(June 25, 1993) Instruments used to measure water levels in Boiling Water Reactors (BWRs) may produce readings that are off by as much as 27 feet, according to new tests. Stunned by the revelation, the US Nuclear Regulatory Commission (NRC) has ordered US utilities to improve their monitoring abilities by 15 June, and to begin implementing permanent modifications during their first outages after 30 July.
(393.3837) WISE Amsterdam - To no one's surprise, though, says the Nuclear Information& Resource Service (NIRS), the NRC stopped short of closing the plants until the instruments are functional.
NIRS, a Washington-based public interest group, says the problem is that condensate pots used with the monitors become blocked by gas bubbles. The monitors then read the information incorrectly, resulting in readings that may show the reactor vessel is full of water, when in fact it is emptying. The misreadings could cause problems both for automatic safety systems and for plant operators.
Earlier, when the problem was first noticed, utilities and the BWR Owners Group (BWROG) claimed that the instruments would be off only by a few inches and that would not be enough to affect safety systems or operator performance. But recent tests - which the BWROG and the General Electric Corp. (manufacturer of BWRs) tried to have declared "proprietary" - revealed that the instruments could be wrong by 324 inches, or 27 feet.
In January, instruments failed to detect a water-level drop during a routine shutdown at the WPPSS-2 BWR in Washington State, heightening safety concerns. But existence of the problem had been revealed earlier by Paul Blanch, a former Northeast Utilities executive. Blanch had been asked by the NRC to investigate an incident at the Pilgrim reactor last May. He quickly realized the problem was generic and significant, and just as quickly ran into a brick wall trying to solve it:
After he made the problem public knowledge, Blanch was intimidated and harassed by Northeast Utilities; the NRC issued a violation to North-east for the problem even though, be-cause of Blanch, it was the only utility actually working to address the issue; and an NRC official publicly said that "Blanch violated Commission rules."
Ultimately, Blanch resigned from Northeast after working more than 20 years for the utility, and his complaints of harassment and intimidation were upheld by the NRC, which fined the utility. In June, in testimony on behalf of himself and We the People, a group that works to support "whistleblowers" (employees who report company wrongdoing), Blanch told the NRC commissioners that "a reasonable individual could conclude a less than open atmosphere exists between the public and the NRC, and that a very cozy relationship still exists between the NRC and the nuclear industry. This cozy relationship is hindering the free flow of significant safety information between the NRC, interested public and possibly other licensees." He noted, for example, that General Electric's and the BWROG's attempt to keep the damaging test results proprietary "with the only apparent intent being to keep this information from the public."
Blanch added that the NRC's Advisory Committee on Reactor Safeguards (ACRS) met with the BWROG in closed session to discuss the results and it was "only because an ACRS member mentioned after the closed session the error was 27 feet [that I was] able to determine the significance of this potential level error."
Source: The Nuclear Monitor (US), 7 June 1993, p.1.
Contact: NIRS, 1424 - 16th Street NW, Suite 601, Washington DC 20036, USA
tel: + 1-202-328-0002.