ML19284A407

Responds to Encl 1 & 2 of NRC 790201 Ltr Re Lead Plant Mark II Acceptance Criteria

ML19284A407
Person / Time
Site:	Zimmer
Issue date:	03/02/1979
From:	Borgmann E CINCINNATI GAS & ELECTRIC CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
NUDOCS 7903060248
Download: ML19284A407 (14)

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'2 uliG-THE CINCINNATI GAS & ELECTRIC COMPANY cn- --

CIN CINN ATI. OHIO 4 52o1 E. A. BoRGMAN N v4C E PRE SrDENT Docket No. 50-358 March 2, 1979 Mr. Harold Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Contission dashington, D.C. 20555 RE: WM. H. ZIMMER INCLEAR PO!.ER STATION -

UNIT 1 - RESPONSE TO NRC LEAD PLANT MARK II QUESTIONS

Dear Mr. Denton:

In reply to Mr. John F. Stolz's letter of February 1, 1979 to Mr. E. A. Borgmann regarding Lead Plant Mark II Acceptance Criteria, there are attached our responses to the questions raised in Enclosure 1 of that letter and the Zimmer Position on Acceptance Criteria in response to Enclosure 2 of the same letter.

Very truly yours, THE CINCINNATI GAS & ELECTRIC COMPANY 6 'l W "

E. A. BORGMANN Vice President - Engineering Services and Electric Production EAB: dew Enclosure cc: Charles Bechhoefer State of Ohio )

Glenn O. Bright County of Hamilton)ss Frank F. Hooper Sworn to and subscribed before me this Troy B. Conner, Jr.

James P. Fenstermaker o2M day of March, 1979.

Peter H. Forster William J. Moran J. Robert Newlin William G. Porter, Jr.

James D. Flynn '

Thomas A. Luebbers N -

Leah S. Kosik j Notary Public V John D. Woliver VIRG!N!A P. f.iUHLHOFER fictary PuMic, State Of Ohio f4 Commissica Erpires July 28,1932 7903000pijg

ZIMMER RESPONSES NRC MK II CRITERIA JOHN STOLZ FEBRUARY 1, 1979 LETTER TO EARL A. BORGMANN

1. ObESTICN:

POOL SWELL ELEVATION AND WETWELL AIR COMPRESSION (I.B.l.b, I.B.l.e and I.B.4a)*

A meeti.a was held with Mark II Owners Group on November 14, 1978 to cic:ues an alternative approach to our criteria. We concluded that this approach was acceptable. We request docc mentation from the Mark II Owners, to include a description and justification for this new methodology.

RESPONSE

Zimmer Station has agreed to use the NRC criteria. See attached sheet which summarizes Zimmer position on all NRC MK II Acceptance Criteria.

2. QUESTION:

SMALL STRUCTURE IMPACT LOADS (I.B.3a)

The Mark II Owners stated that they would take exception to this criteria at our meeting with them on October 19, 1978.

A summa ry descriptien of their revised methodology was pre-sented at this meeting. Insufficient information was provided for us to conclude on the acceptability of the revised methodology.

We request documentation from the Mark II Owners, to include a description and justification for this new methodology.

RESPONSE

Although extremely conservative, Zimmer Station has agreed to use the NRC criteria. See attached sheet which summarizes Zimmer position on all NRC MK II Acceptance Criteria.

3. QUESTION:

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 asymmetric pool swell load. We have not received any additional information.

3. (cont ' d)

RESPONSE

Although the NRC's Asymmetric Load is very conservative pre-liminary assessments indicate the Zimmer containment can tolerate the proposed pressure unbalance. A letter report on the Zimmer evaluation will be provided shortly. The MK II Containment Program will be submitting documentation to justify removal of unnecestary conservatisms during March, 1979.

4. QUESTION:

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.

RESPONSE

It should be noted that Zimmer can accommodate the NRC criteria.

The suppression pool is designated to withstand 45 psi loading.

A letter report on the Zimmer capability will be provided shortly.

However, it should be noted that the 33 psi is a very conserva-tive estimation of jet loads which should be applied only to the basemat in accordance with DFFR Rev. 2.

5. QUESTION:

LOCA/SRV SUBMERGED DRAG LOADS 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, 1978 and November 15, 1978. The staff stated that in several areas deviations from our criteria appeared acceptable. However, additional informa-tion was required. This additional information includes the following:

Justification for neglecting tta acceleration drag loads associated with tne 'OCA water Jet:

RESPONSE

These loads were not neglected in the Zimmer Platt evaluation.

5. (cont ' d)

QUESTION:

A DESCRIPTION QF THE RING VORTEX MODEL:

RESPONSE

The ring vortex model has been discussed with the NRC since this question set was drafted. A draft write-up on the model was left with the NRC by the MK II Owners Group during the February 13 & 14 MKII/NRC meetings.

