ML17037B939
| ML17037B939 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 12/29/1976 |
| From: | Rhode G Niagara Mohawk Power Corp |
| To: | Rusche B Office of Nuclear Reactor Regulation |
| References | |
| Download: ML17037B939 (6) | |
Text
NRC FORM 195 U.S, NUCLEAR REGULATORV COMMISSION I2.28)
NRC DISTRIBUTION Fo ART 50 DOCKET MATERIAL.
DOCKET NUMBER 50-410 PILE NUMBER
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Mr. jenard C. Rusche FROM:
Niagara Mohawk Power Corp.
- Syracuse, New York Mr. Gerald K. Rhode DATE OF DOCUMENT 12/29/76 DATE RECEIVED 1/3/77
@LETTER g ORIG INAL CICOPv DESCRIPTION CINOTO R IZ E 0
. PfUNC LASS I F I E D PROP INPUT FORM
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ENCLOSURE
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NUMBER OF COPIES RECEIVED One'signed Ltr. re our 6/25/76 ltr.. and G;E.'s 9/30/76
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and 12/21/76 l.trs....concerning Anticipated Transients'ithout Scrgpm.
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I fKCK+P~EDGjPD PLANT NAMEi
~ Nine Mile'Point 82 iQQ N6T REMOVE I
SAFETY
'SSIGNED AD:
o R
CT MANA E L C ASST Var a Service FOR ACTION/INFORMATION PROJECT MANAGER LIC ASST 1677 RJL REG FILE NR~D X&E OELD GOSSICK & STAFF MIPC CASE HANAUER HARLESS PROJECT MANAGEMENT BOYD Pa COLLINS HOUSTON PETERSON HELTEMES SKOVHOLT LPDR Oswe o
N..Y.
TIC:
NSXC:
ASLB:
-CYS 4HRKIX4C/
INTERNALD SYSTEMS SAFETY HEINEMAN SCHROEDER ENGINEERING KNIGHT SIHWEXL PAWLICKI REACTOR SAFE ROSS ~o NOVAK ROSZTOCZY CHECK AT&I SALTZMAN RUTBERG EXTERNALDISTRIBUTION NAT LAB REG V.IE LA PDR CONSULTANTS ISTRl BUTION PLANT SYSTEMS TEDESCO N
IPPOLXTO OPERATING REACTORS STELLO OPERATING TECH EISENHUT B
E ULRIKSON OR SITE SAFE ERNST BALLARD SPANGL SITE TECH GAMIILL STEPP HULMAN SITE ANALYSIS VOLLMER BUNCH J ~ COLLINS KREGER CONTROL NUI%1BER NRC FORM 106 {2-78)
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NIAGARA MOHAWK POWER CORPORATION NIAGARA MOHAWK 300 ERIE 60ULEVARD WEST SYRACUSE, N.Y. ISZOE December 29, 1976 Mr. Benard C. Rusche, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555 JAN3 SP~-
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Rl@SQQO IN q
Re:
Nine Mile Point Unit 2 Docket No. 50-410
Dear Mr. Rusche:
Zn response to Mr. R. Boyd's letter of tune 25, 1976, Niagara Mohawk Power Corporation proposes to resolve the issue of Anticipated Transients Without Scram by installation of an Alternate Reactor Scram System at Nine Mile Point Unit 2.
The General Electric "BWR Scram System Reliability Analysis Report" dated September 30, 1976, provides a detailed description of the Alternate Reactor Scram System equipment and testing program.
The Nuclear Regulatory Commission criterion for resolution of this concern requires a demonstration that" the scram syst'm reliability is'such that the probability of failure to scram is approximately 10 per year.
The Alternate Reactor Scram System provides diverse and redundant hardware for those portions of the scram system where the most significant contribution to reliability can be achieved.
Incorporation of an Alternate Reactor Scram System reduces 'the probability'f failure to scram to approximately 4 x 10-8'per year.
In addition, modification of the scram system provides optimum protection from common mode failures.
As indicated by the December 21, 1976 General Electric letter to the Nuclear Regulatory COmmission, resolution of Anticipated Transients Without Scram by mitigation would require an expenditure of approximately 5'28,000,000 per plant.
This estimate does not include increased fuel costs and other allowances for funds during construction which may be attributable to delays in plant operation.
Conversely, t'e cost for implementation of the Alternate Reactor Scram System is expected to be less than
$500,000 per plant.
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2 In summary, we believe that acceptable reliability can be demonstrated by installation of an Alternate Reactor Scram System and that mitigating systems are unnecessary.
We concur with the Nuclear Regulatory Commission in it's desire to resolve the Anticipated Transients Without Scram as soon as practical, and we remain available to discuss ouz proposal for resolution.
Upon receipt of your concurrence with our proposal, we will proceed with the detailed design and implementation necessary to ensure the required scram reliability.
Si ncerel y, NIAGARA MOHAWK POWER CORPORATION t
GERA D K.
HODE Vice Pzesi dent Engineering WRD/sz