ML13317A859
| ML13317A859 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/05/1982 |
| From: | Baskin K Southern California Edison Co |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| GL-81-007, REF-GTECI-A-36, REF-GTECI-SF, RTR-NUREG-0612, RTR-NUREG-612, TAC-08082, TAC-8082, TASK-A-36, TASK-OR NUDOCS 8202090240 | |
| Download: ML13317A859 (17) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN TELEPHONE MANAGER OF NUCLEAR ENGINEERING, February 5, 1982 (213) 572-1401 SAFETY, AND LICENSING Director, Office of Nuclear Reactor Regulation Attention:
D. M. Crutchfield, Chief Operating Reactors Branch No.
5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Control of Heavy Loads NUREG-0612 San Onofre Nuclear Generating Station Unit 1
References:
- 1. Letter, D. G. Eisenhut, NRC, to All Licensees, Control of Heavy Loads, December 22, 1980
- 2.
Letter, D. G. Eisenhut, NRC, to All Licensees, Control of Heavy Loads (Generic Letter 81-07), February 3, 1981
- 3. Letter, D. M. Crutchfield, NRC, to R. Dietch, SCE, SEP Topic 111-6, Seismic Design Considerations, San Onofre Unit 1, November 16, 1981
- 4. Letter, K. P. Baskin, SCE, to K. R. Goller, NRC, Additional Information Regarding Spent Fuel Shipping Cask Handling, March 21, 1975 References 1 and 2 requested that we evaluate heavy load handling capabilities at San Onofre Unit 1. Specifically, we were requested to:
- 1. Implement interim actions within 90 days,
- 2. Provide general information within 6 months,
- 3. Provide specific information within 9 months, and
- 4. Implement any necessary modifications, based on 2 and 3 above, within 2 years.
The purpose of this letter is to provide the current status of each of the items discussed above. The organization of the information provided below corresponds to that.discussed above and in References 1 and 2.
8202090240 820205 A
PDR ADOCK 05000206 P
Mr. D. i.
February 5, 1982
- 1.
Implement Interim Actions We have taken steps to. implement the interim actions discussed in References 1 and 2. However, as has been discussed with your staff, these interim actions have not yet been fully implemented. Each of the interim actions from References 1 and 2 are restated below followed by a summary status of the work completed to date and our schedule for completing implementation of the interim actions.
Interim Action (1)
Safe load paths-should be defined per the guidelines of Section 5.1.1(1) of NUREG-0612.
Summary Status
.Based on. a' review of, (1) the. heavy load'hand.ing systems, (2) the loads
'carried by these systems, (3) the procedures for using, these systems, and (4) the location 'of spent fuel and equipment necessary to achieve and maintain the conditions for Residual Heat Removal System (RHRS) operation in relation to th'esesystems', the: on'ly heavy load handling systems which have the potential to drop a load into spent fuel or equipment required to achieve and maintain the conditions for RHRS operation are the reactor service crane, turbine gantry crane and the spent fuel pit bridge crane.
Safe' load paths have been defined for the movement of heavy -loads by each of these cranes as discussed below:
The reactor service crane is used only when the RHRS is operating; therefore, equipment to achieve the conditions for RHRS operation need not be considered. In order to minimize the possibility of a load drop from the reactor service crane interacting with spent fuel or with RHRS equipment,. lifting requirements have been prescribed as follows:
- 1)
With the rea.ctor vessel head installed, lifting will not be permitted over the cabling associated with the RHRS.
Figure 1 shows the restricted load handling areas. The load handling areas not restricted have three to five foot thick reinforced concrete decks which will function as a safe load path and will minimize the potential for heavy loads, if dropped, to impact irradiated fuel in the reactor vessel or to impact safe shutdown equipment.
- 2)
Lifting of the reactor vessel head and the upper internals assembly will be restricted to the load paths shown in' Figure 2.
These load paths have been specified to minimize the consequences of a load drop.
Mr. D.
February 5, 1982
- 3) With the reactor vessel head removed and fuel in the vessel, lifting over the open reactor vessel will be restricted.to the reactor vessel.head, the upper internals assembly and the Inservice Inspection (ISI) tool and will not be permitted over the cabling associated with' the RHRS.
Figure 3 shows the restricted load handing areas. The lifting limitations specify restricted areas as discussed in 1 above.
