ML20073E100
| ML20073E100 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/08/1983 |
| From: | Musolf D NORTHERN STATES POWER CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| REF-GTECI-A-36, REF-GTECI-SF, RTR-NUREG-0612, RTR-NUREG-612, TASK-A-36, TASK-OR NUDOCS 8304140341 | |
| Download: ML20073E100 (11) | |
Text
a Northem States Power Company 414 Nicollet Mall M.nneapohs. Minnesota 55401 Telephone (612) 330 5500 April 8,1983 Director Of fice of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington, DC 20555 PRAIRIE ISL\\ND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Control of Heavy Loads - Six Months Report Items Attached for your information is our response to Staf f concerns on the Control of Heavy Loads - Six Month Submittal (letters dated August 31, 1981 and November 8, 1982) expressed during the March 18, 1983 meeting between NSP and the Staf f.
Please call us if you have questions concerning this response.
bbMW D M Musolf Manager - Nuclear S ort Services DMM/TMP /j s cc:
Regional Administrator-III, NRC NRR Project Manager, NRC tmC Resident Inspector C Charnoff Attachment l
D 8304140341 830408 PDR ADOCK 05000282 P
L Prairis Isicnd Nuclear Gen rsting Picat April 8, 1983 Response to Staff Concerns on the Six M nth Control of Heavy Loads Submittal o
- 1. NSP should develop and implement safe load paths for major heavy loads which are handled by the reactor building polar cranes.
Development of such a program should consist of determination by engineering staff review of the optimum load path or corridor, formalization in drawings and inclusion in appropriate procedures, and development of suitable visual aids to aid the crane operator and ensure compliance without regard for load categories, system redundancy, and intervening floors.
RESPONSE
All load handling operations in containment are controlled by the plant procedure D58. For certain loads (ie, Reactor Head, upper internals, etc.)
reference is made to other specific procedures which deal with handling of that particular component.
Instructions are provided that when a "new" heavy load is identified, guidance is provided as to what considerations must be addressed in generating a load handling procedure. These considera-tions include:
1)
Identification of load to be moved.
2)
Inspection and acceptance criteria required before movement of the load.
3)
The steps and proper sequence to be followed in handling the load.
4)
Defining the safe load path in accordance with NUREG-0612.
5)
Special Precautions Any new load handling procedure or revisions to existing procedures require plant Operations Committee review in accordance with plant administrative procedures.
Additionally, at least one man of the load handling crew, in addition to the crane operator will be responsible for ensuring that the defined safe load path is followed.
- 2. NSP should establish exclusion areas for the turbine building main steam and feedwater piping and the auxiliary building BASTS similar to the area established for the 4.16-kV switchgear.
RESPONSE
An exclusion area has been established above the auxiliary building BASTS similar to the area established for the 4.16 kV switchgear.
It has been determined that the turbine building main steam and feedwater piping are not required for safe shutdown or decay heat removal and heavy load handling restrictions are therefore not required..
NSP should conduct a load tsst of special lifting devices in accordance with ANSI N14.6-1978.
RESPONSE
Three special handling devices were identified at Prairie Island; Reactor Internals Lifting Rig, Reactor Head Lifting Rig, and the Turbine Components Lifting Assembly. Each of these devices will be discussed separately below.
Internals Lifting Rig:
The internals lifting rig is designed to lift both the lower internals and the upper internals. The lower internals have been lifted and are greater than twice the weight of the upper internals.
Since the load of concern is upper internals (lifting while fuel is in the reactor), a load test has indeed occurred.
Reactor Head Lifting Device:
Figure 1 is a sketch of the Reactor Head Lifting Device. The three vertical legs and control rod drive mechanism platform assembly are per-manently attached to the reactor vessel head lifting legs.
The tripod assembly is attached to the three vertical legs and is used when in-stalling and removing the reactor vessel head. During plant operations, the sling assembly is removed and the three vertical legs and platform assembly remain attached to the reactor vessel head.
As can be seen from the sketch the lifting device is a rather simple mechanical device with mostly pin connections.
