ML20072T976

Forwards Supplemental Info to 821216 Safe Shutdown Analysis Rept,Including Revised Table of Contents & Revised Section 1.6, High Pressure/Low Pressure Interface Valves

ML20072T976
Person / Time
Site:	Clinton
Issue date:	04/05/1983
From:	Wuller G ILLINOIS POWER CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
U-0630, U-630, NUDOCS 8304110090
Download: ML20072T976 (7)

Text

. .

T1Hnnis Power Company $$_6 8 (04-05)-L 500 SOUTH 27TH STREET. P. O. BOX 511, DECATUR. ILLINolS 62525-1805 Docket No. 50-461 April 5, 1983 Director of Nuclear Reactor Regulation Attention: Mr. A. Schwencer Chief Licensing Branch No. 1 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Schwencer:

Subj ect : Clinton Power Station Unit #1 Safe Shutdown Analysis

References:

1) Clinton Power Station Unit #1 meeting on site (7/13/82); participants: Mr. Nick Fioravante and Illinois Power representatives.

2) Clinton Power Station Unit #1 Safe Shutdown >'

Analysis Report; U-0586 12/16/82.

3) Joint telephone conversation among Mr. Nick Fioravante of NRC and Illinois Power representatives.

In accordance with conversations held with Mr. Nick Fioravante of NRC (references 1 and 3), Illinois Power is providing supplemental information to its Safe Shutdown Analysis Report, reference (2):

i Page 2: A revised Table of Contents including section 1.6, "High Pressure / Low Pressure Interface Valves,"

(HP/LP) is attached.

Pages 10 and 10a: The attached new section 1.6 describes the HP/LP interface valves of concern. The Clinton Plant's operation staff has agreed to develop procedures i in accommodating the section 1.6 actions.

1 8304110090 830405 PDR ADDCK 05000461 A PDR

U 0630

-L30-83(04-05)-L April 5, 1983

-Page 2 Page 13: 'A recent analysis was conducted to determine if the RCIC equipment in fire zone A.l.4 is qualified for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following a fire in zone A.l.1.. That.

analysis was confirming and is reflected in the revised page 13 (attached). ,

Page 47: A footnote was added to page 47 indicating that a dedicated spool of. control wire (about 1300' minimum) will be stored on site in a specific location strictly for the replacement of_ Division 11 control wiring in the event of a fire in zone A.4.6.

The Clinton plant's maintenance staff has agreed to this action _and to the development of its required procedures.

We trust that these latest revisions to.our Safe. Shutdown Analysis meet with NRC approval.

Sincerely, l

1 G. E.AN Wullb; V r

Supervisor - Licensing Nuclear Station Engineering RWW/lt ~

cc: Dr.11. Abelson, NRC Clinton Project Manager Mr. J. E. Stang, Jr., NRC CEB Mr. H.11. Livermore, NRC Resident Inspector Illinois Department of Nuclear Safety I

l u

TABLE OF CONTENTS

1. Introduction 1.1 Purpose 1.2 Analysis Criterion 1.3 Evaluation Method 1.4 Assumptions 1.5 Associated Circuits 1.6 High Pressure / Low Pressure Interface Valves

2. Fire Area / Zone Shutdown Analysis

3. Modifications LIST OF TABLES

1. Divisional Equipment or Cable Located in Each Fire Zone 1.1 Systems Necessary for Safe Shutdown l 1.2 - Method #1 Mechanical Equipment List i

1.3 Method #2 Mechanical Equipment List 1.4 Electrical Equipment List 1.5 Instrumentation List 1.6 Fire Areas / Zones not Containing Safe Shutdown Equipment or Cable

, 1.7 Fire Areas / Zones Containing only one Division of Safe l

Shutdown Equipment or Cable 1.8 Panel Locations. .

l 1

all cables are IEEE 383 rated cables and wil1 not

-allow significant propagation beyond the impingement of the flame source.

i 1.6 High Pressure / Low Pressure Interface Valves There are only 6 valves that could be opened by a hot short in the control circuits in the event of a fire. They are:

1E12-F008 1E12-F052A 1E12-F087A 1E12-F009 1E12-F052B 1E12-F087B s

1.6.1 Valves 1E12-F008 and 1E12-F009 are installed in series. In order to prevent the spurious operation of valve 1E12-F008 in the event

- of a short, the breaker to valve 1E12-F008 will be locked open.

1.6.2 To prevent a short from opening valves 1E12-F052A and B, the power to these control-circuits will be controlled by two switches (Division 1 & 2) in the main control room.

f; Each division switch will be in the OFF position as long as the RCIC-system is not i

in the steam condensing mode. When a valve

-i (1E12-F052A or B) needs to be opened..the-4 circuit will be activated by changing the position of its division switch and then, sequentially,the control switch for that valve will be positioned for the desired valve motion. Because the circuit.is not

I 1.6.2 (continued)

~

activated, indiscriminant valve opening will not be possible.

1.6.3 Hot shorts might occur in the control circuits for valves 1E12-F087A and B in the event of a fire; however, each valve is in series with valves 1E12-F052A and B, respectively.

e e

e

-10a-

qualified to function for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following the. loss of the RCIC room (fire zone A.l.4) HVAC system and in the environment that will be present following a fire in zone A.1.1. (It should be noted that.the parameters for equipment qualification in zone A.1.4 are more severe for the high energy line break.) Therefore, even with the loss of the supply fan, cold shutdown could be-achieved using the Division 1 systems.

Also present in this zone are Division 1 and 2 cable trays. These trays are separated by a 3-hour fire barrier (see the Fire Protection Report figure FP-8).

The fire barrier is a concrete cantilever (a horizontal barrier). The Division 2 trays have been installed so that the outer edge of the tray is flush with the outer edge of the cantilever. Therefore, in the unlikely

) event of a fire in this zone at least one method to bring the reactor to cold shutdown would be available.

The performance goals for safe shutdown functions (Appendix R,Section III L) are assured by the systems listed below:

Performance Goal System Which Meets Goal

1. Reactor coolant RCIC (Div. 1) or LPCI makeup (Div. 2)

2. Reactor pressure SRV (Div. 1) or ADS control (Div. 2)

3. -Suppression pool RHR A (Div. 1) or RHR cooling (Div. 2) 4 .- Process variable Division 1 or 2 instru-indication mentation for:

=i

c. Conclusions Division 2 RHR system cables service valves necessar~Iy for safe shutdown by method #2. A fire in this zone would result in the loss of shutdown method #1 systems and the ,

RHR B system of method #2. Also, routed through this zone are the intake and exhaust ducts that provide cool air to the Division 2 switchgear room. A fire could result in a loss of cool air flow to the switchgear i

room making it difficult to shutdown the reactor via method #2 (see Section 1.3).

For a description of modifications necessary to satisfy the requirements of Appendix R see part d below and Section 3. ~ '

d. Modifications The Division 2 RHR valves need to be operated to bring the plant to cold shutdown only. Therefore, after hot shutdown has been achieved repairs

• can be made to the Division 2 cables to allow proceeding to cold shutdown.

Division 2 ventilation ducts will be surrounded with a fibrous insulating material produced by Transco, Inc.,

which will provide a 3-hour fire barrier./ Also all of the ductwork hangers and associated structural steel will be fireproof to withstand a 3-hour fire. Therefore, all of the Division 2 systems necessary to bring the plant to cold shutdown will function.

ASTM fire tests with air flowing inside the ducts will l

l l

• A spool of control wire (about 1300 ft. minimum) will be labeled and stored specifically for Division II control wire. replacement in this zone.