ML19319D756
| ML19319D756 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 07/17/1972 |
| From: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Mallay J BABCOCK & WILCOX CO. |
| Shared Package | |
| ML19319D748 | List: |
| References | |
| NUDOCS 8003250760 | |
| Download: ML19319D756 (4) | |
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.N b,'.172D STATES
((.N' M ATOMIC D!ERGY COMMISSION
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W ASn eNGTON. O.C. 20545 JUI.17 U72 Mr. Ja=es F. Mallay Manager, Licensing Nuclear Power Generation P. O. Box 1260 Lynchburg, Virginia 24505
Dear Mr. Mallay:
We have cocpleted our initial review of your topical report BAW-10047,
" Study of Discontinuities in Control Rod Drive Motor Tube Extensions,"
add find that we need additional infermation to complete our evaluation.
The specific information required is ested in the enclosure. Much of this information was discussed with your representatives on July 7, 1972 at a =eeting in Bethesda, Maryland.
In general, we find your investigation into the cause of the discontinuities and your subsequent inspectica program adequate. However, before our final acceptance, we will require a co:pletely adequate response to the
- information rea.uested, revision or supplementation to your topical report to reflect this additional information, and incorporation of this topical report with revisions or supplements in all appropriate applications.
In addition, we will also require a testing program and surveillance program.
The testing program will verify the predictions of the temperature response of the C"DM tube extensions on a statistically significant number of assemblies during the preoperational and startup tests for the first facility utilizing these redesigned units. The surveillance program will assure that the maximum temperature of the CRDM tube extension does not approach the revised design temperature during plant operation.
The additional information and your response to our requirements should be provided i'n accordance with the review schedules we have established for those applications affected by this matter. We understand that you are aware of these schedules through your nor=al communication channels with the respcetive applicants and will inform them of your schedules for responding to our needs.
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8003250 76 0 i
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JUL 17 ~
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Mr. James F. Mallay 2-9 Please contact us if you desire any discussion or clarification of the material required.
Sincerely, l
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R.' C. DeYour/g, Assi'utant Director for Pressurized Water Reactors Directorate of Licensing
Enclosure:
Request for Additional Infor=ation 6
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r, REQUEST FOR ADDITIONAL INFORMATION BA3 COCK & WILCOX TOPICAL RE?OIT, 3AU-10047 1.
Provide more information describing the conditions of each test in Table 7-1, such as air flow conditions, insulation, thermal barrier, 1
and drive activity.
2.
Supply all data used to conclude that 450*F is the maximum temperature which could occur. Supply data used to justify statements 3, 4, and 5 on page 7-2.
3.
Define the drive activities, cycling and intermittent tripping, to include the speed, frequency and length of the rod covement for each activity.
4.
Was the test facility used for these tests shown in B&W topical report, BAW-10029? If so, provide the flov velocity in the vicinity of the CRD Motor Tube flange and compare this to the Oconee 1 hot function:1 test results and updated velocities from your additional model testa.
5.
Supply all test results from Oconce 1 that would be appropriate for this subject.
6.
Provide the maximum temperature increase expected for one full length trip.
7.
For the situation where stator cooling water is lost, but electric power to the stator is still supplied, (1) show that the integrity of the reactor coolant pressure boundary and the functionality of the control rods are maintained, or (2) show that sufficient time and suitable instrumentation are available to prevent the above from happening.
In either case provide a conservative " worst case" analysis including the effee of single failures.
8.
Provide the " worst operating conditions as defined by the design speci-fications" referred to on page 7-2.
9.
Revise your predicted maximum =otor tube axtension to include the maximum outlet temperature of 619'F.
10.
State the validity of these tests and analyses for all types (A.B.C) of B&W CRD.
11.
Discuss the effect of venting the CK3 on the netor tube entension temperature.
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12.
Provide data to show the transient ter.perature behavior of the extension for the various test and operating conditions.
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