Table 1 summarizes the stresses on each of the parts which make up the Reactor Head Lifting Device. All stresses are below the ANSI N14.6 allow-able limits [3(weight) < Yield Strength, 5(weight) < Ultimate Strength].
Turbine Components Lifting Assembly Figure 2 is a sketch of the Turbine Components Lifting Assembly.
The device is used as a spreader assembly for disassembly and reassembly of turbine components. This device is used in conjunction with slings to carry large turbine components.
Table 2 summarizes the stresses on each part which make-up the Reactor Head Lifting Device. All stresses are below the ANSI N14.6 allowable limits.
General Since the above summarized analysis shows sufficient margins to yield and ultimate strength exist, we conclude the devices meet the intent of the ANSI N14.6 standard.
Furthermore, prior to use during an outage certain inspections are conducted to insure the devices continue to comply with the standard.
Visual inspection will occur at each outage prior to use of the device. Additionally the specific lifting devices will be included in the plant N.D.E. program so that welds and other critical areas are in-spected at an interval consistent with other safety-related components.
1 l
6" DI A. PIN TOP LUG g
SIDE L'lG CLEVIS 5
s i
i 4
4" DI A. PIN UPPER LEG 6 i,
)
LUG 10 7 CLEVIS i
g ARM 4" DI A. PIN 6
o t
CLEVIS t
M 11 4" DIA. PIN n
ii
!i l1 i !
n t
f 4
LOWER LEG
\\
CLEVIS i
i 3" DI A. PIN 15 I
l Figure 1 Reactor Yessel Head lift Rig I
i
0
=
ai i
o4 I n.
n 6
s-
=
[
/
]
mm em FIGURE 2 'IURBINE CGTCNENTS LIFI'ING ASSDELY
TABLE 1
SUMMARY
OF RESULTS REACTOR VESSEL HEAD LIFT RIG Calculated Stresses (ksi)
Haterial Allowable Item (a).
Part Name Value (ksi)
No.
And Material Designation W(b) 3W SW S ("}
S
(
ult 1
6" Dia Pin Bending.
13.75 41.25 68.75 120 135 A434 Shear 3.31 9.93 16.55 AISI 4340 Bearing 4.98 14.94 24.9 CL BD 2
Top Lug Tension @ Hole 6.25 18.75 31.25 38 70 A 515 GR 70 Shear @ Hole 5.35 16.05 26.75 Bearing 6.21 18.63 31.05 3
Side Lug Tension @ Hole 3.82 11.46 19.1 38 70 A515 GR 70 Shear @ llole 3.82 11.46 19.1 Combined Bending & Tension 5.13 15.39 25.65 Shear 1.73 5.19 8.65 Bearing 5.71 17.13 28.55 (a) See Figure 5-1 for location of item and numbers and section (b) W is the total statis weight of the component and the lifting device (c) S is the yield stregth of the material (ksi)
(d) S is the ultimate stregth of the material (ksi)
W
a TABLE 1
SUMMARY
OF RESULTS REACTOR VESSEL IIEAD LIFT RIG Calculated Stresses (ksi)
Material Allowable Item (a)
Part Name Value (ksi)
(
No.
And Material Designation W(b) 3W SW S(
Sdt 4
4" Dia Pin Same as Item 8 Same as Same as Same as 110 140 A434 CLBD Item 8 Item 8 Item 8 AISI 4340 5
Clevis Same as Item 7 Same as Same as Same as 30 60 A105 GR1 Item 7 Item 7 Item 7 6
Upper Leg Tension @ Thread 6.19 18.57 30.95 35 70 A306 GR70 Shear @' Thread 1.91 5.73 9.55 Tension @ 4" Dia lloie 5.46 16.38 27.3 7
Clevis Tension @ !! ole 4.28 12.84 21.4 30 60 A105 GRI Shear @ liole 2.14 6.42 10.7 Bea ring 5.99 17.97 29.95 Tension @ Th'd Relief 2.21 6.63 11.05 Shear * @ Thread 1.89 5.67 9.45 8
4" Dia Pin Bending 10.59 31.77 52.95 110 140 A434 CLBD Shear 2.73 8.19 13.65 AISI 4340
TABLE 1
SUMMARY
OF RESULTS REACTOR VESSEL HEAD LIFT RIG Calculated Stresses (ksi)
Haterial Allowable Item (a)
Part Name Value (ksi)
No.
