ML20041C123

Forwards Final Safety Evaluation of SEP Topic IV-2, Reactivity Control Sys

ML20041C123
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	02/22/1982
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 LSO5-82-02-096, LSO5-82-2-96, NUDOCS 8202260232
Download: ML20041C123 (7)

Text

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w February 22, 1982 A

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Docket No. 50-213 L505-82 096 qs '

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Mr. W. G. Counsil Vice President I

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Nuclear Engineering and Operations Connecticut Yankee Atomic Power Company Post Office Box 270 13 4

Hartford, Connecticut 06101

SUBJECT:

SEP TOPIC IV-2, REACTIVITY CONTROL SYSTEMS DRAFT SAFETY EVALUATION - HADDAM NECK NUCLEAR POWER PLANT Enclosed is a copy of our final 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 licensing new facilities and has been revised to reflect your February 3,1981 letter.

This evaluation will be a basic input to the evaluation of Topic XV-8 and the integrated safety assessment for your facility. This assess-ment may be revised in the future if your ficility design is changed or modified before the integrated assessment is completed.

Sincerely, Dennis M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing

Enclosure:

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Mr. W. G. Counsil j

cc Day, Berry & Howard Counselors at Law One Constitution Plaza Hartford, Connecticut 06103 Superintendent Haddam Neck Plant RF0 #1' Post Office B)x 127E Ecst 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 State of Connecticut Office of Policy and Management ATTN: Under Secretary Energy Division 80 Washington Street Hartford, Connecticut 06115 U. S. Environmental Protection Agency Region 1 Office i

' ATTN: Regional Radiation Representative l

JFK Federal Building Boston, Massachusetts 02203 Resident Inspector Haddam Neck Nuclear Power Station c/o U. S. NRC l

East Haddam Post Office East Haddam, Connecticut 06423 L

Ronald C. Haynes, Regional Administrator l

Nuclear Regulatory Commission, Region I Office of Inspection *and Enforcement 631 Park Avenue f

King of Prussia, Pennsylvania 19406 l

SAFETY EVALUATION REPORT SEP TOPIC'[V-2, REACTIVITY CONTROL SYSTEMS INCLUDING FUNCTIONAL DESIGN AND PROTECTION AGAINST SINGLE FAILURES HADDAM NECK NUCLEAR POWER PLANT DOCKET NO. 50-213 I.

INTRODUCTION The purp,ose of this evaluation is to insure that the design basis for the H a d d ag, N e c'k reactivity ' control systems is con-

,sistent with analy'ses performed to verify that the protection system meets General Design Criterion 25.

General Design Criterion 25 requires that the reactor protection system-be des,igned to assure that specified acceptable feel design limits are not exceeded for any single malfunction of the reactivity control systems, such as accidental withdrawal of control rods.

Reactivity control systems need not be single failure pro'ef.

Howevere the protection system must be capable of assuring l

that acceptable fuel design limits are not' exceeded in the event of a single failure in the reactivity control systems.

l The review criterione covered in this evaluatione is addres's-ed in Section II.

Review areas that are not coverede but are related and essential to the completion of'this topice are

covered by other SEP topics addressed in Section III.

The scope of the SEP topics is defined'in'the " Report on the Systematic Evaluation of Operating, Facilities" dated November 25, 1977.

This report is l'imited 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 The review criterion for this topic is based upon Section 7.7, Part II of the NRC Standard Review Plan.

In the specific case

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of the reactivity control systems a single failure shall not 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 ct.pletion of this topic.

fhese review arees are covered by other SEP topics as indicated below.

1.

Analyses of the consequences of control rod withdrawals 'and L

t h e m'a l p o s'i t i on i n g 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 Error").

.2. Analyses of reactivity insertions o c c u r r in g as a result of inadvertent boron dilutions are overed in SEP Topic XV-10e "Ch'emical and Volume Control System Malfunction that Results

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in a, Decrease in Boron Concentration in the React or Coolant".

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IV.

NEVIEW GUIDELINES The purpose of this evaluation.is to identify inadvertent con-k trol rod withdrawals and malpositioning of control rods which may" occur.as a result of single failure,'in the control rod' drive system for the Haddam. Neck Nuclear Power Plant.

V.

E V.A L U AT 7 0N Information was provided in Connecticut Yankee Atomic Power Cc pany' Letter dated May 18, 19 81 r describing single failures within the c on't r o l rod drive system which can.cause control rod withd'rawals und malpositioning of control rods at the l

Hoddam Neck' Nuclear Power Plant.

Also included,was a des-cription of design features which limit reactivity insertion P

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rates and rod malpositionings resulting from single failures.

Based upon an audit review of the information provided b'y the fotL wing may occur as a ' result U censee we conclude that the 9

of single failures:

1),Two banks of control rods may move simultan-eousty instead of one bank.

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Two s u b g'r o u p s of control rods could move simultaneously instead of o n.e subgroup.

3)

A clustere subag,oupe' or bank of shutdown rods may not o =

move when movement is commanded.

4)

A clusteri clusterse subgroups banks 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 rt ent ly.

7)

An individual shutdown rod or a clustere sybgroup, bank or banks of shutdown rods could fall into the core.

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8)

An individual control rod or clustere clusterse subgroupe f

bank or banks of control rods could fall into the core.

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This conclusion is based upon the design of the cont.rol rod drive system.

It should be noted that the licensees in his l,e t t e r s states that item 1 above c9uld 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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