ML20087J043
| ML20087J043 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 03/16/1984 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 28042, 80-09-#13, 80-9-#13, NUDOCS 8403220067 | |
| Download: ML20087J043 (10) | |
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Consumels power s.
ca 0
Vice Presu * - Projects, Engineering l
and Constn n
oeneral off ces: 1945 West Parnall Road, Jackson, MI 49201 * (517) 78& O453 March 16, 1984 80-09 #13 Mr J G Keppler, Regional Administrator US Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 j
MIDLAND NUCLEAR ENERGY CENTER DOCKET NOS 50-329 AND 50-330 LOW ALLOY QUENCHED AND TEMPERED BOLTING lls INCHES AND GREATER IN SUPPORT OF SAFETY RELATED SYSTEMS FILE:
0.4.9.46 SERIAL:
28042
References:
J W Cook letters to J G Keppler, Same
Subject:
(1) Serial 10996, dated January 9, 1981 (2) Serial 11526, dated March 31, 1981 (3) Serial 13690, dated September 29, 1981 (4) Serial 14666, dated January 15, 1982 (5) Serial 16149, dated April 2, 1982 (6) Serial 17354, dated Mey 17, 1982 (7) Serial 17542, dated July 9, 1982 (8) Serial 19085, dated October 29, 1982 (9) Serial 20711, dated February 22, 1983 (10) Serial 20747, dated April 5, 1983 (11) Serial 23774, dated August 19, 1983 (12) Serial 26594, dated December 2, 1983 This letter, as were the referenced letters, is an interim 10CFR50.55(e) report concerning the subject bolting. Attachment 1 provides a current status and the details of the LAQTS material evaluation that is currently taking place.
Another report, either interim or final, will be sent on or before July 27, 1984.
ohh9 O
PDR JVC/HSt.,/lr OC0384-0012A-MP01
' MAR 1 0 1984' gg S7
2 Serial 28042 80-09 #13
Attachment:
(1) MCAR 45A, Final Report; MCAR 45B, Interim Report 11, dated February 27, 1984 CC RJCook, NRC Resident Inspector Midland Nuclear Plant HRDenton, NRC Office of NRR Document Control Desk, NRC Washington, DC INPO Records Center l
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OC0384-0012A-MP01
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3 Serial 28042 80-09 #13 OM/0L SERVICE LIST Mr Frank J Kelley Atomic Safety & Licensing Attorney General of the Appeal Board State of Michigan U S Nuclear Regulatory Commission Ms Carole Steinberg, Esq Washington, DC 20555 Assistant Attorney General Environmental Protection Division Mr C R Stephens (3) 720 Law Building Chief, Docketing & Services Lansing, MI 48913 U S Nuclear Regulatory Commission Office of the Secretary Washington, DC 20555 Mr Myron M Cherry, Esq Suite 3700 Ms Mary Sinclair Three First National Plaza 5711 Summerset Street Chicago, IL 60602 Midland, MI 48640 Mr Wendell H Marshall Mr William D Paton, Esq RFD 10 Counsel for the NRC Staff Midland, MI 48640 U S Nuclear Regulatory Commission Washington, DC 20555 Mr Charles Bechhoefer, Esq Atomic Safety & Licensing Atomic Safety & Licensing Board Panel Board Panel U S Nuclear Regulatory Commission U S Nuclear Regulatory Commission Washington, DC 20555 Washington, DC 20555 Dr Frederick P Cowan Ms Barbara Stamiris 6152 N Verde Trail 5795 North River Road Apt B-125 Rt 3 Boca Raton, FL 33433 Freeland, MI 48623 Mr Fred C Williams Dr Jerry Harbour Isham, Lincoln & Beale Atomic Safety & Licensing 1120 Connecticut Ave, NW, Suite 325 Board Panel Washington, DC 20036 U S Nuclear Regulatory Commission Washington, DC 20555 Mr James E Brunner, Esq Mr M I Miller, Esq Consumers Power Company Isham, Lincoln & Beale 212 West Michigan Avenue Three First National Plaza Jackson, MI 49201 52nd Floor Chicago, IL 60602 Mr D F Judd Mr John Demeester, Esq
'abcock & Wilcox Dow Chemical Building 20 Box 1260 Michigan Division Lynchburg, VA 24505 Midland, MI 48640 l
Mr Steve Gadler, Esq Ms Lynne Bernabei 2120 Carter Avenue Government Accountability Project St Paul, MN 55108 1901 Q Street, tai l
Washington, DC 20009 l
OC0384-0012A-MP01
Serial 280h2 Bechtel Associates Professional Corporation 80-09 #13 l
143744 I43748 i
SUBJECT:
MCAR 45A, Final Report MCAR 458, Interim Report 11 DATE:
February 27, 1984 PROJECT:
Consumers Power Company Midland Plant Units 1 and 2 Bechtel Job 7220 Introduction The concerns discussed in this report address the hardness values of the anchor and connecting studs for the reactor coolant pump (RCP) cnubbers.
On November 26, 1980 Consumers Power Company expanded the 10 CFR 50.55(e) report to include, as potentially reportable, all low-alloy quenched and tempered steel (LAQTS) bolting materials 1-1/2 inches in diameter and larger used in support of safety-related systems.
In MCAR 45B, dated December 17, 1980, this scope was expanded to include review of 7/8-inch and larger safety-related LAQTS bolting material.
MCAR 45A was issued as a Final Report on August 5,1982.
The MCAR ASA report has been reissued as an attachment to this report and will be carried as an attachment until this MCAR is complete.
Investinative Action MCAR ASA:
Final Report (see attachment)
MCAR ASB Consumers Power Company is leading the investigation required by this NCAR.
Commonwealth Associates, Incorporated (CAI) of Jackson, Michigan, which is under contract to Consumers Power Company, has reviewed safety-related purchase orders and identified those purchase orders for LAQTS bolting and/or component support material.
CAI has also gathered data that are being used in evaluating the LAQTS materials.
I Most of the review being conducted on the LAQTS bolting and component support materials consists of field hardness testing. This testing is being performed by consumers Power Company and CAI.
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t43744 Bechtel Associates Professional Corporation MCAR 45A, Final Report i43748 MCAR 458. Interim Report 11 Page 2 Science Applications Incorporated (SAI) of Palo Alto, California, has been retained and has developed a sampling plan to determine the quantity of items to be tested. SAI has revised the sampling plan as a result of the additional materials identified by CAI.
Aptech Engineering Services has been retained to assist in evaluating the LAQTS materials purchased by identifying which materials are LAQTS and require testing. Aptech has developed a generic evaluation methodology (Report AES-8010220, dated July 1983 transmitted to the NRC on December 2, 1983, via Consumers Power Company letter, Serial 26594, l
J.W. Cook to J.G. Keppler) that establishes hardness limits for LA9TS materials. For bolting materials that exceed the established hardness limits, the methodology provides allowable stresses for preventing stress corrosion crack growth and brittle fracture. Guidelines are also given for evaluation of soft material for tensile-ductile failure.
Based on preliminary hardness test results, approximately 30 bolting material purchases were identified that appeared to contain material considerably softer than the hardness limits established by Aptech.
Further evaluation and testing on a portion of these materials by the Consumers Power Company laboratory indicated that the bolting materials were actually within the acceptable hardness limits. The differences were determined to be due to the existence of a decarburized layer that had not been completely removed during field testing. The hardness test procedure has been modified to prevent future difficulties due to erroneous data. The retesting of the remaining portions of these 30 bolting material purchases with the decarburized layer removed has been completed.
The discovery of the erroneous hardness data resulting from decarburization raised the following two concerns for previously collected hardness data.
a.
Bolting materials that had been tested and appeared to be below established hardness limits may actually be within the limits.
b.
Bolting materials that had been tested and appeared to be above or within established hardness limits may actually be harder than the first hardness tests indicated.
