ML18012A399
| ML18012A399 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 10/11/1996 |
| From: | Sheron B NRC (Affiliation Not Assigned) |
| To: | Robinson W CAROLINA POWER & LIGHT CO. |
| References | |
| TAC-M96355, NUDOCS 9610170190 | |
| Download: ML18012A399 (8) | |
Text
gAS AEG0~
~0,$,j P0 Cy
~4 ClO 10
++*++
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON) D.C. 205554001 October 11, 1996 Mr. W.
R. Robinson, Vice President Shearon Harris Nuclear Power Plant Carolina Power 8 Light Company Post Office Box 165, Mail Code:
Zone 1
New Hill, NC 27562-0165
SUBJECT:
10 CFR 50.46 LARGE BREAK LOSS-OF-COOLANT ACCIDENT EVALUATION MODEL FOR SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 (TAC NO. M96355)
Dear Mr. Robinson:
During August 1995, the Nuclear Regulatory Commission (NRC) met with Siemens Power Corporation (SPC) with regard to the large break loss-of-coolant accident (LBLOCA) evaluation model.
As a result of that meeting, we sent a
letter to SPC, dated November 13, 1995, which identified problems concerning changes in the model used by SPC for pressurized water reactors.
This model was approved by the NRC staff to meet the requirements of 10 CFR 50.46 in the letter of July 8,
- 1986, from D.M. Crutchfield (NRC) to G.
Ward (Exxon).
In the staff's letter of November 13,
- 1995, we stated that SPC had made changes to the NRC-approved Fuel Cooling Test Facility (FCTF) reflood heat transfer coefficient correlation used in the TOODEE2 computer code and did not properly assess the significance of the code changes.
It appears that the following two major changes were made to the FCTF correlation in the TOODEE2 code:
(1) some nonphysical non-monotonic behavior of the FCTF heat transfer coefficient correlation with respect to the reflood rate were eliminated and (2) the quench time calculation used in the model, using data from Cylindrical Core Test Facility (CCTF) experiments, was modified.
By letter dated March 13, 1996, the staff requested SPC to address the changes to the TOODEE2 model and the code errors identified since July 1986.
On June 2,
Revision 1, Supplement 5, which described the updates made to the TOODEE2 computer code since 1986.
The staff has completed its review of this report and has concluded that the proposed LBLOCA-ECCS model (i.e.,
1991 model) is not acceptable and the previous approved model (i.e., the 1986 model) has an unacceptable error in the model.
The staff's letter to SPC dated October ll, 1996, which includes the summary of conference calls with SPC on October 10 and ll, 1996, on this matter, will be telecopied separately.
Q~(
qhiOi70i PO, 9hiOii PDR "<<ADQCKi05000400 P 'DR NEC 8lLE GENER
~ >
'h w g y yp
,II' f
I w
'~>
)
Mr.
W.
R. Robinson DISTR IBUTION:
PUBLIC Docket Files PDII-1 r/f FMiraglia/AThadani RZimmerman SVarga MReinhart BSheron GHolahan RJones TCollins N(Tommy)
Le EMerschoff (RII)
ACRS (4)
OGC (15BIS)
October 11, 1996 Document Name:
5046.LTR'FC LPM:
R NAME JDo DATE 10 1 1 96 OFFICIAL RECORD COPY RZimmerman 10
~~
96 10
[,l 96 BShe o
10 l~ /96
C H
l'
, ~ )
I a
P
Mr. W.
R. Robinson Because of the staff's conclusions regarding the unaccepability of the reflood heat transfer coefficient correlation used in the TOODEE2 computer code, we conducted a conference call on Thursday, October 10, 1996, with several licensees, including a representative of your plant.
Other participants were representatives from Comanche Peak Station Units I/2, Kewaunee Plant, Millstone Station Unit 2, Palisades
- Plant, Robinson Plant Unit 2, St. Lucie Plant Unit 1, and SPC.
