ML20150B741

Forwards Requirements for Subj Facil Cold Shutdown.Req Comment Prior to Issuance of SER

ML20150B741
Person / Time
Site:	05000580, 05000581
Issue date:	10/27/1978
From:	Vassallo D Office of Nuclear Reactor Regulation
To:	Mcwhorter F OHIO EDISON CO.
References
NUDOCS 7811080241
Download: ML20150B741 (5)

Text

,

n .1 . . . ..-- -

, _; ._ 2 ; .

i -

.. A  ;

f #% unn to n 4Tes .

g% 'g NUCLEAR REGULAT ORY COMMISslON WASHINGTON, 0, C. 205SS i

.j

{ ..

%, [ OCT :: 7 nya .

=....

Docket Nos. STN 50-580 and STN 50-581 l

Mr.. Robert J. McWhorter Vice President l Ohio Edison Company 76 South Main Street Akron, Ohio 44308

Dear Mr. McWhorter:

4

SUBJECT:

REQUIREMENTS FOR COLD SHUTDOWN ON THE ERIE NUCLEAR PLANT 1 In our letter to you dated March 31, 1978, we indicated our requirement for additional information and specifically stated our position (Item 211.77) regarding design requirements for the Erie Nuclear Plant to provide a means of achieving a cold shutdown condition using only safety-grade equipment. This design requirement was also-included in our Preliminary Design Approval No.12 issued for the Babcock & Wilcox StandardSafetyAnalysisReport(BSAR-205)whichisreferencedinthe Erie Nuclear Plant application.

We have subsequently had extensive discussions with Babcock & Wilcox regarding this matter with the view of providing additional guidance.

We have documented this guidance in the Enclosure.

Although several of the design requirements for cold shutdown apply solely to systems;in the BSAR-205 scope of design, we require that the epplication for the Erie Nuclear Plant reflect a specific commitment to comply with our reouirements as indicated in'the Enclosure for the totG Erie Nuclear Plant design. We require your commitment on this matter prior to the issuance of the Supplement to the Safety Evaluation Report.

Please contact us if you have any questions regarding this matter.

~

Sincerely, L

D. B. Vassallo, Assistant Director for Light Water Reactors

~

Division of Project Management o

Enclosure:

As Stated

ces w/ enclosure: .

7 8110 8 0 A ([/

See~page 2:

l _ . . _ ._ . _ .

r ,

L ,

l: .

• Mr. R.. J. McWhorter l Vice President i Ohio Edison Company 1 76 South Main Street Akron, Ohio 44308 cc: Mr. B. M. Miller Ohio Edison Company 76 South Main Street Akron, Ohio 44308 Mr. William Kessler Commonwealth Associ,ates, Inc.

209 East Washington Jackson., Mi,chigan 49201

' Gerald Charnoff, Esquire -

Shaw, Pittman, Potts & Trowbridge 1800 M Street, N. W.

Washington, D. C. 20036 Thomas A. Kayuha. Esquire Ohio Edison Company 76 South Main Street Akron, Ohio 44308 Mr. A. H. Lazar Babcock and Wilcox Power Generation Group P. C. Box 1260 Lynchburg, Virginia 24505 Mr. Robert W. Tufts 352 West College Street Oberlin, Ohio 44074 Ms.' Evelyn Stebbins 705 Elmwood Road Rocky River, Ohio 44116 Mr. Richard E. Webb 2858 One Hundred Eleventh Street Toledo, Ohio 43611 i.

[ ,

b'

a . .

- ~

== := . =. =.=.m = :.= mo a . ..~

t l: s ....  ;

~~

ENCLOSURE <

l I

COLD SHUTDOWN REOUIREMENTS FOR

^

dUE UNIT $~l T 2 l

i 1

For each part of our cold shutdown position, clarification, if necessary,  !

is provided as follows:

Provide safety-grade steam generator dump valves, operators, air  :

and power supplies uhich meet the cingle failure criterion. l The staff position is that,-for applications not yet docketed, local manual operation of the MADV's will. not be acceptable, except to mitigate the consequences of a single active failure. Operation from the control room, for.the time. necessary to cool the plant to initiation of the decay heat removal system, will be required. Local manual operation, if secessary, would be approved for dump valves in plants now under construction and for active applications for which an SER has been written. Justification for the acceptability of local operation must' include actual local test.

operation of the MADV's, showing that the plant can be cooled in a controlled manner and that the MADV's can be operated safely and effectively. It is I assumed that the valve body, etc., is designed to seismic Category I i requirements and that manual operation could be achieved following a safe shutdown earthquake.

Provide the capability to coot doun to cold shutdoun in tess than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, assuming- the most timiting single failure and uith only offsite or onsite power available, or shou that manual actions inside

' or outside containment or return to hot standby until the manual actions or maintenance can be perfomed to correct the failure provides an acceptable atternative.

,The staff now requii'es that assuming the most limiting single failure, with .

