05000306/LER-1997-001-01, :on 970207,heavy Load Transported Over Irradiated Fuel or Safe SD Equipment W/O Establishing Required Conditions.Caused by Failure to Follow D58.Movement of 22 RCP Placed on Hold Until Procedures Revised
| ML20147F485 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 03/17/1997 |
| From: | Leveille J NORTHERN STATES POWER CO. |
| To: | |
| Shared Package | |
| ML20147F462 | List:
|
| References | |
| LER-97-001-01, LER-97-1-1, NUDOCS 9703250236 | |
| Download: ML20147F485 (18) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition |
| 3061997001R01 - NRC Website | |
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NRC FORM 366 U.S. NUCLEAR R GULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 M 95)
EXPIRES 04/30/S8 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMAtl0N COLLECTION REQUEST: 50.0 HRS. REPORTED LESSONS LE ARNED ARE INCORPORATED IN LICENSEE EVENT REPORT (LER)
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FAi1LITI RAKE (A)
Dwa s 4 pausas idl FA4iB (3J Prairie Island Nuclear Generating Plant Unit 2 05000 306 1 oF 18 T4TbE i43 Transporting a Heavy Load over Irradiated Fuel or Safe Shutdown Equipment without Establishing the Required Conditions EYul LATE (5)
LER NUMBER (6)
KEFORT LATE (7)
OIn&M FACILITIES INVOLVED (8)
MJNIH DAT YLAR YLAH blUULNilAL fitVl51UN MUNIH DAY YEAH FACIL4TY NAME Lotu,1 NUMBER NWBR WMBm Prairie Island Unit 1 05000 282 02 07 97 97 -- 01 --
00 3
17 97 FACILITY NAME DOCKET NUMBER 05000 1
OFERAIING THIS EEFORT 15 EUDMATTw FRiSUANT TO THE EEQUI.sEMENT5 OF 10 CFR 5 (Clieck one or more)
(11) j MODE m N
20.2201(b) 20.2203(a)(2)(v) bo.73(a)(2)(i) 50.73(a)(2)(viii)
FOwsR 20.2203(a)(1) 20.2203(a)(3)(i)
X 50.73(a)(2)(ii) 50.73(a)(2)(x)
LEVEL (10) 0 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 60.73(a)(2)(in) 73.71 20.2203(a)(2)(li) 20.2203(a)(4) 50.73(a)(2)(iv) oTHER 20.2203(a)(2)(m) 50.36(c)(1) 60.73(a)(2)(v) gn stra below or i "
70.2203(a)(2)(IV) 50.36(C)(2) 60.73(a)(2)(vu)
LICENs 3 CONTACT FOR THIS LER (14) wAms ui.u nus,a mm.u ;InC 4 Wf Alee LOMJ Jack Leveille 612-388-1121 COMFLETE ONE LIUE FOR EACH COMFUNhNT FAILVRE LE5C(IEED IN THIS EEFORT (13)
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ABbTRACT (Limit to 1400 spaces, i.e.,
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(10)
On 2/4/97, it was determined that 22 Reactor Coolant Pump upper bracket and rotor (heavy load - 21 tons) was moved over irradiated fuel on 2/3/97, without a specific load handling procedure defining the safa load path and without containment isolated. The movement of this heavy load in containment did not follow the reactor building safe load path requirements stated in Ope itions Manual Section D58, Control of Heavy Loads. D58 states that "With the reactor head remove, loads greater than 2100 lb.
SHALL NOT be moved within 15 horizontal feet of the irradiated fuel without specific written procedures per step 5.3.5" and containment isolation requirements satisfied. Neither of these provisions were satisfied. Following this event two subsequent heavy load lifts were recognized as not mrting the intent to control heavy load lifts where safe shutdown equipment could be affected.
Corrective actions, taken and planned, address issues raised by this event. These issues include:
procedure compliance, adequacy of the heavy loads program, human factors considerations of the implementing procedures, and training and qualifications of the individuals with responsibilities for implementation of the program features.
9703250236 970317 PDR ADOCK 05000306 S
PDR NRC FORM 76614 prq
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-(CHRONOLOGICAL DESCRIPTION)
First Heavy Load Lift 9/4/96 W0 9608888, D15.2; 10 year RCP Motor Inspection, prepared with procedure D15.2, Reactor Coolant Pump Motor Cleaning Procedure.
12/19/96 D5S, Rev. 25 - Control of Heavy Loads, reviewed by Operations Committee and approved for use.
