIC CO. |
| References | |
| NUDOCS 7903150022 | |
| Download: ML19282B448 (12) | |
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[{*l-UNITED STA Os
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NUCLEAR REGULATOFfY cOM V 1, d
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FEB 1 M9 Docket No. 50-358 Mr. Earl A. Borgmann Vice President - Engineering Cincinnati Gas & Electric Company P. O. Box 960 Cincinnati, Ohio 45201 Dedr Mr. Borgmann:
SUBJECT:
LEAD PLANT MARK II ACCEPTANCE CRIYERIA (Wm. H. Zimmer Nuclear Power Station, Unit 1)
In our letter to you dated September 14, 1978, we identified certain generic criteria for the lead plants that we find acceptable.
The bases for these criteria are discussed in NUREG 0487, dated October 1978.
To complete our safety evaluation of your application for the Zimmer Nuclear Power Project, we need to know the extent of your commitment to adopt these criteria.
Your FSAR for Zimmer should be amended to identify those criteria that you are committing to adopt.
The applicants for the lead Mark II plants have identified a numoer of areas where they propose to take exception to our criteria.
Alternative criteria were to be proposed by the fiark II owners in each of these areas.
In this regard, several meetings were conducted in November and December 1978 between the NRC and the applicants for the lead plants to discuss the alternative criteria and their supporting bases.
At these meetings, the staff identified certain additional information that would be required to support the alternative criteria proposed by the lead plant applicants.
The status of our review for each of these items, including a summary description of the additional information required by the staff is provided.in Enclosure 1.
We need your schedule for pro iding this informa tion.
Two additional enclosures are provided that relate to pool dynamic concerns that should also be resolved by the lead plant applicants.
The first of these, Enclosure 2, consists of questions raised by the staff dealing with the lead plant applicants at the August 15, 1978 meeting. We have not received a response to these questions. is provided to clarify the staff's position with regard to Load Case 10.
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i FCC 1 1979 Mr. Earl A. Borgmann We will need your response to this letter including identification of the -
criteria that you will comit to, your program to provide information to support alternative criteria and your schedule for responding to our questions.
This information should be submitted no later than February 9, 1979, to meet our current review schedule.
Please contact us if you have any questions regarding this matter.
Sincerely, John F. Stolz, Chief
.ight Water Reactors rar ch No.1 Division of Project Management
Enclosures:
As stated cc:
See page 3
FEP' 1 1973 Mr. Earl A. Borgmann
- cc:
Troy B. Conner, Jr., Esq.
David B. Fankhauser, PhD Conner, Moore & Corber 3569 Nine Mile Road 1747 Pennsylvania Avenue, N. W.
Cincinnati, Ohio 45230 Washington, D. C.
20006 Thomas A. Luebbers, Esq.
Mr. William J. Moran Cincinnati City Solicitor General Counsel Room 215, City Hall The Cincinnati Gas and Electric Cincinnati, Ohio 45202 Company P. O. Box 960 Mr. Stephen Schumacher Cinnati, Ohio 45201 Miami Valley Power Project P. C. Box 252 Mr. William G. Porter, Jr.
Dayton Ohio 45401 Porter, Stanley, Arthur and Platt Ms. Augusta Prince, Cnairperson 37 West Broad Street 601 Stanley Avenue Columbus, Ohio 43215 Cincinnati, Ohio 45226 Mr. Peter H. Forster, Vice President Charles Bechhoefer, Esq., Chairman Energy Resources Atomic Safety & Licensing Board The Dayton Power and Light Panel Company U. S. Nuclear Regulatory Commission P. O. Box 1247 Washington, D. C.
20555 Dayton, Ohio 45401 J. Robert Newlin, Counsel The Dayton Power and Light Company P. O. Box 1247 Dayton, Ohio 45401 Mr. James D. Flynn Manager, Licensing Enviror,aental Affairs The Cincinnati Gas and Electric Company P. O. Box 960 Cincinnati, Ohio 45201 Mr. J. P. Fenstermaker Senior Vice President-0perations Columbus and Southern Ohio Electric Company 215 North Front Street Columbus, Ohio 43215
Information !!equest Lead Plant Load Acceptance Criteria 1.
