3F1285-12, Confirms 850125 Notification to Adopt Gpu Approach to Analyzing Natural Circulation Cooldown (Generic Ltr 81-21).TMI Topical Rept on Subj Encl

Confirms 850125 Notification to Adopt Gpu Approach to Analyzing Natural Circulation Cooldown (Generic Ltr 81-21).TMI Topical Rept on Subj Encl

ML20138P137
Person / Time
Site:	Three Mile Island, Crystal River, 05000000
Issue date:	12/20/1985
From:	Eric Simpson FLORIDA POWER CORP.
To:	Stolz J Office of Nuclear Reactor Regulation
Shared Package
ML20138P139	List: 3F1285-12, Confirms 850125 Notification to Adopt Gpu Approach to Analyzing Natural Circulation Cooldown (Generic Ltr 81-21).TMI Topical Rept on Subj Encl ML20138P154
References
3F1285-12, GL-81-21, GL-81-212, NUDOCS 8512240320
Download: ML20138P137 (3)

Text

,

.4 ,#'

, y ese e .

je se*e

?

ese

. Power C@RPO R AT ION '-

December 20,1985

- 3F1285-12 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch #4 Division of. Licensing U.S. Nuclear Regulatory Commission -

- Washington, DC 20535

Subject:

Crystal River Unit 3

' Docket No. 50-302 '

Operating License No. DPR-72 RESPONSE TO NRC GENERIC LETTER 81-21 NATURAL CIRCULATION COOLDOWN

Reference:

1) FPC letter to NRC, Westafer to Stolz, dated January 25,1985

2) aMUD letter to NRC, Rodriguez to Director, NRR, dated September 19,1985

Dear Sir:

The reference 1) letter indicated that, based on our initial review, the current plan by Florida Power Corporation (FPC) was to. adopt the General Public Utilities Nuclear'(GPUN) approach for analyzing natural circulation cooldown in the Crystal River 3 (CR-3) generating station.

Review of the Sacramento Municipal Utilities District (SMUD) submittal, reference 2, and its attachments has confirmed FPC's belief that the analytical assumptions used by GPUN are reasonable for the application to TMI-l and, because of the geometrical similarity, are also applicable to CR-3.

The attachments to this letter include the GPUN analysis (Topical Report 017, Rev.

-1) and notes, by section, on' application of the analysis to CR-3. -

hO bg Sincerely, ,

rs j x E. C. Simpson

. Director, Nuclear Operations ao - n. ceurcur m a a tt aa m Engineering and Licensing L%/Z*"'

Attachments EHD/feb 8512240320 DR 851220 7 ADOCK 05000302 PDR G EN ERAL OFFICE 3201 Thirty-founn Street South e P.O. Box 14042, St. Petersburg, Florida 33733 e 813-866 5151

- ~

g

,.w , . 7 JK m ,

~

) '

x

..o ,~

1 Attachment to PPC Letter 3F1285-12.

~

-+  ; NOTES ON SECTIONS OF TOPICAL REPORT 017 REVISION 1

- WHICH ARE-APPLICABLE TO CRYSTAL RIVER 3 (CR-3)

- f

SUMMARY

? Thel analysis ~. methods Tused i and the' results' contained in . Topical ~ Report 017,-

7 Revision' 1,i"TMI-15 Nuclear Generating Station : Natural . Circulation : Cooldown

. 5 Analysis Without: Reactor! Vessel' Upper; Head Vold Formation", are appropriate lfor x -

. the :CR-3 Nuclear Generating l Station. The TMI-1 and ~CR-3 reactor vessels are-Evirtually; Identical.? The analyses contained in Topical Report 017, Revision' 1, were

? run to reactor coolant system (RCS) conditions of 204 F to envelop differences in

. decay heat removal (DHR) system cut-in' temperatures and pressures. - .

The Ti$41-1 cooldown times are based on _(DHR) system. cut-in at' 325 psig.with a:

j icorresponding RCS saturation: temperature in the; reactor vessel head of'429 F.'

. The CR-3' DHR cut-In: occurs at'284. psig with a corresponding RCS saturation

@+ ' temperature in the reactor vessel head of 417 F. : The results indicate.that for an JRCS cooldown rate of 50 F/hr tof 280 F, the time required to cool the reactor

~

~

$ ] vessel head to 417 F is'on the order of 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />.

l.0 ; INTRODUCTION' ,

s ~-

i" :1.11 Backdroundi m

{

- ~% , JThis section is valid for.CP,-3.