As a result of these concerns, a retest sampling program was developed with SAI to identify previously collected hardness data that are suspect; this program is complete. As a result of this program, bolting material l
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I43744 Bechtel Associates Professional Corporaton NCAR 45A, Final Report MCAR ASB, Interim Report 11 143748 page 3 purchases that require additional retesting to correct data errors due to decarburization have been identified. This additional testing is currently being accomplished; a March 15, 1984, completion date is anticipated.
preliminary review of hardness test data indicates that, of approximately 500 unique material deliveries that have been hardness tested to date, approximately 250 deliveries contain material of hardness outside the ranges established by Aptech (transmitted to the NRC on April 5, 1983, via Consumers Power Company letter, Serial 20747, J.W. Cook to J.G. Keppler). These material deliveries have been identified on a nonconformance report and are being placed on hold pending final evaluation of test data and implementation of corrective action.
The majority of the hardness testing has been completed.
However, some purchases of bolting material have not been located for hardness testing. To ensure location and testing of these items, a program has been developed to inventory all relevant applications that use bolting materials 7/8 inch in diameter or larger. The completed inventory lists will be used to identify safety-related locations of bolting requiring i
hardness testing. The inventory lists will also be used to locate remaining portions of safety-related materials tested that do not meet the established hardness limits.
Corrective Action MCAR 45A: Final Report (see attachment) i MCAR 45B The recommended corrective action for the bolting deliveries described under Investigative Action is to locate and verify by evaluation the acceptability of the material for each specific installation or replace the suspect bolting. This effort is being tracked under CpCo NCR M01-9-3-289.
A case-by-case evaluation of bolting located by this NCR [ bolting is located using a field tagging review (FTR) form) is currently being performed by Bechtel engineering. To date, based on 20%
evaluation of anticipated FTRs, results indicate that these bolting installations are acceptable for use. A generic solution to use grouted anchor bolts that use LAQTS material as installed has also been developed.
Quality control receipt inspection was revised to include a semple hardness testing of LAQTS bolting / component support materials.
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Bechtel Associates Professional Corporation 143744 MCAR 45A, Final Report MCAR ASB, Interim Report 11
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Page 4 Safety Impilcations NCAR 45A:
Final Report (see attachment)
MCAR 45B Bolting purchases have been identified that contain material that hardness tested outside the ranges established by Aptech. Therefore, it must be assumed that these bolting materials could fall during operating or accident conditions. The disposition of the suspect materials will preclude any adverse safety implications.
Reportability This condition relative to the RCP snubber studs was identified as "potentially reportable" by Consumers Power Company to the NRC under 10 CFR 50.55(e) on November 25, 1980.
MCAR ASB Submitted by: _
E.B. Poser Project Engineering Manager W
l Approved by:
T.E.
nson Chie ivil En ineer M
44
^
Approved by:
-E.H. Smit h 3
Engineering Manager concurrence by:
fa r M.A. Dietrich#
Project Quality Assurance f
psb]q Engineer o
M PVR/AVD/brb8(C)
Attachment:
MCAR ASA Final Report 0159u
I h 37 4 53echtel Associates Professiorial Corporation 777 East Eisenhuwer Parkway I4374a Ann Arbor,McNgan as uswees P.O. Son 1000. Ann Arbor, M crusan 48106 MCAR 45A Final Report 5UBJECT:
DATE:
August 5, 1983 (Reformatted and resigned November 18, 1983) 1 PROJECT:
Consumers Power Company Midland Plant Units 1 and 2 Bechtel Job 7220 Introduction The discrepancies discussed in this report concern the hardness vaises of the anchor and connecting studs for the reactor coolant pump (RCP) enubbers.
Backaround 2-1/4, 2-1/2, 3, and 3-1/2 leches in The RCP snubber anchor studs are diameter and vary in length from 3 feet, 5 inches to 7 feet,1 inch.
They are embedded in the secondary shield wall and the refuellas canal Also included are 2-inch and 2-1/4-inch-diameter connecting studs wall.
approximately 1 foot, 10 inches long that connect the snubbers to a The anchor studs are in place. The structural steel transition piece.
snubbers restrain the RCPs during seismic and/or loss-of-coolant accident The studs were purchased from various vendors during 1977 (LOCA) events.
and 1978 by Bechtel construction in accordance with either ASTM A 354 Grade BD, or ASTM A 540, Crade 323, Class 3.
