ML17254A626
| ML17254A626 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 11/05/1985 |
| From: | Clifford J Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8511110402 | |
| Download: ML17254A626 (27) | |
Text
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Docket No.
50-244 0
UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 ZOV O5 1SS5 LICENSEE:
Rochester Gas and Electric Corporation FACILITY:
R.
E. Ginna Nuclear Power Plant
SUBJECT:
SUMMARY
OF OCTOBER 17, 1985 MEETING ON CONTAINMENT VESSEL TENDON SURVEILLANCE PROGRAM On October 17, 1985, the staff, along with its consultants, Franklin Research Center (FRC), met with Rochester Gas and Electric Corporation (RGSE) and their consultants, Gilbert Commonwealth, at NRC staff headouarters in Bethesda, Maryland (see ).
RGAE requested this meeting with the staff to discuss FRC recommendations made in a Safety Evaluation Report (SER) on August 19, 1985 regarding R.
E. Ginna Containment Tendon Evaluation.
A slide presentation was made by the licensee (see Enclosure
- 1) which included a background discussion on Ginna's containment tendon surveillance program and the various past submittals to the NRC.
After the introduction, the licensee provided a technical presentation that addressed the four recommendatons presented in the SER.
The four recomendations made by the staff were:
- 1) the licensee should maintain lift-offforce surveillance of the wall tendons to account for the insufficient data upon which the refined relaxation prediction methods are based;
- 2) the licensee should continue the experimental investigation of tendon wire relaxation using a larger and broader sample of test specimens;
- 3) the licensee should introduce more accurate measurement and recording methods for tendon elongation and stressing jack displacements to enable comparative estimates of tendon system behavior in an effort to discern rock anchor slippage; and
- 4) the licensee should provide rock creep analysis based upon more comprehensive methods including shear mode effects and extrapolation of rock test data.
In response to Item I above, RGSE provided the results of its surveillance program performed at an increased frequency during the past 5 years.
The licensee indicated their intention to perform containment tendon surveillance at five year intervals, as requi red by their TS.
With regard to Items 2 and 3 the licensee stated that it feels that no additional laboratory testing appears necessary, and that the present tendon evaluation program utilizes the most accurate and up-to-date methods available.
In response to Item 4, RGSE re-examined previous rock cr eep analysis and found that an error indeed had been
- made, but was of minor significance.
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~ I NOV 0 5 1985 After the licensee's discussion of the staff's recommendations, the staff summarized the background regarding the recommendations in the SER.
The staff felt that the size of the sample in Item 2 of the staff's recommendations was small and recommended that the licensee perform more testing of the containment tendon test samples.
RGSE stressed the fact that it had already expanded the test program from 3 samples of one wire heat to include 7 samples encompassing 3 (of 6) wire heats.
The licensee feels that this test program, in conjunction with the surveillance test data through 1985, adequately validates the stress prediction model, and no further testing of wire heats is necessary.
The staff also stated in Item 3 that the tendon is elongated during surveillance, although it was acknowledged by only a small amount.
The licensee agreed with the basic point of minute amounts of tendon elongation during surveillance testing, but felt it was insignificant enough to be discounted in evaluating tendon stress levels.
The licensee felt that tendon elongation is applicable only during retensioning.
With regard to Item 4, the staff felt that the licensee should address the rock creep
- analysis, and include shear mode effects and extrapolation of rock test data.
The licensee agreed to:
- 1) discuss the sample size mentioned in Item 2,
- 2) discuss elongation during both surveillance and retensioning,
- 3) discuss rock creep analysis to include shear mode effects,
- 4) reference a
previous submittal regarding an accident with Tendon 75, and 5) formally provide the results of the 1985 surveillance on containment tendons.
In closing, the staff reiterated the fact that no safety concern exists with the Ginna containment.
(This conclusion was documented in our Safety Evaluation dated August 19, 1985).
The staff concurs that the 5 year surveillance interval is appropriate.
The staff made note of RGSE's exemplary containment tendon surveillance program.
The staff also stressed to RGAE that the comments mentioned above were recommendations to the licensee, not requirements.
