ML20154K143
| ML20154K143 | |
| Person / Time | |
|---|---|
| Issue date: | 10/13/1998 |
| From: | Essig T NRC (Affiliation Not Assigned) |
| To: | Sgarro R PENNSYLVANIA POWER & LIGHT CO. |
| References | |
| PROJECT-691 NUDOCS 9810160128 | |
| Download: ML20154K143 (5) | |
Text
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f t:u i 4 UNITED STATES
, j j NUCLEAR REGULATORY COMMISSION o g WASHINGTON, D.C. 20665-0001 k o#
9.....g October 13,1998 Mr. Rocky Sgarro l Pennsylvania Power and Light i 2 North Ninth Street Mail Code A6-1 Allentown, PA 18101
SUBJECT:
CORRECTION TO PAGE B-5 OF THE STAFF'S FINAL SAFETY EVALUATION I ON GENERAL ELECTRIC TOPICAL REPORT NEDO-326896, REVISION 0,
" UTILITY RESOLUTION GUIDANCE FOR ECCS SUCT!ON STRAINER BLOCKAGE" AND CLARIFICATION OF THE STAFF'S POSITION ON EROSION l
OF CALCIUM SILICATE INSULATION '
Dear Mr. Sgarro:
1 By letter dated November 20,1996, the Boiling Water Reactor Owners group (BWROG) I transmitted General Electrlc topical report NEDO-326896, Revision 0, " Utility Resolution Guidance for ECCS Suction Strainer Blockage,"(URG) to the NRC staff for review. The staff completed its review of the URG, and issued its final safety evaluation by letter dated 1 August 20,1998.
.n a public meeting with the BWROG on September 8,1998, the staff was made aware that Page B-5 in the safety evaluation has typographical errors which could significantly impact a
- licensee's use of the URG. A corrected page is attached. Please remove Page B-5 from the staff's safety evaluation transmitted by letter dated August 20,1998, and replace it with the attached page (Enclosure 1).
During the September 8,1998, meeting, it also became clear that some licensees were confused by the wording on Page 26 of the safety evaluation regarding the erosion of calcium silicate insulation (Cal-Sil). In the first paragraph on Page 26, the staff states "The fifth affected l insulation is calcium silicate (Cal-Sil) which the staff notes should be treated as being eroded I over time by the break jet." The staff is not referring to erosion by ECCS water flow. " Break Jet," / .
in this case, refers to the blowdown phase of the accident. The staff position is that for the entire l duration of the blowdown, jet impingement from the break jet would continue to generate debris f from Cal-Sil insulation located within the zone of influence. The staff believes that the BWROG debris generation tests for Cal-Sil did not adequately demonstrate how much debris would be
!k.
generated from Cal-Sil insulation because the tests were based on short duration (approximately 5 seconds) blowdowns. Therefore, the staff concludes that the amount of Cal-Sil debris generated should be calculated by scaling the test data to the full duration of the postulated blowdovm.
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- If you have rny questions about the corrected SER page or the clarification of the staff's position concerning the erosion of calcium silicate insulation, please call Mr. Rob Elliott, at 301-415-1397.
Sincerely, l l
/A d Thomas H. Essig, Acting Chief Generic issues and Environmental Projects Branch !
Division of Reactor Program Management Office of Nuclear Reactor Regulation l
l 1
Project No. 691 l
Enclosure:
As stated cc w/ enclosure: See next page i l
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l i.
