ML20236Y440

Summary of Site Audit & 810609-11 Meeting W/Util Re Response to IE Bulletin 80-11 on Masonry Walls.Lists of Attendees & Action Items Resulting from Meeting Encl

ML20236Y440
Person / Time
Site:	Point Beach
Issue date:	07/01/1981
From:	Colburn T Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
IEB-80-11, TAC-42896, TAC-42897, NUDOCS 8712110324
Download: ML20236Y440 (9)

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• JUL 0113e; Docket Nos. 50-266 h\C Nb b l and 50-301 77;q l

Licensee: Wisconsin Electric Power Company (WEPCO)

Facility: Point Beach Nuclear Plant Units 1 and 2

SUMMARY

OF SITE AUDIT AND MEETING HELD WITH WISCONSIN 1 ELECTRIC POWER COMPANY REGARDING THEIR RESPONSE TO IE I BULLETIN BO-11, MASONRY WALLS.

l On June 9-11, 1981 members of the NRC staff met with WEPCO and their f j

consultants (Bechtel and Computech) at the Point Beach Nuclear Plant '

to conduct an onsite review and audit of Wepco's responses to IE Bulletin 80-11, Masonry Walls. A list of attendees is attached as l Enclosure 1.

The audit commenced with an introduction by the NRC staff outlining the proposed agenda. This was followed with a site walkdown and inspection. of the more than 50 walls being evaluated. WEPCO and their representatives, Computech and Bechtel, then presented the approa'ch they took and the assumptions that they made in developfng their reevaluation criteria. Computech's analysis assumed all walls were unreinforced. They stated that this was a conservative assumption and that it was made due to difficulty in accurately determining the location and number of reinforcing rebars within the walls. Data was taken on each wall analyzed for both the grouted and ungrouted case.

WEPCO stated their interpretation of " Safety related equipment" when used in conjunction with the masonry wall analysis was " equipment required to achieve safe shutdown or mitigate the consequences of an accident". They proposed seven walls for fluctual reinforcement p

repairs.

Discussions were then held to resolve differences between the NRC staff's design criteria and the criteria used by Computech in evaluating the Point Beach masonry walls. Major differences in the criteria pertain to allowable stresses for shear and tension normal to bed joints in masonry '

walls. Computech presented the data from the testFrom conducted at the the examination of

,Berkley labratory in support of their argument.

test data and actual calculation for Point Beach masonry wall, the staff accepted some relaxation in allowable stresses.

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The applicant agreed not to use inelastic and arching action methods of analysis to qualify the walls.

The end result of these discussions was the formulation of 21 action items which would resolve the NRC's concerns regarding the analysis of masonry walls at Point Beach. A listing of these items is included as enclosure 2. These items were agreed upon by the parties present subject to management approval.

The last item covered in the audit-meeting was the detailed review of the calculations performed in Computech's analysis for each of_ the categories of walls.

A summary meeting was held to reiterate the action items and establish schedules for submittal. The Senior Resident Inspector at Point Beach-attended in addition to those listed on Enclosure 1.

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Timothy- . Colburn, Project Manager Operati.ng Reactors Branch #3 Division of Licensing Enclosure 1: List of attendees '

Enclosure 2: Action Items cc: See next'page e

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Licmae+: Wisconsin Electric Power Company i

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201:nir:ki JHelte.::s, AE03 l EGr'mes T,Cle rL Profect Manager Licens,ing Assistant

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Wisconsin Electric Power Conpany CCi Mr. Bruce Churchill, Esquire Mr. William Guldemond Shaw, Pittman, Potts and Tr.ubridge USNRC Resident Inspectors Office ,

1800 M Street, H. W. 6612 Nuclear Road l Washington, D. C. 20036 Two Rivers, Wisconsin 54241 <

l' Joseph Mann Library 1516 Sixteenth Street Two Rivers, Wisconsin 54241 Mr. Glenn A. Reed, Manager Nuclear Operations Wisconsin Electric Power Conpany Point Beach Nuclear Plant 6610 Nuclear Road

- Two Rivers, Wisconsin 54241 Mr. Gordon Blaha -

Town Chairman  !

