ML20008G349
| ML20008G349 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 06/24/1981 |
| From: | Linder F DAIRYLAND POWER COOPERATIVE |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-TM LAC-7624, NUDOCS 8107070346 | |
| Download: ML20008G349 (3) | |
Text
,
DlDA/RYLAND h
[k COOPERAT/VE eo Box 8i7 2615 EAST AV SOUTH LA CROSSE. WISCONSIN 54601 (608) 788 4 000
)
June 24, 1981 In reply, please refer to LAC-7624 DOCKET NO. 50-409 U. S. Nuclear Regulatory Commission ATTN:
Mr. Darrell G. Eisenhut, Director g
g Division of Licensing Office of Nuclear Reactor Regulation D
Division of Operating Reactors rp,f lli i
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Washington, D. C.
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SUBJECT:
DAIRYLAND POWER COOPERATIVE N b 'l LA CROSSE BOILING WATER REACTOR (LACBWR)
Eh"MsT 8
W PROVISIONAL OPERATING LICENSE NO. DPR-45 4
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POST TMI REOUIREMENTS (ITEM II. B.1) '
N/
References:
(1)
NUREG-0737, NRC Letter, Eisenhut to All Operating Reactors, dated October 31, 1980.
(2)
NRC Letter, Eisenhut to All Operating Nuclear Power Plants, dated September 13, 1979.
(3)
NRC Letter, Denton to All Operating Nuclear Power Plants, dated October 30, 1979.
(4)
DPC Letter, Linder to Denton, LAC-6616, dated November 5, 1979.
(5)
DPC Letter, Linder to Denton, LAC-6680, dated December 6, 1979.
(6)
NRC Letter, Ziemann to Linder, dated April 25, 1980.
(7)
NRC Letter, Heishman to Linder, dated June 5, 1980.
(8)
NRC Letter, Heishman to Linder, dated May 13, 1981.
Gentlemen:
Your letter (Reference 1), Item II.B.1, requested information on reactor coolant system vents.
The initial requirement on venting was established in References 2 and 3.
Information was provided on reactor coolant vents to the NRC staff in References 4 and 5 and during a staff visit to LACBWR on March 19 and 20, 1980.
In Reference 6, the NRC concluded that LACBWR had satisfactorily met $hO Ob g
P
n Mr. Darrell G. Eisenhut, Director LAC-7624 Division of Licensing June 24, 1981 some Category A requirements and the requirement for Reactor Coolant System High Point Vents in that "The Manual Depressurization System at La Crosse currently provides a safety grade venting system".
The letter stated that verification of the adequacy of procedures for use of the venting system would be performed by the Office of Inspection and Enforcement and would be documented in an appropriate inspection report.
IE Inspection Report No. 50-409/80-01 (Reference 7) documented the inspector's review of operating and emergency pro-cedures for venting the reactor and concluded they were adequate.
Reference 8 summarized the foregoing correspondence, inspections and acceptable actions.
Reference 1 did introduce several new requirements.
Our position with regard to these additions is addressed as follows:
j One of the new requirements is that the probability of a vent path failing to close, once opened, should be minimized and that a single failure within the power and control aspects of the reactor coolant vent system should not prevent isolation of the entire vent system when required.
Loss of power to either of the two Reactor Emergency Flooding Vent Valves (62-25-013 and 62-25-014), comprising the Manual Depressurization System, would cause the valve to fail closed.
One valve's solenoid is powered from the Reactor Building 125 Volt DC Bus, which is normally supplied by the Reactor Building Battery Charger, with the Reactor Building Battery as a reserve, while the other's is powered by the 1B 120 Volt AC Noninterruptible Bus, which the Diesel Building Bettery or 1B Emergency Diesel Generator can supply upon loss of power.
Loss of nitrogen would cause the Reactor Emergency Flooding Vent Valves to fail open, but the valves could then be isolated from the reactor by closing the Shutdown Condenser Inlet Valves, which are air operated.
l The Shutdown Condenser Off-Gas Valve (62-25-003) would fail closed on loss of control air or power to its solenoid.
There are also two normally locked open isolation valves, one on either side of the Shut-i down Condenser Off-Gas Valves.
Therefore, the probability of a failure preventing a vent from being closed once opened is minimal.
NUREG-0737 adds the requirement that the reactor coolant vent system be environmentally qualified.
The Manual Depressurization System will be modified to meet this requirement by June 30, 1982.
Plans are also being initiated to modify the control circuit for the Shut-down Condenser Off-Gas Vent to enable it to comply with the environ-ment qualification requirement. -
Mr. Darrell G. Eisenhut, Director LAC-7624 Division of Licensing June 24, 1981 Reference 1 also requires that testing be performed on the reactor coolant vent system in accordance with subsection IWV of Section XI of the ASME Code for Category B valves.
The Reactor Emergency Flooding Vent Valves are being tested in accordance with subsection IWV of Section XI of the ASME Code for Category B valves and the Shutdown Condenser Off-Gas Valve is being tested as a Category A valve.
The final additional requirement in Reference 1 is that BWR licensees compare their specific design features with the generic venting capa-bility proposed by the BWR Owners Group.
Since'LACBWR is an Allis-Chalmers Boiling Water Reactor, rather than a GE BWR, systems vary considerably.
LACBWR does have three mechanical relief valves in the main steam line.
LACBWR does not have a dry well, a normally open reactor head vent line, RCIC or HPCI.
Therefore, LACBWR's venting capability cannot be directly compared with the generic venting capability proposed by the BWR Owners Group.
LACBWR's Manual Depressurization System and Shutdown Condenser Off-Gas Vent Valve must be evaluated on their own merits.
As mentioned earlier, the NRC staff has already concluded LhCBWR's capability and procedures meet the original criteria.
The additional require-ments specified in NUREG-0737 have been' addressed in this letter.
LACBWR has or will meet these additional requirements also.
If there are any questions regarding this letter, please let us know.
Very truly yours, DAIRYLAND pO R COOPERATIVE e
h v l
Frank Linder, General Manager i
l FL:LSG:af cc:
J. G. Keppler, Reg. Dir., NRC-DRO III NRC Resident Inspectors l -
-.