The licensee will formally submit a discussion of the recommendations made in the SER.
Because all safety concerns have been satisfactorily addressed by the licensee, and because the information being provided is only to document the discussions at this meeting, the RGSE containment tendon surveillance issue is considered resolved.
Gfz~~ ~~ py James W. Clifford, Project tlanager Operating Reactors Branch No.
5 Division of Licensing
Enclosures:
As stated cc:
See next page
.DISTRIBUTION NRC PDR LPDR ORBS'5 Reading JZwolinski JClifford JKelly CJamerson OELD EJordan BGrimes ACRS (10)
NRC Participants DL:ORB45
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JKel ly:tm IP/4/85 DL:
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/85 DL:ORB//5 J2wolinski 1)/f /85
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After the licensee's discussion of the staff's recommendations, the staff summarized the background reoarding the recommendations in the SER.
The staff felt that the size of the sample in Item 2 of the staff's recommendations was small and recommended that the licensee perform more testing of the containment tendon test samples.
RG&E stressed the fact that it had already expanded the test program from 3 samples of one wire heat to include 7 samples encompassing 3 (of 6) wire heats.
The licensee feels that this test program, in conjunction with the surveillance test data through 1985, adequately validates the stress prediction model, and no further testing of wire heats is necessary.
The staff also stated in Item 3 that the tendon is elongated during surveillance, although it was acknowledged by only a small amount.
The licensee agreed with the basic point of minute amounts of tendon elongation during surveillance testing, but felt it was insignificant enouoh to be discounted in evaluating tendon stress levels.
The licensee felt that tendon elongation is applicable only during retensioning.
With regard to Item 4, the staff felt that the licensee should address the rock creep
- analvsis, and include shear mode effects and extrapolation of rock test data.
The licensee agreed to:
- 1) discuss the sample size mentioned in Item 2,
- 2) discuss elongation durinq hoth urveillance and retensioning,
- 3) discuss rock creep analysis to include shear mode effects,
- 4) reference a
previous submittal regarding an accident with Tendon 75, and
- 5) formally provide the results of the 1985 surveillance on containment tendons.
In closing, the staff reiterated the fact that no safety concern exists with the Ginna containment.
(This conclusion was documented in our Safety Evaluation dated August 19, 1985).
The staff concurs that the 5 year surveillance interval is appropriate.
The staff made note of RG&E's exemplary containment tendon surveillance program.
The staff also stressed to RG&E that the comments mentioned above were recommendations to the licensee, not requirements.
The licensee will formally submit a discussion of the recommendations made in the SER.
Because all safety concerns have been satisfactorily addressed by the licensee, and because the information being provided is only to document the discussions at this meeting, the RG&E containment tendon surveillance issue is considered resolved.
Enclosures:
As stated
, i8.gg~-d Ja es W. Clifford, Project Yanager Op rating Reactors Branch No.
5 Division of Licensing cc:
See next page
CC:
Harry H. Voigt, Esquire
- LeBoeuf, Lamb, Leiby and MacRae 1333 New Hampshire
- Avenue, N.W.
Suite 1100 Washington, D.C.
20036 Ezra Bialik Assistant Attorney General Environmental Protection Bureau New York State Department of Law 2 World Trade Center New York, New York 10047 Resident Inspector R.E.
Ginna Plant c/o U.S.
NRC 1503 Lake Road
- Ontario, New York 14519 Stanley B. Klimberg, Esquire General Counsel New York State Energy Office Agency Building 2
Empire State Plaza
- Albany, New York 12223 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 631. Park Avenue King of Prussia, Pennsylvania 19406 Supervisor of the Town of Ontario 1850 Ridge Road
- Ontario, New York 14519 Jay Dunkleberger Division of Policy Analysis 8 Planning New York State Energy Office Agency Building 2 Empire State Plaza
- Albany, New York 12223 Roger W. Kober Vice President Electric and Steam Production Rochester Gas and Electric Corporation 89 East Avenue Rochester, New York 14649
ENCLOSURE 1
OCTOBER 17, 1985 MEETING WITH ROCHESTER GAS 8: ELECTRIC CONTAINMENT TENDONS NAKE Jim Clifford Janet Kelly Clyde Forber Douglas R. Campbell Jim Fulton Paul Vi1kens John A. Zwolinski John T.
