ML20040G893
| ML20040G893 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island, Fort Calhoun  |
| Issue date: | 02/03/1982 |
| From: | Mayer L 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 GL-81-07, GL-81-7, NUDOCS 8202160589 | |
| Download: ML20040G893 (4) | |
Text
-
gy J)
Cb, Northem States Power Company 8
h 414 Nicallet Mall
%CCM Minneapohs, Minnesota 55401 Telephone (612) 330-5500 E
FEB12198 F @
' su,re*g tut.
Il '
February 3, 1982 g
p Director Of fice of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington, D C 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Control of Heavy Loads (Special Lif ting sevicesl Attached is the investigation concerning Special Lifting Devices mentioned in our six-month submitt al dated August 31, 1981. This investigation is submitted in response to Mr Eisenhut's letter dated December 22, 1980, titled Control of Heavy Loads.
One item remains unresolved to date; ie, the turbine building crane response to Item 2.4.2(b) of the nine-month submittal dated December 9, 1981. The completion target date for this investigation is July 1, 1982. Should there be any changes in this target date we will notify you.
. h.
L 0 Mayer, PE Manager of Nuclear Support Services LOM/TMP/bd Attachment ec:
Regional Admin-III, NRC NRR Proj Mgr, NRR NRC Resident Inspector G Charnoff 9
8202160509 820203 I
PDR ADOCK 05000285
(
P PDR
J.
' CONTROL OF. HEAVY! LOADS:
.SPECIAL LIFTING DEVICES.-
1 NORTHERN STATES" POWER COMPANY-PRAIRIE ISLAND e
'A.-
REACTOR'. VESSEL' HEAD'AND INTERNALS LIFTING-RIGS The reactor-vessel head and internals lifting rigs were: designed.
and' built about 1970-1971. 'At that time, the general design criteria' required the resulting stress in thefload carrying members, when.-subjected-to the total: combined: lifting weight,
~
should not exceed'one fifth (1/5) of1the: ultimate strength of the material.
No formal. stress report was preparediand no design: specifications were written.
Westinghouse defined the design,Lfabrication and.qualityJassurance requirements on de :
tailed. manufacturing drawings and purchase order documents.
Westinghouse issued the field assembly *and operatingtinstruc -
tions which included an initial load test.- Westinghouse 's objective was to' provide a quality product and_this product was designed, fabricated, assembled and inspectedLin accord-ance with internal Westinghouse requirements.
In-general, 1
Westinghouse requirements' meet the intent'of ANSI N14.6Ebut:
not.all the. specific detailed requirements.
The review of-the lifting' devices has determined!that-these devices are: not.in strict. compliance with :all =the ANSI-N14.6 requirements.
Listed below is a tabulation of1these.parc-
. graphs.and associated. Westinghouse remarks.'
la. ' Requirement:
Para. 3.2.1.1.--requires the design, when using materials with yield: strengths' above 80% of their ultimate strengths,
~
to be' based on :the ' material's fracture toughness and not -
the listed design factors..
lb.
Remarks:
High strength materials are used in these devices and the fracture toughness was not determined.
However, the:
stress design factors listed'were used in the analysis' and the resulting stresses are withig the allowable stresses.
2a.
Requirement:
Para. 5.1 lists owner responsibilities and 5.1.1 and 5.1.2 requir'es the owner to verify that the special lifting devices meet the performance criteria of the d i gn'speci-ficatifsby'recordsandwitnessoftesting.
IT r:-
~
e
-2b.
Remarks:
'Since:there wasn't a'y design-specification-for these rigs--
n
- and 150% loaditesting_wasenot. originally requiredtor per -
~
formed,.the-utility.obviously'can't comply.
However,' the-. -
W-Quality-Release'may be' considered"an1 acceptable 1 alternate.
to verify'that the criteria for. certified material-testing.
. reports, non-destructive;testingLand' documentation required byfthe Westinghouse drawings and_ purchasing document was satisfied.
