ML20107A613
| ML20107A613 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/13/1985 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| REF-GTECI-A-36, REF-GTECI-SF, RTR-NUREG-0612, RTR-NUREG-612, TASK-A-36, TASK-OR 2NRC-5-022, 2NRC-5-22, NUDOCS 8502200052 | |
| Download: ML20107A613 (13) | |
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'Af 41 787 5 1 (412) 923-1960 Nuclear Construction Division Telecopy (412) 787-2629 Robinson Plaza, Building 2. Suite 210 Pittsburgh, PA 15205 February 13, 1985 United States Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Mr. George W. Knighton, Chief Licensing Branch 3 Of fice of Nuclear Reactor Regulation
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Do cke t No. 50-412 Additional Information on Draf t SER Outstanding Issue 136 Gentlemen-t Conversations with your staff have indicated that additional informa-tion is required to complete your review of the control of heavy loads (Outstanding Issue 136). Additionst information is attached to this letter to address the following items:
1.
Design comparison of special lif ting devices to ANSI hl4.6-1978 2.
Technical specification limits 3.
Shield plug design This completes the Duquesne Light Company response to this outstand-ing issue.
DUQUESNE LIGHT COMPANY By E.(J. Woolever Vice President KAT/wjs Attachments Mr. B. K. Singh, Project Manager (w/a) cc:
Mr. G. Walton, NRC Resident Inspector (w/a)
SUBSCRIBED AND S TO BEFORE ME THIS
/J M DAY OF
/ eM/_.
, 1985.
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N tary Public 8502200052 850213 ANITA ELAINE REITER, NOTARY PUBLIC g
PDR ADDCK 05000412 PDR ROBINSON TOWNSHIP, ALLEGHENY COUNTY E
MY COMMISSION EXPIRES OCTOBER 20,1986
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' United States Nuclear Rsgulatory Commission Mr. Gaorge W. Knighton, Chief
-Page 2 COMMONWEALTH OF PENNSYLVANIA
)
)
SS:
COUNTY OF ALLEGHENY
)
On this
/J day of
/ f[5, before me,
a Notary Public in and for said Commonwealth a County, personally appe ared E. J. Woolever, dio being duly sworn, deposed and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoirg Submittal on behalf of said Company, and (3) the statement s set forth in the Submittal are true and correct to the best of his knowledge.
~
Notary Public ANITA ELAINE REITER, NOTARY PUGUC ROBINSON TOWNSHIP, ALLEGHENY COUNTY MY COMMISSION EXPlRES OCTOBER 20,1986
ATTACHMENT 1 Special Lifting Devices (NUREG-0612, Section 5.1.1, Guideline 4)
The December 22, 1980, Generic Letter from Mr. Eisenhut stated in part:
" Verification that lifting devices identified in 2.1.3-c, above, comply with the requirements of ANSI N14.6-1978, or ANSI B30.9-19 71 as ' appropriate.
For lifting devices where these s t anda rd s, as supplemented by NUREG 0612, Section 5.1.1(4) or 5.1.1(5), are not
- met, describe any propo sed alternatives and demonstrate their equivalency in terms of load-handling reliability."
The 'following sdditional information is provided on this subject:
ANSI N14.6-19 78 (Special Lifting Devices for Shipping Containers Weighing I,000 Pounds or More for Nuclear Materials),
Section 3.1, Designer's Responsibilities A.
Limitations on the use of Lif ting Device (3.1.1)
Response
The s tanda rd states that the designer of the lif ting device is to design specification containing in part a definition of prepa re a perfo rmance criteria, requirements for drawings and ma t e ri als,
inspection and testing to be performed and limitations on the use of the device.with respect to temperature, corrosive environments, etc..
At the time these devices were procured and fabrica ted, a require-ment for a de sign specification did not exist.
The des igner, the Westinghouse Electric Corporation, did not write a design specifica-tion concerning these specfic requirement s.
However, assembly and detailed manufacturing drawings and purchasing documents contain the following information:
- Material specification for most of the critical load path-items to ASTM, ASME specifications or special listed requirements (See B below)
- Welding, weld procedures, and welds to be in accordance 'with ASME Boiler and Pressure Vessel Code - Section IX
- Special NDT for specific critical load path itess to be pe rfo rmed to written and appr oved procedures in accordance with ASTM or specified requirements
- All coatings to be performed to strict compliance with specified requirements
- Letters of compli ance for materials and spe cifications were required for. verification with original specifications No limitations were identified as to the use of these devices under specific environsental condit ions.
The conditions under which the
lifting devices are stored and used were considered and accounted for.in their design and fabrication.
This can be demonstrated by the use of protective coatings applied in accordance with the designers specified requirements.
B.
