United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for March 11, 1999

                       Headquarters Daily Report

                         MARCH 11, 1999

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                    REPORT             NEGATIVE            NO INPUT
                    ATTACHED           INPUT RECEIVED      RECEIVED

HEADQUARTERS                           X
REGION I            X
REGION II                              X
REGION III                             X
REGION IV           X
PRIORITY ATTENTION REQUIRED  MORNING REPORT - REGION I  MARCH 11, 1999

Licensee/Facility:                     Notification:

Public Service Electric & Gas Co.      MR Number: 1-99-0010
Hope Creek 1                           Date: 03/11/99
Hancocks Bridge,New Jersey             SRI PC
Dockets: 50-354
BWR/GE-4

Subject: CONTROL ROD BLADE BLISTER AT HOPE CREEK

Discussion:

During a planned refueling outage visual inspection, Public Service and
Electric Gas Company (PSEG) identified a blister on an ABB (Asea Brown
Boveri) Model CR82 control rod blade. The blistered control rod was the
center control rod and had been fully inserted and disarmed for
approximately the last ten months of Hope Creek's operating cycle. The
control rod had been fully inserted into the core in March 1998 after
difficulty in withdrawing the control rod for a rod pattern adjustment.
Hope Creek is replacing the blistered control rod blade and continuing
blade inspections.

An ABB vendor representative was present during the visual inspections
and ABB is evaluating the cause and significance of the CRB blister in
accordance with 10 CFR 21.

Regional Action:

None.

Contact:  G. Meyer                   (610)337-5211
          D. Orr                     (609)935-3850
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REGION IV  MORNING REPORT     PAGE  2          MARCH 11, 1999

Licensee/Facility:                     Notification:

Arizona Public Service Co.             MR Number: 4-99-0010
Palo Verde 1                           Date: 03/11/99
Wintersburg,Arizona                    From SRI
Dockets: 50-528
PWR/CE80

Subject: AUTOMATIC REACTOR TRIP IN UNIT 1 (EVENT 35456)

Discussion:

On March 10, 1999, at 1:26 p.m. MST, Palo Verde Unit 1 experienced an
automatic reactor trip as the result of high pressurizer pressure. Prior
to the trip, the throttle pressure limiter circuit in the
electrohydraulic control system failed, causing two turbine control
valves to close. Consequently, the steam bypass system valves opened to
control pressure in the main steam lines. The operations staff, believing
the bypass valve control circuitry had experienced a fault and opened
inadvertently, incorrectly placed the bypass valve control switch in the
emergency off position to close the valves. Closing the valves caused
main steam header pressure to increase, which caused two main steam
safety valves to lift and resulted in a corresponding increase in primary
system pressure. Due to the mismatch between reactor power and secondary
system demand, the pressurizer pressure high setpoint was reached and
there was an automatic reactor trip. Following the reactor trip, a
postevent review indicated that two main steam safety valves may have
prematurely lifted. The licensee is continuing to investigate whether the
lifts were premature.

At approximately 2:29 p.m. MST, a main steam isolation system signal
occurred due to a high water level in Steam Generator 2. The high water
level condition occurred when the operations staff attempted to place the
steam generator level control system in automatic to maintain level.
After initiating automatic control, a failure in the level control
circuitry resulted in the level increasing. The operator took manual
control and closed all main feedwater isolation valves. Since a large
volume of relatively cold water had been placed in the steam generator
before feedwater was isolated, when this water heated up, it caused a
main steam isolation signal to be generated on a high level. In response,
the operations staff started the emergency feedwater system and removed
decay heat by the use of the secondary system atmospheric dump valves.

The licensee has repaired the equipment anomalies identified with the
throttle pressure limiter circuit and the steam generator level control
system. The unit is currently in Mode 3, with an anticipated return to
power operations on March 12, 1999.

Regional Action:

Routine followup by the resident staff is ongoing.

Contact:  Jim Moorman                (602)386-3638
          Phil Harrell               (817)860-8250
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