ML112230847

Proposed Tech Spec Change RTS-148,revising Group I Containment Isolation Signal from Reactor Vessel low-low to low-low-low Water Level

ML112230847
Person / Time
Site:	Duane Arnold
Issue date:	01/26/1983
From:	IES Utilities, (Formerly Iowa Electric Light & Power Co)
To:
Shared Package
ML112230845	List: ML112230844 ML112230847
References
NUDOCS 8303170460
Download: ML112230847 (13)

Text

PROPOSED CHANGE TO RTS-148 TO THE DUANE ARNOLD ENERGY CENTER TECHNICAL SPECIFICATIONS The holders of License DPR-49 for the Duane Arnold Energy Center propose to amend Appendix A (Technical Specifications) to said license by deleting current pages and replacing them with the attached new proposed pages. A list of the affected pages is included.

The changes revises the DAEC Appendix A Technical Specification for Group 1 Containment Isolation in two areas. First, the setpoint for Low Steam Pressure of Turbine Inlet is being revised from 880 psig to 850 psig. This setpoint is designed to limit the event initiated by main turbine pressure regulator failure. As evaluated in the DAEC UFSAR, Section 15.6.1, this transient is evaluated for MSIV closure initiating at 825 psig steam line pressure. The analytical limit of 125 psig below main steam line pressure of 14.5 950 psig for this setpoint is shown in the original DAEC FSAR in Figure Plant

10. This analytical limit of 825 psig was also confirmed by the DAEC Unique Licensing Supplement (NG-82-2962, December 30, 1982). The revised limit setpoint (of 850 psig) is generated by using this 825 psig analytical to and applying the GE suggested + 25 psig band for the Barksdale switches yield 850 psig. Further, although this setpoint is established on the basis as of pressure regulator failure, this transient is not a limiting event discussed in the DAEC UFSAR, Section 15.6.1.

The second change proposed in this application revises the DAEC Group 1 Isolation Group isolation on reactor vessel level from low-low to low-low-low reactor vessel level. The enclosed GE proprietary report, NEDE-30021, demonstrates the acceptability for this revision.

An additional change, identified on page 3.1-6, deletes reference to a 1035 psig trip function for MSIV Closure Scram with the mode switch not in Run. This change resolves a confusion in the technical specification because pressure this scram trip function is provided directly from the high reactor instruments identified on Table 3.1-1.

These modifications, in addition to provision of low-low-set our current safety/relief valve logic (which is being installed at DAEC during outage pursuant to 10 CFR 50.59) and other modifications restore the design at the time DAEC was licensed margin of the DAEC containment system intended for operation.

List of Affected Pages 3.1-6 3.2-5 3.2-5a 3.2-7 3.2-37 3.2-39 3.7-27 8303170460 830310 PDR ADOCK 05000331PDR P

DAEC-1

3. A main steam line isolation valve closure trip bypass is effective when the reactor mode switch is in the shutdown, refuel or startup positions. I

4. Bypassed when turbine first stage pressure is less than 192 psig or less than 30% of rated.

5. IRM's are bypassed when APRM's are on-scale and the reactor mode switch is in the run position.

6. When the reactor is subcritical and the reactor water temperature is less than 212*F, only the following trip functions need to be operable:

a. Mode switch in shutdown

b. Manual scram

c. High flux IRM and

d. Scram discharge volume high level - may be bypassed in the refuel shutdown modes for the purpose of resetting the scram.

e. APRM 15% flux 3.1-6

TABLE 3.2-A INSTRUMENTATION THAT INITIATES PRIMARY CONTAINMENT ISOLATION Minimum No. Number of of Operable Instrument Instrument Channels Valve Groups Channels Per Provided by Operated by Trip System (1) Instrument Trip Level Setting Design Signal Action (2) 2 (6) Reactor Low >+12" Indicated Level 4 2,3,4,5 A Water Level (3) (Sec. Cont., 3 E) 1 Reactor Low Pres < 135 psig 2 4 C sure (Shutdown Cooling Isolation)

Reactor Low-Low-Low At or above -139.5" 4 1 A 2

Water Level indicated level (8)

A m 2 (6) High Drywell < 2.0 psig 4 2,3,4,8,9* C~)

Pressure (Sec. Cont., 3 E)

< 3 X Normal Rated 4 1 B 2 High Radiation Main Steam Line Power Background Tunnel 2 Low Pressure Main > 850 psig (7) 4 1 B 1 .

Steam Line

< 140% of Rated 4 1 B 2 (5) High Flow Main Steam Line Steam Flow 4 1 B 2 Main Steam Line < 2000 F.