In order to expedite the Zimmer Licensing, Zimmer used the NRC criteria and determined that the plant can accommodate predicated loads. It should be pointed out that certain modifications had to be made in the model to overcome math problems. This will be discussed in a letter report to be issued shortly.

QUESTION:

UNPUBLISHED DATA OF SARPKAYA FOR ACCELERATION DRAG COEFFICIENTS IN A NON-OSCILLATING FLOW FIELD:

RESPONSE

This data was developed under the MK II generic program and therefore is not under the sole control of Zimmer project.

Zimmer will however try to expedite.

QUESTION:

THE RESULTS OF SENdITIVITY STUDIES TO JUSTIFY SELECTION OF AN EQUIVALENT VELOCITY AND ACCELERATION FOR DRAG CALCULATIONS IN A UNIFORM FLOW FIELD:

RESPONSE

This work is being developed under the generic MK II Program and therefore is not under the sole control of Zimmer Project.

Zimmer will try to expedite the effort. Current estimates indicate submittal in 2 months.

QUESTION:

GENERIC GUIDELINES FOR ESTABLISHING INTERFERENCE EFFECTS IN DRAG CALCULATIONS FOR CLOSELY SPACED STRUCTUPE.?-

RESPONSE

This effort has been discussed with the NRC in MK II meetings.

It is being developed under the generic MK II Program and there-fore is not under the sole ecntrol of Zimmer Project. Zimmer will try to expedite the erfort.

_4

5. (cont'd)

QUESTION:

A DESCRIPTION OF THE ZONE INFLUENCE TO BE UTILIZED FOR "T" QUENCHER JET LOADS AND A DESCRIPTION OF THE EXPERIMENTAL

,FROGRAM TO CONFIRM THIS ZONE OF INFLUENCE: _

RESPONSE

This matter has been discussed with the NRC. We feel, as a result of those discussions, that 5 feet was suggested as a conservative estimate for preliminary assessment. Although others may pursue a smaller more realistic zone of influence, we would like to point out that Zimmer Station has nothing within the suggested 5 foot zone. We believe this issue there-fore is resolved for Zimmer.

6. QUESTION:

SRV BUBBLE PHASING (II.B.6)

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 & Lundy. They have agreed to provide information through the Mark II program to resolve our questions.

RESPONSE

Additional meetings have since been held with the NRC. We believe the questions have been resolved.

7. QUESTION:

SRV BUBBLE 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.

RESPONSE

Additional discussions have sinca been held with the NRC on a lead plant basis. Although we recognize the bubble frequency is a critical component of the SRV load specification, we believe sufficient information has been discussed to justify proceeding with plant licensing contingent upon confirmatory in-plant SRV test. A lead plant generic (LaSalle, Shoreham, Zimmer) letter report will be submitted in March, 1979.

-S-

8. QUESTION:

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 per-formed to resolve several staff questions related to FSI effects.

These questions were discussed with 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 question.

RESPONSE

Zimmer Station has taken a bounding loads approach to chugging loads which we believe provides adequate margin to cover any FSI uncertainty. Zimmer licensing therefore should proceed with confirmation in the MK II generic program.

The responses to the questions discussed at the August meeting will be documented in the MK II Owners Group in March, 1979.

9. QUESTION:

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.

RESPONSE

The MK II Owners have always felt this load case to be unrealistic, but agreed to accept it for the containment to expedite licensing.

The MK II Owners Group discussed this matter in more detail with the NRC during the February 13 & 14 MKII/NRC meetings.

NRC ACCEPTANCE CRITERIA FOR MKII ZIMMER POSITION

• LOAD OR ON PHENOMENON NRC CRITERIA ACCEPTANCE CRITERIA LOCA-RELATED HYDRODYNAMIC LOADS A. SUBMERGED BOUND 7.RY MKII SPEC. ACCEPTABLE DURING VENT EXTREMELY CLEARING CONSERVATIVE B. POOL SWELL LOADS

1. POOL SWELL ANALYTICAL MODEL

a. AIR BUBBLE MKII SPEC.

PRESSURE

b. POOL SWELL NRC CRITERIA I. A.1 ACCEPTABLE ELEVATION .

c. POOL SWELL NRC CRITERIA I. A.2 ACCEPTABLE VELCCITY EXTREMELY CONSERVATIVE

d. POOL SWELL MKII SPEC.

ACC.

e. WETWELL AIR MKII SPEC.

COMPRESSION

f. DRYWELL ACCEPTABLE IF BASED ACCEPTABLE PRESSURE ON NEDM-10320.

OTHERWISE PLANT UNIQUE REVIEWS REQUIRED.

