ML19093B079
| ML19093B079 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 12/06/1977 |
| From: | Stallings C Virginia Electric & Power Co (VEPCO) |
| To: | Case E, Reid R Office of Nuclear Reactor Regulation |
| References | |
| Download: ML19093B079 (5) | |
Text
'
December 6, 197T Mr. Edson.G. Case; Acting Director Office of Nuclear Reactor Regulation Attn:
Mr. Robert W. Reid, Chief Operating Reactors Branch No. 4 Division of Operating Reactors*
U. S. Nuclear Regulatory Commission Washington~ D. c.
20555
Dear Mr. Case:
Serial No. 425/091477 LQA/ JLP : kbo.
Docket Nos.
50-280 50-281 This is in reference to your.letter of September 14, 1977, concerning fracture toughness and potential for lamellar tearing of steam generator and reactor coolant.pump support.materials.
Enclosed is a response which addresses most of the specific requests for information.
Because of the significant difference in design concept be-tween the Surry and North Anna supports;.we have not addressed in detail some of the specific items you requested believing.that they would not be relevant to your concerns.
However, after your review of this information and the in-formation already available in the Surry FSAR, Section 15.6.2 and if it is con-cluded that more specific detail information is still required, please advise.
In regard to item 2 and the last paragraph of your letter, we expect to submit for your review this information and our fracture toughness evalua-tion of the Surry steam generator and reactor coolant pump support materials by March 1, 1978*.
Enclosure
/
Enclosure to letter Serial No. 425/091477
- Page 1
- l.
Provide engineering drawings of the steam generator and reactor coolant pump suppor~s sufficient to show the geometry of all principal*
elements.
Provide a listing of materials of construction.
Response
The Surry FSAR, Figures 15.6-2 and 15.6-3 show the geometry of the steam generator and reactor coolant pump supports.
A bill of material lJsting is shown in the upper right hand corner of these figures.
In addition, the following detail drawings which include materials listing are attached:
RC eump support drawings 11448-FM-53A, Rev. 5 11448-FM-538, Rev. 4 11448-FM-53C, Rev. 4 11448-FM-53D, Rev. 4 11448-FM-53E, Rev. 3*
11448-FM-53H, Rev. 4 Steam generator support drawings l l448-FM-5lA, Rev. 8 11448-'FM-518, Rev. 10 11448-FM--510, Rev. 5 11448-FM-SlE;. Rev. 6 11448-FM-51 F, Rev. 4 114118-FM-51 K, Rev. 3 1 l 44 8-FM-51 L, Rev. 6 11448-FM-51 M, Rev. 3 l 1448-FM-51Q, Rev. 2 l Jl148-FM-51R, Rev. 1 11448-FM-51 S, Rev. 4
- 2.
Specify the detailed design loads used in the analysis and design of the supports.
F°or each loading condition (normal, upset, emergency and faulted), provide the calculated maximum stress in each principal element of the support syitem and the corresponding allowable stresses.
Response
The Surry FSAR, paragraph 15.6.2 discusses the design bases.
(detailed design loads must come from S&W).
. -7{.':)"
,./-.____J
Enclosure to letter Serial No: 425/091477
- P_age 2
- 3.
Describe how all heavy section intersecting member weldments were designed to minimize restraint and lamellar tearing.
Specify the actual section thicknesses in the structure and provide details of typical joint designs.
State the miaximum design stress used for the through-thickness direction of plates and elements of rolled
- shapes.
Response
The Surry steam generator and reactor coolant supports do not have any heavy section ihtersecting member weldments.
- 4.
Specify the m1n1mum operating temperature for the supports and describe the extent to which material temperatures have been measured at various points on the supports during the operation of the plant.
Response
In connection with developing information for North Anna support problem, temperatures of the ambient In the Surry, Unit #2 containment adjacent to the steam supports were measured during operation at 100% power.
temperatures ranged from 83.2°F min. in October 1975 to 91.6°F min. in August 1975, the air generator These There have been no temperature measurements made on the supports themselves, but it is postulated that these would be at or above ambient air temperatures.
.... ~};~
~ 1 -*
Material Spec.
A-l06grB Enclosure to letter Serial No. 425/091477
- Page 3
- 5.
Specify all the materials used in the supports and the e~tent to which mill certificate data are available.
Describe any supplemental requirements such as melting practice, toughness tests and through-
.thickness tests specified.
Provide the results of all tests that may better define the properties of the materials used.
Response
Below is a listing of the major materials used in the construction of these supports.
Included are copies of the portion of S&W specification*
which detail the special tests required for the high strength ste~l and casting materials.
Also we have included the available test reports which show the results of the testing performed on the major castings and high strength steel materials.
RC Pump Support Materials Product Supplemental Toughness Mi 11 Test NDE Remarks Form Requirements Tests Reports 1411' 611 X
- yes pipe and forgings pipe A-105 Gr II forging X
none none yes yes AISl-11340
- forging, none none yes no plate Vascomax CVM forgin~s yes yes yes yes See S&\\.J Spec. NUS-198 350 & 300 A-285 grC plate none none yes no A-193 grB7 bar none none yes no Steam Generator Support Materials A-352grLC3 casting*
yes yes yes yes See S&W Spec. NUS-22 mod.
Vascomax CVM forging yes yes yes yes See S&W Spec NUS-198 350 & 300 A-l06grB 1411 pipe X
none none yes yes
. ~ ~--,*--:-**-....... --
.,.* _,..,.,,,,,.......... --,...,...,..,....,........ *., '*r*~,.....,.. *--~-.. -*, ***~~--.**
-~*.,
. ***,"'!/!
. (.
P_age 4 Enclosure to letter
~
Serial No. 425/091477
- 6.
Describe the welding procedures and any special welding process requirements that were specified to m1n1m1ze residual stress, weld and heat affected zone crackihg and lamellar tearing of the base metal.
Response; There were no special welding processes used to m1n1m1ze residual stresses and any welding that was done was performed in accordance with Section IX, ASME Code.
7, Describe all inspections and non-destructive tests that were petformed on the supports during their fabrication and installation, as wel 1 as any additional inspections that were performed during the life of the facility;
Response
In addition to numerous inspections and tests carried out by the material suppliers and fabricators all of the components for these supports were subject to inspectio~ duiing fabrication and installation by Stone & Webster Engineering Corp.
Records of these inspections are available for review.
All w~lds were subjected to examination by either the magnetic particle, liquid penetrant or radiographic methods.
The Vascomax 350.CVM and 300 CVM materials and the A-352 gr. LC3 casting materials were subjected to examination by the magnetic particle and ultrasonic methods.
The available test and inspection results are included in the test reports submitted-under item 5, A visual inspection of a portion of these supports is requirid by the Tec~nical Specification, however, there is no forma 1
- inspection program for a 11 components of the supports during the life of the facility.