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U.S. Reactors
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   CRACII: Reactor Accident Study
   Terrorism at Nuclear facilities
California Reactors
    40 Years of California Activism
    Nuclear Energy in California
   The California Ballot Issue
Rancho Seco
   Rancho Seco Timeline
Diablo Canyon
    Diablo Canyon Timeline Part I:
    Diablo Canyon Timeline Part II:
    Diablo Canyon Settlement
    PG&E financial Statements
    Coast & Ocean Autumn 1999-1
    Environmental Working Group
    Myth:Diablo Blockade
    Rate Case and Litigation Support
    Severe Accident Cost Estimates
    Bonnie Raitt: Benefit Appearances Diablo Canyon
    DOE: Annual Reports
    WLA:Engineering Projects
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    Enercon Services, Inc. Links
    Index PIX
    Yahoo: Atomic justice Message
    NE 267
    D.97-08-056 D.97-08-056
    The Anti-Nuclear Movement
    PG&E Environmental Report
    ROADWHORE: Nuclear

The History of Rancho Seco


SMUD purchases 2,100 acres in southeast Sacramento County for a nuclear power plant. Construction begins on the cooling towers.


  • SMUD raises rates...even though Rancho Seco hasn't produced a single kilowatt-hour of electricity.
  • The day Rancho Seco is dedicated there is a forced shutdown of the reactor (unknown to those attending the dedication ceremony)... a portent of things to come. [10/19/74]
  • The turbine breaks down. The plant is shut down for 13 of the first 18 months of operation.


  • Loose parts are found in Rancho Seco's generator. SMUD says the find "will not cause any additional lost time." The plant is down for six months. [4/9/76, SB ]


  • Rancho Seco shuts down four times. Problems are due to a dangerously fast cooldown.


  • Radioactive iodine is found in milk from cows grazing near Rancho Seco. [Quarterly Radiation Report on Rancho Seco ]


  • Rancho Seco shuts down six times. Problems occurred with pipe supports, reactor coolant leaks, malfunctions, turbine bearings and feedwater flow. [9/26/83, SU ]
  • SMUD is fined $25,000 by the NRC for violating federal safety standards.


  • A state report on emergency planning estimates that a serious nuclear accident at Rancho Seco could result in as many as 76,000 deaths and 110,000 injuries. [11/2/80, SB ]
  • Rancho Seco shuts down 12 times. Problems are due to steam generator tube leaks, feedwater, reactor coolant pump and turbine vibrations. [9/26/83, SU ]


  • Rancho Seco shuts down 11 times, due to problems with the turbine, steam leaks, oil pressure and reactor trips. [9/26/83, SU ]
  • SMUD is fined $120,000 for violating federal safety regulations.
  • The steam generator leaks again...more radioactive steam escapes. Another shut-down.


  • Rancho Seco shuts down five times, due to maintenance, re-fueling, modifications, oil pressure in turbine generator, heat imbalance in reactor and leak in steam generator tube. [9/26/83, SU ]
  • The steam generator tubes leak again and more radioactive steam escapes into the atmosphere. The plant is shut down again.
  • SMUD faces a lack of skilled workers for Rancho Seco. [3/6/83, SB]


  • Rancho Seco is on the NRC's list of the ten worst nuclear plants in the U.S. in overall assessment of management performance. [3/28/89, Public Citizens Mishaps Report, NRC ]
  • More than two billion gallons of water containing radiation levels above federal guidelines have been dumped from Rancho Seco into a creek that feeds the Cosumnes and Mokelumne Rivers, SMUD officials confirmed. [4/14/84, SB ]
  • Two workers are killed by high-pressure steam bursting from a boiler at Rancho Seco.
  • An explosion and fire shut down Rancho Seco for 38 days.


  • SMUD raises rates nearly 30 percent. SMUD has the first budget deficit in its history. From January 1, 1985 to March 31, 1988, Rancho Seco operates only three months (out of three and one-quarter years).
  • On December 26, Rancho Seco suffers thethird-fastest shut-down in U.S. reactor history when a control circuit malfunctions. The sudden temperature change could have cracked the reactor vessel and led to a meltdown.
  • SMUD customers are now paying 40 percent more than a year ago. Rancho Seco work is $27 million over budget and another rate increase is being considered.


  • Sacramentans for SAFE Energy (SAFE) calls for the SMUD board of directors to commission an independent, comprehensive study of the safety and economic risks associated with Rancho Seco as well as a comparison of alternative means of meeting our energy needs.
  • Rancho Seco assistant manager for nuclear operations Dan Whitney said plant managers sometimes deliberately withheld information about system shortcomings when questioned by the NRC. [5/22/86, SB ]
  • SMUD admits that Rancho Seco was "mismanaged, mismaintained and misoperated" its entire lifetime. [5/20/86, SB ]
  • Two Rancho Seco workers are fired for drug abuse. They claim there is drug abuse throughout the plant.


