ML20031D241
| ML20031D241 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 09/18/1981 |
| From: | Garrity J Maine Yankee |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20031D239 | List: |
| References | |
| RTR-NUREG-0612, RTR-NUREG-612 FMY-81-141, JHG-81-179, NUDOCS 8110130177 | |
| Download: ML20031D241 (20) | |
Text
,
2$2*i-179 MNRE mkjSARHEE I Aiornl0 P0l'/ER 00lRPAiW *
,uaugr,j,in"gj CE) W3 (207) 623-3521 0
Septemoer 18, 1981 FMY-81-141 lnited States Nuclear Regulatory Commission Washingten, D. C.
20555 Attention:
Office of Nuclear Reactor Regulations Mr. D. G. Eisenhut, Director Division of. Licensing
References:
(a)
License No. OFR-36 (Occket No. 50-309)
(b)
USBRC lettsr, O. G. Cisenhut to all Licensees of Operating Plants and fcplicants for Operating Licensees and Folcers of Construction Permits, dated December 22, 1980
/.c )
USNRC letter, D. G. Eisenhut to all Licensees and holders of Construction Permits, dated February 3,1981 (d)
USNRC letter to MYAFC, dated March 13, 1981 (e)
MYAFC letter (FMY 81-91) from R. H. Groce, dated June 15, 1981;
Subject:
Control of Feavy Loads
Enclosure:
(a)
Control of Heavy Loads, Section 2.1 submittal SUSJECT:
Control of Feavy Loads Cear Sir:
References (b), (c), and (d) required evaluation of heavy load handling equipment at Maine Yankee and requested a report of the results of this l
evaluation. Reference (e) provided Maine Yankee's intended schedule for i
submittal of this information.
l The information recuested in Section 2.1 of reference (d) is presentec in enc 1csure (a) numcered to correspcnd to the information request.
i This submittal is a summary of the detailed engineering analysis performed l
Dy Maine Yankee.
The analysis and inspections were conducted in accordance j
with the objectives and bases of the defense in-depth approacn outlined in Section 5.1 of NUREG C612.
i l
l Cection 2.2 cf reference (d) requests information on specific requirements for overhead handling systems cperating in the vicinity of fuel storage pcols.
In 1975, the Commissicn reviewed Maine Yankee's analysis of a postulated spent fuel cask drop accident in the spent fuel pool and ccncurred with cur evaluaticn that no safety related equipment was beneath the path fo:
l Cask travel.
8110130177 811006 PDR ADOCK 05000309 l
MAINE YANKEE ATOMIC POWE1 COMPANY United States Wclear Regulatory Commission Office of Nclear Reactor Regulaticns Page 2 Additionally, the yard crane (CR-3) was modified to improve reliability, incluoing addition of limit switches and a new main hoist equalizer sheave assembly to provide overload sensing of main hoist hook loads.
Limit switches were installed which prevent movement of any load over spent fuel in the pool.
The Commission concurred with the Maine Yankee review and stated that previsions tc prevent a postulated spent fuel shipping cask accident are acceptable. Maine Yankee contends that this last review is still valid ano that submission of additional information per reference (d), section 2.2 is unnecessary.
Maine Yankee is currently analyzing section 2.3 of reference (d) on specific requirements of overhead handling systems cperating in the containment. Upon identifying the scope and necessary time required to complete this review, we will forward the commission a proposed submittal date that will allow for ccmpletion of a comprehensive and quality submittal.
Section 2.4 requests information en specific requirements for overhead handling systems operating inplant areas containing equipment required for reactor shutdown, core cecay heat removal, or spent fuel pool cooling. Maine Yankee's respense to section 2.1 (Enclosure A) justified the exclusion of all overhead handling systems at the plant.
Our detailed engineering inspection of plant arrangements has shown that sufficient redundancy exists such that a load drop would not result in the loss of critical safety related functions.
No further response to section 2.4 is considered necessary.
We trust that this informatin will be satisfactory, however, should you require additional information, please contact us.
I Sincerely, MAINE YANKEE ATCMIC POWER COMPANY
[
.bnn H. Garrity, Direqtor Nuclear Engineering ano Licensing CHG/plb
ENCLOSURE A CONTROL OF MAVY LOADS AT NUCLEAR POWER PLANTS - NUREG 0612 2.1.1 REPORT TE RESULTS OF YCUR REVIEW OF PLANT ARRANGEMENTS TO IDENTIFY ALL OVEREAD HAPOLING SYSTEMS FROM WHICH A LOAD DROP MAY RESULT IN DAMAGE TO ANY SYSTEM REQUIRED FOR PLANT S}-UTDOWN OR DECAY HEAT REMOVAL (TAKING NO CREDIT FOR ANY INTERLOCKS, TECHNICAL SPECIFICATIONS, OPERATING FROCEDURES, CR DETAILED STRUCTURAL ANALYSIS').
Safe shutdown equipment includes safety related equipment and associated subsystems that would be required to Dring the plant to hot shutdown conditions or provide continued decay heat removal following the oropping of a heavy load. Safety functions tnat should be preserved are:
to maintain reactor coolant pressure boundary; capability to reach and maintain subcriticality; and removal of decay heat.
The following Maine Yankee systems are required to accomplish these safety functions:
Function Equipment Required A.
Maintain Reactor Coolant Reactor Coolant System, and portions of Pressure Boundary Safety Injection, Charging, Pressurizer surge and spray piping and Residual Heat Removal (R$ ) piping.
