ML19282C737
| ML19282C737 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 04/27/1979 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| TAC-64359, NUDOCS 7904300269 | |
| Download: ML19282C737 (6) | |
Text
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APPENDIX F F
15830 SM U D
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L April 27, 1979 Z
Mr. Harold R. Denton Director Office of Nuclear Reactor Regulation
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Washington, D. C.
20555 Re: Rancho Seco Nuclear Station Docket No. 50-312
Dear Mr. Denton:
In response to the staff safety concerns identified as items a. through
- e. on page 1-7 of the ONRR Status Report to the Commission of April 25, 1979, the Sacramento Municipal Utility District proposes the following actions:
(a) Upgrade of the timeliness and reliability of delivery from the Auxiliary Feedwater System by carrying out items 1 through 9 identified in enclosure 1.
(b) Develop and implement operating procedures for initiating and controlling auxiliary feedwater independent of ICS control.
(c) Implement a hard-wired control-grade reactor trip on loss of main feedwater and/or turbine trip.
(d) Complete analyses for potential small breaks and develop and implement operating instructions to define operator action.
(c) The District will provide for one Senior Licensed Operator assigned to the control room who has had TMI-2 training on the B&W simulator.
Rancho Seco will be shutdown on April 28, 1979 and will not be restarted until item a. through e. above are completed.
The District further cormiits to the following additional actions for improvement and in assuring safety that is related to items a. through
- e. in ONRR Status Report of April 25, 1979:
790430 o c26 9
Mr. Harold R. Denton 2
April 27, 1979 (a) The District will provide a proposed s hedule for implementation of identified design modifications which specifically relate to items 1 through 9 of enclosure 1 and would significantly improve safety.
(b) The failure mode and effects analysis of ICS is underway with high priority by B&W and will be submitted as soon as practi-cable.
(c) The hard-wired trips will be revised to safety grade.
(d) A more complete description of the transient analyses is provided in enclosure 2 entitled " Guidelines for the Developnent of Operational Procedures for Safe Management of Small Breaks in the Reactor Coolant System Pressure Bounda ry. "
(e) The District will continue operator training and drilling and will have a minimum of two licensed operators per shift with TMI-2 simulator training at B&W by June 1, 1979. There-after at least one licensed operator with TMI-2 simulator training at B&W will be assigned to the Control Room. All training of licensed personnel will be completed by June 28, 1979.
The District is confident that these steps will meet your Staff concerns and provide additional assurance of public safety.
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. J. Mattimoe Assistant General Manager and Chief Engineer 9
ENCLOSURE (1)
Auxiliary Feedwater System Upgrade 1.
Review procedures, revise as necessary and conduct training to ensure timely and proper starting of motor driven auxiliary feedwater (AFW) pump (s) from vital AC buses upon loss of offsite power.
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To assure that AFW will be aligned in a timely manner to inject on all 5
2.
AFW demand events when in the surveillance test mode, procedures will -
be implemented and training conducted to provide an operator at the necessary valves in phone communications with the control room during the surveillance mode to carry out the valve alignment changes upon AFW demand events.
3.
Procedures will be developed and implemented and training conducted to provide for control of steam generator level by use of safety grade AFW bypass valves in the event that ICS steam generator level control fails.
4.
Verification that Technical Specification requirements of AFW capacity are in accordance with the accident analysis will be conducted. Pump capacity with mini flow in service will also be verified.
5.
Modifications will be made to provide verification in the control room of AFW flow to each steam generator.
6.
Review and revise, as necessary, the procedures and training for pro-viding alternate sources of water to the suction of the AFW pumps.
ENCLOSURE (1)
_2 7.
Design review and modification, as necessary, will be conducted to provide control room annunciation for all auto start conditions of the AFW system.
8.
Procedures will be developed and implemented and training conducted to provide guidance for timely operator verification of any automatic initiation of AFW.
9.
Verification will be made that the air operated level control valves (a)
Fail to the 50% open position upon loss of electrical power to the electrical to pressure converter, and (b) Fail to the 100% open position upon loss of service air. The AFW bypass valves are safety grade.
