ML20003D361

From kanterella
Revision as of 14:12, 23 December 2024 by StriderTol (talk | contribs) (StriderTol Bot insert)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
Inquiry Rept 50-029/73-02Q:on 730504,during Startup,Three Protective Sys Pressure Switches Failed to Actuate Per Tech Specs Requirement.Caused by Leak in Turbine First Stage Pressure Sensing Line.Reactor Scram Will Be Attempted
ML20003D361
Person / Time
Site: Yankee Rowe
Issue date: 05/15/1973
From: Oberg C
US ATOMIC ENERGY COMMISSION (AEC)
To:
References
50-029-73-02Q, 50-29-73-2Q, NUDOCS 8103261105
Download: ML20003D361 (2)


Text

= = - ^

se. -

s~

n r

UNITED STATES

~9[ g n g*+,,

ATOMIC ENERGY COMMIEJ'ON q

DIR ECTOR ATE OF NL4,U L ATOR Y OPE N ATIONS i

,f REGION 9 "f

970 BRO AD 5TREET f

NEwAnx, r!Ew JEnsEY 07102 RO Inquiry Report No. 50-29/73-02Q

[

Licensee:

Yankee Atomic Electric Company T

20 Turnpike Road I

Westboro, Massachusetts 4

License No.:

DPR-3 I

Facilitys Yankee - PWR Rowe, Massachusetts

Title:

Operating Reactor at Power Without Required i

Protective Trips (Violation of Technical Specifications) t Prepared by:

IM

%, /[ /'M C. R. Oberg, Reactor Inspector Date l

A.

Date and Manner AEC was Informed:

l By telephone call from licensee on Iby 4,1973.

B.

Description of Particular Event or Circumstance:

i During a, plant startup (af ter a scram from power) on May 3,1973, three

}

protective system pressure switches were not actuated as required by I

i Technical Specifications, paragraph D.2.d. (2). These pressure switches

}

are normally actuated by turbine first stage pressure and insert, j

at a pressure setting equivalent to 15 MWe, the following automatic protective features through permissive relays:

)

f 1.

Main coolant low flow trip.

2.

Steam generator low level trip 3.

Turbine trip 4.

Generator trip 1

Relay actuation is indicated by lights on the main control board.

Automatic low coolant pressure and low pressurizer 1cvel trips were availabic throughout the event.

1 i

t

- ~.

.- =~-.

~.

l-i 1

l f

2-e i

l The licensee stated that the loading of the plant continued past the 15 MWe point without the above automatic protection.

The a

pressure switches were ultimately actuated at a turbine pressure

}

equivalent to 30 - 33 FE'e for the reactor permissive relays and 25 - 30 FMe for the turbine generator permissive relays.

The i,

abnormal relay operation was suspected to.be caused by a leak in the turbine first stage pressure sensing line within the turbine casing.

The licensee stated that a Westinghouse turbine representative had been called in to evaluate this problem. The licensee further l

stated that this problem was known prior to the plant starting.,

on May 3, 1973, that the Westboro management - engineering office I

was informed of the problem, and that the decision to continue operation was based on that office's desire to collect first stage steam pressure data in order to recalibrate the pressure switch.

Power operation of the plant is continuing within the allowable j

license limits.

l C.

Action by Licensee:

1.

Orders have been issued by the licensee to: (a) scram the l

reactor from the point where automatic protection is lost

]

j (when shutting down), and (b) if a reactor scram occurs, the reactor will not be started up until the problem is resolved.

j

~

7; 2.

In addition, the licensee plans to request a change to the j

reactor protective system which.will have the pressure switches sense pressure from a different location which would be more indicative of actual power level of the turbine generator.

-l 3.

The licensee will submit a 10 day trritten report on the vio-lation to the AEC.

e i

}.

t 4

i E

i*

3-

-m aw, y

eg.

y.---m=

g-w y.

--w-g q r w

+1.*rw