ML20005A061

Forwards NRC Resolution of Util Comments Re SEP Topic VI-10.B & Final Safety Evaluation.Assessment May Be Revised in Future If Facility Design Is Changed

ML20005A061
Person / Time
Site:	Millstone
Issue date:	06/23/1981
From:	Crutchfield D Office of Nuclear Reactor Regulation
To:	Counsil W NORTHEAST NUCLEAR ENERGY CO.
References
TASK-06-10.B, TASK-6-10.B, TASK-RR LSO5-81-06-095, LSO5-81-6-95, NUDOCS 8106290312
Download: ML20005A061 (7)

Text

%

Y W

W s

n June 23, 1981

-/

Docket No. 50-245 n a jU LS05-81-06-095 s

/,

4 JUti 2 61981

• D i Mr. W. G. Couns11, Vice President

{

,,5 -

m f)/

Nuclear Engineering a:ed Operatiores an===

Northeast Nuclear Energy Company Pust Office Box 270 Ms '

\\

Hartford, Connect.kut 06101 on.

SUBJECT:

COMPLETION OF SEP TOPIC VI-10.B. " SHARED SYSTEMS FOR MULTI-UNIT STATIONS"

References:

(1) Letter Zi m nn to Counsil, March 19, 1979 (2) Letter, Cou.isil to Ziemann, April 27, 1979 In Refereace (1), the NRC staff transmitted tc Northeast Nuclear Energy Company (flNEco) the draft evaluation of the above subject SEP topic and requested that NNECo review its factual correctness as it pertained to the Millstone Nuclear Power Station, Unit No.1.

In response, Reference (2), NNEco 1ndicated that the fire protection water system and the 357 foot stack warranted additional consideration by the NRC staff. Also, NNECo did not receive the bottom part of our report.

We have re-examined these systems in light of NNECo coments and determined (see Enclosure 1) that the original assessment is still val.d. As a result, we now consider the previous draft evaluation final and have re-issued it as.

This assessment may be revised in the future if your facility design is changed or the NRC criteria relating to this topic are modified be-fore the integrated assessment is completed.

Sincerely, Dennis M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensi~J

Enclosure:

i8106290 b

l cc w/ enclosure: f See next page 7

g,,l,,SEPg'ssell "cO!.SjPB

,,l,SEPB b/

p 0

,l,A Sp:DL lWRu

,~oi SBrowrr:51 !RHermann JSlieu D

eld G fnas 6/(/81 6//c/81 6/g/81

, 6/$1/81 l

6/MN1

6/[/81 i

.ii

. 7 7.; u. R.{ C O.: ; ;;

S'*

u-x

[p* **:gjo,,.

UNITED STATES NUCLEAR REGULATORY COMMISSION e

o nE WASWNGTON, D. C. 20555

'f g ' y f gJ June 23, 1981

+....

Docket flo. 50-245 LS05-81-06-095 Mr. W. G. Counsil Vice Presitant Nuclear Engineering and Operations Northeast Nuclear Energy Company Post Office Box 270 Hartford, Connecticut 06101

SUBJECT:

COMPLETION OF SEP TOPIC VI-10.B. " SHARED SYSTEMS FOR MULTI-UNIT STATIONS"

References:

(1) Letter, Ziemann to Counsil, March 19, 1979 (2) Letter, Counsil to Ziemann, Ap'ril 27, 1979 In Reference (1), the NRC staff transmitted to Northeast Nuclear Energy Company (NNEco) the draft evaluation of the above subject SEP topic and requested that NNECo review its factual correctness as it pertained to the Millstone Nuclear Power Statica, Unit No.1.

In response, Reference (2), hNEco indicated that the fire protection water system and the 357 foot stack warranted additional consideration by the NRC staff. Also, NNECo did not receive the bottom part of our report.

We have re-examined these systems in light of NNECo coments and determined (see Enclosure 1) that the original assessment is still valid. As a result, we now consider the previous draft evaluation final and have re-issued it as.

This assessment may be revised in the future if your facility design is changed or the NRC criteria relating to this topic a'e modified be-fore the integrated assessment is completed.

Sinceraly, j/

p.

dennis M. Crutch ie d, C ef Operating Reactors Branc No. 5 Division of Li~ nsing

Enclosure:

As stated cc w/eirciosure:

See next oage

unuuwsonu.

RESOLUTION OF HNEco'S COMMENTS

• 1.

UNECo - The 357 foot stack is shared and is considered to be important to safety.

NRC - Based on the information'provided in the Millstone Unit 2 FSAR, we have concluded that the filtration systems, which disperse ef-fluent via the stack for Units 1 & 2 are both independent and void of possible system interactions. The design adequacy of the stack, which appears to be the common feature of the filtration systems, is being evaluated under SEP Topic III-6, Seismic Design Consider-ations".

2.

NNECo - The draft evaluation requires further elaboration with respect to the fire protection system as a water source (for systems such as the isolation condenser) and the shared portions of that system.

NRC - The fire protection system as a water source was purposely not ad-dressed in this evaluation. Our rat.icnale for this action was based on our understanding of the lystem.

It'is our understanding that the isolation condenser contains enough water for 30 minutes of operation and can utilize either the condensate storage system or the fire protection system as secondary water sources. As dis-cussed in the safe shutdown review, the isolation condenser is not included on the minimum list of systems required for safe shutdown.

