ML18233A114
| ML18233A114 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 06/11/1982 |
| From: | Dale L Mississippi Power & Light Co |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Algama D, D. Marksberry | |
| Shared Package | |
| ML18233A113 | List: |
| References | |
| 0260/0756 | |
| Download: ML18233A114 (4) | |
Text
MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi P. 0. BOX 1640. JACKSON, MISSISSIPPI 39205 NUCLEAR PRODUCTION DEPARTMENT June 11, 1982 U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D. C.
20555 Attention:
Mr. Harold R. Denton, Director
Dear Mr. Denton:
SUBJECT:
Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416 and 50-417 File 0260/0756 Local Detonations AECM-82/266 Representatives of Mississippi Power & Light Company (MP&L) met with Sandia on Wednesday, May 19, 1982, to discuss the Sandia Local Detonation Evaluation of GGNS in progress for the NRC.
In this meeting, a local detonation size was agreed upon as the best representative volume for the above evaluation.
This volume was agreed to by the NRC and an evaluation was carried out by Sandia.
Based upon our review of the Sandia evaluation, no compromise in containment integrity resulted.
The MP&L evaluation is attached for your information.
It is our understanding that this completes the efforts in the local detonation area; and, as satisfactory results have been achieved, no further action is required by MP&L.
RMS/SHH/JDR:nll Attachment cc:
(See Next Page) 8206140086 820611 PDR ADOCK 05000 416 A
PDR Yours truly,
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/ 1. F. Dale
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Manager of Nuclear Services Member Middle South Utilities System
MISSISSIPPI POWER & LIGHT COMPANY cc:
Mr. N. L. Stampley (w/o)
Mr. R. B. McGehee (w/o)
Mr. T. B. Conner (w/o)
Mr. G. B. Taylor (w/o)
Mr. Richard C. DeYoung, Director (w/a)
Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
10555 Mr. J. P. O'Reilly, Regional Administrator (w/a)
Office of Inspection & Enforcement Region II 101 Marietta Street, N.W., Suite 3100 Atlanta, Georgia 30303 AECM-82/266 Page 2
Attachment to AECM-82/262 Structural Response Due to Local Hydrogen Detonation The Grand Gulf containment shell has been evaluated for structural adequacy regarding the ability to withstand a postulated local hydrogen detonation.
The Impulsive Pressure-Time (IPT) curve associated with the local detonation was defined by Sandia National Laboratory and is presented in Figure 1 in terms of absolute pressures. This impulse will act on the containment shell in the region bounded by the suppression pool water level and the bottom of the HCU floor. Although the IPT curve in Figure 1 is shown abruptly truncated at fifteen milliseconds (msec), in reality, according to the responsible Sandia researcher, Dr. M. Sherman, the curve does extend beyond 15 msec and will eventually attenuate to atmospheric pressure. This information has been accounted for in the present evaluation by extending the IPT curve in Figure 1 with a constant pressure line beyond 15 msecs.
The response of the containment shell is evaluated by modelling it as an elasto-plastic, Single Degree of Freedom (SDOF) dynamic system and subjecting it to the given IPT curve.
The stiffness of the SDOF system is calculated based on the radial deformation of the shell assuming membrane action.
The mass of the system is calculated by equating its frequency to the breathing mode frequency of the shell. The peak static pressure at which the hoop reinforcements in the shell will yield i.s also calculated to determine the yield resistance of the SDOF system.
The minimum yield strength of the reinforcement, based on representative material test reports, has been used in the evaluation.
The SDOF system described above was analyzed for the augmented Sandia IPT curve utilizing a computer program which employs step-by-step numerical integration technique to solve the equation of dynamic equilibrium. The results of the analysis indicate that the containment shell is capable of withstanding the Sandia pressure impulse resulting from a local hydrogen detonation by mobilizing its yield resistance.
The resulting ductility ratio is calculated to be less than three, which conforms to the guidance provided in ACI 349-80, "Code Requirement for Nuclear Safety Related Concrete Structures," Appendix C.
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