B.
Capability to Reach and Control Rods, Chemical and Volume Maintain Subcriticality Control System for Baration.
C.
Steam Generator a) Steam to Atmosphere Safety and Steam Dump valves.
I b) One auxiliary feed pump; (3 pumps available).
2.
R $ (below 400 psig)
(1 of 3 pumps req'd) plus PCCW (1 of 2 pumps reg'd) or SCCd (1 of 2 pumps req'd) plus service water (1 l
of 4 pumps required).
3.
Fuel Pool Cooling Pumps (1 of 2 pumps reg'd) plus PCCd (1 of 2 pumps req'd) plus service water (1 of 4 pumps required).
l
Enclosure A Page 2 of 18 For each of the systems or components identified above, all piping and power cables necessary to carry out the function must be intact for the system to carry out,its function unless a non-associated redundant train is availat,le.
For each of tae functions critical volumes exist in the areas immediately adjacent to each system and rising vertically to the tcp of the structure.
If a crane or hoist hook is capable of peretrating these critical volumes, then the potential for a load drop to darrage critical equipment exists.
The folloring critical volumes exist at Maine Yankee:
Safe Shutdown System Critical Volume A.
Reactor Coolant Systems and Containment 81dg.
associated portions of safety injection, charging,pzr.
surge and spray piping and RER piping.
B.
Control Rods Containment Bldg.
Containment Penetration Area, Protected Cable Vault, Protected Caole Tray Room, Control Room Cable Clase.
C.
Chemical and Volume Control Components & Piping:
Containment Bldg.
System and PA8 Electrical Cables: PAB, Protected Cable Vault, Control Rocm Cable Chase, Protected Cable Tray Room.
O.
Steam Cenerators and Steam Containment Bldg., Steam and Feed to Atmosphere Valve House.
Safety and Steam Dump Valves E.
Auxiliary Feed Pumps Ccmponents and Piping:
Containment Auxiliary Feed Pump Rocm, Steam and Feed Valve House.
Electrical Caoles:
Protected Cable Tray Room, Centrol Room Caole Chase, Protected CaDie Vault.
F.
Resicual Fr.at Removal Components and Piping:
Containment, Spray Pump Bldg.
Electrical Caoles: Protected Cable Tray Rocm, C;ntrol Room Cable Chase, Protected Cable Vault, Steam and Feecwater Velve House, Containment Spray Pump auilding.
Enclosure A c ge 3 of 18 a
G.
Primary Component Cooling /
Components and Piping: Northwest Secondary Component Cooling corner of Turbine Blcg., Containment Spray Pump Bldg.
rotected Cable Tray Electric Cables: o Room, Control Roou Cable Chase.
Protected Cable Vault, Turbine Bulloing.
H.
Service Water PJmps Components and Piping:
Circulating Water Pung House, Turbine Building.
Electric Cables: Protected Caole Tray Room, Control Room Cable Chase, Turbine Building, Circulating Water Pump House.
Overhead weignt handling systems capable of operating within these critical volumes consist of:
A.
Reactor Containment Polar Crane (G-1) 8.
Turbine Hall Crane (G-2)
C.
Fuel Bldg. Yard Crane (G-3)
D.
PAB Holst for Lower Floors
( G-5, MR-5)
E.
Auxiliary Feed Pump Room Manorails F.
PAB Holst for Upper Flcors (G-12, MR-12)
G.
Trolley for Circulating Water Pump House H.
Monorails and Hoists for Steam and Feed Valve House I.
Fuel Building Crane (CR-5)
J.
Containmen: Annulus Manual Holst and Monorail (CR-19)
The following areas may be excluded from further consideration since no installed weight hancling systems exist in these areas:
1.
Control Room Cable Chase 2.
Protected Cable Vault 3.
Protected Cable Tray Room 4.
Containment Spray Pump Building 5.
Containment Penetration Area l
Enclosure A o ge 4 of 18 a
2.1.2 JUSTIFY TE EXCLUSION OF ANY OVERHEAD HAM) LING SYSTEM FROM TM ABOVE CATEGORY, BY VERIFYING THAT TERE IS SUFFICIENT PHYSICAL SEPARATION FRCM ANY LOAD-IMPACT POINT AND ANY SAFETY-RELATED CDMPONENT, TO PERMIT A DETERMINATION BY INSPECTION THAT NO EAVY LOAD OROP CAN RESULT IN OMAGE TO ANY SYSTEM.
A.
Turbine Hall Crane The critical volume areas in the Turbine Hall are limited to the entire north wall and an area in the northwest corner of the ouilcing acave the Primary Component Cooling (PCC) and Secondary Component Cooling (SCC) systems.
The critical volume al mg the nortn wall contains the power cabling for the PCC and SCC syst.s. and the service water pumps.
These caole trays run near the wall at about the 39' elevation well below the turbine operating floor which is at the 61' elevation.
This critical volume is not capaDle of being penetrated by eit.C the main or auxiliary necks since the hack travel limit is spproximately 17' from the wall.
The primary and secondary ccmponent cooling pumps are also outside of the hook travel limit and situated at the 21' elevation well separated from the crane hooks.
Portions of the piping and the heat exchangers for these two systems are within a critical volume which can be penetrated by the crane hook.
The hook however is not capable of being lowered through the turbine operating floor to the 29' level where the heat exchangers are located or the 35' level where portions of the system piping are locaced due to the absence of removable concrete slabs.
Loads are never handled directly over the components of r
concern.
