ML20215K878
| ML20215K878 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 10/14/1986 |
| From: | Nerses V Office of Nuclear Reactor Regulation |
| To: | Harrison R PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| References | |
| NUDOCS 8610280347 | |
| Download: ML20215K878 (7) | |
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UNITED STATES
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hl 14 w Docket Nos.:
50-443 and 50-444 Mr. Robert J. Harrison President & Chief Executive Officer Public Service Company of New Hampshire Post Office Box 330 Manchester, New Hampshire 03105
Dear Mr. Harrison:
SUBJECT:
QUESTIONS IN REGARD TO SEABROOK UNIT I PERTAINING TO 10CFR50.55(e)
REPORT ON EMERGENCY CORE COOLING DEFICIENCY (REACTOR SYSTEMS BRANCH STANDARD REVIEW SECTIONS 5.4.7, 6.3, 15.)
REFERENCES:
1.
DeVincentis, John, " Final 10CFR50.55(e) Report:
Emergency Core Cooling System Design Deficiency (CDR-86-00-07), " letter from Public Service of New Hampshire to Richard W. Starostecki of NRC, SBN-1162, July 18, 1986.
2.
DeVincentis, John, " Emergency Core Cooling Design, " letter from Public Service of New Hampshire to Vincent S. Noonan of NRC, S8N-1178, August 19, 1986.
References 1 and 2 identify an unanticipated situation wherein insufficient head is developed at the inlet to the charging pumps when safety in.jection is occurring in the recirculation mode and one of the two RPR pumps fails. At this point, the remaining RPR pump would have been providing flow to both charging pumps (operating as safety in.iection pumps), to both safety in.iection pumps, and directly to the four RCS cold legs. NPSH requirements for the charging pumps are not met under this condition.
Your staff has proposed a solution whereby valve alignments are chanced such that the above condition would result in in.jection into only two of the RCS cold legs. Your staff has stated that this would provide sufficient head at the charging pump inlets that NPSP reauirements would be met.
We have generated a number of auestions pertaining to this issue which need to be discussed with your staff. These are provided in the enclosure. Ve suagest these questions can be the basis for a telephone conference call. The J
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conference call should provide sufficient clarification that many if not all of the questions should be satisfactorily resolved.
Questions or additional information regarding this matter should be directed to me the Seabrook Project Manager, Mr. V. Nerses (3011492-8535.
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V. Nerses, Project Manager Project Directorate No.
Division of PWR I.icensing-A
Enclosure:
As stated cc: See next page o.
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Mr. Robert J. Harrison
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Public Service Company of New Hampshire Seabrook Nuclear Power Station cc:
Thomas Dignan, Esq.
E. Tupper Kinder, Esq.
John A. Ritscher, Eso.
G. Dana Risbee, Esq.
Ropes and Gray Assistant Attorney General 225 Franklin Street Office of Attorney General Boston, Massachusetts 02110 208 State Hosue Annex Concord, New Hampshire 03301 Mr. Bruce B. Beckley, Project Manager Public Service Company of New Hampshire Resident Inspector Post Office Box 330 Seabrook Nuclear Power Station Manchester, New Hampshire 03105 c/o US Nuclear Regulatory Comission Post Office Box 700 Dr. Mauray Tye, President Sun Valley Association Seabrook, New Hampshire 03874 209 Sumer Street Mr. John DeVincentis, Director Haverhill, Massachusetts 01839 Engineering and I.icensing Robert A. Backus, Esq.
Yankee Atomic Electric Company 1671 Worchester Road O'Neil, Backus and Spielman Framingham, Massachusetts 01701 116 f.owell Street Manchester, New Fampshire 03105 Mr. A. M. Ebner, Project Manager United Engineers & Constructors William S. Jordan, III 30 South 17th Street Diane Curran Post Office Box 8223 Farmon, Weiss & Jordan Philadelphia, Pennsylvania 19101 20001 S Street, NW Suite 430 Washington, D.C.
20009 Mr. Philip Ahrens, Esq.
Assistant Attorney General State Pouse, Station #6 Augusta, Maine 04333 Carol S. Sneider, Esq.
Office of the Assistant Attorney General Environmental Protection Division Mr. Warren Pall One Ashburton Place Public Service Company of Boston, Massachusetts 0?!08 New Hampshire Post Office Fox 330 D. Pierre G. Cameron, Jr., Esq.
Seabrook, New Hampshire 03874 General Counsel Public Service Company of New Hampshire Seacoast Anti Pollution f.eague Post Office Box 330 Ms. Jane Doughty Manchester, New Hampshire 03105 5 Market Street Portsmouth, New Hampshire 03801 Regional Administrator, Region I Mr. Diana P. Randall U.S. Nuclear Regulatory Commission 631 Park Avenue 70 Collins Street King of Prussia, Pennsylvania 19406 Seabrook, New Hampshire 03874 Richard Fampe Esq.
New Hampshire Civil Defense Agency 107 Pleasant Street Concord, New Hampshire 03301
F-s Public Service Company of Seabrook Nuclear Power Station i
New Hampshire cc:
Mr. Ca' vin A. Canney, City Manager Mr. Alfred V. Sargent, City Hall Chairman 126 Daniel Street Board of-Selectmen Portsmouth, New Hampshire 03801 Town of Salisbury, MA 01950 Ms. I.etty Hett Senator Gordon J. Humphrey Town of Brentwood ATTN: Tom Burack RFD Dalton Road U.S. Senate Brentwood, New Hampshire 03833 Washington, D.C.
