ML18043A995
| ML18043A995 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 08/10/1979 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 7909110017 | |
| Download: ML18043A995 (5) | |
Text
consumers Power company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201
- Area Code 517 788-0550
- August 10, 1979 Mr James G Keppler Office of Inspection and Enforcement Region III US Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - IE BULLETIN 79-06B RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION DATED JULY 25, 1979 Consumers Power Company's response to your request for additional information regarding IE Bulletin 79-06B (Review of Operational Errors and System Misalign-ments Identified During the Three Mile Island Incident) is as follows:
Item 2.a State the procedure and instruments used to permit recognition of void formation in forced circulation mode and state the procedure and instruments to be used in natural circulation mode.
In addition we request that you revise procedures as appropriate to include instructions on the use of information from the source range neutron detectors and in-core thermocouples to recognize void_f'ormation.
Response
The procedures for forced circulation mode are:
EOP 10 (Rev A) - Loss of'Coolant Accident EOP 13 - Primary Coolant System Depressurization The instruments used for recognition of void formation in forced circulation mode are:
Core Outlet Thermocouples Steam Generator 6P Detectors Core 6T
The procedure for natural circulation mode is:
ONP Natural Circulation The instruments used for recognition of void formation in natural circulation are:
Core Outlet Thermocouples Core liT 2
Consumers Power Company will revise the natural circulation procedure to include the following verifications of natural circulation (as recommended by our vendor) by the end of the upcoming refueling outage:
- Loop liT at less than normal full power liT.
- Tc controllable (constant or decreasing).
Tri not steadily increasing.
Core exit thermocouples following Th RTDs.
By the end of the upcoming refueling outage we will include the following parameter in both procedures to be monitored for void formation:
- Source range neutron detectors and in-core thermocouples behaving predict-ably (ie, not displaying erratic behavior).
Item 3 It is our position, that unless a line is needed for safety features or cooling capability, it should be isolated either manually or automatically upon initiation of safety injection.
For any lines not isolated upon automatic initiation of safety injection provides justification that the line is needed to prevent degrada-tion of needed safety features or cooling capability.
Provide your schedule for completion of the modification to the containment cooling water isolation function described in your letter of June 5, 1979.
Pro-vide assurance that the modification will be done as soon as practicable but no later than your summer 1979 refueling outage.
Response
Consumers Power Company will revise the LOCA procedure to include manual isolation of containment when primary system pressure drops below 1250 psig (actual HPSI flow initiation as described in our August 2, 1979 response to IE Bulletin 79-06C).
Containment isolation will normally be reset when safety injection is reset.
Safety injection reset is discussed more thoroughly in Item 6.b below.
This pro-cedure will be revised by September 30, 1979*
The component cooling water (CCW) modification will be completed by the end of the upcoming refueling outage except for the redundant level sensor in the CCW surge tank.
The system will be operable even without the redundant level sensor.
This.
sensor will be installed as soon as possible after receipt.
The modification will
3 provide for CCW isolation to the primary coolant pumps (PCPs) when either a combination of containment high pressure (-27 psig) and safety injection actu-ation occurs or when a combination of containment high pressure (-27 psig) and CCW*surge tank low level occurs.
Item 4 We request that a licensed operator who has direct responsibility for control and operation of all main and auxiliary feedwater systems be in the main control room at all times.
We also request that the operator assigned to this function will, at the time of the transient requiring such action, take immediate control of the main and auxili.ary feedwater systems, with no other concurrent responsi-bilities, until the steam generator levels return to a stable condition.
Response
Consumers Power Company has two (2) licensed operators in the control room at all times as per the requirements of IE Bulletin 79-06C.
Procedures will be estab-lished in accordance with our vendor's recommended guidelines to include the re-quirement to initiate auxiliary feed-water flow within the first ten (10) minutes following a LOCA.
One of the two control room operators will initiate auxiliary feed-water flow within 10 minutes of a LOCA.
Analyses shows that auxiliary feed-water flow is not required for 15-16 minutes.
Having an additional operator in the control room to perform a specific duty appears to be in violation of staff recommendations following the TMI incident to keep the control room orderly and well supervised.
The more people in the control room with authority to operate controls, the more difficult it becomes for the control room commander to supervise control of the reactor.
Therefore, we conclude that two licensed control room operators can perform all immediate actions required to place the reactor in a safe condition provided these actions are specified in pro-cedures.
In accordance with the NRC Bulletins and Orders Task Force, we are proceeding with analyses to support procedure guidelines.
Once these guidelines are available, our procedures will be revised.
Then we must rely on NRC licensed operators to perform the required procedural actions.
Item 6. b Your response to Item 6.b appears to be inadequate; therefore, provide assurance that operating procedures will be modified to keep high pressure injection and charging pumps in operation in accordance with the criteria specified in item 6.b of the bulletin and as clarified by the.following statement:
"After 50F subcooling has been achieved, termination of high pressure safety in-jection (HPI) operation prior to 20 minutes is only permissible if it has been determined that continued operation would result in an unsafe plant condition, e.g.,
attaining pressure/temperature conditions that could jeopardize vessel integrity or that could have the potential for opening the PORVs or safety valves so as to discharge water or a two-phase fluid consistng of water and steam."
4 Provide a schedule for completion of the review of operating procedures incorpor-ating such modifications as are necessary to comply with item 6.b of the bulletin.
Response
Consumers Power Company has spent countless hours trying to convey our safety con-cern to the NRC that running these pumps for 20 minutes once safety injection has been reset will result in filling of the quench tank.
We have a procedure (Primary Coolant System Depressurization (D4.34)) which allows us to reset safety injection and secure the HPSI and charging pumps if the follow-ing conditions are met:
- a.
The cause of the low-pressure condition is known and corrected.
- b.
The reactor is shut down and will remain shut down.
- c.
Pressurizer level is greater than 20% and is returning to normal.
- d.
Tavg is stable or increasing and is less than 545°F.
- e.
PCS pressure is greater than 1700 psi and is returning to normal.
This procedure allows us to secure the safety injection system in the case of "inadvertent actuation of safety injection" as discussed in the vendor's procedure guidelines on LOCA.
We have been required by the NRC letter dated June 5, 1979 to form an Owners' Group, perform analyses on LOCAs and develop procedure guidelines.
We have followed this course of action to the letter and now expect to be able to use the results of our efforts.
We define "inadvertent actuation" to mean any event, not a LOCA, which causes pri-mary system pressure to drop below the safety injection actuation signal but no lower than the HPSI pump shutoff head of 1250 psig.
Item 1 Your response regarding periodic checks* of positions of unsecured valves is not acceptable.
We request that you modif'y your procedures to require checks of the positions of unsecured valves monthly.
Response
Consumers Power Company will commit to locking all unsecured valves in engineered safety feat-ures systems which are not tested monthly.
The locks will be installed by January 1, 1980.
Item 9.a Your letters of April 27 and June 5, 1979 indicate that you test redundant equip-ment and do not perform an entire redundant system check prior to removal of any safety related component from service.
Provide assurance that the testing per-formed acceptably assures that the redundant safety system will be operable.
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Response
We test our engineered safety features systems in different ways, such as flow testing, valve lineups and load testing.
For each engineered safety feature system, our testing acceptably assures that the redundant safety system will be operable.
David P Hoffman (Signed)
David P Hoffman Assistant Nuclear Licensing Administrator CC Director, Office of Nuclear Reactor Regulation Director, Office of Inspection and Enforcement