ML20003C993
| ML20003C993 | |
| Person / Time | |
|---|---|
| Issue date: | 06/27/1980 |
| From: | Tong L NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | |
| Shared Package | |
| ML20003C956 | List: |
| References | |
| NUDOCS 8103181022 | |
| Download: ML20003C993 (1) | |
Text
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O NRC's Needs on LWR Safety Codes L. S. Tong (Presented at the. joint meeting of the Advanced Code Review Group and.the Code Assessment Review Group et Silver Spring, June 26-27, 1980)
Thank you for coming here to help us in the development and assessment of water reactor safety codes to meet the NRC's needs.
1.
We need reliable best-estimate comuter codes available for predicting the system response of anomalous transients or accidents in either PWRs or SWRs. To meet this need, adequate codes cust be kept in operational condition. Adnittedly, existing codes may ceed improvement,.but the calculation tools must be available now, even with tentative remedies and approximations included, to me::t the emergency needs at any time. These remedies and approximations shculd be reported to the NRC and Review Groups in advance for review and coment on their adequacy.
2.
In code improvement, the key physical chenomen in the ancnalous transients and postulated accidents must be orcoerly modeled to produce meanitigful results. We cannot accept any coce results if physical phenomena is ill-modeled or not even considered in the code, despite fortuitous agreement with data.
3.
In code assessment, the modeling of all important physical phenomena should be reported to the NRC and Review Groups for assessment.
Then to better understand the physics, a system code should be assessed by comparing sacarately the code hydraulic parameters and the peak clad temperature parameters with corresponding data.
4.
The usefulness of a code is strcngly affected by its running time.
The tem " code running time" apolies only to the codes that run continuously through the entire transient without interruptions for mid-stream code fixings. In the future, analyses may be used *4 predict the system response for selecting the viable countermeasures during an accident. Therefore, improvement of ntceries of ex. sting codes is also an important task for which your experience and advice are highly appreciated.
Thank you.
8103181022
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