The only cancern would come from a heavy load which might drop l
with sufficient kinetic energy to penetrate the concrete slab ano steel I
girders supporting the operating floor at the 61' elevation.
I While the plant is operating, heavy loaos are rarely handled within this critical volume. During outage situations, heavy loads are moved through the critical volume and stored on the 61' level inside the volume.
The largest load which could be potentially stored in this area is.he main generator rotor which weighs approximately 144 tons.
This load is handled about every two or three outages and is controlled such that it is never raised 6-8" above the floor in order to limit the potential energy of the load.
The normal laydown location is alongside the generator casing in which case it would not be within tne critical volume. Because of the infrequency of hanaling this load and the protection provided the systems of concern by the.)uilding structure and due to administrative procedures used in moving the load, it is not considered credible that a load drop could penetrate the 61' elevation and impact safe shutdown equipment.
If however, something did happen resulting in damage to these components, redundant trains are available to fulfill the decay heat removal function of the Primary and Secondary Component Cooling systems.
Cooldcwn to cold shutdown could be accomplished using water from the fire pond for cooling.
l
Enclosure A Nge 5 of 18 The Residual Heat Removal System heat exchangers, one Residual Heat Removal System pump, and the diesel driven fire pump could be used since they would remain undamaged if a load drop occurred within the Turbine Hall.
Fbse connections are available on the shell side of both heat exchangers which permit fire pond water to be used to remove heat. Less than 400 gpm per heat exchanger would me required.
This flow rate can be continued for at least 2 months using the minimum amount of availaole water from the fire pond and the Montsweag Brook Reservoir.
This cocidown path assures the ability to cool to a cold shutdown concition with reactor coolant system temperature well below the Technical Specifications requirement of 2100F.
Repair measures to restore a damaged PCC and SCC system could be completed in this time frame.
Following the necessary damage centrol measures, the Service Water / Primary Component Coaling Water / Residual Heat Removal system's heat removal path would >e restored.
Service water pip W the primary and secondary component heat exchangers also is meated within the Turbine Hall critical volume.
The piping run travels a the heat exchangers beneath the ground floor 21' elevation and is thu provided additional protection.
In addition, the design of the Service Water System insures operability following a single piping failure due to a heavy load drop.
The system is normally l
linedwap with the pump discharge cross <onnect isolation valve closed and the heat exchanger supply cross-connect isolation valve open so that a rupture in either the north or south supply header will not seriously affact plant operation.
Check valves in the supply headers prevent backflow through the ruptured header, and the unaffected header has sufficient capacity to meet system requirements.
Header ruptures downstream of the check valves can be isolated by closing manually operated isolation valves.
If a load drop did result in loss of the service water then the residual heat removal heat exchangers, one Residual Heat Removal System pump and the diesel driven fire pump could be used as previously described as they would be unaffected by a load i
drop that impacted service water piping within the Turbine Hall.
The Turbine Hall Crane, CR-2 receives a detailed inspection prior to any heavy load lift and prior to a refueling outage.
This detailed inspection is performed by an authorized Whiting Crane representative, the vendor for the Turoine Hall Crane.
This inspection includes examination of all compenents of the rcpe reeving system with close attention given to the hoisting ropes, limit switches and brakes.
All deficient compcnents are replaced or repaired prior to any lift.
Cetailed engineering inspection of the critical volume associated with the safe shutdown systems within the Turcine Hall along with tne acministrative controls applied to the Turbine Hall Crane provides acequate safety for the associated safe shutdown systems.
No further analysis of this crane is considered necessary.
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a Enclosure A c ge 6 of 18 a
8.
Fuel Building Yard Crane ( m -3)
In 1975 the Commission reviewed Maine Yankee's analysis of a postulated spent fuel cask drop accident in the spent fuel pool and concurred with the plant evaluation that no safety related equipment was beneath the path for cask travel.
The crane was modified to improve its reliability including addition of limit switches and a new main hoist equalizer sheave assembly to provide overload sensing of main hoist hook loads.
Limit switches were installed which prevent movement of any load over spent fuel in the pool.
The Commission concurred with the Maine Yankee review and stated that provisions to prevent a postulated spent fuel shipping cask accident are acceptable. Specific questions 5.17 and 9.14 in Volume III of the FSAR also address the yard crane.
Analysis has shown that even if a cask drop resulted leakage from the pool would be minimal and well within the capacity of either of the two primary water transfer pumps.
No further analysis of this crane is considered necessary ct this time.
C.
PA8 Hoist for Lower Floors (G-5, MR-5)
Boration is normally accomplished with the use of any one of three charging pumps located in the Primary Auxiliary Building.
These pumps i
are not required to achieve a hot snutdown condition.
However, to achieve a cold shutdown condition, boration would ce required.
The critical volume associated with the 21' level of the Primary Auxiliary Building surrounds the three charging pumps, their power cables, charging pump lube oil power caoles, and the Chemical and Volume Centrol System piping associated with boration to support the capability to reach and maintain suberiticality.
The power cable to the charging pumps runs through a 4" steel conduit imbedded mid-way througn the 18" tnick floor slab at the 21' elevation.
The monorail runs parallel to tne power cables but is horizontally separated by aoout 2' such tnat a load drop could not impact directly on the concrete above the conduit.
The power cabling for the charging pump lube oil pumps is routed through a cable tray running parallel to the monorail.
This tray is level with the monorail and thus not susceptible to damage from a load drop.
The cables leave the tray and are rcuted above the monorail to each of the charging pump cubicles, therefore no electric cabling for the charging pumps is suoject to load drop damage.
Brancnes of the monorail are located above the centerline of each of tne pumps to facilitate their installation and removal.
Each pump is enclosed in its own cubicle with concrete partitions separating the pumps.
Access to the charging pump cuoicle is aoministratively controlled by a locked barrier.
The only loads tht.t would ever be hoisted by the menorail are the cnarging pumps the:aselves.
Chemical and Volume Control System piping associated with caration does not pass directly beneath the monorail at any point.
Enclosure A Page 7 of 18 If a charging pump was being removed for maintenance and did drop it is not considered likcly that it could fall such that it would penetrate the concrete wall damaging another ch1rging pump.
In any case, there would still be an additional cnarging pump available.
Another alternative would be to use the auxiliary charging pump which has sufficient vertical and horizontal separation so that neither the pump itself or the power cables would be subject to damage involving the main cnarging pumps.
In the extremely unlikely event that a load drop in the Primary Auxiliary Building did somehow cestroy the power cables to the auxiliary charging pump and the main charging pumps, conservative estima:es show that power cables to the auxiliary charging pump (480 V) or to a main charging pump (4160 V) could be re-run in 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, after which cooldown could begin.
It is important to note that the plant can be maintained in a safe hot shutdown condition until such rerouting is accomplished.
Detailed engineering inspection of tnis critical volume indicatas that sufficient protection is provided such that alternative safe shutdown equipment is always available.
No further analysis of monorail MR-5 and hoist CR-5 is considered necessary.
D.
Auxiliary Feed Pumo Room Monorails The auxiliary feed pumps are required to support decay heat removal.
Decay heat removal is accomplished by ventin( steam to the atmosphere thrcugh the steam generator safety valves and the atmospheric steam dump valve.
Feedwater inventory is normally maintained in the steam generators with the use of either cne (1) of two (2) electric driven auxiliary feed pumps, P-25A or P-25C. Both of these pumps are located in a tornado protected room adjacent to the containment.
1 The monorails in this room are directly above each pump.
They are used only for installing / removing the associated pump.
Piping and caoling to the pumps are located such that a load drop would not impact directly on the piping or cabling.
If the pump was being rigged out for repair it would alreaoy be out of commission and not be relied upon to maintain l
feedwater inventory. Either the otner electric pump or the steam driven auxiliary feed pump located in the steam and feed valve hcuse, could provice the necessary makeup water.
Coolccwn would be accomplished by venting steam to atmospnere through the steam generator safaty valves and the atmospheric steam dump valve.
The plant can be cooleo to approximately 212 to 2. I? by the above method and is considered safely shutcown by Maine Yankee.
Fowever, to recuce the reactor coolant temperature to cold shutcown as defined in the plant Techracal Specifications, an acditionel heat removal method is required.
This is provided by the Resicual Feat Removal System, Primary or Secencary Component Cooling water Systems, and Service water System.
_ _. _. - _ _ _ _ _ _ _ _ _, _ _ _ _.. ~. _ _ _. _. _. _, _
Enclosure A Nge 8 of 18 Since these monorails are special purpose and only used on a rare basis, it is not consicered credible that a load drop in the aux 11ary feedwater pump roca could prevent a safe shutccan.
No further analysis of these monorails is considered necessary.
E.
PAB Holst for Uccer Floors (CR-12, MR-12)
The critical volume associated with this hoist is very small and located in the scutheast corner of the building.
It cccurs in an area above the charging punp power cables and the charging pump lube oil pump power caoles approximately 8'8" frem the east wall of the building.
The monorail intersects the routing of the cables at a 900 angle.
The charging pump power cables are routed through steel conduit emcedded in 9" of concrete, as previously stated.
They are also afforded the additional protection provided by the concrete slab forming the floor at the 36' elevaticn. Since loads would only be traveling through the critical volume for a short period of time e no due to the protection provided it is not considereo credible that a load drop from this hoist could result in loss of the ability to borate the reactor plant.
The charging pump lube oil pump pcwer cables are routed in caole trays beneath the 36' elevation and thus could conceivably be incapacitated by a load drcp.
The pump manufacturer, however, has verified that the main charging pumps can be operated without their lube oil pumps. Ring oiling of the bearings is provided, which will adec;uately lubricate the bearings without the luce oil pumps.
This reinforces the assertion that a load drop from this overhead handling system cannot destroy the acility to bcrate.
The west end of this monorai' in the Fuel Building penetrates a critical volume associated with the spent fuel pool coollrg pum? power cables.
This is discussed in conjunction with the Fuel Building Crane in sub-paragraph G.
No further analysis of the PAB hoist for upper floors is considered necessary.
F.
Trolley for Circulating Water Pumo House (MR-6)
The critical volume in the Circulating Water Pump House is associatea with the service water pumps, including piping and power cables.
The service water pumps are spaced 17' apart.
Their power cables are reutea through conduit along the east wall of the service water pump cay.
Sufficient horizontal separation exists such that no load droo can impact on the pcwer cables.
The trolley for the Circulating water Pump House runs parallel to the discharge header piping between the service water pumps and their disenarge valve.
A lead drop cculo conceivably impact en one of the service water pumps or its asscciated discharge valve and piping.
The design of the service water system insures operability following a single piping failure.
Normally, the system is operated with the pump cischarre cross-cennect closed ano the neat exchang r sucply cross-connect open so that a rupture in either the north
Enclosure A
' age 9 of 18 or scuth header will not seriously affect plant operation.