Identification of Critical Components and Definition of Critical Characteristics (3.1.2)
I
Response
A critical items list of parts and welds has been prepared for the reactor vessel head lift rig and the reactor vessel internals lift l'
rig and. the RCP motor lift rig.
The information contained on this list includes material identification and the applicable volumetric and surface inspections that were performed in the fabrication of these special lif ting devices.
In some instances, non-destructive testing was not specified since the material selection and strength result in very low tensile stresses and thus, non-destructive testing was not justified.
The material selection for most critical load path items was made to ASTM, ASME, or special material requirements.
However, the non-2 design items of the RCP motor lift sling were selected based on their load ' carrying capabilities.
These include "U"
bolts, wire rope slings, shackles,. turnbuckles, and hooks. The material require-ments were supplemented by Westinghouse imposed non-destructive testing, and/or - special heat treating requirements for all of the critical items.
Westinghouse required all welding, welders, and weld procedures to be in accordance with ASME Boiler and Pressure Vessel Code Section IX for carbon steel welds. They also required a certificate, or letter of _ compliance that the materials and
. processes used by the manu f acturer were in accordance. wi*h the purchase order-and drawing requirement s.
Westinghouse also 3
performed final inspections on these devices and issued quality releases.
C.
Signed Stress - Analyses which Demonstrate Appropriate - Margins of Safety (3.1.3)
. Response A stress analysis of - the 'special lif ting devices has been prepared by Westinghouse.
This analysis documents the adequacy of the special lifting devices in that they can perform their function within appropriate margins of safety.
The ANSI N14.6 criteria have been met for tensile and shear stresses.
D.
Ind'ication for Permissible Repair Procedures (3.1.4)
Response
i The standard states that the designer should indicate what ' repair.
procedures are permissible. The following guidance will be used for l
- repairs to these devices.
Any repair to these special lifting-devices is ; considered to be in the form of welding.
Should pins,
E bolts or other fasteners need repair, they should be replaced, in lieu of repair, in accordance with the original or equivalent requirements for material and non-destructive testing. Weld repairs and examinations will be performed in accordance with plant
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procedures.
ANSI N14.6 Section 3.2; Design Criteria A.
Use of Stress Design Factors of 3 for Minimum Yield Strength and 5 for Ultimate Strength (3.2.1)
Response
The load bearing members of the special lifting devices are capable of lifting three times the combined lifting weight of the design lift without generating a combined shear stress or maximum tensile stress within the lifting device in excess of the corresponding minimum yield strength of the materials of construction.
They also are capable of lifting five times that weight without exceeding the ultimate strength of these materials.
This has been documented in the stress report prepared for these devices.
The ANSI N14.6 criteria (3 for yield, 5 for ultimate) has been met for tensile and shear stresses.
High strength materials were used in these devices.
Although the fracture toughness was not tested, the materials used were selected based on their excellent fracture toughness characteristics.
However, in lieu of a different stress design factor, the ANSI N14.6 stress design factors of 3 and 5 were used in the analysis and the resulting stresses are cons ide red to be acceptable.
NUREG-0612, Article 5.1.1 (4) further states that the stress design factor should be based on the combined maximum static and dynamic loads that could be imparted on the handling device based on the ch arac-teristics of the crane which will be used.
The dynamic characteristics of the crane would be based on the main hook and associated wire ropes holding the hook.
Should the crane hook suddenly stop during li f ting or lowering of a load, a shock load could be transmitted to the connected device.
Because of the elasticity of the wire ropes, the dynamic factor for a typical containment crane is not not much larger than
- 1. 0.
The maximum design factor that is recommended by most design texts is a factor of 2.0 for loads that are suddenly applied.
The stress design factor of 3 fot yield strength from the ANSI criteria certainly includes consideration of suddenly applied loads for cases where the dynamic impact factor may be as high as 2.0.
B.
Similar Stress Design Factors for Load Bearing Pins, Links and Adapters (3.2.4)
Response
The stress design factors of ANSI N14.6 Sect ion 3.2.1 of 3 and 5 were used in the analysis and the resulting stresses were
E accept able.
This has been documented in the stress report.
Where necessary, the weight of pins was considered for handling.
r C.
Slings used Comply with ANSI B30.9-1971 (3.2.5)
Response.
The wire rope used on the RCP Motor Lif t Sling complies with ANSI B30.9-1971.
D.
_ Subjecting Materials to Dead Weight Testing or Charpy Impact Testing (3.2.6)
Res ponse Drop weight and Charpy impact tests were not required. However, all ma terial selection was based on its excellent fracture toughness characteristics.
ANSI N14.6 Section 3.3; Design Considerations A.
Design Shall Assure Even Distribution of the Load (3.3.4)
Response
assure even distribu-These special lif tig devices were designed to tion of the load.
B.
Retainers Fitted for Load-Carrying Components which may become Inadvertently Disengaged (3.3.5)
Response
' Locking plates, pins, etc. are used throughout these special lif ting devices.
