IR 05000353/1989018

Insp Rept 50-353/89-18 on 890429-0506.No Violations Noted. Major Areas Inspected:Structural Integrity Test Procedures & Implementation & Qa/Qc Involvement W/Integrity Test Procedures

ML20244B732
Person / Time
Site:	Limerick
Issue date:	05/17/1989
From:	Carrsco J, Chaudhary S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20244B729	List: IR 05000353/1989018 ML20244B727
References
50-353-89-18, NUDOCS 8906130248
Download: ML20244B732 (9)

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U.S. NUCLEAR REGULATORY COMMISSION REGION I-Report N /89-18 Docket N _0-353 License N CPPR-107 Licensee: Philadelphia Electric Company 2301 Market Street-Philadelphia, PA 19101 Facility Name: Limerick Nuclear Generatino Station, Unit 2 Inspection At: Limerick, Pennsylvania Inspection Conducted: Acril 29 M -6, 1989 Inspectors: A WdJtC9 S-/7"!9 Josepk fp Carrasco, 1eactor Engineer' Date-Approved by: A-ctut/ M/ /7 81 Suresh Chaudharf, Chief, MPS Date Engineering Branch, DRS, RI Insoection Summary: Routine unannounced insoection on ADril 29 -

May 6, 1989 (Inspection ReDort No. 50-353/89-18)

Areas Insoected: Structural Integrity Test;(SIT) procedures and implementation; involvement of QA/QC with the SI Results: Based on the review of the SIT results the inspector determined that the' preliminary results appear' acceptable.-- l l

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8906130248 890605 "

PDR ADOCK 05000353 >

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I DETAILS ]

l 1.0 Persons Contacted

] Philadelphia Electric Company l l

• H. W. Vollmer, Section Manager Civil / Mechanical Plant ~ j

• D. M. O'Rourke, Structural Engineering Branch Head

• R. Reifsnyder,-Nuclear QA Engineer I Bechtel Incorporated j

.) Patel, SIT Test Director l J. Galanti, SIT Test Director Alternate ) Lieb, Quality Control j Simmons, Test Supervisor l Gonzales, Test Enginee I

• V. K. Aggarwal, Civil Group Supervisor l

• S. Mitkal, QA Engineer j

• S. H. Loo, Project Engineer Civil Kemper Insurance Company I

G. Voishnis, Authorized Nuclear Inspector )

I U.S. Nuclear Reculatory Commission J. M. Trapp, Reactor Engineer R. Fuhrmeister, Resident Inspector T. Kenney, Senior Resident Inspector

• Denotes those present during the exit meeting held on May 8, 198 .0 Introduction and Overview  ; Backaround Current licensing regulations require that containment structures protecting water cooled nuclear power reactors be pressure tested before a nuclear power plant may be placed into service. The purpose of the test is dual in nature. First, the structural response of the containment to the test pressure is intended to provide the design engineer the information to evaluate and validate design assumptions; second, the test will reveal serious construction deficiencies, if they exis . - _ _ - _ _ _ _ - _ -

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The structural integrity test, therefore, is to demonstrate that the primary containment responds to internal pressure as analyzed and documented in final safety analysis repor .0 Procedure and Organization The inspector reviewed the Bechtel procedure for the structural integrity test (titled, " Specification for Primary Containment Structural Integrity Test for the Limerick Generating Station Units 1&2 Philadelphia Electric Company" No. 8031-C-112) against the USNRC Regulatory Guide 1.18 Revision 1, Structural Acceptance Test for Concrete Primary Reactor Containments; ASME B & PV Code,Section III, Division 2, Article CC-6000, July 1980 Edition; and the Limerick Generating Station Unit 2 FSAR Section 3.8.1.7.1.1, structural acceptance tes Based on this review, the inspector determined that the Bechtel procedure was adequate for the implementation of the Structural Integrity Test (SIT).