2. LOADS ON MKII SPEC.

SUBMERGED BOUNDARIES

3. IMPACT LOADS

a. SM. STRUCT. NRC CRITERIA I . A. 6 ACCEPTABLE EXTREMELY CONSERVATIVE e

i .

NRC ACCEPTANCE CRITERIA FOR MKII ZI.WER POSITION

• LOAD OR ON PHENOMENON NRC CRITERIA ACCEPTANCE CRITERIA

b. LARGE PLANT UNIQUE ACCEPTABLE STRUCT. REVIEW WHERE APPLICABLE NRC CRITERIA I.A.3

c. GRATING NRC CRITERIA I.A.3 ACCEPTABLE

4. WETWELL AIR COMPRESSION

a. WALL LOADS MKII SPEC.

b. DIAPHRAGM NRC CRITERIA I.A.4 ACCEPTABLE UPWARD LOADS

5. ASYMMETRIC NRC CRITERIA I.A.5 ZI. TIER CAN ACCOMMODATE MKII GROUP WORKING TO DEMONSTRATE NRC

-EXCESSIVELY CON-SERVATIVE-C. STEAM COND. -

AND CHUGGING LOADS

1. DOWNCOMER LATERAL LOADS

a. SINGLE VENT NRC CRITERIA I.B.1 ACCEPTABLE LOADS

b. MULTIPLE NRC CRITERIA I.B.2 ACCEPTABLE VENT LOADS

NRC ACCEPTANCE CRITERIA FOR MKII ZIMMER POSITION

• LOAD OR ON PHENOMENON NRC CRITERIA ACCEPTANCE CRITERIA

2. SUEMERGED BOUNDARY LOADS

a. HIGH STEAM FLUX LOADS MKII SPEC.

b. MEDIUM STEAM FLUX LOADS MKII SPEC.

c. CHUGGING ACCEPTABLE PENDING LOADS RESOLUTION OF FSI CONCERNS.

SRV-RELATED HYDRODYNAMIC LOADS A. POOL TEMPERATURE NRC CRITERIA II.1 ACCEPTABLE LIMITS FOR KWU AND AND II.3 ZIMMER WILL PER-GE FOUR ARM QUENCHER FORM IN PLANT SRV.

TESTS B. QUENCHER AIR CLEARING NRC CRITERIA II.2 UNDER REVIEW:

LOADS

- WIDE RANGE DISCHARGE FREQ. WERE

, CONSIDERED

- BUBBLE PHASING REQUIREMENTS WERE DISCUSSED AND WE BELIEVE RESOLVED WITH NRC

- MKII PROGRAM PRE-SENTED LEAD PLANTS EVALUATION SHOWING RAMSHEAD BOUNDS .

QUENCHER LOADS C. QUENCHER TIE-DOWN LOADS - IN-PLANT CONFIRMATORY TEST PLANNED

1. QUENCHER ARM LOADS

a. FOUR ARM MKII SPEC.

QUENCHER NRC ACCEPTANCE CRITERIA FOR MKII ZIMMER POSITION

• LOAD OR ON PHENOMENON NRC CRITERIA ACCEPTANCE CRITERIA

b. KWU T REVIEW CONTINUING ACCEPTABLE QUENCHER THESE LOADS WILL BE CALCULATED USING THE METHODOLOGY AND ASSUMPTIONS DESCRIBED IN DFFR FOR FOUR ARM QUENCHERS, AS RECOMMENDED IN THE ACCEPTANCE CRITERIA.

2. QUENCHER TIE-DOWN LOADS

a. FOUR-ARM MKII SPEC.

QUENCHER

b. KWU "T" REVIEW CONTINUING ACCEPTABLE QUENCHER THESE LOADS WILL BE CALCULATED USING THE METHODOLOGY AND ASSUMPTIONS DESCRIBED IN DFFR FOR FOUR ARM QUENCHERS, AS -

RECOMMENDED IN THE ACCEPTANCE CRITERIA.

LOCA-SRV SUBMERGED STRUCTURE LOADS A. LOCA/SRV JET LOADS

1. LOCA/RAMSHEAD NRC CRITERIA ' UNDER REVIEW:

SRV JET LOADS III.A.1

- LEAD PLANT APPROACH DEVELOPING MORE DETAILED MODEL

2. SRV-QUENCHER NRC CRITERIA RESOLVED JET LOADS III.A.2 DISCUSSED WITH NRC ZIMMER HAS NO STRUC-TURES WITHIN AGREED UPON 5 FT. ZONE OF INFLUENCE NRC ACCEPTANCE CRITERIA FOR MKII ZIMMER POSITION