C.
Verification that Remote Actuating ' Mechenisms Securely Engage or Disengage (3.3.6)
Response
Remote actuation is only used when engaging in the internals li f t rig with the int ernals.
Pos ition indication is provided from the operating platform.
ANSI N14.6 Section 4.1; Fabricator's Responsibilities i
i A.
Verify Selection and Use of Material (4.1.3)
Response
l The critical ~ load carrying members of these special lif ting devices were designated by Wes tinghouse, the designer, as requiring letters of compliance to document the use of the correct materials.
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d.
Compliance with Fabrication Practices (4.1.4)
Response
General good manufacturing processes were followed in the manuf ac-ture of these devices. Assembly and detailed manufacturing drawings contained information regarding the fabrication of these special lifting devices.
Westinghouse performed checks and inspections during various steps of manufacturing.
C.
Qualification of Welders, Procedures, and Operators (4.1.5)
Response
The manufacturer's welding procedures and non-destructive tes ting procedures, as well as personnel qual i f icat ions, were reviewed by Westinghouse.
D.
Provisions for a Quality Assurance Program (4.1.6)
Response
The manu f ac ture r's welding procedures and non-destructive testing procedures were reviewed by Westinghouse prior to use.
E.
Provisions for Identification and Certification of Equipment (4.1.7)
Response
Most' of the critical load carrying members require letters of com-pliance for material requirements.
In addition, Westinghouse pe r-formed checks and inspections during various steps of manufacturing.
F.
Verific'ation that Materials or Services are Produced Under Appropri-ate Controls and Qualifications (4.1.9)
. Response Westinghouse Quality Assurance pe rsonnel performed in process and final inspections on the materials, work and finished product.
Final Westinghouse review included visual, dimensional, procedural, cleanliness, personnel - qualifications checks, and the issuance of a quality release to ensure conformance with drawing requirements.
' ANSI N14.6 Section 5.1; Owner's Responsibilities A.
Implementation of a Periodic Testing Schedule and a System to Indicate the Date of Expiration (5.1.3)
Response
The special lifting devices at Beaver Valley Unit 2 will be used infrequently, normally only during refueling outages which will be occurring on a frequency of approximately 18 months. During refuel-ing outages, these devices may only be used for 2 to 3 lif ts each.
For this reason, it is considered impractical to implement a pe r i-odic testing schedule.
The ANSI Standard was wr tten for special i
lifting devices which could be used at a much greater frequency, where a periodic testing schedule would be appropriate.
In order to verify special lifting device capsbility of reliably
_ performing their function, procedures require a visual check of critical welds and parts prior to use and as an initial step when performing a lift.
B.
Provisions for Establishing Operating Procedures (5.1.4)
Response
Instructions on the use of special lif ting devices will be contained in plant refueling and maintenance procedures.
C.. Identification of Subassemblies which may be Exchanged (5.1.5), and D.
Suitable Markings (5.1.5)
Response
It is obvious, from their designs, that these rigs cre specific lif ting devices that can only be used for their intended purpose and
-that parts are not interchangeable.
Therefore, labeling each special lifting device for its intended purpose is not necessary.
.E.
Maintaining a Full Record of History (5.1.6)
Response
A record of' the _ history of the special lif ting devices is maintained in accordance with plant procedures. Records are available document-ing the inspections performed on these devices, pre-lift and during lift, as well as the completed procedures which were followed during their use.
If maintenance is required on these devi s,
plant procedures provide for the documenting of the repairs performed.
F.
Conditions for Removal from Service (5.1.7)
Response
Any special lifting device which has experienced any incident-r-
causing doubt as to its being able c7 pe rfo rm acceptably, or which has been damaged will be removed froc. service until it has been repaired or it has been demonstrated to be capable of performing its intended function. 'Ihese devices will not be > sed until the required
-visual inspections have been. performed in accordance with plant procedures.
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ANSI N14.6 Section 5.2_; Acceptance Testing A.
Load Test to 150% and Appropriate Inspections Prior to Initial Use (5.2.1)
Response
The special lif ting devices were load tested af ter field assembly to 125% macimum load followed by non-destructive testing of critical welds.
Load testing to 125% is considered adequate in view of the safety factors designed into these devices.
B.
Qualification of Replacement Parts (5.2.2)
Response
Replacement parts, should they be required, will be made of identi-cal or equivalent material and inspected as originally required.
ANSI N14.6 Section 5.3; Testing to verify _ Continuing compliance A.
Satisfying Annual Load Test or Inspection Requirements (5.3.1)
Response
These special lifting devices are used during plant refueling which will be approximately eve ry 18 months.
During plant operation, these devices are inaccessabte since they are permanently installed and/or remain in the cont ainme nt.