Although proof and l functional testingLwasl not:
~
required,lthe site _ assembly instructions' require,yafter; initial-assembly in site, the~following:
~
Raising the_ rig,' assembled to.its : respective attachment,
~
slightly:above the-supporting surface to be. free hanging'
.for one-half hour.- During this-time, visually inspect for. signs of--distressLor_ distortion.
Lowering?the rig to-
~
'its support and performing NDT-visual and mag.Lparticle inspections of critical welds.
It can'be se'e to assume that these~100% load tests were performed and acceptable.
since.-the rigs have been-in operation for about 10. years.-
3a.-
Requirement:
5.2 and 5.3 - Acceptance. Testing and Testing to Verify Continuing Compliance - These paragraphs require.the rigs-to be initially tested at'150% maximumiload followed.by non-destructive testing of critical' load bearing parts and welds and also annual 150% load. tests'or annual non-destructive tests'and examinations.
3b.
Remarks:
See Remark'2(b) also -'The: original rigs were loadLtested to only 100% of the. load.
A; visual inspection including
~
NDE testing of' major load' carrying welds and any other-critical areas 'will be done prior to each use (typically at each refueling).
I 4.-
Discussion of the Design Criteria for a Stress Design Factor f
j NUREG 0612, paragraph 5.1.l(4) states that special lifting i-devices'should satisfy the-guidelines of~ ANSI N14.6.
l Further, NUREG 0612, 5.1.1(4) states:-'"In addition, the p,
stress design factor stated in Section 3.2.1.1 of ANSI L
N14.6 should.be based on'the combined maximum static and
~
dynamic loads'that could be imparted on the, handling i-device based on characteristics of the' crane which will
~
be used.
This is in lieu of the guideline in Section j.
j.
1 I.i
3.2.1.1-of ANSI N14.6'which bases the stress design factor on only the weight (static load) of the load and_of the-
' intervening' components of the special handling device".
The dynamic characteristics of the crane would be based on the main hook and associated wire' ropes holding the hook.
Most main containment cranes-use 16 or more wire ropes to handle the load.
Should the crane hook suddenly-stop during lifting or lowering a= load, a shock load could be impacted by the connected device.
The maximum design factor that is recommended by most design' texts
'is a factor of 2 for11oads that are suddenly applied.
The stress design factors-required in Section 3.2.1.1 of ANSI N14.6 are:
3 (weight) < Yield Strength 5 (weight) < Ultimate Strength The factor of 3 specified, certainly, includes considera-tion of suddenly applied loads for cases where the dynamic impact factor may be as high as 2.0.
For typical contain-ment cranes, the dynamic factor is much closer to 1.0.
Thus, we feel that the use'of the design criteria in ANSI N14.6 satisfies the NUREG requirement.-
To provide flexibility on stress design factor,_the analysis of the devices (on each component that comprise these lifting devices) was performed with design factors of 1, 3, and 5.
The results of the analysis' indicate that all stresses are below the required acceptable limits.
In all cases, using a stress design factor of 5 resulted in stress limits below the yield strength of the material.
B.
TURBINE LIFTING RIG The turbine component lifting rig was designed by Westinghouse.
prior to the existence of ANSI N14.6 and ANSI B30.9 1971.
Additionally, this device was designed as not having any nuclear significance since it is to be used only in the turbine building.
Documentation is not available to assure that all of the require-ments of the two standards are met.
Our review did include a review of Westinghouse provided drawings that were available.
The information reviewed to date does indicate sound engineering practices were employed and there is reasonable assurance that the intent of the standards was in fact accomplished in the design and fabrication of the lifting rig.
Furthermore, this device has been used to transport the loads for which it was designed to handle many times with no indications of design deficiencies.
Additionally, a visual inspection including NDE testing of major load carrying welds and nay other critical areas will be done prior to each use (typically at each refueling).
_a