'only offsite or onsite power available and a safe shutdown earthquake, capability must exist to cocf down.to the decay heat removal system cut-in lcondi.tions (rather.than cold shutdown) in approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

~~-

~ ~

.. - .=-.._:=. .. .- . ... = _ .-- . -

a 2

The staff position is that the current heat removal capacity is inadequate if this criterion can not be met. B&W's calculations for Erie indicate that if one of the two available MAD valves is mechanically stuck closed, the plant cooldown time would be extended to at least several days. The staff considers this time excessive. Accordingly, we require that additional cooldown capability be provided. The addition of two MADV's (one per steam generator) with the same capacity as the original valves would be an acceptable approach.

Provide the capability to depressurize the reactor coolant system with only safety-grade systems assuming a single failure and with only offsite or onsite power available or shou that manual actions inside or outside containment or remaining at hot standby until manual actions or repairs are complete provides an acceptable alternative.

Provide the capability for coration with only safety-grade systems assuming a single failure and with only offsite or onsite pouer available, or shou that manual actions inside or outside containment or remaining at hot standby until manual action or repairs are completed provides an acceptable alternative.

The staff considers it acceptable to stay at hot shutdown for the time necessary to correct single failures, provided the overall cooldown time to reach DHR cut-in conditions is approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. In providing the capability to depressurize and borate the reactor coolant system, assuming a single failure and loss of offsite power, local operator action will be permitted to correct failures, if shown to be acceptable (including consideration of accessibility of required equipment). Availability of nonseismic Category I equipment may not be assumed.

The staff requires that the highest worth contfoi r6d is assumed at the fully withdrawn position when considering boration requirements.

a

.. -- =.- -- . . - =

o

.3- l OCT e ; 373 j

-conduct or reference approved prototype qualification tests to study i the mixing of the added borated ucter and the cooldoun under natural circulation conditions with a worst-case single failure (i.e., a single failurc of a steam generatcr atmospheric dump valve). These tests and analyses vill be used to obtain infomation on cocidoun times and the corresponding auxiliary feeduater requirements.

l

- A single prototype qualification test on the lead plant of a given design is acceptable. However, other tests might be required due to differences in system or component arrangement, procedural differences, new questions concerning accessibility or safety for manual actions, or other concerns not addressed by the initial prototype test.

Provide specific procedures, at the operating license revico stage, for cooling doun using natural circulation, and submit a sumary.

outline of these procedures during the construction permit revicu.

Provide or require a seismic Category I au.-iliary feedvater supply for at least four hours at hot shutdoun plus cooldoun to the decay heat removal systen cut-in based on the longest time (for only onsite or offsite power and assuming the vorst single failure),

or shou 'that an adequate alternate seismic Category I source vill be available.

Meetings with Babcock and Wilcox did not indicate that clarification of i

these parts of our position was necessary.

/

i

(

1 .

La%'

. .n

OV

[ T4 UNIT ED ET ATES NUCLEAR REGULATORY COMMisslON

[

f .7 W ASHINGTON, D. C. 20555

1. OCT 2 7 rqa

....+

Docket Nos. STN 50-580 and STN 50-581 Mr. Robert J. McWhorter Vice President Ohio Edison Company 76 South Main Street Akron, Ohio 44308

SUBJECT:

REQUIREMENTS FOR COLD SHUTDOWN ON THE ERIE NUCLEAR PLANT In our letter to you dated March 31, 1978, we indicated our requirement for additional information and specifically stated our position (Item 211.77) regarding design requirements for the Erie Nuclear Plant to provide a means of achieving a cold shutdown condition using only safety-grade equipment. This design requirement was also included in our Preliminary Design Approval No.12 issued for the Babcock & Wilcox Standard Safety Analysis Report (BSAR-205) which is referenced in the Erie Nuclear Plant application.

We have subsequently had extensive discussions with Babcock & Wilcox regarding this matter with the view of providing additional guidance.

We have documented this guidance in the Enclosure.

Although several of the design requirements for cold shutdown apply solely to systems in the BSAR-205 scope of design, we require that the application for the Erie Nuclear Plant reflect a specific commitment to comply with our requirements as indicated in the Enclosure for the total Erie Nuclear Plant design. Wa require your commitment on this matter prior to the issuance of the Supplement to the Safety Evaluation Report.

Please contact us if you have any questions regarding this matter.

Sincerely, t

D. B. Vassallo, Assistant Director for Light Water Reactors Division of Project Management

Enclosure:

As Stated ces w/ enclosure:

'. See page 2 - - - _ _ _ _ _ _ _ - _ _ _ - _ _ _ _

.. - . _ . _ _ - _ . - - . - ~

.o Mr. R. J. McWhorter Vice President Ohio Edison Company 76 South Main Street Akron, Ohio 44308 cc: Mr. B. M. Miller Ohio Edison Company 76 South Main Street Akron, Ohio 44308 Mr. William Kessler Commonwealth Associ.ates, Inc.