Revision 25 added requirements for moving loads over Spent Fuel Pool' (SFP) enclosure as a result of a review of the heavy loads program per NRC Bulletin 96-02," Movement of Heavy Loads j
over Spent Fuel Pool, Over Fuel in the Vessel,..." This revision also revised the turbine laydown j
area for smaller low pressure turbine rotor stands.
]
12/20/96 Read and sign training exercise on the Rev. 25 changes to D58 sent to the Engineering and Tech l
Staff (E&TS) by computer.
l 1/21/97 Maintenance riggers and repairman received training on Rev. 25 changes to D58. This training did not include the entire procedure, only the Rev. 25 revisions made for moving loads over the SFP enclosure. Traveling maintenance personnel (travelers) assigned to PI for the upcoming outage were also included in this training session.
1/27/97 WO 9608888, D15.2; 10 Year RCP Motor Inspection, isolated per D15.2 and given Shift Supervisor (SS) Approval to Start Work (ASW).
Maintenance personnel started work on 22 RCP motor per D15.2. Work on 22 RCP progressed over the next week until the section of the procedure for removing the upper bracket and rotor was reached.
'(Ells System identifier: BP; Ells Component identifier: PSP)
'(Ells System identifier: BQ; Ells Component Identifier: PSP) 1
- (Ells System Identifier: CB; Ells Component identifier: PSP)
'(Ells System identifier: ND)
NRC FORM 3GF A14 95)U.S. NUCLEAR REGULATORY COMMISSICd
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g M 951 LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION Prairie Island Nuc ear G ra ing Plant U2 05 0 06 YEAR t
4 F
18 97 -- 01 --
00 TEXT III more space 2s requ1 red, use add 2 C2Onal copses of NRC Form 366A) il7) 2/3/97 The system engineer contacted the day shift maintenance supervisor and made arrangements to have maintenance personnel remove 22 RCP upper bracket and rotor from the stator and move it to the RCP motor stand. The maintenance supervisor assigned the task to the traveling maintenance supervisor and the lead rigger assigned to containment.
Once in containment the system engineer, traveling maintenance supervisor, lead rigger and crane operator briefly discussed what needed to be done and that the control room should be contacted before anything was taken over the refueling pool. No discussion about D58 requirements for moving a heavy load in containment was included.
The lead rigger contacted the control room and informed a SS that they were preparing to remove 22 RCP rotor. This would involve moving the polar crane empty hook over the refueling pool to go pick up the RCP motor lifting fixture. Once this was attached to the hook it would be brought back over the pool and then lowered into 22 RCP vault, After the lifting fixture was in the RCP vault, the lead rigger along with the machinists working on 22 RCP, attached the lifting fixture to the lifting lugs on 22 RCP upper bracket. Once this was done the lead rigger inspected the rigging, load bearing components; shackles, turnbuckles, lifting fixture j
cable clamps and cable. When satisfied that all the lifting equipment and connections were satisfactory, the load was lifted enough so it could be checked for level. The load had to be set back down, adjusted, and then lifted again to check for level. This had to be repeated several times to ensure that load was level so the rotor would not make contact with the motor stator as it was being removed.
Before making the lift the lead rigger contacted the control room again to inform the Unit 2 SS that they were ready to lift 22 RCP rotor out of the vault and move it over the edge of the pool to the motor stand. During this conversation there appears to have been some misunderstanding between the two individuals on what the load path was going to be. The lead rigger thought the SS gave the OK to move the load across the pool. The SS understood that the load would follow a safe load path near the edge of the pool. Neither individual remembered that a heavy load couldn't be moved within 15 horizontal feet of the irradiated fuel without a specific written procedure.
Sometime around 1130,22 RCP motor upper bracket and rotor were lifted from the pump vault and moved to the RCP motor stand. The path taken to the motor stand was as follows (refer to Figure 1): the RCP upper bracket and rotor lifted vertically out of the motor stator and vault until it was above the CRDM piping on the pool side of the vault, the load was then moved horizontally to approximately a third of the way out over the refueling pool, the polar crane bridge' was then
"(Ells Component Identifier: CRN)
NRC FORM 35GA M 95)
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. ~.U.S. NUCLEAR REGULATORY COMM3SS3ON g
j M 9W LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILIrY NAME (1)
DOCKET LER NUMBER (6)
PAGE (3)
Prairie Island Nuclear Generating Plant U2 05000 306 YEAR 5tu L
m 5
OF 18 97 -- 01 --
00 TEXT Ut Diore space as requ1 red, use additional coples of NRC Fonn 366A) (17) rotated to a position that would allow the trolley to move the load to the stand, the load was then moved horizontally across the pool to the RCP motor stand. The RCP motor stand is located on 4
top of the removed pressurizer missile shield sitting on the 755' level of containment near 21 RCP vault. According to the lead rigger the heavy load was within the 15' area of the core for approximately 2 minutes. For a part of this 2 minutes the heavy load crossed over a portion of the core.