One header is sufficient to meet system requirements and check valves in the supply headers prevent backflow through the ruptured header.
Alternative methcds exist to fulfill the cecay heat removal function of the Service Water System to permit cooldown to cold shutdown.
As discussed previcusly, the Residual Heat Removal System heat exchangers, one Resicual Heat Remcval System pump, and the diesel driven fire pump could be used since they would remain undamaged if a load crop occurred within the Circulating Water FUmp House.
Hose connections are availaole ca the shell sice of both heat exchangers which permit fire pond water to be used to remove heat. Less than 400 gpm per heat exchanger would be required.
This flow rate can be continued for at least 2 months using the minimum amount of available water from the fire pond and the Montsweag Brock Reservoir.
This cooldown path assures the ability to cool to a cold shutdown conoition with Reactor Coolant System temperature well below the Technical Specifications requirement of
~
21C ?.
Repair meadures to restore a damaged Service Water System coulo be completed in this time frame.
Following the necessary repair measures, the Service Water, Primary / Secondary Component Cooling Water / Residual Heat Removal heat removal path would be restored.
Since this monorail is used for a specific purpose and then only rarely and ccasidering the redundant trains available to achieve safe shutdown, it is not considered credible that a load drop from this monorail could prevent a safe shutcown.
No further analysis in this area is consicered racessary.
G.
Monorails for Steam and Feed Valve House lhese monorails are located on top of the Steam and Feed Valve Fcuse.
The critical volume associated with these monorails is that area above the main steam piping up to the non-return valves including the steam line to the cecay heat release valve and the turbine driven auxiliary feed pump.
These menorails are special purpose in that they are only used to perform maintenance on the non-return valves.
This portion of the Main Steam System is necessary for oecay heat removal whicn would be accomplished by venting steem to the atmospnere l
thrcugh the steam generator safety valves and the e:mospneric steam cump I
valve.
If this evolution were in progress, no overhead handling systems capable of operating in the critical volume would be in use.
Conversely, portable hoists would only be utilized after the Primary System had been cooled down with the Residual Heat Removal System removing decay heat.
Inspection of this critical volume also identified several other beams inside the Steam and Feed Valve House to wnicn hoists could be attachec for performing maintenance on other large steam valves within the enclosure.
Enclosure A c ge 10 of 18 a
Maine Yankee can foresee no circumstances when overhead weight handling systems within the critical volume would be in use such that a lead drop could prevent safe shutdown or the acility to remove decay heat.
No further analysis of this area is considered necessary.
H.
Fuel Buildinq Crane (04-6)
The critical volume associated with the Fuel Bruilding Crane contains an area of the spent fuel pool and the Spent Fuel Pool Cooling System.
The systems in the decay heat removal chain for the spent fuel pool incluce the Spent Fuel Pool Cooling System, Primary Component Cooling System, and the Service Water System.
The Primary Component Cooling System and the Service Water Systems were discussed previously.
The power caoles for the spent fuel pool cooling pumps and the purification pump are routed through the cable tray room, the cable vault, through a duct into the PA8 11' level, up a riser along the east wall, then along the north wall into the Fuel Building.
The cables to the cooling pumps are routed through conduit 13'6" from the east wall of the Fuel Building to the cooling pumps.
The purification pump is powered from switchboard MCC-llB in the southwest corner of the truck unloading area of the Fuel Building.
Cables are routeo through a tray in the RCA storage area and then via conduit to the pump.
Critical volumes exist over each of the cable runs.
The critical volume for this system in the Primary Auxiliary Building is not penetrated at any point by the monorail in i
this area.
Normally one of two pumps is run to remove decay heat from the pool.
The purification pump is capable of fulfilling the cooling function for the pool provided the heat load is low, and is available as a backup to the two cooling pumps. Within the Fuel Building, the power cables are routed with sufficienc separation such that a load drop could not damage the power cables to al3 three pumps.
l The pumps themselves, along with the heat exchanger and most of the piping, are located at the 21' level in the Fuel Building.
They are enclosed in a small area of the building north of the spent fuel pool.
There are no overhead weignt handling systems directly over the pumps or heat exchanger.
The Fuel Building Crane is capable of traveling over this area, however, sufficient pnysical separation exists sucn that major system components are not susceptible to camage f cm a load orcp.
The enclosure is bounded by 24" and lo" concrete sicewalls supporting a 15" concrete floor at the 31' 1-1/2" level.
Additionally a 12" concrete ficor around the new fuel storage area exists at t.te 44'5" level.
This concrete floor supports the new fuel storage rack matrix wnich is partially over the fuel pool ecoling components.
Normally this crane is used for unloading new fuel storage Containers and transporting the new fuel assemblies to the new fuel storage area and also to the spent fuel pool.
Unloading new fuel shipping containers is performed under strict administrative controls and the procedure
Enclosure A o ge 11 of 18 a
specifies all storage areas, none of which requires movement over the fuel pool cooling components. Other types of loaos are generally not handled over this area and consist mainly of testing equipment used during refueling operaticns (ie, CEA profilcmetry).
C*.nerally these loads are of insufficient mass to present any oanger to other components in this area.
The power cables for the cooling pumps run from north to south along the underside of a steel girder supporting the mezzanine level approximatelv 13'6" from the east wall of the Fuel Building. Both MR-12 the 71/2 ton upper level Primary Auxiliary Building overhead handling system and tne 5 ton Fuel Building Crane are capable of operating within the critical volume above these power cables.