Pool Swell Elevation and Wetwell Air Compression (I.B.I.b, I.B.l.e and I.B.4.a)*
A meeting was held with the fiark II Owners Group on flovember 14, 1978 to discuss an alternative approach to our criteria. We concluded that this approach was acceptable. We request documentation from the fiark II owners, to include a description and justification for this new methodology.
2.
Small Structure Impact Loads (I.B.3.a)
The fiark II owners stated that they would take exception to this criterion at our meeting with them on October 19, 1978.
A summary description of their revised methodology was presented at this meeting.
Insuffi*nt information was provided for us to conclude on the acceptability of the revised methodology.
We request documentation from the fiark II Owners, to include a description and justification for this new methodology.
- Load designation based on Load Summary Table and Acceptance Criteria in letter dated September 14, 1978 from R. S. Boyd to lead flark II plants.
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- 2 3.
Asymmetric Pool Swell Loads (I.B.5)
At the October 19, 1978 meeting, the Mark II owners stated their intentions of sending the staff a letter report to include a description and a justification of a more realistic asymnetric pool swell load. We have not received any additional information since that meeting.
4.
Submerged Boundary Load During Vent Clearing (I.A)
At the October 19, 1978 meeting, the Mark II owners stated their intentions of sending the staff a letter report to include justification for either neglecting or reducing this load for the containment walls. We have not received any additional information since that meeting.
5.
LOCA/SRV Submerged Drag Loads (III)
Several discussions have been conducted with the Mark II owners to investigate potential alternatives to the staff's criteria.
These meetings were held on October 19 and November 15, 1978. The staff stated that in several areas deviations from our criteria appeared acceptable.
However, additional information was required.
This additional information includes the following:
- Justification for neglecting the acceleration drag loads associated with the LOCA water jet;
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- A description of the ring vortex model;
- Unpublished data of Sarpkaya for acceleration drag coefficients in a non-oscillating flow field;
- The results of sensitivity studies to justify selection of an equivalent velocity and acceleration for drag calculations in a uniform flow field.
- Generic guidelines for establishing interference effects in drag calculations for closely spaced structures.
- A description of the zone of influence to be utilized for "T"
quencher jet loads and a description of the experimental program to confirm this zone of influence.
6.
SRV Bubble Phasing (II.B.G)
We find that the method proposed by the Mark II owners at the December 13, 1978 meeting meets the intent of our criteria.
- However, some questions exist regarding the detailed methodology for calculating bubble phasing and load combination from each SRV line.
We have had discussions with Sargent and Lundy.
They have agreed to provide information through the Mark II program to resolve our questions.
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7.
SRV Bubbie Frequency (II.B.C)
The method proposed by the Mark II owner at the December 13, 1978 meeting does not meet our criteria.
This method utilizes a broadening of the response spectrum to account for uncertainties in the frequency of the SRV load specification.
Bubble frequency is a critical component of the SRV load specification.
It is important that the lead plants provide either an acceptable SRV frequency specification with justification or commit to our criteria as soon as possible.
8.
Chugging FSI Effects The staff concluded in the Mark II Load Evaluation Report that the Mark II owners chugging load specification was acceptable but that additional analyses of the 4T results should be performed to resolve several staff questions related to FSI effects.
These questions were discussed with the Mark II owners at a meeting on August 15, 1978 (See Enclosure 2).
We have not received any information from the Mark II owners, since that meeting to resolve our questions.
9.
Load Combinations - Load Case No.10 The Mark II owners stated that this load case would be applied to only the containment. Our position is that the load case also be applied to piping and equipment. A clarification of our position is provided in Enclosure 3.