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8
April 27, 1979 ENCLOSURE (2)
GUIDELINES FOR THE DEVELOPMENT OF OPERATIONAL PROCEDURES FOR SAFE MANAGEMENT OF SMALL BREAKS IN THE REACTOR COOLANT SYSTEM PRESSURE BOUNDARY Operational guidelines will be prepared for the safe handling of small breaks as an extension of and addition to previously issued guidelines and IE Bulletin 79-05A. These guidelines will include provisions for operator recognition of small breaks and discrimina-tion of other accidents which might produce similar symptoms.
The guidelines will include expected system response insofar as required to assure effective operator understanding and action.
The guidelines will include necessary precautions and will describe those actions which the operator must take to assure safe management and mitigation of small break events, including natural circulation cooling where it is predicted to occur in the course of the accident.
These guidelines will specifically cover cases in which RCS stabili-zation will occur with a partially filled reactor coolant system for both the case with the reactor coolant pumps on and the reactor coolant pumps off. Delay in the initiation of auxiliary feedwater up to 20 minutes will be considered. System conditions covered will assume availability of ECCS systems at full design flow in the event that auxiliary feedwater is not available or with single failure in the ECCS systems in the event that auxiliary feedwater is available.
ENCLOSURE (2) April 27, 1979 The guidelines will be based on existing analyses and by specific additional computer calculations. These calculations will be per-formed to define system response to re-start of reactor coolant pumps in a partially filled system and response of the partially filled system to re-start of auxiliary feedwater.
These guidelines will be developed by B&W and revie.wed by the NRC staff in time for implementation of the corresponding procedures by the Sacramento Municipal Utility District on or before May 15, 1979.
APRIL 27, 1979 9
4 e
APPENDIX G Florida Powe.r m.
8 L Gnifin. P E Sewt vice Presdont Eamnaeong & Con <'ruct'on May 1,1979 Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Crystal River Unit 3 Docket No. 50-302 Operating License DPR-72
Dear Mr. Denton:
In response to Staff safety concerns id itified as items a. through e.
on page 1-7 of the ONRR Status Report t-the Commission of April 25, 1979, Florida Pvwer Corporation propose to implement the following interim actions until further analysis of these concerns can be completed:
(a)
Upgrade of the timeliness and reliability of delivery from the Emergency Feedwater System by carrying out items 1 through 9 identified in Enclosure 1.
(b)
We have developed and implemented operating procedures for initiating and controlling emergency feedwater independent of ICS control.
(c)
Implement a hard-wired cont rol-grade reactor trip en loss of main feedwater or turbine trip.
(d)
Complete analyses for potential small breaks and develop and implement operating instructions to define operator action.
(e)
All Control Room operators have completed TMI-2 training on the B&W simulator.
Crystal River Unit 3 is shutdown for maintenance and refueling and Florida Power Corporation has conmitted in our April 27,19/9, letter to you to resolve and implement items a. through c. prior to startup which is currently scheduled for June 1,1979.
320; Thirty fourth Street South. P O Bcx 140c St Peterst,urg Fiemu JJU3 3:3 N O S151
Harold R. Denton Page 2 May 1, 1979 l
l FPC further commits to the following ongoing /long term actions for improvement 'and~ assuring safety at Crystal River Unit 3:
(a)
The failure mode and effects analysis of ICS is underway with high priority by B&W and will be submitted as soon as practicable.
(b)
Upon completion of a detailed design and supporting analy-sis, the hard-wired trip will be revised to a safety grade system.
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(c)
Modifications will be made to provide verification in the control room of EFW flow to each steam generator.
(d)
A more complete description of the small breaks transient analyses is provided in Enclosure 2, entitled " Guidelines for the Development of Operational Procedures for Safe Management of Small Breaks in the Reactor Coolant System Pressure Boundary."
(e)
We will continue operator training and drilling of response procedures as a part of our ongoing program to assure the high state of readiness and safe operation at CR3.
We are confident that this action will meet your Staff concerns and pro-vide additional assurance of the health and safety of the public.
Very truly 3' furs,
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~ i B. L. Griffin PYBekcS01 D65 Enclosures
STATE OF FLORIDA COUNTY OF PINELLAS B.L. Griffin states that he is the Senior Vice President, Engineering and Construction, Florida Power Corporation; that. he is authorized on the part of said company to sign and file with the Nuclear Regulatory Commission the information attached hereto; and that all such statements made and natters set forth therein are true and correct to the best of his knowledge, information and belief.