Monorail MR-12 extends into the Fuel Building ending above the mezzanine level directly over the power cables to the fuel pool cooling pumps.
The current arrangement prevents lowering a load down to the lower level onto a vehicle for transport.
All loads removed from the PAS for transport are handled at the other end of the monorail.
No loads are currently moved from the Primary Auxiliary Building to the Fuel Building with this monorai.l.
This monorail presents no e nger to the power cables of interest.
No further analysis of this incnorail in the Fuel Building is considered necessary.
The Fuel Building Crane could conceivably drop a load within the critical volume in this area.
The power cabling for the purification pump runs along the north and west walls of the building. With the i
exception of a few feet from the west wall to MCC-119, the cabling is outside of the hook travel limits for this crane. Maine Yankee does not foresee any instance where the handling of a load in this area with the Fuel Building Crane could increase the chances for damage to critical components required for dscay heat removal.
Although highly unlikely, if a load drop did result in damage to the cables for the cooling pumps, the purification pump whose cables would not be affected would provide cooling flow until the new power cables l
could be run to the cooling pumps.
Conservative estimates show that these cables could be run in about 8 nours.
An alternative means also l
cxists to provice emergency cooling to the heat exchanger thrcugn l
flanged connections on the cooling water supply and return lines frcm j
the Fire Protection System in the event component cooling water flow was lost.
Detailed engineering inspection of tne critical volumes associated with the Fuel Building Crane have indicated that it is not credible that a load d cp could camage the Fuel Pool Cooling System such that Maine Yankee would be incapable of removing decay heat.
No further analysis of this crane is considered necessary.
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1 Enclosure A Nge 12 of 18 I.
Containment Mnulus Manual Holst (CR-19)
This overnead hanoling system is located at tne 57'10" level in the containment annulus 4'6" " rom the polar crane wall.
It provides 1800 coverage of the annulus from a point even with the pressurizer along the south side of the containment to a point even with steam generator E-1-3.
All piping systems entering the containment are routed through the annulus below the 20' elevation.
All piping enters the loop areas at levels ranging from elevation 6' to elevation 16'.
The systems required for safe shutdown or decay heat removal in this area are: Chemical and Volume Control, Safety Injection, Res!. dual Heat Removal.
The specific lines of concern are the two (2) - 3" enarging lines ~to loops two and three for borati:.n, the 14" residual heat removal suction line from loop 2 hot leg; and the three (3) - 10" HPSI lines into each of the three loops used for residual heat removal return for core cooling.
The three (3) - 10" safety injection header lines enter the containment from the Spray Pump Building through different horizontally separated penetrations.
They are routed next to the outer perimeter of the polar l
crane wall to each of the three loops.
The critical volumes associated with this piping is directly above the area where they travel from the i
containment outer wall to the polar crane sall.
The 3" charging inlet line enters the containment between the loop two safety injection tank and the pressurizer.
The critical volume exists where it crosses the outer annulus.
After going through the regenerative heat exchanger the charging line splits into two headers and travels back through the polar crane wall and runs alongsida the polar crane wall to loops two and three.
The 14" residual heat removal line comes off loop 2 and is routed thrcugh the annulus and into the Spray Pump Building.
The only areas of concern would be associated with where tne piping runs from the Spray Pump Building to the po! ' crane wall.
There are five horizontally separated points wnere the above mentioned piping intersects with the overhead weight handling system (MR-19).
A critical volume exists above each of these points.
The piping runs alongside the polar crane wall are outside of the critical volumi*.
Even though theoretical crit'. 41 vlumes exist, this monorail is incapasle of operating within the spaces just aoove tne critics components.
The crane is located at tne ;7'10" level.
Two floors provice physical separation and protection for the systems required for safe shutdown or decay heat removal.
Tne floor at tnst 46' level is ccmprised of steel grating supported by steel gircers.
The floor at the 20' level is reinforced co srete 24" thick.
The largest load icentified for this monorail is a ::;4ctor heaa stud detensioner wnich weigns sligntly over one ton.
The monorail is mainly used for moving the CECM air ventilation ducting to a storage location in the outer annulus and for moving various tools and components used curing refueling.
This monorail is not used during power operation.
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Enclosure A c ge 13 of 18 a
Cetailed engineering inspection indicates that because of the infrequent use of this overheac handling system and the relatively small loads, the floor at the 46' and 20' levels provide sufficient protection for the critical components.
It is not consicered credible that a load drop from MR-19 could damage a critical system such that safe shutdown or decay heat removal could not be ccmpleted.
No further analysis of this monorail is considered necessary.
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Enclosure A Mge la of 18 2.1.3 WITH RESPECT TO TM DESIGN AND OPERATION OF MAVY-LOAD HANDLING SYSTEMS IN THE CONTAINMENT AND THE SPENT FUEL POOL AREA AND THOSE LOAD HAtOLING SYSTEMS IDENTIFIED IN 2.1-1, ABOVE, ROVIDE YOLR EVALUATION CONCERNING CCMPLIANCE
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WITH THE GUIDELINES OF NUREG 0612, SECTION 5.1.1.
This section will evaluate the Reactor Containment Polar Crane (CR-1) at Maine Yankee.
The cranes associated with the Spent Fuel Pool area and all other load handling systems identified in 2.1-1, above, were evaluatec in Section 2.1-2 and will not be addressed in the response to this section.
A.