1 Maintenance electricians completed inspection, testing and cleaning of 22 RCP rotor per D15.2.
I 2/4/97 22 RCP upper bracket and rotor ready to be moved from the RCP motor stand back to the stator in 22 RCP vault. Maintenance personnel prepare to move the RCP rotor from the stand by attaching i
the motor lifting fixture to the upper bracket.
l l
The lead rigger contacted the control room and informed the Unit 2 SS of the move they were ready to make. During this phone conversation the SS questioned the path the load would be 1
taking and was told it would be over the refueling pool to the pump vault. With fuel handling in progress, going over the refueling pool with a heavy load was a concern to the SS, so he told them
)
to wait until he did some further checking to determine if it was OK The SS discussed this with i
Shift Manager (SM) and it was determined from reviewing D58 that the heavy load move could not i
be made. The lead rigger was told they couldn't make the move witnout an approved procedure, j
The lead rigger informed the system engineer of shift management's decision. The system engineer contacted the SM to find out what was going on and why the rotor couldn't be moved.
When told that a specific procedure was required to move the rotor across the refueling pool, if the load would be coming within 15 feet of the irradiated fuel, he informed the SM that the rotor had been moved across the refueling pool to the motor stand the day before without an approved j
procedure. From this discussion and further review of the D58 requirements for moving a heavy load in containment it was determined that the rotor had been moved within 15 feet of the irradiated fuel on the previous day (2/3/97) in violation of the D58 requirements. D58 was violated by not having an approved written procedure and containment isolated.
The job was placed on hold until further evaluation of the situation could be completed. It later was determined that a specific procedure would have to be written and approved by the Operations Committee (OC) before the RCP upper bracket and rotor could be moved back across the refueling pool to the RCP vault.
2/5/97 WO 9700661 was written to lift and move 22 RCP upper bracket and rotor in accordance with the D58 requirements. The procedure was reviewed and approved by the Operations Committee on tU.S. NUCLEAR REGULATORY CO30GSSION 14-9 5)
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22 RCP upper bracket and rotor were then moved from the RCP motor stand to the motor stator in accordance with this procedure.
2/7/97 1450 - The determination was made that Prairie Island Unit 2 was in a condition outside of the design basis of the plant on 2/3/97 when 22 RCP upper bracket and rotor was moved over the core and the requirements of D58 were not met.
1625 - The plant made a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Non-Emerge.acy notification to the NRC informing them of the event that took place on 2/3/97 that placed Unit 2 in a condition outside the design basis.
Between First and Second Heavy Load Liits The first event was self-identified and short term corrective actions were taken immediately to prevent a similar event from recurring before the long term corrective actions could be implemented. One of the short term corrective actions taken was to communicate to all site personnel about heavy loads to heighten their awareness of the requirements of D58, Control of Heavy Loads. This increased awareness to the movement of heavy loads prompted some personnel to question the heavy load moves they had observed. From this increased awareness the second and third heavy load events were questioned and D58 reviewed to determine if the requirements were followed. For these heavy load moves it was discovered that D58 doesn't specifically address moving a heavy load near safe shutdown equipment or over available equipment using a mobile crane or fork lift.
From the first event investigation it was determined that D58 was difficult to use and would need to be revised. To help maintenance personnel and other site personnel ensure that the requirements of D58 were being applied before moving a heavy load with any of the plants installed cranes, a checklist was developed to ensure that D58 requirements were applied. This checklist did not include mobile cranes because D58 did not include the use of mobile cranes.