Tunnel/Turbine Bldg.

High Temperature

< 40 gpmd 2 5 D 1 Reactor Cleanup System High Diff.

Flow

• Group 9 valves isolate on high drywell pressure combined with reactor steam supply low pressure

TABLE 3.2-A INSTRUMENTATION THAT INITIATES PRIMARY CONTAINMENT ISOLATION (continued)

Minimum No. Number of of Operable Instrument Instrument Channels Valve Groups Channels Per Provided by Operated by Trip System (1) Instrument Trip Level Setting Design Signal Action (2) 130F 3 5 D 9

1 Reactor Cleanup Area Ambient High Temperature 1 Reactor Cleanup A 140F* 3 5 D I'1 Area Differential C-)

High Temperature Uo) 2 Loss of Main _ 10 in Hg Vacuum 4 1 B Condensor Vacuum 2 Reactor Low-Low At or above -38.5" 4 8 A Water Level indicated level (4)

• Note: The actual setpoint shall be A14F above the 100% operation ambient temperature conditions as determined by DAEC Plant Test Procedure.

DAEC-1

5. Two required for each steam line.

6. These signals also start SBGTS and initiate secondary containment isolation.

7. Only required in Run Mode (interlocked with Mode Switch).

8. Instrument setpoint corresponds to 18.5" above top of active fuel.

3.2-7

DAEC-1 adequate to prevent uncovering the core in the case of a break in the largest line assuming a 60 second valve closing time. Required closing times are less than this.

The low-low reactor water level instrumentation is set to trip when reactor water level is 119.5" (-38.5") above top of the active fuel. This trip initiates the HPCI and RCIC and trips the recirculation pumps. The low-low low reactor water level instrumentation is set to trip when the water level is 18.5" (-139.5") above the top of the active fuel. This trip activates the remainder of the CSCS subsystems, closes Group 7 valves, closed Main Steam Line Isolation Valves, Main Steam Drain Valves, Recirc Sample Valves (Group 1) and starts the emergency diesel generators. These trip level settings were chosen to be high enough to prevent spurious actuation but low enough to initiate CSCS operation and primary system isolation so that post accident cooling can be accomplished and the guidelines of 10 CFR 100 will not be exceeded. For large breaks up to the complete circumferential break of a 22-inch recirculation line and with the trip setting given above, CSCS initiation and primary system isolation are initiated in time to meet the above criteria. Reference Paragraph 6.5.4 FSAR.

3.2-37

DAEC-1 Temperature monitoring instrumentation is provided in the main steam line tunnel and turbine building to detect leaks in this area. Trips are provided on this instrumentation and when exceeded, cause closure of isolation valves. See Spec 3.7 for Valve Group. The setting is 200F for the main steam line tunnel detector. For large breaks, the high steam flow instrumentation is a backup to the temperature instrumentation.

High radiation monitors in the main steam line tunnel have been provided to detect gross fuel failure as in the control rod drop accident. With the established setting of 6 times normal background, and main steam line isolation valve closure, fission product release is limited so that 10 CFR 100 guidelines are not exceeded for this accident. Reference Subsection 14.6.2 of the FSAR.

Pressure instrumentation is provided to close the main steam isolation valves in RUN Mode when the main steeam line pressure drops below 850 psig.

The Reactor Pressure Vessel thermal transient due to an inadvertent opening of the turbine bypass valves when not in the RUN Mode is less severe than the loss of feedwater analyzed in Subsection 14.5 of the FSAR, therefore, closure of the Main Steam Isolation valves for thermal transient protection when not in RUN Mode is not required.

3.2-39

DAEC-1 qW NOTES FOR TABLE 3.7-3

1. Isolation Signals are as follows:

Group 1:

The valves in Group 1 are closed upon any one of the following conditions:

1. Reactor vessel low-low-low water level.

2. Main steam line high radiation.

3. Main steam line high flow.

4. Main steam line tunnel high temperature.

5. Low main steam line pressure at turbine inlet (run mode only).

6. Main condenser low vacuum.

Group 2:

The valves in Group 2 are closed upon any of the following conditions:

1. Reactor vessel low water level.

2. High drywell pressure.

3.7-27

GENERAL ELECTRIC COMPANY AFFIDAVIT I, Glenn G. Sherwood, being duly sworn, depose and state as follows:

1. I am Manager, Safety and Licensing Operation, General Electric Company, and have been delegated the function of reviewing the information described in paragraph 2 which is sought to be withheld and have been authorized to apply for its withholding.