ORAWINGS OR SKETCHES SUFFICIENT TO CLEARLY IDENTIFY TM LOCATION OF SAFE LOAD PATHS, SPENT FUEL, AND SAFETY-RELATED EQUIFNENT.
Critical volumes within the containment exist over each of the loop areas and the area over the reactor vessel itself.
The Polar Crane is generally required to operate within these critical volumes. Safe load paths to approved storage areas are administratively controlled and depicted in Maine Yankee Maintenance Procedures. Maine Yankee does not have drawings identifying safe load paths cther than those utilized as part of specific procedures.
Procedures are available for review at the plant site.
B.
A DISCUSSION OF MEASLRES TAKEN TO ENSURE THAT LOAD-HANDLING OPERATIONS REMAIN WITHIN SAFE LOAD PATHS, INCLUDING MOCEDURES, IF ANY, FOR DEVIATION FROM TMSE PATHS.
Maine Yankee defines safe load travel paths through procedures and operator training so that, to the extent practical heavy loads avoid being carried over or near irradiated fuel.
The reactor vessel head storage stand is located outside the refueling cavity between loops two and theee. No safety related equipment is located beneath the travel path. Other large core components are strictly controlled in that their travel paths are specified by a polar crane coordinate system. For those heavy loads handled on a frequent basis (every outage) precedures exist to adequately control movement of heavy loads. Maine Yankee relies heavily on specific procedures and operator training and safety awareness to ensure that all loads are handled in as safe a manner as is l
l feasible. Deviations froin normal load handling would ce accomplished using special precedures approved by the Plant Operations Review Committee.
C.
A TABULATION OF MAVY LOADS TO BE HANDLED BY EACH CRANE WHICH INCLUDES THE LOAD IDENTIFICATION, LOAD WEIGHT, ITS DESIGNATED LIFTING CEVICE, AND l
VERIFICATION THAT TM HANDLING OF SUCH LOAD IS COVERNED BY A WRITTEN l
ROCEDLEE CONTAINING AS A MINIMLN, ThE INFORMATION IDENTIFIED IN NUREG I
0612, SECTION 5.1.1.(2),
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Enclosure A
3ge 15 of 18 The heavy loads (including weights and lifting fixtures) handled routinely by the Polar Crane curing outage conditions are as follows:
APfROXIMATE DESIGNATED COMPONENT WEIGHT LIFTING FIXTURE a.
Reactor Vessel Closure head /250,000 lbs/ Head lifting fixture.
b.
Upper Guide Structure
/ 94,500 lbs/ Reactor internals lifting fixture.
c.
CEDM Missile Shield
/ 88,000 lbs/ Aporopriately sized 6 x l? Preforced, Improved Plow Steel IWRC bridle sling.
d.
Reactor Water Cavity Seal
/ 18,000 lbs/ #ppropriately sized 6 x Ring 19 preformed, Improved Plow Steel IWRC caole slings.
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e.
Stud Tensioners
/ 2,250 lbs/ Appropriately sized 6 x 19 Preformed, Improved Plow Steel IWRC cable sling.
Maine Yankee uses detailed procedures which substantively meet the requirements identified in NUREG 0612, Section 5.1.l(2).
These procedures identify required equipment; inspections and acceptance criteria required before movement of load; detailed steps and prcper sequence to be followed in handling the load and the safe load path.
A separate procedure is not considered necessary for the stud tensioners.
l Their movement is covered in procecures for removing reactor vessel head closure studs.
Maine Yankee also has procedures to handle the following loads not l
routinely lifted during every cutage:
APFROXIMATE DESIGNATED t
CCMFONENT WEIGHT LIFTING FIXTURE a.
Core Support Barrel
/269,000 lbs/ Reactor internals Assemoly lifting fixture.
b.
Core Support Barrel
/ 80,000 lbs/ Appropriately sized 6 x Radiation Shield 19 Preformeo, Tmproved i
Plow Steel IWRC caole l
slings.
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Enciccure A 7 ' age 16 of 18 APR OXIMATE DESIGNATED
_ EIGHT LIFTING FIXTURE COMPONENT W
c.
Reactor Coolant Pump Motor
/123,000 lbs/ Appropriacely sized 6 x 19 Preformec, Improved Plow Steel cable slings.
d.
Reactor Coolant Pump Driver / 36,000 lbs/ Appropriately sized 6 x Mount and Rotating Assemoly 19 Preformed, Improved Plow Steel caule slings.
The closure head stud storage rack and studs (approximately 11 tons) has been identified as a heavy load which is not directly covered in current Maine Yankee procedures.
Adequate controls to cover the movement of this lead will be incorporated into existing procedures prior to 1982 refueling cutage.
O.
VERIFICATION THAT LIFTING DEVICES IDENTIFIED IN 2.1.3-c, ABOVE, COMPLY WITH THE REQJIREMENTS OF ANSI N14.6-1978, OR ANSI B30.9-1971 AS APROFRIATE.
FCR LIFTING DEVICES W ERE TESE STANDARDS, AS SUPPLEMENTED BY MJREG 0612, SECTION 5.1.l(4) or 5.1.l(5), ME NOT MET, DESCRIBE ANY RCPOSED ALTERNATIW.S AND DEMONSTRATE TEIR EQUIV4 ENCY IN TERMS OF LOAD-HAM) LING RELIABILITY.
Two special lifting devices were identified in 2.1.3-c above: reactor vessel closure head lifting fixture and the reactor internals lifting fixture.