Chen Chen P.
Tan R.
Clyde Herrick Terry h~eiss AFFILIATION NRC/DL/ORB-5 YRC/DL/ORB-5 RGSE Gilbert/Commonwealth Gilbert/Commonwealth RGSE NRC/DL/ORB-5 NRC/SGEB NRC/SGEB Franklin Research Center RGSE
Ginna Nuclear Power Station Containment Tendon Investigation Meeting Agenda October 17>
1985 I.
Introduction II.
Technical Presentation A.
Continued Tendon Surveillance Program B.
Predicted vs.
Measured Tendon Forces 1.
Results from 1981<
'83 and
'85 Surveillances C.
Tendon Elongation and Stressing Ram Displacement D.
Rock Creep Evaluation III.
Discussion IV.
Summary
0'ince there are insufficient data upon which the refined relaxation prediction methods are based, the licensee should maintain lift-offforce surveillance of the wall tendons to offset the deficiency.
2.
Continue the ex erimental investi ation of tendon wire relaxation usin a lar er and broader sam le of test s ecimens.
This would provide a better foundation of knowledge to guide future lift-off surveillance programs and aid in the explanation of any further unexpected behavior.
3.
Introduce more accurate measurement and recordin methods for tendon elon ation and stressin
'ack dis lacements to enable com arative estimates of tendon s stem behavior in an effort to discern rock anchor sli a
e.
Re-examine previous analysis for rock creep and provide
. analysis based upon more comprehensive methods including shear mode effects and extrapolation of rock test data.
R.E. GINNACONTAINMENT r
TENDON EVALUATION REVIEW OF NRC SAFETY EVALUATIONREPORT (ENCL. 1 TO AUGUST 19, 1985 NRC LETTER)
PRESENTED AT OCTOB ER 17, 1985 MEETING
RETENSIONED WIRE TESTS AND "FACTOR" METHOD r
~
Final Report: GAI Rpt. No. 2499 (Dec. 1983}
The retensioned wire tests (final)
~
Prelim. Report: GAI Rpt. No. 2347 (Feb. 1982)
The "investigation-of-cause" report Conceptual 5 preliminary for retensioned wire tests
~
11 yr. extrapolations can be made (Figs. 3-E thru 3-6}
'" ~
7 retensioned specimens covered all three test heats
TABLE 1 STRESS RELAXATION TEST CONDITIONS OF RETENSIONED WIRES Tendon I.D.
Specimen No.
Time at Retensioned Heat Stress Temperature Retensioning Duration
'No.
(XGUTS)
( F)
(Hours)
(Hours) 51-B 51-C 19477 19477 70 70 104 68 r
6000 1000 18214 11137 76-C 76-B1 76-B2 76-B 10 30091 30091 30091 30091 70 70 70 70 104 104 104 68 10190 100 1000 11600 14229 8635 19229 3575 150-C2 12 10355 70 68 5500 9720 Qbert /Commonwealth 21
IS Id fji jk 1S l3 12 11 5
10 I
9 8
IIn
,li:
'ri i'I.
I s+"
fiji il II.I I.
'.0 1000 TIME IHOURS) 10,000 FIGURE S BASE AHO RETEHSIOHEO RELAXATIOHFOR ACTUALTEHOOHS
TABLE l. BIHHA SURVEILLANCE TEHDONS ITEN TEHDOH HO.
HEAT NO.