2. "Low-Low Set Relief Logic System and Lower MSIV Water Level Trip for The Duane Arnold Energy Center," January 1983 (NEDE-30021).

3. In designating material as proprietary, General Electric utilizes the definition of proprietary information and trade secrets set forth in the American Law Institute's Restatement Of Torts, Section 757.

This definition provides:

"A trade secret may consist of any formula, pattern, device or compilation of information which is used in one's business and which gives him an opportunity to obtain an advantage over competitors who do not know or use it.... A substantial element of secrecy must exist, so that, except by the use of improper means, there would be difficulty in acquiring informa tion.... Some factors to be considered in determining whether given information is one's trade secret are: (1) the extent to which the information is known outside of his business; (2) the extent to which it is known by employees and others involved in his business; (3) the extent of measures taken by him to guard the secrecy of the information; (4) the value of the information to him and to his competitors; (5) the amount of effort or money expended by him in developing the information; (6) the ease or difficulty with which the information could be properly acquired or duplicated by others."

4. Some examples of categories of information which fit into the definition of proprietary information are:

a. Information that discloses a process, method or apparatus where prevention of its use by General Electric's competitors without license from General Electric constitutes a competitive economic advantage over other companies;

b. Information consisting of supporting data and analyses, includ ing test data, relative to a process, method or apparatus, the application of which provide a competitive economic advantage, e.g., by optimization or improved marketability;

c. Information which if used by a competitor, would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality or licensing of a similar product;

d. Information which reveals cost or price information, production capacities, budget levels or commercial strategies of General Electric, its customers or suppliers;

e. Information which reveals aspects of past, present or future General Electric customer-funded development plans and programs of potential commercial value to General Electric;

f. Information which discloses patentable subject matter for which it may.be desirable to obtain patent protection;

g. Information which General Electric must treat as proprietary according to agreements with other parties.

5. In addition to proprietary treatment given to material meeting the standards enumerated above, General Electric.customarily maintains in confidence preliminary and draft material which has not been subject to complete proprietary, technical and editorial review.

This practice is based on.the fact that draft documents often do not appropriately reflect all aspects of a problem, may contain tentative conclusions and may contain errors that can be corrected during normal review and approval procedures. Also, until the final document is completed it may not be possible to make any definitive determination as to its proprietary nature. General Electric is not generally willing to release such a document to the general public in such a preliminary form. Such documents are, however, on occasion furnished to the NRC staff on a confidential basis because it is General Electric's belief that it is in the public interest for the staff to be promptly furnished with significant or potentially significant information. Furnishing the document on a confidential basis pending completion of General Electric's internal review permits early acquaintance of the staff with the information while protecting General Electric's potential proprietary position and permitting General Electric to insure the public documents are technically accurate and correct.

6. Initial approval of proprietary treatment of a document is made by the Subsection Manager of the originating component, the man most likely to be acquainted with the value and sensitivity.of the information in relation to industry knowledge. Access to such documents within the Company is limited on a "need to know" basis and such documents at all times are clearly identified as proprietary.

7. The procedure for approval of external release of such a document is reviewed by the Section Manager, Project Manager, Principal Scientist or other equivalent authority, by the Section Manager of the cognizant Marketing function (or his delegate) and by the Legal Operation for technical content, competitive effect and determination of the accuracy of the proprietary designation in accordance with the standards enumerated above. Disclosures outside General Electric are generally limited to regulatory bodies, customers and potential customers and their agents, suppliers and licensees only in accord ance with appropriate regulatory provisions or proprietary agreements.

8. The document mentioned in paragraph 2 above has been evaluated in accordance with the above criteria and procedures and has been found to contain information which is proprietary and which is customarily held in confidence by General Electric.

9. The information contained herein is the result of extensive analyses performed at.considerable cost to the General Electric Company. The development and verification of these methods, as well as their application and execution cost in excess of $12 million.

STATE OF CALIFORNIA )

COUNTY OF SANTA CLARA )

Glenn G. Sherwood, being duly sworn, deposes and says:

That he has read the foregoing affidavit and the matters stated therein are true and correct to the best of his knowledge, information, and belief.

Executed at San Jose, California, this 26 day of January , 1983 Glenn G. 'Sherwood General Electric Company Subscribed and sworn before me this 26 day of January 1983.

OrIKiCIAL SEAL SKAR EN S. VOGELHUBER SNOTARY PUBLIC.CALIFORNIA SANTA CLARA COUNTY 6 NOTARY PUBLIC, STATE P CALIFORNIA My Commission Expires Dec. 21,1984 HTW:rf/G01245 1/24/83 S 25 i

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NRCFORM 190B (9-80)

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