ML20133K540

Requests Info to Clarify Role of Feed & Bleed Core Cooling Method in Primary Design Basis,Including Analysis of Primary Sys Response for Transients & Accidents Relying on Feed & Bleed as Principal Means of DHR

ML20133K540
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	10/17/1985
From:	Thompson H Office of Nuclear Reactor Regulation
To:	Opeka J CONNECTICUT YANKEE ATOMIC POWER CO., NORTHEAST NUCLEAR ENERGY CO.
References
LSO5-85-10-025, LSO5-85-10-25, NUDOCS 8510220138
Download: ML20133K540 (4)

Text

.

6,, UNITED STATES

['3 g NUCLEAR REGULATORY COMMISSION

E WASHINGTON. D. C. 20555 October 17, 1985 k * *... o

~

Docket No.: 50-213 -

LS05-85-10-025 Mr. Jchn F. Opeka, Senior Vice President Nuclear Engineering and Operations

-Connecticut Yankee Atomic Power Company Northeast Nuclear Energy Company Post Office Box 270 Hartford, Connecticut 06141

SUBJECT:

ENVIRONMENTAL QUALIFICATION OF EQUIPMENT OUTSIDE CONTAI?: MENT Re: Haddam Neck Plant In a meeting on October 2,1985, you referenced several previous staff evaluations concerning the use of " feed and bleed" as an alternative core cooling method for high energy line breaks outside containment. Relative to our letter dated Septembe" 30, 1085, on the same subject, we acknowledge that the Connecticut Yankee Atomic Power Company (CYAPCo) has referred to

. " feed and bleed" methods of core cooling in various licensing submittals on plant design issues, including conformance with 10 CFP, 50.49 for equipment located outside containment. However, the extent to which " feed and bleed" constitutes the primary design basis, as opposed to a supporting heat removal method, and the extent to which the staff has reviewed it in that context has not been clearly established. Therefore, the staff is currently reviewing the licensing records and related design information related to the Haddam Neck " feed and bleed" capability in order to resolve this matter.

As described in our letter of September 30, 1985, and discussed on October 2, 1985, the staff does not believe that " feed and bleed" methods should constitute the primary means to mitigate design-basis accidents. These methods have inherent uncertainties associated with (1) the ability to control a primary system loss of coolant; (2) the operability of power-operated relief valves, under accident conditions, for extended periods of time; and (3) the core thermal-hydraulic response. However, the staff does believe that such methods can be relied on for some interim period until reliable, primary .

heet removal methods can be' established, l 1

8510220138 DR 851017 ( '

p ADOCK 05000213 .- \..

PDR ~

L

Pr. John F. Opeka October 17, 1985 In order to complete this evaluation, we require the following information, formally submitted with appropriate references to previous submittals, to clarify the role of " feed ard bleed" in the Ha'ddam Neck design basis:

1. Provide the results of the analysis of the primary system response for those transients and accidents that rely on " feed and bleed" as the prir.cipal means of decay heat removal. Include a description of the analytical assumptions.

2. Surrarize' the emergency operating procedures for " feed and bleed", and describe the circumstances under which alternative equipment wculd be used (e.g., letdown and charging).

3. Identify the heat removal systers and components outside containment and the specific high energy lines whose rupture would expose then to a harsh envirorcent.

In addition, you shculd submit any other infomation which you feel is relevant to this evaluation. We request that the inforr:ation described above be submitted as senn as practical, but not later than 45 days followino ycur receipt of this letter.

This request affects fewer than ten respondents and, +herefore, an OPB clearance is net required in accordance with P.L.96-511. Should you have any questions concerning this matter, please contact the NPC Project Manager, F. Akstulcwicz.

't

) / Hugh L. Thompson, Jr., Director

/ Division of Licensing

• SEE PREVIOUS PAGE FOR CONCURRENCE

-V \ O 9

SEPB:DL N OFPff:PL SEPB:DL* A  :

FAkstulew!c$ JZwolinski CGrimes D field 10/n /85 10/o/85 10/11/85 10/g\/85

(#

D:DSI RBern ro h .

HT omp [

DISTRIBUTION Docket 0 ELD CJamerson 10/;(/85 10//gC5 NRC PDR EJordan JZwolinski Local PUR BGrimes ACRS (10)

ORB h RDG JPartlow LGrimes HThompson FAkstulewicz SEPB RDG RBernero

1 1 Mr. John F. Opeka i i thermal-hydraulic response. However, the staff does believe that such j methods can be relied on for some interim period until reliable, primary ~

l heat removal methods can be established.

! In order to complete this evaluation, we require the following information, 4 formally submitted with appropriate references to previous submittals, to j clarify the role of feed and bleed in the Haddam Neck design basis:

I

! 1. Provide the results of the analysis of the primary system response for l those transients and accidents that rely on feed and bleed as principal means of decay heat removal. Include a description of the analytical

~

assumptions.

i l 2. Summarize the emergency operating procedures'for feed and bleed, and i describe the circumstances under which alternative equipment would be j used (e.g., letdown and charging). ,

3. Identify the heat removal systems and components outside containment i and the specific high energy lines who'es rupture would expose them to l a harsh environment. /

In addition, you should submit any other information which you feel is l relevant to this evaluation. We reque'st that the information described t above be submitted as soon as practical, but not later than 45 days i following your receipt of this lettfr.

This request affects fewer than t'nerespondents and, therefore, an OMB clearance is not required in accordance with P.L.96-511. Should you have any questions concerning this, matter, please contact the NRC Project Manager, i F. Akstulewicz. ,

! /

l l / Hugh L. Thompson, Jr. , Director

/ Division of Licensing l

l l l SEPB:DL ORB #5:DL SEPB:D h AD:SA:D:

1 FAkstulewicz JZsolinski CGrimes DCrutchfield 10/ /85 0/ /85 10/g/85 10/ /85 i

D:DSI D:DL RBernero HThompson

, 10/ /85 10/ /85 i

i  !

!._ i

Pr. John F. Opeka Connecticut Yankee Atomic Power Company Haddar Neck Plant CC: ,

Gerald Garfield, Esquire _

kevin McCarthy, Director Day, Berry & Howard Radiation Control Unit Counselors at Law Department of Environmental City Place Protection Hartford, Connecticut 06103-3409 State Office Building Hartford, Connecticut 06106 Superintendent Heddam Neck Plant

-RDF #1 Post Office Box 127E East Hampton, Connecticut 06424 Edward J. Mroczka r- . - Vice President, Nuclear Operations -

Northeast Utilities Service Cotpany ..

Post Office Box 270 Hartford, Ccnnecticut 06141-0270 [

Board of Selectmen Town Hall Haddam, Connecticut 06103

. State of Conrecticut i Office of Policy and Management ATTN: Under Secretary Energy Division 80 Washington Street Hartford, Connecticut 06106 i

Resident Inspector Haddan Neck Nuclear Power Station c/o U.S. NRC East Haddam Post Office East Haddam, Connecticut 06423 Regional Administrator, Pepion I U.S. Nuclear Regulatory Commission 631 Park Avenue V.ing of Prussia, Pennsylvania 19406 <

4 l

l i 5

---

m- --e -n -

v- ,

-e n ,- - , , - .

,,.--r , -- -- - --, ,--.--,n---,.