The turbine gantry crane can'be used under any operating condition., but until such time, the upgrades to the North. Turbine Building and West Heater Platform identified in the SER issued by Reference 3 are completed, the.turbine gantry.crane. will be parked'at the extreme' south l'imit-of travel, or the'reattor is to be shutdown -during periods when crane movement is required..The lifts by this. crane can be grouped into four categories:
(1) turbine generator maintenance lifting, (2) new fuel shipping container lifts,.(3) spent fuel cask handling, and
.'(4) miscellaneous lifting.<.Turbine generator maintenance lifts (i.e.,
covers, rotors, etc..).are performed only when the.RHRS is operating.
Under these conditions, load handling operations over the turbine deck south 'of the high pressure turbine are not. of concern because no RHRS equipment or cabling is located there. -New fuel handling and spent fuel cask handling might be performed when the RHRS is operating or when the plant is in operation.
Spent fuel cask drops over the turbine deck have been thoroughly analyzed (Reference 4) and those -analyses have been reviewed and approved by the NRC which resulted in the establishment of load paths for the handling.of.the spent fuel cask. Miscellaneous lifts might be performed when the RHRS is operating or.when.the plant is in operation. Since the areas under the turbine deck' between the containment sphere and the high.pressure turbine.(i.e., the north turbine deck extension) contains many piping and cabling runs associated with systems required to achieve-and maintain the conditions for -RHRS operation, miscellaneous lifting will be permitted over.the north turbine deck extension, following, to the extent practical, structural floor members, beams, etc., such that if the load is dropped,.the structure is more likely to withstand the impact.
Figure 4 shows the safe load path handling area and Figure 5 shows the location of structural floor members and beams.
There is only one load lifted by the spent fuel pit bridge crane of concern; namely, the gate separating the transfer mechanism area from the spent fuel area. This-lift is normally made twice per..refueling outage.
The existing Technical Specification which prohibits movi-ng heavy loads over the spent fuel racks provides a suitable basis for meeting the intent.of NUREG-0612 requirements.
The load paths and restricted areas discussed above will be implemented by operating memorandum' by February 22, '1982, and thereafter, deviations will only be made with' the written approval of the plant safety review committee. The cranes discussed aboveare not expected to be utilized prior to the implementation of the load paths and restricted areas.
Mr. D.
February 5, 1982 Interim Action (2)
Procedures should be developed and implemented in accordance with the guidelines of Section 5.1.1(2) of NUREG-0612.
Summary Status The lifting limitations for the reactor service crane with the reactor vessel head installed and with the reactor Vessel head removed and fuel in the vessel have been defined in a draft operating procedure. The load paths for the reactor service crane during lifting of the reactor vessel head and the upper interhals have been defined in.
draft changes to each edition of the special procedure for refueling.
The lifting limitations for the turbine gantry crane have been defined in a draft operating procedure provided.
In addition, the inspection of equipment during spent fuel cask handling and receipt and handling of new fuel has been defined in draft'revisions to procedures.
The draft procedures and draft revisions to procedures discussed above are currently being reviewed. We will advise you by February 22, 1982 concerning the schedule for implementation-of the approved procedures.
In the interim, until these procedures are implemented, the load paths and restricted areas established in accordance with Interim Action (1) will remain in effect. Following implementation of the procedures, deviations from the procedures will only be made using written alternative procedures approved by the plant safety review committee.
Interim.Action (3)
Crane operators should be traihed, qualified and conduct themselves per the guidelines of Section 5.1.1(3) of NUREG-0612.
Summary Status The crane operation and rigging training programs at San Onofre Unit 1 satisfy the intent of ANSI B30.2 and NUREG-0612 but differ administratively.
These administrative changes have. been drafted and are currently being reviewed. We will advise you by.February 22, 1982 concerning the schedule for implementation of the approved changes. In.
the interim, until these changes are implemented, the existing programs satisfy the intent of ANSI B30.2 and -NUREG-0612.
Interim Action (4)
Cranes should be inspected, tested,-and maintained in accordance with guidelines of Section 5.1.1(6) of NUREG-0612.
Mr. D. M..Crutchfield February 5,"1982 Summary Status The current maintenance and inspection program for cranes comes close to satisfying the inspection, testing, and maintenance requirements of Chapter 2-2 of ANSI B30.2-1976 "Overhead and Gantry Cranes."
To fully satisfy these requirements, draft revisions to the program have been prepared and are currently.being.reviewed. We will advise you by February 22, 1982 of the schedule for implementation of the approved revisions.