2/19197 The cleaning and inspection of 22 CW pump motor under WO 9700434 was completed and the motor was ready to be reinstalled. Also,21 CW pump was prepared to be removed after setting 22 CW pump motor because of the extra precautions and requirements that needed to be satisfied to set up the mobile crane in this area. The system engineer reviewed D58 and found that the procedure did not contain specific requirements pertaining to the use of a mobile crane for moving a heavy load. From this review it was concluded that the requirements in D58 didn't apply to the use of a mobile crane and did not specify a safe load path requirement for heavy loads in the area of the Plant Screenhouse, so no specific procedure was prepared to cover the movement of 22 CW gU.S. NUCLEAR REGULATORY COMMISSION 14 95)
LICENSEE EVENT kEPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
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Prairie Island Nuclear Generating Plant U2 05000 306 YEAR MUU lAL R
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00 TEXT Ut more space as required, use additional cop 1es of NRC Form 366A) (17) pump motor or the removal of 21 CW pump. The WOs did address the use of a mobile crane to lift the heavy load and identified the weight of the loads, but the WOs did not identify a safe load path.
The precautions pertaining to nearby electrical equipment and the load path to follow for avoiding i
safe shutdown equipment in the Screenhouse were verbally addressed at the pre-job briefing.
Back on 1/28/97, when 21 & 22 CW pump motors were removed under WOs 9700434 & 9614599, the system engineer took the same precautions concerning the use of the mobile crane and made sure that the mobile crane operator and riggers understood the load path to be followed. This information was presented to the personnel involved with the load handling operations at the pre-job briefing held prior to the start of the job.
Around 0910, the system engineer held a pre-job briefing with the riggers, mobile crane operator, maintenance supervisor and other personnel who would be reinstalling 22 CW pump motor and then removing 21 CW pump. The briefing included a discussion on where the mobile crane should be set up, where the flat bed truck carrying the pump motor should be parked, the load path for moving the motor from the trailer into the Screenhouse. The location of the mobile crane and flat bed truck were established to prevent accidental contact with nearby electrical equipment. The j
load path described was to stay clear of the center area of the Screenhouse roof which is over the diesel cooling water pumps and to stay clear of the Unit 2 elec+rical transformers and high voltage lines.
The rigging equipment was inspected and attached to the CW pump motor following standard NSP rigging requirements and practices, which meet ANSI and OSHA standards.
The CW pump was lifted from the flat bed trailer and moved into the Screenhouse through an opening in the Screenhouse roof (refer to Figure 2). The pump was lowered to the lower level and set in place. After 22 CW pump motor was set in place,21 CW pump was rigged and removed through the Screenhouse roof opening and placed on the flat bed trailer.
The NRC Resident inspector observed the lift of 22 CW Pump motor and the removal of 21 CW pump and had a concern with the potential impact on safe shutdown equipment in the Screenhouse because of the load paths close proximity to the area of the Screenhouse roof over the safe shutdown equipment. The NRC Resident Inspectors determined that D58 was not adequate in that it did not contain the necessary administrative controls for handling heavy loads over or near safe shutdown equipment when using a mobile crane.
2/21/97 Before reinstalling 21 CW pump a specific procedure, WO 9614600 Attachment 1, was prepared and approved by the Operations Committee to lift and move the Unit 2 Screenhouse hatch cover and to lift and move 21 CW pump from the turbine building to the Screenhouse. This pi'ocedure NRC F03M 366A (4 951
tU.S. NUCLEAR REGULATORY COMMISSION
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(17) defined special considerations and defined a safe load path which avoided identified safe shutdown equipment and the Unit 2 transformers.
Third Heavy Load Lift 2/25/97 System engineer requested maintenance to remove one of the concrete trench covers from the Unit 2 Auxiliary Building trench for ISI of pipes in the trench per WO 9614795.
Using a fork lift, eye bolts, shackles and lifting beam maintenance personnel attached these to the trench cover. The equipment was inspected per NSP rigging requirements. The trench cover was then lifted and moved back and set on the edge of the trench opening (refer to Figure 3).
1 l
Later a QC inspector arrived to witness the inspection of the RP/ST to charging pump piping.
When in the area of the trench, he noticed the concrete trench cover, that had been removed earlier, sitting along side the trench. Because of its apparent size and weight and the increased awareness on site concerning the movement of heavy loads, the inspector questioned if the removal of this trench cover fell under the requirements of D58 because of its weight and the RHR piping located in the trench. This concern was passed on to another QC inspector who determined that the weight of the cover met the definition of a heavy load (>1799 pounds), but the guidance in D58 did not specifically address the lifting and movement of the trench cover. Before moving the cover back the conservative approach was taken and a specific procedure prepared and approved for replacing the cover.