They were intended to be tensioned to a preload up to 96 kol to maintain the specified snubber Prior to tensioning, to spring rates under all loading conditions.
ascertain that the studs could withstand long-term loads of this magnitude without becoming susceptible to stress corrosion cracking, Consumers Power Company requested Telodyne Engineering Services (TES) to conduct hardness tests on the exposed end of the embedded and connecting
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TES conducted these hardness tests from November 21 through studs.
The test results showed that 207 stude of 384 tested November 23, 1980.
are outside the range of hardness specified by the ASTM specifications.
Investimative Action
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.Aptech Eng'insering Services of Palto Alto, California, was retained by Consumers Power Company to review the hardness data taken by TES, and to evaluate the effect of the measured hardnesses on the ability of the Based on studs to withstand preload, operating, and accident loadings.
preliminary Aptech evaluations, it was decided to lower the required stad preload (to a maximum of 12 ksi) to preclude failure because of stress corrosion cracking. subsequently, Aptoch has provided Report AES-41-08-79 (which was transmitted to the NRC via Consumers Power Company letter, serial 17354, 5/17/83). In the development of a genaric evaluation methodology (in support of MCAR 458), it was found that ABS-81-08-79 was l
unconservative (by about 6%) in that development of fracture toughness limited allowable stresses; therefore, the allowable preload 0494u
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Bechtel Associates Professional Corporation NCAR 45A Final Report 143748 page 2 and accident stresses of AES-81-08-79 have been reevaluated. Based on this reevaluation of allowable stresses, the lowest maximum allowable l
l preload for any of the RCS snubber anchor bolts is 42.9 ksi. Therefore, the required 12 ksi preload is less than the allowables la the Aptoch report and is acceptable. Instructions were issued to construction to preload the stude to 9 ksi, a value lower than the maximum permissible.
A tolerance of 13 kol is allowed.
This preload value, when reduced by temperature and relaxation losses, etceeds 3 ket, a value in excess of the minimum preload of 1.5 kat required by Babcock & Wilcox (B&W) during operatloa. New spring rates have been submitted by techtel to B&W. B&W is proceedlag with the new I
seismic and LOCA analysis of the reactor coolant system. ITT Grinnell, supplier of the snubbers, has also been informed of the change la the preload. Crinnell stated that there is no effect on the snubbers or on the spring rate of the snubbers themselves.
The Aptech report noted above also contains an assessment of the allowable accident stresses of the RCp snubber anchor bolts. Based on thic report a-1 on the reevaluated allowable accident stresses, the allowable stress limits for operation and short-duration loading are available. Calculations have been prepared and the results indicate that the bolt stresses, bassd upon the capacity of the snubbers, are acceptable when compared to the Aptoch allowables.
procurement documentation packages for these studs have been reviewed.
All necessary corrective actica was completed and a report issued. No additional action is required.
Corrective Action Construction has been instructed to preload the snubber studs to 9 i 3 kel. A procedure was developed by R&W construction to ensure that the stude are tensioned as required. This work has been completed for Units 1 and 2.
Engineering has made a comparison of the calculated anchor bolt stresses with the Aptoch allowable stresses. These stresses, based on the capacity of the snubber, which limits the loading on the studs, are within the Aptoch allowable limits. All corrective actions under NCAR 45A are considered to be complete.
Safety Imo11 cations If the subject studs were tensioned according to the original design requirements, there may have been a safety deficiency la that some of the studs could have failed because of stress corrosion cracklag. If uncorrected, this deficiency could have adversely affected the safety of l
Midland plant operations during the expected life of the plant.
0494u
I43744 Bechtel Associates Professional Corporation NCAR 45A, Final Report 143748 pag. 3 Resortabilltr This condition relative to the RCP snubber studs was identified as i*
"potentially reportable" by Consumers Power Company to the NEC under 10 CFR 50.55(e) on November 25, 1980.
N M (/- *.
Submitted by: '4.Y.'Regupathy p% civil Group supervisor Approved b E'.B. Poser Project Engineering Manager Concurrence by:
T.E.gjlinson Chief Civil Eng neer MiLCO Concurrence by:
E.R. Smith Engineering Manager Concurrence by:farm.A.Diettig Project quality Assurance Engineer PVR/AVD/beb8(C).
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