L-88-017, Response Clarification to Generic Letter 88-017: Difference between revisions
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# | {{Adams | ||
| number = ML13228A264 | |||
| issue date = 08/13/2013 | |||
| title = Response Clarification to Generic Letter 88-017 | |||
| author name = Hruby R | |||
| author affiliation = Tennessee Valley Authority | |||
| addressee name = | |||
| addressee affiliation = NRC/Document Control Desk, NRC/NRR | |||
| docket = 05000390, 05000391 | |||
| license number = CPPR-0092, NPF-090 | |||
| contact person = | |||
| case reference number = GL-88-017 | |||
| document type = Letter type:L | |||
| page count = 4 | |||
}} | |||
=Text= | |||
{{#Wiki_filter:Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 August 13, 2013 10 CFR 50.4 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating License No. NPF-90 Construction Permit No. CPPR-92 NRC Docket Nos. 50-390 and 50-391 | |||
==Subject:== | |||
WATTS BAR NUCLEAR PLANT (WBN) UNITS I AND 2 - GENERIC LETTER (GL) 88 RESPONSE CLARIFICATION | |||
==References:== | |||
: 1. TVA letter to NRC dated February 9, 1998, "Watts Bar Nuclear Plant (WBN) | |||
Unit 1 - 10 CFR 50.59(b)(2), Changes, Tests and Experiments Summary Report" | |||
: 2. NRC letter to TVA dated March 8, 1995, "Watts Bar Unit 1 - Revised Response to Generic Letter 88-17 Regarding Loss of Decay Heat Removal (TAC M69792)" | |||
: 3. TVA letter to NRC dated February 7, 1995, "Watts Bar Nuclear Plant (WBN) | |||
Unit 1 and 2 - Generic Letter 88-17, Loss of Decay Heat Removal - Revised Response to Item 4 (TAC No. M69792)" | |||
This letter revises one of the two methods TVA will use to provide reactor coolant system (RCS) narrow range water level indications during reduced inventory conditions. | |||
In the revised response to GL 88-17 (Reference 3), TVA stated the following: | |||
"NarrowRange Level Indication - Two independent,RCS waterlevel indications will be used whenever the RCS is in a reduced inventory condition. An ultrasonic level measurement system (ULMS) and a differential pressure type level instrument loop will be utilized. Both instruments will have a range of indicationthat encompasses the inside diameter of the hot leg pipe. Indication with visible and audible alarms will be provided in the main control room for the differential pressure type level instrument loop. The ULMS | |||
U.S. Nuclear Regulatory Commission Page 2 August 13, 2013 will have indication with visible and audible alarm capability in the Main Control Room on the emergency response facility data system computer." | |||
NRC accepted this approach in Reference 2. | |||
However, in 1997, Unit 1, under 10 CFR 50.59 (Summary Report provided by Reference 1), switched from the ULMS to a portable reactor vessel level monitoring system (Mansell Level Monitoring System [MLMS]). The MLMS utilizes redundant pressure transducers mounted at a reference location (pressurizer vent and reactor head vent) and at a liquid head location (loop #1 crossover leg drain line). The pressure information from these points is transmitted to the Control Room, processed by a computer dedicated to the MLMS, and displayed to the Control Room operators in FEET and INCHES to a resolution of 0.1 inches of water. The display system also provides an operator interface where the required information can be entered to set the proper zero range, level alarm setpoints, temperature, and boron concentration. This system has been proven to be a more accurate and reliable system than the ultrasonic system. | |||
For WBN Unit 2, instead of completing the originally planned ULMS, TVA will utilize the same type of MLMS as Unit 1. The MLMS is installed in the Control Room prior to going into reduced inventory operations. Installation, use, and removal of the MLMS is performed in accordance with General Operating Procedure GO-10, "Reactor Coolant System Drain and Fill Operations." The MLMS provides narrow range level indication and alarms in the Control Room. The alarm setpoints for the MLMS are set in accordance with GO-10 and are dependent on the plant evolution in progress. This change is reflected in Amendment 110 of the Unit 2 Final Safety Analysis Report (FSAR) being submitted by separate correspondence. | |||
The enclosure provides the commitment made in this letter. | |||
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 1 3 th day of August, 2013. | |||
If you have any questions, please contact me at (423) 365-1260 or Gordon Arent at (423) 365-2004. | |||
Respectfully, Raymond A. Hruby, Jr. | |||
General Manager, Technical Services Watts Bar Unit 2 | |||
U.S. Nuclear Regulatory Commission Page 3 August 13, 2013 | |||
==Enclosure:== | |||
: 1. List of Commitments cc (Enclosure): | |||