In the interim until these revisions are implemented, the
.existing program comes close.to satisfying.the inspection, testing and maintenance requirements of Chapter 2-2 of ANSI B30.2-1976.
However, the test requirements contained in ANSI B30.2-1976 will not be met. The standard requires full traverse of both the bridge/.gantry and the trolley with a rated load to test the bridge/gantry rails and spanning guides. Evidence presented in NUREG-0612 suggests that, historically, failures of -the bridge/gantry',rails or spanning guides are unlikely. In addition, heavy loads are not usually handled to all extremes of -position. Therefore, more plant equipment would be exposed to.potential heavy load drops by the'test than would be expected during normal crane operation..
In addition, the turbine gantry crane is not.tested to 125% of rated load.
The crane was or.iginally"rated at '115 tons but was adjusted to 100 tons when the crane ma'ufacturer did-not recommend testing above 125 tons. The crane is currently certified by the State of California by lifting the heaviest load it faces--the generator rotor, which weighs 108 tons. Heavy loads of more than 30.tons: are. not lifted unless the RHRS is operating. The 30.ton spent fuel cask is the heaviest load handled during normal operation.
Interim Position (5)
In addition to the above, special attention should be given to procedure, equipment, and personnel for the'handling of heavy' loads over the core, such as vessel internal.s or vessel inspection tools. The special review should include the following for these loads:
- 1) review of procedures for installation of rigging or lifting devices and movement of the load to assure that 'sufficient detail is provided and the instructions are clear and concise;
- 2) visual inspections of load bearing components.of cranes, slings, and special lifing devices to identify flaws or deficiencies that could lead to failure of the component;
- 3) appropriate repair and replacement of defective components; and
- 4) verify that the crane operators have been properly trained and are familiar with specific procedures used in handling these loads, e.g., hand signals, conduct of operations, and content of procedures.
Mr. D.
February 5, 1982 Summary Status Three lifts are routinely scheduled over the open reactor vessel when fuel is in the vessel:
(1) the reactor vessel head, (2) the upper internals assembly, and (3) the reactor vessel ISI tool.
Each of the four areas of concern raised in Interim Action (5) are addressed below:
- 1) A.draft operating procedure for the reactor service crane and draft changes to each edition of the special procedure for refueling have been prepared and are currently being reviewed. The information contained therein addresses the installation of rigging or lifting devices and movement of the load to assure that sufficient detail is provided and the instructions are clear.and concise.
- 2) Draft revisions to the maintenance and inspection program for cranes have been prepared and are currently being reviewed.
The information contained therein includes visual inspection of load bearing components of cranes, slings, and special lifting devices to identify flaws or deficiencies that could lead to failure of. the component.
- 3) Draft revisions to the maintenance and inspection program for cranes have been proposed and are currently being reviewed.
The information contained therein addresses repair and replacement of defective components.
- 4) Draft administrative changes to the crane operation and.rigging training programs at SanOnofre-.Unit 1 have been prepared and are currently-being reviewed. The.-information contained therein assures that crane operators are properly trained 'and are familiar with specific procedures used in handling heavy loads.
- 2.
Provide General Information It is.currently anticipated that the general information report will be submitted by April 1, 1982.
- 3.
Provide Specific Information It is currently anticipated that the specific information report will be submitted by May 1, 1982.
- 4.
Implement Necessary Modifications
'Since the exact nature of any procedural changes or equipment modifications is not known at this time, we consider i-t inappropriate to commit to implement such.changes or modifications within two years, other
Mr. D.
February 5, 1982 than those necessary to implement the interim actions. -Implementation schedules will be established at the time any procedural changes or equipment modifications are identified.
If you have any questions or desire further information concerning our plans discussed above, please contact me.
Very truly yours, Enclosures
FIGURE 1
EQUIPMENT RESTRICTED REMOVAL MATCH
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FIGURE 2
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FIGURE 3
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FIGURE 4
TAKE-am CONTROL TOWER AND ADMINISTRATION ELT 35JE OOE NETW S C UAUX TOANSO ATA GENRAOR SOU?1 It INE OENERATDCK EXTENSION EEL.
42 17 S31PAPEj TAR TANK OFFANW 100 (PACATRKECSMI L 3PLANT NORTH 0
or BUILDING TURBINE GANTRY CRANE SERVICE AREA
FIGURE 5
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