. 3

,y k ^;

Lt.2I'NRC Concerns and Requirements'

This section is valid for CR-3. - '

R ,

1.3 : CR-3 RCS' Natural Circulation Cooling Procedure g  ; Assuming' that - the amount L of capacity' listed in the - Technical

~

4  ; Specifications (130,000 gallons of which 139,000 gallons is usable) is the' l Lonly emergency feedwater (EFW) source, cooldown of. the RCS'would 4 >,

"need to be completed in about 15 hrs. to ' avoid depletion of the capacity prior.to' reaching the: decay, heat removal conditions of 280 F and 284 -

~

f- - iPsig.- ,

iThere:Isla statement in the : Technical Specifications bases for CR-3 which Indicates that'the reactor decay heat may be removed by the

,,.ep i ' condensate storage tank-supply' of water for a period of more than 24.

- ,- ' hours. Wel believeL:that this statement. was the result , of multiple

( w ichangesi tof the ! pre-license Technical ~ Specifications that at first fincluded the condenser hotwell'In the Limiting Condition for Operation

< and was later deleted. -

. If an eatended loss of offsite power is assumed, emergency feedwater is W available?from ithe ? CR-3-; condensate storage tank and condenser hotwells. The total EFW availability is about 300,000 gallons, which would support an average cooldown rate as low as approximately 9 F/hr.

qMuwa - uw &

4 - . - _ __ . ~ . _ . . . . _ _ . _ ._ _ _ . . . . _ . . ~ . . . . . . - .. .

. - - . . . - - - .~ ~ .. - - . - - - -

_ A -

/ -

-' msg g -

'(s, - '

1 ve' '

h '

Onder assumptions whichLinclude availability of EFW from-the pr wary -

source'(condensate storage tank) plus other CR-3. site and nearb) fossil-w"

electric lgeneratingjplant sources, the supply of EFW'Is adequate to

~ ;

assure : natural 4 circulationi cooldown a to -- DHR conditions at - small -

cooldown rates.1 1' L FPC,'therefore, commits to: -

~-

7s F;' - m ~L", _

7a):: sprovide h operator 1 training b to 7 assure : understanding of. the' fdifference between :likely.. sources =of-. water and ~the technical : .

e - ,

,- 3pecification limitations.' '

sb)L:. TreviseJthe erdergencyLoperating procedures to; assure cooldown -

_ rates which lie within the ranges _ specified in the GPUN a'ralysis - ,

i; . (modifiedito JCR-3 f conditionsDto avoid formation . of a' steam bubble in the reactor vessel head.1

. m j;m ?c) ~reviseJ thef emergency 'and' operating procedures to assure RCS :

, cooldown rates .which preclude depletion of available: emergency

-a 1 , y ffeedwater sources. prior;to ; reaching _ RCS conditions 'of 284 psig and 280 F.'

l -- -

JupciateithkTEchNicallSpecifications. and the FSAR to provide Ed)

, , ~ . consistency for natural circulation cooldown.

a; . l

~

. 1.4j iTMI-.12 Natural' Circulation Cooldown Analysis- Without-Reactor Vessel 7 -

. Upper Head Void Formation-sThissection is valid for CR-3 with the exception that the DHR system p'"- =

cut-in conditions at.CR-3 are 284 psig and RCS temperature of L280 F.

iTo cut-in:the DHR system, the' temperature of the fluid in the upper vessel head must be less than the satu.ation. temperature (417 F) which icorresponds to 284'psig.

[^

s

, ,2.0' LRE CTOR VESSEL OPPER HEAD COOLDOWN PROCESSES

.  : This section is valid for CR 3. -

M3.0 J : HEATING 6 MODEL OF TMI-l UPPER HEAD 1

Ms $1on is valid for CR'-3 (including Sections 3.1 through 3.6).

T4.d j 7ANALYSIS RESULTS : ,

a; .,

c

• (This section is valid for CR-3.

3.0 i ; OPER ATIONAL GUIDELINES ,

, n .

5This section is applicable to CRl3. .  !

" - 6.0 - ? CONCLUSIONS .

m s.

- [This section is' ~ applicable 'to CR-3, except for the CR-3 DHR initiation >

condition below 284 psig and 280 F.

' ;n

LlN & - -

'-