Inspection of the piping in the trench was completed.
2/28/97 WO 9701M e : place SI/RHR Trench Cover, was prepared and approved by the Operations Committee is uplacing the trench cover. The WO applied the requirements of D58 Appendix B and section 5.7 for moving a heavy load over equipment that is required to be operable.
3/3/97 The Unit 2 Auxiliary Building trench cover was replaced per the instructions of WO 9701169.
MC FORM 3SCA (4 99
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CAUSE OF THE EVENT
SUMMARY OF FACTORS THAT INFLUENCED HUMAN PERFORMANCE (First heavyloadlift)
In:ppropriate Action l: Failure to follow D58, Control of Heavy Loads, while moving 22 RCP rotor.
liabit intrusion - removal of 22 RCP rotor was performed based on similarities to past heavy load lifts with the reactor vessel head in place.
Mindset/ preconceived idea - the lead rigger felt that by informing the SS of the heavy load move he would be kept from making a heavy load move that wasn't allowed.
j Wrong assumotions made - the lead rigger assumed that a heavy load could be moved anywhere in containment with permission from the SS.
Insufficient degree of attention aoolled - before making the heavy load move, the system engineer, traveling maintenance supervisor, lead rigger and crane operator did not adequately apply D58 as instructed by the steps in D15.2.
Lack of_ specific knowledge - the system engineer in charge of the RCP work was not familiar with the D58 requirements for moving a heavy load in containment. The lead rigger and SS contacted were not aware of some of the specific D58 requirements that should be applied when the reactor head is off (e.g. heavy load can't come within 15 feet of irradiated fuel). The traveling maintenance supervisor and crane operator knowledge of D58 was limited to the pre-outage training received on the revisions made to D58 for SFP heavy loads.
Not familiar with task - the lead rigger was experienced in lifting heavy loads, but had not lifted 22 RCP rotor at a time when the reactor head was removed and the pool flooded. Note: In Unit 2 containment only 22 RCP rotor has to be transported across the refueling pool to get to the motor stand. The crane operator had not moved any heavy loads in containment before this outage.
SUMMARY OF CAUSES (First heavy load lift)
Inappropriate Action I: Failure to follow D58, Control of Heavy Loads, while moving 22 RCP rotor.
Primary Cause(s):
Work Practices - D15.2 procedure was not followed. D15.2 references that the heavy load be moved in accordance with D58 instructions and guidelines. D58 was not adequately applied before making the move to ensure that all the requirements were met (e.g., approved written procedure and containment isolated). The use of DSB for handling heavy loads ensures that load handling operations meet the safe load path requirements described in the plant's Design Bases Document for Heavy Loads.
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Work Organization / Planning -job scoping by the system engineer and the maintenance personnel did not identify the need for a specific written procedure and containment isolation to perform the heavy load lift.
Training / Qualification - a check of the training records could not determine if D58 refresher training had been provided over the years. Task analysis did not identify that requalification training was necessary for D58 and it appears that training was not coordinated over the years with the changes that were made to D58. Personnel involved with the initial move of 22 RCP rotor did not have an adequate understanding of D58 to know that additional requirements and precautions had to be taken before moving heavy loads in containment with the reactor vessel head removed.
It should be noted that adequate training was provided before the Unit 2 outage to address the most recent changes made to D58 for the control of heavy loads over the SFP enclosure.
Secondary Cause(s):
Verbal Cornmunication - During the phone conversation with the control room some pertinent information was not transmitted between sender and receiver because of limited knowledge of certain D58 requirements.
Second and third heavyloadlifts SUMMARY OF CAUSES (apparent)
Inappropriate Action (apparent): D58, Control of Heavy Loads, did not contain adequate information to pmvide guidance formoving heavyloads with the use of mobile cranes orfork lifts.
Primary Cause(s):
Change Management-The previous interpretation of NUREG-0612,' Control of Heavy Loads" and other original documents associated with the control of heavy loads did not identify mobile cranes or fork lifts as being in scope.
ANALYSIS OF THE EVENT
D sign Bases Document (DBD) for the Control of Heavy Loads (DBD TOP-08) provides the design bases and technical description for control and handling of heavy loads at Prairie Island. The primary document which governs heavy loads at the plant is procedure D58, Control of Heavy Loads, which was developed to be responsive to the requirements of NUREG-0612. The use of D58 for handling heavy loads ensures that load handling operations meet the safe load path requirements described in the DBD.