And Material Designation W(b) 3W 5W S (*}
S,y (d) 9 Arm Compressive (Buckling) 1.97 5.91 9.85
(*)F = 20.4 c
A106 GRB Shear @ Weld 1.097 3.29 5.48 35 70 Compression @ Weld
.633 1.89 3.16 35 70 10 Lug Tension @ Hole 5.72 17.16 28.6 35 70 A516 GR70 Shear 5.72 17.16 28.6 Bearing 5.72 17.16 28.6 11 4" Dia Pin Bending 9.62 28.86 48.1 110 140 A434 CLBD Shear 2.48 7.44 12.4 AISI 4340 Bearing 5.19 15.57 25.95 12 Clevis Tension @ Hole 3.89 11.6 19.45 30 60 A105 GR1 Shear @ Hole 1.95 5.85 9.75 Bearing 4.07 12.21 20.35 Tensibn Th'd Relief 2.13 6.39 10.65 13 Lower Leg Tension @ Thread 5.62 16.86 28.1 35 70 A306 GR70 Shear @ Thread 1.73 5.19 8.65 Tension @ 4" Dia Hole 4.96 14.88 24.8
(*)
F is the compressive buckling strength of the material (ksi)
TABIE 1
SUMMARY
OF RESULTS REACTOR VESSEL HEAD LIFT RIG Calculated Stresses (ksi)
Material Allowable Item (a)
Part Name Value (ksi)
No.
And Material Designation W(b) 3W SW S (C)
S,gt 14 Clevis Tension @ Hole 2.68 6.04 13.4 30 60 A105 GR1 Shear @ Hole 1.34 4.02 6.7 Bearing 4.67 14.01 23.35 Tension @ Th'd Relief 1.72 5.16 8.60 15 3" Dia Pin Bending 20.18 60.54 100.9 110 140 A434 CLBD Shear 3.79 11.37 18.95 AISI 4340 Bearing 8.93 26.79 44.65 w
w
I, l
TABLE 2 l
SUMMARY
OF RESULTS TURBINE COMPONENTS LIFTING ASSEMBLY Calculated Stresses (ksi)
Haterial Allowable Itea (a)
Part Name Value (ksi)
No.
And Material Designation W(b) 3W SW S(}
S,gg( }
1 W36x182 Beam Bearing 10.11 30.33 50.55 36 58 Shear 3.13 9.39 15.65 36 58 Bending 10.8 32.4 54.0 36 58 2
Beam Ifanger Bearing 8.80 26.4 44.0 35 65 Shear 1.27 3.81 6.35 35 65 Tension 5.60 16.8 28.0 35 65 Weld 3.61 10.83 18.05 70 3
Sling 1.75" Tension 23.1 69.3 115.5 125 250 4
Lifting Pin Shear 4.80 14.4 24.0 30 55 S&6 Yoke Strongback Bending 4.51 13.53 22.55 35 65
& Bearing Plate Sheat 1.23 3.69 6.15 35 65 7
Yoke Strap Bearing 6.17 18.51 30.85 35 65 Tension 5.35 16.05 26.75 35 65
i TABLE 2
SUMMARY
OF RESULTS TURBINE COMPONENTS LIFTING ASSEMBLY Calculated Stresses (ksi)
Material Allowable item (a)
Part Name Value (ksi)
(d)
No.
And Material Designation W(b) 3W SW S (C}
S,7 8
Shackle Bar Bearing 4.49 13.47 22.45 35 65 Shear 1.59 4.77 7 95 35 65 Bending 6.01 18.03 30.05 35 65 9
Shackle 2.5" Tension 40.1 120.3 200.5 325 650 O
O J