  • wo water leaks lead to the release of approximately 10,000 gallons of radioactive water, some of it flowing into the nearby creek, outside of the plant's boundaries...[3/28/89, Public Citation of Mishaps, NRC ]
  • In 1987, SMUD pays more than $350,000 in cash bonuses to fill positions at Rancho Seco. [7/10/88, SB ]
  • "Rates have increased 84 percent since March 1985, leading to ratepayer dismay and a situation in which half of SMUD households pay more than if served by surrounding Pacific Gas and Electric Company. " [10/23/87, SB ]
  • Chief of nuclear operations, John Ward, is fired despite reputation as a fixer of hopeless cases."It was like being in charge of the Keystone Kops," says Ward. [9/23/86]


  • "Closing Rancho Seco is the option for the future of SMUD that makes the most sense." [3/2/88, Sacramento Bee Editorial Staff ]
  • "The never-ending series of mishaps are beginning to look like a very high-budget Marx Brothers film, with Harpo in charge of warning the city should there be an emergency." [2/19/88, TV 40 Editorial Comment ]
  • A SMUD-commissioned, $824,000 QUEST study team recommends closure of Rancho Seco, saying that unstable operation of Rancho Seco could bankrupt SMUD.
  • Rancho Seco operates at less than 37%--even less than its lifetime capacity average of 39%. Rates have increased almost 92% since March 1985 due to Rancho Seco problems. [INPO ]
  • The October 1988 SMUD bond prospectus states, "The District has concluded that terminating Rancho Seco in June 1989 would not have a materially adverse impact on the District's operations through December, 1999." [SMUD ]
  • Measure B (to close Rancho Seco) loses on the June ballot by the narrowest of margins--only two votes per precinct. Measure C (to give Rancho Seco a trial run) barely passes.
  • Rancho Seco supporters promise stability and low electric rates for SMUD. However, immediately following the June 1988 election, SMUD General Manager Richard Byrne is fired, Rancho Seco chief of nuclear operations resigns and SMUD discloses the need for additional rate increases. Two SMUD chiefs get $520,000 in severance pay and bonuses.
  • Former SMUD general manager Richard Byrne said he was "stifled, pressured and threatened by pro-Rancho Seco board members who wanted to keep potentially damaging information from reaching the public before the June 7, 1988 election. [6/18/88, SB ]
  • SMUD gives out $248,500 in bonuses to middle- and upper-level employees in May for ''extraordinary service.'' About 80 percent ($197,000 was awarded to Rancho Seco managers and the balance to employees at SMUD headquarters. [9/1/88,SB]
  • SMUD secretly paid out more than 970,000 in cash and benefits to eight managers who were forced to leave the utility during the past two years. [11/17/88, SB ]
  • Operating Rancho Seco in 1988 cost nearly twice the amount it would have cost SMUD to have purchased the same amount of electricity from other utilities. [12/26/88, SU ]
  • December 12--Operators try to restart Rancho Seco with malfunctioning valves. They rig the system in a manner for which there are no written procedures. One of two steam generators runs dry. NRC officials say operators took the plant through "uncharted waters" and showed poor judgment in handling the restart.


  • On January 31 Rancho Seco shuts down. Two days later, radioactive gas is released into the environment. The plant is down for 45 days. Bill Chapin, Rancho Seco plant mechanical maintenance supervisor and co-chairman of the Rancho Seco Political Action Committee says, "I think there's no doubt, the Ranch cannot have another breakdown between now and June, politically speaking." A day after his quote, Rancho Seco goes down yet another time. [3/28/89, SB ]
  • SMUD and PG&E contract ensures cheap, reliable power for Sacramento through l999. [2/27/89, SU ]
  • The nuclear industry's own Institute of Nuclear Power Operations prepares a report on the recent shutdowns at Rancho Seco, saying that Rancho Seco's prior operating history as well as recent shutdowns "cause us to have a renewed concern over the quality of Rancho Seco operations." [INPO]
  • SMUD pays $1,230 for one Rancho Seco employee's clothing as part of the "distinctive attire'' program. Jackets, pants, shirts and ties have already cost $72,000; laundry bills, $2,500 a month--all ultimately paid by the ratepayers.
  • The plant comes to an abrupt halt (is scrammed) on the 10th anniversary of the Three Mile Island meltdown. High-level radioactive gasses are vented to the atmosphere. On April 8 the reactor is started, even though the cause of the March 28 accident has not been found and malfunctioning equipment (from the March 15 accident) has not been repaired. [3/29/89, SB, SU ]
  • June 6th, 1989 Sacramento Citizens go to the polls and vote to permanently close Rancho Seco.

Sources: SB: Sacramento Bee, SU Sacramento Union xxx The above was a poster created for Measure K on June 6, 1989