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B. L. Gri f fin Subscribed and sworn to before ae, a Notary Public in and for the State and County above r.amed, this 1st day of May,1979.
Notary Publicj '
f Notary Public, State of Florida at Large, My Commission Expires: July 25, 1980 (Notary 1 012) e
ENCLOSURE (1)
May 1, 19,9 AUXILIARY FEEDWATER SYSTEM UPGRADE 1.
Review procedures, revise as necessary and conduct training to en-sure timely and proper starting of inotor driven emergency feedwater (EFW) pump from engineered safeguards bus A upon loss of offsite power.
2.
To assure that EFW will be aligned in a timely manner to inject on all EFW demand events when in the surveillance test mode, proce-dures will be implemented, and training conducted to pruvide an operator at the necessary valves in corm:unication with the control room during the surveillance mode to carry out the valve alignment char.ges upon EFW demand events.
3.
Emergency feedwater bypass valves are normally in the open posi-s-
tion. Procedures have been developed and implemented to require the operator to take control of these valves upon failure of the ICS steam generator level control.
If the ICS level control dnes not fail the operator will close the bypass valves.
Those va lves in the EFW system not locked in position are verified to be in the proper position on a daily basis. Training will be conducted on these revised procedures prior to June 1,1979.
4 The EFW pumps will be verified operable in accordance with the CR#3 Technical Specifications and Surveillance Procedures.
5.
Review and revise, as necessary, the procedures and training for providing alternate sources of water to the suction uf the LFW pumps.
6.
Remove the interlock which prevents.the turbine-driven emergency feedwater pump operation when the cotor driven emergency feedwater pump is running.
7.
In event emergency feedwater is necessary and of fsite power is available, an auto start signal will be provided to the motor driven emergency feedwater pump.
8.
Design review and modification, as necessary, will be conducted to provide control room annunciation for auto start conditions of the EFW system.
9.
Verification has been imde that the air operated level control valves (a) fail to the 50% npen position upon loss of power t o the electrical / pressure converter, and (b) tail to the as is po,ition upon loss of instrument air and electrical power to the air lock.
At full load these valves are in.the full (100%) open positions and at icw power levels (below 15%) they are partially open controlling flow.
If these valves were to fail closed, feedwater flow would be controlled using the EFW bypass valves as described in Item 3 above.
PYBekcS01(065)
ENCLOSURE (2)
May 1, 1979 GUIDELINES FOR THE DEVELOPMENT OF OPERATIONAL PROCEDURES FOR SAFE MANAGEMENT OF SMALL BREAKS IN THE REACTOR COOLANT SYSTEM PRESSURE BOUNDARY Operational guidelines will be prepared for the safe handling of small breaks as an extension of and addition to previously issued guidelines and IE Bulletin 79-05A. These guidelines will include provisions for Operator recognition of small breaks and discrimination of other acci-dents which might produce similar symptoms.
The guidelines will include exp'ected system response. insofar as required I
to assure effective operator understanding and action. The guidelines will include necessary precautions and will describe those actions which the operator must take to assure safe nanagement and mitigation of small break events, inc.luding natural circulation cooling where it is predict-ed to occur in the course of the accident.
These guidelines will specifically cover cases in which RCS stabiliza-tion will occur with a partially filled reactor coolant system for both the case with the reactor coolant pumps on and the reactor coolant pumps off. Delay in the initiation of auxiliary feedwater up to 20 minutes will be considered. System conditions covered will assume availability of ECCS systems at full design flow in the event that auxiliary feed-water is not available or with single failure in the ECCS systems in the event that auxiliary feedwater is available.
The guidelines will be based on existing analyses and by specific addi-tional computer calculations. These calculations will be performed to define system response to restart of reactor coolant pumps in a partial-ly filled system and response of the partially filled system to restart of auxiliary feedwater.
These guidelines will be devloped by B&W and reviewed by the NRC staff in time for implementation of the corresponding procedures by Florida Power Corporation on or before startup.
PYBekcS01(065)