NRC FORM 3G6A 14 951
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First Heavy Load Lift in Violation of D58 Requirements:
Allload handling operations in containment are controlled by D58. This procedure contains general load handling precautions, including the restriction of carrying heavy loads in the vicinity of spent fuel and certain safety related equipment. This procedure requires load-specific procedures to provide d: tailed requirements for handling particular components. Where specific procedures have been prepared (e.g. reactor head, internals, and missile shields), they are referenced. For other heavy lords that may be identified (e.g. RCP motor, pump internals), D58 provides guidance for the preparation of specific load handling procedures including the requirements for defining a safe load
)
path consistent with NUREG-0612 and containment isolation requirements per a commitment to the i
NRC, which was incorporated into the Updated Safety Analysis Report (USAR).
Additional heavy load restrictions apply to loads being moved over or within 15 horizontal feet of irradiated fuel. NSP committed to having at least one isolation valve closed in each line which p:netrates the containment and provides a direct path from the containment atmosphere to the outside when a heavy load is moved over the reactor vessel. The containment isolation requirements are satisfied by refueling integrity AND by closure of the containment purge and inservice purge valves AND by CLOSING at least one door in each of the two air locks BEFORE performing a heavy load lift over irradiated fuel in the reactor vessel.
On 2/3/97, when preparing to lift and move 22 RCP upper bracket and rotor (heavy load), D58 j
requirements were not applied to ensure that specific heavy load handling requirements and heavy load restrictions for containment were met. The RCP rotor was moved without incident from the pump vault to the motor stand, but was transported over the irradiated fuel in violation of the D58 i
requirements and heavy load restrictions for moving a heavy load in containment with the reactor v:ssel head removed. At the time of the move both doors in the two airlocks were open along with the inservice purge valves being open. The inservice purge and its valves are automatically isolated by high radiation detected by Radiation Monitors 2R11/12 and 2R22. This automatic isolation of the inservice purge would have stopped any forced ventilation of containment. The violation of the DSB r:quirements and restrictions for this heavy load move was self-identified on 2/4/97, when preparing to move the RCP upper bracket and rotor back to the pump vault. Immediate action was initiated at this time to ensure that the movement of the rotor (heavy load) back to the vault was done in accordance with D58 for moving heavy loads in containment. This required preparing a specific written procedure p;r step 5.3.5 of D58 that ensured the heavy load would be moved within conditions specified in the DBD and with containment isolated. Once this procedure was prepared the Operations Committee r viewed and approved its use.
The heavy load was moved over the reactor core which contained irradiated fuel. The RCP rotor (heavy load) was in the vicinity of the core for approximately two minutes. The possibility of the heavy load being dropped was highly unlikely because of the safety factors of the rigging used and the jU.S. NUCLEAR REGULATORY COMMISSION 14 96)
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(11) inspection of the rigging prior to use. If the heavy load would have dropped when over the irradiated fu::l the potential consequences would have been significant. Based on plant calculations for the conditions that existed at the time, the thyroid exposure from the release of gas from 1 fuel element is 3.9 ren' at the site boundary. Since this event appears to be a precursor to an event with significant conseqtences and because of programmatic weaknesses, this event is considered to be significant.
Since this event appears to be a precursor to an event with significant consequences and because the d;fense in depth provided by administrative controls and training was degraded, this event is considered to be significant. The actual consequences of this event to the health and safety of the public were minimal since no failure occurred.
S:cond Heavy Load Lift Using a Mobile Crane:
The work orders for removing 21and 22 CW pump motors for cleaning and inspection addressed the use of a mobile crane to lift the loads from the CW pump bay of the Screenhouse and out through an opening in the Screenhouse roof. Before the mobile crane was used the inspection sticker posted inside the crane cab was checked to ensure that the crane had met its yearly inspection requirements.
The WOs included the weights of the pump and motor and precautions to have the crane chassis grounded and the nearby Unit 2 345 KV line isolated and grounded. The pump co,aponents were rigged by qualified NSP riggers who inspected and made sure that the rigging equipment used was adequate for the weight of the load being lifted. The system engineer conducted a pre-job briefing with the mobile crane operator, riggers and other personnel involved before each lift to discuss the safe load path, positioning of the crane and trailer, and to keep the mobile crane boom and the load clear of n:arby electrical equipment.
