ML20133F529

Forwards Response to 850208 Request for Addl Info Re Conformance W/Rev 3 to Reg Guide 1.97.RCS Flow Deleted as Type a Variable Upon Reevaluation of Planned Manual Actions Taken in Emergency Procedures

ML20133F529
Person / Time
Site:	North Anna
Issue date:	08/02/1985
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Butcher E, Harold Denton Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, RTR-REGGD-01.097, RTR-REGGD-1.097 85-094B, 85-94B, NUDOCS 8508080322
Download: ML20133F529 (5)

Text

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August 2, 1985 VIRGINIA POWBt Mr. Harold R. Denton, Director Serial No. 85-094B Office of Nuclear Reactor Regulation E&C/BMc:acm Attn:

Mr. Edward J. Butcher, Acting Chief Docket Nos. 50-338 Operating Reactors Branch No. 3 50-339 Division of Licensing License Nos. NPF-4 U. S. Nuclear Regulatory Commission NPF-7 Washington, D. C. 20555 Gentlemen:

VIRGINIA POWER NORTH ANNA POWER STATION, UNITS 1 AND 2 CONFORMANCE WITH REGULATORY GUIDE 1.97 Virginia Power letters, Serial No.84-094, dated May 10, 1985 and Serial No.

85-094A, dated July 5,

1985, provided a partial response to your 1'

of February 8,

1985, which requested additional information ning conformance with Regulatory Guide 1.97, Revision' 3.

The a,

.iment to this letter provides responses for the remaining two items.

If you have any questions, or need additional information to complete your review, please contact us.

Very truly yours, Q W. L. Stewart Attachment cc:

Dr. J. Nelson Grace Regional Administrator Region II Mr. M. W. Branch NRC Resident Inspector North Anna Power Station g

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85080803228508h2ADOCK 0500 338 hDR PDR

NORTH ANNA POWER STATION REGULATORY GUIDE 1.97 RESPONSE TO NRC LE' ITER DATED FEBRUARY 8, 1985 NRC letter, dated February 8, 1985, on conformance with Regulatory Guide 1.97 identified sixteen open items and requested a Virginia Power response to each item.

Responses to fourteen of these items were provided in Virginia Powee letters Serial No.85-094, dated May 10, 1985, and Serial No. 85-094A, dated July 5, 1985. The remaining two items are addressed below.

Item 1 RCS flow -- the licensee should upgrade this instrumentation to Category 1 requirements (Section 3.2).

Virginia Power Response Upon reevt.luation of plcnned manual actions taken in emergency procedures,: RCS flow has been deleted as a Type A variable for North Anna Power Stat:.on, Originally RCS flow was intended to be used to provide a qualified means of verifying whether the Reactor Coolant Pumps were operating /not operating.

This function is also identified as variable D-10, RCP status, in.the Virginia Power submittal (Serial No. 054) of January 31, 1984.

By definition, a Type A variable provides primary information which is

"... essantial for the direct accomplishment of the specified safety functions; it does not include those variables that are associated with contingency actions that may also be identified in written procedures.

Primary information is needed to permit the Control Room operating personnel to take the specified manually controlled actions for which no automatic control is provided and that are required for safety systems to accomplish their safety functions for the design basis accident event."

(R. G.

1.97, Rev. 3).

RCP status is associated with contingency actions in the Emergency Operating Procedures, and as such, there is no basis for requiriag either RCP status or RCS flow to be Type A variables.

Item 3 Radiation level in circulating primary coolant -- the licensee should provide the information required by Section 6.2 of NUREG-0737, Supplement No.1 for this variable (Section 3.3).

Virginia Power Response Regulatory Guide 1.97 recommends monitoring this variable for the purpose of detecting fuel cladding failure. The Containment High Range Radiation Monitoring System (CHRRMS; RM-RMS-165,-166,-265,-266) which is qualified per Reg. Guide 1.97 would be used for this purpose. The CHRRMS has been identified by Westinghouse as a method of determining the extent of fuel I

L damage for any accident involving a breach of the reactor coolant system to the containment atmosphere.

Additionally, the Core Exit Thermocouples have been identified by Westinghouse as a method of determining fuel cladding failure. This system is scheduled to be upgraded to meet Reg Guide 1.97 by the completion of the second refueling outage after July 1985 as identified in our letter, Serial No. 447, dated August 3, 1984. The system can be used to monitor changes in temperature for any region of the reactor core.

' Core exit temperature can be used as an indication of potential fuel cladding damage. The thermocouples will be able to detect temperatures above acceptable limits, which would be indicative of possible fuel cladding failure.

The two methods described above both meet the qualifications required by Reg Guide 1.97 and provide diverse techniques for detecting fuel cladding failure.

The backup method, which will be used to sample and obtain actual radioactivity concentration measurements, is the Post Accident Sampling System (PASS), which is qualified to NUREG-0737 requirements.

PASS has the capability to analyze primary coolant radioactivity, providing a trending capability for determining the degree of fuel cladding failure.

PASS meets the range requirements specified in Reg.

Guide 1.97.

Virginia Power believes that the combination of these systems meets the intent of Reg Guide 1.97 for the C-2 variable and is consistent with the Westinghouse Emergency Response Guidelines for this variable.

The information relative to Section 6.2 of NUREG-0737, Supplement No.

1 is provided in Tables 1 and 2.

I t

Table 1

1. System Upgraded Core Exit Containment High Range Thermocouples Monitor System (CHRRMS)

(Two groups of 25 (RM-RMS-165,-166, thermocouples monitor

-265,-266) the 4 core quadrants)

2. Instrument 200 to 2300 degrees F 1 to 1E7 R/hr Range

3. Environmental System will be install-Monitors qualified to Qualification ed to meet Reg Guide harsh environment.

1.97 Category 1 Readout in Control Room Requirements

4. Seismic All equipment seist. cal-All equipment seismical-Qualification ly qualified ly qualified

5. Quality Category 1 Category 1 Assurance

6. Redundancy 25 thermocouple Each monitor meets inputs to two separate redundancy criterion channels (A and B) which meet redundancy criterion

7. Power Supply 1E 1E

8. Location Readouts in Control Room. Readouts in Control Room.

Thermocouples in 3CS in Monitors in Containment Containment Building Building

J l

Table 2 1.

System:

Post Accident Sampling System (Sentry) 2.

Instrument 1/2 times Tech Spec Limit to 100 times Tech Spec Range:

Limit 3.

Environmental The panel is environmentally qualified consistent Qualification:

with NUREG-0737 for conditions expected post-accident and is accessible during postulated i

events.

4.

Seismic Partial. Sample lines are seismically qualified Qualification from sample point to outside containment i

isolation valves.

5.

Quality Category 3 Assurance:

6.

Redundancy:

None 7.

Power Supply:

Non-1E 8.

Location:

Control Panel in Service Bldg. Elev.

294'-0";11guid sampler panel in Aux.

Bldg. Elev. 271'-0".

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