It is considered impractical to attempt to remove these devices from containment for load testing.
Likewise, load testig to 150% of the total weight be fo re each use would require special fixtures and is impractical to perform.
In order to demonstrate continuing compliance, a visual examination of critical welds and parts will be conducted prior to lif ting and at the initial lif t prior to moving to full lif t and movement. This will be accomplished by raising the load slightly above its support and holding it for 10 minutes.
During this time, critical welds and parts will be visually inspected.
If no problems are apparent, the lift will continue. Additionally, a non-destructive examination of major load-carrying welds will be performed as part of the ten year inservice inspection outage.
This testing interval is justified because of the low usage these special lifting devices receive during this period.
Non-destructive testing on an annual basis is not considered practi-cal for the following reasons:
- Access to the welds for surf ace examination is dif ficult.
These rigs are in contairment and some radioactive contamination may be present.
- All tensile and shear stresses in the welds are well within the allowable stresses.
- The items that are welded remain assembled and cannot be misused for any litt other than their intended function.
- To perform non-destructive tests would require the following which from an ALARA standpoint is not justified.
1.
Removal of contaminated paint around the area to be examined.
2.
Performance of either magnetic particle inspection or liquid penetract inspection 3.
Repaint Ing af ter testing is completed 4.
Clean-up of contaminated items
- The frequency of use and, therefore, the wear on the speci al lifting devices is much lower than fo r shipping containers fo r which the Standard was written.
Dimensional checking is not included since these structures are large and the results of dimensional checking would always be questionable.
Other checks on critical load path parts such as pins, are also not included since an examination of these items would require disassembly of the special lifting devices.
This ANSI standard was written fo r special lifting devices for shipping containers weighing 10,000 pounds or nore. Lifting devices for this application are typically far le ss complicated in design and, therefore, meeting this standard would be easily ach ieved.
Application of this part of the standard to the special lif ting devices at Beaver Valley is not considered practical. The activities as daacribed in this respose should meet the intent of the standard in determining that the lif ting device is capable of performing its intended function safely.
B.
Testing Following Major Maintenance (5.3.2)
Response
Any major maintenance which may be needed on these special lifting devices is cons idered to be in the form of welding.
Weld repairs will be performed in accordance with plant procedures. The repaired area will be non-destructively examined to determine acceptability of the repairs.
It will then be subjected to loading to the level expected to be carried within the repaired area and then another non-destructive examination will be performed.
C.
Testing After Application of Substantial Stresses (5.3.3)
Response
If the load-bearing components of these special lif ting devices have been subjected to stresses substantially in excess of those for which it was qualified, the following will be performed. Replaceable parts will be tested in accordance with approved procedures to determine if they are acceptable for continued use or they will be replaced as described in the respose to ANSI N14.6 Sect ion 5.2.2.
Welds will be non-de s t ruc t ively examined in accordance with plant
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procedures to determine if they are acceptable for continued use or they will be repaired and tested in accordance with the response to ANSI N14.6 Section 5.3.2.
D.
Ins pections by Operating (5.3.6) and Non-Operating or Maintenance Personnel (5.3.7) ivaponse Plant procedures require these special lifting devices to be visually inspected prior to use by maintenance pe rso nnel.
These devices are also visually inspected at critical welds while under load by holding the load slightly above its support for 10 minutes.
For any lift of a heavy load with a special lift device, present procedures provide for a Quality Control Inspector to provide sur-veillance of the lift activity. This includes proper installation of rigging and a visual inspection of critical welds on these devices.
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ATTACHMENT 2 Technical Specification Restriction on Loads Carried over the Spent Fuel Pool P
The BV-2 Draft Techt.ical Specification, Sect ion 3.9.7 for Ref ueling Opera-tions, has a 3,000 pound limit specified for loads that could be carried over the fuel pool when there are fuel assemblies s tored in the pool. This 3,000 pound limit is based on the combied weight of a fuel assembly, a fuel storage container, and the spent fuel handling tool.
The motor driven platform crane hoist has an interlock setting of less than 3,000 pounds.
Administrative procedures require that maintenance operations be carried out along a safe path away from the s pent fue l pool.
In these special cases, the hoist interlock can be overridden.
Analyses have been pe rformed which show that the re is no adve rse safe ty impact if a handling tool or a fuel as semb ly and its handling tool are dropped onto the fuel racks.
r ATTACHMENT 3 Concrete Shield Plugs The movement. of concrete shield plugs follows safe load paths.
These load paths - as discussed in FSAR Section 9.1.5 are utilized to preclude dropping heavy loads on safety-related equipment or spent fuel.
The integrity of removable concrete shield plugs during their movement is ensured by the provision - of a minimum factor of safety of four against pull out for the lifting inserts.
Therefore, adequate protection is provided against damage to safety related equipment.
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