ML003676899
| ML003676899 | |
| Person / Time | |
|---|---|
| Issue date: | 01/24/2000 |
| From: | Marshall M Office of Nuclear Regulatory Research |
| To: | Modeen D Nuclear Energy Institute |
| References | |
| Download: ML003676899 (2) | |
Text
January 24, 2000 Nuclear Energy Institute 1776 I Street, NW Suite 400 Washington, DC 20006-3708
SUBJECT:
CONFIRMATION OF SELECTED SUMP DESIGN SURVEY RESPONSES
REFERENCES:
(1) Modeen, D. (NEI), Letter to Marshall, M. (NRC),
Subject:
Additional Sump Design Survey Results and Feedback on NRC Sump Research Program, Date: September 30, 1999.
(2) Modeen, D. (NEI), Letter to Hannon, J. (NRC),
Subject:
Results of Survey Conducted on Pressurized Water Containments and Recirculation Sumps, Date: June 9, 1999.
Dear Mr. Modeen:
Thank you for coordinating the collection of responses to the pressurized water reactors sump design survey (References 1 and 2). As we have stated at several public meetings concerning the ongoing PWR sump blockage study, both the NRC and LANL staff have found the information that NEI has collected extremely useful.
We have completed our review of the survey responses. We believe some of the responses given by plants may be inaccurate. During one of the public meetings, Mr. Kurt Cozens of your staff offered to confirm the accuracy of survey responses that we believe may be inaccurate. Enclosed is a list of responses that are questionable.
If you have any questions regarding the enclosed list or would like to arrange a telephone conference to discuss the enclosed list, please, contact me at 301-415-5895 (phone), 301-415-5151 (fax), or mxm2@nrc.gov (email). We appreciate the support that your organization and the PWR owners groups have provided and look forward to a continuing cooperative working relationship.
Cordially, Michael L. Marshall, Jr.
Project Manager and Mechanical Engineer
Enclosures:
(1)
List of Questionable Responses to Sump Design Survey CC:
J. Hannon, NRC R. Elliott, NRC D. Rao, LANL K. Cozens, NEI List of Questionable Responses to Sump Design Survey Plant
Response
Comments Following a LBLOCA, when does the low pressure safety injection (LPSI), residual heat removal (RHR), and/or recirculating pumps start to draw suction from the sump? {sec}
1 Calvert Cliffs 1 480 minutes This seems like too much time.
2 Calvert Cliffs 2 480 minutes 3
San Onofre 2 0.33 minutes This seems like too little time.
Following a LBLOCA, when is the maximum containment flood level reached? {sec.}
4 San Onofre 2 0.5 minutes This seems like too little time.
How much trash rack is available? {ft. sq.}
5 St. Lucie 2 883 ft2 It appears credit is being taken for gates and other obstacles that are not local to the sump.
What is the hole size in the trash rack? {inches}
6 Salem 1 0.23 in2 This seems too small.
7 Salem 2 0.23 in2 Does the sump have a debris curb? What is the height of the debris curb? {ft}
8 ANO-2 No Response Any solid obstruction at the containment floor level, in front of, or under the sump screen can be considered a curb. A good example of this would be the angle iron or channel used to fasten the screens to the floor.
9 Davis-Besse No Response 10 Fort Calhoun No Response 11 Indian Point 2 No Response 12 Indian Point 3 No Response 13 Farley 1 and 2 No Response 14 North Anna 1 No Response 15 Nrth Anna 2 No Response 16 Pt. Beach 1&2 No Response 17 Surry 1 &2 No Response Approach Velocity (Not a Survey Question) 18 Vogtle 12 ft/s*
Based on screen area reported in survey and pump flow rates reported in
, LANL staff calculated an approach velocity for each plant. Some of the calculated values seem too high or too low.
- Calculated by LANL.
19 Indian Point 3 1.4 ft/s*
20 Callaway 0.05 ft/s*
How Much Screen Area is Available?
21 Vogtle 5.84 ft2 Screen area reported in the survey seem too high or too low.
22 St. Lucie 2 571 ft2 23 Callaway 692 ft2