For small break mitigation, less than 10 minutes of operation is required so nu makeup is needed for the isolation condenser to fulfill its function.

Therefore, the ' fire protection system was not included in this evaluation. The remaining portion of the fire protection system is being evaluated under SEP Topic IX-6.

N

• See Letter, Counsil to Ziemann, April 27, 1979 P00RBRGIRL 1

EtiCLOSURE 2 e

SEP REVIEW OF SHARED ENGINEERED SAFETY FEATURES, ONSITE EMERGENCY POWER, AND SERVICE SYSTEMS FOR hoLTIPLE U!!IT STATIONE" TOPIC VI-10.B 4

(

"This evaluation deals only with non-EI&C equi;: ment r.nd structures and should be combined with the EI&C review of this topic when it is completed.

~~

l

• .e

?00R ORGIML

~

,,e..

=k

.n c.

t 1

l INTRODUCTION The safety objective of Topic VI-10.B is to assure that:

(1) the interconnection of ESF, on-site emergency power, and servica systems

'between different units are not such that a failure, maintenance or testing operation in one unit will affect the accomplishment of the protection function of the system (s) in other units, (2) the required coordination be. ween unit operators can cope with an incident in one unit and safe shutdown of the remainir:g unit (r,), and (3) system overload conditir as will not arise'as a c,onsequence of an accident in one unit coincident with a spurious accident signal or any other single failure C

in another unit. This objective applies only to Safety related equipment and structuris.

The sharing of structures, systems and components important to safety for a multiple unit facility can result in a reduction of the numbe and of the capacity of on-site systems to below that which normally is provided for the same number of units located at separate sites. NRC General Design Criterion 5, " Sharing of 5tructures, systems and components," was developed to ensure that sharing of structures, systems, and c:c.gonants important te safety amor.g nuclear pc.:sr units will not significantly impair thair stility to perforn tr.Eir sefaty functions, including,,in the event of an accident in one unit, orderly shutdown and cooldown of the remaining units.

• O

• O

. ~.C:.

s,

t.

This evaluation addresses only the non-Ele'ctrical, Instrumentation, and Control (EI&C) portions of this topic 1.e fluid systems and components and structures. The EI&C portions'will be evaluated later in the SEP.

In the course of this evaluation, we determined that the review of shared structures and equipment at the Dresden Unit Nos.1 and 2

~

facilities could not be completed prior to the cc:pletion of other related SEP topic reviews. These related topics are identified in the evaluation; and, upon completion of these topics, this evaluation will be updated. Topic VI-10.B is applicable to the following SEP plants which are located at muTtiple unit sites:

San Onofre 1 Millstone 1 f

Dresden 1 and 2 Evaluation and Conclusion San Onofre 1 San Onofre Unit 1 is an operating plant which utilizes a Wastinghouse pressurized water reactor for its nuclear steam supply system while

. Units 2 & 3, which utilize Comb.ution Engineering pressurized water reactors for their nuclear r, team supply systems, are under review for

~"the issuance of operating licenses..

Shared systems is a revir.; cer.:ern d.':h is nor.al'y addressed in tr$

course of a.. 0;srating License ' eviE.e.

The.:f r.a1 Itfe:y Ar.slytis F.s;:rt for San Onofre Units.2 and 3 discusses shared structurss, systems and s

~

P00ffDRGul

~

~

=.;;;

y c

\\

.g.

.. -S ccmponents for Units 2 and 3.only and does not identify any interfaces betweeni.heseunitsandUnit1. Therefore, the staff conducted a review to identify and evaluai.e the structures and equipment shtred between Unit 1 and Units 2 and 3.

Based on this review, we identified the Service Water Reservoir (SVR) as the only shared component which could affect the safe shutdown capability of Uait 1*.

This is because the SWR provides water to both the Unit 1 fire protection water system, which can be used to supply water to the other units, and to the Unit I safe shutdown systems (Auxiliary Feed System). How:ver the Unit 1 Technical Specifications (Section 3.4 and 3.14) acceptably account for this sharing of the SWR by requiring.the licensee to maintain adequate SVR

,(-

water inventory for both safe shutdown and fire fighting purposes.

Based on the results of our review as summarized above, we conclude that

1) the safety objective of Topic VI-10.B is met for San Onofre 1, and 2) the sharing of the SWR is in conformance with GDC 5.

Millstone 1 Millstone Unit ? utilizes a pressurized water reactor for its nuclear steam supply system (NSSS), while Unit I utilizes a boiling water reactor for its NSSS.

The Unit 2 Final Safety Analysis Report (Amendment 39, 3

page 1.2-17) identifies facilities and systams which are shared between the units.

Based en our review of these facilities an: systcms we c nch:ds that

" Refer to tne SEP Review of Safe Shutcown Syste=s for San Onofre 1.

(

100R BR E R e n aeae mW e9 m

-_y

..a 5-

[

1) the only shared system impi rtant to safety is the fire protection water system, which has been previously evaluated as a shared system in Millstone 1 License Amendment No. 53, dated September 26, 1978, and

2) the fire protection system is not needed for the safe shutdown

,of Unit l'. Therefore, the safety objective of Topic VI-10.3 is met for Millstone 1, and the fire protection water system is in conformance with GDC 5.

o i

~

s.'

" Refer to the SEP Reviea of Safe' Shutdown Systems for Millstone 1.

• e

^

hfk

.