I-I J
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!* Table B-1 Results of CEESI Testing for Each Insulation Material. j Insulation Material (UD) Dest.* URG JCL' Pressures ,
Damage Estimated in l Pressure Confirmatory (psi) Analysis Darchem DARMET* 5.0 190 190 Transco RMI
- 5.0 190 190 Jacketed NUKON* with Sure-Hold
- Bands >118 190 150*
i DPSC MIRROR'with Sure-Hold
- Band 8.5 190 150*
l Calcium Silicate with Aluminum Jacketing 7 160 150*
l K-Wool 15 40 40 i
Temp-Mat with stainless steel wire retainer 30 17 17 Knaupf' 60 10 10 Jacketed NUKON* with Standard Bands >50 10 10 l Unjacketed NUKON' >60 ; < 119 10 10 l
Koolphen-K' >808 6 6 DPSC MIRROR
- with Standard Bands 99 4 4 Min-K >100* 4 <4 l
e Scalability of Results to BWR Drywells: In the CEESI experiments, a 3-inch diameter nozzle was used to simulate a broken pipe, and a 12-inch diameter pipe was used to simulate a target pipe (Reference B.2). This raises the following concems related to scalability of the experimental results:
- How can damage pressures obtained for 12-inch target pipe be used to estimate damage pressures for a smaller or a larger pipe? Since all insulation blankets are attached to pipes of different diameters by identical straps, their failure occurs at same target load irrespective of the target pipe diameter (i.e., one should look for load conservation). Therefore, the fo!!owing equation holds:
a The maximum distance at which damage or dislodgment is reported for the insulation type of interest.
The jet-center-line pressure corresponding to (t/D).,,,. The JCL pressure was extracted from the CFD results of Reference B.3.
s several different types of Transco RMI insulatsn was 'ested. However, the results presented here are for TPl 0.024-inch sheath solid end (stainless steel) with latch and strike closures. According to the URG, this insulation appears to be the most commonly
, found Transco RMIin BWRs.
- Exact number not known since testing did not go beyond the values listed for which significant damage was evident.
4 B-5 J
9 l ' 4
f a
l If you have any questions about the corrected SER page or the clarification of the staff's position !
concerning the erosion of calcium silicate insulation, please call Mr. Rob Elliott, at 301-415-1397. !
i l
Sincerely, Original Signed By: ;
Thomas H. Essig, Acting Chief Generic issues and Environmental Projects Branch Division of Reactor Program Management Office of Nuclear Reactor Regulation Project No. 691 i 1
l
Enclosure:
As stated cc w/ enclosure: See next page DISTRIBUTION:
Central Files qPublic MMarshall AScrkiz KKavanaugh JHWilson SCSB r/f (2) PGEB r/f JKudrick RElliott DSkay RArchitzel DOCUMENT NAME: bwrogecc. err T* receive e cop'r of this document, Indicate in the box: "C" a Copy without attachment / enclosure 'E' = Cop" with attachmentlenclosure 'N' - No copy OFFICE PGEB:DRPl/ , _ [6 PGEB:DRPM _ g BC:SCSB:DJEAff l BC:PGEB:QRPM l l NAME JHWilson Y@ RArchitzel IV CBerlingel#/3 TEssig / , A6s DATE 10/7 /98 / 10y /98 10 //y,/98 10/(.i38 " 8 OFFICIAL RECORD COPY l
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le l ..-
I Project No. 691 l Boiling Water Reactor Owners Group l
cc: Thomas J. Rausch, Chairman W. Glenn Warren Boiling Water Reactor Owners' Group Southem Nuclear / Georgia Power l Commonwealth Edison Company E.1. Hatch Nuclear Plant l Nuclear Fuel Services PO Box 1295 M/C B052 1400 Opus Place,4th Floor ETWill Birmingham, AL 35201 Downers Grove,IL 60515 Carl D. Terry Dennis B. Tcwnsend Vice President, Nuclear Engineering GE Nuclear Energy Niagara Mohawk Power Corporation M/C 182 Nine Mile Point-2 175 Curtner Avenue PO Box 63 San Jose, CA 95125 l Lycoming, NY 13093 l
l Drew B. Fetters Thomas A. Green PECO Energy GE Nuclear Energy Nuclear Group Headquarters Mail Code 182 l MC 62C-3 175 Curtner Avenue j' 965 Chesterbrook Blvd. San Jose, CA 95125 l Wayne, PA 19087 l
John Hosmer Commonwealth Edison l Executive Towers,4th Floor l 1400 Opus Place Downers Grove,IL 60515
[
i George T. Jones Pennsylvania Power & Light MC A6-1
- Two North Ninth Street Allentown, PA 18101 Lewis H. Sumner Southem Nuclear / Georgia Power E.1. Hatch Nuclear Power Plant 40 invemess Parkway i PO Box 1295 Birmingham,GA 35201 L
l John Kelly New York Power Authority 14th Floor Mail Stop 14K Centroplex Building 123 Main Street White Plains, NY 10601 4
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