Questions and Comments on Chus Inoulse Letter Report (June 1978) 1)
Integratito of the wall pressures yields " impulses" on the order of 0.05-0.10 psi-sec (Table 3-1).
The values of " impulse" to be applied at the vent are on the order of 0.3 psi-sec.
Provide a detailed description of the procedure used to derive the latter from the former.
2)
T V.3 results presented in Table 3-1 indicata negative and/or no correlation betocen chug over/under/ pressure and the corresponding values of chug
" impulse" (i.e.:
meximum "impulsa" is associated with mintaan overpres-sure etc.).
Ccemenc on this apparent ancanaly.
3) 7he chug pressure-time histories used for most of the calculations which are pri: stated (-56 osiW.10 usec) imply negative absolute pressure (local hydrostatic in Run 55 is approximately 3 atm. + 11 foot sutwr-gence== 50 psi).
Cr=-nt on this pitysical inconsistency.
4)
The proposed impulse duration cvf 10 usec is approximately 30% of the na-tural period of the 4T water-tank system.
This is too high by about a f actor of three to justify the notion that the loading is " impulsive" (shape of pulse not itaportant).
Provide additional justification for the use of the proposed pulse shape.
5)
The various plots of pressure history generated by the Anamet model (e.g.:
Figure S-f3 ) suggest that the calculations were performed with an tmpres-surized wetwell.
Coannent on what effect canission of this additional pres-sure has on the final results.
6)
As indicated in Figure 1-1, a vital link in the argument for the correct-ness of the " Improved Chugging Load Definition" is the crinparison of re-sponse, i.e.:
ccusparison of the total pressure at the 4T tank / water interface from the model with actual 4T test data.
Such a ccznparison has not been included in this report.
Provide a comparison between theory and experiment for the bottom center pressure.
7)
The 4T bottom center pressure histories from the Anamet calculation and the 4T experiments should also be ccmpared to the corresponding pressure history con 4>uted using the "Bedrosian" methodology ( Anamet rigid incident wall pressure as input) to demonstrate that the Anamet and Bedrosian ccum-putation schernes are equivalent.
B)
Provide the basis for the particular choice of damping used fer the Lead Plant 4T Chugging Load Time History shown in Figure 4-4.
9)
The justification for considering the 4T observed boundary loads as con-servative for Mark 11 application rests primarily on a qualitative geo-metric argtment (bigger pool-to-vent area ratio will redu.a boundarv loads for same intensity chup).
Deconstrate the validity of this argmt quantitatively by performing additional calculations wf th the Anamet methodology for a ~4T-like" configuration but with a larger tank diameter.
Again, eghasis shall be on presentation of bottom center pr_es_sure.
UNITED TATES y*
NUCLEAR REGULATORY COMMISSION j
WASHINGTON, D. C. 20555
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_7-MEMORANDUM FOR:
W. R. Butler, Chief, Containment Systems Branch, DSS G. C. Lainas, Chief, Plant Systems Branch, D0R FROM:
C. J. Anderson, Containment Systems Branch, DSS C. I. Grimes, Plant Systems Branch, D0R
SUBJECT:
P0OL DYNAMIC LOAD COMBINATIONS FOR CONTAINMENT AND PIPING SYSTEMS - LOAD CASE 10 A meeting was held on December 11, 1978 to discuss the staff's positiore related to Load Case No.10 for the Mark II Acceptance CriNria.
This load case specifies that DBA pool swell loads be considered concurrent with SRV and SSE loads. The purpose of the meeting was to discuss our position in light of the staff's position related to this load case for the Mark I and III containment designs. Representatives of CSB, MEB, SEB of DSS and PSB of 00R were present.
As a result of this meeting we developed the following infomation to clarify our position with regard to the Mark II generic and lead plant programs and the corresponding positions for the Mark I and III contair. ment designs.
Generic Position on Load Case No.10 for Mark II Plants:
DBA+ SRV + SSE The staff requires that an evaluation be made of the Mark II containment system for this load case.