The circulating water pump WOs didn't define a safe load path nor was a safe load path area marked on the roof of the Screenhouse over the diesel cooling water pumps. The safe load path and areas to avoid when moving the load were discussed at the pre-job briefing. There are no potential adverse effects from dropping the heavy load since it followed a safe load path and would not have damaged safe shutdown equipment located in the Screenhouse.
Third Heavy Load Lift Using a Fork Lift:
The Unit 2 Auxiliary Building trench, where the cover was removed, contains the Train A RHR discharge piping to the St Pump suction and the RWST to charging pump suction line. At the time the trench cover was removed both trains of RHR were available with Train B in service. There were four available RCS make-up paths for inventory control, one of which was the RWST to the charging pump suction. The RWST to charging pump suction was also one of the three available boric acid flow paths.
The trench cover (approximately 6000 pounds) was lifted and moved using a fork lift rated at 10,560 pounds. The additional equipment used for rigging the trench cover was more than adequate to handle the weight of the cover. The rigging of the load followed standard NSP rigging requirements-
NRC F0FJ6 3 6 6 A U.S. NUCLEAR REGULATORY COMM10SION I4 951 LICENSEE EVENT REPORT (LER)
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Prairie Island Nuclear Generating Plant U2 05000 306 YEAR MUL H
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(17) and practices. The load was only lifted to a height of 1 inch above the floor and then moved back and set down at the edge of the trench. The possibility of the trench cover being dropped was highly unlikely because of the safety factors of the rigging equipment used and the rigging practices (lifting b am and a 4 point attachment).
R; portability The first heavy load lift was not in accordance with the Prairie Island Updated Safety Analysis Report, which states: "During heavy load lifts over the open fueled reactor vessel, at least one isolation valve will be closed in each line penetrating the containment which provides a direct path from the containment atmosphere to the outside." Therefore, this event is reportable pursuant to 10 CFR 50.73(a)(2)(ii)(B),"In a condition that was outside the design basis of the plant."
CORRECTIVE ACTION
immediate corrective actions 1.
Movement of 22 RCP upper bracket and rotor back to the stator placed on hold until a specific procedure could be written and approved by the OC. completed 2/4/97 2.
Work order 9700661, " Lift 22 RCP Upper Bracket and Rotor," written and approved to cover the move of 22 RCP upper bracket and rotor in accordar'ce with reactor building safe load path requirements per D58. completed 2/5/97 3.
General Superintendent of Maintenance issued a Training Request for training to review D58,
" Control of Heavy Loads", safe load pr.ths in the reactor building with Pl and traveling maintenance riggers and repairman. Course number: P8305L-105 rev. O training performed on 2/5/97 & 2/6/97.
4.
Communications made to Engineering, Maintenance and Operations personnel to increase their awareness of the recent events involving the movement of heavy loads and of the requirements of D58, Control of Heavy Loads and management's expectations to follow procedures.. Engineen'ng infonned 2/8/97. Maintenance informed 2/5/97 & 2/6/97, Operations informed 2/7/97.
5.
General Superintendent of Maintenance developed and issued a checklist to help Riggers, System Engineers and Maintenance Supervisors determine if D58 requirements should be applied prior to a heavy load lift. completed 2/12/97 6.
WO 9614600 attachment 1, for lifting and moving 21 CW Pump, prepared and approved by the OC. completed 2/21/97 7.
The General Superintendent of Plant Maintenance, Supt. Mechanical Systems, General NRC F03 36CA H 95)
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}U.S. NUCLEAR REGULATORY COMMISS3ON i
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Superintendent of Engineering, and system engineers are assisting with heavy load reviews for the interim until corrective actions #16 & 17 are implemented, completed 2/26/97 8.
All outstanding outage work orders reviewed to identify any work that would require a heavy load lift and require the preparation and approval of a specific procedure to cover the movement of the 1
heavy load. completed 2/26/97 9.
MSIP 6003, Control of Heavy Loads, written and issued.
completed 2/27/97
- 10. WO 9701169, " Replace SI/RHR Trench Cover", for moving the trench cover prepared and j
approved by the OC. completed 2/28S7
- 11. Conduct "just in time training" on MSIP 6003, Control of Heavy Loads for maintenance personnel.
