ML20039C009
| ML20039C009 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 12/23/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| References | |
| TASK-04-02, TASK-4-2, TASK-RR LSO5-81-12-077, LSO5-81-12-77, NUDOCS 8112280305 | |
| Download: ML20039C009 (8) | |
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k December 23, 1981 Docket No. 50.213 g
LS05-81-12-077
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If Mr. W. G. Counsil, Vice President a
Nuclear Engineering and Operations
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ffffj Connecticut Yankee Atomic Power Company N
/84 Pc:t Office Box 270' V
Hartford, Connecticut 06101 I
Dear Mr. Counsil:
SUBJECT:
SEP TOPIC IV-2. REACTIVITY CONTROL SYSTEMS DRAFT SAFETY EVALUATION - HADDAM NECK NUCLEAR POWER PLANT
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Enclosed is a copy of our draft safety evaluation of SEP Topic IV-2, Reautivity Control Systems for Haddam Neck. This assessment compares your facility, as described in Docket No. 50-213, with the criteria currently used by the regulatory staff for licensing new facilities.
Please inform us if your es-built facility differs from the licensing basis assumed in our assessment.
Your response within 30 days of the date you receive this letter is re-r quested.
If no response is received within that time, we will assume that you have no coments or corrections. This evaluation should be a basic input to the evaluation of Topic XV-8 and the integrated safety.
assessment for your facility unless you identify changes needed to reflect the as-built conditions at your facility. This assessment may be revised in the future if your facility design is changed or, if HRC criteria relating to this subject are modified before the integrated assessm nt is completed.
Sincerely, 1
e112280305 811223y Dennis M. Crutchfield, Chief PDR ADOCK 05000213 Operating Reactors Branch No. 5 P
PDR Division of Licensing
Enclosure:
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Docket No. 50-213 LS05 12-077 Mr. W. G. Counsil, Vice President Nuclear Engineering and Operations Cor1ecticut Yankee Atomic Power Company Pos? Office Box 270 Hartford, Ccnnecticut 06101
Dear Mr. Counsil:
SUBJECT:
SEP TOPIC IV-2, REACTIVITY CONTROL SYSTEMS DRAFT SAFETY EVALUATION - HADDAM NECK NUCLEAR POWER PLANT Enclosed is a copy of our draft safety evaluation of SEP Topic IV-2, Reactivity Control Systems for Haddam Neck.
This assessment compares your facility, as described in Docket No. 50-213, with the criteria currently used by the regulatory staff for liceraing new facilities.
Please inform us if your as-built facility dif4rs from the licensing basis assumed in our assessment.
Your respcnse within 30 days of the date you receive this letter is re-quested.
If no response is received within that time, we will assume that you have no comments or corrections.
This evaluation should be a basic input to the evaluation of Topic XV-8 and the integrated safety assessment for your facility unless you identify changes needed to reflect the as-built conditions at your facility.
This assessment may be revised in the future if your facility design is changed or, if NRC criteria relating to this subject are raodified before the integrated assessment is completed, Sincerely, Dennis M. Crutchfield, Chief j
Operating Reactors Branch No. 5 6
Division of Licensing
Enclosure:
As stated cc w/ enclosure:
See next page
o Mr. W. G. Counsil I
CC Day, Berry & Howard Counselors at Law One Constitution Plaza Hartford, Connecticut 06103 Superintendent Haddam Neck Plant RFD #1 Post Office Box 127E East Hampton, Connecticut 06424 Mr. Richard R. Laudenat Manager, Generation Facilities Licensing Northeast Utilities Service Company P. O. Box 270 Hartford, Connecticut 06101 Russell Library 119 Broad Street Middletown, Connecticut 06457 Board of Selectmen Town Hall Haddam, Connecticut 06103 Connecticut Energy Agency ATTN: Assistant Director Research and Policy Development Department of Planning and Energy Policy 20 Grand Street l
, Hartford, Connecticut 06106 I
U. S. Environmental Protection Agency l
Regior. I Office ATTN: Regional Radiation Representative l
JFK Federal Building l
Boston, Massachusetts 02203
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Resident Inspector Haddam keck Nuclear Power Station c/o 0. S. NRC East Haddam Post Office East Haddam, Connecticut 064?.3 o
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SAFETY EVALUATION REPORT SEP TOPIC IV-2, REACTIVITY CONTROL SYSTEMS INCLUDING FUNCTIONAL DESIGN AND PROTECTION AGAINST SINGLE FAILURES HADDAM NECK NUCLEAR POWER PLANT DOCKET NO. 50-213
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INTRODbCTION The purp,ose of this evaluation is to insure that the design basis.for the Haddag,Nec'k reactivity control systems is con-analy'es performed to verify that the protection sistent with s
system meets General Design Criterion 25.