209 East Washington Jackson., Mi,chigan 49201 Gerald Charnoff, Esquire Shaw, Pittman, Potts & Trowbridge 1800 M Street, N. W.

Washington, D. C. 20036 Thomas A. Kayuha, Esquire Ohio Edison Company 76 South Main Street Akron, Ohio 44308 Mr. A. H. Lazar Babcock and Wilcox Power Generation Group P. O. Box 1260 Lynchburg, Virginia 24505 Mr. Robert W. Tufts 352 West College Street Oberlin, Ohio 44074 Ms. Evelyn Stebbins 705 Elmwood Road Rocky River, Ohio 44116 Mr. Richard E. Web _b 2858 One Hundred Eleventh Street Toledo, Ohio 43611

+

~, ....

~

ENCLOSURE _

COLD SHUTDOWN RE0UIREMENTS FOR

_ ERIE UNITS 1 & 2 For each part of our cold shutdown position, clarification, if necessary,

~

is provided as follows:

Provide safety-grade steam generator du.p valves, operators, air and power supplias which meet the singic failure criterion.

The staff position is that, for applications not yet docketed, local manual operation of the MADV's will not be acceptable, except to mitigate the consequences of a single active failure. Operation from the control room, for the time necessary to cool the plant to initiation of the decay heat removal system, will be required. Local manual operation, if necessary, would be approved for dump valves in plants now under construction and for active applications for which an SER has been written. Justification for the acceptability of local operation must include actual local test operation of the MADV's, showing that the plant can be cooled in a controlled manner and that the MADV's can be operated safely and effectively. It is assumed that the valve body, etc., is designed to seismic Category I requirements and that manual operation could be achieved following a safe shutdown earthquake.

Provide the capability to cool acun to cold shutdoun in less than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, assuming the most limicing single failure and uith only offsite or onsite power availabis, or shou that manual actions inside or outside contaim:ent or return to hot standby until the manual actions or maintenance can be per'ormed to correct the failure provides an acceptable alternative.

,The staff now requilFes that assuming the most limiting single failure, with

'only offsite or onsite power available and a safe shutdown earthquake, capability must exist to cool down to the decay heat removal system cut-in conditions (rather than cold shutdown) fn approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. _

4 The staff position is that the current heat removal capacity is inadequate if this criterion can not be met. B&W's calculations for Erie indicate that if one of the two available MAD valves is mechanically stuck closed, the plant cooldown time would be extended to at least several days. The staff considers this time excessive. Accordingly, we require that

< additional cooldown capability be provided. The addition of two MADV's (one per steam generator) with the same capacity as the original valves would be an acceptable approach.

Provide the capability to depressurize the reactor coolant system uith only safety-grade systems assuming a single failure and uith only offsite or onsite power available or show that manual actions inside or outside containment or remaining at hot standby until manual e-tions or repairs are complete provides an acceptable alternative.

Provide the capability for boration with only safety-grade systems assuming a single failure and with only offsite or onsite cover available, or shou that manual actions inside or outside containment or remaining at hot standby until manual action or repairs are completed provides an acceptable alternative.

The staff considers it acceptable to stay at hot shutdown for the time necessary to correct single failures, provided the overall cooldown time to reach DHR cut-in conditions is approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. In providing the capability to depressurize and borate the reactor coolant system, assuming a single failure and loss of offsite power, local operator action will be permitted to correct failures, if shown to be acceptable (including consideration of accessibility of required equipment). Availability of nonseismic Category I equipment may not be assumed.

A The staff requires that the highest worth control rod is assumed at the fully withdrawn position when considering boration requirements.

+

. ~3 OCT q ; g g

. -Conduct or reference approved prototype qualification tests to study the mixing of the added borated water and the c:oldoun under natural circulation conditions with a ucrat-case single failure (i.e., a single failure of a steam generatcr atmospheric c:cp valve). These testo and analyses vill be used to obtain infomation on cocidoun times and the corresponding auritiary feedvater requirements.

A single prototype qualification test on the lead plant of a given design is acceptable. However, other tests might be required due to differences in system or component arrangement, procedural differences, new questions concerning accessibility or safety for manual actions, or other concerns not addressed by the initial prototype test.

Provide specific procedures, at the operating license revicu stage.,

for coolirag dotm using natural circulation, and submit a su, mary.

outline of these procedures during the construction permit revieu.

Provide or require a seismic Category I au:iliary feeduater supply for at least four hours at hot shutdoun plus cooldoun to the decay heat removal system cut-in based on the longest time (for only onsite or offsite pouer and assuming the worst single failure),

or shou ~that an adequate alternate seismic Category I source vill be available.

Meetings with Babcock and Wilcox did not indicate that clarification of these parts of our position was necessary.

/

4%

8b

g. =

l [ ' '

_ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _