0CAN098807, Responds to NRC Bulletin 88-004, Potential Safety-Related Pump Loss. Submits Response to Questions 1 & 2.Evaluation of Question 3 Underway,Requires Addl Data from Mfg Re Min Flow for Pump Protection.Response Expected in Feb 1989
| ML20154J272 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 09/06/1988 |
| From: | Howard D ARKANSAS POWER & LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 0CAN098807, CAN98807, IEB-88-004, IEB-88-4, NUDOCS 8809220301 | |
| Download: ML20154J272 (5) | |
Text
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AAKANSAS POWER & LIGHT COMPANY September 6, 1988 BCAN098807 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station P1-137 Washingtor), DC 20555
SUBJECT:
Arkansas Nuclear One - Units 1 & 2 Docket Nos. 50-313 and 50-368 License Nos. DPR-51 and NPF-6 NRC Bulletin No. 88-04:
Potential Safety Related Pump Loss Gentlemen:
Your letter of May 5, 1988 (0CNA058804) requested a response to NRC Bulletin No. 88-04:
Potential Safety Related Pump Loss.
In our letter of July 5, 1988 (0CAN078803), Arkansas Power and Light Company (AP&L) committed to provide a response by September 6, 1988.
Attached is our response to questions #1 and #2. Question #3 required AP&L to evaluate the adequacy of the minimum flow bypass lines on our safety-related centrifical pumps.
This evaluation is currently underway and requires contacting the pump manufacturers and requesting data from them in regard to the minimum flow for pump protection.
This information is expected to be received within the next few months.
Evaluation of the data received, possible calculations, and additional testing, if required, extends ou: expected response date for this item to February,1989.
Very tr ly yours,
/ 41 Dan R. Howard Manager, Licensing DRH:MCS:de Attachments l
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STATE OF ARKANSAS
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SS COUNTY OF PULASKI
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I, Dan R. Howard, being duly sworn, subscribe to and say that I am Manager, Licensing for Arkansas Power & Light Company; that I have full authority to execute this oath; that I have read the document numbered DCAM098807 and know the contents thereof; and that to the best of my kno'< ledge, information and belief the statements in it are true.
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Dan R. Howard SUBSCRIBE 0 AND SWORN TO before me, a Notary Public in and for the County and State above named, this ]p
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- 1988,
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Notary Public My Ccmission Expires:
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OVESTION NO. 1 Promptly determine whether or not its facility has any safety-related system with a pump and piping system configuration that does not preclude pump-to pump interaction during miniflow operation and could therefore result in dead-heading of one or more of the pumps.
RESPONSE
ANO-1 The bulletin concern was reviewed for applicability to the safety-related centrifugal pumps in ANO-1.
These pumps are:
Pump No.
Pump Name P-7 A & B Emergency Feedwater P-34 A & B Decay Heat Removal /LPSI P-35 A & B Reactor Building Spray P-36 A, B & C Primary Makeup /HPSI A review of the piping systems for the above pumps has determined that pump to pump interaction during miniflow operation will not result in dead heading of one or more pumps.
A summary of each pump's miniflow recirculation piping system is as follows:
P-7 A & B - Emergency Feedwater (EFW) Punps Each EFW pump's miniflow recirculation line originates at the pump discharge automatic recirculation control valve as a 2" line.
A flow orifice follows and then the line size is :ncreased to 4".
Both miniflow recirculation lines join with the line size maintained at 4".
The miniflow then continues to either the condenser or condensate storage tank.
The flow orifica and line size increase prior to the miniflow recirculation lines joining prevents either pump from being dead headed by the other.
P-34 A & B - Decay Heat Removal (DHR) Pumps /LPSI Each DHR pump has an independent minitlow recirculation line originating on the downstream side of the decay heat coolers.
A flow orifice is present prior to the 2" line returning to the pump suction.
The presence of independent miniflow recirculation lines precludes any pump to pump interaction.
1
P-35 A & B - Reactor Buildino Spray Pumps Neither reactor building spray pump has a miniflow recirculation line.
Pump protection is handled admin ttratively by low flow alarms which would alert the operator when flow is not detected in the containment spray discharge line.
P-36 A. B & C - Primary Makeup Pumps /HPSI, Each primary makeup pump miniflow recirculation line originates at the pump discharge.
A flow orifice is present in each 2" line prior to the lines joining at a common 2" header.
The 2" header continues to the seal return molers and then to the reactor coolant makeup tank which supplies the pump suction.
4 The flow orifice present in each pump's miniflow recirculation J
line prior to the lines joining the header prevents the dead heading of one or more pumps by another.
ANO-2 The bulletin concern was reviewed for applicability to the safety-related centrifugal pumps in ANO-2.
These pumps are:
Pump No.
Pump Name 2P-7 A & B Emergency Feedwater Pumps (EFW) i 2P-39 A & B Boric Acid Makeup Pumps (BAM) 2P-35 A & B Containment Spray Pumps (CS) 2P-60 A & B Low Pressure Safety Injection (LPSI) j J
2P-89 A, B & C High Pressure Safety Injection (HPSI) 2 A review of the piping systems for the above pumps has determined that pump to r ump interaction during miniflow operation will not result in ds.d heading of one or more pumps.
A sunnary uf each pump's miniflow recirculation piping system is as follows:
2P-7 A & B - Emergency Feedwater Pumps Each EFW pump has a miniflow recirculation line originating as a 2" line at the plt.,p discharge.
A flow orifice is installed in each line prior to them joining a 4" header and continuing to the condensate storage tank.
The flow orifice installed prior to the 2" lines joining the 4" header and the increase in line size prevents either punt from being dead headed t'y the other.
2
c t
r v, o cs are present in the EFW pump discharge piping prior to
,e< the miriflow recirculation line which could allow pump
.ceraction.
However, the manual valves installed in the
.a o
t<: 4 sonnects are administrative 1y controlled and locked closed.
These valves are not used for normal operation or used in the ANO-2 Emergency Operating Procedures.
Therefore, the miniflow recirculation lines are considered irdependent and pump to pump interaction which could result in dead heading is prevented.
2P-39 A & B - Boric Acid Makeup Pumps Each BAM pump has an independent miniflow recirculation line originating at the pump discharge as a 2" line continuing to the boric acid makeup tank.
The presence of independent miniflow recirculation lines precludes any pump to pump interaction.
2P-35 A & B - CS Pumps 2P-60 A & B - LPSI Pumps 2P-89 A, B & C - HPSI Pumps Each of these pumps miniflow recirculation line originates at the respective pump's discharge and contains a flow orifice.
Each 2" line ties into a 4" header downstream of the flow orifices.
The 4" header ties into a 6" line which continues to the refueling water tank.
The flow orifice installed prior to the 2" lines joining the 4" header and the line size increase prevents any pumps from being dead headed by other pumps.
QUESTION NO. 2 If the situation described in Item 1 exists, evaluate the system for flow division taking into consideration (a) the actual line and component resistances for the as-built configuration of the identified system; (b) the head versus flow characteristics of the installed pumps, including actual test data for "strong" and "weak" pump flows; (c) the ef fect of test instrument error and reading error; and (d) the worst case allowances for deviation of pump test parameters as allowed by the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code)Section XI, Paragraph IWP-3100.
RESPONSE
The situation described in Bulletin 88-04 is not a concern at Arkansas Nuclear One, Units 1 and 2; therefore, this question is not applicable.
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