ML19318C689
| ML19318C689 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 10/31/1979 |
| From: | Hood D Office of Nuclear Reactor Regulation |
| To: | Rubenstein L Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19318C683 | List: |
| References | |
| TASK-AS, TASK-BN-79-42 BN--79-42, BN-79-42, NUDOCS 8007020167 | |
| Download: ML19318C689 (1) | |
Text
{D"
/
UNITED STATES f
i NUCLEAR REGULA TORY COMMISSION
- C WASHINGTC fl. D. C. 20555 o,
a
(
%,**"*/
')CT :: ! 1979 l-MEMORANDUM FOR:
L. S. Rubenstein, Acting Chief, Light Water Reactors Branch No. 4, DPM FROM:
Darl Hood, Project Manager, Light Water Reactors Branch No. 4, DPM
SUBJECT:
TELECON FOR NOTIFICATION ON SUMP SCREEN DEFICIENCY
REFERENCE:
" Summary of Trip to Observe Nidland Sump Tests" dated 9/17/79 On 10/31/79 at 8:45 am I received a call from Messrs. Mike Salerno and Jim Zabritski of Consumers Power Company regarding the referenced trip sumary of a staff visit to observe a containment sump test. The call was with regard to our requirement stated in the trip report that the B&W concern regarding core blockage must be further explained and evaluated, Mr. Zabritski advised that our concern had been forwarded to B&W for resolution.
Mr. Salerno confirmed that the requirement for a fine mesh (0.04 inch) sump screen results from a B&W concern resulting from trapping of fine particles (e.g., foam glass insulation) between the fuel spacer grid and fuel elements which is postulated to continue during the post-LOCA recirculation code until fuel blockage in excess of that used in Appendix X analyses results. The addition of the fine screen in the Midland design results from the applicant's inability to verify that such a significant extent of blockage could not other-wise occur.
The concern was recognized to be generic to other PWR plants in addition to Midland. Messrs. Salerno and Zabritski were not aware of why other B&W plants did not have similar screens in response to the B&W concern.
The concern brings into question the conservativeness of LOCA analyses and assumptions. A prompt review should be performed to determine whether ASLB notifications are in order.
,1/sni /b o Darl Hood, Pro ect Manager Light Water Reactors Branch No. 4
{
Division of Project Management cc:
R. Mattson D. Vassallo V. Stello
{
S. Hanauer S. Varga
- 11. Thornburg l
T. Speis M. Williams D. Ross T. Novak J. Watt D. Eisenhut 1
1 1
s o oy op 0W7
...