20510 Ms. Roberta C. Pevear Mr. Owen B. Durgin, Chairman Town of Hampton Falls, New Hampshire Durham Board of Selectmen Drinkwater Road Town of Durham Hampton Falls, New Hampshire 03844 Durham, New Hampshire 03824 Ms. Sandra Gavutis Charles Cross, Esq.
Town of Kensington, New Hampshire Shaines, Mardrigan and RDF 1 McEaschern East Kingston, New Hampshire 03827 25 Maplewood Avenue Post Office Box 366 Portsmouth, New Hampshire 03801 Chairman, Board of Selectmen RFD 2 South Hampton, New Hampshire 03827 Mr. Guy Chichester, Chaiman Rye Nuclear Intervention Mr. Angie Machiros, Chairman Committee Board of Selectmen c/o Rye Town Hall for the Town of Newbury 10 Central Road Newbury, Massachusetts 01950 Rye, New Hampshire 03870 Ms. Cashman, Chairman Jane Spector Board of Selectmen Town of Amesbury Federal Energy Regulatory Commission Town Hall 825 North Capital Street, NE Amesbury, Massachusetts 01913 Room 8105 Washington, D. C.
20426 Honorable Peter J. Matthews Mayor, City of Newburyport Mr. R. Sweeney Office of the Mayor New Hampshire Yankee Division City Hall Public Service of New Hampshire Newburyport, Massachusetts 01950 Company 7910 Woodmont Avenue Mr. Donald E. Chick, Town Manager Bethesda, Maryland 20814 Town of Exeter 10 Front Street Nr. William R. Derrickson Exeter, New Hampshire 03823 Senior Vice President Public Service Company of New Hampshire Post Office Rox 700, Route 1 Seabrook, New Hampshire 03874
1 i
ENCLOSURE Ql'ESTIONS PERTAINING TO EMERGENCY CORE COOLING DESIGN 1.
Please define the magnitude of the problem with respect to NPSH.
What is the actual head provided to the high pressure SI pumps and to the charging pumps with the deficiency uncorrected and how does this compare to the pump reouirements? What pump suction and containment sump conditions are assumed in arriving at these values and how do these compare to the conditions which exist when suction is from the RWST?
What is the actual head provided to the high pressure SI pumps and to the charging pumps with the deficiency corrected?
2.
Changes in valve alignment are described by submitting a marked un copy of portions of FSAR Figure 6.3-?.
This figure does not provide specific valve identifications, nor does it allow the staff to satisfactorily identify the valves involved due to differences in nomenclature and the schematic nature of the figure.
Please identify the valves listed in sheets 2 and 3 of the notes to Figure 6.3-P.
It would be helpful if this infonnation could be additionally provided on a marked up copy of FSAP Figure 6.2-78 in a fom that shows which valves are open and which are closed for the injection mode, the cold leg recirculation mode, and the hot leg r,ecirculation mode.
3.
If the original accident begins as an RHR line break, please describe how the response is affected by the new configuration. Please also show where this response is covered by procedures.
Include consideration of the time that pumps can operate while discharge takes place into the break and the impact of that operation upon pump operability if pump NpSH I
recuirements are not met.
4 Please contrast system perfomance as analyzed and described in the FSAR as approved by the staff, and system performance with the system modified as described in References 1 and 2.
Identify all differences.
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1 5.
If an RHR pump fails after the system has been configured to the recirculation mode, please indicate the actions that are taken by the Include reference to specific applicable procedures that are operator.
in place, timing of the operations, and times durino which pumps are operating with inadequate NPSH. Also describe the potential impact of such operation on pump operability.
6.
The proposed changes to the FSAR include addition of the words " Redund motor operated valves arranged in series are provided for this isolation function." Please identify the valves. Could these valves be required to operate under accident conditions where closure would be necessary against significant RCS pressure or under dynamic conditions associated with flow from the RCS at significant pressure?
If so, will the valve operators close the valves under the identified conditions?
If yes, what information supports valve closure reliability?
7.
Step 3 of Table 6.3-7, Sheet 1, has been changed to indicate that one valve should be closed.
Would it be better to identify a specific valve or to provide wording that more strongly indicates that both valves should not normally be closed at this time? (Note the modified Table 6.3-10 entry for times 115-145 and 145-160.) Please address accident conditions, such as accident initiation by failure of one of the injection lines at the RCS, as part of the response.
i 8.
Change over to the recirculation mode leaves two RHR pumps running, two Si pumps running, and two charoing pumps running, with all injecting into the RCS.
l What procedures exist for reduction of the number of pumps in operation and how are these affected by the changes described in References 1 and 2?
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_ s cor$ference call should provide sufficient clarification that many if not all of the questions should be satisfactorily resolved.
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Questions or additional information regarding this matter should be directed to me the Seabrook Project Manager, Mr. V. Nerses (301) 492-8535.
V. Nerses, Project Manager Project Directorate No.
Division of PWR I.icensing-A
Enclosure:
.vAs stated cc: See next page
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