ML20202G277
| ML20202G277 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 04/16/1986 |
| From: | Schrock V CALIFORNIA, UNIV. OF, BERKELEY, CA, Advisory Committee on Reactor Safeguards |
| To: | Ward D Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1843, NUDOCS 8607150355 | |
| Download: ML20202G277 (2) | |
Text
.. g UNIVERSITY OF CALIFORNIA, BERKELEY EEAKELEY
- Davis
- IRvDIE
- 14$ ANCELES
- RIVERSIDE
- SAN DIECO
- SAN FRANOSCO SANTA mann4. SANTA SUE cou.EcE or ENczNzzarNo samazLsy, CALIFORNIA 94720 DEPARTMENT OF NUCLEAR ENGINEERING Mr. David Ward. Chairman April 16, 1986 DHRS/ECCS Subcommittees U.S.
Nuclaer Regulatory Commission Advisory Committee on Reactor Safeguards L..............,....,
iN Dear Dave.
Subject:
Comments of the March 26, 1986 Meeting 1.
Duke Power Company request to delete the UHI ECCS at McGuire The UHI system has caused operational complications and problems and is responsible f or significant dose to plant personnel during refueling.
In addition it has potential for initiating a small break LOCA and for injecting nitrogen into the primary system if it is actuated and the block valve fails to close.
These negative features of the system have to be weighed against its positive contribution in mitigating the consequences of accident secequences.
The calculations and arguments presented by Duke and Westinghouse fell far short of weighing these factors.
They made the point on several occasions that "we are smarter now than we were ten years ago" however this fact was not evident from their low quality presentations.
The staff view that they are required to allow removal of the system if in their view it has been shown that the plants will still meet the regulations is undoubtedly legally correct but it does not show that they are using the greater wisdom they have gained in the last ten years.
In the end I suspect that Glenn Reed's assessment of the situation may be right: the negative features outweigh the positive attributes of the UHI and its removal is justified.
What conc'er69 me is that there was not an honest attempt made to show that this is the case.
I have the impression that the staff approach in this may have been influenced by current budgetary pressures.
I view this case as one of declining quality of the dialogue between utilities / vendors, the regulatory staff and ACRS.
It is a trend that should be of concern to the ACRS.
I)ESIO:!ATED 031GIIIAL j
Cortified By
2.
Generic Issue 124 I found the acceptable reliability to be too vague.
If this is i
stated as a range (10'#- 10'# failures / demand) the.. higher figure would have to be accepted.
Also it seems to me that the ultimate risk may not be the same f or all plants f or the same level of AFW reliability.
Si cerely, ff h' $.
--'^'
V Vgil E. Schrock Professor y.-- - _.-
_.