S U R V E I L L A H C E P
E R I 0 O
NO 1981 1983 1985 NEASURED FORCE (KIPS)
PREDICTED FORCE
[KIPS)
PERCENT DIFFERENCE 2
4 5
6 7
8 9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 13 13 17 17 18 18 21 21 33 35 35 36 36 40 40 51 51 53 53 60 60 62 62 63 63 71 73 74 74 75 75 76 76 76 77 84 84 93 93 103 111 111 116 116 120 120 125 125 126 128 128 19477 19477 NIXED NIXED 30091 30091 21504 21504 103S5 10355 10355 10355 NIXED NIXED 30091 30091 19477 19477 19477 19477 21504 21504 21504 21504 21504 21504 NIXED 30091 1035S 10355 30091 30091 NIXED NIXED NIXED 21504 21504 21504 39377 39377 21504 UHSPEC UNSPEC UHSPEC UHSPEC UNSPEC UHSPEC 30091 30091 30091 30091 30091 X
X X
730 730 727 717 727 705 723 725 673 679 662 653 664 657 731 724 709 710 731 734 711 702 715 716 722 713 705 654 710 731 723 518 703 713 700 723 714 710 706 713 703 646 643 690 693 680 679 702 705 692 711 709 711 721 734 715 721 714 704 723 665 670 650 648 661 664 7!1 704 712 723 711 722 707 700 720 730 730 711 707 624 690 708 709 460 696 714 704 702 713 695 711 721 699 647 642 658 656 661 659 716 726 659 696 703 2.7X 1.2X
-1.0X 0.3X 0,8X
-1 ~ 3X 2.7X 0.3X 1.2X 1.3X 1.8X 0.8X 0.5X
-1 ~ 1X 2.8X 2.8X
-0.4X
-1 ~ 8X 2.8X 1.7X 0.6X 0.3X
-0.7X
-1.9X
-1.1X 0.3X
-0.3X 4.8X 2'X 3.2X 2.0X
~2.6X KZX
-0.1X "0.6X 3.0X 0.1X 2.2X
-O.TX
-1.1X 0.6X
-0,2X 0.2X 4~4.9.
t5.6X
'.9X 3.0X
-2.0X
-2'X
~5.0 2 ~ 2X 0.9X
TABLE 1.
GIHHA SURVEILLAHCE TEHDDHS 53 54 55 56 57 133 39377 X
155 19477 X
155 19477 160 19477 160 19477 734 738 745 721 705 718 713 703 709702'.2X 3'X 0.4X TOTAL 57 18 18 21 702 AVE 693 AVE I ~ 38X AVE
TABLE2.
GINNATENDONS - BYWIRE HEAT
¹30091(76)
¹10355(150)
(Test Heat)
¹21 504
¹39377
¹22332 UnsPecified Heat 3*
4 26 16 127 7
2 18 129 30 130*
31*
32*
39 40 41*
45 46 47*
48 49*
55 56 57 58 1
73 6
106*
107*
108 109 10 12 13 14*
23 25 26 27 28 51 52 54 137 138 141 142 143 145 149 152 153 154 5
156 157 158 159 60 15 7
33 34 35 36 37 38 71*
72 74 76 107*
123 124 139 140 150 151 14*
19 20 21 22 41*
42 43 44 50 59 60 61 62 64 65 67 68 69 70 77 78 79 80 81 82 83 84 85 86*
87*
90*
101 102 03 104 134*
146 147 148 29 31*
86+.
87*
88 89 90*
91 92 93 94 95 96 97 98 99 100 105 106*
130*
131 132 33 134*
135 136 47*
49*
110 11 112 113 114 115 1
117 118 119 2
121 122
- = Tendons with mixed wire heats Bold Face ='1, '83 or '85 Surv. Tendons (circled)
TABLE3.
WIRE HEATAND 1981, 1983 and 1985 SURVEILLANCETENDONS **
¹ 3 009 1 (Test)
¹19477(Test)
¹10355(Test)
¹21 504
¹39377 Tendon b,
Tendon b,
Tendon 6
Tendon 6
Tendon b,
126 73 40 40 128 75 128 18 18 125 125 50 155 4.8, 155 28 53 28 13 22 53 20 160 09 13 08 160 1.3 51
-20 51 2.9 6.0 3.5 2.8 2.7 1.7 1.7 1.2 0.4 0.4 1.8 74 35 33 33 35 74 3.2 1.8 1.3 1.2 0.8 2.9 77 21 84 103 60 60 63 21 84 62 63 62 3.0 2.7 2.2 0.6 0.6 0.3 0.3 0.3 0.1
- 0.7 1.9 133 93 93 2.2 0.7 Ave.