Bechtel had established two test teams for covering the test on a twenty four hour basi Each team consisted of pretest, control room monitoring, crack mappers and calibration crews. The inspector determined that each group had sufficient personnel to perform the task effectivel .0 Acceptance Criteria The licensee had established the following acceptance criteria for the structural integrity of the containmen .1 Displacement Measurements The maximum allowable displacements for the containment structure were:

(a) The average containment wall radial displacement at any elevation to be less than 0.537 inche (b) The measured containment wall vertical displacement to be loss than 0.574 inche .2 Visual and Con.; rete Crack Inspection (a) Total width of any one crack to be less than 0.060 inche (b) No visibly detectable signs of damage to either the concrete structure or the steel lin p -- .

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l I The Deflection Recovery j l

(a) If the measured deflections at joints of maximum predicted deflection did not exceed the maximum allowable value shown in (1) above: the ;

deflection recovery at the points of maximum expected deflection within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after complete depressurization must be 70% or more. The points of maximum predicted deflection were contained in j d

supplement I of specification 8031-C-11 .(b) If the measured maximum deflection at points of maximrm predicted deflection exceeded 130% of l predicted values, the deflection ~ recovery at points of maximum expected deflection within 24 ;

l hours after complete depressurization must be 80% {

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or mor j Implementation of the Structural Intecrity Test The inspector observed that all the precautionary measures were implemented in accordance with Supplement II to the ;

specification 8031-C-112 Section ;

l According.to test plan, the primary containment was i

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pneumatically pressurized to 115% of the design pressure 2 (which is 1.15 times 55 psig or 63.25 psig) to determine the structural response of the containmen The second test was to determine the be'navior of the diaphragm (slab that divides the wet well and the dry well)

by pneumatically pressurizing the dry well.to 63.25 psig and the suppression pool to 28.50 psig to obtain a differential .

pressure ( A P) of at least 30 times 1.15 or 34.5 psi t

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The displacements were measured by using 66 displacement transducers and associated hardware located on preselected location Transducers were utilized to measure shell displacements radially and vertically, and displacements at hatches (major containment penetrations) . The locations where measurements were made are listed in Attachment I,

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.5 j The actual pressurization.of the containment began on April 29 at 1505 withla gradual build up of-pressure (3 psig/hr. nominal) as specified in specification 8031-C- l The peak pressure of 63.25 psig was reached!on

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11 April 30 atL1404 followed by 1 hr. hold for crack mapping ,

and gathering of data from all the1 transducer Certain difficulties were encountered for the second part of the SIT (the establishment of a A P for the diaphragm) due to inadequate' sealing of the down-comer cap Leakage

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through the downcomers between the drywell and wetwell were detected by air bubbles in the suppression pool. 'Several ,

leaks from the SRV lines into the suppression pool were also i detecte After all the repairs were performed to ensure a good. seal f of the diaphragm openings to the suppression pool ( down-comers and SRV lines) , the' followi*tg sequence of events -

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1) Pressurized dry well.to approximately 34 psig to {

determine if the-pressure could be maintaine ) Pressurized suppression pool to 28.5 psi ) Increased dry well pressure-to 63.25 psi ) Completed SIT procedural steps that remained incomplet ) Completed the high pressure by-pass tes #

6) Depressurized containmen ) Completed and closed out SIT test procedur The pressurization of the dry well-(step 3 above) was done !

at the rate of 8 psi /hr. reaching desired peak pressure.at 1728 on May 4. Step 6 above was accomplished at 2114 on i May '

6.0 Results The NRC inspector reviewed data summaries for >.he different phases of the test as follows:

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A summary of data taken at the start of the peak 1 pressure hold. The-data were taken at 1404 on April 30 l at 63.35 psig and 72.10 I

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A summary of data taken at the end of the peak pressure hol The data were taken at 1504 on April 30 at 63.30 psig and 74.0 .i '

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l L By review of test results, the inspector-determined that:in l 'the suppression-pool, the. maximum displacement of 0.171 inches occurred at transducer H7 located at elevation 2198-

'3" azimuth 56 degree In radial direction, this was within L the expected displacement predicted by the analysis.and'

constituted only 32% of the allowable maximum displ6 cemen Recovery displacement data taken at 0800 on May 1, at 0.00 psig and 71'50 F. The inspector determined the-

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recovery at all transducer-locations was greater.than 70%, with exceptionLof two locations, H25-located at elevation 315', azimuth 0 degrees-outside the dry well; and H27.at elevation 315', azimuth 120 degrees outside the dry well where their. recovery was 4% and 66%, .

