ML19319C083
| ML19319C083 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 01/24/1973 |
| From: | US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML19319C074 | List: |
| References | |
| NUDOCS 8001310455 | |
| Download: ML19319C083 (2) | |
Text
.
O-m o
TOPICAL REPOPT EVALUATION
,paportIdenci[ication:
BAW-10007, Rev. 1; BAW-10029 Report
Title:
Control Rod Drive Mechanism Test Program L
Report Dates: June 1971 and January 1972 Originating Organization: Babcock & Wilcox Reviewed By: Mechanical Engineering Branch, AEC Directorate of Licensing November 1972
SUMMARY
OF TOPICAL REPORT:
Control rod drive mechanism tests were carried out under operating coolnnt flow, temperature, pressure and water chemistry conditions and varyinp, the equipment alignment from optimum to the maximum amount of misalignment expected with the most adverse combination of design col-orances.
In addition, a test was completed to ' confirm the motor's ability to provide for forced insertion in the event of a stuck rod.
l Life tcscing was carried out under the misalignment conditions and duplicating the stroke, travel and reactor trips expected during 20 years of service life. Trip times, deacceleration rates and component wear were measured in conjunction with the life tests, and insurcion force was measured under the stuck rod conditions. All test results were judged to comply with the performance criteria specified and were considered satisfactory.
SUMMARY
OF RECULATORY EVALUATION:
1 We have reviewed the subject reports and find that the three specific versions of a basic roller nut drive mechanism designated "A'.', "B" and "C" by 3 & W exhibit satisfactory trip, wear, acceleration, and forced insertion characteristics in operation. However, the reports are considered acceptable only if the provisions stated below in the regu-latory position are satisfied.
Pressure boundary design criteria and stress limits except for the OBE and DBE under various operating conditions are not presented for 4
the type "A" mechanism. Zero period ground accelerations of 0.25 g horizontal and 0.3 g vertical equivalent static accelerations were used for seismic analysis. Type "C" components are designed and manufactured to the Class A vessel requirements of Section III. How-aver, specific stress limits for emergency and faulted operating conditions, and the seismic design input loadingsare not specified.
The design crito-ia used for the design of type "B" mechanisms which are hybridized version of types "A" and "C" mechanisms are also not described..
6 S
- - + - -.
-aw.---.
+,--g
-y W
w--r-2a 7
e-y
e.
~
\\
e 2-TOPICAL REPORT EVALUATIOF REGULATORY POSITION:
The subject reports provide a satisfactory basis for accepting the operating performance of 3 & W control rod drive mechanisms Type "A",
"B", or "C" arid may be referenced in future case applications provided that:
(a) the purpose of reference is limited to only mechanism operating characteristics and (b) the analytical methods, criteria and stress limits used in the design of the mechanisms and (c) life tasting or equivalent procedures are used to confirm service life beyond the 20 years demonstrated by the test program are submitted..
Items (a), (b) and (c) must be evaluated on a case-by-case basis.
e e
a e
o e
e O
e.1 i
,