Town of Two Creeks Route 3 Two Rivers, Wisconsin 54241 Hs. Kathleen M. Falk General Counsel Wisconsin's Environmental Decade l

302 E. Washington Avenue .

Madison, Wisconsin 53703 .

Director, Criteria and Standards Division Office of Radiation Programs (ANR-460) -

U.S. Environmental Protection Agency Washington, D. C. 00460 l l

U. S. Environmental Protection Agency Federal Activities Branch ,

Region V Office l ATTN: EIS COORDINATOR 230 S. Dearborn Street Chicago, Illinois 60604 Chairman  !

Public Service Comission of Wisconsin Hills Farms State Office Building Madison, Wisconsin 53702 l

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' Enclosure 2 ACTION ITEMS RESULTING FROM

> NRC & WE STAFF MEETING JUNE 9-11, 1981 The licensee will complete the following action items:

j. 1. The licensee, in order to qualify for the use of special l inspection allowable stress category, has proposed the following test:

l Five prism samples, each 3 blocks high by 8 inches wide of (a) stairwell, (b) turbine room Wall 68, (c)

Wall 150, (d) Wall 65, and (e) Wall 104.

This test will determine the f6 value according to the requirements of ASTM E-44'/-74.

If scatter is considered to be excessive by the NRC staff, consideration will be given to conducting two additional tests. The value of f; shall be the average of the value of the specimens tested or 125% of the minimum value deter-mined by the test, whichever is less, but in no case shall exceed 1000 psi. ,

i In addition, the licensee will also determine m values to justify the 750 psi value used in the analysis.a The licensee should provide the procedures to be used to estab-lish mo by 07/15/81 for NRC review.

The test results shall be submitted to the NRC staff by 09/15/81. If difficulties in conducting the test arise, the NRC staff shall be contacted to determine a resolution.

2. The licensee will provide documentation including calcu-lation sheets that indicate that the adoption of 5 modes (

of seismic response will generally provide 95% of the i

. total response. This information will be provided to the NRC st&If by 07/15/81.

3. With respect to the containment isolation valves for steam generator blowdown lines outside containment at El. 26',

the licensee indicates that additional remote-operated isolation valves within containment will be installed by the Fall of 1982 and Spring of 1983 for Units 1 and 2, respectively; thus eliminating the concern originating l from the potential failure of the stairwell masonry walls. .

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I l I The licensee is requested to provide a commitment that i '

installation will be completed by the above dates and a technical evaluation that the delay will be acceptable from a probalistic standpoint for NRC staff review and appreval by 07/15/81. -

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The licensee will also review the plant safety aspects l associated with failure of the steam generator blowdown l isolation valves due to masonry wall failure. If a safety concern exists, it shall be identified and evaluated and submitted with the above technical evaluation.

4. With regard to allowable tensile stre sses normal to bed i joint, the licensee shall provide the following by l 09/15/81:

a. Applicability of NCMA and other test data to the Point Beach masonry walls, with particular emphasis on the static nature of the test as compared to the dynamic /

seismic' loading being evaluated.

b. Discussion of the results obtained from dynamic tests conducted at Berkeley (Reference 1) and discuss their non-applicability with respect to the bed joint tensile stresses.

c. Discussion and justification for higher allowable tensile stresses for SSE than those allowed for OBE.

It is the NRC position that such increase should not i

exceed 33-1/3% of OBE values,

d. Technical discussion demonstrating that high safety margins in wall capacity exist even after first sig-nificant cracking has occurred due to out-of-plane shaking in light of the tests conducted at Berkeley (Reference 1). Also, provide quantitative safety margins obtained by dividing experimental ultimate wall capacities with the wall capacity based on allow-able stresses.

e. Statistical summary of the Berkeley test data as described in Item 6.a.

5. With regard to out-of-plane loading, the licensee shall demonstrate that the use of single wythe assumption for i multiple wythe wall results in conservative evaluation with respect to frequency shift and out-of-plane drift consideration by 09/15/81. .

