ML20204G824
| ML20204G824 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 10/18/1988 |
| From: | Wang A Office of Nuclear Reactor Regulation |
| To: | Mroczka E CONNECTICUT YANKEE ATOMIC POWER CO. |
| Shared Package | |
| ML20204G826 | List: |
| References | |
| TAC-61990, NUDOCS 8810240243 | |
| Download: ML20204G824 (3) | |
Text
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- Cocket No. 50-213 DISTRIBUTION Chtre W AWang
. Mr. Edward J. Nroczka NRC & Local PORs OGC Senior Vice President Gray File EJordan Nuclear Engineering and Operations SYarga BGrimes l
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Connecticut Yankee Atomic Power Company BBoger (ACRS(k6i'.bkR l
Post Office Box 270 SNorris DOC
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Hartford, Connecticut 06141 - 0270
Dear Mr. Mroczka:
SUBJECT:
SAFETY EVALUATION OF NORTHEAST UTILITIES' TOPICAL REPORT l
151, "HADDAM NECK NON-LOCA TRANSIENT ANALYSIS" l
By letter dated June 30, 1986 Northeast Utilities Service Company (NUSCO),on behalf of Conrecticut Yankee Atomic Power Company (CYAPCO), submitted Topical i
Report NUSCO-151, "Haddam Neck Plant Non-LOCA Transient Analysis" for staff j
review and approval. As part of the Systematic Evaluation Program (SEP),
i CYAPC0 proposed to perform a conprehensive rcanalysis of design-basis events
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(DBE). The SEP review also concluded that the 12 DBEs described in Chapter 10 i
of the Facility Cescription and Safety Analysis (FDSA) with the addition of the Reactor Coolant Pump (RCP) rotor seizure / shaft break events constitutes a cceplete and consistent set of design basis events. The reanalysis was j
perfomed to demonstrate the licensee's ability to perfonn in-house safety analysis, to better understand the plant-specific resyonse to DBEs and to provide an updated set of design basis aralysis for tie Haddam Neck Plant.
l NUSCO-151 provides this reanalysis, i
As part of the Cycle 10 reload review, the staf.' has reviewed and a) proved Five of the 13 events separately. They are 1) Uncontrolled rod withdraw,
- 2) Boron dilution, 3) Rod Cluster Control Assembly (PCCA) ejection including radiological consequences, 4) Dropped rod and 5) Loss of flow.
The remaining events reviewed in this report are 1) Isolated loop startup 2) Excess i
feedwater, 3) Steamline rupture, 4) Steam generator tube rupture including
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radiological consequences, 5 Excessive load increase, 6) Loss of load, 7)
Loss of feedwater flow and 8 RCP rotor seizure / shaft break.
The staff has completed its review and finds, with the exception of the excess feedwater event, that the results of the analyses perforned meet the acceptance criteria for each event according to the Standard Review Plan (SRP). While the staff finds that the analysis of the excess feedwater event does not satisfy the SRP because of the limited operator response tirne, the analysis does meet a
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the original design basis. The reanalysis rneets the original design basis even i
with the nore conservative assumption that one feedwater regulating valve failed rather than all four. This assumption increeses feedwater flow through the failed valve as corpared to the original design analysis assurption.
The excess feedwater e/ent is initiated by a failure of a main feedwater regulating i
i valve. This failure can be initiated either by an instrunent or mechanical failure of the valve.
Instrurent failure of the main feedwater regulating valves is being addressed by Integrated Safety Assessment Program j
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GG10240243 881018 f
DR ADOCK 0500 3
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t (ISAP) Topic 1.54, "Safety Implications of Control Systems (USIA-47)".
As discussed with your staff, ISAP Topic 1.54 should be expanded to include an ar.alysis for n;echanical failure of the main feedwater regulating valves. As conriitted to in SEP, the reanalysis of the excess feedwater event should "denenstrate that the operator would have arrple tine to diagnose and mitioate the transient, derronstrate that the consequences of this event are acceptable or develop corrective actions as necessary."
In addition, we are currently reviewing ycur rtTctor protection system upgrade.
If we find any significant change in the instrument response times assun.ed in the topical, the NRC staff will require a reanalysis of the affected event (s).
A copy of our related Safety Evaluation is enclosed.
This completes all staff review of this topical.
In addition, the staff now considers SEP Topics XV-1,"Decrease in Feedwater Temperature, Increase in Feedwater Flow, Increase in Steam Flow, and Inadvertent Opening of a Steam Generator Pelief or Safety Valve", XV-7,"Loss of Forced Coolant flow, Reactor Coolant Punip Rotor Seizure, and Reactor Coolant Pump Shaft Break", XV-12,"Radiological Consequences of a Red Ejection Accident", and Topic XV-17,"Steam Generator Tube Rupture" c on>pl e te. The two remaining open itens from these SEP Topics operator timing for the excess feedwater event and adopting STS limits for primary and secondary coolant iodine concentrations will be resolved in the ISAP and the conversion to Standard-Fomat Technical Specifications (STS) programrespectively.
Sincerely, orig 1nalsignedby Alan B. Wang, Project Panager Project Directorate I-4 Division of Reactor Projects I/II
Enclosure:
As stated cc w/ enclosure See next page L&:f$1-4 PM:PDI-4 D:PDI-4 Sf2frfs D.Vatze Awanf U (tolg f
M/l4/88 M/,1/88 09/W/88
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l Mr. Edward J. Kroczka t
Connecticut Yankee Atomic Power Company Haddam Neck Plant cc:
i Gerald Garfield, Esquire R. N. Kacich, Manager Day, Berry and Howard Generation Facilities Licensing Counselors at Law Northeast Utilities Service Company i
City Place Post Office Box 270 Hartford, Connecticut 06103-3499 Hartford, Connecticut 06141-0270 I
W. D. Romberg, Vice President D. O. Nordquist Nuclear Operations Manager of Quality Assurance Northeast Utilities Service Company Northeast Nuclear Energy Cortpany Post Office Box 270 Post Office Box 270 Hartford, Connecticut 06141-0270 Hartford, Connecticut 06141-0270 Kevin McCarthy, Director Regional Administrator R&diation Control Unit Region !
Departrent of Environmental Protection U. S. Nuclear Regulatory Conrission State Office Building 475 Allendale Road Hartford, Connecticut 06106 King of Prussia, Pennsylvania 19406 Bradford S. Chase, Under Secretary Board of Selectmen Energy Divisicn Town Hall Office of Policy and Managerent Haddam, Connecticut 06103 80 Washington Street Hartford, Connecticut 06106 J. T. Shedlosky, Resider,t Inspector Haddam Neck Plant D. B. Miller, Station Superintendent c/o V. S. Nuclear Regulatory Comission Haddam Neck Plant Post Office Box 116 Connecticut Yankee Atomic Power Company East Haddam Post Office RFD 1. Post Office Box 127E East Haddam, Connecticut 06423 East Hampton, Connecticut 06424 G. H. Bouchard, Unit Superintendent Haddam Neck Plant RFD fl 4
Post Office Box 127E East Harpton, Connecticut 06424
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