This evaluation shall include the critical piping and equipment in the containment (wetwell and drywell) and the reactor cuilding unless it can be shown that no significant dynamic loads are transmitted to these areas.
It is our judgement that a case can be made to limit the SRV actuation to one valve based on " spurious" actuation.
However, although we do not believe that any SRVs can mechanistically actuate following a DBA, we require that the Mark II owners provide confimatory analyses in this regard.
These analyses for the DBA should include consideration of the uncertainties associated with the calculated reactor pressure response and the uncertainty associated with the pressure required for SRV actuation (e.g., set point drift).
Contact:
C. Anderson, 27711 C. Grimes, 28077
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W. R. Butler JAN 5 1979 G. C. Lainas As a minimum, we will require consideration of a single, spuriously-actuated SRV concurrent with the pool swell loads associated with a DBA.
Should the confirmatory reactor system response analyses indicate that there is a potential for mechanistic actuation of the SRVs following a DBA, we will reassess our position.
Load Case No. 10 for the Lead Mark II Plants We require that the applicants for the lead plants evaluate their containment, critical piping and equipment based on Load Case No. 10 considering actuation of one SRV and the DBA.
Th'is evaluation should be completed prior to operation of the plant.
It is our judgement that the reactor pressure transient associated with a DBA would not result in the actuation of more than one SRV.
However, we believe that confinnatory analyses should be provided, as described in our generic position above, to confinn that a DBA would not result in either single or multiple SRV actuat ions.
Load Case No.10 for Mark I and Mark III Plants D0R has taken a position which requires the consideration of a single SRV concurrent with the DBA and SSE loads for the Mark I Long Term Program (LTP). The structural acceptance criteria for the load combination vary based on the extent of reactor system response analyses provided to support the non-mecha-istic nature of the event.
The scope of the LTP is limited to the torus and attached piping.
00d does not consider it necessary to extend this load combination to other structures or components due to the inherent decoupling of the torus and drywell, unique to the Mark I design.
Our position for the Mark III design is the same as our generic position for the Park II contai -ent.
Clifford J. Anderson Christopher I. Grimes Containment Systems Branch Plant Systems Branch Division of Operating Reactors Division of Operating Reactors cc:
see page 3
W. R. Butler G. C. Lainas cc:
R. Tedesco J. Knight F. Schauer R. Bosnak J. Kudrick A. Hafiz C. Grimes T. Su S. Hou C. Anderson R. Satterfield O
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LOAD CASE NO. 10 POSITION - MARK Il PLANTS Generic _ Position on Load Case No. 10 for Mark II Plants: DBAt SRV + SSE TL
'or'f requires that an evaluation be made of the Mark Il containment system for this load case. This evaluation shall include the critical piping and equipment in the containment (wetwell and drywell) and the reactor building unless it can be shown that no significant dynamic loads are transmitted to these areas.
It is our judgement that a case can be made to limit the SRV actuation to one valve based on " spurious" actuation.
However, although we do not believe that any SRVs can mechanistically actuate following a DBA, we require that the Mark II owners provide confirmatory analyses in this regard.
These analyses for the DBA should include consideration of the uncertainties associated with the calculated reactor pressure response and the uncertainty associated with the pressure required for SRV actuation (e.g., set point drift).
As a minimum, we will require consideration of a single, spuriously-actuated SRV concurrent with the pool swell loads associated with a DBA. Should the confirmatory reactor system response analyses indicate that there is a potential for mechanistic actuation of the SRVs following a DBA, we will reassess our position.
Load Case No. 10 for the Lead Mark II Plants We require that the applicants for the lead plants evaluate their containment, critical piping and equipment based on Load Case No.10 considering actuation of one SRV and the DBA.
This evaluation should be completed prior to operation of the plant.
It is our judgement that the reactor pressure transient associated with a DBA would not result in the actuation of more than one SRV.
However, we believe that con-firmatory analyses should be provided, as described in our generic position above, to confirm that a DBA would not result in either single or multiple SRV actuations.
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