NUREG 0612 states that special lifting devices should satisfy the guidelines of ANSI N14.6-1978, " Standard for Special Lifting Devices for Shipping Containers Weigning 10,000 Pounds (4500 Kg) or More for Nuclear Materials". Maine Yankee does not consider that this standard As applicable for special lifting devices for the closure head and upper guide structure.
Shipping containers are handled frequently whereas the closure head and upper guide structure are handled only twice every outage. With cutages occurring at 12-14 mcnth intervals, these lifting devices may see a total of from 70-80 lifts assuming a forty year plant life.
All lifts are strictly controlled through precedures and conducted by trained operators.
These two special lifting devices were provided by Maine Yankee's NSSS supplier - Comoustien Engineering (C-E).
The closure head lifting rig was provided in a package with the closure head and vessel. We are in the process of obtaining the specific design and testing cata from C-E for Maine Yankee analysis and review.
The reactor internals lifting rig is designed to lift the core support barrel assemoly consisting of the core carrel, thermal snield, core shrouds and instrumentation support structure.
The operating load of 7
this assemoly is 269,CCO lbs.
The lifting rig has been tested to 125%
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of the operating load.
The actual proof load lift was approximately 351,000 lbs.
Normally, this lifting fixture is used twice every cutage to lift the upper guide structure wnich weighs approximately 94,500 lbs.
The core support barrel assembly is handled only for 10 year
Enclosure A
' age 17 of 18 reactor vessel inservice inspections.
For this lift, the fuel assemolies will have been removed and transferred to the spent fuel pool thus removing the danger of a radioactive release which could potentially produce doses exceeding 10 CFR Part 100 limits.
These two lifting devices were designed prior to ANSI N14.6-1978 and are not required to comply with the specifics of this stancard. Maine Yankee is reviewing the documentation for each of these lifting devites to determine what actions, if any, are required to improve load-handling reliability.
This review will be completed prior to the 1982 refueling outage Maine Yankee utilizes a specific maintenance procedure which governs and documents the, sling inspection program.
Each sling has a specific identification tag and is required to be inspected on a yearly basis.
This inspection program meets the requirements of ANSI B30.9-1971.
Each individual procedure for lifting heavy loads is being checked for compliance with this ANSI stancard.
E.
VERIFICATION THAT ANSI B30.2-1976, CHAPTER 2-2, HAS BEEN INVOKED WITH RESPECT TO GANE INSPECTION, TESTING AND MAINTENANCE. WFERE ANY EXCEPTION IS TfEEN TO THIS STANOMD, SUFFICIENT INFORMATION SHOULD BE
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PROVIDED TO DEMONSTRATE THE EQUIVALENCY OF FROFOSED ALTERNATIVES.
Maine Yankee has specific maintenance procedures governing periodic inspection and maintenance of all major cranes at the site.
The reactor containment polar crane receives an intensive inspection by a whiting Crane representative prior to each cutage. Deficiencies identifieo are corrected prior to crane use and documented in the material history l
folder. Specific inspections required on a daily basis are covered in specific procedures or through operator training and are generally performed each shift. Maine Yankee considers that this program meets the intent of ANSI B30.2 - 1976, although this standard does not apply to Maine Yankee's cranes as discussed in the response to F below.
F.
VERIFICATION THAT CRANE DESIGN COMPLIES WITH TFE GUIDELINES OF GAA S ECIFICATION 70 AND CHAPTER 2-1 0F ANSI B30.2-1976, INCLUDING THE DEMONSTRATION OF EQUIVALENCY OF ACTUAL DESIGN REQUIREMENTS FOR INSTANCES WHERE SPECIFIC CCMPLIANCE WITH THESE STANDAROS IS NOT FROVIDED.
The Maine Yankee polar crane was procured prior to publication of CMAA
- 70 and ANSI B30.2-1976 and is designed in accordance witn tne Electric Overhead Crane Institute (EOCI) specification #61.
The polar crane l
generally meets the design requirements as set forth in ANSI B30.2-1976 l
and CMAA #70 althougn some design terminology of EOCI #61 differs from i
that of OdAA #70. For example, the allowable cesign stresses for the bridge girder are slightly lower for EOCI #61 than they are for CMAA l
- 70.
However, due to the plant locaticn the Maine Yankee polar crane nas designed so that rcutine lifts could be safely hancied with temperatures of crane parts as low as -200F with icing conditions prevailing prior to containment ccmpletion.
All heavy and overload l
lifts have been made after containment enclosure with temperatures not i
l less than 30cF.
I Enclosure A
' age 18 of 18 Maine Yankee believes that it would be inappropriate to require that cranes installed over ten years ago comply with new standards.
The older cranes were designeo in accordance with the standards available at that time and are adequately engineered and tested to handle the required loads.
G.
EXCEPTIONS, IF ANY, TAKEN TO ANSI B30.2-1976 WITH RESPECT TO OPERATOR TRAINING, QJALIFICATION, ANO CONOUCT.
Currently, Maine Yankee procedures and the crane operator training program reference USAS B30.2-1967 as tne applicable standarc.
There is virtually no ciffererx.e between the requirements of the USAS stancard and the ANSI standard. Management actions are currently being undertaken to revise our procedures and training program utiliring ANSI B30.2-1976.
All personnel who operate the polar crane have been trained and tested in accordance with the Maine Yankee training program which satisfies the intent of ANSI B30.2-1976.
Training records documenting this training are stored at the plant site.
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