General Design Criterion 25 requires that the reactor protection system be designed to assure that specified acceptable fuel design limits are n ot exceeded for any single calfunction of the reactivity control systemse such as accidental withdradat of control rods.
Reactivity control systems need not be single failure proof.
Howevere the protection system must be capable of assuring that acceptable fuel design limits are not exceeded in the event of a single failure'in the reactivity control systems.
The rcview c r i t e r'i on e covered in this evaluation-is address-
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ed in Section II.
Review areas that are not coverede but are related and essential to the completion of this topice are 4
j covered-by other SEP t opics addressed in Section III.
The scope of the SEP topics is defined in the " Rep.. t on the Systematic Evaluation of Operating, Facilities" dated November 25, 1977.
This report is limited to.the identification of inadvertent con-trol rod withdrawals and malpositioning of controls rods which may occur as a result.of single failures in the control rod drive system.
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II.
REVIEW CRITERION
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The review criterion f'or this topic is based upon Section,7.7e Part II of the NRC Standard Review Plan.
In the specific case of the reactivity control systems a single failure shall 'ot n
cause plant conditions more severe than those for which the reactor protection system is designed.
III.
RELATED SAFETY TOPICS The following listed review areas are not covered in this reporte but are related and essential to the c oi.'p l e t i on of this topic.
These review arees are covered by other SEP topics as indicated below.
1.
Analyses of the consequences of control; rod withdrawals 'and 5
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the malpositioning of control rods which may occur as a re-sult of single failures in the electrical circuits of the reactivity control systems are govered by SEP Topic XV-8,
" Control Rod Misoperation (System Malfunction or Operator E r r o r " '<.
- 2. Analy,es of reactivity insertions occurring as a result of inadve rt ent boron dilutions are covered in SEP Topic XV-10,
" Chemical and Volume Control System Malfunction tnat Results in a Decrease in Boron Concentration in the Reactor Coolant".
N, IV.
REVIEW GUIDELINES The purpose of this evaluation is to identify inadvertent con-trol rod withdrawals and malpositivi.ing of control rods which r.a y occur as a result of single failure in the control rod drive system for the Haddae Neck Nuclear Power Plant.
V.
EV"LUATION Information was provided in Connecticut Yank'e Atomic Power Cenpany letter dated May 18, 1981, describing single failures within the control rod drive system which can cause control rod withdrawals
..n d malpositioning of control rods at the M ddam Neck Nuclear Power Plant.
Also included was a des-cription of design features which limit reactivity insertion
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rates and rod malpositionings resulting from single failures.
Based upon an audit review of the information provided by the licensee we conclude that the following may occur as a result of single failures:
1)
Two banks of shutdown or control rods may move simultan-eously instead of one bank.
2)
Two subgroups of control rods could move simultaneously 70 instead of one subgroup.
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3)
A clustere s ub g(o u p / o r bank of shutdown rods may not move when movement is commanded.
4)
A clusteri clusterse subgroupe banke or banks of con-trol rods may not move when movement is commanded.
5)
One bank of shutdown rods could move inadvertently.
6)
A subgroupe bank or banks (in overlap region) of control rods could move in ad ve r t en t ly.
7)
An individual shutdown rod or a clustere subgroupe bank or banks of shutdown rods could fall into the core.
1 8)
An individual control rod or clustere clusterse subgroupe bank or banks of control rods could fall into the core.
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This conclusion is based upon the design of the control rod drive system.
It should be noted that the licensees in his L e.t t e r s states that item 1 above could not be caused by a single failure.
Also the above items are more encompassing as to the grouping of rods affected by single failures.
VI.
CONCLUSION The eight types of events listed above should be' considered in the evaluation of SEP Topic XV-8.
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