The purpose of the conference call was to inform each licensee that the staff had found changes in the unapproved 1991 LBLOCA evaluation model,. which were intended to address problems with the approved 1986 model used by SPC for the LBLOCA and emergency core cooling system
- analyses, unacceptable.
In addition, the staff indicated that it will not accept LBLOCA analyses using the previously approved 1986 model unless that model adequately corrects the non-physical behavior observed in the reflood
.heat transfer correlation.
Therefore, in accordance with 10 CFR 50.46(a)(3)(ii), you should assess the impact of these model errors and changes and take whatever actions are required to assure compliance with 10 CFR 50.46.
- Further, as you were informed in the conference call, the staff has scheduled a public meeting on October 16, 1996, at 1:00 pm, in 0-12B11, at its Headquarters Offices.
The affected plants and SPC were requested to attend this meeting to present the results of their assessment of the peak cladding temperature for the LBLOCA and the corrective actions and compensatory measures that have been undertaken, both short-term and long-term, to assure plant compliance with 10 CFR 50.46.
If you have any questions about this matter, please contact Ngoc(Tommy)
Le at 301-415-1458, or Jack Donohew at 301-415-1307.
Sincerely, Docket No. 50-400 cc:
See next page
~~ LA<
cn Brian W. Sheron, Acting Associate Director for Technical Review Office of Nuclear Reactor Regulation
Mr.
W.
R. Robinson Carolina Power 8 Light Company CC:
Mr. William D. Johnson Vice President and Senior Counsel Carolina Power 8 Light Company Post Office Box 1551
- Raleigh, North Carolina 27602 0165 Resident Inspector/Harris NPS c/o U.S. Nuclear Regulatory Commission 5421 Shearon Harris Road New Hill, North Carolina 27562-9998 Ms. Karen E.
Long Assistant Attorney General State of North Carolina Post Office Box 629
- Raleigh, North Carolina 27602 0510 Public Service Commission State of South Carolina Post Office Drawer 11649
- Columbia, South Carolina 29211 Plant Regional Administrator, Region II U.S. Nuclear Regulatory Commission 0165 101 Marietta St.,
N.W. Suite 2900 Atlanta, Georgia 30323 Mr. Dayne H. Brown, Director Division of Radiation Protection N.C. Department of Environmental Division of Radiation Protection Commerce
& Natural Resources Post Office Box 27687
- Raleigh, North Carolina 27611-7687 Mr. J.
Cowan Vice President Nuclear Services and Environmental Support Department Carolina Power 8 Light Company Post Office Box 1551 Mail OHS7
- Raleigh, North Carolina 27602 Shearon Harris Nuclear Power Plant, Unit 1
Mr., J.
W. Donahue Director of Site Operations Carolina Power 8 Light Company Shearon Harris Nuclear Power Plant Post Office Box 165, MC: Zone 1
New Hill, North Carolina 27562-Mr. Robert P. Gruber Executive Director Public Staff NCUC Post Office Box 29520
- Raleigh, North Carolina 27626 Chairman of the North Carolina Utilities Commission Post Office Box 29510
. Raleigh, North Carolina 27626-Mr. T. D. Walt
- Manager, Regulatory Affairs Carolina Power 5 Light Company Shearon Harris Nuclear Power P. 0.
Box 165, Mail Zone 1
New Hill, North Carolina 27562-Mr. Vernon Malone, Chairman Board of County Commissioners of Wake County P. 0.
Box 550
- Raleigh, North Carolina 27602 Ms.
Uva Holland, Chairman Board of County Commissioners of Chatham County P. 0.
Box 87 Pittsboro, North Carolina 27312 Mr. Milton Shymlock U.S. Nuclear Regulatory Comm.
101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323-0199
A
Hr.
Bo Clark Plant General Manager Harris Plant Carolina Power 8 Light Company Shearon Harris Nuclear Power Plant P.O.
Box 165 New Hill, North Carolina 27562-0165