U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Resident Inspector Unit 1 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 NRC Resident Inspector Unit 2 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 | |||
WATTS BAR NUCLEAR PLANT (WBN) UNITS I AND 2 GENERIC LETTER (GL) 88 RESPONSE CLARIFICATION LIST OF COMMITMENTS | |||
: 1. Each WBN unit will update their respective Safety Analysis Report (i.e., UFSAR for Unit 1 and FSAR for Unit 2) to reflect this different means of providing two different monitoring systems.}} |
Latest revision as of 04:24, 20 March 2020
ML13228A264 | |
Person / Time | |
---|---|
Site: | Watts Bar ![]() |
Issue date: | 08/13/2013 |
From: | Hruby R Tennessee Valley Authority |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
GL-88-017 | |
Download: ML13228A264 (4) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 August 13, 2013 10 CFR 50.4 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating License No. NPF-90 Construction Permit No. CPPR-92 NRC Docket Nos. 50-390 and 50-391
Subject:
WATTS BAR NUCLEAR PLANT (WBN) UNITS I AND 2 - GENERIC LETTER (GL) 88 RESPONSE CLARIFICATION
References:
Unit 1 - 10 CFR 50.59(b)(2), Changes, Tests and Experiments Summary Report"
- 2. NRC letter to TVA dated March 8, 1995, "Watts Bar Unit 1 - Revised Response to Generic Letter 88-17 Regarding Loss of Decay Heat Removal (TAC M69792)"
Unit 1 and 2 - Generic Letter 88-17, Loss of Decay Heat Removal - Revised Response to Item 4 (TAC No. M69792)"
This letter revises one of the two methods TVA will use to provide reactor coolant system (RCS) narrow range water level indications during reduced inventory conditions.
In the revised response to GL 88-17 (Reference 3), TVA stated the following:
"NarrowRange Level Indication - Two independent,RCS waterlevel indications will be used whenever the RCS is in a reduced inventory condition. An ultrasonic level measurement system (ULMS) and a differential pressure type level instrument loop will be utilized. Both instruments will have a range of indicationthat encompasses the inside diameter of the hot leg pipe. Indication with visible and audible alarms will be provided in the main control room for the differential pressure type level instrument loop. The ULMS
U.S. Nuclear Regulatory Commission Page 2 August 13, 2013 will have indication with visible and audible alarm capability in the Main Control Room on the emergency response facility data system computer."
NRC accepted this approach in Reference 2.
However, in 1997, Unit 1, under 10 CFR 50.59 (Summary Report provided by Reference 1), switched from the ULMS to a portable reactor vessel level monitoring system (Mansell Level Monitoring System [MLMS]). The MLMS utilizes redundant pressure transducers mounted at a reference location (pressurizer vent and reactor head vent) and at a liquid head location (loop #1 crossover leg drain line). The pressure information from these points is transmitted to the Control Room, processed by a computer dedicated to the MLMS, and displayed to the Control Room operators in FEET and INCHES to a resolution of 0.1 inches of water. The display system also provides an operator interface where the required information can be entered to set the proper zero range, level alarm setpoints, temperature, and boron concentration. This system has been proven to be a more accurate and reliable system than the ultrasonic system.
For WBN Unit 2, instead of completing the originally planned ULMS, TVA will utilize the same type of MLMS as Unit 1. The MLMS is installed in the Control Room prior to going into reduced inventory operations. Installation, use, and removal of the MLMS is performed in accordance with General Operating Procedure GO-10, "Reactor Coolant System Drain and Fill Operations." The MLMS provides narrow range level indication and alarms in the Control Room. The alarm setpoints for the MLMS are set in accordance with GO-10 and are dependent on the plant evolution in progress. This change is reflected in Amendment 110 of the Unit 2 Final Safety Analysis Report (FSAR) being submitted by separate correspondence.
The enclosure provides the commitment made in this letter.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 1 3 th day of August, 2013.
If you have any questions, please contact me at (423) 365-1260 or Gordon Arent at (423) 365-2004.
Respectfully, Raymond A. Hruby, Jr.
General Manager, Technical Services Watts Bar Unit 2
U.S. Nuclear Regulatory Commission Page 3 August 13, 2013
Enclosure:
- 1. List of Commitments cc (Enclosure):
U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Resident Inspector Unit 1 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 NRC Resident Inspector Unit 2 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381
WATTS BAR NUCLEAR PLANT (WBN) UNITS I AND 2 GENERIC LETTER (GL) 88 RESPONSE CLARIFICATION LIST OF COMMITMENTS