1.37 Ave.
1.78 Ave.
0.9 Ave.
0.5 Ave.
0.1 NOTES
6 = % Difference in Tendon Force:
X 100%
Predicted
- Predicted tendon forces are based on stress relaxation values from the 16% Base Relaxation curve multiplied by applicable Retensioning Ratios
850 FIGURE 18 COMPARISON OF PREDICTED.
AND MEASURED TEHDOH FORCES INCLUDINGRETFHSIOHIHG FOR TENDON NO. 76 v
1 I
01 PREVIOUS SURVEILLANCE LIFT OFF 800 R 750 IJI O
K O
700 I
ORIGINAL LOCK OFF VALUE RT LOCK OFF VALUE SURVEILLANCE LIFT OFF I-X A~
WX O Cg LU @
ssl (2) 16% RELAX.
~ X W
I-X O
ClX LUI-X X
O O
WOX LUIL'J OX CC 1
1 ILv i"
O-
'X LU ILv i UJOX s
W O
X O
I-IL X
W
~.
W s
I-CC IL'
'I
~
W RT LIFT OFF VALUE IL UJ's W I oN I-IL IL UJ Itl I-IU IY W
Cl (1) E.S.R.
WITH RT I ITTTTHIIIILIIB 95% X (2)
~
95% X (I)
E.S.R.
WITHOUT RT 2v0 2.5 4.5 9.6 12.0 13.d 15.d 17.d 22.6 27.6 32.6 37.6 42.6 12.6
.850 4 ~
FIGURE 21 COMPARISON OF PREDICTED AND MEASURED TEHDOH FORCES INCLUDINGRETENSIOHIHG FOR TENDON NO. 93 Oi PREVIOUS SURVEILLANCE LIFT OFF 800 m
750 IJIO OC CI X
O 700 CI I
ORIGINAL LOCK OFF VALUE RT LOCK OFF VALUE SURVEILLANCELIFT OFF I-TI-A Q WX U CT:
W Le Vl ~
(2) 16% RELAX.
WITH RT 650 600 QI'X
'W IL I
X OQX WI-ZI-
'X0 WUX W
IL' U
'X CL WUX CL '
UX
~ W CCD P
IL'I O
I-X IL WI-wI I
CC IL' RT LIFT OFF VALUE CI I-CL' W
r WLI CI I-IL'L W
~A I ec I
CC W
CI (1) E.S.R.
WITH RT 95% X (2) 11111111111 JJ 11 95% X (1)
IllIITIIIIIIIII E.S.R.
WITHOUT RT 2.0 2.5 4.5 9.6 12.0 13.6 15.6 17.6 22,6 27.6 32.6 37.6 42,6 12,6
850
~
~
4
~
FIGURE 32 COMPARISON OF PREDICTED AHD MEASURED TENDON FORCES INCLUDING R ETENSIOHIHG FOR TENDON HO.
33 QO PREVIOUS SURVEILLANCE LIFT OFF ORIGINAL LOCK OFF VALU RT LOCK OFF VALUE 750 III LI CC CI O
700 O
I TOF LIF VALU VEIL P R EDICT ED (HEAT HO. 10355)
CE LIFTOFF'-
I RQ W W U Cg
~
W ~o an 650 (1) E.S.R WITH RT TTTTTH TTTTITlTl (2) 16% RELA WITH RT 600'n z..
O' X
I-X a
! Z0 i
WUX W
CC W
I WUX W
ILD 1
Cg W
WUZ WUX W
IL' an IL W
0" X
X O
I-CC X
WI-w wI t
.I
. CY
~ K
, W CI I-lL I.
W S
I-IL OC W I' I
CL' cc I
CC CC W
CI 95% X (I) 95% X (2) 1.4 2.0 2.5 4.5 9.6 12.0 13.6 15.d 17.d 22.6 27.6 32.6 37.6 42.6 12,6
STRESS RELAXATIONTESTS - CODE REQUIREMENTS hs i~~
~ The Code governing concrete containments, ASTM Section III,Division 2, Subsection CC, contains the rules for stress relaxation testing. of prestressing elements (wires}. These rules appear in paragraph CC-2424 of the Code.