respectivel ;)

The inspector-found these two recovery values acceptable,.

since the acceptance criteria for1% of~ recovery states,70%

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recovery applies at joints of maximum predicted value Joints H25 and H27 are not joints of predicted values fori having 70% recover Bypass Test data taken at the start.of the peak:

pressure hold at 1728 on May 4 at 62.80 psig and 70.50 Bypass Test data taken at.the end of the peak pressure l hold at 1828 on May 4 at 62.80 psig and 69.70 F.

l By review of both test results, the inspector determined i that in dry well, the maximum displacement of 0.093 inches !

occurred at transducer E20 located at elevation 258'+(12'.

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l 5") and azimuth 315 degrees inside'the dry well over .!

an equipment hatch. However, this represents only 17% of !

allowable displacement at this locatio '!

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Bypass Tcst recovery displacement data taken at 0804 on May 5 at 0.05 psig and 63.10 F. All transducer  ;

locations registered over 70% recovery.- >

7.0 Conclusion ~!

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Based on the observation of the SIT-and the review of data, the inspector determined that the SIT-was a successful tes l However, a more detailed review and analysis of the data j will'be performed by the NRC after the licensee submits his i final report to the NR !

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7- Manacement Meetinas

' Licensee management was informed.of the' scope and purpose;of'

the' inspection atLthe.beginning and_during:the inspectio The findings offthe inspection were discussed with licensee representatives during the-course of the. inspection and-presented.to the: licensee managemention May 8, 1989:atLthe exit meeting-(see' paragraph 1-for attendees).

At'no time during the inspection was written' material-provided to the-licensee.by.the inspector. The licensee didL

'not. indicate that proprietary information.wasfinvolved:

within;thel scope of-this inspectio . _ - _ _ _ _ -

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ATTACHMENT I Transducer Identification Elevation Azimuth H1 196' 30 degrees H2 196' 83 degrees H3 196' 135 degrees H4 196' 240 degrees H5 196' 274 degrees H6 196' 330 degree H7 219'-3" 56 degree H8 219'-3" 110 degrees H9 219'-3" 176 degrees'

H10 219'-3d '230 degrees H11 219'-3" 290 degrees H12 219'-3" 350 degrees H13 238' O degree H14 235'-3 1/2" 61 degrees H15 238' 126 degrees-30'

H16 238' 182 degrees H17 238' 240 degrees H18 238' 300 degrees H19 282' 30 degrees H2O 282' 90 degrees H21 282' 150 degrees H22 282' 208 degrees H23 2828 270 degrees H24 282' 330 degrees H25 315' O degree H26 315' 60 degrees H27 315' 120 degrees H28 315' 180 degrees H29 315' 240 degrees H30 315' 300 degrees D1 Vertical 45 degrees D2 Vertical 105 degrees D3 Vertical 165 degrees D4 Vertical 225 degrees D5 Vertical 285 degrees D6 Vertical 345 degrees V1 Vertical 60 degrees V2 Vertical 120 degrees V3 Vertical 180 degrees V4 Vertical 240 degrees V5 Vertical 300 degrees V6 Vertical 0 degree'  ;

El 258' Per Drawing E2 258' C-898 Bechtel E3 258'

E4 258' 1 E5 258'

E6 258'

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, 2 E7 258'+(18' 4")- 135 degrees E8- 258'+(10' 3") ,135. degrees

.E9 2 5 8 '_ + ( 7_' ) 135 degrees E10 _258'-(6'-11") 135 degrees E11 2 5 8 '_ -- ( 11 ' 4") 135 degrees E12 -258 '-(18 ' )- 135 degrees-E13 258' Per Drawing-

.E14 '258'~ C-898-Bechtel E.15 ' -258'

E16 .258'

E17 -258'

-E18 258' ~

E19 .258'+(18':4") 315'_ degrees

E20 258'+(12' 5") 315 degrees-l" E2 '+(7' 1") 315 degrees-E22 258'-(7' 7") 315-degrees E23 258'-(12'~3") 315 degrees

'E24 258'-(17' 4") 315 degrees-1

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