}
completed on 2/28/97
- 12. Conduct "just in time" training on MSIP 6003, Control of Heavy Loads for construction personnel i
and other personnel who may have been missed. completed 3/3/97 1
- 13. Plant Manager held a meeting with the General Superintendent of Engineering, General Superintendent of Plant Maintenance, issues Training Manager, Error Reduction Task Force representative, Licensing and Management issues engineer, and design standards engineer on 3/5/97, to discuss the heavy load events of the outage and issues related to the control of heavy i
loads. completed 3/5/97 t
i
- 14. D58, Control of Heavy Loads, revised and revision 27 issued. completed 3/6/97
)
- 15. Perform heavy loads familiarization training for Engineering Support personnel, site Quality Services personnel, Nuclear Generation Services personnel, and Operations personnel.
completed 3/17/97 Long term conective actions:
\\
- 16. Perform a comprehensive review of the original source documents including NUREG-0612, Control of Heavy Loads, Phase I and ll Technical / Safety Evaluation Reports, related NSP-NRC correspondence, and Bulletin 96-02 documentation to determine the scope of the heavy loads program, including mobile cranes. Review DBD TOP-08 and related DBD, USAR, and D sections.
Determine if they adequately describe the scope of the program. Update license-related documentation accordingly. In addition, revise, as appropriate, D58, Control of Heavy Loads, related D sections,5AWI 8.6.0, Material Handling and Control of Heavy Loads, MSIP 6003, Control of Heavy Loads, to ensure these procedures are properly coordinated and that they implement the requirements for the control of heavy loads. Human engineering factors will be i.
- U.S. NUCLEAR R GULATORY COMMISS1Cj 14 95)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
DOCKET LER NUMBER (6) l PAGE (3)
Prairie Island Nuclear Generating Plant U2 05000 306 YLAR UuQAL RV N 15 OF 18 g
97 -- 01 --
00 (11 more space' 2s requ1 red, use additional copies at KRC Form 366A)
(17)
TEXT considered in such changes to reduce the likelihood of similar events in the future.
- 17. Assign a heavy loads program owner to be the focal point of the heavy loads program and the site expert for people to contact when questions arise on the control of heavy loads.
- 18. Conduct a job task analysis of the heavy loads program. Ensure this analysis includes and addresses the bullet items listed below.
Analyze the site organization (include travelers) and determine who needs D58 knowledge and skills training and how often. Conduct training for these groups / individuals on the Control of Heavy Loads.
Add a heavy loads sign-off requirement on the " Prairie Island /Monticello Overhead Crane Operator Qualification" form.
Establish a method that provides D58 initial and refresher training as determined by the analysis. Ensure the appropriate traveling maintenance personnel coming to PI for the outage are included in this refresher training.
Ensure that initial training is provided for maintenance personnel who transfer to PI from other NSP plants.
- 19. The maintenance, operations, and engineering training PACS will review D Sections in order to identify procedures that require job and task analyses. Identified D Sections will have job and task analyses performed.
- 20. Outage planning group will develop a method that will consider / identify the movement of heavy loads in future outage planning and schedules. We will consider tying this to the Shutdown Safety Assessment checklist.
FAILED COMPONENT IDENTIFICATION Th:re were no failed components associated with this event.
PREVIOUS SIMILAR EVENTS
Two non-reported events have occurred at Prairie Island:
NRC Inspection Report b5012 (10/27/95)- underestirnated the weight of high pressure turbine enclosures Prairie Island NCR 2010568 -location of heavy loads on the turbine floor nc rm assw es
.U.S. NUCLEAR R.GULATORY COBetISSIC.J M 951 LICENSEE EVENT REPORT (LER)
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DOCKET LER NUMBER (6)
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Prairie Island Nuclear Generating Plant U2 05000 306 YEAR stu t
ntvm 16 OF 18 00 i
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NkC FORM 366A U.S. NUCLEAR REGULATORY COMM8SSICCJ I4 95)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
DOCKET LER NUMBER (6)
PAGE (3)
Prairie Island Nuclear Generating Plant U2 05000 306 YEAR bluutNiiAt utvisuN 17 OF 18 NUMBER NUMBER 97 -- 01 --
00 4
TEXT (Jt enore space as requ2 red, use add 2 c2onal cop 2es of NRC Forin 366At (17)
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NRC PORK 366A U.S. NUCLEAR REGULATORY COBOLISSICJ i
M 99
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LICENSEE EVENT REPORT (LER) t TEXT CONTINUATION j
FACILITY NAME (1)
DOCKET LER NUMBER (6)
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Prairie Island Nuclear Generating Plant U2 05000 306 YEAR bluutNHAL MtVWUN 18 OF 18 NUMBER NUMBER i
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