The rules state:
"A minimum of three relaxation tests of 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> duration shall be performed..." and "... the tests shall be performed on material previously manufactured to the same ASTM or other applicable specifications, and produced in the same plant utilizing the same procedures that will be employed to produce the prestressing elements for the production tendons."
The Code rules do not require stress relaxation tests on each different heat of wire to be used in the tendons.
From this standpoint, the stress relaxation tests performed on the Ginna tendon wires have significantly exceeded the Code requirements.
STRESS RELAXATIONTESTS - CONCLUSIONS
~ The stress relaxation tests, including both the number of different heats tested and the number of specimens involved, appear to be sufficiently adequate.
These results were evaluated in detail and were used to establish the 16%
Base Relaxation curve and the retensioning
- ratios, which have in turn yielded predicted tendon forces that agree very well with the forces measured at the tendon surveil lances performed thus far.
The data and methodology continue to provide an effective means of monitoring the tendon
- forces, and additional tests are not needed.
TENDON ELONGATIONS
~
No tendon elongations exist during lift-offtests Transfer of bearing force from bearing plate to stressing ram 1/4 inch (max.) ram piston move'ment during load transfer (700 kips), measured to 1/16 inch accuracy
~
Past opportunities to measure elongations 1.
Rock anchor stressing in 1969 Ram piston movement recorded at 7 points, allowing load-elongation curves to be plotted which were linear(GAl Rpt.- Response to NRC-3une, 1983)
No. 46 taken through complete load/unload cycle 2.
Wall tendon stressing in 1969 predictable elongations {GAIRpt. No. 2349) 3.
June 1980 tendon retensioning of 137 {out of 160) tendons 2 inches Predictable
TENDON ELONGAT!ONS (CONT'D)
~
Conclusions:
The FRC comments on increasing the accuracy of the tendon elongation measurement are not applicable for the lift-offtests. However, past tendon elongation measurements, as recent as the June 1980 retensioning, tend to demonstrate the integrity of rock anchors.
ROCK CREEP
~
Rock creep strain re-evaluated Tendon loss:
8 kips -122 kips given in GEI Rpt.
Creep test on Ginna Site rock shows 8 kips, not 122 kips, to be more likely Stress relaxation tests results account for much more than 8 kips
~
Rock creep calcu lational model Column idealization, {widthof ring footing) which gave 472 psi compressive stress uniform over 34 ft.
height of column Actually, bearing load under footing spreads out in rock Therefore, actual creep strain which would give rise to anchor shortening is less than that corresponding to 472 psi Model expected to be conservative enough to overcome any additional loss that might be calculated by including the shear deformation of the rock in a less conservative, and more realistic, calculational model for the rock
C V
Q.
~J
~ I I
~
Flgwre ~ej I
t
~ IiI 0
!CCO 2C00 3%0 CCC0 joo Stress kg/cm'ehtionship beaveen creep exponent and stress.
Reprociuced rom:
Z. W. Fa~er, Zncineerinc Proper"ies of Rock 1968 FIGURE 35.
CREEP EXPONENT VERSUS STRESS
ROCK CREEP - CONCLUSIONS
~ Correcting the error pointed out by GEI in the previous rock creep calcu lation appearing in GAI Report No. 2347 increases the calculated value of tendon loss from that reported previously. But the revised value is based on a very conservative calculational model for the rock; and still, its magnitude is not large enough to alter the previous conclusion that stress relaxation.
is the primary reason for the larger-than-predicted tendon losses which occurred prior to the June 1980 retensioning.
e This point is further emphasized by the fact that subsequent to the June 1980 retensioning, the tendon forces measured on three separate occasions at the 1981, 1983, and 1985 surveillances are predictable even ignoring rock creep.
This is to be expected since any rock creep that may still be occurring would be doing so at a creep rate that is insignificantly small considering that the rock has been stressed by the rock anchors for 16 years.