• LOAD OR ON PHENOMENON NRC CRITERIA ACCEPTANCE CRITERIA B. LOCA/SRV AIR BUBBLE DRAG LOADS

1. LOCA AIR BUBBLE NRC CRITERIA UNDER REVIEW:

LOADS III .B .1

- LEAD PLANT APPROACH BEING DEVELOPED NRC CRITERIA NOT APPLICABLE

2. SRV-RAMSHEAD AIR BUBBLE LOADS III.B.2 s ZIMMER USES -

T. QUENCHER

3. SRV-QUENCHER AIR NRC CRITERIA QiDER REVIEW:

BUBELE LOADS III.B.3

- CRITERIA REQUIRES MODIFICATION FOR TEE QUENCHER GEOMETRL METHODS

. DISCUSSED WITH NRC 12-12-70 LEAD PLANT LOAD ACCEPTABLE C. STEAM CONDENSATION ZIMMER RESULTS DRAG LOADS SPECIFICATION AND NRC REVIEW WILL PRESENTED IN BE CONDUCTED ON A CLOSURE REPORT PLANT UNIQUE BASIS PORTION OF FSAR WITH CONFIRMATION IN LONG TERM PROGRAM USING GENERIC MODEL.

SECONDARY LOADS A. SONIC WAVE LOAD MEII SPEC.

B. COMPRESSIVE WAVE MKII SPEC.

LOAD PLANT UNIQUE LOAD ACCEPTABLE C. POST SWELL WAVE LOAD SPECIFICATION AND NRC REVIEW PLANT UNIQUE LOAD ACCEPTABLE D. SEISMIC SLOSH LOAD SPECIFICATION AND NRC REVIEW.

5

A ,', ,

.n NRC ACCEPTANCE CRITERIA FOR MKII ZIMMER POSITION

• LOAD OR ON PHENOMENON NRC CRITERIA ACCEPTANCE CRITERIJJ E. FALLBACK LOAD ON MKII SPEC.

SUBMERGED BOUNDARY F. THRUST LOADS MKII SPEC.

G. FRICTION DRAG LOADS MKII SPEC.

ON VENTS H. VENT CLEARING LOADS MKII SPEC.

FUNCTIONAL CAPABILITY INTERIM TECHNICAL ACCEPTABLE POSITION (7-19-78)

MASS-ENERGY RELEASE VERIFY USING RELAP4/ ACCEPTABLE FOR ANNULUS PRESS. MOD 5 QUESTIONS 15% PEAK BROADENING TO ACCEPTABLE SEB-2, MEB-5 BE.USED.

SEB-3, MEB-5 CLOSELY SPACED MODES ACCEPTABLE. NSSS COMBINED PER 1.92. SCOPE USED MODIFIED SUMMATION PER APPROVED GESSAR.

MEB-1 DYNAMIC ANALYSIS ACCEPTABLE METHODS ACCEPTABLE MEB-2 OBE DAMPING - LEVEL ACCEPTABLE A OR B SSE DAMPING - LEVEL MEB-6 C OR D MEB-6 SEISMIC SLOSH-PLANT ACCEPTABLE UNIQUE REVIEW MEB-7a & b LOAD COMBINATIONS: ACCEPTABLE AP+SSE OBE+SRV SEE LOAD COMBINATION TABLE FOR CASE #2 & 7 MEB-8 FUNCTIONAL CAPABILITY SEE LOAD AND PIPING ACCEPTANCE COMBINATION TABLE CRITERIA IN D.A.R.

/ .

. r.

NRC ACCEPTANCE CRITERIA FOR MKII ZIMMER POSITION

• LOAD OR ON PHENOMENON NRC CRITERIA. ACCEPTANCE CRITERIA

1. N+SRVx TO B ACCEPTABLE

2. N+SRVx + OBE TO B ACCEPTABLE -

APPROVED GESSAR APPROACH USED FOR NSSS.

3. N+SRValL+SSE TO C ACCEP'l" BLE

4. N+SRVads+0BE+IBA TO C ACCEPTABLE

5. N+SRVads+0BE+IBA TO C ACCEPTABLE

6. N+SRVads+SSE+IBA TO C ACCEPTABLE

7. N+SSE+DBA TO C ACCEPTABLE

8. N TO A ACCEPTABLE .

9. N+0BE TO B ACCEPTABLE

10. N+SRV +SEE+DBA TO C ACCEPTABLE IF APPLIES TO CONTAINMENT ONLY (SEE M 020.22 &

DFFR 5.2.4)

• Zimmer positions developed based upon NRC acceptance of SRSS for combination of dynamic loads which meet the Newmark/ Kennedy criteria. Although the official licensing basis for Zimmer remains SRSS,Zimmer has provided the NRC with evaluations to demonstrate ABS capability. Specific exceptions to ABS are being justified on a case by case basis.

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