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6. With. regard to in-plane shear evaluation, the licensee-shall provide the following by 09/15/81:

a. Statistical summary of test data presented at the meeting (Reference 2) to develop the strain values corresponding to mean, lo, 20, and 30 levels with 95%

confidence intervals for both OBE and SSE consider-ation. Also, determine the probability of exceedance corresponding to the four strain level values used in the criteria.

b. Nominal allowable shear stress corresponding to OBE and SSE strain values accounting for stiffness degradation (30%) based on above test results. In no case this value shall exceed 43 psi.

c. Discussion and technical basis that test data utilized in developing Item 6.a are pertinent for Point Beach masonry wall reevaluation application, e.g., aspect ratio, fm, mortar strength.

d. Technical discussion of the state of deformation of masonry walls (e.g., initial cracking and significant cracking as defined by limiting strain values, crack pattern and propagation). Also, discuss the safety significance of the walls at these strain levels, e.g., safety margin with respect to the loss.of wall function.

e. Evaluate the ef fect and assess the impact on out-of-plane stiffness due to in-plane cracking at these four strain levels.

7. The licensee shall provide the justification for using plate solution for Wall '3/1' by 09/15/81.

8. Walls subject to flexure in the vertical direction shall be provided with a positive anchor or equivalent at top and j bottom or justification for not doing so will be provided i for review by 08/15/81. Also include the maximum tensile l stresses normal to the bed joint due to out-of-plane loads  ;

j for each wall.

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9. provide evidence by 09/15/81 that the BSSC (Building i Seismic Safety Council) has voted approval of Ballot Item '

5A/46 of National Bureau of Standards Report No. NBSlR {

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10. Provide a. copy of each of the documents presented during the meeting and used in support of justification by-07/15/81.

11. The licensee shall' provide.the criteria and' procedures to account for the out-of-plane interstory drift effects in seismic-analysis by 09/15/81.

12.- The licensee is required to comply with the requirements of plant operability provisions of the plant Technical Specifications as specifically identified in.IE Bulletin No. 80-11. The licensee will inform the NRC of its planned action with respect to this item by 07/1h/81.

11 3 . The seismic responses due to horizontal and vertical earth-quake motions were combined absolutely for the purpose of masonry wall evaluation.

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14. The licensee will provide a set of floor response spectra for both 2% and 4% dampling used in the masonry wall

' evaluation at pertinent elevations for both auxiliary building and control building by 07/15/81. ,

15. The-licensee will provide an assessment of the possible impact on wall capacity / behavior for neglecting the presence of an undefined amount of reinforcement in the masonry and assuming the walls as unreinforced in the .

analysis by 08/15/81. ,

16. The licensee will provide comparative analyses on three types of Point Beach masonry walls (four sides simply supported, three sides simply supported and two sides--

vertical and horizontal--simply supported) using both the plate assumption and one-way beam action in two orthogonal ,

directions to assess the safety margins incorporated in i the plate analysis by 09/15/81.

17. The licensee wi11' provide a list of walls to be fixed or further strengthened beyond the present wall status and descriptions of such fixes (with sketches) and the expected completion dates of the fixes by 07/15/81.

18. With regard to Wall 19, the licensee shall evaluate out-of-plane drift effects resulting from the addition of knee braces at the top, provide the information for NRC review by 08/15/81.

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19. With regard to -Wall .5-5, the licensee shall clarify the applicable piping loads, manner of attachment, and their use in analysis by 08/15/81.

20. The licensee shall revise the criteria submitted on 11/14/80 to reflect the agreements reached in this meeting including deletions of positions on reinforced masonry and alternate acceptance criteria by. 08/15/81.

21. Above positions are developed for the Point Beach specific based on detailed evaluation of technical information and calculations presented at the audit meeting.

'Beferences:

1. EERC Masonry Shaking Table Tests, Report Nos. 79/23 & 79/24.

2. EERC Masonry Pier Tests, Report Nos. 76-8, 78/28 & 79/12, I

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